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The use of antimicrobial drugs and coccidiostats in poultry farming is widespread, with a significant proportion of these drugs being excreted and released into the environment. The residues of such drugs in poultry litter (PL) can result in the development of antibiotic-resistant bacteria. The impact of different biotic treatments (aerobic, anaerobic, and stacking) on broiler litter (BL) before its use as animal feed has not been studied extensively, nor have the differences between antimicrobial-dependent and independent broiler farms been investigated. This study aimed to determine the resistant bacteria in BL used as ruminant feed before and after litter treatment. The results show that the most resistant bacteria before BL treatment were the Enterococcus species. This study also found that the quantity of amoxicillin-resistant Enterococcus detected in samples from antimicrobial-dependent farms was significantly higher than in those from antimicrobial-independent farms. Additionally, 14% of bacteria were multi-resistant to tetracycline, sulfafurazole, and erythromycin in antimicrobial-independent farm litters, significantly lower than those measured in antimicrobial-dependent broiler farm litter. This study highlights the importance of better understanding, regulating, managing, and using animal waste appropriately to reduce the number of antibiotic-resistant bacteria and minimize the use of antimicrobials that carry high risks for animals, humans, and the environment

The aim of this study was to reduce voluntary dry matter intake (DMI) to increase feeding efficiency of preclassified inefficient (INE) dairy cows through restricted feeding. We studied the effects of dietary restriction on eating behavior, milk and energy-corrected milk (ECM) production, in vivo digestibility, energy balance, and measures of feed efficiency [residual feed intake (RFI) and ECM/DMI]. Before the experiment, 12 pairs of cows were classified as INE. The 2 dietary treatments consisted of ad libitum feeding versus restricted feeding of the same total mixed ration containing 36.5% roughage. Inefficient cows fed the restricted total mixed ration had a shorter eating time and lower meal and visit frequency, but a similar rate of eating, meal size, and meal duration compared with INE cows fed ad libitum. Compared with the INE cows fed ad libitum, restricted INE cows had 12.8% lower intake, their dry matter and neutral detergent fiber digestibility remained similar, and their ECM yield was 5.3% lower. Feed efficiency, measured as RFI, ECM/DMI, and net energy retained divided by digestible energy intake, was improved in the restricted INE cows as compared with the ad libitum cows. Our results show that moderate DMI restriction has the potential to improve feed efficiency of preclassified INE cows.

Feed is usually the costliest input in lactating cow's farms. Therefore, the developing of methods for a better adjustment of feed intake to cow's energetic needs in order to improve efficiency is desired. The aim of this study was to improve feed efficiency of low-efficient (LE) cows through a moderate increase in diet forage-to-concentrate ratio. We studied the effects of replacing 8.2% corn grains in a control low-fiber (LF) diet that contained 17.5% forage neutral detergent fiber (NDF) with 7.5% wheat straw + 0.7% soybean meal for a high-fiber (HF) diet that contained 23.4% forage NDF. Based on efficiency data of individual cows from the Agricultural Research Organization's herd measured in our previous study, 15 pairs of pre-classified LE multiparous mid-lactating Israeli Holstein dairy cows were selected, each pair with similar performance, intake, and efficiency data; each member of a pair was then adapted for 2 weeks to one or the other dietary treatment. Traits examined during the 5 weeks of the experiment were DM intake (DMI), eating behavior, milk production, in vivo digestibility, and estimation of feed efficiency [energy-corrected milk (ECM)/DMI and energy balance]. Cows fed the HF diet showed slower eating rate, smaller visit and meal sizes, longer daily eating time, higher visit frequency, and longer meal duration, compared to those fed the LF diet. The DMI of cows fed the HF diet was 9.1% lower, their DM digestibility decreased from 65.7 to 62.2%, and their ECM yield was 7.0% lower than in cows fed the LF diet. Feed efficiency, measured as net energy captured/digestible energy intake, improved in the cows fed the HF vs. LF diet while feed efficiency measured as ECM/DMI remained similar. Our results thus show the potential of improving feed efficiency for milk production in LE cows by increasing the forage-to-concentrate ratio.

This study aimed to identify individual characteristics differing among high-efficiency (HEf; upper 20%, n = 31), low-efficiency (LEf; lower 20%, n = 31), and mid-efficiency (MEf, 60% n = 93) lactating cows. Primiparous (37) and multiparous (118) high-producing milking cows at 30 to 180 d in milk were fed individually a low-roughage diet [31.6% of dry matter (DM)] for 4 wk. Daily average DM intake, rate of eating, visit duration, meal size, and daily rumination time were higher in LEf compared with HEf cows. On the other hand, HEf cows exhibited higher digestibility of DM, crude protein, and neutral detergent fiber than the LEf cows. Daily eating time was similar in the HEf and LEf groups and higher than that of the MEf cows. Visit and meal frequency, average visit and meal duration, daily lying time, and pedometer activity were similar in the HEf, LEf, and MEf groups. The HEf cows produced 1.75% more milk, but similar energy-corrected milk compared with the LEf cows. Milk fat and protein content were lower by 1.8 and 3.8%, respectively, in the HEf cows than in the LEf group. Body weight (BW) and BW gain were similar in the 3 efficiency groups. Diurnal distribution of DM intake showed 6 distinct major meals, each composed of 1.1 to 1.6 visits. Higher intake peaks (greater meal size) were found in the LEf cows compared with the HEf group. Daily DM intake was highly correlated (affected) with energy-corrected milk production (r = 0.61), BW (r = 0.4), eating rate (r = 0.57), and visit size (r = 0.54). Energy balance showed that the lower efficiency of the LEf cows was attributed to their excess heat production and energy loss.

