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The objectives of this study were to (1) quantify current reproduction management practices, and (2) assess the association between these practices and herd reproductive performance on dairy farms in Canada. A bilingual survey was developed, validated, and administered from March to May 2014 to collect general and reproduction management and performance measures [annual 21-d pregnancy rate (PR), 21-d insemination rate (IR), and conception risk (CR)]. Associations between management practices and reproductive performance measures were tested using linear regression models. A total of 832 questionnaires were completed online and by mail, representing a response rate of 9%. On average, farms had 77 lactating cows (median = 50) and 13 dry cows (median = 10), and Holstein was the most common breed (92% of herds). Lactating cow housing was tiestall on 61% of the farms, freestall on 37%, and bedded pack on 2%. The average voluntary waiting period was 58 d in milk (DIM). The main reproduction management practice per farm was defined as the means employed for >50% of inseminations. Farms reported their main reproduction management practice for first and subsequent inseminations, respectively, as visual estrus detection (51 and 44% of herds), timed AI (21 and 23% of herds), automated activity monitoring (AAM; 10 and 10% of herds), other management practice (bulls; 2 and 2% of herds), and a combination of management practices (16 and 21% of herds). On farms using visual estrus detection, cows were observed for signs of estrus on average 3.5 times per day, for an average total of 36 min/d. The most common use of reproductive hormones was to synchronize ovulation using Ovsynch (58% of the farms). Average PR, IR, and CR were 17.6, 44.1, and 40.5%, respectively. In linear regression analyses adjusted for confounders, pregnancy rate was significantly associated with geographic region, housing (tiestall: PR = 15.4%, freestall: PR = 17.6%), herd size (<50 lactating cows: PR = 16.2%, 50-100 cows: PR = 16.5%, >100 cows: PR = 17.8%), voluntary waiting period (≤60 DIM: PR = 17.6%, >60 DIM: PR = 15.9%), and frequency of insemination per day (once daily: PR = 16.6%, twice or more daily: PR = 18.1%). The main reproduction management practice at first and subsequent inseminations was divergently associated with IR and CR, but not with PR (visual heat detection: PR = 17.4%, timed AI: PR = 18.4%, AAM: PR = 17.1%, combined practices: PR = 18.2%). [ABSTRACT FROM AUTHOR]

Objectives were to determine effects of lactation and pregnancy on endometrial gene expression on d 17 of the estrous cycle and pregnancy. Heifers (n = 33) were assigned randomly after parturition to lactating (L, n = 17) or nonlactating (NL, n = 16) groups. Cows were subjected to an ovulation synchronization program for a timed artificial insemination (TAI); 10 cows in L and 12 in NL were inseminated. Slaughter occurred 17 d after the day equivalent to TAI, and intercaruncular endometrial tissues were collected. Gene expression was determined by DNA microarray analysis for pregnant (L, n = 8; NL, n = 6) and noninseminated cyclic (L, n = 7; NL, n = 4) cows. Differentially expressed genes were selected with a P-value <0.01 and absolute expression >40. In addition, a fold effect >1.5 was used as a criterion for genes affected by pregnancy. In total, 210 genes were differentially regulated by lactation (136 downregulated and 74 upregulated), and 702 genes were differentially regulated by pregnancy (407 downregulated and 295 upregulated). The interaction effect of pregnancy and lactation affected 61 genes. Genes up- and downregulated in pregnant cows were associated with several gene ontology terms, such as defense response and interferon regulatory factor, cell adhesion, and extracellular matrix. The gene ontology analyses of up- and downregulated genes of lactating cows revealed terms related to immunoglobulin-like fold, immune response, COMM domain, and non-membrane-bounded organelle. Several genes upregulated by lactation, such as IGHG1, IGLL1, IGK, and TRD, were related to immune function, particularly for B cells and γ T γᵟ cells. Developmental genes related to limb and neural development and glucose homeostasis (e.g., DKK1, RELN, PDK4) were downregulated by lactation, whereas an interaction was also detected for RELN. The stated genes associated with immune function and developmental genes expressed in the endometrium affected by lactational state are possible candidate genes for interventions to improve fertility of lactating dairy cows. [ABSTRACT FROM AUTHOR]

Objectives were to characterize postpartum metabolic and hormonal differences between nonlactating and lactating dairy cows, evaluate lactation and pregnancy effects on endometrium and conceptus expression of selected genes, and characterize associations between conceptus and endometrial expression of genes in early pregnancy (d 17). Pregnant heifers were assigned randomly after calving to a lactating group (L, n = 17) and a nonlactating group (NL, n = 16). The L cows were fed a total mixed ration [1.65 Mcal of net energy for lactation (NEL)/kg, 16.5% crude protein (CP)] ad libitum, and the NL cows were fed a maintenance ration (1.45 Mcal of NEL/kg, 12.2% CP) once per day. All cows were presynchronized and enrolled in a timed artificial insemination (TAI) protocol; 10 cows in the L and 12 in the NL received TAI. On d 17 after GnRH and TAI, cows were slaughtered and endometrial and conceptus tissues collected. The Affymetrix Bovine Genome DNA Microarray (Affymetrix Inc., Santa Clara, CA) was used to assess conceptus and endometrial gene expression. The L cows had higher body temperature than the NL cows (38.4 vs. 38.2°C), and the NL cows cycled earlier than the L cows (26.3 vs. 34.7 d in milk). Cows in the L group had greater plasma concentrations of β -hydroxybutyrate (4.90 vs. 2.97 mg/dL) and blood urea N (11.6 vs. 6.5 mg/dL) and lower concentrations of glucose (74.0 vs. 79.9 mg/dL) compared with NL cows. Insulin-like growth factor-1 was lower for L compared with NL (140.5 vs. 198.2 ng/mL) and was greater for cows subsequently classified pregnant compared with cyclic (191.0 vs. 147.6 ng/mL). The concentration of progesterone from GnRH or TAI (d 0) until d 17 was lower for L cows than for NL cows. Gene expression analyses indicated that all conceptuses (n = 13) expressed pregnancy-associated glycoprotein (PAG) genes PAG2, PAG8, PAG11, and PAG12. The same PAG family genes were observed in the endometrium of some pregnant cows. Simple and standard partial correlation analyses detected associations of conceptus PAG11 with prostaglandin regulatory genes. In conclusion, lactation altered metabolic status, delayed initiation of cyclicity, and decreased concentrations of progesterone in pregnant cows. Early expression of PAG genes in the conceptus may contribute to successful development of early pregnancy and possibly alter mechanisms related with embryo survival such as prostaglandin synthesis. [ABSTRACT FROM AUTHOR]

Objectives were to compare the effect of presynchronization and resynchronization methods on fertility responses of grazing dairy cows at first and second artificial insemination (AI) and pregnancy rate during the entire breeding season. Lactating dairy cows (n = 1,263) in 2 seasonal grazing farms were blocked, within farm, by parity, breed and days in milk. Within each block, cows were randomly assigned to 1 of 4 treatments arranged as a 2 x 2 factorial with 2 presynchronization and 2 resynchronization treatments. Cows had their estrous cycles presynchronized with either a PGF2α-based program (Presynch) consisting of 2 injections of PGF2α administered 14 d apart and starting the timed AI protocol 11 d later, or with a PGF2α-GnRH-based presyn-chronization program (G6G) consisting of an injection of PGF2α, followed 3 d later by an injection of GnRH and starting the timed AI protocol 6 d later. All cows received the first insemination on the same day, which was considered study d 0 and also d 0 of the breeding season. All cows received the 5-d timed AI protocol that consisted of GnRH on d -8, PGF2α on d -3 and -2, and GnRH + timed AI on d 0. Blood was sampled and analyzed for progesterone on d -8. On d 12, cows in each presynchronization treatment either remained as untreated controls (RCON) or received a controlled internal drug-release (CIDR) insert containing progesterone for 7 d (RCIDR). Estrus was observed daily starting on d 19 and cows in estrus were inseminated on the same day. On d 35, bulls were placed with the cows for an additional 65 d, completing a 100-d breeding season. Holstein cows were less likely to have progesterone ≥1 ng/mL on d -8, and had less expression of estrus and pregnancy per AI (P/AI), which resulted in a slower rate of pregnancy and a smaller proportion of pregnancy at the end of the study than did Jersey or crossbred cows. In addition, body condition, days in milk, and plasma progesterone concentration at the first GnRH injection of the timed AI protocol had marked effects on the reproductive performance of lactating grazing dairy cows. A greater proportion of G6G cows had progesterone ≥1ng/mL at the first GnRH injection of the timed AI protocol compared with Presynch cows (82.0 vs. 74.3%). Presynchronization treatment did not influence P/AI, but cows in G6G had increased risk of pregnancy loss between d 30 and 65 after the first AI (12.9 vs. 8.1%). Nevertheless, an interaction between presynchronization and ovarian status was observed, and cows initiating the timed AI with progesterone ≥1 ng/mL had greater P/AI when previously treated with Presynch than G6G. On the other hand, G6G benefited P/AI of cows initiating the timed AI with progesterone <1 ng/mL. Resynchronization with RCIDR altered the pattern of return to estrus, but it did not increase the rate of re-insemination and decreased the proportion of pregnant cows at the end of the 100-d breeding period (80.6 vs. 84.4%). [ABSTRACT FROM AUTHOR]

Two experiments evaluated the influence of altering the concentrations of progesterone during the development of the ovulatory follicle on the composition of the follicular fluid, circulating LH and PGF2α metabolite (PGFM), and expression of endometrial progesterone receptor and estrogen receptor-a. In both experiments, the estrous cycles were presynchronized (GnRH and progesterone insert followed by insert removal and PGF2α 7 d later, and GnRH after 48 h) and cows were then enrolled in 1 of 2 treatments 7 d later (study d -16): high progesterone (HP) or low progesterone (LP). In experiment 1 (n = 19), cows had their estrous cycle synchronized starting on study d -9 (GnRH and progesterone insert on d -9, and insert removal and PGF2α on d -2). In experiment 2 (n = 25), cows were submitted to the same synchronization protocol as in experiment 1, but had ovulation induced with GnRH on study d 0. In experiment 1, plasma was sampled on d -4 and analyzed for concentrations of LH; the dominant follicle was aspirated on d 0 and the fluid analyzed for concentrations of progesterone, estradiol, and free and total IGF-1. In experiment 2, follicular development and concentrations of progesterone and estradiol in plasma were evaluated until study d 16. Uterine biopsies were collected on d 12 and 16 for progesterone receptor and estrogen receptor-a protein abundance. An estradiol/oxytocin challenge for PGFM measurements in plasma was performed on d 16. In experiments 1 and 2, LP cows had lower plasma concentrations of progesterone and greater concentrations of estradiol, and had larger ovulatory follicle diameter (20.4 vs. 17.2 mm) at the end of the synchronization protocol than HP cows. Concentration of LH tended to be greater for LP than HP cows (0.98 vs. 0.84 ng/ mL). The dominant follicle of LP cows had greater concentration of estradiol (387.5 vs. 330.9 ng/mL) and a lower concentration of total IGF-1 (40.9 vs. 51.7 ng/ mL) than that of HP cows. In experiment 2, estradiol and progesterone concentrations did not differ between treatments from d 0 to 16; however, the proportion of cows with a short luteal phase tended to increase in LP than HP (25 vs. 0%). Concentrations of PGFM were greater for LP than HP. Uterine biopsies had a greater abundance of progesterone receptor, and tended to have less estrogen receptor-a abundance on d 12 compared with d 16. An interaction between treatment and day of collection was detected for estrogen receptor-α because of an earlier increase in protein abundance on d 12. Reduced concentrations of progesterone during the development of the ovulatory follicle altered follicular dynamics and follicular fluid composition, increased basal LH concentrations, and prematurely increased estrogen receptor-a abundance and exacerbated PGF2α release in the subsequent estrous cycle. [ABSTRACT FROM AUTHOR]

