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Dried distiller grains with solubles (DDGS) are a popular byproduct used in the livestock feed industry as it is a cost-effective feedstuff that is rich in crude protein and minerals. However, a common concern related to the use of DDGS in livestock diets is the negative impact that affects animal dry matter intake (DMI) and growth. To further investigate this challenge, the experiments aimed to evaluate the effect of feeding 1) two different diets, control versus heat processed DDGS or 2) increasing the concentration of DDGS and its effect on body weight (BW), average daily gain (ADG), DMI, and gain to feed ratio (G:F) in finishing lambs. In experiment 1, both diets were the same except for the heat processing of DDGS; the control diet used a commercial DDGS source directly from the supplier and the processed diet contained the same commercial DDGS source that differed through additional heat processing. For DDGS heat processing, 40% moisture was added to the DDGS and heated at 150 °C for 70 min. After the heating process, the DDGS was placed in a second oven at 56 °C for 2 d to allow for humidity evaporation. Lambs (n  = 34), blocked by sex and BW, were housed in pens (2 to 3 lambs/pen, 6 pens/treatment) and were fed for 42 d. Lamb DMI was measured daily, and BW was measured every 14 d. In experiment 2, lambs (n = 75) were blocked by BW (5 lambs/ pen, 5 pens/treatment) and fed diets differing in inclusion rates of DDGS (10%, 20%, and 30%). The feeding period lasted for 56 d, and lamb DMI and BW were measured daily or every 28 d, respectively. In both experiments, diets were isonitrogenous, and the feeding procedure utilized slick bunk management. Data were analyzed in SAS using a mixed model considering the treatments as fixed effects and pen and block as random effects. In experiment 1, there were no treatment differences (P  ≥ 0.13) in ADG, DMI, and G:F in finishing lambs. In experiment 2, a linear and quadratic contrast were used to separate the mean and demonstrated that increasing the concentration of DDGS decreased lamb DMI (linear P  < 0.01; quadratic P  = 0.05), but did not affect lamb BW, ADG, or G:F (P  ≥ 0.26). Despite that previous research shows differences in animal growth because of an increase in DDGS concentration, our experiments illustrated that heat processing or increased concentrations of DDGS up to 30% in finishing lamb diets are not responsible for a decrease in lamb performance. [ABSTRACT FROM AUTHOR]

Poor maternal nutrition of F0 ewes impairs F1 offspring growth, with minimal differences in glucose tolerance or select metabolic circulating factors, and independent of differences in residual feed intake (RFI). To determine if poor maternal nutrition in F0 ewes alters F2 offspring growth, circulating leptin, feed efficiency, or glucose tolerance, F0 ewes (n  = 46) pregnant with twins were fed 100% (control), 60% (restricted), or 140% (over) of National Research Council requirements from days 30 ± 0.02 of gestation until parturition. At 16 to 19 mo of age, female F1 (n  = 36) offspring were bred to generate F2 offspring [CON-F2 (n  = 12 ewes; 6 rams), RES-F2 (n  = 7 ewes; 13 rams), or OVER-F2 (n  = 13 ewes; 9 rams) corresponding to diets of the granddam (F0)]. Lamb body weights (BW) and blood samples were collected weekly from days 0 to 28 and every 14 d until day 252 of age. Circulating leptin was measured in serum at days 0, 7, 14, 56, 210, and 252. An intravenous glucose tolerance test was performed at days 133 ± 0.28. At days 167 ± 0.33, individual daily intake was recorded over a 77-d feeding period to determine RFI. Rams were euthanized at days 285 ± 0.93, and body morphometrics, loin eye area (LEA), back fat thickness, and organ weights were collected and bone mineral density (BMD) and length were determined in the right hind leg. During gestation, OVER-F1 ewes tended to be 8.6% smaller than CON-F1 ewes (P  ≤ 0.06). F2 offspring were of similar BW from birth to day 70 (P  ≥ 0.20). However, from days 84 to 252, RES-F2 offspring tended to be 7.3% smaller than CON-F2 (P  ≤ 0.10). Granddam diet did not influence F2 ram body morphometrics, organ or muscle weights, LEA, adipose deposition, or leg BMD (P  ≥ 0.84). RES-F2 (−0.20) and CON-F2 (−0.45) rams tended to be more feed efficient than CON-F2 ewes (0.31; P  ≤ 0.08). No effects of granddam diet were observed on glucose or insulin average or baseline concentrations, area under the curve, first-phase response, or ratio (P  ≥ 0.52). However, CON-F2 rams (297 mg/dL ± 16.5) had a greater glucose peak compared with RES-F2 rams (239 mg/dL ± 11.2; P  = 0.05). Peak insulin concentrations were not influenced by granddam diet (P  = 0.75). At d 56, RES-F2 and OVER-F2 offspring had 53.5% and 61.8% less leptin compared with CON-F2 offspring, respectively (P  ≤ 0.02). These data indicate that poor maternal nutrition impacts offspring growth into the second generation with minimal impacts on offspring RFI, glucose tolerance, and circulating leptin. [ABSTRACT FROM AUTHOR]

Increased colostrum lactose concentration is also associated with greater colostrum yield and reduced protein and Brix% in dairy cattle ([83]), supporting the concept that colostrum yield may dilute component concentrations. Imposing mid to late-gestation nutrient restriction reduced first-milking colostrum yield (within 1 h postcalving) in beef cattle ([56]; [72]) without altering colostrum IgG concentration ([56]; [72]) but compromised total IgG yield ([72]). Colostrum IgG yield is often not reported in dairy and beef cattle, although one study noted that there was no difference in colostrum IgG output between treatments, despite colostrum IgG concentration being decreased ([84]). By contrast to cattle, colostrum yield in sheep appears more sensitive to protein supplementation during late gestation, with most studies indicating that increased protein intake (at times, in conjunction with greater RUP intake) increases colostrum yield ([38]; [3]). Keywords: cattle; colostrum; immunoglobulin G; prepartum; nutrition; sheep EN cattle colostrum immunoglobulin G prepartum nutrition sheep 24 36 13 06/20/23 20230601 NES 230601 Implications Many cattle and sheep do not produce enough colostrum for their offspring. [Extracted from the article]

To determine the effects of poor maternal nutrition on the growth and metabolism of offspring into maturity, multiparous Dorset ewes pregnant with twins (n = 46) were fed to either 100% (control; n = 13), 60% (restricted; n = 17), or 140% (over; n = 16) of National Research Council requirements from day 30 ± 0.02 of gestation until parturition. Offspring of these ewes are referred to as CON (n = 10 ewes; 12 rams), RES (n = 13 ewes; 21 rams), or OVER (n = 16 ewes; 13 rams), respectively. Lamb body weights (BW) and blood samples were collected weekly from birth (day 0) to day 28 and then every 14 d until day 252. Intravenous glucose tolerance test (infusion of 0.25 g dextrose/kg BW) was performed at day 133 ± 0.25. At day 167 ± 1.42, individual daily intake was recorded over a 77 d feeding period to determine residual feed intake (RFI). Rams were euthanized at day 282 ± 1.82 and body morphometrics, loin eye area (LEA), back fat thickness, and organ weights were collected. The right leg was collected from rams at necropsy and dual-energy x-ray absorptiometry was used to determine bone mineral density (BMD) and length. Averaged from day 0 until day 252, RES and OVER offspring weighed 10.8% and 6.8% less than CON offspring, respectively (P ≤ 0.02). When adjusted for BW, liver and testes weights tended to be increased and decreased, respectively, in RES rams compared with CON rams (P ≤ 0.08). Additionally, RES BMD and bone length were less than CON rams (P ≤ 0.06). Treatment did not influence muscle mass, LEA, or adipose deposition (P ≥ 0.41). Rams (−0.17) were more feed efficient than ewes (0.23; P < 0.01); however, no effect of maternal diet was observed (P ≥ 0.57). At 2 min post glucose infusion, glucose concentrations in OVER offspring were greater than CON and RES offspring (P = 0.04). Concentrations of insulin in CON rams tended to be greater than OVER and RES ewes at 5 min (P ≤ 0.07). No differences were detected in insulin:glucose or area under the curve (AUC) for glucose or insulin (P ≤ 0.29). Maternal diet did not impact offspring triglycerides or cholesterol (P ≤ 0.35). Pre-weaning leptin tended to be 70% greater in OVER offspring than CON (P ≤ 0.07). These data indicate that poor maternal nutrition impairs offspring growth throughout maturity but does not affect RFI. Changes in metabolic factors and glucose tolerance are minimal, highlighting the need to investigate other mechanisms that may contribute to negative impacts of poor maternal diet. [ABSTRACT FROM AUTHOR]

The effects of maternal nutrition on offspring wool production (quality and quantity) were evaluated. Primiparous Rambouillet ewes (n = 84) were randomly allocated to 1 of 6 treatments in a 2 × 3 factorial design. Selenium (Se) treatment (Adequate Se [ASe, 9.5 µg/kg BW] vs. High Se [HSe, 81.8 µg/kg BW]) was initiated at breeding, and maternal nutritional intake (control [CON, 100% of requirements] vs. restricted [RES, 60% of CON] vs. overfed [OVR; 140% of CON]) was initiated at d 50 of gestation. Lamb birth weight was recorded at delivery and all lambs were placed on the same diet immediately after birth to determine the effects of prenatal nutrition on postnatal wool production and follicle development. At 180 ± 2.2 d of age, lambs were necropsied and pelt weights were recorded. Wool samples were collected from the side and britch areas, while skin samples were collected from the side of each lamb only. While Se status did not influence side staple length in males, female lambs born from ewes on the ASe treatment had a shorter staple length (P < 0.05) when compared with females from ewes on the HSe treatment. Maternal nutritional intake and Se status did not influence (P = 0.23) wool characteristics on the britch. However, at the britch, female lambs had lower comfort factor (P = 0.01) and greater (P = 0.02) fiber diameter compared with male lambs. There was no effect (P > 0.13) of maternal Se supplementation, maternal nutritional plane, sex of the offspring, or their interactions for primary (29.10 ± 1.40 / 100 µm2), and secondary (529.84 ± 21.57 / 100 µm2) wool follicle numbers. Lambs from ASe ewes had greater (P = 0.03) secondary:primary wool follicle ratio compared with lambs from HSe ewes (20.93 vs. 18.01 ± 1.00). Despite similar postnatal diets, wool quality is affected by maternal Se status and maternal nutritional plane. [ABSTRACT FROM AUTHOR]

High preweaning mortality rates cost the Australian sheep industry an estimated $540 million annually in lost production, with losses significantly greater in twin (≥30%) compared with singleton lambs (≥10%). Previous intensive studies demonstrated that supplementing pregnant ewes with melatonin reduces adverse effects of fetal growth restriction and perinatal hypoxia on the neonatal brain via increased umbilical blood flow, placental efficiency, and antioxidant actions. The current study examined the effects of supplementing ewes with melatonin on the survival of twin Merino lambs under extensive grazing conditions. Pregnant mixed age ewes were implanted with 1 (M1, n = 50) or 2 (M2, n = 53) slow-release melatonin implants (18 mg, Regulin) at gestational days 70 to 90. Control ewes received no supplementation (CTL, n = 54). Ewes were monitored twice daily throughout the lambing period. Lamb survival, weight, and rectal temperature were recorded on the day of birth. Lamb blood samples were taken the following day for serum immunoglobulin G (IgG) analysis. Lamb survival and weight were recorded again at marking (30.6 ± 0.6 d postpartum) and weaning (70.7 ± 0.6 d postpartum). Lamb survival was increased in both melatonin treatments to 3 d postpartum (M1 = 98.0%; M2 = 95.3%; CTL = 83.3%; each P < 0.01), and this improvement was maintained to weaning (M1 = 94.0%; M2 = 92.5%; CTL = 79.6%; each P < 0.01). Melatonin did not affect lamb birthweight, rectal temperature, or growth rate. However, the rates of parturition-related death (dystocia, stillbirth, and birth injury) were greater in CTL lambs than M1 (P = 0.009) and M2 (P = 0.035). This suggests that improved survival is primarily due to melatonin-induced neuroprotection, although further studies are required to clarify the underlying mechanisms. These data provide evidence that supplementing pregnant twin-bearing Merino ewes with melatonin may be a practical strategy to reduce neonatal mortality and improve weaning rates in extensively managed sheep flocks. Although the present data are promising, this study is limited by small sample size and requires further replication. [ABSTRACT FROM AUTHOR]