Short-day photoperiod (SDPP) during the dry period increases milk production compared to long-day photoperiod (LDPP) in goats. Photoperiod information is sent to the master clock in the suprachiasmatic nuclei (SCN), which send temporal information to peripheral clocks located in every tissue of the body. We hypothesized photoperiod effects on milk production are mediated in part by changes in mammary clocks. Our objective was to determine the effect of photoperiod manipulation during the dry period in goats on core clock genes expression in mammary gland. Multiparous goats (n = 6) were blocked at dry off into two treatments: LDPP and SDPP. Serial mammary biopsies were taken over a 24 h period during three weeks prepartum. Total RNA was isolated, and q-PCR analysis of the core clock genes CLOCK, ARNTL, PER1, CRY1, and CRY2 found exposure to LDPP significantly increased ARNTL (P

The role the mammary epithelial circadian clock plays in gland development and lactation is unknown. We hypothesized that mammary epithelial clocks function to regulate mammogenesis and lactogenesis, and propose the core clock transcription factor BMAL1:CLOCK regulates genes that control mammary epithelial development and milk synthesis. Our objective was to identify transcriptional targets of BMAL1 in undifferentiated (UNDIFF) and lactogen differentiated (DIFF) mammary epithelial cells (HC11) using ChIP-seq. Ensembl gene IDs with the nearest transcriptional start site to peaks were explored as potential targets, and represented 846 protein coding genes common to UNDIFF and DIFF cells and 2773 unique to DIFF samples. Genes with overlapping peaks between samples (1343) enriched cell-cell adhesion, membrane transporters and lipid metabolism categories. To functionally verify targets, an HC11 line with Bmal1 gene knocked out (BMAL1-KO) using CRISPR-CAS was created. BMAL1-KO cultures had lower cell densities over an eight-day growth curve, which was associated with increased (pSod3). Q-PCR analysis also found lower expression of the putative targets, prolactin receptor (Prlr), Ppara, and beta-casein (Csn2). Findings support our hypothesis and highlight potential importance of clock in mammary development and substrate transport.

Short-day photoperiod (SDPP; 8 h light:16 h dark) during the dry period increases milk production compared with long-day photoperiod (LDPP; 16 h light:8 h dark). We hypothesized that the impact of photoperiod on lactation is mediated by alterations in the circadian system. Twelve Saanen goats were blocked at dry off into SDPP (n = 6) and LDPP (n = 6) treatments and mammary biopsies were taken in the middle of light and dark phases at 3 wk prepartum and 5 wk postpartum. Total RNA was isolated, and the expression of clock genes was analyzed by qPCR. SDPP goats produced more milk than LDPP goats (3.15 ± 0.04 vs. 2.7 ± 0.05 kg/d). In the 24 h period, LDPP goats had a greater body temperature than SDPP goats at 3 wk prepartum (39.6 ± 0.06 vs. 39.3 ± 0.1 °C) and 5 wk postpartum (40.1 ± 0.15 vs. 39.7 ± 0.1 °C). Cosinor analysis revealed that physiological state affected body temperature mesor (P

There is absence knowledge about the effects of lactation trimester and parity on eating behavior, production and efficiency of dairy cows. Objective of this study was to identify and characterize in 340 dairy cows, the 20% high efficient (HE), 20% low efficient (LE) and 60% mid efficient (ME) cows according to their individual residual feed intake (RFI) values, within and between lactation trimesters and between 1st and 2nd parities. Efficiency effect within each lactation trimester, was exhibited in daily dry matter intake (DMI), eating rate and meal size, that were the highest in LE cows, moderate in the ME cows and lowest in the HE group. Daily eating time, meal frequency, yields of milk and energy-corrected milk (ECM) and BW were similar in the three efficiency groups within each trimester. The lower efficiency of the LE cows in each trimester attributes to their larger metabolic energy intake, heat production and energy losses. In subgroup of 52 multiparous cows examined along their 1st and 2nd trimesters, milk and ECM production, DMI, eating behavior and efficiency traits were similar with high Pearson's correlation (r=0.78 to 0.89) between trimesters. In another subgroup of 42 multiparous cows measured at their 2nd and 3rd trimesters, milk and ECM yield, DMI and eating time were reduced (Plt;0.01) at the 3rd trimester, but eating rate, meal frequency and meal size remained similar with high Pearson's correlation (r=0.74 to 0.88) between trimesters. In subgroup of 26 cows measured in 1st and 2nd parities, DMI, BW, milk and ECM yield, and ECM/DMI increased in the 2nd lactation, but eating behavior and RFI traits were similar in both parities. These findings encourage accurate prediction of DMI based on a model that includes eating behavior parameters, together with individual measurement of ECM production. This can be further used to identify HE cows in commercial herd, a step necessary for potential genetic selection program aimed to improve herd efficiency.

Circadian clocks influence virtually all physiological processes, including lactation. Here, we investigate the role of the CLOCK gene in regulation of mammary epithelial cell growth and differentiation. Comparison of mammary morphology in late-pregnant wild-type and ClockΔ19 mice, showed that gland development was negatively impacted by genetic loss of a functional timing system. To understand whether these effects were due, in part, to loss of CLOCK function in the gland, the mouse mammary epithelial cell line, HC11, was transfected with short hairpin RNA that targeted Clock (shClock). Cells transfected with shClock expressed 70% less Clock mRNA than wild-type (WT) HC11 cultures, which resulted in significantly depressed levels of CLOCK protein ( P < 0.05). HC11 lines carrying shClock had four-fold higher growth rates ( P < 0.05), and the percentage of cells in G1 phase was significantly higher (90.1 ± 1.1% of shClock vs. 71.3 ± 3.6% of WT-HC11) following serum starvation. Quantitative-PCR (qPCR) analysis showed shClock had significant effects ( P < 0.0001) on relative expression levels of Ccnd1, Wee1, and Tp63. qPCR analysis of the effect of shClock on Fasn and Cdh1 expression in undifferentiated cultures and cultures treated 96 h with dexamethasone, insulin, and prolactin (differentiated) found levels were reduced by twofold and threefold, respectively ( P < 0.05), in sh Clock line relative to WT cultures. Abundance of CDH1 and TP63 proteins were significantly reduced in cultures transfected with sh Clock. These data support how CLOCK plays a role in regulation of epithelial cell growth and differentiation in the mammary gland.

