• Journal of Embryo Transfer
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• v.29 no.2
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• pp.149-155
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• 2014

The present study was designed to observe the oestrus responses in the indigenous ewe induced by cloprostenol sodium manufactured by two different companies ($Ovuprost^{(R)}$, BOMAC, Newzealandand $Prostenol^{(R)}$, Techno, Bangladesh). Twelve local ewes were divided into 3 groups (n= 8). The ewes in Group I and II were induced by intramuscular injection of $100{\mu}g$ (0.4 ml) of cloprostenol sodium ($Ovuprost^{(R)}$ and $Prostenol^{(R)}$), respectively. The $2^{nd}$ injection in each group was given at 9 days apart. The ewes in Group III were kept as control for observing natural oestrus characteristics and comparing the responses with induced oestrus. Hundred and 75% ewes showed oestrus following $2^{nd}$ injection of $Ovuprost^{(R)}$ and $Prostenol^{(R)}$, respectively. The average time of onset of oestrus following $1^{st}$ and $2^{nd}$ injection of $Ovuprost^{(R)}$ and $Prostenol^{(R)}$ were $50.5{\pm}3.5$ vs $48.0{\pm}0.0h$ and $49.9{\pm}1.9$ vs $49.5{\pm}1.7h$, respectively. There was no significant difference between the two types of cloprostenol sodium group on the onset of oestrus. The average duration of oestrus was $27.5{\pm}0.7$ vs $27.5{\pm}0.0h$ and $25.9{\pm}3.3$ vs $24.2{\pm}0.3h$ in $Ovuprost^{(R)}$ and $Prostenol^{(R)}$ treated ewes, respectively. For natural oestrus, the duration of oestrus was $25.2{\pm}3.3h$. There was no significant difference among the cloprostenol sodium produced by two different companies and natural oestrous ewes on the duration of oestrus. The higher percentages of cornified cells were present in induced oestrus (90 and 85%) compared with natural oestrus (80%), although there was no significant difference among them. The pregnancy rates were 75, 66.7 and 100% in $Ovuprost^{(R)}$, $Prostenol^{(R)}$ and natural oestrous ewes, respectively. The above results indicate the suitability of using cloprostenol sodium for synchronization of oestrus in indigenous ewes in Bangladesh.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1673-1685
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• 2019

Objective: To evaluate the efficacy of treatments based on gonadotrophin-releasing hormone (GnRH), GnRH-prostaglandin $F2{\alpha}$ ($PGF2{\alpha}$), and/or intense exposure to novel rams to induce fertile estrus without the use of steroid hormones in seasonally anestrous Suffolk ewes. Methods: In the first experiment, ewes were treated with one injection of GnRH, two injections of GnRH administered 7 days apart, or a sequence of GnRH-$PGF2{\alpha}$-GnRH (GPG). In the second experiment anestrous ewes were exposed, for 36 days starting on the day of weaning, to groups of four rams of three different breeds that were alternated every day. Besides exposure to the male effect (ME), the ewes were injected with saline solution (ME group, n = 20), with GnRH (ME-GnRH group, n = 20) or with a sequence of GnRH-$PGF2{\alpha}$-GnRH (ME-GPG group, n = 20). The rams used for male-effect were fitted with aprons to prevent mating, and ewes detected in estrus were bred to selected fertile rams. Ovarian activity was monitored by progesterone determinations in both experiments. Results: In the first experiment sustained induction of ovarian activity was not achieved and no ewe was detected in estrus. In the second experiment induction of sustained ovarian activity was achieved in all groups. Most of the ewes were detected in estrus, 76.7% of the ewes were mated during a 36-d breeding period and 71.7% of all the ewes became pregnant during that period. No significant differences between groups were found for any of these variables. However, estrus detection efficiency was higher in the ME-GnRH group than in the ME group (p<0.05). Conclusion: An intense male-effect, that included the continuous presence and frequent alternation of several rams of different breeds, was sufficient to induce ovarian activity and fertile estrus in Suffolk ewes during the period of deep anestrus without the use of hormones, although addition of GnRH improved the efficiency of estrus detection.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.4
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• pp.515-518
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• 2003

