Mufeed A. Alnimer

Estrus Synchronization in Sheep and Goats Using Combinations of GnRH, Progestagen and Prostaglandin F2α

The objective of this experiment was to evaluate the effect of GnRH, progestagen and prostaglandin F(2alpha) on estrus synchronization in sheep and goats. Sixty Awassi ewes and 53 Damascus does were used in the study. The experiment started at the beginning of the breeding season (June/July). The same treatments were applied to sheep and goats as follows: no treatment (CON), 14-day progestagen sponges and 600 IU equine chorionic gonadotropin (S), gonadotropin releasing hormone followed 5 days later by prostaglandin F(2alpha) (GP) and gonadotropin releasing hormone, progestagen sponges for 5 days and prostaglandin F(2alpha) on the day of sponge removal (GSP). None of the ewes in the S group lambed from mating during the induced cycle. A greater lambing rate (p < 0.05) was observed in the GSP group compared with the CON and S groups while the GP group was intermediate. The number of lambs born per lambed ewe was similar among the CON, GP and GSP groups. However, the number of lambs per exposed ewe was greater (p < 0.05) in the GSP than the remaining groups. The induced cycle kidding rate was 77% for all treatments combined. Similar kidding rate were observed among treatments. The numbers of kids born per kidded and exposed doe from mating during the induced estrus were also similar among treatments. Greater numbers of multiple births were observed in the GP and GSP than in the S group. In conclusion, a combination of GnRH, progestagen sponges and PGF(2alpha) can be effective in synchronizing estrus and improving fecundity in sheep and goats. Although the use of GnRH-PGF(2alpha) was effective, the addition of progestagen sponges at the time of GnRH administration appeared to improve reproductive parameters.

Applying variations of the Ovsynch protocol at the middle of the estrus cycle on reproductive performance of lactating dairy cows during summer and winter.

Two modifications of the Ovsynch protocol, GnRH+TAI after PGF(2 alpha) 48 h (CO-48) or 72 h (CO-72), were compared with the original protocol (OVS: GnRH-7 d-PGF(2 alpha)-2 d-GnRH-16 h-TAI) to study their effects on reproductive performance in 785 lactating dairy cows (Holstein Friesian, Bos Taurus). Results showed that more cows (P<0.001) returned to estrus within a week after TAI with CO-48 treatment compared with that in OVS and CO-72 treatments. Pregnancy rates were greater (P<0.001) for the CO-72 cows than those for both OVS and CO-48 treatments and for primiparous cows compared with multiparous cows. Moreover, pregnancy rates were lower in summer compared with those in winter. Pregnancy losses for cows in both CO-48 and CO-72 were greater (P<0.05) than that for cows in OVS treatment. Pregnancy losses were greater in summer (P<0.001) than in winter and for multiparous cows (P<0.001) than for primiparous cows. In conclusion, primiparous and winter-bred cows had greater pregnancy rates and fewer pregnancy losses than those of multiparous cows and summer-bred cows, respectively. Because of the presence of significant treatment, parity, and season interactions, TAI with ovulation synchronization protocols should be tailored according to the season and parity. CO-72 is recommended for primiparous cows but not for multiparous cows, and CO-48 is not recommended for synchronization. Furthermore, cows that exhibited estrus at any time were inseminated to improve pregnancy rates in ovulation synchronization protocols.

Hormonal treatments and the ram effect on synchronised oestrus in Awassi ewes at the beginning of the breeding season