Milk is a major source of iodine in human nutrition. Because both iodine content and the consumption of milk and dairy vary widely over time and populations, their contribution to iodine intake must be evaluated regularly. A recent national iodine survey found Israel's population to be mildly iodine deficient, possibly due to unmonitored changes in the food content of dietary iodine. Accounting for dairy iodine content can help guide efforts to prevent iodine deficiency.This study aimed to determine the iodine concentration of dairy products typically consumed in the Israeli diet, and to estimate iodine intake from dairy products among Israeli adults.Iodine was analyzed in 33 selected dairy products that account for 89% of the total population's dairy intake according to the "MABAT" Israeli National Health and Nutrition survey. Based on these data, the distribution of iodine intake from milk, dairy, and dairy-based foods in the adult population was calculated.Israeli milk is rich in iodine, with a mean concentration of 22 μg/100 g. However, due to low dairy consumption, the mean iodine intake from milk and dairy was only 34 μg/day (median 23 μg/day; range: 0-337 μg/day) or 22% of the recommended daily allowance. Self-reported intake among poor, male, and Arab subgroups was even lower.Because Israeli milk and dairy products are iodine rich, their contribution to the population's iodine intake would increase if they were consumed in greater amounts, particularly by high-risk groups. Dairy's potential contribution to iodine nutrition should be considered in recommendations for dairy consumption and iodine prophylaxis.

Effect of ensiling pomegranate pulp (PP) with or without solid additives on composition and in vitro digestibility was assessed in glass silos. Ensiling of fresh PP solely, resulted in low DM content (185 g/kg) and high fermentation losses (20% of DM). Notwithstanding, ensiling a mixture (on DM basis) of: 40% PP, 35% soy hulls and 25% corn silage, produced pomegranate pulp silage (PPS) characterized by low pH (3.86), appropriate DM content (34.7%), low fermentation losses during ensiling (5.58%) and similar in vitro DM digestibility (66.2%) compared with the raw material. Consequently, this PPS mixture was ensiled in two pressed bales (700 kg each) wrapped with stretch polyethylene film, for measuring PPS intake and digestibility by sheep. A preliminary observation demonstrated that lambs refused to consume diet based just on PPS and soybean plus minerals and vitamins mix. Only after reduction of PPS level in the TMR to 51% of the DM while replacing part of the PPS with wheat hay, the PPS-hay diet was entirely consumed. Therefore, four male Assaf lambs housed in individual metabolic cages, were fed ad-libitum two total mixed rations (TMR) in a cross over design: The PPS TMR contained 51% PPS, 38% chopped wheat hay, and 11% soybean plus minerals and vitamins mix; The reference Hay TMR contained 89% chopped wheat hay plus 11% minerals soybean plus minerals and vitamins mix. This hay-TMR was used to calculate the apparent digestibility of the PPS component in the PPS + Hay TMR. Lambs fed the PPS + hay TMR ingested voluntary 1,129 g DM/lamb/day including 580 g PPS DM/lamb/day. Apparent in vivo digestibility values of the PPS component in the experimental TMR were: dry matter, 60.1%; organic matter, 65.6%; crude protein, 47.1%; and neutral detergent fiber, 46.8%. Notwithstanding, in vitro DM and NDF digestibility of the PPS was higher (67.5% and 52.3%, respectively). The lower in vivo digestibility values compared with the corresponding in vitro data is associated with occurrence of soluble phenolics that are considered entirely digestible in the in vitro system but actually form non-digestible phenol–protein complexes in the sheep gut that reduce in vivo NDF and DM digestibility.

This study examined the chemical composition, in vitro and in vivo digestibility, aerobic stability and ensiling capability of the fresh wet fibrous by-products Aspergillus residue, soy pulp (okara), pomegranate pulp, grape pulp and avocado pulp. Ensiling was assessed in glass silos, and aerobic stability in open PVC containers. Intake and in vivo digestibility were measured in mature male Assaf lambs (four lambs/replicates per dietary treatment) held in individual metabolic cages, and ad libitum-fed one of the total mixed rations containing the examined fresh by-product and appropriate supplement. Aspergillus residue is an acidic, fibrous by-product, characterized by high in vivo digestibility of organic matter (OM, 0.85) and neutral detergent fiber (NDF, 0.95), and high stability under aerobic exposure. Ensiling results give large dry matter (DM) losses (41.2%) and continuous yeast fermentation to ethanol and volatiles. Okara is an acidic, fibrous by-product that is rich in protein (290 g/kg DM), characterized by high in vivo digestibility of OM and NDF (0.88 and 0.93, respectively), but low stability under aerobic exposure. It can be ensiled with moderate DM losses (16%), producing butyrate and acetate. Pomegranate pulp contains high levels of soluble phenolics and sugars and its voluntary consumption by sheep is low. When fed to sheep it is characterized by low in vivo OM and NDF digestibility (0.44 and 0.20, respectively), and low aerobic stability. However, it can be ensiled with moderate DM losses (20%). Grape is rich in ethanol and avocado pulps in fat content, and both byproducts are rich in lignin content and therefore have low in vivo OM digestibility (0.30 and 0.43, respectively) originating from their low NDF digestibility (0.12 and 0.31, respectively). These by-products are characterized by low stability under aerobic exposure. Both by-products can be ensiled without any DM losses or NDF solubilization.

The objective of the present study was to assess the pharmacokinetics of the novel atypical drug tapentadol (TAP) after intravenous (I.V.) and intramuscular (I.M.) injections in clinically healthy goats. A 2 × 2 cross-over design study was carried out. Six local adult Nubian nonlactating, nonpregnant female goats, were given 5 mg/kg body weight of TAP by I.V. and I.M. routes. The concentrations of TAP in plasma were evaluated using a validated HPLC method. Transient adverse effects were noticed in some animals, especially after I.V. administration (tremors and ataxia). Three days after drug administration, severe hair loss was also recorded. The plasma concentrations after the two routes of administration were best described by a bi-compartmental model. After I.M. injection, TAP showed a very fast absorption (Tmax = 0.17 h) and a short half-life (1.29 h). The I.M. bioavailability was quite high, despite being variable (87.8 ± 35.6%). This is the first pharmacokinetic study of TAP in goats but due to its unknown safety profile and efficacy, it is premature to recommend the use of this drug in clinical ovine practice.

