Effects of Dorset, Finnsheep, Romanov, Texel, and Montadale breeds for performance as sires were estimated in the initial phase of a comprehensive evaluation of these breeds as contributors to sheep crossbreeding systems. Objectives were to evaluate the effects of ram breed, ewe breed, season of mating, and two-way interactions. Rams from the five breeds were single-sire-mated with ewes from tw...

Objectives were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), dam breed (Composite III and northwestern whiteface), mating season (August, October, and December), ewe age (1, 2, and 3 yr), and their interactions on reproductive traits of F1 ewes. A total of 1,799 F1 ewes produced 3,849 litters from 4,804 exposures to Suffolk rams during 35-d mating season...

Objectives were to estimate effects of sire breed (Dorset, Finnsheep, Romanov, Texel, and Montadale), dam breed (Composite III and northwestern whiteface), mating season (August, October, and December), ewe age (1, 2, and 3 yr), and their interactions on reproductive traits of F1 ewes. A total of 1,799 F1 ewes produced 3,849 litters from 4,804 exposures to Suffolk rams during 35-d mating season...

Lamb's birth weight and litter weight were found to be related to ewe weight. Deviations from generally applicable formulae indicated an interaction between the genotype of the lamb and the maternal environment, as suggested in egg transfer experiments. Land's (1977) hypothesis on the spare conceptus capacity, when comparing large and small breeds within a species, with respect to prolificacy, ...

O NE hundred seventy-nine ewe lambs from a three-breed polyallel cross involving the Willamette, Suffolk and Hampshire breeds were used to study the genetic aspects of fertility. Ewe birth weight, ewe weight at mating and fertility were analyzed in relation to heterosis, general combining ability, maternal effect, reciprocal differences, and the effects of a hormone treatment. Treatment consist...

East Friesian-sired F1 ewe lambs (n = 27) and Lacaune-sired F1 ewe lambs (n = 31) born in 1999 were compared for lamb production, lactation performance, and udder morphology traits in a dairy sheep production environment in 2000. The ewe lambs were the progeny of seven East Friesian and five Lacaune sires. A contemporary group of high percentage East Friesian ewe lambs (> 3/4 East Friesian, n =...

knowledge on animal requirement, available forage and its quality is fundamental for successful livestock and range management. since sheep is dominant grazing animal of rangelands in iran and there are over 27 sheep breeds and each breed has special body size, physiological condition and consequently different daily nutrition requirement, animal unit should be determinated for dominant breed o...

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 × ...

78 Ghezel and 76 Mehraban sheep were used to evaluate the effect of fat-tail docking on reproductive performance. Within two days after birth the tails of 32 Ghezel female lambs and 28 Mehraban female lambs were docked using a tight rubber ring. The lambs were allowed to reproduce for three lambing opportunities and their reproductive performances were evaluated. The effect of docking on the fe...

Birth and weaning weights were studied for purebred Finnsheep, Suffolk, Targhee and Minnesota 100; F1 Finnsheep crosses; F2: and standard breed and Finnsheep backcrosses. Finnsheep lambs were the smallest of all lambs at birth, but ranked second among purebreds in 70-day weaning weight (Suffolks, 21.0 kg vs Finnsheep, 17.6 kg). Ewe body weight, grease fleece production and total adjusted weight...