Carcasses of Churro Galego Bragançano purebred and Suffolk and Merino Precoce crossbred lambs reared under three different conventional production system of northeast of Portugal were evaluated. Carcasses of male lambs had larger muscle longissimus width (P < 0.05) and smaller subcutaneous fat thickness (P < 0.05) than the female lambs. Carcasses of crossbred lambs had higher (P < 0.05) compact...

Two / 2 East Friesian (EF), one / 4 EF, one / 8 EF, and several Dorset rams were mated to crossbred ewes from 1993 through 1996. Growth, reproduction, and lactation performance of their progeny were compared. EF-cross lambs had greater birth, weaning, and postweaning weights than Dorset-cross lambs. When lambing at one and two years of age, EF-cross ewes gave birth to and reared more lambs per ...

Crossbred ewes (1/2 Dorset, 1/4 Rambouillet, and 1/4 Finnsheep) from a flock being selected for spring fertility, defined as ability to lamb following ram exposure in May and June in Virginia (37 degrees N latitude), were used to study the duration of the seasonal anestrus. In the first 3 yr of the study (1992, 1993, and 1995), mature ewes were divergently selected based on EBV for fertility, a...

The reproductive responses to one and two inseminations of fresh extended semen were compared in crossbred sheep housed in confinement. In three trials, ewes in progestogen-induced estrus were inseminated 54 to 56 h after sponge removal. Half the ewes received a second insemination 4 or 5 h later. Resultant fertility, litter size and embryonic mortality indicated no advantage to a double insemi...

a crossbreeding experiment involving four iranian fat-tailed sheep breeds, namely kurdi (k), chaal (c), afshari (a) and sanjabi (s) was carried out to determine the ram breed effects on productivity of kurdi fat-tailed ewes (k) under extensive production system. a total of 475 kurdi ewes were mated to 24 rams from four breeds producing 454 lambs including pure kurdi, kk, (116 lambs), afshari × ...

Lifetime (5 yr) lamb production and wool production from 207 straightbred Targhee (T) and 474 1/4 Finn-1/4 Dorset-1/2 Targhee (FDT) crossbred ewes managed in a range or farm flock system were evaluated for ewe fertility, prolificacy, ewe fleece weight, and total lamb weight weaned per ewe exposed. Data included 2,620 ewe exposures, 2,384 parturitions, 4,638 lambs born, and 3,498 lambs weaned. E...

Variation in ovulation rate of ewes was studied with particular reference to the heterosis effect in a 3-breed (Dorset Horn, South Australian Merino, Corriedale) experimental sheep population. For the population as a whole, heterosis effect on the young (1 1/2 year-old) ewes (+0.17 k 0.06** ova, or 14.5%) was similar to that on the mature (5 1/2 year-old) ewes (+0.19 f 0.06** ova, or 12.5%), in...

Image processing technique was used to compare udder morphological characteristics in two Iranian crossbred sheep populations including Ghezel-Arkhamerino, Moghani-Arkharmerino and a pure one that was Ghezel ewes. In addition, the resulted measurements were applied as independent variables for estimation of daily milk yield by regression models. Udder height of Ghezel was higher than Ghezel-Ark...

The response to melatonin expression is one way that circadian rhythms of many biological processes are regulated. To evaluate the relationship between the melatonin receptor 1A (MTNR1A) gene and reproductive performance, records were compared in Dorset and 3/4-Dorset x 1/4-East Friesian ewes expressing different genotypes at the MTNR1A gene in the Cornell University sheep flock. There were 116...

The objective of this experiment was to determine whether passive immunization against a synthetic inhibin-like peptide (alpha-IF) increases FSH secretion and reproductive performance of ewes bred in the spring. Crossbred ewes were assigned to three treatment groups of 10 ewes each. Progesterone-releasing pessaries (CIDR-G) were inserted and left in place for 12 d. The CIDR-G were removed on Ap...