Phosphoenolpyruvate carboxykinase (PEPCK) isoforms (c, cytosolic; m, mitochondria) are expressed in the liver and mammary gland. PEPCK-c is a rate-controlling enzyme for gluconeogenesis and glyceroneogenesis; its activity is decreased by insulin. PEPCK-m expression is constitutive and functions to channel lactate toward gluconeogenesis. We hypothesized that the increase in milk protein but decrease in milk lactose and fat when a hyperinsulinemic-euglycemic clamp (HIEC) is applied to dairy goats is due to decreased expression of mammary PEPCK-c mRNA. Late lactation goats (n = 4; 150 ± 30 days in milk) were subjected to saline infusion and HIEC (104 µg insulin/h) for 4-day periods in a 2 × 2 crossover design. On day 4 of each period, a mammary biopsy (~1 g) was taken from an udder half to determine expres- sion of PEPCK-m and PEPCK-c mRNA by real-time RT-PCR. Plasma insulin increased 3.5-fold (P< 0.002) due to the HIEC and euglycemia was maintained. The HIEC decreased (P< 0.0001) dry matter intake (28%) and milk yield (26%). While milk fat content was not affected, HIEC increased (P< 0.001) milk protein content (2.82% vs. 3.09%) but decreased (P< 0.001) milk lactose content (4.22% vs. 4.03%). Expression of PEPCK-m mRNA was 9-fold higher (P< 0.004) than that of PEPCK-c. The HIEC decreased (P< 0.03) PEPCK-c mRNA 7-fold but tended to increase (P< 0.236) PEPCK-m mRNA 1.3-fold. These results demonstrate that insulin regulates mRNA expression of mammary PEPCK isoforms, and this may underlie the changes in milk-component synthesis observed when a HIEC is applied.

The influence of photoperiod manipulation in the dry period was examined in dairy goats experiencing environmental heat stress. Multiparous Israeli Saanen goats were blocked at dry off (∼60 d prepartum) into 2 groups of 4 goats each based on body weight, previous milk production, and detected embryo number. Treatments consisted of long-day (16 h light:8 h dark) and short-day (8 h light:16 h dark) photoperiods (LDPP and SDPP, respectively). Heat-stress conditions were applied by manipulating the environment of metabolic rooms to reach a maximum temperature of 37°C between 1000 and 2200 h, and a minimum of 23°C and 70.3% relative humidity. All goats were returned to ambient photoperiod after kidding, milked twice daily, and milk yield was automatically recorded. Dry matter intake during the dry period was similar between treatments, averaging 1,114 g/d. Milk production was significantly higher in the SDPP than the LDPP group (2,172 vs. 1,550 g/d) during the 12-wk experimental period. Milk protein and fat contents were similar in both groups and averaged 3.63 and 4.34%, respectively, whereas milk lactose was higher in the LDPP group (4.77 vs. 4.67%). Heart rates were similar between treatments and averaged 112.6 beats per minute (BPM). Respiration rates were lower in the morning (58.4 BPM) compared with the afternoon (91.2 BPM) and were not influenced by photoperiod. Rectal temperature was higher for the LDPP than the SDPP group (40.4 vs. 39.6°C). The thyroid hormone level (mean ± SE) was similar in both groups during the dry period, but higher during lactation in the LDPP goats up to 40 d postpartum (110±6.59 vs. 156±8.76 ng/mL). Plasma IGF-1 (mean ± SE) was higher in the LDPP group (279±62 vs. 162±27 ng/mL in SDPP) during the dry period but was similar postkidding, averaging 132±24 ng/mL. Plasma prolactin level (mean ± SE) was higher in the LDPP than the SDPP group during the dry period (17.2±1.6 vs. 10.6±0.99 ng/mL), whereas it was similar throughout lactation (0.61±0.28 ng/mL). These data support the idea that SDPP manipulation during heat load in dry goats can be used as an abatement strategy to reduce the carryover effect of heat stress observed during the subsequent lactation. The higher milk production in SDPP goats is explained by changes in circulating prolactin profile rather than differences in feed intake or secretion of insulin-like growth factor 1.

This study measured the effects of replacing corn silage and vetch hay by soy hulls in total mixed rations (TMRs) fed to 25 pairs of cows through 90 d in milk, on dry matter (DM) intake, in vivo digestibility, milk yield and composition, onset of normal estrous activity, body condition score (BCS), health and the energy balance of lactating cows. The partitioning of metabolizable energy (ME) intake between heat production (HP) and retained energy (RE) in milk and body change of each cow was measured. The two TMRs differed in the content of forage and forage aNDFom [235 g/kg versus 350 g/kg; and 128 g/kg versus 187 g/kg DM, in the experimental (EXP) and control (CON) diets, respectively]. This was reflected by an increase in voluntary DM intake by 7.2% (P=0.02) in the EXP group as compared with the CON. In vivo DM and aNDFom digestibility were 4.9% (P=0.03) and 22.7% higher (P=0.01), respectively, in the EXP group than in the CON. The higher DM intake and digestibility of the EXP TMR were reflected by a concomitant increase of 7.4% in milk yield and 10.8% in RE (P=0.01) of the EXP cows as compared with the CON. The two dietary groups expressed similar somatic cell counts, and metabolic disorders (i.e., ketosis and/or lameness), as well as pedometer activity (steps/h) suggesting similar udder health, behavior and animal welfare. A trend to an earlier return to normal ovarian activity occurred in the EXP cows as reflected by fewer days to 1st ovulation and advanced outset of estrous cycle. Despite the higher RE of the EXP cows, the HP of both groups was maintained at an upper level of 141–136 MJ/cow/d during the 90 d of the experiment.