Objectives were to evaluate the effects of differing progesterone concentrations during follicle development on follicular dynamics, fertilization, and embryo quality. Lactating Holstein cows (n = 154) were assigned randomly to 1 of 2 treatments. Cows underwent a presynchronization of the estrous cycle composed of an injection of GnRH concurrently with the placement of a progesterone insert, an injection of PGF2α and insert removal 7 d later, and a second injection of GnRH 48 h later (study d -16). All cows were then submitted to a hormonal protocol identical to the presynchronization program starting on d 7 of the estrous cycle (study d -9). Cows enrolled in the high progesterone (HP) treatment received no further treatment. Cows in the low progesterone (LP) treatment received additional PGF2α injections on study d -14, -13.5, and -13 and again on study d -9, -7, -6.5, and -6. Ovaries were evaluated by ultrasonography, and blood was sampled for concentrations of progesterone and estradiol throughout the study. Uteri were flushed 6 d after artificial insemination (AI) and recovered oocytes-embryos were evaluated. Concentrations of progesterone were less for LP cows from study d -7 to -2; concentrations of estradiol at PGF2α and at the last GnRH of synchronization were greater for LP than HP. The proportion of cows in estrus at AI was greater for LP than for HP (38.0 vs. 5.3%). Ovulatory follicles of LP cows had larger diameters at the injections of PGF2α (17.2 vs. 14.6 mm) and final GnRH (19.4 vs. 16.9%) of the synchronization, which resulted in a larger diameter of the corpus luteum 6 d after AI (24.3 vs. 22.6 mm). Double ovulation after the last GnRH of the synchronization was increased in LP (18.6%) compared with HP (4.5%). Fertilization rate was similar and averaged 82.7%. The proportion of embryos and oocytes-embryos classified as grades 1 and 2, proportion of degenerated embryos, and unfertilized-degenerated oocytes-embryos were not different between LP and HP. Number of blastomeres did not differ between LP and HP, but the proportion of live blastomeres tended to be less for LP than HP (94.2 vs. 98.7%). Reducing progesterone concentrations during the synchronization program altered concentrations of estradiol and follicular dynamics, but resulted in similar fertilization and only minor changes in embryo quality. [ABSTRACT FROM AUTHOR]

Objectives were to develop a timed artificial insemination (TAI) resynchronization program to improve pregnancy per AI and to evaluate responses of circulating progesterone and pregnancy-associated glycoproteins in lactating cows. Cows (n = 1,578) were presynchronized with 2 injections of PGF2α, given 14 d apart starting on d 45 ± 3 postpartum, followed by Ovsynch [2 injections of GnRH 7 d before and 56 h after injection of PGF2α, TAI 16 h after second injection (d 0)]. The Resynch-treated cows received an intravaginal progesterone insert from d 18 to 25, GnRH on d 25, and pregnancy diagnosis on d 32, and nonpregnant cows received PGF2α., GnRH 56 h later, and TAI 16 h later (d 35). The control cows were diagnosed for pregnancy on d 32 and nonpregnant cows received GnRH, PGF2α 39 d after TAI, GnRH 56 h later, and TAI 16 h later (d 42). Pregnancy was reconfirmed on d 60 after AI. Ovarian structures were examined in a subset of cows at the time of GnRH and PGF2α injections. Blood samples for analyses of progesterone and pregnancy-associated glycoproteins were collected every 2 d from d 18 to 30 in 100 cows, and collection continued weekly to d 60 for pregnant cows (n = 43). Preenrollment pregnancies per AI on d 32 did not differ for cows subsequently treated as Resynch (45.8%, n = 814) and control (45.9%, n = 764), and pregnancy losses on d 60 were 6.7 and 4.0%, respectively. Resynchronized service pregnancy per AI (36%, n = 441; 39.5%, n = 412) and pregnancy losses (6.3 and 6.7%) did not differ for Resynch and control treatments, respectively. Days open for pregnant cows after 2 TAI were less for the Resynch treatment than for the control treatment (96.2 ± 0.82 vs. 99.5 ± 0.83 d). Cows in the Resynch treatment had more large follicles at the time of GnRH. The number of corpora lutea did not differ between treatments at the time of PGF2α. Plasma progesterone for pregnant cows was greater for Resynch cows than for control cows (18–60 d; 6.6 vs. 5.3 ng/mL), and plasma concentrations of progesterone on d 18 were greater for pregnant cows than for nonpregnant cows (5.3 vs. 4.3 ng/mL). Plasma pregnancy-associated glycoproteins during pregnancy were lower for cows in the Resynch treatment compared with control cows on d 39 (2.8 vs. 4.1 ng/mL) and 46 (1.3 vs. 3.0 ng/mL). Cows pregnant on d 32 that lost pregnancy by d 60 (n = 7) had lower plasma concentrations of pregnancy-associated glycoproteins on d 30 than cows that maintained pregnancy (n = 36; 2.9 vs. 5.0 ng/mL). Pregnancy-associated glycoproteins on d 30 (>0.33 ng/mL) were predictive of a positive d 32 pregnancy diagnosis (sensitivity = 100%; specificity = 90.6%). In conclusion, Resynch and control protocols had comparable pregnancy per AI for first and second TAI services, but pregnancy occurred 3.2 d earlier in the Resynch group because inseminations in the Resynch treatment began 7 d before those in the control treatment. Administration of an intravaginal progesterone insert, or GnRH, or both increased progesterone during pregnancy. Dynamics of pregnancy-associated glycoproteins were indicative of pregnancy status and pregnancy loss. [ABSTRACT FROM AUTHOR]

Contents Objectives were to evaluate effects of feeding a calcium salt rich in linoleic and trans-octadecenoic acids (LTFA) on synthesis of prostaglandin F2α based on its metabolite (PGFM), uterine involution and pregnancy rates in lactating dairy cows. Five hundred and eleven Holstein cows were blocked according to parity, body condition score and milk yield in the previous lactation. Primiparous and multiparous cows were randomly assigned to one of the two treatments consisting of calcium salt (2% diet dry matter) of either palm oil (PO) or LTFA from 25 days prepartum to 80 days of lactation. Cows were time-inseminated at 70 ± 3 days postpartum. Feeding LTFA tended (p = 0.08) to decrease the incidence of puerperal metritis (15.1% vs 8.8%). Primiparous cows supplemented with LTFA showed larger increase in plasma PGFM concentration at day 1 postpartum (17018 vs 6897 pm). Pregnancy rate after first insemination tended (p = 0.07) to be greater at 27 days after insemination (37.9% vs 28.6%), and was greater (p = 0.05) at 41 days after insemination (35.5% vs 25.8%) for cows fed LTFA compared with PO. These results indicate that unsaturated fatty acids fed in a rumen inert form have the potential to modulate reproductive events and improve pregnancy rates in lactating dairy cows. [ABSTRACT FROM AUTHOR]

The objectives were to evaluate the effects of source of fatty acids (FA) on embryo quality of dairy cows. A total of 154 Holstein cows were assigned randomly to 1 of 2 sources of FA supplemented at 2% Of the dietary dry matter as calcium salts of either palm oil (PO) or linoleic and trans-octaclecenojc acids (LTFA) from 25 d prepartum to 80 d in milk (DIM). Cows were presynchronized beginning at 30 ± 3 DIM and then subjected to the Ovsynch protocol beginning on d 39 ± 3 postpartum. Timed artificial insemination was performed 12 h after the final GnRH of the Ovsynch protocol with semen from a singlesire of proven fertility. The uteri of cows were nonsurgically flushed at 5 d after artificial insemination for collection of embryos-oocytes. Ovaries were examined by ultrasonography throughout the synchronization protocol. Blood was sampled and plasma was analyzed for concentrations of metabolites and hormones. The body condition score and yields of milk and milk components were measured throughout the first 90 DIM. Treatment did not affect concentrations of nonesterified FA, β-hydroxybutyrate, glucose, and progesterone in plasma. Body condition was similar between treatments. Milk production was similar between treatments, but concentrations of fat in milk and yields of fat and 3.5% fat-corrected milk decreased in cows fed LTFA, whereas concentration of true protein increased. Source of dietary FA did not influence ovulatory responses, diameter of the ovulatory follicle, and diameter of the corpus luteum during synchronization. Embryo-oocyte recovery relative to the number of corpora lutea did not differ between treatments. Fertilization tended to increase in cows fed LTFA compared with cows fed PO. Feeding LTFA. improved the proportion of excellent-, good-, and fair- quality embryos, and embryos from cows fed LTFA had a greater number of blastomeres than embryos from cows fed PO. Feeding a more unsaturated source of FA improved fertilization and embryo development in lactating dairy cows, despite similar indicators of metabolic status. [ABSTRACT FROM AUTHOR]

A total of 799 Holstein cows from 3 herds were randomly assigned at 37 ± 3 d in milk (DIM) to timed artificial insemination (AI) or insemination at detected estrus. Cows were presynchronized with injections of PGF2α at 37 and 51 DIM. At 65 DIM, cows received an injection of GnRH, followed 7 d later by PGF2α. Cows in the estrus-detected group were inseminated after being observed in estrus during the 7 d after the last PGF2α. Cows in the timed AI group received an injection of 1 mg of estradiol cypionate (ECP) 24 h after the last PGF2α. If detected in estrus ≤24 h after ECP, cows were inseminated then or at a fixed time 48 h after ECP. Pregnancy was diagnosed by ultrasonography at 30 d and by palpation at 44 and 58 d after AI. Plasma progesterone was measured in 4 samples per cow collected on days of 1) second PGF2α, 2) GnRH, 3) third PGF2α, and 4) 48 h after third PGF2α. Cows were classified as cyclic or anovulatory based on progesterone concentrations in samples 1 and 2. Similarly, cows were classified according to progesterone concentrations in samples 2, 3, and 4 (H = ≥1 ng/mL; L = <1 ng/mL), resulting in 8 combinations (LLL, LHL, LLH, LHH, HHH, HHL, HLH, and HLL). Conception rates and pregnancy rates were higher for cows in the timed AI group than in the estrus-detected group at 30, 44, and 58 d (e.g., at 58 d, pregnancy rates were 42.2% for multiparous cows or 34.4% for primiparous cows in the group receiving ECP and timed AI compared with only 20.8 or 18.8% for respective parity subgroups for the treatment group inseminated only at detected estrus). Pregnancy losses were 11.5% from 30 to 58 d and did not differ between treatments. Cyclic cows within both treatments had higher estrous responses, conception rates, and pregnancy rates. Cows that responded to presynchronization and to luteolysis (HHL) had the highest conception... [ABSTRACT FROM AUTHOR]