Keywords: Sheep; mortality; morbidity; young lambs; colostrum; survey study EN Sheep mortality morbidity young lambs colostrum survey study INTRODUCTION One of the serious problems that affect the sheep industry in Kuwait is the high mortality rate of newborn lambs. In addition, lambs feeding on high quality colostrum helped these lambs to have more chances for survival, since colostrum is the only source for antibodies and nutrition for newborn lambs. Mastitis in ewes was reported to reduce serum Igs in ewes and consequently, in the colostrum (Chirstley et al., 2003; Lascelles, 1979); ewes in the present study were free of mastitis. [Extracted from the article]

Poor maternal nutrition during gestation can have immediate and life-long negative effects on offspring growth and health. In livestock, this leads to reduced product quality and increased costs of production. Based on previous evidence that both restricted- and overfeeding during gestation decrease offspring muscle growth and alter metabolism postnatally, we hypothesized that poor maternal nutrition during gestation would reduce the growth and development of offspring muscle prenatally, reduce the number of myogenic progenitor cells, and result in changes in the global expression of genes involved in prenatal muscle development and function. Ewes were fed a control (100% NRC)-, restricted (60% NRC)-, or overfed (140% NRC) diet beginning on day 30 of gestation until days 45, 90, and 135 of gestation or until parturition. At each time point fetuses and offspring (referred to as CON, RES, and OVER) were euthanized and longissimus dorsi (LM), semitendinosus (STN), and triceps brachii (TB) were collected at each time point for histological and RNA-Seq analysis. In fetuses and offspring, we did not observe an effect of diet on cross-sectional area (CSA), but CSA increased over time (P < 0.05). At day 90, RES and OVER had reduced secondary:primary muscle fiber ratios in LM (P < 0.05), but not in STN and TB. However, in STN and TB percent PAX7-positive cells were decreased compared with CON (P < 0.05). Maternal diet altered LM mRNA expression of 20 genes (7 genes downregulated in OVER and 2 downregulated in RES compared with CON; 5 downregulated in OVER compared with RES; false discovery rate (FDR)-adj. P < 0.05). A diet by time interaction was not observed for any genes in the RNA-Seq analysis; however, 2,205 genes were differentially expressed over time between days 90 and 135 and birth (FDR-adj. P < 0.05). Specifically, consistent with increased protein accretion, changes in muscle function, and increased metabolic activity during myogenesis, changes in genes involved in cell cycle, metabolic processes, and protein synthesis were observed during fetal myogenesis. In conclusion, poor maternal nutrition during gestation contributes to altered offspring muscle growth during early fetal development which persists throughout the fetal stage. Based on muscle-type-specific effects of maternal diet, it is important to evaluate more than one type of muscle to fully elucidate the effects of maternal diet on offspring muscle development. [ABSTRACT FROM AUTHOR]

Newly weaned, commercial Angus steers [body weight (BW) = 204 ± 19 kg; n = 24; 12 steers from dams administered an injectable trace mineral (MM ; Mulimin90) and 12 steers from control (CON) dams] were utilized to determine the effects of maternal supplementation with an injectable trace mineral on the inflammatory response of subsequent steers subjected to a lipopolysaccharide (LPS) challenge at the initiation of a 42-d receiving period. On day −2 steers were weaned, and the following day, shipped 354 km to the Beef Cattle and Sheep Field Laboratory in Urbana, IL. On day 0, steers were administered an intravenous LPS challenge. Body temperature and blood samples were collected from steers prior to LPS administration (0 h) and again at 0.5, 1, 2, 3, 4, 5, and 6 h. Blood samples were analyzed for trace mineral and cortisol at 0 and 2 h and glucose, insulin, LPS-binding protein (LBP), interleukin-1β (IL-1β), interleukin-6 (IL-6), haptoglobin, ceruloplasmin, and fibrinogen at 0, 0.5, 1, 2, 3, 4, 5, and 6 h. Calf BW was collected at trial initiation and subsequently every 14 d. Dry matter intake was collected daily and average daily gain (ADG) and feed efficiency were assessed. Initial plasma Zn tended (P = 0.06) to be greater for MM steers. However, there was no difference (P ≥ 0.31) in trace mineral status or serum cortisol at any other time. Total area under the curve (TAUC) for body temperature was lesser (P > 0.01) for MM steers. Basal LBP concentrations and TAUC for LBP tended (P ≤ 0.10) to be greater for MM steers. Peak concentration of IL-6 tended (P = 0.09) to be reached earlier for CON steers. However, there was no difference (P ≥ 0.11) in glucose, insulin, IL-6, ceruloplasmin, haptoglobin, and fibrinogen concentrations between treatments. Calf performance and feed efficiency did not differ (P ≥ 0.17) between treatments except ADG from day 28 to 42, which was greater (P = 0.03) for CON steers. Maternal supplementation with an injectable trace mineral tended to improve steer plasma Zn status at 0 h and tended to increase basal concentrations of LBP and overall LBP production when steers were administered an LPS challenge. Additionally, MM steers exhibited a more favorable change in body temperature following LPS administration. However, injectable trace mineral supplementation of dams during gestation had minimal to no effect on cytokine and acute-phase protein concentrations, as well as overall calf performance and efficiency during a 42-d receiving period. [ABSTRACT FROM AUTHOR]

Omega-3 long chain fatty acids have a positive impact on production. When consumed during late gestation, it might have fetal programming effects on the fetus, which will have lifelong impacts on development and production. The objectives of the present study were to evaluate the effect of increasing doses of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the diet of ewes in the last third of gestation on their body weight (BW), subcutaneous adipose tissue relative mRNA abundance of genes associated with adipose tissue metabolism, and growth performance and plasma metabolites and hormones of their offspring during the finishing phase. Ewes (n = 72) were blocked by BW and allotted to pens (8 per treatment) with 3 ewes per pen. Ewes were supplemented with an EPA and DHA source (Strata G113) at concentrations of 0, 1, or 2% of dry matter intake during the last 50 d of gestation. At lambing, all ewes were penned together and offered the same diet. After weaning at 60 d of age, lambs were blocked by BW and sex and fed for 56 d. All lambs were fed the same pellet diet (61.09% ground corn, 24.08% soy hulls, 11.09% soybean meal, 1.48% Ca salt of palm oil, and 2.26% mixed mineral vitamin), and were weighed every 14 d until the end of the trial. Blood samples were collected on the weight sampling days. Dry matter intake and refusals were weighed daily. Data were analyzed as a randomized complete block design with repeated measurements (SAS 9.4). Polynomial contrast (linear-L and quadratic-Q) was used for mean separation. There were no differences in ewe body condition score, milk production, milk fat, or milk protein, but there was a trend for increased (L, P = 0.06) lactose concentration, and also differences in DGAT1 (L, P = 0.04), Δ 5 -desaturase (Q, P = 0.06) and Δ 6 -desaturase (Q, P = 0.07), PPARα (Q, P = 0.03), ELOVL2 and 5 (Q, P < 0.07), FABP4 (Q, P = 0.04), FATP1 (Q, P = 0.06), leptin (Q, P = 0.02), and resistin (L, P = 0.05). Feeding pregnant ewes an increased amount of EPA and DHA in late gestation increased final BW (L, P = 0.01), ADG (L, P = 0.04; Q, P = 0.01), DMI (Q, P ≤ 0.01), plasma glucose concentration (L, P = 0.04), and trended to decrease ghrelin concentrations (L, P = 0.07) in offspring during the finishing period. Dam supplementation did not affect G:F, nor plasma NEFA concentration (P ≥ 0.53) of lambs. Therefore, increasing supplementation of EPA and DHA in pregnant ewes has an impact on offspring performance, increasing DMI, ADG, and BW. [ABSTRACT FROM AUTHOR]

Fetal hypoxia, resulting in oxidative stress in pregnancies, contributes to reduced fetal growth. Melatonin, a potent antioxidant, has been associated with improved oxidative status. Maternal oral melatonin supplementation in sheep from day 50 of gestation ameliorates the consequences of fetal growth restriction in sheep. In rats, melatonin supplementation increases fetal weight via improved placental efficiency and reduction of oxidative stress. The objective of this study was to evaluate whether melatonin supplementation of single (S)- or twin-bearing (T) ewes using either 0 (0MEL), 1 (18-mg MEL), or 2 (36-mg MEL) slow release 18-mg melatonin implants (Regulin) from 100 to 140 d of pregnancy (n = 8 per group) influenced fetal oxygen supply and fetal weight. Fetal umbilical vein blood samples were collected at P140 and partial pressure of oxygen (PO2) and hemoglobin saturation by oxygen (SatHb) measured. The placenta from each fetus was excised and placentomes individually weighed and typed (A–D). Pregnancy rank, sex of the fetus, number of implants, and their interaction on fetal weight, blood gases, and placentome weight were analyzed using ANOVA. A 22% and 14% increase (P < 0.05) in body weight was obtained in 36- and 18-mg MEL compared with 0 MEL twin male fetuses, respectively, but no treatment effects were observed in singletons or females from twin pregnancies. Fetuses from ewes receiving 36-mg MEL had an 18% to 20% increase in cord PO2 (P < 0.05) compared with 18-mg MEL and 0MEL fetuses, which in turn did not differ. Fetal weight was positively correlated with PO2 (r = 0.37; P = 0.02), SatHb (r = 0.26; P = 0.03), and O2 content (r = 0.236; P = 0.048). No treatment effect on placentome average weight, total placentome weight per fetus or per ewe, nor total number of placentomes per fetus was observed. However, placentae from 36-mg MEL fetuses had a greater proportion of Type C (P < 0.05) than 0MEL and 18-mg MEL ewes, and tended to have a lower proportion of Type A (P = 0.1) and a greater proportion of Type D (P = 0.06) placentomes, compared with 0MEL ewes. These results indicate that maternal melatonin implants, independently of sex, improve oxygen supply to the fetus, which could potentially improve lamb vigor at birth. In addition, melatonin can increase fetal weight of twin males, by improving placental adaptation and fetal blood oxygenation. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the effect of feeding an enriched diet with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) to finishing lambs born from ewes supplemented either with or without EPA and DHA during late gestation on productive performance, muscle fatty acid (FA), and hypothalamus mRNA concentration of metabolic genes and hormone receptors. Lambs born from dams fed during the last 50 d of gestation either with a control diet containing 0.39% Ca salts of palmitic fatty acid distillate (C) or Ca salts enriched with EPA and DHA (PFA) were used. After weaning lambs (n = 70) were blocked by weight (BW) and used in a 2 × 2 factorial into 2 finishing diets containing 1.5% of C or PFA. The 2 factors were the ewe diet and the finishing diet. Lambs (37.9 ± 0.4 kg) were weighed and blood sampled for glucose and NEFA measurements at days 1, 14, 28, and 42. Dry matter intake (DMI) was measured daily. At day 43, 14 females and 14 males were slaughtered, and hot carcass weight, body wall thickness, rib eye area, and FA composition of Longissumus thoracis muscle were evaluated. Female hypothalamuses were obtained and mRNA concentration of hormone receptors, neuropeptides, and their receptors was measured. Lambs born from PFA dams were heavier (P < 0.01). There was a time × finishing diet interaction for BW (P = 0.03), and lambs fed C had a greater BW. Lambs fed C had an increase in DMI (P < 0.01). There were no significant differences in plasma glucose and NEFA concentration (P > 0.1). Lambs born from PFA dams had a greater concentration of C22:0 (P < 0.03). Lambs fed C had higher concentrations of C18:1c15 (P < 0.01), C17:0 (P < 0.09), C18:0 (P < 0.09), and n6/n3 (P < 0.01). Lambs fed PFA had greater concentration (P < 0.05) of C16:1, C22:1, C20:5, C22:5, C22:6, total n3 FA, and total EPA and DHA. There was a significant dam × finishing diet interaction (P = 0.08) on mRNA concentration for MCR3, CCK-R, Cort-R, and CART. Lambs, which had the same treatment as their dams, showed lower overall mRNA concentration than those with different treatments between them and their dams. Lambs born from PFA ewes had lower concentration of MCR4 mRNA (P = 0.09) than C. Agouti-related peptides mRNA concentration was lower in lambs fed PFA (P = 0.06) than C. In conclusion, changes on lamb performance, muscle fatty acid composition, and metabolic neuropeptides depend not only on the lamb diet, but also on the dam diet during late gestation. [ABSTRACT FROM AUTHOR]