Effect of evaporative cooling of pregnant dairy cows under heat load conditions during the dry and close-up period, on mammary gland enzymatic activity and intake of food and water, BCS, and milk performance after calving were measured in two consequent experiments. In experiment 1, 18 dry cows held in tie-stalls in a closed aerated barn under heat load conditions were used to measure the effect of evaporative cooling on the respiratory rate and body temperature, individual intake of food and water, enzymes expression level in mammary gland and adipose tissues, and BCS changes until calving. In experiment 2, two groups of 36 dry cows each, held in a commercial loose housing barn, were used to measure the effects of evaporative cooling under heat load conditions on calves' birth weight, colostrum quality and quantity, BCS changes and milk yield during 90 DIM. The non cooled (NC) cows responded to heat load by increasing their respiratory rate and daily water intake, while elevating their rectal temperature by 0.2–0.3 °C as compared with the cooled (C) cows. The external relief of heat load by the C cows in both experiments was expressed in increasing their voluntary DMI during the dry period as compared with the NC group. In experiment 2 the calves' birth weight of C cows was higher, and their colostrum quality and quantity were improved as compared with the NC group. Cooling also improved significantly BCS gain during the last 21 days until parturition, accompanied with higher cell proliferation process (based on enzymes expression at mRNA level) in the mammary gland of the C cows. Consequently, a significant increase in milk production by 5.3%, protein yield by 5.1%, ECM yield by 4.2% and FCM yield by 4.5%, was demonstrated in the C cows during 90 DIM as compared with the NC group.

Leptin, like estrogen, is one of the endo/paracrine factors, which are synthesized in and secreted from mature adipocytes. The roles of the mammary fat pad and mammary adipocytes in the initiation of lactation are not clear. In this study, we showed that combination of prolactin, leptin and estrogen elevated the expression of the milk protein beta-lactoglobulin. We also showed that after prolactin stimulate the secretion of leptin from the mammary fat, leptin upregulated the expression of estrogen receptor alpha in the mammary epithelial cells. Also, prolactin affected aromatase mRNA expression in the bovine mammary fat and we demonstrated that leptin and prolactin can affect cholesterol secretion from explants in culture to the medium. Therefore, we suggest that prolactin initiates estrogen expression (as represented by aromatase mRNA) in the mammary fat pad, whereas leptin stimulates estrogen receptor alpha expression in the mammary epithelial cells. We hypothesize that leptin and estrogen, secreted from the mammary fat regulate lactation after stimulation of prolactin.

The objective of this study was to measure the effect of feeding two total mixed rations (TMRs), differing in their roughage content and in vitro dry matter digestibility, on the respiratory rate, body temperature, eating behavior and energy balance of lactating cows. The partitioning of metabolizable energy intake (MEI) between heat production (HP) and retained energy (RE) of cows held under heat load conditions was measured. Forty-two lactating cows were divided into two similar sub-groups, each of 21 animals, and were fed either a control (CON) ration containing 18% roughage neutral detergent fiber (NDF) or an experimental (EXP) TMR that contained 12% roughage NDF and used soy hulls as partial wheat silage replacer. The in vitro DM digestibility of the CON and EXP TMRs was 75.3 and 78.6%, respectively (P

Four multiparous pregnant Nubian goats at late lactation were subjected to injection of a saponin preparation from Gypsophila roots. Saponin solution was injected into one single gland of each goat after milking 8 times. At day 2 in treatment, milk yield began to be affected, and dropped down dramatically from day 3 till dry off at day 8. The pH value of milk was increased in udder halves treated with the saponin solution after 2 days, whereas the control halves exhibited semi-plateau manner all over the experiment. Sodium concentration increased and potassium concentration decreased af- ter 2 d in treatment. Calcium concentration in the treated udder declined after 8 d and the values of these ions were round- about the plasma concentrations indicating that milk secreted from the treated udder halves with saponins was mostly composed of interstitial fluid.

Based on a previous ensiling study in glass silos of various pomegranate pulp (PP) mixtures, fresh pomegranate pulp (PP) was mixed with drier feeds including soy hulls and corn silage (40:35:25 on DM basis) and ensiled in 32 pressed bales (700 kg each) wrapped with stretch polyethylene film. This ensiled pomegranate pulp mixture (PPM) was included in lactating cow total mixed ration (TMR) at a level of 20% of DM (PPM-TMR). Performance and digestion experiment was conducted with two groups of 21 milking cows each, fed individually one of the two TMR: 1. Control TMR without ensiled PPM; 2. Experimental TMR which contained 20% ensiled PPM, including 8% PP as corn grain replacer. Voluntary DM intake of cows fed the control TMR was 5·04% higher than that of the PPM cows. In vivo digestibility of DM, OM, NDF, CP and fat were significantly higher in the control cows compared with the PPM group, but methane production in the rumen fluid was 25% lower in the PPM cows. A slightly higher milk yield (by 2·2%) observed in the control cows; however, milk fat content was 5·9% higher in the PPM cows. This was reflected in similar yield of energy corrected milk (ECM) and 3·97% increase in production efficiency (ECM/DM intake) of the PPM cows compared with the control ones. Welfare of the cows, as assessed by length of daily recumbence time, was in the normal range for both groups. Body weight gain was also similar in both groups. Data suggest that the level of 8% PP in the PPM-TMR used in this study was probably too high for lactating cows and should be lowered to 4% in order to achieve better performance.

Four Israeli mix-breed Saanen dairy goats were used in a 2×2 factorial design to evaluate the effect of the level of dietary crude protein (CP) and ruminally degradable OM (RDOM) concentration on the production, composition and efficiency of milk production under hot ambient conditions. Daily ration comprised of 30% hay and 70% concentrates was divided into 12 equal meals. Treatment factors were 18% (HCP) or 15% (LCP) of CP in the diet DM, and 56% (HRDOM) or 50% (LRDOM) of RDOM. Goats were housed in metabolic crates in air-conditioned room. Air temperature ranged between 25 °C and 36 °C, and the thermal humidity index (THI) between 74 and 90 units. Daily amplitude of goat's body temperature was 1.2 °C and was unaffected by treatments. The DM intake, milk yield, and concentrations of protein, fat, and lactose, as well as total tract apparent digestibility of DM and OM were similar among treatments (P>0.1). Digestibility of CP was higher in the HCP diets (P 0.1), while NEFA level was higher in LRDOM (P

