Controlled Internal Drug Release Research Articles

Effect of the feeding condition and number of dominant follicles on oestrus synchronization in Swamp buffalo

The research aimed to assess how feeding conditions and the number of the dominant follicles (DF) influence oestrus synchronization in swamp buffaloes. A total of 170 swamp female buffaloes raised in semi-grazing and housekeeping were included in the study. The synchronization used CIDR method and the follicles on the day of CIDR (Controlled Internal Drug Releasing) insert and removal were tracked by sonography. The results indicated that the age of first mating, age at first calving, and caving interval showed no significant differences in the two feeding conditions. The number of follicles at CIDR insertion and removal decreased in semi-grazing, but increased in housekeeping buffaloes. The percentage of buffalo without DF, one DF, and two DFs at CIDR withdrawal did not differ statistically. The percentage of estrus was 100% in both groups. Pregnancy rates were 53.18% in semi- grazing and 52.63% in housekeeping. The onset of oestrus was similar, but the duration of oestrus was longer in the buffaloes without DF than those with one or two DFs. The percentage of pregnant buffaloes in the group without DF was significantly lower than that in the other two groups. In summary, the efficiency of oestrus synchronization did not differ between semi-grazing and housekeeping methods. Buffaloes without DF displayed longer oestrus periods and lower pregnancy rates compared to those with one or two DFs in the ovarian system.

Influence of repeated estrus synchronization treatment on hormone secretion, growth, and development of dairy goats.

In large-scale intensive farms, dairy goats often undergo frequent estrus synchronization (ES) treatment, which may result in a decline in reproductive performance; however, the underlying mechanism remains unclear. The present study aimed to investigate the effect of pregnant mare serum gonadotropin (PMSG) and progesterone (P4)-mediated ES treatment on fertility in dairy goats, while also identifying key metabolic and endocrine mechanisms that influence reproductive performance in does subjected to repeated ES treatment. Forty-eight Saanen does were randomly assigned to two groups (24 goats each) that received ES treatments either thrice fortnightly (3-PMSG) or once (1-PMSG) simultaneously with the third ES treatment of the 3-PMSG group during the breeding season. ES treatment was performed via the intravaginal insertion of a controlled internal drug release (CIDR) device impregnated with 300 mg P4, followed by 300 IU PMSG injections 48 h before CIDR withdrawal. Blood was collected to detect the level of hormones and blood biochemical indices. Additionally, estrus rate, fecundity rate, body weight, size, and lactation performance were measured. The results showed that repeated ES treatment markedly decreased the estrus rate and fecundity rate of goats. Among the does in all groups, there was no substantial difference in follicle stimulating hormone, luteinising hormone, gonadotropin-releasing hormone, melatonin, growth hormone, PMSG, total cholesterol, total protein, and glucose levels, as well as the body weight, body size, and lactation performance. Repeated ES treatment elevated estrogen (E2) levels 36, 48, and 72 h post-CIDR removal; increased P4 upon CIDR insertion; and raised PMSG antibody levels 24, 48, and 72 h post-CIDR removal. The results suggest that elevated anti-PMSG levels are the primary reason for the decline in ES efficiency, and that high E2 and P4 levels at some time points also impair reproductive performance. These findings provide novel insights into the metabolic effects of repeated PMSG stimulation in goats, guiding future reproductive hormone use in breeding practices.

Magnitude and persistence of higher estrus-associated temperatures in beef heifers and suckled cows.

Higher estrus-associated temperatures (HEAT) are a hallmark feature in sexually active females. The overarching aim of this study was to characterize the variability, magnitude, and persistence of HEAT in heifers and suckled beef cows as well as identify associated factors when occurring during thermoneutral conditions at the onset of the spring breeding season. In both heifers and cows, estrus was induced using a 7-d controlled internal drug release (CIDR)-PGF2α protocol. Vaginal temperature after prostaglandin F2α administration was recorded every 5min using a Thermochron iButton affixed to a blank CIDR (containing no progesterone). Estrus was defined as when a heifer first stood to be mounted or when a cow had an Estrotect patch score of 3 or 4. Level of HEAT varied among individual animals. When comparing common HEAT variables using a mixed model with date nested within a year, maximum HEAT (39.9 ± 0.1 and 40.0 ± 0.1 °C) and duration (15.5 ± 0.8 and 15.4 ± 0.7) were similar in heifers and cows, respectively. However, the magnitude and persistence of HEAT differed. Total area under the HEAT curve was 117.1 ± 13.5 and 158.7 ± 12.3 for heifers vs cows, respectively (P = 0.0571). Further, 42.9% of heifers and 49% of cows had maximum HEAT ≥ 40 °C which persisted up to 6.5 and 10h, respectively. When ambient conditions were predominantly thermoneutral, temperature humidity index had minimal impact on HEAT (mixed model, repeated measures over time). Toward identifying associated factors with different aspects of HEAT using best fit hierarchical linear regression models, baseline vaginal temperature and baseline duration were the most highly associated independent variables. Follicle size, estradiol and progesterone levels, and other available animal-related variables (e.g., age, weight, hair coat score) explained only a small amount of variation in HEAT. In summary, level of HEAT varies in estrus females even under thermoneutral conditions. Because HEAT can persist for an extended time, direct effects on fertility important components are unavoidable. Whether HEAT is a good or bad component of the periovulatory microenvironment is the basis of ongoing and future studies.