Chemokine (C-X-C motif) ligand 12 (CXCL12) and its receptor, chemokine (C-X-C motif) receptor 4 (CXCR4), are involved in significant biological processes associated with early pregnancy including increasing trophoblast invasion and stimulating placental vascularization. To further elucidate functions of CXCL12-CXCR4 signaling during early gestation, our objective was to inhibit CXCR4 in vivo using a CXCR4 antagonist, AMD3100. We hypothesized that inhibition of CXCR4 would negatively affect chemokine and angiogenic factor regulation imperative for placental development in sheep. Osmotic pumps containing PBS (control) or AMD3100 (CXCR4 antagonist) were surgically installed ipsilateral to the corpus luteum on d 12 of gestation and administered treatments directly into the uterine lumen. Maternal (caruncle and intercaruncle) and fetal membrane tissues were collected on d 23 of gestation and mRNA and protein expression were analyzed for vascular endothelial growth factor (VEGF), kinase insert domain receptor (KDR), fms related tyrosine kinase 1 (FLT1), fibroblast growth factor 2 (FGF2), angiopoietin 1 (ANGPT1), hypoxia inducible factor 1 a subunit (HIF1A), CXCL12, and its corresponding receptors (CXCR4 and CXCR7). Immunohistochemical procedures were performed for analysis of CXCL12 and cell proliferation. In caruncle tissue ipsilateral to the pump, mRNA for KDR, ANGPT1, HIF1A, and CXCL12 increased (P < 0.05) in treated ewes compared to control, whereas caruncle tissue contralateral to the pump had increased expression (P < 0.05) of KDR, and CXCL12 in treated ewes. In fetal membrane, CXCR4 mRNA and protein decreased (P < 0.05), while VEGF protein decreased (P < 0.05) in caruncle and fetal membrane tissue from treated ewes. Results from this study highlight the importance of CXCL12-CXCR4 signaling at the fetal-maternal interface. Inhibiting this axis may disrupt typical regulation of angiogenic factors needed for placental development and embryo growth. [ABSTRACT FROM AUTHOR]

The objectives of this study were 1) to compare the effects of a ME (AFRC, 1993) or a NE (Jarrige, 1989) system for rationing ewes during late gestation on ewe and progeny performance and 2) to investigate incremental increases in NE allocation above 100% of recommendation during late gestation on ewe and progeny performance. Fifty-two twin-bearing ewes (n = 13 per treatment) were rationed to either 100% of recommended ME requirements (100% ME) or 100, 110, or 120% of recommended NE requirements (100% NE, 110% NE, and 120% NE) from d 112 of gestation to parturition. Mean energy intake, measured as ME and NE, from Day 112 of gestation to parturition was higher in all NE treatments compared with 100% ME ewes (P = 0.01). Ewes offered the 3 NE treatments had a higher live weight at parturition compared with 100% ME ewes (P = 0.02), with 100% NE and 120% NE ewes still being heavier than 100% ME ewes at 35 d postpartum (P = 0.02). Increasing NE allowance resulted in a linear decrease in the level of BCS loss prepartum (P = 0.01) and a linear increase in the level of BCS loss postpartum (P = 0.01). There was no difference observed between any of the treatments in total colostrum produced to 18 h postpartum (P = 0.29) or in total colostrum intake to 18 h postpartum (P = 0.27). Increasing maternal NE allowance led to a linear increase in lamb serum IgG concentration at 24 h postpartum (P = 0.03). The estimated milk production of 120% NE ewes tended to be higher than all other treatments at wk 6 of lactation (P = 0.08). Colostral SFA levels from 100% ME ewes was lower than that of all 3 NE treatments (P = 0.01), and unsaturated fatty acid (UFA) levels in colostrum of the 100% ME ewes were lower than those of the 100% NE ewes (P = 0.01). Cumulative levels of milk SFA, UFA, and MUFA did not differ between treatments (P = 0.19). Lamb growth rates during the first 5 wk postpartum were unaffected by treatment (P = 0.18) as were days to slaughter (P = 0.34). It can be concluded that both ME and NE systems used in this study are appropriate for formulating ewe diets during late gestation. Increasing NE allocation above 100% altered the pattern of body reserve mobilization during late gestation and early lactation without observed variations in lamb performance during this time. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the effect of a high dietary Se supplementation on the whole transcriptome of sheep. A custom sheep whole-transcriptome microarray, with more than 23,000 unique transcripts, was designed and then used to pro- file the global gene expression of sheep after feeding a high dietary supplementation of organic Se. Lactating crossbred ewes (n = 10; 3 to 4 yr of age and 55 to 65 kg BW) at late lactation (100 ± 8 d in milk) were acclimated to indoor individual pen feeding of a basal control diet (0.40 mg Se/d, sodium selenite) for 4 wk. Sheep were then kept on a diet with an extra (high) supplementation of organic Se (1.45 mg Se/d as Sel-Plex; Alltech Biotechnology Pty Ltd, Dandenong, Victoria, Australia) for 40 d. Whole blood was collected at 2 time points (last day of the acclimatization period [T0] and after 40 d of the organic Se supplementation [T40]), and then total RNA was isolated and labeled for the subsequent microarray analysis. Significance Analysis of Microarrays, using the t-statistic, of the microarray data (T40 versus T0) evidenced the up- and downregulation of 942 and 244 transcripts (false discovery rate < 0.05), respectively. Seven genes showed the same trend of expression (up- or downregulation) when tested by quantitative real-time PCR (qPCR) in a cross-validation step. The microarray showed significant upregulation of the following selenoproteins at T40: selenium binding protein 1 (SELENBP1), selenoprotein W1 (SEPW1), glutathione peroxidase 3 (GPX3), and septin 8 (SEPT8). And the expression trends for SEPW1 and SEPT8 were validated using qPCR. Functional annotation of the differentially expressed genes showed the enrichment of several immune system--related biological processes (lymphocyte activation, cytokine binding, leukocyte activation, T cell differentiation, and B cell activation) and pathways (cytokine and interleukin signaling). Moreover, Gene Set Enrichment Analysis evidenced the enrichment of B and T cell receptors signaling pathways, with an enrichment score of 0.63 and 0.59, respectively. Overall, from a global gene expression (whole-transcriptome) point of view, shortterm supplementation of a high dietary organic Se to Se-nondeficient sheep results in a transcriptomic signature that mainly reflects an induced immune system and a modulation of transcription effect. Also, the present study provides a custom whole-transcriptome microarray platform that can be used in further global gene expression studies in the ovine species. [ABSTRACT FROM AUTHOR]

This study was conducted with an ovine intrauterine growth restriction (IUGR) model to test the hypothesis that dietary N-carbamylglutamate (NCG) and rumen-protected L-Arg (RP-Arg) supplementation are effective in ameliorating fetal growth restriction in undernourished ewes. Beginning on d 35 of gestation, ewes were fed a diet providing 100% of NRC-recommended nutrient requirements, 50% of NRC recommendations (50% NRC), 50% of NRC recommendations supplemented with 20 g/d RP-Arg (providing 10 g/d of Arg), and 50% of NRC recommendations supplemented with 5 g/d NCG product (providing 2.5 g/d of NCG). On d 110, maternal, fetal, and placental tissues and fluids were collected and weighed. Ewe weights were lower (P < 0.05) in nutrient-restricted ewes compared with adequately fed ewes. Maternal RP-Arg or NCG supplementation did not alter (P = 0.26) maternal BW in nutrient-restricted ewes. Weights of most fetal organs were increased (P < 0.05) in RP-Arg-treated and NCG-treated underfed ewes compared with 50% NRC-fed ewes. Supplementation of RP-Arg or NCG reduced (P < 0.05) concentrations of β-hydroxybutyrate, triglycerides, and ammonia in serum of underfed ewes but had no effect on concentrations of lactate and GH. Maternal RP-Arg or NCG supplementation markedly improved (P < 0.05) concentrations of AA (particularly arginine-family AA and branched-chain AA) and polyamines in maternal and fetal plasma and in fetal allantoic and amniotic fluids within nutrient-restricted ewes. These novel results indicate that dietary NCG and RP-Arg supplementation to underfed ewes ameliorated fetal growth restriction, at least in part, by increasing the availability of AA in the conceptus and provide support for its clinical use to ameliorate IUGR in humans and sheep industry production. [ABSTRACT FROM AUTHOR]

Poor maternal nutrition can affect the growth and development of offspring, which may lead to negative consequences in adult life. We hypothesized that lambs born to poorly nourished ewes would have reduced growth rate and increased fat deposition, with corresponding changes in the somatotropic axis, and leptin, insulin and glucose concentrations. Ewes (n = 36; 12/treatment) were assigned 1 of 3 diets; 100% (CON), 60% (RES), or 140% (OVER) of NRC requirements for TDN at d 31 of gestation until parturition. One lamb per ewe (n = 35; 11 to 12 per treatment) was used; 18 lambs were euthanized at d 1, and 17 were fed the same diet for 3 mo and then euthanized. Lamb crown rump length (CRL), heart girth, BW, and BCS were measured, and blood samples were collected at d 1 and then at weekly intervals until euthanasia. Averaged from d 1 until 3 mo, lambs from OVER ewes were larger compared with lambs born to CON ewes (BW [16.97 vs. 15.44 kg ± 0.60; P = 0.09], ADG [0.23 vs. 0.21 ± 0.01 kg/d; P = 0.01], and CRL [68.9 vs. 66.1 ± 0.80 cm; P = 0.02]). On a BW basis, heart weight from lambs from RES (0.18 kg ± 0.03; P = 0.03) ewes was greater than that of CON lambs (0.15 kg ± 0.03). Backfat thickness was reduced in RES lambs (0.11 ± 0.06; P ≤ 0.04) compared with CON (0.20 ± 0.06) and OVER (0.26 ± 0.06) lambs. Concentrations of IGF-I at 3 mo and IGFBP-3 from weaning (d 56 of age) to 3 mo of age tended to be greater (P ≤ 0.06) in OVER lambs (334 ± 66 ng/mL and 175 ± 11 arbitrary units [AU], respectively) than CON lambs (149 ± 66 ng/mL and 140 ± 11 AU, respectively). At 3 mo, leptin was greater in OVER lambs compared with RES lambs (1.24 vs. 0.78 ± 0.13 ng/mL; P < 0.05). Over time, average insulin concentrations were greater in OVER and RES lambs than CON lambs (0.49 and 0.49 vs. 0.33 ± 0.05 ng/mL; P ≤ 0.02). However, concentrations of GH, IGFBP-2, glucose, triglycerides, and total cholesterol were not different (P > 0.10) between treatment groups. During in vivo glucose tolerance test, baseline insulin concentrations were 68% and 85% greater (P = 0.01), respectively, in RES and OVER lambs compared with CON lambs. Similarly, the glucose:insulin ratio was greater in RES and OVER lambs compared with CON lambs (P = 0.01). Thus, in this experiment, poor maternal nutrition during gestation influenced body size, organ growth, fat accumulation, and concentrations of IGF-I, IGFBP-3, leptin, and insulin of offspring during the first 3 mo of age. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effects of offering Belclare X ewes a single diet rationed to 80, 100, or 120% of recommended ME requirements from d 119 of gestation to parturition, with concurrent changes in other dietary nutrients. The effects on the development of the fetus and subsequent offspring performance to weaning were monitored. Sixty twin-bearing ewes were allocated to 1 of 3 dietary treatments based on Agricultural and Food Research Council recommendations (AFRC, 1993) as amended by Robinson et al. (2002a) as follows: 80% of predicted ME requirement, 100% of predicted ME requirement, and 120% of predicted ME requirement. Ewes were individually fed for the final 4 wk of gestation. Diets fed were grass silage based; however, when silage intake failed to meet ME requirements, ewes were offered varying quantities of concentrates, on an individual basis, to ensure they met their required daily ME allocation. Concentrates offered were composed of 40% barley, 22% beet pulp nuts, 20% distillers' dried grains, and 14% soybean meal, on a DM basis. At birth, lambs were weighed, behavioral and skeletal measurements were recorded, and plasma blood samples were collected. At 1 h postpartum, a subset of lambs (n = 10) per treatment was euthanized to assess organ weight and intestinal morphology. At birth, there was no effect of treatment on lamb live weight at birth (P = 0.31), although lambs born to ewes offered 120% ME had a larger thoracic circumference (P = 0.05). Lambs born to ewes offered the excess energy treatment (120% ME) were quickest to stand and attempt to suckle after birth, in addition to having a greater live weight at weaning (P = 0.01) and ADG from birth to weaning (P = 0.05). Nutritional treatment had no effect on the organ weights (P ≥ 0.11) or the ileal morphology (P ≥ 0.62) of the lamb measured at 1 h postpartum. In summary, the impact of applying a dietary alteration to ewes in late gestation is not directly reflected in organ weight or total live weight at birth but is present at weaning, therefore outlining the poor reliability of using birth weight as an indicator of maternal nutrition during late gestation. [ABSTRACT FROM AUTHOR]