This study examined the localization and the effect of circulating peptides on the expression of aminopeptidase N (EC 3.4.11.2) in caprine mammary gland. Four lactating goats in mid to late lactation were used in a crossover design and were subjected to 2 dietary treatments. Abomasal infusion of casein hydrolysate was used to increase the concentration of peptide-bound amino acid in the circulation. Samples of mammary gland tissue from each goat were taken by biopsy at the end of each treatment period to measure gene and protein expression of aminopeptidase N in the tissue. There were no measurable effects on feed intake and milk production for any of the treatments. Western blot analysis showed that aminopeptidase N is located on the basolateral side of parenchymal cells and not on the apical membranes. Abomasal infusion of casein hydrolysate caused a marked change in the profile of arterial blood free amino acids and peptide-bound amino acids smaller than 1500 Da. Abundance of aminopeptidase N mRNA and protein increased by 51 and 58%, respectively, in casein hydrolysate-infused goats compared with the control treatment. It was concluded that aminopeptidase N is one candidate actively involved in the mammary gland to support protein synthesis and milk production. In accordance with the nutritional conditions in the current experiment, it is suggested that aminopeptidase N expression is partly controlled by the metabolic requirements of the gland and postabsorptive forms of amino acids in the circulation.

The current ruminant protein systems aim at synchronizing the provision of rumen degradable organic matter (RDOM) and degradable crude protein (RDCP) but no specific information on their optimal ratio for dairy sheep is available. We studied the effect of the ratio of RDOM to RDCP on milk yield and composition, during a summer lactation, in 34 confined Assaf sheep managed under farm condition. Individual feed intake was assessed by using PEG (MW 4000) as external marker of fecal output, and indigestible INDF as internal marker of digestibility. Four total mixed rations contained two levels of RDCP (108 and 117 g/kg DM) and two levels of RDOM (510 and 570 g/kg DM). This resulted in one diet featuring high (5.3), one diet featuring medium (4.8) ratio, and two diets featuring low (4.5) ratio of RDOM to RDCP. Individual DM intake, digestibility, and the daily yields of milk components were not affected by RDOM, RDCP or RDOM/RDCP. High RDOM/RDCP tended ( P < 0.10) to be associated with higher milk yield, and lower (P < 0.05) CP content. The casein/CP ratio and urea-N in milk were lowest when both dietary RDCP and RDOM were low, whereas lactose was highest (P < 0.05) when both RDOM and RDCP concentrations were high. Our data suggest that RDOM and RDCP interact on milk composition in a way that is not fully encompassed by the RDOM/RDCP ratio and that the use of this ratio to formulate diets for pre-determined milk composition is not warranted. © 2004 Elsevier B.V. All rights reserved.

Leptin, a protein hormone produced and secreted predominantly by white adipose tissue, has a critical role in the regulation and coordination of energy metabolism. Identification of leptin in the milk of several mammals, including humans, led us to investigate its presence and regulatory effect in the cow mammary gland. The expression of leptin receptor in tissue culture of lactating mammary gland was augmented approximately 25 times by prolactin, but had no effect on virgin calf mammary tissue. Expression of leptin in tissue culture from mammary glands of lactating cows was enhanced 2.2-fold by prolactin. No effect of prolactin on leptin and leptin receptor expression was found in mammary gland tissue culture from calves. Leptin-enhanced fatty acid synthesis in the presence of prolactin, but had no effect without presence of prolactin. A similar pattern was found in the expression of alpha-casein and beta-lactoglobulin in mammary gland explants from a lactating cow. Our findings indicate that leptin plays an important role in mammary gland lactogenesis, and that the expression of leptin requires the presence of prolactin.

The Na+-K+-ATPase, localized in the basolateral membrane of enterocytes plays a major role in nutrient transport in the small intestine by transferring K+ ions into and Na+ out of the cell. Within the enterocyte, homeostasis is maintained by active exclusion of Na from the cell by the Na+,K+-adenosine triphosphatase (ATPase) or sodium pump. Because much of the intestinal nutrient transport is by Na cotransporters, Na+,K+-ATPase may be used to evaluate nutrient uptake. In this study, nutrient transport was evaluated by determining expression and activity of Na+-K+-ATPase in the jejunum of chicks fed diets with different concentrations of Na. Expression of the chicken Na+-K+-ATPase gene was examined following isolation of an 1,140 bp cDNA fragment of the alpha-subunit using a reverse transcription (RT)-PCR reaction with specific primers. This fragment was sequenced and showed 95 to 98% homology with the mammalian alpha-subunit of the Na+-K+-ATPase genes. This cDNA fragment was used as a specific probe in Northern blot hybridization for determination of expression in the chicken jejunum. Expression of mRNA of Na+-K+-ATPase was enhanced at low dietary Na but was unchanged at high dietary Na concentrations. In contrast, activity of the enzyme was low with low dietary Na and unchanged at high dietary Na. The Vmax of the Na+-K+-ATPase was unchanged, but affinity was altered by dietary Na concentrations. Thus, determination of expression and activity of intestinal Na+-K+-ATPase allows clearer understanding of changes in intestinal uptake due to dietary Na.

Polyethylene glycol (PEG) is used to neutralize the effects of dietary tannins on nutrient digestibility. We have shown previously that it can be used as a marker of fecal output of goats fed tannin-free diets, and be accurately quantified by using near infrared reflectance (NIR) spectroscopy. However, its analysis can be complicated by the presence of tannins. In experiment 1, using the mixtures of feces, PEG and quebracho tannin (QT), we showed that QT interferes with PEG at NIR segments featuring OH-stretching and bending (2090 nm), but not at segments featuring CH stretch and CH 2 deformation (2280 nm). In experiment 2, we used calibrations of PEG in the feces of goats fed a tannin-free diet to predict PEG content in the feces of goats supplemented with QT. When goats were given 15 g per day of PEG, without QT, the analytical recovery of PEG in feces was 97.8%. However, when they also received QT, the analytical PEG recovery was only 42.7%, when calculated with a calibration equation using the whole NIR range (1100–2498 nm). Analytical recovery increased to 93.5% when a single wavelength (2280 nm) calibration equation was used. The problem of PEG–tannin bonding seems to be almost totally overcome by using calibration equations relying on the NIR segments where no chemical moieties involved in the PEG–tannin bonding are found. PEG, when provided to goats feeding on tannin-containing diets, can also probably serve as a marker of fecal output in goats.

