Effects of increased ambient temperature and supplemental altrenogest prior to pregnancy establishment in gilts

Heat stress (HS) mitigation strategies are critically needed to combat the substantial economic effects on animal agriculture. The manifestations of seasonal infertility include delayed puberty onset, reduced conception rates, decreased litter size, and increased wean to estrus interval. To assess the effects of HS during early gestation and evaluate a benefit of supplemental altrenogest (ALT) as a mitigation strategy, thirty crossbred post-pubertal gilts (157 ± 11 kg) were subjected to estrous synchronization via 14 d oral administration of ALT. Artificial insemination during estrus was performed and gilts were then placed into one of four treatment groups; heat stress (HS; 35 ± 1 οC for 12h/31.60 ± 1 οC for 12h) with (HSALT, n = 7) or without (HSCON, n = 7) 15 mg/d ALT supplementation or thermal neutral (TN; 20 ± 1 οC) conditions with (TNALT, n = 8) or without (TNCON, n = 8) 15 mg/d ALT supplementation until 12 d post-estrus (dpe). Administrating ALT occurred at 0600 h from 3-12 dpe and rectal temperatures (TR) and respiration rates (RR) were recorded. Blood was collected via jugular venipuncture on 0, 4, 8 and 12 dpe. Gilts were euthanized humanely at 12 dpe followed by collection of ovarian tissue, and uterine flushing for conceptus collection. In HS compared to TN gilts, RR and TR were increased (P < 0.01) but unaffected by ALT supplementation. Feed intake (FI) was reduced (P < 0.01) by HS but unaltered by ALT treatment. Corpora lutea (CL) weight was reduced (P < 0.01) in HSCON gilts when compared to TNCON and HSALT gilts despite progesterone (P4) concentrations in serum and luteal tissue not being affected by treatment (P ≥ 0.10). CL diameter was reduced (P ≤ 0.05) in HSALT gilts compared to other treatments. Interleukin-1β (IL1B) uterine flush concentration was not affected (P > 0.20) by environment or ALT supplementation, although moderate (P = 0.06) interaction between environment and ALT existed, as IL1B concentration in TNALT was increased (P = 0.03) compared to TNCON gilts. While environment did not affect conceptus development (P = 0.90), ALT supplementation advanced conceptus elongation (P < 0.01). Collectively, these data demonstrate that HS may affect luteal development prior to pregnancy establishment, and ALT increases conceptus elongation by12 dpe.

Estrous synchronization and fertility of cross-bred dairy cows using prostaglandin F2α and gonadotropin releasing hormone

A comparative hormonal study of prostaglandin, gonadotropin releasing hormone and their combination was conducted on 30 randomly selected cross-bred dairy cows of SEMEX project for artificial insemination in Hillat Kuku, Khartoum North, Sudan. The study attempts to determine the response of the animals to hormonal induction and synchronization of estrous as well as fertility following fixed time artificial insemination. Three treatment groups of 10 cows each were undertaken. Groups 1, 2 and 3 involved administration of prostaglandin F2α (PGF2α), gonadotropin releasing hormone (GnRH) and a combination of PGF2α + GnRH, respectively. Descriptive statistical analysis was performed. The results revealed that all the three protocols induced and synchronized estrous were almost synchronous in all the treated groups. However, protocol 3 revealed a significantly (p<0.05) better result of 70% pregnancy rate compared to other two protocols that equally provided 50% pregnancy rates. The study resolves that protocol 3 be highly recommended to change the mindset of farmers about the spread of reproductive technology in Sudan. Protocols 1 and 2 provided acceptable pregnancy rates that can be enhanced with the improvement of management.

PSVIII-16 Effect of estrous synchronization with natural service or fixed-timed artificial insemination with conventional or gender-skewed semen in beef females

Reproductive efficiency is critical for profitability, and age at weaning critically impacts weaning weight. The objective was to evaluate estrous synchronization and/or AI with conventional (CON) or gender-skewed (SEXED) semen on calving distribution. Beef females (n=1,620) were either 1) synchronized (7-CIDR:Syn) or not synchronized (Nonsyn) and mated to bulls, 2) synchronized (7-d CIDR) and mated to bulls (SynNS) or artificially inseminated (SynAI), or 3) synchronized (7-d CO-Synch plus CIDR) and AIed with CON or SEXED semen. Calving distribution and gender were determined at birth and were analyzed using the GLIMMIX procedure in SAS. Synchronization resulted in more calves born from d1 to 14 (P &lt; 0.01; 62% vs 47%) of the calving season. There was no differences (P = 0.31) between Syn and Nonsyn in the percent of calves born after d21, but between d22 and 42, more (P = 0.04) calves were born in the Nonsyn group. A greater proportion (P &lt; 0.02; 46% vs 38%) of calves were born in SynNS between d1 and 14 compared to SynAI. There was no difference between treatments (P &gt; 0.12) from d1 to 42, but more calves were born for SynAI after d43. With SEXED semen, there were no differences (P &gt; 0.14) between CON and SEXED for the proportion of calves born from d1 to 14 or d1 to 21; however, more of the desired gender were born in the SEXED group during d1 to 14 of the calving season (P &lt; 0.01; 84% vs 68%). More total calves were born from d22 to 42 in the SEXED group compared to the CON group (P &lt; 0.05; 49% vs 33%). In summary, synchronization increased the proportion of females that calved early in the calving season, and SEXED semen increased the proportion of the desired gender born early in the calving season.