The present study was conducted to examine the effects of offering a single diet rationed to 80% (80% ME), 100% (100% ME), or 120% (120% ME) of recommended ME requirements from d 119 of gestation to lambing, with concurrent changes in other dietary nutrients. The effects on pre- and postpartum ewe performance, including estimated milk yield and milk fatty acid concentrations, were monitored. Sixty twin-bearing ewes were allocated to 1 of 3 dietary treatments (n = 20 per treatment) and individually fed for the final 4 wk of gestation. Metabolizable energy requirements were individually calculated for each ewe and amended according to treatment. Ewes were rationed daily on the basis of their treatment ME allocation, which led to concurrent alterations in other nutrient intakes. Diets were grass silage based and supplemented with concentrates to meet treatment ME allocation on an individual ewe basis. Ewes offered the 80% ME treatment had a lower liveweight (P = 0.04) and BCS (P = 0.03) at 24 h postpartum when compared with ewes offered the 120% ME diet. Although there was no difference in liveweight at either d 40 (P = 0.18) or 98 postpartum (P = 0.20), the difference in BCS persisted until d 40 postpartum (P = 0.02). Colostrum yield at 1 h postpartum (P = 0.03) and total yield up to 18 h postpartum (P = 0.04) was greater for ewes offered the 120% ME diet than either of the other treatment groups. Similarly, these ewes had a greater estimated milk yield during wk 3 of lactation (P = 0.04) and elevated concentrations of short-chain SFA (P = 0.02) and long-chain SFA (P ≤ 0.05) from wk 2 through 6 of lactation. In summary, the negative impact of applying a dietary insult to ewes in late gestation is reflected in colostrum and estimated milk yield and fatty acid composition, thus potentially influencing postpartum growth and development of the offspring. [ABSTRACT FROM AUTHOR]

Interspecies pregnancies between closely related species are usually performed in livestock to obtain improved and enriched offspring. Indeed, different hybrids have been obtained for research purposes since many years ago, and the maternal--fetal interactions have been studied as a possible strategy for species preservation. The aim of this study was to characterize by physiological and molecular approaches the interspecies pregnancy between bighorn sheep (Ovis canadensis mexicana) and domestic sheep (Ovis aries). Hybrids were obtained by artificial insemination; the blood pressure and protein urine levels were measured during the last two-thirds of gestation. After parturition, offspring and placentas were weighed and measured and cotyledons were counted and weighed and their surface area determined. Plasma samples were obtained between wk 8 and 21 of gestation to assess progesterone (P4), vascular endothelial growth factor (VEGF), and placental growth factor (PlGF) levels and cell-free RNA was isolated during the same period to assess hypoxia-inducible factor-1 α (HIF-1α) gene expression. Hybrid and normal pregnancies were analyzed using physiological and molecular parameters during the last two-thirds of gestation (wk 8--21). The results show that during the measurement period, ewes with a hybrid pregnancy presented normal blood pressure and no alteration in urinary protein content. However, compared with sheep with a normal pregnancy, those with a hybrid pregnancy had a decrease in fetal and placental growth as well as in the cotyledonary surface area. Furthermore, in the hybrid group, there was placental insufficiency, characterized by a decrease in P4 production, as well as indications of endothelial dysfunction, characterized an increase in plasma levels of VEGF and PlGF as well as in plasma gene expression of HIF-1α. Overall, the results indicate that hybrids of O. canadensis mexicana and O. aries presented intrauterine growth restriction, essentially due to altered endothelial function and chronic placental insufficiency. Further studies are necessary to overcome this primary placental dysfunction and thus obtain improved offspring for future molecular and genomic evaluations. [ABSTRACT FROM AUTHOR]

To determine the effect of undernutrition on embryo production and quality in superovulated sheep, 45 ewes were allocated into two groups to be fed diets that provided 1.5 (control, C; n = 20) or 0.5 (low nutrition, L; n = 25) times daily requirements for maintenance, from oestrous synchronization with intravaginal sponges to embryo collection. Embryos were collected 7 days after the onset of oestrus (day 0). Low nutrition resulted in lower live weight and body condition at embryo collection (P < 0.05). Diet (P < 0.01) and day of sampling (P < 0.001) significantly affected plasma non-esterified fatty acid (NEFA) and insulin concentrations. Plasma leptin concentrations decreased on day 7 only in L ewes. A significant effect of dietary treatment (P < 0.05) and day (P < 0.0001) was observed on plasma insulin-like growth factor (IGF)-I concentrations. The number of recovered oocytes and embryos did not differ between the groups (L: 15.4 ± 0.4; C: 12.4 ± 0.4). Recovery rate was lower (P < 0.05) in the L (60%) than in the C group (73%). The total number of embryos and number of viable-transferable embryos (5.0 ± 0.3 and 3.4 ± 0.3 embryos, respectively) of the L group were lower (P < 0.1) when compared with controls (8.4 ± 0.4 and 6.2 ± 0.4 embryos, respectively). Undernutrition during the period of superovulation and early embryonic development reduced total and viable number of embryos. These effects might be mediated by disruption of endocrine homeostasis, oviduct environment and/or oocyte quality. [ABSTRACT FROM PUBLISHER]

To determine how nutrient restriction and melatonin supplementation influence ewe and foetal hepatic and small intestinal energy use, 32 primiparous ewes on d 50 of gestation were fed 60% ( RES) or 100% ( ADQ) of NRC recommendations with 0 ( CON) or 5 mg/d ( MEL) of dietary melatonin. On d 130 of gestation, small intestine and liver were weighed and collected. Data were analysed as a completely randomized design with a 2 × 2 factorial arrangement of treatments. Liver weight (g/kg EBW) decreased (p = 0.02) in RES ewes. Jejunum weight (g/kg BW) increased (interaction p = 0.04) in ADQ- MEL ewes compared with all other treatments. Total in vitro O2 consumption (mol/min/tissue) and total citrate synthase activity (mol/min/tissue and mol/min/kg EBW) in liver decreased (p ≤ 0.03) in RES ewes. Oxygen consumption (mol/min/kg EBW) increased (interaction p = 0.02) in jejunum of ADQ- CON versus RES- MEL and ADQ- CON. Citrate synthase activity (mol/min/kg of EBW) increased (interaction p = 0.03) in jejunum of ADQ- MEL compared with RES- MEL and ADQ- CON. Foetal liver weight (g/kg BW) decreased (p = 0.02) in RES versus ADQ. Foetal small intestine weight (g/kg BW) decreased (interaction p = 0.05) in RES- MEL versus ADQ- MEL. Total O2 consumption (mol/min/tissue) and total citrate synthase activity (mol/min/kg of BW) in foetal liver decreased (p ≤ 0.05) in RES versus ADQ. Foetal small intestinal O2 consumption (mol/min/kg of BW) was greater (interaction p = 0.03) in RES- CON and ADQ- MEL than RES- MEL and ADQ- CON. Maternal nutrient restriction had a greater effect than melatonin supplementation on liver and jejunum mass and energy utilization in dams and foetuses. Because intestinal mass and energy utilization were more responsive to melatonin supplementation in ewes fed adequate nutrition compared with restricted ewes, melatonin may have limited use as a therapeutic supplement to help overcome potential negative effects of nutrient restriction. [ABSTRACT FROM AUTHOR]

Dietary melatonin supplementation during mid- to late-gestation increased umbilical artery blood flow and caused disproportionate fetal growth. This melatonin-induced increase in umbilical artery blood flow may alter nutrient availability to the fetus, which may lead to alterations in fetal size. The objectives of the current experiment were to determine amino acid (AA) and glucose concentrations as well as AA and glucose flux across the uteroplacenta using a mid- to late-gestation model of intrauterine growth restriction supplemented with dietary melatonin as a 2 × 2 factorial design. At day 50 of gestation, 32 ewes were supplemented with 5 mg of melatonin (MEL) or no melatonin (CON) and were allocated to receive 100% (adequate; ADQ) or 60% (restricted; RES) of nutrient requirements. On day 130 of gestation, uterine and umbilical blood flows were determined via Doppler ultrasonography during a non-survival surgery. Blood samples were collected under general anesthesia from the maternal saphenous artery, gravid uterine vein, umbilical artery, and umbilical vein for AA analysis and glucose. Total α-AA concentrations in maternal artery and gravid uterine vein were decreased (P < 0.05) in RES v. ADQ fed ewes. Maternal arterial − venous difference in total α-AA was increased (P ⩽ 0.01) in RES v. ADQ fed ewes, while total uterine α-AA flux was not different (P > 0.40) across all treatment groups. Fetal venous − arterial difference in total α-AA as well as uteroplacental flux of total α-AA were decreased (P < 0.05) in CON-RES v. CON-ADQ, and similar (P > 0.20) in MEL-RES v. CON-ADQ. Maternal concentrations and uterine flux of branched-chain AA (BCAA) were not different across all treatment groups; however, fetal uptake of BCAA was decreased (P < 0.05) in CON-RES v. CON-ADQ, and similar (P > 0.20) in MEL-RES v. CON-ADQ. Uterine uptake of glucose was not different (P ⩾ 0.08) across all treatment groups, while uteroplacental uptake of glucose was increased (P ⩽ 0.05) in RES v. ADQ ewes. In conclusion, maternal nutrient restriction increased maternal arterial − venous difference in total α-AA, while total uterine α-AA flux was unaffected by maternal nutrient restriction. Melatonin supplementation did not impact maternal serum concentrations or uterine flux of glucose or AA; however, melatonin did improve fetal BCAA uptake during maternal nutrient restriction. [ABSTRACT FROM PUBLISHER]

Newborn lambs depend on their dams for passive transfer of immunoglobulins, primarily IgG, for protection from harmful pathogens until their own immunological defenses have developed. Previous studies have suggested that supplementation with Se results in a modest increase in IgG concentration in serum of newborn calves and lambs. To evaluate the effect of the Se source and supplementation rate in ewes during pregnancy on passive transfer of IgG to their lambs, 210 Polypay, Suffolk, or Suffolk x Polypay cross ewes were divided into 7 treatment groups (n = 30 each) and drenched weekly with no Se, at the maximum FDA-allowed concentration with inorganic Na-selenite or organic Se-yeast (4.9 mg Se/wk), or with inorganic Na-selenite and organic Se-yeast at supranutritional concentrations (14.7 and 24.5 mg Se/wk). Ewe serum IgG concentrations were measured within 30 d of parturition, ewe colostrum and lamb serum IgG concentrations were measured at parturition before suckling, and lamb serum IgG concentrations were measured again at 48 h postnatal. Ewes receiving 24.5 mg Se/wk tended to have or had, independent of Se source, greater colostral IgG concentrations than ewes receiving4.9mg Se/wk overall (81.3 vs. 66.2 mg/mL; P= 0.08) and for Polypay ewes only (90.1 vs. 60.7 mg/mL; P = 0.03). Polypay ewes receiving Se-yeast at 24.5 mg Se/wk transferred a greater calculated total IgG amount to their lambs than Polypay ewes receiving Se-yeast at 4.9 mg Se/wk (15.5 vs. 11.6 g; P = 0.02), whereas the converse was true (interaction between Se source and dose concentration; P = 0.03) for Polypay ewes receiving inorganic Na-selenite at 24.5 mg Se/wk vs. Na-selenite at 4.9 mg/wk (11.6 vs. 15.7 g; P=0.08). Our results suggest that supranutritional Se supplementation of Polypay ewes during pregnancy increases colostral IgG concentrations but that the optimal supplementation rate for IgG transfer from ewe to lamb may differ for Na-selenite and Se-yeast. [ABSTRACT FROM AUTHOR]