Six mature purebred Angus cows ($3.5{\pm}1.5$ years of age, $631.36{\pm}8.63kg$), three pregnant ($250{\pm}7$ days pregnant) and three non-pregnant and eight mature Suffolk ewes ($5{\pm}1.2$ years of age, $68.18{\pm}2.3kg$) four pregnant $115{\pm}5$ days pregnant) and four nonpregnant were utilized in a five-day metabolic trial to determine the effects of gestational status (pregnant vs. non-pregnant) on apparent absorption and retention of copper (Cu) and zinc (Zn). Animals were selected based on body weight, age, and gestational status, and randomly assigned to metabolic crates for total fecal and urine collection. Animals were allowed to acclimate to their new environment for seven days. Pregnant and non-pregnant cows and ewes were then paired (within a species) by body weight and pair-fed throughout the 5 day collection period. Copper and Zn intakes were similar for pregnant and non-pregnant animals within a species. Apparent absorption of Cu (p<0.06) and Zn (p<0.04) were higher in pregnant cows relative to non-pregnant cows. Pregnant cows also had a higher apparent retention of Cu (p<0.05) and Zn (p<0.06) relative to non-pregnant cows. Pregnant ewes had a higher (p<0.01) apparent absorption and retention of Zn compared to non-pregnant ewes. However, apparent absorption and retention of Cu were similar for pregnant and non-pregnant ewes. These data indicate that certain physiological and/or metabolic parameters are altered in pregnant cows and ewes consuming an alfalfa-based diet that enhance the apparent absorption and retention of certain trace minerals.

• Journal of Animal Science and Technology
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• v.59 no.7
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• pp.13.1-13.6
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• 2017

This study was conducted to investigate the behavioral and physiological changes of heat stressed Corriedale ewes exposed to water deprivation. Nine Corriedale ewes (average $BW=45{\pm}3.7kg$) were individually fed diets based on maintenance requirements in metabolic crates. Ewes were assigned into three groups (9 sheep per treatment) according to a $3{\times}3$ Latin square design for 3 periods with 21-d duration for each period. The control (CON) group was given free access to water, 2 h water deprivation (2hWD), and 3 h water deprivation (3hWD) following feeding. No differences were found in fecal excretion frequency, standing frequency (number/d), and sitting frequency among the groups (p > 0.05). Measurements of standing duration (min/d) and urine excretion frequency (number/d) showed a significant decrease whereas sitting duration (min/d) showed a significant increase in the 2hWD and 3hWD groups when compared with the CON group (p < 0.05). Fecal score and heart rate (number/min) were not different among the groups (p > 0.05). However, respiratory rate (number/min) and panting score were found to be significantly higher in the 2hWD and 3hWD groups than in the CON group (p < 0.05). It is concluded that water deprivation following feeding intensifies physiological heat stress related indicators such as respiratory rate and panting score and changes behavioral parameters such as water intake and urine excretion frequency in heat stressed ewes. Daily adaptation to the extreme environmental conditions may occur actively in ewes.

• Asian-Australasian Journal of Animal Sciences
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• v.8 no.5
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• pp.419-425
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• 1995

Twenty growing female Damascus (Shami) goats and twenty growing Chios ewes of two mating ages (10 and 12 months) were used to study the effect of mating age (MA) on reproductive performance (RP). In addition to (RP), The growth, milk production and nutrient requirements were also evaluated. A complete random design in a $2{\times}2$ factorial was used, with (MA) and species as the main factors. (MA) had no effects on (RP), milk production and mortality. No significant difference (p > 0.05) were observed between (MA) or between species, for age at kidding/lambing (K/L). Sheep reached puberty earlier than goats. Average age (months) at conception and at (K/L) was 15.8; 20.8 and l7.0; 22.0 for sheep and goats respectively. Body weight (BW), rather than age was the most important factor determining puberty. Both goats and ewes conceived when they reached about 67% of their mature (BW) for goats and 85% for ewes. Sheep grew faster than goats, but the latter had higher twinning (67.8% versus 25%). Chios sheep were suitable for meat and Shami goats for dairying or dual purpose systems. Nutrient requirements for growth of goats and ewes were similar with an average DM-intake of about 4% (BW); 12-13% CP and 65-69% TDN (DM-basis) of the total ration. It is recommended to breed Chios ewes at a (BW) of at least 50 kg and Shami does at 38 kg, irrespective of their age.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.4
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• pp.333-339
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• 1991

