These studies test the hypothesis that the increased adrenocorticotropic hormone (ACTH) and cortisol in pregnancy reflect a reset of regulated plasma cortisol concentrations. Ewes were sham operated (Sham) or adrenalectomized (ADX) at ∼108 days gestation. Adrenalectomized ewes were replaced with aldosterone (3 μg ⋅ kg-1 ⋅ day-1) and with cortisol at either of two doses (ADX + 0.6 and ADX + 1.0 ...

By using continuous infusions of 3H- and 14C-labelled substrates, three-pool models, incorporating rumen propionate, plasma glucose and blood carbon dioxide were constructed to determine the contribution of propionate to glucose in non-pregnant, pregnant (mid and late) and lactating hill ewes. Although the intakes of non-pregnant and pregnant ewes were the same (1200 g dried grass/d) and result...

In order to study the effects of sheep teat disorders on the protection of the mammary gland, we used a Mannheimia haemolytica isolate, which did not cause clinical mastitis when deposited into intact teats. In the first experiment, this was deposited into the duct of teats with orf (Group A, n=5) or papilloma (Group B, n=3). In the second, teats were chapped and then, the organism was deposite...

The behaviour was similar in the ewes of the two breeds. When rams were introduced among ewes in the late summer and autumn, mating always commenced immediately, and most ewes mated within the first three to four weeks. On some occasions when rams were introduced in the spring, there was a delay before mating began; on most other occasions the initial rate of mating was rather low and in most i...

Range ewes are commonly evaluated for milking ability by producers to determine the ewe's ability to rear lamb(s). The U.S. Sheep Experiment Station has subjectively scored (low, average, high) a ewe's milking ability within 24 h of lambing for many years. The relationship of subjective milk scores with lamb production was investigated using lambing records of Columbia (n = 1,731), Polypay (n =...

St. Croix White and Barbados Blackbelly hair sheep ewes were used to evaluate the effect of supplemental nutrition around lambing on ewe and lamb performance during the wet season on St. Croix. Beginning 14 d prior to expected day of lambing (day 0) and for 21 d postpartum, 11 ewes were fed a pelleted complete ration (17% crude protein) at a level to provide 150% of the nutrient requirements, i...

To determine similarities and differences between nonsuperovulated and superovulated ewe models, data collected from several experiments (1989 through 2005) were analyzed. Mature non-pregnant non-superovulated (n = 91) or superovulated (n = 299) Western range-type ewes were used for evaluation of luteal function. To induce superovulation, ewes were injected twice daily with FSH on days 13 to 15...

A new mutation in the bone morphogenetic protein 15 (BMP15) gene (FecX allele) causing increased prolificacy in heterozygous (R+) and sterility in homozygous ewes has been recently described in Rasa Aragonesa, a low-prolificacy Mediterranean breed. The current study determined, first, the effect of this polymorphism on natural and eCG-induced ovulation rate (OR) and the effect of eCG dose on re...

introduction as pregnancy progresses, nutrient requirements of fetus and thereby ewe increases and some changes in the levels of blood metabolites including glucose, cholesterol and total protein may occur. during gestation, maternal tissues contribute to supplying energy that required for fetus resulting in changes of ewe blood metabolites; however other factors such as breed, age, feeding typ...

background:chronic active adrenocorticotropin hormone (acth) immunization of ewes (with a previous history of immunization) resulted in elevated titres of antibody against acth, which induced a reduction in circulating levels of cortisol. objectives:the aim of the present study was to investigate: a) the influence of active immunization against acth on milk production of the ewe as assessed by ...