Selenium is an essential micronutrient in sheep, and deficiency can limit lamb growth and survival. To evaluate how different chemical forms of Se administered to mature ewes at comparative dosages affect ewe and progeny performance, 240 ewes were divided into 8 treatment groups (n = 30 each) and drenched weekly with no Se; at the maximum FDA-allowed concentration with inorganic Na-selenite or organic Se-yeast (4.9 mg Se/wk); with inorganic Na-selenate (8.95 mg Se/wk); or with inorganic Na-selenite and organic Se-yeast at supranutritional concentrations (14.7 and 24.5 mg Se/wk, respectively). The treatment period started approximately 2 wk before breeding and lasted for 62.5 wk. Ewes of the no-Se and Se-yeast groups continued treatments for another 21 to 24 wk through a second lambing season. Chemical form or dosage of Se did not affect ewe reproductive performance based on proportion of ewes lambing in each treatment group, or number of lambs born, nursed, or weaned per ewe (all P > 0.10). Ewes receiving the highest supplementation rate of Se-yeast at 24.5 mg Se/wk had higher BCS (scale 1 to 5) at the end of yr 1 (2.95 vs. 2.66; P = 0.05) than ewes receiving Se-yeast at 4.9 mg Se/wk. Performance was better in lambs from ewes receiving Se-yeast at 24.5 mg Se/wk than in lambs from ewes receiving Se-yeast at 4.9 mg Se/wk or no Se. In yr 1, lambs from ewes receiving Se-yeast at 24.5 vs. 4.9 mg Se/wk were heavier at 120 d of age (37.0 vs. 34.2 kg; P = 0.05). In yr 2, lambs from ewes receiving Se-yeast at 24.5 mg Se/wk were or tended to be heavier at 60 d of age than lambs from ewes receiving no Se (21.2 vs. 19.0 kg; P = 0.04) or lambs from ewes receiving Se-yeast at 4.9 mg Se/wk (19.2 kg; P = 0.09). This effect was more pronounced in ewes raising multiple lambs. We conclude that supranutritional supplementation of ewes with Se-yeast at 24.5 mg Se/wk improves lamb growth and ewe health without negatively affecting reproductive performance. [ABSTRACT FROM AUTHOR]

The objective of this study was to evalu-ate the effects of overfeeding naturally-mated adoles-cent ewes (Ovis aries) on maternal, fetal, and postnatal lamb growth, hormone concentrations, and lamb car-cass characteristics. Two experiments were conducted in which singleton-bearing adolescent ewes were fed a diet containing 2.72 Mcal/kg ME at a rate which met NRC gestational age requirements (MN; n = 10 in Exp. 1, n = 7 in Exp. 2) or were fed the same diet ad libi-tum (15% refusal rate) throughout gestation (HN; n = 7 in Exp. 1, n = 6 in Exp. 2). Ewe BW was greater (P < 0.05) for HN than MN ewes beginning on 75 d and 52 d of gestation for Exp. I and 2, respectively. Final BCS was greater (P < 0.05) for HN than MN ewes in both experiments; 3.5 vs. 3.0, respectively, for Exp. 1, and 4.8 vs. 2.9, respectively, for Exp. 2. Fasting maternal blood insulin concentrations were greater (P < 0.05) in HN ewes near term (135 d of gestation), whereas fasting maternal glucose concentrations were greater (P < 0.05) during most of the second half of gestation in HN ewes, for both experiments. Gestation length did not differ (P = 0.69) between treatments in Exp. 1, but in Exp. 2, HN ewes had shorter (P = 0.01) gestation lengths (144 vs. 149 d) and had increased (P = 0.002) dystocia scores. Fetal abdominal circumference was greater (P < 0.05) in lambs from MN than HN ewes at 97 d of gestation in Exp. 1 (20.8 vs. 17.4 cm) but did not differ (P = 0.94) between treatments at 95 d of gestation in Exp. 2 (aver-aging 20.5 cm). There were no differences (P > 0.15) in lamb BW, abdominal circumference, crown-rump length, and biparietal distance at birth; or in postnatal BW and plasma concentrations of glucose, insulin, and lactate in either experiment. There were no differences (P > 0.18) in HCW, dressing percentage, LM area, fat thickness, or KPH between treatments in Exp. 2. Although there was no difference (P > 0.31) between treatments in concentrations of IGF1 or IGF2 mRNA in liver samples collected at harvest, lambs from MN ewes had greater (P < 0.05) concentrations of IGF1R and INSR mRNA, suggesting long-term effects of maternal diet on postnatal hepatic function. In conclusion, excess nutrition during gestation in naturally-mated adolescent ewes did not affect birth weight or postnatal perfor-mance of offspring. [ABSTRACT FROM AUTHOR]

Many areas of the western United States have soils that have increased Se content, and ruminants grazing these rangelands may ingest increased quantities of Se. In addition, high-energy diets or increased Se intake may induce gut inflammation. The objective of this study was to evaluate the effects of maternal plane of nutrition and increased dietary Se during gestation on inflammatory responses in neonatal lamb ileal tissue, a major immune organ. Rambouillet ewes (age = 240 ± 17 d; initial BW = 52.1 ± 6.2 kg) were allocated to 4 treatments arranged in a 2 x 2 factorial. Factors included Se [adequate Se (ASe, 11.5 μg/ kg of BW) or high Se (HSe, 77.0 μg/kg of BW)] initiated at breeding, and nutritional plane [100% (CON) or 140% (HIH) of requirements] initiated at d 40 of gestation. Ewes were fed individually from d 40, and lambs were removed at parturition and fed artificial colostrum and milk replacer. Lambs were necropsied at 20 d of age, and ileal tissues were sampled for immunoblotting and real-time quantitative reverse-transcription PCR analyses. The ASe-HIH and HSe-CON treatments had no effect (P = 0.179) on inflammatory signaling compared with ASe-CON. However, greater inflammatory signaling was detected in the HSe-HTH group, as shown by increased (P < 0.05) mRNA expression of tumor necrosis factor-α and chemotaxis IL-8. Consistently, phosphorylation of c-Jun N-terminal kiriase, a primary inflammatory signaling mediator, was greater (P < 0.05) in the HSe-HIH group compared with other treatments. Consistent with cytokine expression, mast cell density was less in the HSe-CON group than in other treatments. The expression of transforming growth factor 13 mRNA was greater (P < 0.05) in the HSe-HTH group; consistently, collagen content was increased in the HSe-HTH group compared with the ASe-CON group (P < 0.05). In conclusion, independently, neither HSe nor HIH had major effects on inflammation, but in combination, these maternal treatments induced an inflammatory response in the neonatal intestine. [ABSTRACT FROM AUTHOR]

This study was designed to characterize development of the ovine conceptus throughout gestation to establish the temporal relationships in metabolites, electrolytes, fluid volumes within the placenta, and hormonal changes with fetal growth. Length and weight of placentae, weight of cotyledons, and uterine weight increased between d 25 and 80 of gestation in advance of increases in fetal growth between d 80 and 140 of gestation. Allantoic fluid volumes changed (P < 0.01) between d 25 (21 mL) and 40 (91 mL), decreased to d 70 (32 mL), and then increased to d 140 (438 mL). Concentrations and total amounts of proteins in allantoic fluid were reduced between d 25 and 50, but total protein increased (P < 0.01) from d 40 (63 mg) to d 140 (2,991 mg). Concentrations of fructose in allantoic fluid varied between 2 and 6 mg/mL throughout gestation, but total fructose increased (P < 0.01) between d 25 (46 mg) and d 120 (679 mg). Concentrations of glucose ranged from 0.1 to 0.3 mg/mL, and total glucose increased (P < 0.05) from d 25 (3 mg) to d 140 (63 mg) of gestation. Amniotic fluid volume increased (P < 0.01) between d 30 and 140. Concentrations of estrogens in allantoic fluid, maternal uterine artery, and uterine vein increased (P < 0.01) with advancing pregnancy, and concentrations of progesterone in allantoic fluid (P <0.07) and plasma (P < 0.05) were affected by day of gestation. Concentrations of glucose were greater (P < 0.05) in uterine artery than uterine vein, but concentrations of electrolytes and osmolarity of plasma were not affected by day of gestation. Increases in weights of fetal organs were proportional to increases in fetal weight during gestation. Results of the present study of conceptus growth and development highlight areas of needed research and provide benchmarks for comparisons when evaluating effects of various treatments, environmental conditions, and epigenetics on successful outcomes of pregnancy in sheep. [ABSTRACT FROM AUTHOR]

Mature pregnant crossbred ewes (n = 90) were used in a randomized complete block design experiment and were assigned to 1 of 3 winter-feeding systems differing in primary feed source: haylage (HL), limit-fed corn (CN), or limit-fed dried distillers grains (DDGS). Effects of these winter-feeding strategies on postweaning progeny performance were determined. Lamb progeny (n = 96) were weaned at 61 ± 4 d of age and fed a common high-concentrate diet. Lambs were assigned to feedlot pen (n = 18) based on dam mid-gestation pen. Growth rate, DM1, and ADG were determined for the first 40 d of the finishing period. At 96 ± 4 d of age, 1 weather lamb was randomly selected from each pen (n = 18) for a glucose tolerance test. The experiment was terminated, and lambs were slaughtered individually when they were determined to have achieved 0.6-cm 12th-rib fat thickness. After a 24-h chill, carcass data were collected and a 2.54cm chop was removed from each lamb from the LM posterior to the 12th rib for ether extract analysis. Additional carcass measurements of bone, muscle, and fat from the shoulder, rack, loin, and leg were collected on 35 carcasses. At weaning, lamb BW was not different among treatments, whereas final BW tended to be greater (P = 0.09) for lambs from ewes fed DDGS and CN during gestation than from those fed HL. Overall lamb growth rate from birth to slaughter was not different among treatments. Lambs from ewes fed DDGS vs. CN or HL tended to have a greater initial insulin response (P = 0.09). Dressing percent was less (P 0.04) in lambs from ewes fed DDGS, but no difference (P = 0.16) was detected in HCW among treatments. As expected, 12th rib fat thickness was similar among treatments, whereas LM area was largest to smallest (P = 0.05) in lambs from ewes fed CN, HL, and DDGS, respectively. Proportion of internal fat tended to be greatest to smallest (P = 0.06) in lambs from ewes fed DDGS, CN, and HL, respectively. Calculated boneless trimmed retail cuts percentage was less (P = 0.04) in lambs from ewes fed DDGS than CN or ilL. Loin muscle weight as a percentage of wholesale cut tended (P = 0.10) to be greater in lambs from ewes fed CN and HL than, DDGS, whereas other muscle, bone, and fat weights and proportions were similar (P> 0.24) among treatments. Prepartum diet during mid to late gestation of ewes altered postnatal fat and muscle deposition and may be associated with alterations in insulin sensitivity of progeny. [ABSTRACT FROM AUTHOR]