Ovarian dynamics in progesterone tablet-induced superovulation in goats assessed by magnetic resonance imaging.

Controlled internal drug-releasing (CIDR) devices are commonly used for superovulation in goats. However, such devices are unavailable in some countries, including Japan. In this technical note, we aimed to explore the efficacy of an alternative superovulation protocol using progesterone tablets in goats. We employed intravaginal progesterone tablets (LUTINAS® Vaginal Tablet 100 mg) following a standard superovulation protocol. Additionally, we assessed the ovarian dynamics using 3T-magnetic resonance imaging (MRI) 1day preceding the progesterone treatment (Day "-1") and 3days before the end of treatment (Days 11-13). The ovarian monitoring was successfully performed in the short tau inversion recovery T2-weighted images of MRI, and ovulation was confirmed by the disappearance of follicles on Day 13 post-administration of the tablets. Immediately after ovulation, oviduct flushing yielded a substantial number of oocytes (13.5 ± 1.8 oocytes per animal). These findings provide evidence that the administration of progesterone tablets can serve as a viable alternative for inducing. Additionally, our findings suggest that 3T-MRI is a promising alternative to conventional ultrasonography for monitoring ovarian dynamics following superovulation in experimental goats.

Relationship between higher estrus-associated temperatures and the bovine preovulatory follicular fluid metabolome

IntroductionA higher estrus-associated temperature (HEAT) is a hallmark feature in sexually active females; however, its functional importance is unclear. Our objective was to examine the relationship between HEAT and the preovulatory follicular fluid metabolome. It was hypothesized that HEAT is functionally important as it affects fertility-related components in the preovulatory follicle.MethodsEstrus was synchronized in non-lactating Jersey cows. A Thermochron iButton temperature data logger was affixed to blank controlled internal drug release (CIDR) devices and intravaginally inserted after CIDR device removal. The follicular fluid was aspirated 14.9 h + 3.3 h after an animal first stood to be mounted. Regression models were performed using metabolite abundance and HEAT variables. Best-fit models were determined using backward manual selection (p < 0.05).ResultsA total of 86 metabolites were identified in cow follicular fluid samples. The vaginal temperature at first mount and when it was expressed as a change from baseline was positively related to the abundance of four metabolites (i.e., taurine, sn-glycerol 3-phosphate, glycine, and cysteine) and negatively related to one metabolite (i.e., serine). The vaginal temperature at the first standing mount was related to the differential abundance of two metabolites (i.e., jasmonate and N-carbamoyl-L-aspartate). Three metabolites were related to the maximum vaginal temperature (i.e., N-carbamoyl-L-aspartate, uracil, and glycodeoxycholate). When expressed as a change from baseline, the maximum vaginal temperature was related to the differential abundances of uracil, uric acid, and 6-phospho-D-gluconate. The time taken to reach maximum vaginal temperature was related to N-carbamoyl-L-aspartate, glycodeoxycholate, jasmonate, and tricarballylic acid. Pertaining to the combination of HEAT and its duration, the area under the curve associated with the time between the first increase in vaginal temperature and the maximum vaginal temperature was related to 6-phospho-D-gluconate, sulfolactate, guanidoacetic acid, and aspartate. The area under the curve associated with the time between the initial vaginal temperature increase and up to 10 h after a cow first stood to be mounted or when a cow’s temperature returned to baseline was related to the differential abundances of uracil, sn-glycerol 3-phosphate, methionine sulfoxide, and taurodeoxycholate.DiscussionOur findings support the notion that HEAT is related to changes in the preovulatory follicular fluid metabolites involved in energy metabolism, thermoregulation, and oxidative stress management.

291 Impact of Early Resynchronization in Combination with Color Doppler Ultrasonography on Cumulative Pregnancy Rates in Postpartum Beef Cows