Despite a growing interest in microalgae and cyanobacteria as potential sources of nutrients in aquafeeds, little information is presently available on their nutritive value for carnivorous fish species. The aim of this study was to evaluate chemical composition and nutrient digestibility of a panel of microalgae and cyanobacteria dried biomasses (MACB), using rainbow trout (Oncorhynchus mykiss W.) as a fish model. Nine test diets were obtained by mixing 80 parts of a reference diet, added with 20 g/kg of acid insoluble ash as an indigestible marker, to 20 parts of each of the following dried whole-cell biomass: Arthrospira platensis , Nostoc sphaeroides , two strains of Chlorella sorokiniana , Nannochloropsis oceanica , Tisochrysis lutea , Phaeodactylum tricornutum , Porphyridium purpureum and Tetraselmis suecica. The digestibility measurements were conducted with rainbow trout (52.4 ± 1.5 g) kept in six tank units each including three 60-L vessels singularly stocked with 12 fish and fitted with a settling column for faecal recovery. Per each diet, faeces were collected over three independent 10-day periods. Apparent digestibility coefficients (ADCs) of dry matter, crude protein (CP), organic matter and gross energy (GE) of single MACB were calculated by difference relative to those of the reference diet. The MACBs had heterogeneous chemical composition (CP, from 20 to 69%; Lipid, 5–27%; GE, 12.5‐–22.6 MJ/kg dry matter basis) reflecting their overall biodiversity. Most of them can be considered as virtually good sources of minerals and trace elements and exhibit an essential amino acid profile comparable or even better than that of soybean meal commonly used in fish feeds with P. purpureum showing the best protein profile. The digestibility results obtained with rainbow trout allowed ranking the MACBs into two major groups. A first one, including C. sorokiniana , N. oceanica and T. suecica, resulted in markedly lower (P < 0.05) crude protein and energy ADC (64–73%; 51–59%, respectively) compared to a second group including P. purpureum , T. lutea and cyanobacteria (CP-ADC, 83–88%; GE-ADC, 74–90%) while P. tricornutum resulted in intermediate values. Overall, the present study confirms the consistently reported role of cell-wall structure/composition in affecting accessibility of nutrients to digestive enzyme. Based on the overall outcomes, only T. lutea and cyanobacteria actually meet the requirements for being used as protein sources in aquafeeds provided their mass production becomes more feasible and cost-effective, hence attractive for the feed-mill industry in the near future. • Nutritive value of dried microalgae-cyanobacteria for rainbow trout was estimated. • Chemical composition reflected their biodiversity and culture conditions. • Nutrient and energy digestibility correlates with cell wall structure. • Most of them are good sources of trace elements. • Cyanobacteria and T. lutea are potential protein sources in fish diets. [ABSTRACT FROM AUTHOR]

After classification and identification of the plant, the alcoholic extract of Cachrys libanotis L. was analysed in order to identify the phototoxic agents. The substances responsible for photodermatitis were found to be 4 furocoumarins, of which 3 have been clearly identified, namely 5-methoxy-, 8-methoxy- and 5.8-dimethoxypsoralen. The structure of a 4th compound was not completely defined. [ABSTRACT FROM AUTHOR]

Objectives were to determine the effect of source of supplemental Se on postpartum health, immune responses and Se status of periparturient Holstein cows. Treatments were sodium selenite (SS, n=291) or Se yeast (SY, Sel-Plex®, n=286) supplemented at 0.3 ppm from d 25 prior to calving to 80 d in milk. Health of dairy cows was monitored daily in the first 80 d in milk, and rectal temperature was taken for the first 10 d postpartum. A subset of 15 primiparous and 24 multiparous in the SS group and 10 primiparous and 26 multiparous in the SeY group was used to evaluate cellular and humoral immune responses. A colostrum sample at the first milking after calving was analyzed for total IgG concentrations. Concentrations of Se in plasma were determined at -45, 0, 21, 42 and 60 d relative to calving. Glutathione peroxidase activity in plasma, neutrophil phagocytic activity and its oxidative metabolism were determined on days 0 and 42 postpartum. Each animal received an i.m. injection of 1 mg of ovalbumin at -45, -25 and 0 d relative to calving. Anti-ovalbumin IgG concentrations in serum were analyzed at every injection and at 21 and 42 d postpartum. Concentration of Se in plasma was similar (P = 0.38) for SY and SS throughout the study (0.107 vs 0.101 μg/mL). Glutathione peroxidase activity in plasma was not affected (P = 0.70) by source of Se. Concentration of IgG in colostrum was similar (P = 0.24) for SY and SS (60.9 vs 71.0 g/dL). Phagocytic and killing activities of neutrophils were influenced (P <0.01) by days postpartum, but not (P > 0.10) by source of Se. Similarly, the ability of neutrophils to reduce nitroblue tetrazolium was not (P > 0.10) influenced by source of Se in stimulated and nonstimulated neutrophils. Incidence of retained placenta (SY=9.4 vs SS=8.6%), fever (SY=47.0 vs SS=44.7%), clinical ketosis (SY=22.1 vs SS=22.3%), displacement of abomasum (SY=2.5 vs SS=3.8%), and mastitis (SY=27.3 vs SS=25.1%) were not affected (P > 0.10) by source of supplemental Se, but a greater (P < 0.01) proportion of cows fed SY experienced acute metritis (21.3 vs 13.4%). Source of Se did not influence health or immunological status of periparturient dairy cows. [ABSTRACT FROM AUTHOR]

Abstract Sperm density and performance of wild and farmed male European eels were evaluated to investigate the effect of maintenance in captivity on ejaculate quality. Hormonal stimulation (with human chorionic gonadotropin) lasted for 17 weeks. Different origins of the male European eels partially influenced the quality of the ejaculates. Indeed, wild animals (i.e., collected at a natural site) had greater sperm longevity during the hormonal stimulation, whereas there was no significant effect of the origin on sperm density, spermatocrit, the percentage of motile sperm, and plasma testosterone concentrations. The different origins of the males also affected fatty acid sperm content, with greater unsaturated fatty acid and omega-6 concentrations in wild eels and lesser concentrations of saturated fatty acids and omega-3 fatty acids in farmed eels. Regarding sperm quality of European eels, this is the first study that takes into account the effect of different origins of stimulated males (wild-caught compared with farmed) on sperm quality, and these findings may help to improve the production of high-quality gametes in this endangered species. [ABSTRACT FROM AUTHOR]

Objectives were to determine the effect of source of supplemental Se on embryo quality and uterine health of dairy cows. Holstein cows, 135, were assigned to Se yeast (SY, Sel-Plex®) or sodium selenite (SS) supplemented at 0.3 ppm from 25 d prior to calving to 80 d in milk (DIM). Cows were fed as group in 4 pens/treatment, 2 prepartum and 2 postpartum pens. Health of cows was evaluated daily and rectal temperature taken in the first 10 DIM. Uterine cytology was performed at 30 ± 3 DIM by flushing the previously gravidic horn with 20 mL of saline. The collected material was then classified according to visual appearance, and evaluated for concentration of leukocytes and proportion of neutrophils. Cows were presynchronized at 33 ± 3 DIM (d 33 GnRH + CIDR insert, d 40 PGF2a + CIDR removal), and subjected to the Ovsynch protocol 2 d after presynchronization (d 42 GnRH, d 49 PGF2a, d 51 GnRH). Cows were time inseminated 12 h after the final GnRH of the Ovsynch with semen from a single sire. Uteri of cows were flushed 6 d after AI and collected structures were evaluated. Ovarian responses were evaluated by ultrasonography, and blood was analyzed for progesterone throughout the study and for glutathione peroxidase (GPx) activity at the day of embryo flushing. Incidence retained placenta (SY = 2.9 vs SS = 10.8 %), acute postpartum metritis (SY = 17.4 vs SS = 25.7 %), fever (SY = 21.7 vs SS = 29.7 %), mastitis (SY = 26.1 vs SS = 35.2 %), ketosis (SY = 11.6 vs SS = 12.2 %), and clinical endometritis (SY = 14.7 vs SS = 14.3 %) did not differ (P > 0.10) between treatments. Plasma GPx activity was similar (P = 0.35) for SY and SS, and averaged 571.18 nMol/mL/min. Fertilization rate did not differ (P = 0.22) between SY and SS (73.2 vs 84.1 %). Embryos classified as excellent and good as a percentage of fertilized (SY = 73.3 vs SS = 59.4 %) and total structures (SY = 53.6 vs SS = 50.0 %) were similar (P > 0.10) between treatments. Replacing a source of inorganic Se with Se yeast did not improve uterine health or embryo quality in lactating dairy cows. [ABSTRACT FROM AUTHOR]

Five experimental diets (CTRL, 50FMFO, 50FMFO-50MIC, 0FMFO-50MIC, 0FMFO-100MIC) were formulated to replace wild-caught fishmeal (FM), wild-caught fish oil (FO) and soy protein using fisheries, aquaculture by-products (BP) and microalgae (MIC). Fifty European sea bass juveniles were distributed in 15 tanks (initial body weight 46.66 ± 0.04 g) and reared in a recirculating aquaculture system for 88 days. Temperature, salinity, oxygen and photoperiod were kept constant throughout the experiment (22 ± 0.5 °C, 25 g L−1 and 8.0 ± 1.0 mg L−1, 12:12 light/dark, respectively). Growth, feed intake (FI), proximal composition, nutritional index, apparent digestibility, somatometric indexes, blood plasma biochemistry and digestive enzyme activity were evaluated. Also, gut microbiota composition was assessed through next-generation sequencing. Results showed that growth performance and feed digestibility were not affected by FM, FO and soy replacement using BP and MIC. Dietary replacement of 100% FM and FO with circular substitutes and 50% replacement of soymeal with microalgae increased the activity of alkaline phosphatase and chymotrypsin. Moreover, the inclusion of BP and MIC had positive effects on the gut microbiota richness and abundance. In conclusion, the utilization of BP and MIC represents a valuable alternative to FM and FO as well as soy protein in feed for European sea bass juveniles. • Integration of FM and FO from trimming, with microalgae did not affect overall growth and feed efficiency. • Microalgae as a protein source promotes digestive enzyme activity. • Microalgae positively impact microbiota richness and abundance. [ABSTRACT FROM AUTHOR]