Abstract Eighty‐four Awassi ewes in five groups were used to study the effect of using different hormonal treatments or ram effect on oestrus synchronisation and fertility at the beginning of the breeding season. At the onset of the treatments, gonadotropin releasing hormone‐prostaglandin F2α (Gn‐PG, n = 17) ewes received gonadotropin releasing hormone (GnRH) i.m. followed with prostaglandin F2α (PGF2α) 5 days later. Ewes in the prostaglandin F2α‐prostaglandin F2α (PG‐PG, n = 20) group received two i.m. injections of PGF2α 10 days apart. Ewes in the fluorogestone acetate (FGA, n = 15) group were fitted with FGA intravaginal pessaries, left for 14 days and given an i.m. injection of pregnant mare serum gonadotropin (PMSG). Ewes in hormonal treatments (Gn‐PG, PG‐PG, FGA) and the Close (n = 17) group, were housed in a barn close to the rams’ barn for the last 15 days, while those in the Far (n = 15) group were left in a barn completely separated from rams until the day of mating. Ten fertile rams were introduced 48 h after the last treatments. Plasma progesterone (P4) concentrations were similar at the onset and at the last day of treatments for ewes in the five groups. On Days 8 and 11 (Day 0 = day of last treatment) a significant increase (P < 0.05) in P4 level was observed in the Gn‐PG and PG‐PG compared with the Close and Far groups. Plasma P4 remained higher in the Gn‐PG and PG‐PG, compared to the other groups through Days 17–20 post‐treatment. The average oestrus response was 80% and similar in all groups. Pregnancy rate based on plasma P4 concentrations on Days 17 and 20 post‐treatment were lower in the Close than other groups. The proportion of ewes observed in oestrus in the hormone treated groups tended to be greater (P < 0.1) than that in the non‐hormone treated (Close, Far) groups. Pregnancy rate, based on P4 concentrations and lambing rate, were significantly greater (P < 0.05) in the treated groups than that in the non‐treated groups, while lambing rate from ewes rebreeding was similar. Results indicate that Awassi sheep maybe synchronised using either GnRH‐PGF2α program or two injections of PGF2α 10 days apart as well as progestagen treatment, but with lower number of days required for synchronisation. Similar pregnancy and first lambing rates were observed in the treated groups and Far group, which may be due to the sudden introduction of rams to the last group, but the Close group was still low.

Pregnancy-specific protein B (PSPB), progesterone and some biochemical attributes concentrations in the fetal fluids and serum and its relationship with fetal and placental characteristics of Iraqi riverine buffalo (Bubalus bubalis)

This study was carried out to demonstrate the pregnancy-specific protein B (PSPB), progesterone and some biochemical parameters concentrations in amniotic fluid, allantoic fluid and fetal serum collected from slaughtered Iraqi riverine pregnant buffaloes at three different months of gestation (6th, 7th and 8th). Ten out of 22 adult buffaloes of 4.6 ± 0.97 years old were used in this study. The buffaloes were mated naturally by monitoring the estrus cycles via appearance of vaginal fluids and mounting by bulls. Pregnancy was checked for these buffaloes by non-returning to estrus for three estrus cycles and assured by rectal palpation on day 61 post-mating (PM). Buffaloes were slaughtered at three different periods of gestation (three at 6th month, four at 7th month and three at 8th month of gestation) to verify the progesterone and PSPB as well as some blood attributes levels (glucose, cholesterol, total protein, albumin, globulins and albumin: globulins ratio) in amniotic fluid (AF), allantoic fluid (LF) and fetal serum (FS). Progesterone was higher (P<0.01) in LF at the 8th month of gestation and lower in FS during the 7th and 8th months of pregnancy. PSPB concentrations were greater in FS (6th and 8th months in particular) than in both AF and LF. The overall mean of cholesterol concentration was higher in FS (P<0.05) followed by AF and LF that had the lowest concentration. The FS exhibited higher total protein during the three gestation periods. Most of fetal and placental measurements increased as the pregnancy advanced. In conclusion, these results described, for the first time, the PSPB and progesterone concentrations and blood characteristics in fetal fluids and serum in water riverine buffaloes during different stages of pregnancy. Progesterone concentrations were greater in allantoic fluid than in other fluids. In contrast, PSPB and other blood attributes were higher in fetal serum than other fluids of Iraqi riverine buffaloes. These findings reflect the changes in hormones, proteins and other metabolites during different gestation periods.

Effect of protected methionine supplementation on milk production and reproduction in first calf heifers

Abstract. Sixty Holstein heifers (30 days in milk) were used to examine the effects of protected methionine on milk production, milk composition and reproduction performance up to 100 days post-partum. Heifers were randomly divided into two dietary treatment groups (30 each) receiving either 14 or 16 % crude protein. Heifers of each treatment group were assigned into three subgroups with a daily supplementation of 0, 15 or 25 g/hd/d of rumen protected methionine. Diet fed was a total mixed ration consisting of fresh alfalfa, corn silage and a concentrate mixture. In addition, alfalfa hay was offered ad libitum during the whole experimental period.