Abstract The objective of this study is to evaluate a GnRH and progesterone-based early resynchronization strategy combined with color Doppler ultrasonography for early pregnancy diagnosis. Postpartum Bos taurus beef cows (n = 375) from four locations were enrolled in a completely randomized design, where cows were randomly assigned to 1 of the 2 treatments: 1) Natural Service (NS), cows were exposed to a 7-d CO-Synch + CIDR protocol followed by fixed-time artificial insemination (day 0). On day 15, cows were exposed to natural service for the remainder of the study; or 2) Early Resynchronization (ER), cows were exposed to a 7-d CO-Synch + CIDR protocol followed by fixed-time artificial insemination (day 0). On day 15, a controlled internal drug release (CIDR) device was inserted. On day 20, CIDR was removed, and pregnancy was estimated based on luteal blood perfusion using color Doppler ultrasonography. Non-pregnant cows received a 25-mg injection of prostaglandin F2α at CIDR removal and were fixed-timed-AI concurrently with a 100-μg injection of GnRH 60 to 66 h later. Pregnancy diagnosis and fetal aging were performed on day 53 using conventional ultrasonography. Pregnancy rate to the first AI was greater (P = 0.03) for NS compared with ER (70.25% vs 59.29%, respectively). Pregnancy rates for the second service were also greater (P = 0.01) for NS compared with ER (65.67 vs 42.93%, respectively). Cumulative pregnancy rates to AI did not differ between treatments (P = 0.38); however, cumulative pregnancy rates (first and second service) were greater (P < 0.01) for NS compared with ER (90 vs 77.73%, respectively). In conclusion, the proposed early resynchronization strategy using color Doppler ultrasonography resulted in fewer pregnancies compared with natural service as the second service strategy. Moreover, the proposed ER decreased pregnancy rates to the first insemination, indicating a detrimental effect of ER on pregnancy establishment.

Timing of ovulation in the fat-tailed Qezel ewes after synchronization with vaginal devices containing endogenous or exogenous synthetic progestogens during out of the breeding season.

Wide range of ovulation distribution is the main restricting factor in establishing the pregnancy following oestrus synchronization (ES) and fixed time insemination (FTI) in sheep. Determining the ovulation time (OVT) following ES with two different vaginal devices, its relation to progesterone and conception upon FTI with frozen/thawed semen. Oestrus was synchronized using either controlled internal drug release (CIDR) (ewe, n=6; ewe lamb, n=5) or vaginal sponge (ewe, n=6; ewe lamb, n=5) insertion for 12 days, plus Equine chorionic gonadotropin (eCG) at devices removal (Day 0). Sizes of the ovarian follicles were measured using transvaginal probe at -12, 0 and 30-33, 53h and continued every 3-4h until 75h after eCG treatment. Serum progesterone amounts were measured at -12, 0, +2 and +11. Laparoscopic FTI was done at 60.5±0.5h. The CIDR-treated group initiated and completed ovulations earlier compared to sponge-treated females (median: 64 vs. 71h; p<0.05). Ewe lambs were ovulated earlier compared to ewes in the sponge-treated group (66.71 vs. 71.5; p=0.017). Mean sizes of ovulatory follicles and corpora lutea were not affected by device types. Higher amounts of progesterone were observed in CIDR group compared to sponge-treated group at device removal (2.68±0.12 vs. 0.30±0.01ng/mL; p<0.001). The conception was confirmed in 2/10, and 5/11 females of sponge and CIDR-treated females, respectively. Types of progestogens influence the OVT, and consequently the result of FTI with frozen/thawed semen. The optimum timespan for FTI should be chosen according to the device types during non-breeding season.

Embryo yield and quality in superovulated Simmental donor cows following oral supplementation with different sources of omega-3 and omega-6 fatty acids

Owing to contradictory results with respect to the yield and quality of embryos after supplementation with omega-3 fatty acids, this study sought to determine the effect of an oral supplement containing sources of omega-3 and omega-6 fatty acids on the ovarian response and embryo quality after superovulation. Cows were allocated to receive one of three oral supplement regimens. In the control (CO) group (n = 9), cows were fed a control supplement without fatty acids. The cows in the soybean oil (SO) (n = 8) and linseed oil (LO) (n = 8) groups received supplements containing SO or LO, respectively. Supplements were administered for 28 days, commencing 7 days before the onset of estrus synchronization until the day of embryo collection. The estrous cycle of all cows was synchronized by inserting a controlled internal drug release (CIDR) device (progesterone 1.38 g), followed by the administration of estradiol benzoate 2.5 mg. The CIDR device was withdrawn 7 days after insertion, followed by intramuscular administration of dinoprost 25 mg. Superovulation was induced via the administration of 152 mg of follicle-stimulating hormone (Folltropin-V) in tapered doses, starting 72 h before CIDR withdrawal. The embryos were collected 6 days after artificial insemination. The estrous response, onset of estrus after CIDR withdrawal, and number of ovulations were similar among the experimental groups (p > 0.05). The mean number of transferable embryos (grades 1 and 2) was higher in the LO group compared to the CO group (9.0 vs 3.2; p < 0.05). Although the number of transferable embryos (grades 1 and 2) was greater in the LO group than that in the SO group, the difference was not statistically significant (9.0 and 4.4; p > 0.05). In conclusion, oral supplementation with LO for 28 days increased the yield of transferable embryos, which could potentially improve the profitability of embryo transfer programs in cattle.