Eighty-two ewes of Balochi breed, two to four years of age were used in a completely randomized design to study the effect of winter supplementation on their performance in Kalat area of Balochistan and randomly divided into two groups of 40 and 42 animals. Two treatments (T1 and T2) studied were : 250 gm/animal/day of a 50 : 50 mixture of cottonseed cake and barley grain fed from Oct. 20 to Dec. 18, 1988 plus grazing and 500 gm/animal/day of the same feed mixture fed from Oct. 9 to Dec. 18, 1988 in addition to grazing. Lucerne hay and wheat straw in a 50 : 50 ratio were provided to all the ewes for a period of one month from Jan. 6, 1989 @ 320 gm/animal/day to sustain them in severe winter. Same feeding levels to the same ewe groups were again fed from Mar. 1 to May 27, 1989. Three breeding rams stayed with the flock from Nov. 1 to Dec. 13, 1988. Lambing took place from Apr. 2 to May 12, 1989. Conception, lambing and mortality percentage was found different (P<.05) between T1 and T2 (12.5 vs 14.8 kg). The ewes on T2 maintained higher body weights throughout winter than the ewes on T1. The results are suggestive of improvement in conception rate with winter supplementation (flushing) and decrease in ewe mortality. Late-gestation and early-lactation supplemental feeding of ewes results in increases in weaning weights of their lambs.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1117-1123
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• 2012

The effect of duckweed (DW) supplementation was evaluated on dry matter intake (DMI), presence and duration of estrus, percentage of ewes repeating estrus and pregnancy rate, as well as the concentration of progesterone ($P_4$) in multiparous crossbred ewes from Pelibuey, Dorper, and Katahdin breeds, fed with Taiwan grass hay (TWH). Eighteen ewes with $39.7{\pm}4kg$ mean body weight, kept in individual pens, were randomly assigned to one of the following treatments: $T_1$: TWH, $T_2$: TWH plus 200 g DW, $T_3$: TWH plus 300 g DW. The ewes were synchronized with 40 mg fluorogestone acetate (FGA) and 400 UI equine chorionic gonadotropin (eCG). Data were analyzed as a completely randomized design using the GLM procedure. DW supplementation had no effect on dry matter intake (p>0.05); however, a slight decrease of TWH intake was observed as DW supplementation increased. No differences (p>0.05) were found in the beginning of estrus, percentage of ewes presenting it, its duration, or pregnancy rate. There were no differences (p>0.05) on $P_4$ concentration among treatments, or $treatment{\times}period$ interaction (p>0.05). However the period was significant (p<0.01), since the $P_4$ levels increased as time increased after the removal of the FGA device and eCG application.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.6
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• pp.785-788
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• 2012

The aim of the present study was to clarify the effect of kisspeptin-10 on LH secretion in prepubertal ewes. In experiment 1, prepubertal ewes fitted with indwelling jugular catheters were randomly assigned to receive 0, 0.5, 1 or 2 mg of kisspeptin-10 dissolved in saline, and serial blood samples were collected at 15-min intervals for 180 min to analyze the response curves of LH after injection. In experiment 2, prepubertal ewes fitted with indwelling jugular catheters were injected with 0 or 1 mg of kisspeptin-10 dissolved in saline and the injection was repeated 3 times at 1 h interval and serial blood samples were collected at 15-min intervals for 210 min to analyze the response curves of LH after injection. The results showed that single intravenous administration of 0.5, 1 and 2 mg of kisspeptin-10 all could significantly increased LH secretion in prepubertal ewes, and the effect of 1 and 2 mg of kisspeptin-10 on LH secretion was higher than that of 0.5 mg group. The results also showed that repeated intravenous administration of kisspeptin-10 could effectively increase LH secretion and repeated administration did not influence the effect of kisspeptin-10 on LH secretion in prepubertal ewe. In conclusion, the present study indicated that single or repeated intravenous administration of kisspeptin-10 could effectively increase LH secretion in prepubertal ewes.