The objectives of this study were to describe herdlevel reproductive outcomes and their associations with the prevalence of lameness, hock injuries and knee injuries in freestall dairy herds in the northeastern United States. Five reproductive outcomes (calving to conception interval, CCI; calving interval, CI; conception risk at the first artificial insemination, CR1; insemination rate, IR; and pregnancy rate, PR) were measured from Dairy Comp 305 (Valley Agricultural Software, Tulare, CA) for a 12-mo period for all multiparous cows in each of the 53 herds assessed. The prevalence of lameness, hock injuries, and knee injuries was assessed in 1 highproducing group. The means (± standard deviation) for the 5 reproductive outcomes were as follows: CCI = 128 ± 10 d, CI = 404 ± 10 d, CR1 = 36 ± 5%, IR = 60 ± 7%, and PR = 20 ± 3%. The average prevalence of clinical lameness, hock injuries, and knee injuries were 45 ± 20%, 58 ± 31%, and 16 ± 15%, respectively. Univariable associations between the reproductive outcomes and the prevalence of lameness and leg injuries were tested and significant predictors were submitted to a model that controlled for the confounding effects of herd size, 305-d mature equivalent milk production of the high-producing group, and use of deep bedding. A higher prevalence of lameness was associated with poorer reproductive performance, although the relationships were weak: herds with a higher prevalence of lameness had longer average CCI (slope estimate = 0.16 ± 0.07; R² = 0.09) and CI (slope estimate = 0.14 ± 0.07; R² = 0.07). These results indicate that management to reduce lameness may improve reproductive performance. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the effects of method of presynchronization and source of supplemental Se on uterine health and reproductive performance of lactating dairy cows. Holstein cows (n = 512) were assigned randomly to 2 methods of presynchronization, Presynch (2 PGF2α given 14 d apart) or CIDR-PS (controlled internal drug releasing inserted for 7 d with an injection of PGF2α at removal) and 2 sources of Se, sodium selenite (SS) or selenized yeast (SY) supplemented at 0.3 mg/kg from 25 d before calving to 80 d in milk (DIM) arranged in a 2 x 2 factorial. Cows were inseminated following the Ovsynch protocol (d 0 GnRH, d 7 PGF2α, d 9 GnRH, timed artificial insemination (AI) 12 h after the final GnRH) starting at 12 and 3 d after Presynch and CIDR-PS, respectively. Cows were diagnosed for pregnancy at 28, 42, and 56 d after AI. Source of Se did not influence uterine health and resumption of cyclicity, but fewer CIDR-PS than Presynch cows were cyclic at the beginning of the Ovsynch, although differences in the proportion cyclic may have been caused by the timing when corpus luteum evaluations were performed in the different presynchronization treatments. Ovulatory responses were not influenced by source of Se. However, the CIDR-PS increased ovulation to the first GnRH, double ovulation to the final GnRH, and size of ovulatory follicle at PGF2α and final GnRH of the Ovsynch, but did not influence ovulation at the final GnRH of the Ovsynch. Concentrations of estradiol during the Ovsynch increased with follicle diameter and were greater for cows receiving CIDR-PS than Presynch, but they were not influenced by source of Se. Pregnancy per AI on d 28 (32.7%), 42 (28.5%), and 56 (25.9%) after AI, and pregnancy loss (20.5%) from 28 to 56 d were not influenced by source of Se or method of presynchronization. Although cows receiving CIDR-PS had an increased incidence of ovulation to the first GnRH (73.2 vs. 57.8%) and double ovulation to the final GnRH of the Ovsynch (18.7 vs. 9.0%), both of which enhanced pregnancy, the CIDRPS protocol did not improve pregnancy per AI or reduce pregnancy loss compared with presynchronization with PGF2α alone. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the effect of 3 methods of resynchronization of estrus and ovulation for lactating dairy cows of unknown pregnancy status on conception rate and time to pregnancy. Holstein cows (n = 495) were randomly assigned to 1 of 3 treatments: 1) control (n = 167), resynchronization with a timed AI protocol upon diagnosis of nonpregnancy on d 31 after preenrollment AI (PAD; 2) CIDR-G (n = 159), use of an intravaginal progesterone insert from d 14 to 21 after AI, with AI at estrus from d 21 to 24 and initiation of a timed AI protocol on d 24 after AI in cows not reinseminated; 3) CIDR-G + ECP (n = 169), the same treatment as CIDR-G but with an injection of 1 mg of estradiol cypionate at the time of progesterone insert removal. Cows were continuously reenrolled in the same treatment until diagnosed as pregnant, which resulted in a total of 1,148 M (495 PAI and 653 resynchronized AI; RAI). Blood was collected from 1,001 cows on d 14, 21, and 24 after each AI for analysis of progesterone, and ovaries were scanned on d 21, 24, and 31 after AI. The presence of an active corpus luteum was presumed based on progesterone >1 ng/mL. Pregnancy was diagnosed by ultrasonography on d 31 and 61 after AI. The presence of an active corpus luteum and the incidence of luteolysis were similar for all treatments from d 14 to 24; however, luteolysis increased in the CIDR-G + ECP treatment from d 21 to 24. Conception rates for the PAI and all AI were similar on d 31 and 61 after insemination. Conception rates at 31 and 61 d after the RAI were also similar among treatments. Overall pregnancy loss for the PAI, RAI, and all AI were similar for all treatments. The accuracy of estrous detection, based on progesterone concentration within 2 d of detection of estrus, was similar for all treatments for the RAI and averaged 95.3%. The estrus-detection rate (EDR) decreased for the CIDR-G and CIDR-G + ECP treatments from d 14 to 21, but increased from d 21 to 24 compared with control cows; however, the EDR was smaller for cows in the CIDR-G treatment during the entire resynchronization period compared with those in the CIDR-G + ECP and control groups. The reinsemination interval was reduced in cows receiving the CIDR-G + ECP treatment compared with control cows because of increased EDR after removal of the intravaginal insert; however, the interval from study enrollment to pregnancy was not different among treatments. These results indicate that the reproductive performance of dairy cows did not differ among the 3 resynchronization treatments evaluated. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the effects of an intravaginal insert containing progesterone (CIDR, controlled internal drug releasing) administered in presynchronization and resynchronization protocols on cyclicity, detection of estrus, pregnancy rate, and pregnancy loss to first AI; reinsemination patterns; and pregnancy rates to second postpartum AI before and after the time of first-service pregnancy diagnosis in dairy cows. Holstein cows (n = 1,052) were blocked by parity and BCS at 3 ± 3 d in milk (study d 0 = day of calving) and assigned randomly to 1 of 3 presynchronization treatments. During the presynchronization programs, all cows received 2 injections of PGF2α, on study d 35 and 49. Cows enrolled in the control presynchronization treatment received M after detected estrus from study d 49 to 62. Cows enrolled in the CIDR estrus-detection (CED) presynchronization treatment received a CIDR insert from study d 42 to 49 and AI on detection of estrus from d 49 to 62. Cows enrolled in the CIDR timed AI (CTAI) presynchronization treatment received the same treatment as CED, but were subjected to timed AI on study d 72 after the Ovsynch (GnRH, 7 d PGF2α, 2 d GnRH, 24 h timed AI) protocol. The control and CED cows not inseminated by study d 62 were enrolled in the Ovsynch protocol on the same day and received timed AI on study d 72. After first AI, cows were assigned to no resynchronization (RCON) or resynchronization with a CIDR insert (RCIDR) between 14 and 21 d after AI. Blood samples collected on study d 35, 49, and 62 were analyzed for concentrations of progesterone and cows were classified as anestrous when progesterone was <1.0 ng/mL in the first 2 samples. On study d 62, anestrous cows with progesterone ≥1.0 ng/mL were classified as having resumed cyclicity. Pregnancy was diagnosed at 31 and 60 d after first AI and at 42 d after second AI. A greater proportion of anestrous cows in CED and CTAI became cyclic by d 62 postpartum than control cows. Resynchronization with the CIDR insert increased the pregnancy rate at 31 d after first AI in CED and CTAI, and at 60 d after AI in all cows because of reduced pregnancy loss. These results indicate that presynchronization with the CIDR insert increased induction of cyclicity in anestrous cows and that resynchronization with the CIDR insert did not affect the reinsemination rate but did reduce pregnancy loss and increased the pregnancy rate at 60 d after first AI. [ABSTRACT FROM AUTHOR]

The objective was to determine the effects of bovine somatotropin (bST) and two artificial insemination (AI) protocols on reproductive performance of Holstein cows. Lactating cows (n = 840) were assigned at 37 d in milk (DIM) to one of four treatments in a 2 x 2 factorial arrangement. Treatments consisted of either bST (500 mg/14 d) starting at 63 ± 3 DIM or no bST (control), with cows either submitted for timed AI following a synchronized ovulation (Ovsynch) protocol or assigned to receive AI based on estrus detection (ED). Two injections of PGF2α at 37 ± 3 and 51 ± 3 DIM were used to presynchronize estrous cycles. Cows then received an injection of GnRH at 63 ± 3 DIM, followed 7.5 d later by PGF2α. Cows assigned to ED treatments were inseminated after observed estrus during a 7-d period. Cows in Ovsynch treatments received a second GnRH injection 48 h after the last PGF2α, and received timed AI 16 to 18 h later. Pregnancy was diagnosed by ultrasound at 31 d after AI and confirmed 14 d later. Frequency of anovulation (18.5%) at 63 DIM was similar across treatments, but proportions of anovulatory cows decreased quadratically as body condition at 70 DIM increased from 2.25 to 3.75. Estrus detection rate after PGF2α tended to be lower in multiparous cows receiving bST, and bST reduced returns to estrus in nonpregnant cows. Conception rates were higher in cows receiving AI after ED and bST improved conception rates to first AI in cyclic cows by reducing embryonic mortality. Pregnancy loss was similar for cows inseminated following ED or the Ovsynch protocol. There was a positive impact of bST on fertility of cyclic cows inseminated at fixed time or at detected estrus, but effective resynchronization protocols are needed to optimize reinsemination of nonpregnant bST-treated cows. [ABSTRACT FROM AUTHOR]