A single dose of FSH or hCG during a split-time AI program did not enhance follicular growth or pregnancy per artificial insemination in beef heifers

ABSTRACT The objective of this study was to evaluate the effect of a low dose of hCG or FSH on follicle growth and pregnancy per artificial insemination (AI) in crossbreed beef heifers subjected to a split-time AI program. All heifers (n = 386) were subjected to a 7-d Co-synch protocol and an intravaginal controlled internal drug release (CIDR) device (GnRH and CIDR insertion; 7 days later PGF2α, CIDR removal, and application of a tail head estrus detection patch; 36 hours later AI of heifers detected in estrus, 24 hours later timed AI of remaining heifers). At CIDR removal, heifers were randomly assigned to receive either 150 IU of hCG, 20 mg of FSH, or remained as untreated controls. The diameter of the preovulatory follicle and the pregnancy per AI did not differ among treatments. A smaller (P = 0.035) proportion of heifers in the hCG group were detected in estrus compared with control. Additionally, the incidence of premature ovulation was greater (P < 0.01) among heifers treated with hCG compared with control. In conclusion, using a low dosage of hCG or FSH at the time of device removal did not affect pre-ovulatory follicle growth or the proportion of pregnant heifers.

55 Investigating the Potential Benefits of an Immunostimulant (Mycobacterium Cell Wall Fraction) Treatment on Increased Pregnancy Success of Embryo Transfer Recipients

Abstract Modulating the vaginal and uterine microbiome through the use of immunostimulants has the potential to improve fertility in cattle. The object of this study was to evaluate the potential benefits of an immunostimulant, mycobacterium cell wall fraction (MCWF), to increase pregnancy success of embryo transfer (ET) recipients. The three main objectives of this study were: determining if injecting ET recipient cows with MCWF increased proportion of cows with a corpus luteum (CL) on ET day, identifying differences in CL volume and progesterone concentration at the time of ET, and determining if ET recipients that received MCWF have greater pregnancy rate. A total of 926 beef cows at eight different locations were enrolled in this study. Primiparous and multiparous cattle were enrolled in a 7-day CO-Synch + CIDR estrous synchronization protocol. During this protocol, cows received an injection of GnRH (100-μg) at CIDR (controlled internal drug release) insertion [d -9], a prostaglandin F2α injection (25 mg), and CIDR removal [d-2] followed by another injection of GnRH (100 μg; d 0) within 60-66 hours after CIDR removal. At each location at (d 0), cows were sorted based on BCS and days post-partum and randomly assigned to one of two treatments: 1) MCWF- a single intramuscular injection (5 mL) of MCWF at (d 0; Amplimune, NovaVive Inc.; n = 452) or 2) Control- a single intramuscular injection (5 mL) of saline (n = 474). Seven days after (d 7), cows were examined by ultrasonography to determine if a CL was present. Recipient cows that had a CL received ET with a frozen or fresh in vivo or in vitro produced embryo in the ipsilateral uterine horn to the CL, with embryo type and grade balanced between treatments. Blood samples were collected in one location (n = 98) for analysis of plasma concentration of progesterone on (d 7) ET day. Pregnancy diagnosis was then performed by ultrasonography between 30 and 90 days of gestation. Data were analyzed using the GLIMMIX and MIXED procedures of SAS. Cow BCS and days postpartum were similar (P &amp;gt; 0.10) between treatments (5.5 ± 0.6 and 103 ± 14 days, respectively). Recipient cow utilization rate was similar between treatments (P = 0.49; 81.2 ± 0.42%). At the time of ET MCWF had larger CL than Control cows (5,768.6 ± 133.7 and 5,408.0 ± 128.5 mm3, respectively, P = 0.03). and increased progesterone concentration (2.68 ± 0.17 and 2.18 ± 0.14 ng/mL, respectively, P = 0.01). However, pregnancy rate to ET was similar (P = 0.922) between treatments (60.9 and 61.3 ± 0.05% for Control and MCWF, respectively). In conclusion, treatment of ET recipient cows with MCWF increased CL volume and concentration of progesterone at the time of ET but failed to generate greater pregnancy rates.

94 Changes in Vaginal Microbiome of Beef Cows Enrolled in an Estrous Synchronization Protocol

Abstract Vaginal pH and microbiome have been reported to influence fertility in women. In cattle, estrous synchronization protocols are a great tool to overcome infertility; however, the effects of the hormones administered in the protocol on vaginal microbiome and pH are unknown. A total of 24 cows were enrolled in the 7-d Co-Synch + controlled internal drug release (CIDR) protocol and had individual vaginal flushes collected during the handling events of the protocol on days 0, 7 and on day 10 at timed-artificial insemination (TAI). Flushes were used for pH analysis and DNA extraction. Extracted DNA was submitted to analysis by whole genome shotgun sequencing. Pregnancy status was assessed by ultrasonography 35 days after TAI. Firmicutes was the most abundant phylum, followed by Proteobacteria, and Actinobacteria for all collection days. Bacteria from the Clostridia genus were the most abundant in all samples. Greater alpha Shannon diversity (within sample diversity) was observed for pregnant animals on day -10 compared with non-pregnant animals at the phylum, class, and order (P &amp;lt; 0.01), as well as family, and genus level (P &amp;lt; 0.001). Overall, Shannon diversity was decreased on day 7 compared with day 0 (P &amp;lt; 0.05 at class and order level; P&amp;lt; 0.01 at genus and family level) and was greater at TAI compared with day 7 (P &amp;lt; 0.01 at the phylum, class, and order level; P &amp;lt; 0.001 at family and genus level). No differences were observed for Shannon diversity between samples from D0 and TAI (P &amp;gt; 0.05). No correlations between Shannon diversity were observed in relation to vaginal pH (P &amp;gt; 0.1). Bray-Curtis analysis (between sample diversity) revealed clustering by day (P &amp;lt; 0.05 at the order, family, and genus level) and a tendency (0.1 &amp;lt; P &amp;lt; 0.05) at the phylum and class level. In conclusion, greater fertility was observed for animals with greater within sample diversity prior to protocol initiation. Furthermore, vaginal bacterial diversity changes throughout the protocol, with decreased diversity observed on day 7 of the protocol, but restored diversity on day0 at TAI.