• Journal of Animal Science and Technology
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• v.65 no.5
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• pp.922-938
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• 2023

The current study was designed to evaluate the effect of sequential low and high dietary linseed oil (LO; as omega-3 enriched fatty acid; FA) before and post insemination, respectively, on different plasma variables of ewes. Fat-tailed Qezel ewes were assigned randomly to be fed a diet enriched with 3% LO (n = 30) or the saturated FA (SFA; n = 30) three weeks before insemination (Day 0). The lipogenic diet supplemented with 6% LO or SFA was fed after insemination until Day +21. The control ewes were fed an isocaloric and isonitrogenous diet with no additional FA during the study. Estrus was synchronized by inserting a vaginal sponge (Spongavet^®) for 12 days + 500 IU equine chorionic gonadotropin (eCG; Gonaser^®), and ewes were inseminated via laparoscopic approach 56-59 h after eCG injection. The size of ovarian structures was assessed by transvaginal ultrasonography at -21, -14, -2, 0, and +10 days. Blood samples were collected weekly to measure the plasma's different biochemical variables and FA profile. Treatment did not affect the amounts of glucose, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, interleukin-10, interleukin-2, and non-esterified FA (p > 0.05). Conversely, concentrations of triglyceride, cholesterol, tumor necrosis factor-alpha, and insulin-like growth factor-1 were higher in SFA-fed ewes relative to control animals (p < 0.05). LO feeding resulted in greater amounts of n-3 FA isomers in plasma, while higher amounts of stearic acid were detected in SFA fed group 0 and +21 (p < 0.05). The number of ovarian follicles and corpora lutea also were not affected by treatment. Other reproductive variables were not affected by treatment except for the reproductive rate. It seems that LO or SFA feeding of fat-tailed ewes peri-insemination period was not superior to the isocaloric non-additional fat diet provided for the control group during the non-breeding season.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1039-1048
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• 2007

Two experiments were conducted to determine whether leptin is a metabolic signal for gonadotropin secretion in ewes. In the first experiment, twenty-eight cyclic Chal ewes were assigned randomly to an energy restricted, no leptin group (ERNL) (60% of maintenance; n = 14) and an energy normal, no leptin group (ENNL) (100% of maintenance; n = 14) for 71 days (6 estrous cycles). Estrus was synchronized with seven consecutive injections of $PGF_{2{\alpha}}$ Biweekly, body weight (BW) and body condition score (BCS) were determined and blood samples were collected to measure plasma leptin concentration. Blood samples were also taken to determine plasma progesterone concentration twice weekly. After each PG injection from the second injection to the end of experiment, four ewes were selected and blood samples were collected at 20 minutes and at hourly intervals for 3 h to detect plasma LH and FSH concentration. In the second experiment, after the ceasing of the estrous cycle caused by energy restriction, six acyclic ewes were selected and randomly allotted to two groups (n = 3) and received the following treatment for four days. Ewes in an energy restricted, leptin group (ERL) were fed with a ration which provided 60% of maintenance energy requirements and intravenously injected with $4{\mu}g$ leptin/kg BW daily. Ewes in an energy excess, no leptin group (EENL) were fed with a ration that provided 180% (120%+60%) of maintenance energy requirements and intravenously injected with 1 ml saline daily. In both groups, blood samples were collected at 20 minutes and at hourly intervals for 3 h before feeding on d 0 and d 5, and for 3 h before and after injections as above on d 2 and d 4 to detect plasma LH and FSH concentration. In the first experiment, BW and BCS from the $2^{nd}$ estrous cycle, and leptin from the $3^{rd}$ estrous cycle to the end of the experiment significantly (p<0.05) decreased. In ERNL ewes, mean plasma concentrations of FSH significantly (p<0.01) decreased from the $4^{th}$ estrous cycle to d 71 and LH pulsatile secretion was suppressed on d 71, so that, mean plasma concentrations of LH (p<0.05), LH pulse frequency (p<0.01) and LH pulse amplitude (p<0.05) significantly decreased. In the second experiment, injection of leptin significantly increased mean circulating concentrations of LH (p<0.05), LH pulse frequency (p<0.01), LH pulse amplitude (p<0.05) and mean circulating concentrations of FSH (p<0.01) and leptin (p<0.01). High energy intake significantly (p<0.05) stimulated pulsatile secretion of LH and leptin secretion (p<0.01), but non-significantly increased plasma FSH concentration. The results of this study indicate that leptin is a metabolic signal for the GnRH-LH/FSH axis in feed-restricted fat-tailed ewes.