This experiment evaluated the impacts of estrus expression and intensity, estimated by physical activity during a timed-AI protocol, on reproductive performance of Bos indicus-influenced beef cows. A total of 290 lactating, primiparous, and multiparous nonpregnant Nelore × Angus cows received a 2 mg injection of estradiol benzoate and an intravaginal progesterone (P4) releasing device (CIDR) on d -11, a 12.5 mg injection of PGF2α on d -4, CIDR removal in addition to 0.6 mg injection of estradiol cypionate and 300 IU injection of eCG on d -2, and timed-AI on d 0. Cows were fitted with a pedometer behind their left shoulder on d -4. An estrus detection patch was attached to the tail-head of each cow on d -2. Pedometer results were recorded on d -2 and 0. Estrus expression was defined as removal of >50% of the rub-off coating from the patch on d 0. Net physical activity during estrus was calculated by subtracting total steps from d -4 to -2 (nonestrus basal activity) from total steps from d -2 to 0 (proestrus + estrus period) of each cow. Cows that did not express estrus were classified as NOESTR. Cows that expressed estrus were ranked by net physical activity; those above the median were classified as HIESTR and the remaining cows as LWESTR. Ovarian ultrasonography was performed on d 0 and 7. Blood was collected on d 0, 7, 20, and 30. Pregnancy status was verified by ultrasonography on d 30. Only data from cows responsive to the estrus synchronization protocol were utilized (NOESTR, n = 59; LWESTR, n = 100; HIESTR, n = 98). Diameter of dominant follicle on d 0, corpus luteum volume on d 7, and plasma P4 concentrations on d 7 were greater (P ≤ 0.05) in HIESTR vs. LWESTR and NOESTR and also greater (P ≤ 0.05) for LWESTR vs. NOESTR. Plasma P4 concentrations on d 0 were greater (P < 0.01) in NOESTR vs. HIESTR and LWESTR and similar (P = 0.93) between HIESTR and LWESTR. Whole blood mRNA expression of myxovirus resistance 2 on d 20 was greater (P ≤ 0.05) in HIESTR vs. LWESTR and NOESTR, and similar (P = 0.72) between LWESTR and NOESTR. Pregnancy rates were less (P ≤ 0.04) in NOESTR vs. HIESTR and LWESTR (52.4%, 68.9%, and 73.5%, SEM = 7.2), and similar (P = 0.57) between HIESTR and LWESTR. Hence, expression of estrus during a timed-AI protocol improved ovarian dynamics and pregnancy success, whereas estrus intensity modulated key biological markers associated with fertility but not pregnancy rates in B. indicus-influenced cows beef cows. [ABSTRACT FROM AUTHOR]

Objectives were to quantify lying behavior (LB) during an estradiol and progesterone-based synchronization protocol, to assess risk factors for ovulation, pregnancy per AI (P/AI), and degree of behavioral change at estrus, and to investigate the associations between estrus LB and walking activity. Holstein cows (43.6 ± 11.0 kg of milk/d) were fitted with leg-mounted accelerometers. Total lying time/d (L_time), bout frequency (bout_N), average lying bout duration, and relative increase in walking activity (ACT%) were evaluated for 1,411 timed artificial insemination events. The day with lowest L_time or bout_N among d −2, −1, and 0 (day of timed artificial insemination) determined the day of behavioral estrus. The variables L_time% and bout_N% represent relative ratios between lowest L_time and baseline (d −7), L_time, and lowest bout_N, and baseline (d −7) bout_N, respectively {e.g., (lowest L_time/baseline L_time) × 100]. Correlation coefficients between L_time% and bout_N% and ACT% were −0.38 and −0.31, respectively. Estrus LB change was considered large if <75% of baseline and small if ≥75% of baseline for both L_time% and bout_N%; average lying bout duration did not change with estrus. Lowest L_time% and bout_N% corresponded to, respectively, 65 ± 21% (mean ± standard deviation; 447 ± 157 min/d) and 65 ± 24% (8.5 ± 4.0 bouts/d) of baseline. The change in L_time% at estrus was smaller when cows had milk yield above average; the change in bout_N% was smaller among multiparous cows and for estrus occurring in the colder season. Likelihood of ovulation was greater when there was larger change in L_time% [odds ratio = 4.9; ovulation rate = 93 (large change) and 76% (small change)], as well as when a corpus luteum was present at start of protocol (odds ratio = 3.6; in the model with L_time%). Likelihood of pregnancy at d 32 was 1.6 times greater for estrus with large change in LB [L_time% or bout_N%; P/AI = 34% (large change in L_time%) and 26% (small change in L_time%)]. Among estrus events with ACT% ≥300% (high intensity), classification by small or large L_time% did not influence P/AI at 32 d. The magnitude of LB change at estrus and its association with fertility suggest potential application toward improved use of activity monitors (e.g., increased estrus detection, fertility prediction). The contribution of LB to accuracy of estrus detection when physical activity is known remains to be addressed. The relationship between intensity of estrus expression and fertility requires further investigations of its physiological rationale and on-farm applications. [ABSTRACT FROM AUTHOR]

This study compared vaginal temperature, physiologic, and productive parameters in lactating dairy cows supplemented or not with Omnigen-AF (Phibro Animal Health, Teaneck, NJ) during the summer months in a tropical environment. Thirty-two lactating, primiparous (n = 16) and multiparous (n = 16) pregnant Holstein x Gir cows were ranked by parity, days in milk, body weight, and body condition score (BCS), and assigned to receive (SUPP; n = 16) or not (CON; n = 16) Omnigen-AF (Phibro Animal Health, Teaneck, NJ) at 56 g/cow daily (as-fed basis). During the experimental period (d -6 to 56), cows were maintained in a single drylot pen with ad libitum access to water and a total mixed ration, and milked twice daily. Cows received Omnigen-AF mixed with 200 g of corn (as-fed basis) after the daily morning milking through self-locking head gates, whereas CON cows concurrently received 56 g of kaolin mixed with 200 g of corn. For feed intake evaluation, cows from both treatments were randomly divided in 4 groups of 8 cows each, and allocated to 8 individual feeding stations for 3 d. Intake was evaluated 4 times per group from d 1 to 56. From d -6 to 0, d 15 to 28, and d 43 to 56, cow vaginal temperature was recorded hourly. Environmental temperature-humidity index (THI) was also recorded hourly from d 15 to 28 and d 43 to 56. Cows were evaluated for body weight and BCS on d -6 and 56, individual milk production was recorded daily from d -6 to 56, and milk samples were collected on d -6, 0, 7, 14, 21, 28, 35, 42, 49, and 56 for analyses of somatic cell count and milk components. Blood samples were collected on d -6, -3, 0, 9, 15, 18, 21, 24, 27, 36, 45, 48, 51, 54, and 56. Results from samples or observations collected from d -6 to 0 were included as an independent covariate in each respective analysis. Environmental THI was 74.2 ± 0.5 and cows were exposed to THI >68 for 633 h within a total of 672 h of evaluation. Cows assigned to CON had greater vaginal temperature on d 28, 43, 45, and from d 48 to 55 (by 0.38 to 0.52%), as well as greater mean somatic cell count (by 97%) and serum haptoglobin concentrations (by 89%) compared with SUPP cows. Cows assigned to SUPP had greater mean dry matter intake (by 7%), BCS on d 56 (by 11%), and mean serum insulin concentrations (by 35%) compared with CON cows. Hence, SUPP ameliorated hyperthermia, improved nutritional status, and modulated systemic and mammary gland immune parameters in lactating dairy cows exposed to heat stress conditions. [ABSTRACT FROM AUTHOR]

The objectives of this study were: (1) to describe the rumination and feeding behavior of freestall-housed Holstein dairy cows in the weeks around parturition, and (2) to determine the relationship between postpartum disease and precalving rumination and feeding behavior. Eighty cows were enrolled at approximately 2 wk (18 ± 7 d, mean ± standard deviation) before calving. Using automatic monitoring systems, rumination and feeding behavior were recorded continuously from 10 d before until 3 wk after calving. Postpartum health checks were performed each day, and metritis assessment was conducted 2 times/wk. Blood β-hydroxybutyrate was measured 3 times/week, and cows with ⩾1.2 mmol/L during the first 14 d postpartum were diagnosed as having subclinical ketosis. The final data set included 64 cows in 5 groups: healthy (n = 20), metritis (n = 18), subclinical ketosis (SCK; n = 9), metritis+SCK (n = 9), and >1 health problem and not included before (MULT, n = 8). We compared rumination and feeding data between healthy cows and the 4 categories of ill animals in each of 4 periods relative to calving: precalving (d −7 to −2), period 1 (d 3 to 8 postpartum), period 2 (d 9 to 14 postpartum), and period 3 (d 15 to 20 postpartum). Cows with SCK spent less time ruminating during the precalving period. Compared with healthy cows, those with SCK and metritis+SCK had lower dry matter intake during the precalving period and continued to eat less until d 14 and d 20 postpartum, respectively. Cows with metritis and MULT cows had lower dry matter intake during the first 2 wk postpartum. Precalving feeding time was lower for SCK, metritis+SCK, and MULT cows compared with healthy cows. The difference in feeding time between healthy and metritis+SCK cows had disappeared by period 2 and between all health categories except MULT by period 3. MULT cows visited the feed bins less often and were less often replaced at the feed bin throughout all 4 periods of the study. Automatic monitoring of intake and rumination showed promise for the detection of health problems after calving. We observed differences in precalving rumination and feeding behavior. Further research is necessary to better understand the onset of behavioral changes and the relationship between rumination and disease. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to compare hormonal, uterine, and conceptus factors associated with pregnancy establishment in Bos indicus beef cows supplemented or not with Ca salts of soybean oil (CSSO) for 21 d beginning after timed AI. One hundred lactating multiparous Nelore cows were allocated to 20 groups of 5 cows/group and timed inseminated on d 0 of the experiment. After AI, groups were randomly assigned to receive (as-fed basis) 100 g of protein–mineral mix + 100 g of ground corn per cow per day, in addition to 1) 100 g/cow daily of CSSO (n = 10) or 2) 100 g/cow daily of kaolin (CON; rumen-inert indigestible substance; n = 10). Groups were maintained in 4 Panicum maximum pastures (5 groups from the same treatment within each pasture) with ad libitum access to forage. Groups were segregated daily and individually offered treatments from d 0 to 21. Blood samples were collected and transrectal ultrasonography was performed to verify ovulation and corpus luteum (CL) volume immediately before AI (d 0) and on d 7 and 15. After ultrasonography on d 15, 60 cows (30 cows/treatment and 3 cows/group) diagnosed without the presence of a CL on d 0 but with a CL greater than 0.38 cm3 in volume on d 7 and 15 were assigned to conceptus collection via transcervical flushing with PBS followed by endometrial biopsy in the uterine horn ipsilateral to the CL. Additional blood samples were collected for whole-blood RNA extraction (d 20), and pregnancy status was verified by transrectal ultrasonography (d 30) in cows not assigned to conceptus collection. Cows receiving CSSO had greater (P ≤ 0.04) mean plasma linoleic acid concentration, plasma linoleic:linolenic acid ratio, plasma progesterone (P4) concentration, and CL volume during the experiment compared with CON cows. Moreover, CSSO supplementation increased (P ≤ 0.04) length and mRNA expression of prostaglandin E synthase and interferon-tau by the conceptus as well as blood mRNA expression of interferon-stimulated genes on d 20 in gestating cows. No treatment differences were detected (P ≥ 0.30) for endometrial mRNA expression of prostaglandin E synthase and cyclooxygenase-2. In summary, post-AI CSSO supplementation to B. indicus beef cows increased plasma concentration of linoleic acid and enhanced pregnancy establishment factors, which included CL development and plasma P4 concentration, conceptus growth, and mRNA expression of interferon-tau as well as blood mRNA expression of interferon-stimulated genes. [ABSTRACT FROM AUTHOR]