257 Awardee Talk: Pursuit of Novel Factors that Regulate Ovarian Follicular Function

As follicles grow, theca cells (TC) and granulosa cells (GC) must proliferate with minimal differentiation while thecal vascularization increases so that follicles do not prematurely ovulate or luteinize before the oocyte is fully mature. In the early 2000s we used Affymetrix microarrays to discover several unique genes involved in ovarian follicular development. Thrombospondin and fibroblast growth factor (FGF) 2 receptor genes were stimulated by IGF1 in porcine GC. We compared GC gene expression in bovine cystic versus normal follicles and discovered several novel genes including Indian hedgehog protein (IHH), FGF9, brain ribonuclease (BRB), and G protein-coupled receptor 34 (GPR34), leading to identification of roles for these proteins in ovarian follicular development. During the past 10 years, follow-up TC microarray and mechanistic studies have identified FGF9 control of cell cycle proteins, tight junction proteins, and microRNA 221 (MIR221), and that the mitogenic and steroidogenic responses to the major trophic hormones of the ovary (including IGF1, LH and FSH) are altered by overexpression of MIR221 in GC. In addition, we discovered that: 1) FGF9 stimulates GC and TC mitosis while inhibiting steroidogenesis; 2) FGF9 induces E2 transcription factor (E2F)-1, E2F-8 and cyclin D1 (CCND1), and that both IGF1 and vascular endothelial growth factor-A (VEGFA) synergize with FGF9 to further induce E2F8 and CCND1 mRNA; 3) FGF9 induces the nuclear protein UHRF1; and 4) an E2F inhibitor blocks the stimulatory and inhibitory effects of FGF9 on GC proliferation and steroidogenesis, respectively, and down-regulates UHRF1 mRNA and up-regulates VEGFA mRNA. Thus, aberrant production of FGF9 and the factors it induces/inhibits may lead to vascular dysfunction and ovarian disorders such as ovarian cysts. With additional research, knowledge about these newly identified factors may be used to help the livestock industry improve reproductive efficiency via new treatments for estrous synchronization, superovulation and cystic ovaries.

Serum Progesterone profile of pregnant Ettawa crossbred does at day-0, -21, -42, -63 and -84

This study aimed to determine the progesterone concentrations of Ettawa crossbred does at day-0, -21, -42, -63, and -84 after mating. Five Ettawa crossbred does were injected with PGF2α twice with an interval of 11 days for estrous synchronization followed by natural mating on day-3 after the second PGF2α injection. Blood was collected through the jugular vein for the measurement of serum progesterone concentrations using ELISA, whereas pregnancy was diagnosed at 90 days after mating by abdominal palpation. The results showed that all does were on estrus onthethird day after the second PGF2α, three of them diagnosed to be pregnant following mating. The progesterone concentration at day-0 was 1.52 ± 0.33 ng/mL, increased (p <0.05) to 7.08 ± 1.02 and 5.50 ± 2.82 ng/mL at day-21 and day-42, and increased (p <0.05) again to 12.01 ± 5.30 and 12.04 ± 0.30 ng/mL at day 63 and day 84, respectively. There was no significant difference in progesterone concentrations between day 21 and day 42 and between day 63 and day 84. It could be concluded that there was a biphasic increase of progesterone concentrations of the pregnant Ettawa crossbred does, i.e. from day-0 to day-21/day-42 and from day-21/day-42 to day-63/day-84.

Evaluation of Failure of Oestrus Synchronization and Mass Insemination in Conception Rate of Dairy Cows in Silte Zone

The objective of this study was to evaluate failure of oestrus synchronization and mass insemination in the conception of dairy cattle in Silte zone. To evaluate the mechanism of the failure of OSMI conception rate we have collected (HF, jersey, and HF×Boran breed semen) from the three districts and evaluated their quality in NAGII laboratory thereafter bought 1000 qualified HF semen straw and distributed in the 3 districts. 150 cows were brought by farmers for services, and from those cows 130 cows were fulfil the precondition for this program and injected them with 2 ml of PGF2 alpha hormone. Among the 130 injected cows, 72 (55.38%) of them were responded from day 2 up to day 3 after hormone treated and then inseminated them. The lower percentages of conception rate which was observed in this study were associated with low number of AIT and mass number of cows provided during OSMI program, lack of awareness about heat detection, lack of inseminator equipment and cows did not properly managed after hormone and semen administered as we evaluated. As a result, the quality of semen in Dalocha and Sankura districts was facing with quality problem. We have checked the AITs efficiency through placing six cow per AIT thereafter they inseminated them. As a result, there was no AIT efficiency difference on conception rate based on their working experience in this study. Generally, there is a great need of skilled and experienced technician and capacity building of farmers in heat detection, husbandry practices, and good handling practice of semen in the office and improvement strategy. Therefore, improvement in facilities and management should be necessary before implementing an effective estrous synchronization and mass artificial insemination programs.