Mature pregnant crossbred ewes (n = 90) were used in a randomized complete block design and assigned to 1 of 3 winter-feeding systems differing in primary feed source: haylage (HL), limit-fed corn (CN), or limit-fed dried distillers grains (DDGS). Effects of these winter-feeding strategies on ewe and lamb performance were determined. Diets were formulated to meet or exceed NRC (1985) nutrient requirements during gestation and were fed from about d 60 of gestation until parturition. All ewes were fed a common diet postpartum. Every 2 wk during gestation; BW and BCS were collected and diets were adjusted to maintain similar BW gain for ewes fed CN and DDGS vs. HL. At 80 and 122 d of gestation, jugular blood samples were collected at 0, 3, 6, and 9 h postfeeding to measure plasma glucose, insulin, NEFA, and blood urea nitrogen concentrations. At birth, 6 lambs per treatment were killed to measure body composition. At 28 ± 2 d postpartum, milk yield was measured. Lambs were weaned at 61 ± 4 d of age. During mid gestation (d 60 to 115), BW gain of ewes was similar among treatments; however, at d 115 of gestation ewes fed HL had a smaller (P = 0.04) BCS than ewes fed DDGS or CN. Plasma glucose concentrations were greater (P ≤ 0.004) in ewes fed CN than in those fed HL or DDGS just before feeding on d 80 and 122 of gestation, whereas ewes fed DDGS vs. CN or HL had greater (P ≤ 0.04) plasma insulin concentrations at 3 h postfeeding. At parturition, ewe BW was greatest for DDGS, least for HL, and intermediate for CN (P ≤ 0.003). Ewes fed CN and DDGS had greater BCS at parturition than those fed HL, but by weaning, ewes fed DDGS had greater BCS (P ≤ 0.05) than thdse fed CN or HL. Birth BW tended (P = 0.09) to be heavier for lambs from ewes fed CN and DDGS than from those fed HL prepartum, but there was no difference (P = 0.19) due to ewe gestation diet on lamb BW at weaning. At birth, lamb muscle, bone, organ, and fat measures were not affected (P > 0.13) by treatment. Ewe milk production and lamb preweaning ADG were also similar (P > 0.44) among treatments. Prepartum dam winter feed source did not have detrimental effects on pre- or postpartum ewe performance, but altered prepartum maternal nutrient supply during gestation, which affected birth weight but not preweaning growth or mortality. [ABSTRACT FROM AUTHOR]

Pregnant Targhee ewe lambs (n = 64; 50.7 ± 2.8 kg) were randomly allotted to one of eight treatments arranged in a 2 x 2 x 2 factorial design. Factors were Se level, early gestational nutrition, and late gestational nutrition. At breeding, ewes were assigned to two levels of Se supplementation, an adequate-Se (ASe; 8.5 μg Se/kg BW) or a high-Se (HSe; 85 μg Se/kg BW) diet, formulated using a Se-yeast product. Each diet was similar in CP (13.8%) and ME (2.66 Mcal/kg). Early nutritional treatments (initiated on d 50 of gestation) were control (early-C; fed to NRC recommendations) and restricted (early-R; fed 60% of controls). Late gestation nutritional treatments were the same (late-C vs. late-R) as used during early gestation, but were initiated on d 92. On d 132 of gestation, ewes were slaughtered and tissues harvested. Supplementation of Se increased (P < 0.01) Se concentration (ppm) of all maternal and fetal tissues tested. Selenium x late gestational nutrition interactive (P = 0.07) means for liver Se concentration were greater (P < 0.01) in ewes fed HSe-late-R compared with those fed HSe-late-C diets (14.7 vs. 9.8 ± 1.13 ppm). Nutrition restriction during both early (P = 0.09) and late (P = 0.01) gestation decreased total maternal kidney Se content (μg). Fetal heart Se concentrations (late nutrition x Se interaction; P = 0.03) were greatest in HSe-late-R (P < 0.01), intermediate in HSe-late-C (P < 0.01), and least (P < 0.01) in ASe-late-C and ASe-late-R fed ewes (1.79, 1.49, 0.35, and 0.33 ± 0.07 ppm, respectively). Fetal skeletal muscle Se concentrations were greater (P = 0.09) when ewes were early-R compared with early-C fed ewes. Dietary Se levels and maternal nutrient restriction alter maternal and fetal liver, kidney, and muscle, and fetal heart tissue Se concentrations. [ABSTRACT FROM AUTHOR]

Pregnant Targhee ewe lambs (n = 64; 50.7 ± 2.8 kg) were allotted randomly to one of eight treatments arranged in a 2 x 2 x 2 factorial design. Factors were Se level, early gestational nutrition, and late gestational nutrition. At breeding, ewes were assigned to two levels of Se supplementation, adequate-Se (ASe; 8.5 μg Se/kg BW) or a high-Se (HSe; 85 μg Se/kg BW) diet, formulated using a Se-yeast product. Each diet was similar in CP (13.8%) and ME (2.66 Mcal/kg). Early nutritional treatments (initiated on d 50 of gestation) were control (early-C; fed to NRC recommendations) and restricted (early-R; fed 60% of controls). Late gestation nutritional treatments were the same (late-C vs. late-R) as used during early gestation, but were initiated on d 92. On d 132 of gestation, ewes were slaughtered and tissues harvested. Level of Se had no affect (P = 0.51) on percentage of proliferating nuclei in jejunal tissue. Early and late nutrition interacted (P = 0.04) and resulted in ewes fed early-R-late-C diets having a greater (P = 0.09) proportion of crypt cell proliferating nuclei (11.59%) compared with early-C-late-C (8.44%) and early-R-late-R (8.90%) fed ewes. Ewes fed early-C-late-R diets had similar crypt cell proliferating nuclei (9.97%) compared with other treatments. Total jejunal proliferating cells were reduced (P = 0.02) in Se treated ewes and early x late nutrition interactions were present (P = 0.05). Ewes fed early-C-late-R diets had greater (P = 0.06) total jejunal cell proliferation when compared with early-C-late-C and early-R-late-R fed ewes. Ewes fed early-R-late-C diets had similar total jejunal cell proliferation compared with other treatments. Interestingly, total mucosal cell proliferation data were unaltered treatment. Treatments had no affect on percent jejunal vascularity (P = 0.80), capillary area (P = 0.65), or total microvascular volume (P = 0.61). [ABSTRACT FROM AUTHOR]

This study examined the hypothesis that responses of Scottish Blackface (BF, a hill breed) and Suffolk (SUF, a lowland breed) ewes to undernutrition between d 1 and 90 of pregnancy would differ. Over 2 consecutive breeding seasons, ewes (4 pens/treatment; 15 to 20 ewes/pen) were artificially inseminated and from d 1 to 90 after AT allocated to 0.75 (restricted; RES) or 1.0 (control; CON) energy requirements for ewe maintenance and fetal growth. From d 90 to term, all ewes were allocated feed to meet requirements for stage of pregnancy and expected litter size. On d 90, RES ewes had lighter BW (P = 0.001) and smaller BCS (P = 0.019) than CON ewes. Plasma NEFA concentrations were greater in RES than CON ewes (P 0.048) at d 60 of pregnancy. Pregnancy length was longer for RES than CON ewes (P 0.003). Lambs from SUFRES ewes had lighter birth weights than SUF-CON lambs, but BF-RES lamb birth weights were not different from BF-CON lambs (interaction, P = 0.066). However, maternal undernutrition did not affect BW at weaning (P > 0.45). Between birth and 3 d of age, BF lambs maintained greater body temperatures (P < 0.001) and plasma concentrations of triiodothyronine (T3, P < 0.001) and thyroxine (P < 0.001) than SUF lambs. Lambs from RES ewes had greater concentrations of T3 (P = 0.026) than CON lambs, whereas these differences were greater between BF-RES and BF-CON lambs than between SUF-RES and SUP-CON lambs (interaction, P = 0.028). Maternal undernutrition did not affect lamb rectal temperature (P > 0.27). In yr 1 only, fewer lambs (P = 0.022) were reared to weaning by RES than CON ewes. Similarly, in yr 1 only, other strongyle fecal egg counts at weaning were greater in SUF-RES lambs than SUF-CON, BF-CON, or BF-RES lambs (interaction, P = 0.099). This experiment showed that lambs of a breed selected for lean tissue growth and normally maintained in a lowland environment were more affected by maternal undernutrition between d 1 and 90 of pregnancy than lambs of a hill breed managed in a more adverse environment. [ABSTRACT FROM AUTHOR]

We evaluated the effects of preconception and gestational obesity in the ewe on offspring growth, metabolism, and glucose homeostasis. From 60 d before conception through parturition, multiparous ewes were fed 100% (control; n = 8) or 150% (obese, OB; n = 10) of NRC (1985) recommendations. Ewes on the OB diet increased BW by 30% from diet initiation to mating (P = 0.03) and by 52% by d 135 of gestation (P = 0.04), whereas control ewes increased BW by 7% (P = 0.65) from diet initiation to d 135 of gestation. Lambs were weaned at 120 d of age and were maintained as a group. At 19.5 + 0.5 mo of age, offspring from control and OB ewes were individually penned and subjected to a 12-wk ad libitum feeding challenge. At the beginning and end of the feeding challenge, dual x-ray absorptiometry was used to determine percentage of body fat, and a frequently sampled intravenous glucose tolerance test (FSIGT) with minimal model analysis was used to assess insulin and glucose homeostasis. At the beginning of the feeding challenge, BW and percentage of body fat were similar for control and OB offspring, averaging 69.0 ± 1.5 kg and 5.3 ± 0.5%, respectively. At the initial FSIGT, glucose effectiveness and insulin sensitivity were reduced (P < 0.05) in offspring from OB compared with control ewes. During the feeding challenge, plasma concentrations of leptin were increased (P < 0.05) in offspring from OB compared with control ewes. Fasted plasma glucose before the feeding challenge tended to be greater (P = 0.06) in the OB offspring compared with the control offspring (83.3 ± 1.4 vs. 79.0 ± 1.6 mg/dL, respectively). At the end of the feeding challenge, fasted plasma glucose and insulin were increased (P < 0.05) in the OB offspring compared with the control offspring (84.0 ± 1.4 vs. 79.5 + 1.5 mg/dL and 30.1 + 2.1 vs. 23.4 ± 2.2 μIU/mL, respectively). During the feeding challenge, offspring from OB ewes consumed approximately 10% more feed (P < 0.05) and tended to have increased BW gain (approximately 14%; P = 0.08) compared with offspring from control ewes. At the final dual x-ray absorptiometry scan, percentage of body fat was greater (P < 0.05) for offspring from OB ewes than for offspring from control ewes (16.5 ± 1.2 vs. 10.8 + 1.1%). At the final FSIGT, offspring from OB ewes had a decreased (P ≤ 0.05) acute insulin response to glucose, disposition index, and glucose effectiveness, and tended (P = 0.10) to have a decreased insulin sensitivity compared with offspring from control ewes. Maternal obesity induced before and during gestation leads to alterations in appetite, glucose and insulin regulation, and adiposity of mature offspring. [ABSTRACT FROM AUTHOR]

Primiparous ewes born as singletons to Rambouillet x Columbia crossbred ewes fed either 100% of NRC recommendations (control, Con; n 7) or 50% of NRC (nutrient restricted, NR; n = 7) from d 28 through 78 postmating were utilized for this study. At 1 yr of age, a subset of ewes born to Con (n = 4) and NR (n = 4) mothers received jugular catheters and were subjected to a corticotrophin–releasing hormone (CRH)/arginine vasopressin (AVP) challenge, an ACTH challenge, and an isolation stress test, in which ACTH and cortisol responses re determined. A week after these challenges, estrus was monitored twice daily in all ewes from Con (n = 7) and NR mothers (n = 7). Once estrus was observed (d 0), daily blood samples were collected from ewes for progesterone through the subsequent estrus. Estrous detection and daily blood sampling were repeated during an estrous cycle in the next year, ewes were hand mated at the second estrus, and pregnancy was determined by delivery of a live lamb(s). Ewes from NR mothers tended (P = 0.10) to have a greater peak ACTH response after an intravenous CRH/AVP injection than ewes from Con mothers. The cortisol response of ewes to a CRH/AVP or ACTH challenge was not influenced by maternal nutrition. In contrast, ewes from Con mothers tended (P = 0.10) to release more ACTH in response to the isolation stress test and showed a greater (P = 0.04) cortisol release than ewes from NR mothers. Ewes from NR mothers exhibited decreased (P < 0.05) plasma progesterone in both yr 1 and 2 of the study compared with ewes from Con mothers. Furthermore, fewer (P < 0.0001) ewes from NR mothers produced a lamb (1 of 7) than ewes from Con mothers (7 of 7) during yr 2 of the study. These findings indicate that maternal undernutrition during early gestation may affect stress responses by the offspring, but has limited impact on hypothalamopituitary–adrenal sensitivity. Furthermore, offspring of NR ewes exhibited reduced progesterone secretion during the luteal phase of their estrous cycles and a markedly reduced fertility compared with offspring from Con ewes. [ABSTRACT FROM AUTHOR]