Addition of equine chorionic gonadotropin in controlled internal drug-release-based synchronization improves reproductive performance of Nili-Ravi buffalo in the sub-tropics

This study evaluated the effect of equine chorionic gonadotropin (eCG) and factors such as body condition score (BCS), cyclicity, and breeding season in a controlled internal drug release (CIDR)-based oestrus synchronization protocol on ovarian follicle dynamics, oestrus expression, ovulation rate, and pregnancy per artificial insemination (AI) (P/AI) in Nili-Ravi buffalo. Adult buffaloes (n = 88), 6.69 ± 1.17 years, parity 3.36 ± 0.97, and BCS 2.76 ± 0.45, were randomly administered eCG or saline, concurrent with prostaglandin F2α (PGF2α) treatment on Day 6 in a CIDR synchronization protocol during the breeding season and low breeding season. Follicular dynamics and oestrus expression were recorded from eCG administration until ovulation. Fixed-time artificial insemination (FTAI) was performed at 48- and 60-hour intervals after CIDR withdrawal. On Day 35 post-AI, pregnancy was diagnosed with ultrasonography. There was no significant difference in the size of the ovulatory follicle between eCG-treated buffaloes (ETB) and saline-treated buffaloes (STB). The growth rate of the dominant follicle, oestrus response and intensity, ovulation, and P/AI were higher (P &lt;0.05) in eCG-treated buffaloes. It was concluded that eCG improved the growth rate of the dominant follicle, oestrus expression, and P/AI in a CIDR-based FTAI programme in Nili-Ravi buffalo. The deleterious effects of poor BCS, acyclicity, and low breeding season could be reduced with a progesterone-based fixed time AI protocol with the addition of eCG.

Role of aquaporin 3 in reproductive performance of dairy goats after repeated estrus synchronization stimulation.

This study explored the specific molecular mechanisms through which repeated estrus synchronization (ES) treatments reduce the reproductive performance of dairy goats. Ninety-six goats (n=24/group) were randomly assigned to two groups receiving ES treatments thrice every fortnight (3- equine chorionic gonadotropin [eCG] and 3-follicle stimulating hormone [FSH] groups) and two groups receiving one ES treatment (1-eCG and 1-FSH groups). ES treatments of 1- and 3-eCG goats were performed via the intravaginal insertion of a controlled internal drug release (CIDR) device containing 300 mg progesterone (P4), followed by 300 IU eCG injections 48 h before CIDR withdrawal. The 1- and 3-FSH goats received CIDR for 10 d, followed by 50 IU FSH and 100 μg PGF2α within 12 h of CIDR withdrawal. Ovaries of three goats in estrus from both groups were harvested for analysis. Subsequently, all the goats in estrus were artificially inseminated twice. Consequently, 3-eCG and 3-FSH goats showed a considerably reduced estrus rate and litter size than 1-eCG and 1-FSH goats. AQP3 mRNA and protein expression were significantly higher in the 3-eCG and 3-FSH groups than in the 1-eCG and 1-FSH groups. AQP3 overexpression led to cell apoptosis and decreased steroid hormone secretion ability of ovarian granulosa cells. Moreover, it resulted in a decrease in maturation and cleavage rates after parthenogenetic activation and in vitro fertilization, respectively. AQP3 gene was involved in reducing the reproductive performance of repeated ES-treated dairy goats. These findings provide a theoretical foundation for the effective use of reproductive hormones in breeding techniques for livestock.