The relationship between plasma estradiol concentration at time of examination and prevalence of uterine disorders, agreement among methods, and associations of diagnosis with pregnancy hazard and milk yield was studied in 268 Holstein cows examined at 30 ± 3 (exam 1) and 44 ± 3 d in milk (DIM; exam 2). Purulent vaginal discharge was sampled using 2 methods: gloved hand and Metricheck (Simcro, Hamilton, New Zealand; PVD; score ≥3). Percentage of polymorphonuclear leukocytes was determined by endometrial cytology (CYTO; exam 1: ≥18%, exam 2: ≥10%); diameter of uterine horns (UTH; >20 mm), diameter of the inner layer of the cervix (CVX; >20.5 mm), presence of fluid in the uterine lumen (FL), and ovarian structures were evaluated by ultrasonography. A blood sample was collected at each exam for estradiol analysis. Prevalence at exams 1 and 2 was, respectively, 14.2 and 18.5% (PVD), 21.4 and 10.1% (FL), and 40.6 and 50.2% (CYTO). Prevalence of PVD at exam 1 was greater among cows with estradiol ≥2 pg/mL (19.4 vs. 8.2%). Agreement of all methods with CYTO was poor, the greatest being between CYTO and FL (exam 1; kappa = 0.19). Agreement between CYTO and PVD, and between CYTO and FL (exam 1; kappa = 0.15 and 0.35, respectively) was higher among cows with estradiol ≥2 pg/mL. Likelihood of PVD at exam 1 was greater if cows were positive for CVX [odds ratio (OR) = 3.0], FL (OR = 2.6) or had estradiol ≥2 pg/mL (OR = 2.7). Likelihood of CYTO increased with dystocia (OR = 2.3) and FL (OR = 2.5). Estradiol did not influence diagnosis at exam 2. Positive FL or CYTO at exam 1 was associated with reductions in milk yield of 59 to 180 kg by 45 DIM. Pregnancy hazard until 250 DIM was reduced by CYTO at exam 1 (hazard ratio = 0.74) and by PVD (hazard ratio = 0.68) at exam 2. However, FL and CYTO reduced pregnancy hazard only when estradiol was ≥2 pg/mL (exam 1), whereas PVD reduced pregnancy hazard when diagnosed at exam 2 with estradiol <2 pg/mL. Overall, agreement was poor and effects of positive diagnosis differed according to method and DIM at exam. Estradiol concentration influenced prevalence, agreement, likelihood of positive diagnosis, and its effects on days to pregnancy. [ABSTRACT FROM AUTHOR]

The objective of this series of studies was to investigate the effects of inflammatory diseases occurring before breeding on the developmental biology and reproductive responses in dairy cows. Data from 5 studies were used to investigate different questions associating health status before breeding and reproductive responses. Health information for all studies was composed of the incidence of retained fetal membranes, metritis, mastitis, lameness, and respiratory and digestive problems from parturition until the day of breeding. Retained placenta and metritis were grouped as uterine disease (UTD). Mastitis, lameness, digestive and respiratory problems were grouped as nonuterine diseases (NUTD). Study 1 evaluated the effect of disease before artificial insemination (AI), anovulation before synchronization of the estrous cycle, and low body condition score at AI on pregnancy per AI, as well as their potential interactions or additive effects. Study 2 investigated the effect of site of inflammation (UTD vs. NUTD) and time of occurrence relative to preantral or antral stages of ovulatory follicle development, and the effect of UTD and NUTD on fertility responses of cows bred by AI or by embryo transfer. Study 3 evaluated the effect of disease on fertilization and embryonic development to the morula stage. Study 4 evaluated the effect of disease on preimplantation conceptus development as well as secretion of IFN-τ and transcriptome. Study 5 investigated the effect of diseases before AI on the transcript expression of interferon-stimulated genes in peripheral blood leukocytes during peri-implantation stages of conceptus development after first AI postpartum. Altogether, these studies demonstrated that inflammatory disease before breeding reduced fertilization of oocytes and development to morula, and impaired early conceptus development to elongation stages and secretion of IFN-τ in the uterine lumen. Diseases caused inflammation-like changes in transcriptome of conceptus cells, increased risk of pregnancy loss, and reduced pregnancy or calving per breeding. Moreover, the effects on reproduction were independent of cyclic status before synchronization of the estrous cycle and body condition score at breeding, which all had additive negative effects on fertility of dairy cows. Occurrence of disease at preantral or at antral stages of ovulatory follicle development had similar detrimental effects on pregnancy results. The carryover effects of diseases on developmental biology might last longer than 4 mo. Reduced oocyte competence is a likely reason for carryover effects of diseases on developmental biology, but impaired uterine environment was also shown to be involved. [ABSTRACT FROM AUTHOR]

The objective of this study was to determine risk-factors affecting increase in physical activity during estrus and pregnancy per artificial insemination (P/AI) in lactating dairy cows. Cows were monitored continuously by 2 automated activity monitors [a collar-mounted accelerometer (HT; Heatime, SCR Engineers, Netanya, Israel) and a leg-mounted pedometer (BO; Boumatic Heat-seeker-TX, Boumatic Dairy Equipment, Madison, WI)]. When an increase in activity was detected, body condition score (BCS) and blood samples were collected, ovaries were scanned by ultrasonography, and, if the cow was eligible for breeding, artificial insemination was performed. Milk production and health-related data were recorded throughout the experimental period. Pregnancy diagnosis was performed at 42 ± 7 d of gestation. Data were analyzed using Pearson correlation, ANOVA, and logistic regression. A total of 1,099 true events of estrus from 318 lactating Holstein cows were recorded, averaging 3.46 ± 1.1 events per cow. Positive predictive value for estrus episodes detected by the HT and BO systems were 89.6 and 85.5%, respectively. Mean peak activity at estrus (PA) recorded by the HT system was 71.6 ± 20.7 index-value, and 334.3 ± 155.7% relative increase by the BO system. Compared with primiparous, multiparous cows expressed estrus with lower PA (69.3 ± 0.8 vs. 75.9 ± 1.1 index for HT; 323.9 ± 6.0 vs. 354.8 ± 8.48% for BO) and shorter duration (DU; 10.7 ± 0.2 vs. 12.0 ± 0.3 h); DU was measured by HT only. Lower BCS was associated with decreased PA measured by both systems, estrus DU, and P/AI. Peak activity was weakly correlated with milk production on the day of artificial insemination (r = -0.20); however, when categorized into quartiles, the highest-yield cows had lower PA and DU. Follicle diameter was not correlated with PA or DU, but cows with greater concentrations of estradiol had higher PA. Cows with greater PA in both systems had greater P/AI than those with lower PA (36.5 vs. 24.6% for HT, 33.5 vs. 21.4% for BO). In conclusion, measurements of estrus events captured by automated activity monitors are correlated with BCS, parity, and secondary behavior signs related to estrus. Surprisingly, estrus intensity and duration were only weakly correlated with milk production, preovulatory follicle diameter, and concentrations of estradiol at estrus. Cows that had measurements of high-intensity estrus were significantly more fertile than low-intensity estrus. [ABSTRACT FROM AUTHOR]

Two activity monitoring systems-Heatime (SCR Engineers Ltd., Netanya, Israel) and IceTag (IceRobotics Ltd., Edinburgh, UK)-were compared on their ability to detect and quantify estrus expression. Holstein heifers (n = 57) were fitted with Heatime (HT) and IceTag (IT) sensors from 12 mo of age until confirmation of pregnancy. Upon detection of high activity by HT, ovaries were scanned by ultrasound, a blood sample was collected for analysis of plasma estradiol, and signs of estrus (clear vaginal mucus, uterine muscle tone, visual mounting activity, standing to be mounted, or rump showing signs of repeated acceptance of mounts) were recorded. Because only estrus episodes detected by HT (n = 111) were further evaluated, only the positive predictive value was measured. Heifers were housed in groups of 24 in a freestall pen. Data were analyzed using Proc CORR and GLM of SAS (SAS Institute Inc., Cary, NC). The positive predictive value was 84.7% (94/111) for HT and 98.7% (74/75) for IT. Estrus duration was recorded by HT as 14.3 ± 4.1 h [mean ± standard deviation (SD)] and by IT as 15.0 ± 4.0 h; duration measurements were correlated (r = 0.60). The mean duration difference was 0.74 ± 3.52 h. Recordings of onset and end of estrus by IT were 3.5 ± 4.3 h and 2.9 ± 4.9 h earlier than those by HT. The overlap in duration was 9 h. Measurements of estrus intensity were correlated (r = 0.63). Peak activity was 77.3 ± 19.5 index value (approximately 7.7 SD from basal activity) on HT. The relative increase in activity measured by IT was 360 ± 170% baseline value. Measurements of intensity and duration from HT were correlated (r = 0.64) but those from IT were not (r = 0.13). Plasma estradiol concentration (11.2 ± 4.6 pg/mL) was not correlated with preovulatory follicle diameter or with duration or intensity of estrus. Diameter of preovulatory follicle (15.7 ± 2.6 mm) had no correlation with duration of estrus and was only weakly correlated with intensity measured by either system. Baseline steps/hour was negatively correlated with intensity from both sensors (r = -0.37 and -0.70 for HT and IT). Estrus episodes accompanied by 2 or 3 of the monitored signs of estrus had greater intensity and duration on HT but not on IT. Preovulatory follicle diameter and plasma estradiol concentration did not influence occurrence of estrus signs. Results indicate that both systems identified estrus precisely, with correlated characterization and similar timing. In contrast, relationships with plasma estradiol concentration and signs of estrus require further investigation. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the reproductive performance of dairy cows subjected to early (ER) or late (LR) resynchronization programs after nonpregnancy diagnoses based on either pregnancy-associated glycoproteins (PAG) ELISA or transrectal palpation, respectively. In addition, the accuracy of the PAG ELISA for early pregnancy diagnosis was assessed. Lactating Holstein cows were subjected to a Presynch-Ovsynch protocol with timed artificial insemination (AI) performed between 61 and 74 DIM. On the day of the first postpartum AI, 1,093 cows were blocked by parity and assigned randomly to treatments; however, because of attrition, 452 ER and 520 LR cows were considered for the statistical analyses. After the first postpartum AI, cows were observed daily for signs of estrus and inseminated on the same day of detected estrus. Cows from ER that were not reinseminated in estrus received the first GnRH injection of the Ovsynch protocol for resynchronization 2 d before pregnancy diagnosis. On d 28 after the previous AI (d 27 to 34), pregnancy status was determined by PAG ELISA, and nonpregnant cows continued on the Ovsynch protocol for reinsemination. Pregnant cows had pregnancy status reconfirmed on d 46 after AI (d 35 to 52) by transrectal palpation, and those that lost the pregnancies were resynchronized. Cows assigned to LR had pregnancy diagnosed by transrectal palpation on d 46 after AI (d 35 to 52) and nonpregnant cows were resynchronized with the Ovsynch protocol. Blood was sampled on d 28 after AI (d 27 to 34) from cows in both treatments that had not been reinseminated on estrus and again on d 46 after AI (d 35 to 52) for assessment of PAG ELISA to determine the accuracy of the test. Cows were subjected to treatments for 72 d after the first insemination. Pregnancy per AI (P/AI) at first post-partum timed AI did not differ between treatments and averaged 28.9%. The proportion of nonpregnant cows that were resynchronized and received timed AI was greater for ER than for LR (30.0 vs. 7.6%). Cows in ER had a shorter interval between inseminations when inseminated following spontaneous estrus (21.7 ± 1.1 vs. 27.8 ± 0.8 d) or after timed AI (35.3 ± 1.2 vs. 55.2 ± 1.4 d). Nevertheless, the ER did not affect the rate of pregnancy (adjusted hazard ratio = 1.23; 95% confidence interval = 0.94 to 1.61) or the median days postpartum to pregnancy (ER = 132 vs. LR = 140). A total of 2,129 PAG ELISA were evaluated. Overall, sensitivity, specificity, and positive and negative predictive values averaged 95.1, 89.0, 90.1, and 94.5%, respectively, and the accuracy was 92.1%. In conclusion, PAG ELISA for early diagnosis of pregnancy had acceptable accuracy, but early resynchronization after nonpregnancy diagnosis with PAG ELISA did not improve the rate of pregnancy or reduce days open in dairy cows continuously observed for estrus. [ABSTRACT FROM AUTHOR]