The response in dairy cows fed high-concentrate diets to abomasal infusion of lysine (Lys) and methionine (Met) at two levels of dietary CP was examined. Four multiparous Israeli Holstein cows (day in milk = 180±30, means ± SE) were utilized in a 4 x 4 Latin square design experiment that included a 2 x 2 factorial arrangement with 18-d periods. Cows were surgically prepared with abomasal cannulae and catheters implanted in the costoabdominal artery. Two diets were composed to contain high and low crude protein (CP) content (152 vs 132 g/kg dry matter). Abomasal infusion of either water or Lys (38 g/d) plus Met (14 g/d) was performed with each diet. On the last day of the experimental period the metabolism of amino acids (AA) across the mammary gland was monitored. Dry matter intakes and milk and protein yields were not affected by either dietary CP level or postruminal infusion of Lys plus Met and averaged 15.9, 21.4, and 0.694 kg/d, respectively. Milk fat content and yield were not affected by dietary CP concentration, but did increase with abomasal infusion of Lys plus Met (33.3 vs 37.2 g/kg; P

US scientists, Dr. Theresa Casey and Dr. Karen Plaut, collaborated with Israeli scientists, Dr. SameerMabjeesh and Dr. AviShamay to conduct studies proposed in the BARD Project No. US-4715-14 Photoperiod effects on milk production in goats: Are they mediated by the molecular clock in the mammary gland over the last 3 years. CLOCK and BMAL1 are core components of the circadian clock and as heterodimers function as a transcription factor to drive circadian-rhythms of gene expression. Studies of CLOCK-mutant mice found impaired mammary development in late pregnancy was related to poor lactation performance post-partum. To gain a better understanding of role of clock in regulation of mammary development studies were conducted with the mammary epithelial cell line HC11. Decreasing CLOCK protein levels using shRNA resulted in increased mammary epithelial cell growth rate and impaired differentiation, with lower expression of differentiation markers including ad herens junction protein and fatty acid synthesis genes. When BMAL1 was knocked out using CRISPR-CAS mammary epithelial cells had greater growth rate, but reached stationary phase at a lower density, with FACS indicating cells were growing and dying at a faster rate. Beta-casein milk protein levels were significantly decreased in BMAL1 knockout cells. ChIP-seq analysis was conducted to identify BMAL1 target genes in mammary epithelial cells. Studies conducted in goats found that photoperiod duration and physiological state affected the dynamics of the mammary clock. Effects were likely independent of the photoperiod effects on prolactin levels. Interestingly, circadian rhythms of core body temperature, which functions as a key synchronizing cue sent out by the central clock in the hypothalamus, were profoundly affected by photoperiod and physiological state. Data support that the clock in the mammary gland regulates genes important to development of the gland and milk synthesis. We also found the clock in the mammary is responsive to changes in physiological state and photoperiod, and thus may serve as a mechanism to establish milk production levels in response to environmental cues.

The effect of infusing similar energy equivalents of starch into the rumen, or starch or oil into the abomasum was studied in four midlactation cows in a 4 x 4 Latin square design experiment; controls were ruminally infused with water. Cows were fitted with cannulas in the rumen, abomasum, and ileum, and nutrient digestion in the rumen and small intestine was evaluated with Cr as a digesta marker. Ruminal infusions of starch, or abomasal infusions of starch or oil, were associated with a decrease in voluntary feed organic matter intake. Overall energy intake was reduced in oil-infused, but not in starch-infused cows. Nonstructural carbohydrate digestibility in the rumen and in the small intestine was similar among treatments. In abomasally infused cows 3.4 kg/d of nonstructural carbohydrates was apparently digested in the small intestine. Milk production was reduced in oil-infused cows, but the efficiency of milk energy and protein yield was unaffected by treatments. Plasma glucose, insulin, and IGF-1 concentration, mammary glucose extraction rate, rumen ammonia and plasma urea, and arterial and mammary extraction rate of amino acids were all similar among treatments. Large quantities of starch can be digested in the rumen or small intestine of dairy cows. There appear to be no metabolic advantage to increasing the supply of starch to the rumen or the abomasum of mid-lactation dairy cows maintained on highly concentrated diets and exhibiting a positive energy balance.

We partitioned the flow of amino acids (AA) to the abomasum among rumen undegradable protein (RUP) and bacterial, protozoal, and endogenous fractions using four Holstein cows in midlactation that were equipped with ruminal and abomasal cannulas. A 2 x 2 factorial design with four diets, combinations of high or low ruminally degradable organic matter, and rumen degradable protein, was employed. Crude protein (CP) and AA contents of ruminal bacteria and protozoa and abomasal digesta were determined. Equations for the source compositions and in vivo flows of CP and 16 AA were then solved simultaneously with a linear program to estimate the contribution of RUP, bacterial, protozoal, and endogenous CP to AA flows. The flows of RUP and bacterial AA were not affected by diet. Low dietary RDP increased the flow of protozoal AA to the abomasum, but the ruminally degradable organic matter content of the diet did not affect protozoal AA flow. Across diets, RUP, bacterial, protozoal, and endogenous fractions provided 55, 33, 11, and

The combined bag technique was used to estimate digestible energy of ruminant feedstuffs. Samples of corn, barley, and sorghum grains; soybean and sunflower meals; corn and wheat silages; and vetch and wheat hays were incubated in dacron bags in the rumens of dairy cattle for 3 to 72h. Bags containing residues after 12h of ruminal incubation were introduced into the duodenum and recovered from feces. Feeds and ruminal and intestinal residues were analyzed for dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber, and nonstructural carbohydrates. The effective ruminal degradability of OM was higher in grains (639 g/kg of DM) and in protein supplements (609 g/kg of DM) than in forages (373 g/kg of DM). For grains and forages, carbohydrates contributed most of the degradable OM in the rumen, but, in protein supplements, about 50% of the ruminally degradable OM originated from carbohydrate. For protein supplements, 54% of the OM that disappeared postruminally was CP, but, in the grains and forage ingredients, CP contributed less than 20% of the postruminal OM that disappeared. In grains and forages, 83% of total tract disappearance of OM was from carbohydrates. For protein supplements, CP contributed 50% to overall OM disappearance. The calculated energy equivalent of digested matter averaged among feeds was 4.71 kcal/g. A high correlation was found between digestible energy estimated by the combined bag technique and the respective National Research Council values. The combined bag technique is a useful tool for the estimation of digestible energy in feedstuffs.