Effect of subclinical endometritis and flunixin meglumine administration on pregnancy in embryo recipient beef cows

Fertility of recipient beef cows with subclinical endometritis (SCE) that did or did not receive flunixin meglumine (FM) treatment were compared following transfer of d 7 embryo. The study population comprised of 600 Angus cross cows that expressed estrus following Select-Synch + CIDR (Controlled Internal Drug Release) estrus synchronization protocol. At the time of embryo transfer, approximately 3 wk after sampling for subclinical endometritis, cows were randomly allocated either to receive FM treatment (500 mg of Banamine®; n = 300) or not (Control; n = 300). The effect of subclinical endometritis (at ≥ 1% PMN on endometrial cytology by cytobrush method) and FM treatment on pregnancy/embryo transfer (P/ET, %) were evaluated by mixed model. Of the 600 cows, 323 (53.8%) became pregnant; 55.0% (165/300) cows that received FM treatment vs. 52.7% (158/300) control cows (P > 0.1), and 55.9% (266/476) normal vs. 46.0% (57/124) subclinical endometritis cows (P < 0.05). There was a trend for treatment by subclinical endometritis for P/ET (P = 0.09). Pregnancy was recorded in 55.3% (134/242) of normal and 53.4% (31/58) of subclinical endometritis cows that received FM treatment, and in 56.4% (132/234) of normal and 39.4% (26/66) of subclinical endometritis cows that did not receive FM treatment (P = 0.09). In conclusion, subclinical endometritis in recipient beef cows resulted in lower P/ET. Though not significant in cows with subclinical endometritis, FM treatment resulted in 14.0% points more pregnancy compared with control.

Haematological Responses following Oestrus synchronisation and superovulation protocols in West African Dwarf Goats

Experiments were performed to evaluate the haematological (erythrocyte and leucocyte parameters) response of West African Dwarf goats following oestrus synchronisation and superovulation protocol. Twenty-four clinically healthy female goats aged 2.34 ± 0.4 years and average body weight of   13.83 ± 0.7 kg was used for the experiment. The goats were divided into two groups. Group I goats was synchronized using Controlled Internal Drug Release (CIDR) for 18 days with the first day of insertion as day 0. On day 16 following CIDR insertion into the vagina, a single dose of 500 IU equine chorionic gonadotropin (eCG) was administered to each doe intramuscularly while group II served as the control was subjected to the same housing and environmental conditions but was not synchronized.   superovulation was induced with porcine follicle stimulating hormone (pFSH) which was injected intramuscularly at a rate of 5mg/kg in reducing doses twice a day at 06.00 h and 18.00 h for 3 days starting from 48hr i.e., 2 days before CIDR removal (day 17). A blood sample of 5 mL was collected by jugular venipuncture of each of the goats before the protocol (Day 0) and at the end of the protocol (Day 18). All erythrocyte parameters evaluated showed a significantly higher value in group II (control) compared to group I post-oestrus synchronisation while total leucocyte count, neutrophil count and neutrophil/lymphocyte ratio values obtained after the protocol were also higher in group I (P &lt; 0.05) compared to group II. It is therefore concluded that oestrus synchronisation and superovulation may elicit stress in West African Dwarf goats and an appropriate antioxidant should be part of the protocol.

Effect of progesterone infused controlled internal drug releasing (CIDR) device and timing of gonadotropin stimulation using P.G. 600 on reproductive success in ewes bred out of season.

Objectives of this study were to determine effects of exogenous progesterone (via controlled internal drug releasing devices; CIDR) in combination with exogenous gonadotropins (PMSG/hCG) use either at CIDR removal or 1 d before CIDR removal to induce estrus and cyclicity and subsequently enhance the proportion of ewes lambing, lambing rate, prolificacy, and days to lambing in ewes bred out of season. Multiparous ewes (n = 414) were randomly assigned to one of four treatments: untreated (U, n = 122), 7 d CIDR (C, n = 97), 7 d CIDR plus P.G. 600 (240 IU pregnant mare serum gonadotropin [PMSG] and 120 IU human chorionic gonadotropin [hCG]) at CIDR removal (CPG0, n = 97), and 7 d CIDR plus P.G. 600 (240 IU PMSG and 120 IU hCG) 1 d before CIDR removal (CPG-1, n = 98). Rams (n = 15) were joined with ewes immediately after CIDR removal and remained with ewes for a 21 d breeding period. Lambing data were summarized for the first 10 days of the lambing season and overall. Categorical data were analyzed using the GLIMMIX procedure of SAS whereas non-categorical data were analyzed using the mixed procedure. Proportion of ewes lambing in the first 10 d was greater (P < 0.05) for CPG0 and CPG-1 ewes compared with C ewes, which was greater (P < 0.0001) compared with U ewes. Overall proportion of ewes lambing was greater (P ≤ 0.0001) in all treatments utilizing CIDR compared with U ewes, but no differences (P ≥ 0.84) due to P.G. 600 were detected compared with C. Lambing rate in the first 10 d was greater (P < 0.05) for CPG-1 than C, with CPGO being intermediate, and all CIDR-treated ewes being greater than U (P < 0.0001). Overall lambing rate increased (P ≤ 0.0001) in all treatments utilizing CIDR compared with U ewes, but no differences (P ≥ 0.76) due to P.G. 600 were detected compared with C. Prolificacy was similar among all treatments both for the first 10 d of the lambing season (P = 0.86) and overall (P = 0.80). Day of lambing in the lambing season was reduced (P ≤ 0.03) for CPG0 and CPG-1 compared with CIDR-treated ewes, which was reduced (P < 0.0001) compared with U ewes (days 10.6, 9.0, 13.4, and 24.4 ± 0.9 for CPG0, CPG-1, CON, and U, respectively). Though timing of P.G. 600 did not influence results, the combination of CIDR and P.G. 600 enhanced the proportion of lambs born earlier in the lambing season, and incorporating a CIDR with or without P.G. 600 enhanced the overall proportion of ewes lambing and lambing rate in out-of-season breeding scenarios.