Treatment with hCG 4 or 6 days after TAI to improve pregnancy outcomes in repeat-breeding dairy cows

A study was conducted to evaluate the effect of human chorionic gonadotropin (hCG) administration 4 or 6 days after timed AI (TAI) on P4 concentration and pregnancy outcomes in repeat breeding dairy cows. All cows were treated by Cosynch protocol before being assigned into 3 groups: CON (n=139): did not receive hormonal treatments; D4 (n=136): received 1500 IU hCG 4 days post TAI; and D6 (n=131): received 1500 IU hCG 6 days post TAI. Plasma P4 concentration was evaluated on Day of hCG and 12 days post TAI. Pregnancies per AI (P/AI) on Day 45 were greater for D6 (38.9%) than CON (30.9%) groups. Pregnancy losses (PL) were lower for D6 (15.0%) and D4 (26.7%) than CON (37.7%) groups. Treatment by season revealed a greater P/AI and lower PL for D6 (30.3% and 18.2%) and D4 (33.3% and 31.0%) than CON (19.2% and 58.3%) groups during summer, while P/AI was greater for D6 (57.1%) than D4 (30.6%) and CON (37.9%) groups during winter. Treatment by parity indicated a greater P/AI for D4 (46.4%) and D6 (31.6%) than CON (15.8%) groups within primiparous cows. Pregnancy losses were lower for D6 (15.1%) than CON (36.5%) groups within multiparous cows while D4 tended to be lower (13.3%) than CON (50.0%) groups. Plasma P4 concentration on Day 12 post TAI was higher for treated than for CON groups. Applying hCG 6 days after TAI was beneficial in improving P/AI either in summer or winter as a result of reducing PL and increasing P4 concentration.

The effect of a progesterone (P4) intravaginal device (CIDR) on resynchronisation of oestrus and embryonic loss in previously timed inseminated dairy heifers.

A study was done to evaluate the effect of using progesterone (P4) intravaginal device (CIDR: controlled internal drug-releasing dispenser) to synchronise the return to oestrus of previously timed inseminated (TAI) dairy heifers, and to evaluate embryo survival and pregnancy rate (PR) in the return to oestrus heifers. At the onset of the artificial insemination (AI) breeding period (day -9), heifers were randomly assigned into two groups (treated group CGPG, n = 79) and (control group GPG, n = 83). Every heifer in both groups was injected with gonadotropin-releasing hormone (GnRH) agonist and prostaglandin F2-alpha (PGF2α) as follows: GnRH on day -9; PGF2α on day -2; GnRH and TAI on day 0. Heifers in both groups received TAI within 30 min after the second GnRH injection. Artificial insemination at first breeding was conducted for all heifers during 55 days from day 0. On day 14 after timed insemination, every heifer in the CGPG group received CIDR device for 6 days. Within 3 days after CIDR removal, more heifers in CGPG group showed oestrus within 1.9 days compared to heifers that showed oestrus within 2.9 days in the control. Within 10 days after CIDR removal, more heifers in the CGPG group showed oestrus within 2.4 days compared to heifers that showed oestrus within 6.7 days in the control. PRs on days 30 and 55 were not different between both groups, while PR on day 55 during September were higher (P = 0.032) in CGPG group (58.0%) than GPG group (37.0%). In addition, PR from first to second AI was higher (P = 0.037) for CGPG group (79.8%) than for GPG group (65.1%) but it was similar after that. Pregnancy losses between days 30 and 55 tended to be lower (P = 0.089) for the CGPG group (12.7%) compared to 25.1% for the GPG group. Interval between first and second AI was lower (P = 0.052) for the CGPG group (27.5 ± 1.6 days) compared to 31.6 ± 1.3 days for heifers in the GPG group but no differences were detected for intervals from second to third AI and from third to fourth AI between the two groups. Number of services per pregnancy was not different between CGPG and GPG groups. Results indicate that the CIDR device improved synchronisation to return to oestrus and increased PR to first AI during high temperature months by reducing embryonic losses.