The effect of heat treatment on the nutritive value of rumen undegradable protein (UDP) fraction of whole cottonseed (WCS) was studied in this experiment. Forty two multiparous Israeli Holstein cows were used in a multiple double 3×3 Latin square design. Milk production averaged 38±4.1 kg at the beginning of the experiment. Three different diets were formulated to contain 160 g/kg crude protein (CP), 365 g/kg neutral-detergent fibre (NDF) on a dry matter (DM) basis, 7.24 MJ net energy for lactation (NE L )/kg DM and 170 g/kg WCS. 30% of dietary CP was of cotton origin. Diets were (1) whole cottonseed (WCS), (2) heated whole cottonseed (HWCS) and (3) whole cotton seeds plus 3.1% maize gluten meal (WCS+MG). Diets with HWCS and WCS+MG contained 60 g UDP/kg DM compared with 54 g UDP/kg DM in the WCS treatment. Heat treatment decreased ruminal CP degradability of WCS by 22% and ruminal organic matter (OM) degradability by 5%. Intakes of DM, OM and CP were similar across diets. Higher apparent total tract digestibilities of DM and OM were determined in HWCS and WCS+MG diets (0.62 and 0.64 and 0.63 and 0.65, respectively) compared to WCS diet (0.59 and 0.62, respectively). Higher ruminal propionate proportion was determined in diets containing WCS and WCS+MG over the sampling hours. A higher ruminal ratio of acetate:propionate was measured in the diet containing HWCS. Ammonia N concentration was similar in all treatments, however, blood urea N concentration was the lowest at 3 and 6 h after feeding in the HWCS diet compared to the other diets. Milk yield and composition were similar for all treatments and averaged 34.2±0.45 kg/d with 34.2 g fat/kg, 30.1 g CP/kg and 47 g lactose/kg. It was suggested that inclusion of HWCS in diets for high-yielding dairy cows decreased the endogenous catabolism of amino acids. In this study the effect of heat treatment on WCS on the performance of cows was not apparent because the cows consumed surplus of dietary CP.

This study analyzed the relationships among the effective degradabilities of organic matter (OM) in feedstuffs, which were assessed separately by an in situ method and a direct in vivo measurement of the rumen degradation of OM in the diets of Holstein dairy cows. For this comparison, 80 individual data points were used from studies of dairy cows that were in midlactation and that had been cannulated in the rumen and abomasum. In vivo evaluation of the true degradability of OM in the rumen was based on rare earth digesta markers. Purine N served as a microbial marker. Feed samples were incubated in the rumens of dairy cows for 3, 6, 9, 12, 24, 48, and 72 h, and effective rumen degradation was calculated from the percentage of residual OM for rumen outflow rates of 4, 6, and 8%/h. Evaluations of rumen degradability of OM by the in situ method were correlated with actual in vivo measurements of rumen degradability of OM (r2 = 0.31, 0.34, and 0.37; SE of the estimate = 4.1, 4.0, and 3.9%, respectively). We concluded that the in situ method is a useful tool for providing reliable estimates of rumen degradability of OM in dairy cows.

Lignin biodegradation by white-rot fungi is pivotal to the earth's carbon cycle. Manganese peroxidases (MnPs), the most common extracellular ligninolytic peroxidases produced by white-rot fungi, are considered key in ligninolysis. Pleurotus ostreatus, the oyster mushroom, is a preferential lignin degrader occupying niches rich in lignocellulose such as decaying trees. Here, we provide direct, genetically based proof for the functional significance of MnP to P. ostreatus ligninolytic capacity under conditions mimicking its natural habitat. When grown on a natural lignocellulosic substrate of cotton stalks under solid-state culture conditions, gene and isoenzyme expression profiles of its short MnP and versatile peroxidase (VP)-encoding gene family revealed that mnp2 was predominately expressed. mnp2, encoding the versatile short MnP isoenzyme 2 was disrupted. Inactivation of mnp2 resulted in three interrelated phenotypes, relative to the wild-type strain: (i) reduction of 14% and 36% in lignin mineralization of stalks non-amended and amended with Mn(2+), respectively; (ii) marked reduction of the bioconverted lignocellulose sensitivity to subsequent bacterial hydrolyses; and (iii) decrease in fungal respiration rate. These results may serve as the basis to clarify the roles of the various types of fungal MnPs and VPs in their contribution to white-rot decay of wood and lignocellulose in various ecosystems.

Four multiparous lactating Holstein cows, fitted with cannulas in the rumen, duodenum, and ileum, were used in a trial with a 4 × 4 Latin square design to examine the effect of source and degradability of dietary CP supplements on AA flow and absorption in the small intestine. The CP supplements consisted of fish meal or meat meal as the animal by-products supplement and soybean meal or heated soybean meal as the plant by-products supplement. Fish meal and heated soybean meal constituted the high RUP diets, and meat meal and soybean meal constituted the low RUP diets. Dry matter intakes were similar among treatments. However, intakes of OM, rumen-degradable OM, total CP, and RDP were affected by the source of the CP supplement and were higher for diets with plant by-products than for those diets with animal by-products. Data were similar for the calculated in situ digestibilities and for true in vivo digestibilities of rumen-degradable OM. Efficiency of bacterial CP synthesis was similar among diets; however, nonbacterial CP flow to the duodenum and OM, CP, and disappearance of AA from the small intestine were affected by the interaction of supplement source and degradability. Heat treatment of soybean meal reduced the availability of most of the essential AA for absorption in the small intestine by 2.3% compared with that of soybean meal; the biggest such reduction (20%) occurred for Met. Availability of AA in the small intestine was affected by source and degradability of the CP dietary supplement. Heat treatment at 140°C for 2.5h reduced the availability of Met absorption from the small intestine. Although the differences among availabilities of the individual AA in the small intestine ranged from 80 to 84% among treatments, for high yielding cows, these differences may have practical significance.