Effects of temperament on reproductive performance of Bos taurus heifers enrolled in the 7-day CO-Synch + controlled internal drug release protocol.

Cattle temperament significantly impacts production traits such as reproduction. The objective of this study was to assess the effects of temperament on pregnancy rates to fixed-timed artificial insemination (TAI) in Bos taurus beef heifers. A total of 297 Angus influenced heifers from 3 different locations were evaluated for temperament based on chute score and exit velocity on the first day of the estrus synchronization protocol (d-9) and classified by temperament type based on temperament score (calm ≤ 3 < excitable). Pregnancy status was determined by transrectal ultrasonography approximately 40 d after TAI. Hair from the tail switch was collected at d-9 and at d0 (TAI) for cumulative cortisol evaluation. A subset of 43 heifers from location 3 had blood samples collected at all handling events and evaluated for cortisol concentrations. Overall, 71% of heifers were classified as calm whereas 29% as excitable. Pregnancy rates to TAI were reduced (P = 0.042) in excitable heifers compared to calm heifers (36% vs. 55%, respectively). Mean concentration of cortisol in the hair was reduced over time (P < 0.001) from d-9 (3.5 ± 0.3 pg/mg) to d0 (1.74 ± 0.3 pg/mg) in all heifers, regardless of temperament. In addition, excitable heifers had increased circulating concentrations of cortisol when compared to calm heifers in all handling events (P = 0.015). More interestingly, despite of temperament, concentrations of circulating cortisol were reduced as the protocol events progressed, with greater cortisol concentrations on d-9, intermediate on d-3, and lesser on d0 (P = 0.031). Therefore, the present study demonstrates that heifer temperament has negative effects in pregnancy rates to TAI programs. However, according to blood cortisol concentrations, no chronic stress response was detected due to cattle handling for the TAI protocol. In fact, blood cortisol concentration was reduced between the initiation and completion of the protocol, indicating that heifers were acclimated to handing. These results support the adoption of acclimation protocols and proper cattle handling as a strategy to increase fertility of heifers that are exposed to TAI.

PSV-A-1 Estrus Response and Pregnancy Rates of Beef Cows Enrolled in two Fixed-Time Artificial Insemination Protocols, with or without pre-Synchronization

Abstract Pre-synchronization strategies with prolonged exposure to exogenous progesterone have the potential to alter estrus expression and improve fertility in beef cows. The objective of this study was to evaluate the estrus response and pregnancy rate of suckled beef cows enrolled in two fixed-time artificial insemination (TAI) protocols. A total of 1,216 cows (angus-crossed) at 10 locations across VA were enrolled in the study. Within location, cows were ranked by body weight, and days postpartum and randomly assigned to one of two treatments: 1) 7&amp;7 (n = 610), cows were administered prostaglandin F2α (PGF; 25 mg) and a controlled internal drug releasing (CIDR) insert [Day -14], an injection of GnRH (100 μg [Day -7]), PGF injection and CIDR removal [Day 0], and a second injection of GnRH concurrently with TAI 64 ± 2 h later [Day 2]; 2) 7-day CO-Synch+CIDR (7-day; n = 606), cows were administered GnRH (100 μg) and a CIDR insert [Day -7], PGF (25 mg) injection and CIDR removal [Day 0], and a second injection of GnRH concurrently with TAI 64 ± 2 h later [Day 2]. All cows received an estrus alert patch (ESTROTECT) on Day 0 and were evaluated for patch activation at TAI on Day 2. Pregnancy was diagnosed by transrectal ultrasonography between 45 and 65 days after TAI. The percentage of cows exhibiting estrus between Day 0 and 2 was greater (P &amp;lt; 0.001) for 7&amp;7 compared with 7-day cows (72.8% and 55.9%, respectively). However, pregnancy rate to TAI was similar (P = 0.328) between treatments (63.8% and 61.1%, for 7&amp;7 and 7-day, respectively). We conclude that suckled beef cows enrolled in the 7&amp;7 TAI protocol had increased estrus expression, but similar pregnancy rate when compared with cows enrolled in the 7-day CO-Synch+CIDR TAI protocol.