The objective of this experiment was to compare fatty acid (FA) concentrations in plasma and reproductive tissues as well as hormones and expression of genes associated with pregnancy establishment in beef cows supplemented or not with Ca salts of soybean oil (CSSO) beginning after timed AI. Ninety nonlactating muciparous Nelore (Bos indicus) cows were timed inseminated on d 0 of the experiment and divided into 18 groups of 5 cows/group. Groups were randomly assigned to receive (as-fed basis) 100 g of a protein-mineral mix plus 100 g of ground corn per cow daily in addition to 1) 100 g/cow daily of CSSO (n = 9) or 2) 100 g/cow daily of kaolin (CON; rumeninert indigestible substance; n = 9). All groups were maintained in a single Brachiaria brizanta pasture (24 ha) with ad libitum access to forage and water. However, groups were segregated daily and offered treatments individually at the working facility during the experimental period (d 0 to 18). Blood samples were collected and transrectal ultrasonography was performed to verify ovulation and estimate corpus luteum (CL) volume immediately before AI (d 0) and on d 7 and 18 of the experiment. On d 19,36 cows (18 cows/ treatment; 2 cows/group) diagnosed without the presence of a CL on d 0 but with a CL greater than 0.38 cm3 in volume on d 7 and 18 were slaughtered for collection of conceptus, uterine luminal flushing, and tissue samples from the CL and endometrium. Cows receiving CSSO had greater concentrations of linoleic and other ω-6 FA in plasma (P < 0.01), endometrium (P ⩽ 0.05), CL (P ⩽ 0.05), and conceptus (P ⩽ 0.08) compared to CON. On d 7 of the experiment, CSSO-supplemented cows had greater plasma progesterone concentrations (P < 0.01) and CL volume (P = 0.02) compared to CON, whereas no treatment effects were detected (P ⩾ 0.15) for these parameters on d 18 (treatment × day interaction; P < 0.01). Cows receiving CSSO tended (P = 0.09) to have greater concentrations of interferon-tau in the uterine flushing media compared with CON. However, no treatment effects were detected for mRNA expression genes associated with pregnancy establishment in endometrial, CL, and conceptus samples (P ⩾ 0.12). In summary, supplementing beef cows with 100 g of CSSO beginning after AI favored incorporation of ω-6 FA into their circulation, reproductive tissues, and conceptus, without impacting expression of genes associated with pregnancy establishment on d 19 of gestation. [ABSTRACT FROM AUTHOR]

Objectives were to determine the effect of source of supplemental Se and method of presynchronization on pregnancy rates and lactation performance of dairy cows. Holstein cows, 577, were enrolled in a 2x2 factorial design. Treatments were sodium selenite (SS) or Se yeast (SY, Sel-Plex™) supplemented at 0.3 ppm from 25 d prior to calving to 80 d in milk, and two methods of presynchronization, Presynch (2 PGF2a given 14 d apart) or CIDR inserted for 7 d with an injection of PGF2a at removal. Cows were AI following the Ovsynch protocol starting at 12 or 3 d after the presynchronization for Presynch and CIDR, respectively. Body condition was scored at study enrollment. Lactation performance was followed for the first 80 d postpartum. Cows were diagnosed for pregnancy at 28, 42 and 56 d after AI. Cows receiving SY produced (kg/d) more (P<0.05) 3.5% FCM (40.4 vs 38.5) and milk fat (1.42 vs 1.35) than SS, but yields of milk (41.1 vs 40.1) and true protein (1.14 vs 1.12), and SCC (120 vs 132 x 1000/mL) were all similar (P>0.10) between treatments. Body condition score was similar (P=0.45) for SY and SS throughout the study and averaged 3.08 and 3.07, respectively. Source of Se did not (P=0.23) influence cyclicity, but fewer (P=0.02) CIDR than Presynch cows were cyclic at the beginning of the Ovsynch (78.0 vs 86.1). Ovulatory responses were not influenced by source of Se. However, Presynch increased (P<0.01) ovulation to the first GnRH (73.5 vs 58.7), and size of ovulatory follicle at PGF (16.0 vs 15.2mm) and final GnRH (19.0 vs 18.2mm) of the Ovsynch, but did not influence ovulation at the final GnRH of the Ovsynch. Pregnancy on d 28 after first AI was not influenced (P>0.15) by source of Se (SY=31.2 vs SS=34.4%) or method of presynchronization (CIDR=33.0 vs Presynch=33.3%). Similarly, pregnancy loss from 28 to 56 d of gestation was not influenced (P>0.15) by Se (SY=23.5 vs SS=20.5%) or method of presynchronization (CIDR=22.5 vs Presynch=21.3%). SY improved lactation performance, but neither source of Se nor method of presynchronization altered pregnancy rates and embryonic survival in dairy cows. [ABSTRACT FROM AUTHOR]

Data from two studies conducted in different dairy farms in the Central Valley of California were compiled in order to investigate the relationships between high plasma NEFA concentrations and the incidence of sublcinical ketosis. Cows that had at least one plasma sample with concentration of B-hydroxybutyrate (BHBA) above 1.4mMol/L during the first 4 wk of lactation were considered positive. Data from 85 primiparous cows were obtained from study 1, while study 2 provided information from 175 primiparous (P) and 290 multiparous (M) cows. Concentrations of plasma NEFA were categorized for P (<0.50, 0.50 to 0.65, and >0.65 mMol of NEFA/L) and M cows (<0.46, 0.46 to 0.90 and >0.90 mMol of NEFA/L) according to concentrations at the first week postpartum. The mean (0.834 and 0.819 mMol /L) and median (0.749 and 0.754 mMol/L) concentrations of NEFA in plasma at one week postpartum were similar for P cows across study 1 and 2, respectively. Mean and median for M cows in study 2 were 0.865 and 0.787 mMol/L of NEFA, respectively. A logistic regression model that included the effects of NEFA category and study was utilized, while the two parity groups were analyzed separately. Concentration of NEFA in the first week of lactation had a major impact (P < 0.01) on the incidence of subclinical ketosis. Primiparous cows that had concentrations of NEFA in plasma greater than 0.65 mMol/L (n=154) at week 1 postpartum were 7.6 (OR) times more likely to experience high plasma concentrations of BHBA during the first 28 d in milk than herdmates in the < 0.50 mMol category group (n=47). Similar result was observed for M (OR=5.0; P <0.01) cows. Incidence of subclinical ketosis in the lower category group was 25.5 and 40.7%, for P and M, respectively. Management and nutritional practices that can alleviate the peak of NEFA could be a useful management tool to decrease the incidence of subclinical ketosis in early lactation. [ABSTRACT FROM AUTHOR]

The objectives of this study were to evaluate the effect of administering 500 mg of recombinant bovine somatotropin (bST) every 10 d on ovulatory responses, estrous behavior, and fertility of lactating Holstein cows. Lactating dairy cows were assigned to 1 of 2 treatments: a control with no administration of bST (73 primiparous and 120 multiparous cows) or 6 consecutive administrations of 500 mg of bST (83 primiparous and 123 multiparous cows) given subcutaneously at 10-d intervals starting 61 ± 3 d postpartum (study d 0), concurrent with the initiation of the timed artificial insemination (AI). Blood samples were collected thrice weekly from 61 ± 3 to 124 ± 3 d in milk (DIM), and plasma samples were analyzed for concentrations of estradiol, glucose, insulin, insulin-like growth factor 1, and progesterone. The estrous cycle of cows was presynchronized with 2 injections of PGF2α at 37 ± 3 and 51 ± 3 DIM, and the Ovsynch timed AI protocol was initiated at 61 ± 3 DIM. Ovaries were scanned to determine ovulatory responses during the Ovsynch protocol. Pregnancy was diagnosed at 33 and 66 d after AI. Body condition was scored on study d 0, 10, 42, and 76. Sixty-four cows were fitted with a pressure mounting sensor with radiotelemetric transmitters to monitor estrous behavior. Treatment of lactating dairy cows with 500 mg of bST at 10-d intervals increased yields of milk and milk components in the first 2 mo after treatment. Body condition of bST-treated cows remained unaltered, whereas control cows gained BCS. Treatment with bST increased concentrations of insulin- like growth factor 1 chronically, but concentrations of insulin and glucose increased only transiently in the first 7 d after the first injection of bST. Concentrations of progesterone during and after the Ovsynch protocol remained unaltered after treatment with bST; likewise, ovulatory responses during the Ovsynch protocol were mostly unaltered by treatment. Concentration of estradiol tended to be greater for bST cows than for control cows immediately before induction of ovulation in the Ovsynch protocol. Similarly, the mean and the peak concentrations of estradiol were greater for bST cows than for control cows when monitored during spontaneous estrus. Nevertheless, duration of estrus and the median number of standing events were less for bST cows than for control cows. Pregnancies per AI after the first and second postpartum inseminations were not affected by bST treatment. Treatment of lactating dairy cows with 500 mg of bST every 10 d improved lactation performance, but it did not affect pregnancies per AI and it reduced expression of estrus. [ABSTRACT FROM AUTHOR]