To investigate the effects of nutritional plane and Se supply during gestation on ewe and off– spring performance and body composition, 84 Ram– bouillet ewe lambs (age = 240 + 17 d, BW = 52.1 + 6.2 kg) were allocated to a 2 x 3 x 2 factorial arrange– ment of treatments. Factors included Se [adequate Se (ASe, 11.5 pjg/kg of BW) or high Se (HSe, 77.0 ig/ kg of BW)] initiated at breeding, nutritional plane [60% (restricted, RES), 100% (control, CON), or 140% (high, HIH) of NRC requirements initiated at d 40 of gestation, and physiological stage at necropsy [3 to 24 h postpartum or d 20 of lactation]. Ewes were fed and housed individually in a temperature–controlled facility. At parturition, all lambs were removed and artificially reared until necropsy on d 20.6 ± 0.9 of age. Ewes assigned to the treatment at d 20 of lactation were transitioned to a common diet meeting lactation re– quirements and were mechanically milked. From d 95 of gestation through parturition and d 20 of lactation, ewe BW and BCS were least (P , 0.01) in the RES treat– ment, intermediate in the CON treatment, and greatest in the HIH treatment. Ewes fed HSe had a greater (P < 0.05) BCS increase than those fed ASe during mid– and late gestation. During gestation, ewes in the HIH treat– ment had the greatest (P , 0.001) ADG and G:F, those in the CON treatment were intermediate, and those in the RES treatment were least, whereas ewes fed HSe had greater (P , 0.001) ADG and G:F than those fed ASe during midgestation. Ewe backfat and LM area on d 135 of gestation were least (P , 0.001) in the RES treatment, intermediate in the CON treatment, and greatest in the HIH treatment, with ewes fed HSe having greater (P &#x00 0.03) backfat than those fed ASe. During the first 20 d of lactation, ewes fed the RES diet had greater (P , 0.09) G:F than those fed the CON and HIH diets. Physiological stage had no effect on ewe omental and mesenteric fat or perirenal fat weights, al– though both were greater (P , 0.001) for ewes fed the HIH diet than for those fed the RES and CON diets. At birth, lambs born to ewes in the RES group weighed less and had decreased curved crown rump lengths (P = 0.08) compared with those born to ewes in the CON and HIH groups, and lambs from ewes in the ASe–RES treatment were lighter (P , 0.08) than those from ewes in the HSe–RES, ASe–CON, and ASe–HIH treatments. Lambs from dams in the RES group had less (P < 0.05) BW from d 7 to 19 and decreased (P , 0.07) overall ADG compared with lambs from dams in the CON and HIH groups. Additionally, lambs from darns in the RES group had less (P < 0.08) perirenal fat than their counterparts, and lambs from dams in the HIH group had greater (P = 0.01) omental and mesenteric fat than lambs from dams in the RES group. Postpartum serum Se of ewes and lambs (birth and d 19) was increased (P , 0.001) by HSe feeding during gestation. Results indicate that BW differences in pregnant ewes attribut– able to nutritional plane are accompanied by changes in body composition and offspring BW, both of which may be affected by Se supply. [ABSTRACT FROM AUTHOR]

To determine the effects of maternal Se intake and plane of nutrition during midgestation, late gestation, or both on hormone and metabolite concentrations in the dam and on placental characteristics, pregnant ewe lambs (n = 64) were assigned to 1 of 8 treatments arranged in a 2 x 2 x 2 factorial array: Se level [initiated at breeding; adequate (3.05 μg/kg of BW) or high (70.4 μg/kg of BW)] and nutritional level [100% (control) or 60% (restricted) of NRC recommendations] fed at different times of gestation (d 50 to 90 (midgestation) or d 91 to 130 (late gestation)]. The control ewes had a greater (P = 0.01) percentage change in BW from d 50 than restricted ewes during both mid- and late gestation. Although blood urea N was not affected by either Se or nutritional level, restricted ewes had greater (P = 0.01) concentrations of circulating Se on d 66, 78, 106, 120, and 130 of gestation compared with control ewes. Both Se and timing of the nutritional level affected circulating progesterone; however, only nutritional level affected thyroxine and triiodothyronine concentrations in the dam. Nutrient restriction during late gestation decreased (P < 0.01) fetal BW and fetal fluid weight compared with the control ewes (3.75 vs. 4.13 + 0.10 kg and 1.61 vs. 2.11 ± 0.11 kg). Although neither Se nor nutritional level affected (P ⩽ 0.1) placental, caruncular, or cotyledonary weights, cotyledonary cellular proliferation was decreased (P < 0.05) in ewes receiving a high concentration of Se com- pared with those receiving adequate Se. In addition, either Se or nutritional level affected vascular endothelial growth factor (VEGFA), VEGFA-receptor 1, VEGFA- receptor 2, and NO synthase mRNA abundance in the cotyledonary tissue. In the caruncular tissue, either Se or nutritional level affected VEGFA-receptor 1, placental growth factor, and NO synthase mRNA abundance. Seldnium supplementation and the duration or timing of nutrient restriction appear to influence the endocrine and metabolic status of the ewe, which may influence nutrient transport and placental function. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different planes of nutrition in early pregnancy (EP) and mid-pregnancy (MP) of crossbred ewes on carcass characteristics of male offspring and reproductive performance of female offspring. During EP (d 1 to 39 after synchronized mating) ewes were allocated 60% (low, L-EP), 100% (medium, M-EP), or 200% (high, H-EP) of their energy requirements for maintenance. Between d 40 and 90 (MP), ewes were then allocated 80% (MMP) or 140% (H-MP) of their maintenance energy requirement. After d 90, all ewes were fed to fully meet energy requirements for late pregnancy. Male offspring (n = 83) were reared on a grass-based system and slaughtered at 42, 46, or 50 kg of BW. Female offspring (n = 60) were reared on a grass-based system, mated at 8 mo, and performance recorded until weaning of their first lamb crop. Concentrations of leptin, an adiposity indicator, in female offspring varied with the plane of maternal nutrition in early pregnancy. The L-EP offspring had greater leptin concentrations than H-EP offspring (P = 0.04), with M-EP offspring showing intermediate concentrations. Reproductive performance of female offspring was not affected by maternal plane of nutrition (P ⩾ 0.16). Female H-EP offspring gave birth to heavier lambs (generation 2 offspring) than M-EP (P = 0.006) with L-EP offspring intermediate. Male offspring of L-EP darns showed a trend toward poorer carcass conformation (P = 0.06) and increased fat classification (P = 0.07), consistent with increased fat depths over the loin (P = 0.02). There was a significant interaction between plane of nutrition in early pregnancy and mid-pregnancy for female offspring BW at 2 mo postmating and 16 wk postlambing (P ⩽ 0.04), and for male offspring perinephric and retroperitoneal fat and tissue depth (P ⩽ 0.02). For dams offered diet L-EP during early pregnancy, diet H-MP gave heavier offspring with more perinephric and retroperitoneal fat. In contrast, for dams offered diet H-EP during EP, diet M-MP gave offspring that were heavier or fatter or both. Maintenance level of nutrition in EP followed by M-MP or H-MP treatments resulted in offspring intermediate in fatness and BW. The data indicate that adaptations in EP and MP to compensate for nutritional deprivation or nutritional excess can alter the BW, adiposity, conformation, and leptin concentrations of offspring. Such changes have potential to alter health and lifetime productive performance. [ABSTRACT FROM AUTHOR]

Peripubertal ewe lambs (44.3 ± 1.1 kg of initial BW) were used in a 2 × 3 factorial design to test the effects of plane of nutrition (diet) and stage of gestation on maternal visceral tissue mass, intestinal cellularity, crypt cell proliferation, and jejunal mucosal vascularity. Singleton pregnancies to a single sire were established by embryo transfer, and thereafter ewes were offered a control (Control) or high (High) amount of a complete diet (2.84 Mcal/kg and 15.9% CP; DM basis) to promote slow or rapid maternal growth rates. After d 90 of gestation, feed intake of the Control group was adjusted weekly to maintain BCS and meet the increasing nutrient demands of the gravid uterus. Ewes were slaughtered at 50 d (n = 6 Control; n = 5 High), 90 d (n = 8 Control; n = 6 High), or 130 d (n = 8 Control; n = 6 High) of gestation. Ewes were eviscerated and masses of individual organs were recorded. The jejunum was sampled and processed for subsequent analyses. Final ewe BW for Control-fed ewes was similar at d 50 and 90 and increased (P = 0.10) from d 90 to 130 (46.0, 48.9, and 58.2 ± 1.6 kg, respectively), whereas final BW increased (P ≤ 0.01) throughout gestation in High-fed ewes (58.3, 68.8, and 81.1 ± 1.6 kg, respectively). Relative jejunum mass (g/kg of maternal BW) was greater (P = 0.003) in Control-fed ewes compared with High-fed ewes and tended (P = 0.11) to decrease from d 50 to 130. There were diet × stage of gestation interactions (P ≤ 0.08) for ileum and small intestinal total and relative weights. Ileum mass (g/kg of maternal BW) in Control-fed ewes was less (P = 0.07) compared with High-fed ewes at d 50, was equal (P = 0.19) to High-fed ewes at d 90, and was greater (P = 0.02) than High-fed ewes at d 130. Small intestine mass (g/kg of maternal BW) was similar between Control- and High-fed ewes at d 50 and 90, but Control-fed ewes had greater (P = 0.01) mass at d 130. Jejunal RNA and protein concentrations were less (P ≤ 0.07) and DNA was unaffected (P = 0.43) in Control-fed compared with High-fed ewes. Stage of gestation did not affect jejunal RNA, DNA (mg/g), or protein concentrations. Jejunal cellular proliferation was not affected by diet or stage of gestation. In jejunal mucosal tissue, capillary number decreased, whereas capillary surface density and area per capillary increased (P = 0.01) with advancing pregnancy (d 50 vs. d 130), but were independent of diet. Data indicated that intestinal mass as a proportion of maternal BW declined in overnourished, gestating ewe lambs. This response was more pronounced during late gestation and is likely explained by the increasing maternal BW and adiposity rather than by the changing cellularity or cell proliferation. [ABSTRACT FROM AUTHOR]

Pregnant Targhee ewe lambs (n = 32; BW = 45.6 ± 2.2 kg) were allotted randomly to 1 of 4 treatments in a completely randomized design to examine the effects of level and source of dietary Se on maternal and fetal visceral organ mass, cellularity estimates, and maternal jejunal crypt cell proliferation and vascularity. Diets contained (DM basis) either no added Se (control) or supranutritional Se from high-Se wheat at 3.0 ppm Se (SW) or from sodium selenate at 3 (S3) or 15 (S15) ppm Se. Diets were similar in CP (15.5%) and ME (2.68 Mcal/kg of DM) and were fed to meet or exceed requirements. Treatments were initiated at 50 ± 5 d of gestation. The control, SW, S3, and S15 treatment diets provided 2.5, 75, 75, and 375 jig of Se/kg of BW, respectively. On d 134 ± 10 of gestation, ewes were necropsied, and tissues were harvested. Contrasts, including control vs. Se treatments (SW, S3, and S15), SW vs. S3, and S3 vs. S15, were used to evaluate differences among Se levels and sources. There were no differences in ewe initial and final BW. Full viscera and liver mass (g/kg of empty BW and g/kg of maternal BW) and maternal liver protein concentration (mg/g) and content (g) were greater (P < 0.04) in Se-treated compared with control ewes. Maternal liver protein concentration was greater (P = 0.01) in SW vs. S3 ewes, and content was greater (P = 0.01) in S15 compared with S3 ewes. Maternal jejunal mucosal DNA concentration (mg/g) was greater (P = 0.08) in SW compared with S3 ewes. Total number of proliferating cells in maternal jejunal mucosa was greater (P = 0.02) in Se-fed compared with control ewes. Capillary number density within maternal jejunal tissue was greater (P = 0.08) in S3 compared with SW ewes. Selenium treatment resulted in reduced fetal heart girth (P = 0.08). Fetal kidney RNA (P = 0.04) and protein concentrations (mg/g; P = 0.03) were greater in Se-treated compared with control ewes. These results indicate that supranutritional dietary Se increases cell numbers in maternal jejunal mucosa through increased crypt cell proliferation. No indications of toxicity were observed in any of the Se treatments. [ABSTRACT FROM AUTHOR]

The article presents abstracts on animal physiology topics which include the reproductive performance of heifers offered ad libitum or restricted access to feed for a particular period after weaning, effects of fetal and uterine genotype on placentome morphology in sheep, and effects of maternal dietary restriction and selenium intake on placentome development and cell proliferation in ewes.