PSIV-A-3 Body Temperature Monitoring Using Subcutaneously and Vaginal Sensors in Grazing Cows

Abstract Body temperature is an indicator of animal health and can be used to detect harmful physiological events in advance of clinical symptoms. Traditionally, body temperature in cattle is determined with a rectal thermometer and requires the animal to be restrained. Although systems to automatically monitor cattle health in confinement operations exist, assessing the real-time temperature of grazing cows is not common. Our object was to demonstrate an integrated sensor network for monitoring pastured cattle body temperature in comparison with temperature measured by a vaginal logger. The integrated sensor network (Mahindra &amp; Mahindra; Mumbai, India) communicates with the data obtained from a subcutaneous temperature sensor (EmbediVet, Livestock Labs Inc.; Pittsburg, PA) to a cloud-based data storage platform. The vaginal temperature was measured by an implantable temperature logger (Micro-T 16-bit; Star Oddi, Iceland). Vaginal devices were inserted into the vagina using a controlled internal drug release (CIDR) cleaned of progesterone. The subcutaneous temperature sensors were surgically implanted through a 2cm vertical incision in the neck. Data from the implantable sensor were transmitted via Bluetooth communication to a solar-powered base station. The subcutaneous sensors and vaginal loggers were deployed on 10 grazing cattle over a period of 6 months. Data from only 4 subcutaneous sensors consistently reported data. Temperature values measured by the subcutaneous sensors had no statistical relationship (P=0.595) with body temperature measured by the vaginal temperature loggers. However, the subcutaneous sensors were able to detect changes in body temperature over time within-animal, indicating that errors in predicting temperature were more likely due to frameshift issues than an inability to track true temperature. Further improvements in data-processing and higher sample size are needed to maximize the usability of this sensor network for monitoring cattle body temperature.

Effect of eCG dose on ovarian haemodynamics, hormonal profiles and prolificacy rate when oestrus was induced during low-breeding season in Beetal goats.

The objectives of the experiment were to determine the effect of two doses of equine chorionic gonadotropin (eCG) in a standard synchronization protocol based on a short-term progesterone (P4 ) priming on ovarian structures and haemodynamics, concentrations of steroid hormones and prolificacy rate when oestrus was induced during low-breeding season (LBS) in Beetal dairy goats. We hypothesized that inclusion of eCG in a short-term P4 priming-based synchronization protocol would increase the blood perfusion to ovarian structures leading to enhance oestrous and ovulatory responses and prolificacy rate in goats. Forty-two multiparous acyclic goats were blocked by body condition and, within block, assigned randomly to receive saline as control (CON), low eCG (L-eCG; 300 IU) or high eCG (H-eCG; 600 IU) dose. Initially, a controlled internal drug release (CIDR) device was placed in the anterior vagina on d -8, followed by removal of CIDR on d -3, concurrent with the administration of PGF2α and eCG according to their respective treatments. Goats were monitored for oestrous response. B-mode and Doppler ultrasonography was performed with 12-h interval, starting from day -3 until natural breeding (day 0), and then on days 5, 10, 15 and 20 post-breeding to monitor follicular and luteal dynamics and blood flow, respectively. Blood was sampled at 0, 12, 24, 36 and 60 h after CIDR removal to quantify plasma concentrations of estradiol-17β (E2 ), whereas plasma concentrations of P4 were assayed at days 5, 10, 15 and 20 after breeding. Pregnancy and prolificacy rates were determined at day 30 and 150 after breeding, respectively. Data were analysed with mixed-effects models, and orthogonal contrasts were used to evaluate the effect of treatment [Con vs. (½L-eCG + ½ H-eCG)] and dose of eCG (L-eCG vs. H-eCG). Data are presented in sequence as CON, L-eCG, H-eCG (LSM ± SEM). The oestrous intensity score (152.9 vs. 182.7 vs. 186.5 ± 15.1; p =.02) was greater in eCG-treated goats as compared to CON. Administration of eCG reduced the intervals to standing oestrus (66.2 vs. 41.8 vs. 48.9 h ± 5.5; p =.05), breeding (70.2 vs. 44.4 vs. 45.4 h ± 4.5; p =.03) and ovulation (84.5 vs. 61.2 vs. 63.4 h ± 6.2; p =.05) compared with CON goats. The mean growth rate of pre-ovulatory follicle was greater (1.11 vs. 1.49 vs. 1.45 mm ± 0.08; p =.01) in eCG-treated goats resulting in an increased diameter of pre-ovulatory follicle (6.27 vs. 7.20 vs. 7.31 mm ± 0.07; p <.01) and corpora lutea (6.75 vs. 8.26 vs. 8.07 mm ± 0.42; p =.04) than CON. The mean follicular blood flow did not differ among treatments; however, the mean luteal blood flow was greater in L-eCG-treated goats (0.81 vs. 1.61 vs. 1.07 cm2  ± 0.12; p =.001). The mean concentrations of E2 (4.03 vs. 5.21 vs. 4.78 pg/ml ± 0.42; p =.04) and P4 (4.85 vs. 6.39 vs. 6.22 ng/ml ± 0.34; p =.04) were greater in eCG-treated goats. The twinning rate did not differ between treatments; nevertheless, prolificacy rate was greater (p =.04) in L-eCG-treated goats. Collectively, our data suggest that the administration of eCG improves the induction of oestrous and ovarian dynamics. Administration of L-eCG enhances prolificacy rate, therefore, a low dose of eCG might be practically beneficial to improve reproduction during LBS in acyclic Beetal dairy goats.