The objectives of this study were to determine the effects of incorporating a progesterone intravaginal insert (CIDR) between the day of GnRH and PGF2α treatments of a timed AI protocol using estradiol cypionate (ECP) to synchronize ovulation on display of estrus, ovulation rate, pregnancy rate, and late embryonic loss in lactating cows. Holstein cows, 227 from Site I and 458 from Site 2, were presynchronized with two injections of PGF2α on study d 0 and 14, and subjected to a timed AI protocol (100 µg of GnRH on study d 28, 25 mg of PGF2α on study d 35, 1 mg of ECP on study d 36, and timed AI on study d 38) with or without a CIDR insert. Blood was collected on study d 14 and 28 for progesterone measurements to determine cyclicity. Ovaries were scanned on d 35, 37, and 42, and pregnancy diagnosed on d 65 and 79, which corresponded to 27 and 41 d after AI. Cows receiving a CIDR had similar rates of detected estrus (77.2 vs. 73.8%), ovulation (85.6 vs. 86.6%), and pregnancy at 27 (35.8 vs. 38.8%) and 41 d (29.3 vs. 32.3%) after AI, and late embryonic loss between 27 and 41 d after AI (18.3 vs. 16.8%) compared with control cows. The CIDR eliminated cows in estrus before the last PGF2α injection and decreased (P < 0.001) the proportion of cows bearing a corpus luteum (CL) at the last PGF2α injection because of less ovulation in response to the GnRH and greater spontaneous CL regression. Cyclic cows had greater (P = 0.03) pregnancy rates than anovulatory cows at 41 d after AI (33.8 vs. 20.4%) because of decreased (P = 0.06) late embryonic loss (16.0 vs. 30.3%). The ovulatory follicle was larger (P < 0.001) in cows in estrus, and a greater proportion of cows with follicles ≥ 15 mm displayed estrus (P < 0.001) and ovulated (P = 0.05) compared with cows with follicles <15 mm. Pregnancy rates were greater (P < 0.001) for cows displaying estrus, which were related to the greater (P < 0.001) ovulation rate and decreased (P = 0.08) late embryonic loss for cows in estrus at AI. Cows that were cyclic and responded to the presynchronization protocol (high progesterone at GnRH and CL at PGF2α) had the highest pregnancy rates. Incorporation of a CIDR insert into a presynchronized timed AI protocol using ECP to induce estrus and ovulation did not improve pregnancy rates in lactating dairy cows. Improvements in pregnancy rates in cows treated with ECP to induce ovulation in a timed AI protocol are expected when more cows display estrus, thereby increasing ovulation rate. [ABSTRACT FROM AUTHOR]

Although in recent years the use of purine analogues has increased the percentage of long‐term complete response the effect on overall survival of HCL patients is not yet clear. This study aimed to evaluate the long‐term outcome (mean follow up of 92 months) of sixty‐four patients receiving IFN as first‐line therapy. IFN was well tolerated and effective. The overall response rate was 91% (PR 65%, CR 13%, GPR 13%). Forty‐one patients (63%) received IFN 3 MU/wk as maintenance therapy. The 10‐yr projected survival rate of responding patients (CR and GPR 100%; PR 95%) and non responders (SD, PD 80%) clearly shows that type of response does not affect survival. Patients receiving IFN maintenance had a statistically higher PFS than those who did not (p<0.01). This study shows that IFN is still one of the standard therapies for this disease, that achieving CR has no primary relevance for the control of the disease, and that good utilization of therapeutic resources may assure HCL patients a survival rate comparable to that of a normal, healthy population. [ABSTRACT FROM AUTHOR]

Abstract: We report an experimental study of metrological properties of high-temperature superconductor arrays, made of shunted bicrystal YBCO Josephson junctions. The work is mainly based on a direct comparison against a low temperature array. Owing to the high sensitivity of the measurements, we observed at nanovolt level the changes in the HTS array voltage on a step. A precise estimate of the dependence of the HTS array step width on operating conditions was obtained. Differences were observed with respect to the results of low sensitivity techniques, confirming that our method is necessary in the study of HTS arrays for metrology. The high sensitivity analysis was also applied in the derivation of the temperature dependence of the critical current, providing insights on the behavior of the HTS array. [Copyright &y& Elsevier]

Presents a letter to the editor commenting on an article about second malignancy after treatment of adult acute myeloid leukemia.

This experiment compared ovarian, uterine and conceptus factors associated with pregnancy establishment in Bos indicus beef cows according to estrus expression during a timed-AI protocol. One hundred lactating multiparous Nelore cows received a 2 mg injection of estradiol benzoate and an intravaginal progesterone (P4) releasing device on d -11, a 12.5 mg injection of PGF2α on d -4, P4 device removal in addition to 0.6 mg injection of estradiol cypionate and 300 IU injection of eCG on d -2, and timed-AI on d 0. All cows were inseminated by the same technician with semen from a single bull. An estrus detection patch was attached to the tailhed of each cow on d -2, and estrus expression was defined as removal of > 50% of the rub-off coating from the patch on d 0. Overall, 39 cows expressed estrus (EST), 55 did not express estrus (NOEST), and 6 cows lost their patch and were removed from the experiment. Transrectal ultrasonography was performed to verify ovulation and corpus luteum (CL) volume immediately before AI (d 0), on d 7 and 15. After ultrasonography on d 15, 60 cows (29 EST and 31 NOEST) diagnosed without the presence of a CL on d 0, but with a CL greater than 0.38 cm3 in volume on d 7 and 15, were assigned to conceptus collection via transcervical flushing with PBS followed by endometrial biopsy in the uterine horn ipsilateral to the CL. Blood samples were collected for whole blood RNA extraction (d 20) and pregnancy status was verified by transrectal ultrasonography (d 30) in cows not assigned to conceptus collection. Diameter of dominant follicle on d 0 was greater in EST vs. NOEST (13.8 vs. 12.4 mm; SEM = 0.4). Conceptus length and mRNA expression of prostaglandin E synthase and interferon-tau were greater (P ≤ 0.04) in EST vs. NOEST (2.74 vs. 0.98 cm, SEM = 0.59; 22.24 vs. 3.98 fold effect, SEM = 5.62; 8.17 vs. 2.78 fold effect, SEM = 1.72; respectively). Moreover, EST cows diagnosed as pregnant on d 30 had greater (P < 0.01) blood mRNA expression of myxovirus resistance 2 on d 20 compared with NOEST cohorts (57.5 vs. 27.1 fold effect; SEM = 5.05). Hence, estrus expression near the time of AI enhanced pregnancy establishment factors in B. indicus cows, including conceptus growth and mRNA expression of interferon-tau, as well as blood mRNA expression of a interferon-stimulated gene. [ABSTRACT FROM AUTHOR]

Two experiments investigated the effects of supplementing Ca salts of soybean oil (CSSO) during early gestation on reproductive function and pregnancy rates to timed-AI in B. taurus beef cows. In Exp. 1, 771 lactating multiparous Angus cows were divided into 22 groups of approximately 35 cows/group, and timed-AI on d 0. After AI, groups were randomly assigned to receive (as-fed basis) 200 g/cow daily of a corn-based supplement and: 1) 100 g/cow daily of CSSO (n = 11; Essentiom; Church and Dwight Co., Inc., Princeton, NJ) or 2) 100 g/cow daily of prilled SFA (CON, n = 11; EnergyBooster; Milk Specialties, Eden Prairie, MN). Groups were maintained in individual pastures with free-choice access to forage, and offered treatments from d 0 to 21. Pregnancy status was determined on d 30 via transrectal ultrasonography. Cows receiving CSSO had greater (P = 0.01) pregnancy rates to timed-AI compared with CON cows (60.2 vs. 51.7%; SEM = 4.2). In Exp. 2, 90 lactating multiparous Angus cows housed in 18 drylot pens (5 cows/pen) were assigned to the same timed-AI program and treatments from Exp. 1 (9 pens/ treatment), receiving 20 kg/d (DM basis) of grass-alfalfa hay. Transrectal ultrasonography was performed to verify ovulation and corpus luteum (CL) volume immediately prior to AI, d 7, and 15. Within each treatment, 22 cows diagnosed without the presence of a CL on d 0, but with a CL greater than 0.38 cm3 on d 7 and 15, were assigned to conceptus collection via transcervical flushing with saline followed by endometrial biopsy on d 15. Both procedures were performed in the uterine horn ipsilateral to the CL. Blood samples were collected for whole blood RNA extraction (d 20) and pregnancy diagnosis (d 30; BioPRYN; Gold Standard Labs, Bowling Green, KY). Conceptus from cows receiving CSSO had greater (P ≤ 0.05) mRNA expression of interferon-tau vs. conceptus from CON cows (21.3 vs. 12.1 fold effect; SEM = 3.4). Within cows diagnosed as pregnant on d 30, blood mRNA expression of interferon-stimulated gene 15 and 20,50-oligoadenylate synthetase on d 20 were greater in CSSO vs. CON cows (43.1 vs. 29.8 fold effect, SEM = 4.6; 26.8 vs. 18.3 fold effect, SEM = 2.7; respectively). Hence, post-AI CSSO supplementation to beef cows increased pregnancy rates to timed-AI compared with non-supplemented cows, which can be attributed to increased mRNA expression of interferon-tau by the conceptus when CSSO is supplemented during early gestation. [ABSTRACT FROM AUTHOR]

In this experiment (d 0 to 41), 290 lactating, primiparous and multiparous non-pregnant Brangus cows received a 2 mg injection of estradiol benzoate and an intravaginal progesterone (P4) releasing device (CIDR) on d 0, a 12.5 mg injection of PGF2a on d 7, CIDR removal in addition to 0.6 mg injection of estradiol cypionate and 300 IU injection of eCG on d 9, and fixed-time AI on d 11. All cows were inseminated by the same technician with semen from a single bull. On d 7, cows were fitted with a pedometer behind their left shoulder. On d 9, an estrus detection patch was attached to the tailhed of each cow. On d 11, estrus was defined as removal of >50% of the rub-off coating from the patch. Cow activity (total steps) was calculated by subtracting d 7 to 9 results (basal activity) from d 9 to 11 results (expected estrus period). Cows were classified by estrus intensity according to physical activity as: NOESTRUS = cows that did not express estrus; or cows that expressed estrus with physical activity below (LOWESTRUS) or above (HIESTRUS) the population median. Ovarian transrectal ultrasonography was performed on d 11 and 18. Blood was collected concurrently with ultrasonography exams for plasma P4 analysis. Pregnancy status was verified by transrectal ultrasonography on d 41. Only data from cows that ovulated to the synchronization protocol and that were successfully classified according to estrus characteristics were utilized (NOESTRUS, n = 57; LOWESTRUS, n = 87; HIESTRUS, n = 90). Diameter of dominant follicle on d 11, CL volume on d 18, and plasma P4 concentrations on d 18 were greater (P ≤ 0.05) in HIESTRUS vs. LOWESTRUS and NOESTRUS, and also greater (P ≤ 0.05) for LOWESTRUS vs. NOESTRUS (14.1, 13.4, and 12.5 mm, SEM = 0.3; 5.5, 4.9, and 3.6 cm3, SEM = 0.5; and 4.7, 4.0, and 3.0 ng/mL; SEM = 0.2). Plasma P4 on d 11 were greater (P < 0.01) in NOESTRUS vs. HIESTRUS and LOWESTRUS, and similar (P = 0.36) between HIESTRUS and LOWESTRUS (0.47, 0.30, and 0.25 ng/mL; SEM = 0.07). Pregnancy rates were less (P ≤ 0.04) in NOESTRUS vs. HIESTRUS and LOWESTRUS, and similar (P = 0.38) between HIESTRUS and LOWESTRUS (42.0, 67.3 and 60.5, SEM = 7.1). Hence, estrus expression and intensity, estimated by physical activity after CIDR removal, impacted fertility parameters and pregnancy success in Brangus cows. [ABSTRACT FROM AUTHOR]