The article presents abstracts on animal physiology topics which include the effects of nutrition on oocyte quality and early embryonic development in sheep, somatic cell nuclear transfer in cattle, and characterization of messenger RNA expression for the endothelial differentiation of G-protein-coupled receptors in porcine endometrial tissue during the pre-implantation period of pregnancy.

The article presents abstracts related to sheep production and management. They include "Effect of dried distillers grains substituting for soybean meal on growth and feed intake of Pelibuey sheep," "Sheep mastitis: Pathogens and susceptibility to antimicrobial agents," and "Genetic resistance to nematode parasites in sheep: Use of Box-Cox transformation in QTL mapping."

This study utilized maternal undernutrition from early to midgestation in the ewe to determine the impact(s) of intrauterine growth restriction on postpartum growth of male offspring and the potential mechanisms involved. Multiparous ewes were fed 50% (nutrient-restricted) or 100% (control-fed) of their nutrient requirements (NRC, 1985) between d 28 and 78 of gestation, and then all ewes were fed 100% of the NRC requirements from d 79 through lambing. Male lambs born to nutrient-restricted (n = 9) and control-fed (n = 9) ewes exhibited similar BW (5.8 vs. 6.0 ± 0.3 kg) and crown-rump lengths (53.8 vs. 55.4 ± 1.0 cm) at birth. At 63 and 250 d of postnatal age, weather lambs were subjected to a glucose tolerance test, in which a bolus of glucose was administered i.v. to evaluate changes in glucose and insulin concentrations. After i.v. glucose administration at 63 d of age, lambs from nutrient- restricted ewes exhibited a greater area under the curve for glucose (AUCg; 6,281 vs. 5,242 ± 429; P < 0.05) and insulin (AUCi; 21.0 vs. 8.6 ± 1.9; P < 0.001) than lambs from control-fed ewes. After glucose administration at 250 d of age, lambs from nutrient-restricted ewes had greater AUCg (7,147 vs. 5,823 ± 361; P < 0.01) but a lower AUCi (6.4 vs. 10.2 ± 1.9; P = 0.05) than lambs from control-fed ewes. Lambs from nutrient-restricted ewes were heavier (26.6 vs. 21.8 ± 2.3 kg; P < 0.05) and had more backfat (0.30 vs. 0.21 ± 0.03 cm, P < 0.05) by 4 mo of age than the lambs from control-fed ewes. At slaughter at 280 d of age, lambs from nutrient-restricted ewes remained heavier than lambs from control-fed ewes, had greater (P < 0.05) amounts of kidney and pelvic-area adipose tissue, and tended (P < 0.10) to have reduced LM and semitendinosus muscle weights as a percentage of HCW. These data demonstrate that a bout of maternal undernutrition during early to midgestation in sheep increased BW and fat deposition during adolescence and dysregulated glucose uptake in the absence of any change in birth weight. [ABSTRACT FROM AUTHOR]

Embryonic and fetal mortality reduce lambing rates and litter sizes, thus contributing to economic losses in the sheep industry. In the current study, the timing of late embryonic and fetal loss in ewes and the factors with which these losses were associated were examined. Ewes lambing and lambs born were compared with pregnancy diagnosis and counts of embryos by ultrasonography near d 25, 45, 65, or 85 of gestation. Approximately 19.9% of the ewes experienced late embryonic loss, fetal loss, or both; and 21.2% of the embryos or fetuses were lost from d 25 to term. Potential offspring were lost throughout gestation; 3.7% of embryos from d 25 to 45, 4.3% of fetuses from d 45 to 65, 3.3% from d 65 to 85, and 11.5% from d 85 to parturition; thus, approximately 3 to 4% of the potential offspring were lost for each 20-d period of pregnancy beyond d 25. A greater proportion of ewes lost one (36.7%) rather than all (20.5% single; 3.8% multiple) embryos or fetuses. The patterns of loss were similar in ewes mated during the anestrous season and the transitional period and did not vary with service period within breeding season or method of synchronization of estrus. Late embryonic or fetal losses were not related to the temperature-humidity index. Maternal serum collected near d 25, 45, 65, or 85 of gestation was assayed for concentrations of progesterone, estradiol-17β, and vascular endothelial growth factor (VEGF). The proportions of embryos or fetuses lost were associated with breed type (P < 0.05), as were concentrations of progesterone (P < 0.01), estradiol (P < 0.05), and VEGF (P < 0.01). The relationships of loss or retention of pregnancy to hormonal variables at the 4 stages studied were limited. Complete and partial losses increased rapidly as maternal progesterone at d 25 decreased below 2 ng/mL (P < 0.05). Survival of fetuses within a litter from d 25 to 65 was greater for ewes with medium concentrations of VEGF near d 25 and from d 65 to parturition was greater for ewes with high concentrations of VEGF near d 45 (P < 0.05). In summary, late embryonic or fetal losses occurred from d 25 throughout gestation and varied with breed type and with concentrations of progesterone in maternal serum on d 25. [ABSTRACT FROM AUTHOR]

Maternal nutrient restriction from early to midgestation can lead to fetal growth retardation, with long-term impacts on offspring growth, physiology, and metabolism. We hypothesized that ewes from flocks managed under markedly different environmental conditions and levels of nutrition might differ in their ability to protect their own fetus from a bout of maternal nutrient restriction. We utilized multiparous ewes of similar breeding, age, and parity from 2 flocks managed as 1) ewes adapted to a nomadic existence and year-long, limited nutrition near Baggs, WY (Baggs ewes), and 2) University of Wyoming ewes with a sedentary lifestyle and continuous provision of more than adequate nutrition (UW ewes). Groups of Baggs ewes and UW ewes were fed 50 (nutrient restricted) or 100% (control fed) of National Research Council recommendations from d 28 to 78 of gestation, then necropsied, and fetal and placental data were obtained. Although there was a marked decrease (P < 0.05) in fetal weight and blood glucose concentrations in nutrient-restricted vs. control fed UW ewes, there was no difference in these fetal measurements between nutrient-restricted and control-fed Baggs ewes. Nutrient-restricted and control-fed UW ewes exhibited predominantly type A placentomes on d 78, but there were fewer (P < 0.05) type A and greater (P < 0.05) numbers of type B, C, and D placentomes in nutrient-restricted than control-fed Baggs ewes. Placental efficiency (fetal weight/placentomal weight) was reduced (P = 0.04) in d 78 nutrient-restricted UW ewes when compared with control-fed UW ewes. In contrast, nutrient-restricted and control-fed Baggs ewes exhibited similar placental efficiencies on d 78. This is the first report of different placental responses to a nutritional challenge during pregnancy when ewes were selected under different management systems. These data are consistent with the concept that Baggs ewes or their conceptuses, which were adapted to both harsh environments and limited nutrition, initiated conversion of type A placentomes to other placentomal types when subjected to an early to mid-gestational nutrient restriction, whereas this conversion failed to occur in UW ewes. This early placentomal conversion in the Baggs ewes may function to maintain normal nutrient delivery to their developing fetuses during maternal nutrient restriction. [ABSTRACT FROM AUTHOR]

Nutrition has been shown to influence several reproductive functions, including hormone production, oocyte competence and fertilization, and early embryonic development. To determine the effects of maternal diet on in vitro fertilization (IVF) and early embryonic development, ewes (n = 18; 47.0 ± 1.5 kg of initial BW) were divided into control and underfed (60% of control) nutritional planes for 8 wk before oocyte collection. Pelleted diets containing 2.4 Mcal of ME/kg and 13% CP (DM basis) were fed once daily. During the first 4-wk acclimation phase, control and underfed ewes were fed 1,000 and 600 g/d, respectively. From wk 4 to 8, control (adequate) ewes were fed to maintain BW and offered 720 g/d, whereas underfed ewes received 432 g/d (60% restricted). Synchronization of estrus was performed using progestagen sponges for 14 d. Follicular development was induced by twice daily injections of FSH on d 13 (5 units/injection) and 14 (4 units/injection) of the estrous cycle. Oocytes were collected from all visible follicles on d 15 of the estrous cycle. After IVF, the proportion of developing embryos was evaluated throughout an 8-d culture period. Undernutrition decreased (P < 0.006) the rate of cleavage, number of blastocysts per ewe, and rate of blastocyst formation (from 79 to 64%; from 3.3 to 0.8; and from 31 to 8%, respectively). However, the number of visible follicles, total number of oocytes, number of healthy oocytes, percentage of healthy oocytes, number of cleaved oocytes, and morula formation per ewe were similar for control and underfed ewes. These data indicate that undernutrition of donor ewes, resulting in lower BW and BCS, has a negative effect on oocyte quality, which results in lower rates of cleavage and blastocyst formation. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) production has been shown to increase uterine blood flow and be elevated in ewes carrying multiple fetuses during late gestation. Vascular endothelial growth factor (VEGF) has been reported to increase eNOS expression and NO production in endothelial cell cultures. As angiogenesis and vasodilatation of the uterine and placental vascular beds are important at all stages of pregnancy, it is important to understand how VEGF and NO change throughout gestation in circulation. Therefore the objectives of the current study were to evaluate the systemic levels of VEGF and NO metabolite (NOx) throughout ovine gestation and to determine if there was an effect of sheep carrying singletons versus multiple fetuses. NOx and VEGF concentrations were analysed in systemic blood from pregnant ewes starting on day 27 of pregnancy and at multiple intermittent intervals throughout pregnancy until term. Blood samples from non-pregnant and postpartum ewes were also analysed. NOx concentrations in maternal blood expressed a biphasic pattern with NOx concentrations increasing ( P< 0.05) over non-pregnant values on days 40–69 of gestation, returning to non-pregnant concentrations from days 70–100, and again increasing ( P< 0.05) until term. Postpartum NOx concentrations were similar to non-pregnant values. While ewes carrying multiple fetuses had increased ( P< 0.05) concentrations of NOx on days 60–69, there were no differences in NOx concentrations in ewes carrying singletons or multiples from day 70–99 of gestation. Starting on day 100 and continuing throughout the duration of pregnancy, ewes carrying multiple fetuses had increased ( P< 0.05) concentrations of NOx compared to ewes carrying singletons. Concentrations of VEGF showed a different pattern from NOx with VEGF decreasing ( P< 0.05) from day 20–69 of pregnancy compared to non-pregnant ewes. Concentrations of VEGF returned to non-pregnant levels by day 70 and remained constant throughout the duration of pregnancy. On days 20–39, ewes carrying singleton fetuses had an increased VEGF concentration ( P< 0.05), whereas ewes carrying multiple fetuses demonstrated elevated VEGF concentrations from day 90–109 of gestation. Concentrations from non-pregnant and postpartum ewes did not differ ( P> 0.1). While there was no effect of fetal number on circulating VEGF concentrations, circulating levels of NOx were substantially increased ( P< 0.05) in ewes carrying multiple fetuses, compared to ewes carrying singletons. The pattern of the rise in NOx in circulating plasma was not directly associated with changes in VEGF regardless of the number of fetuses present. However, circulating concentrations of NOx and VEGF appear to, respectively, follow patterns of uterine blood flow and angiogenesis of the uterus. An understanding of these circulatory patterns may have important implications for fetal size, birth weight and fetal/developmental origins of adult disease. [ABSTRACT FROM AUTHOR]