Effect of early weaning and hormone treatments on induction of estrus, conception and lambing of fall-lambing Karakul ewes.
نویسندگان
چکیده
The effects of early weaning and exogenous hormones on postpartum estrus, conception and lambing performance were evaluated with 124 fall-lambed Karakul ewes. The broad outline of the experiment consisted of two lactation periods (nursing for 48 hr or 60 days postpartum) and four hormone treatment groups as follows: (1) a single injection of 2 mg estradiol-17/3 on day 4 postpartum and on the same day a silicone rubber implant impregnated with 375 mg progesterone was implanted for 14 days, (2) same as (1) but 36 hr after withdrawal of implants a single injection of 700 IU PMS was given, (3) same as (2) but 16 days after the first injection of PMS another 700 IU PMS was injected, (4) untreated controls. During the first 60 days after lambing, estrus was monitored by use of fertile rams. Neither suckling nor hormone treatment had significant effects on interval to first estrus in days (within 60 days postpartum) or percentage of ewes that exhibited estrus. Ewes in the early weaned group required an average of 189.3 days between lambings as compared with 193.7 days for ewes in the late weaned group (P<.05). Hormone treatments did not have a significant effect on the interval between Iambings. Percentage of ewes that lambed after experimental treatments was higher (P<.05) for the early weaned group as compared to the late
منابع مشابه
Impacts of supplemental arginine on the reproductive performance of fall lambing ewes.
In sheep, embryonic and fetal death during pregnancy can account for 25% to 50% of the total number of corpora lutea (and thus potential embryos). The objective of this study was to determine the effects of injectable and oral Arg supplementation provided for 14 d postbreeding on the reproductive performance of naturally stimulated fall lambing ewes. Rambouillet ewes ( = 210) were exposed to ra...
متن کاملLambing performance of Morlam and Dorset ewes under accelerated lambing systems.
Two accelerated lambing systems, Morlam using Morlam sheep (USDA, Beltsville 1966 to 1975) and Camal using Dorset ewes (Cornell 1978 to 1981), were evaluated for first lambing ages, interlambing intervals and conception probabilities. Morlam ewes were continuously exposed to rams over the year, while Camal Dorset ewes were exposed every other month. Morlam lambs were mated as early as 367 d of ...
متن کاملEffect of short-term progestogen treatment on induction of estrus and lambing in anestrous ewes.
Two-hundred-fifty-six crossbred and Targhee ewes which lambed in February and March were randomly assigned to a 38or 73-day postpartum weaning group and within weaning group to a control, an 8or a 16-day progestogen treatment. Treatment was an intravaginal progestogen pessary for 7 days after weaning or for 15 days beginning 8 days before weaning with a 10 mg injection of progesterone on the da...
متن کاملresponse of lactating karakul ewes to two levels of exogenous estradiol 17.B along with progesterone and pregnant mare serum for induction of fertile estrus at early postpartum
متن کامل
Effect of weaning age on hair sheep lamb and ewe production traits in an accelerated lambing system in the tropics.
This study was designed to evaluate the impact of weaning age on lamb and ewe productivity in an accelerated lambing system. St. Croix White (STX) and Dorper × St. Croix White (DRPX) lambs were assigned at birth based on breed, gender, and litter size to be weaned at 63 (Early-1; 106 lambs and 68 ewes) or 90 d of age (Late-1; 99 lambs and 60 ewes) in Exp.1 or at 63 (Early-2; 77 lambs and 57 ewe...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of animal science
دوره 45 2 شماره
صفحات -
تاریخ انتشار 1977