A resource population of ewes derived from Dorset and Romanov grandparents was generated over 5 yr to provide genotypic and phenotypic data to estimate effects of each callipyge genotype on component traits of reproduction. Effects on ovulation rate were estimated from data recorded by examination of ovaries from serially slaughtered ewe lambs (n = 174) born in 1994 and 1995. Productivity and l...

The Rafter 7 Merino flock was initiated in Nevada in 1990 with the purchase of 500 purebred Rambouillet ewes. A gradeup program was initiated using Australian Merino genetics with the aim of developing a purebred Merino flock. Early in the project the Rafter 7 Merino line was created, which is approximately 5/8 Merino and 3/8 Rambouillet and has been a closed line since 1999. In a genetic selec...

Forty two Malpura lambs (21 d old) were divided into three groups of 14 each consisting of 8 females and 6 males. Lambs were allowed to suckle their respective dams twice daily up to weaning (13 wks) and offered free choice concentrate and roughage in a cafeteria system. The lambs in control group were fed conventional concentrate mixture, in RBO group concentrate mixture fortified with 4% indu...

Forty male Omani lambs were used in a feeding trial to study the effects of feeding diets containing various levels of metabolizable energy (ME) on growth and carcass composition. Ten lambs were selected randomly and slaughtered at the start of the trial to provide information on initial carcass composition. Thirty lambs were divided randomly into three groups and fed three diets varying in ME ...

BACKGROUND Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs. METHODS Ewes on four organic farms were allocated five or si...

Research in the area of fetal programming has focused on intrauterine growth restriction. Few studies have attempted to examine programming mechanisms that ultimately lead to lambs with a greater potential for postnatal growth. We previously demonstrated that treatment of ewes with GH at the time of breeding led to an increase in birth weight. Therefore, the objective of this study was to deter...

Two trials examined genetic and environmental influences on muscle fiber type proportions. Trial 1 compared Polypay and Coopworth x Polypay male lambs either left intact or castrated early, mid or late in growth. Trial 2 compared Hampshire-sired lambs (females, early castrate wethers and late castrate wethers) from Suffolk x Coopworth dams and whiteface x Coopworth dams. Half the lambs in each ...

This study aimed to analyze the economic feasibility of replacing soybean meal by sunflower cake in the diet of lambs. Twenty-eight non-castrated crossbred Suffolk lambs aged four months, with 21 kg average body weight ± 9 kg were used. These animals were distributed by weight category into 3 treatments (10, 20 and 30% dry matter (DM) addition of sunflower cake in replacing soybean meal) and co...

The sheep sector has not suffered the technification that other livestock sectors have. lack of technological knowledge farmers and economic limitations have made this difficult. One most widely used technologies is Precision Livestock Farming (PLF). PLF already been in to improve farming efficiency. In light problem weighing lambs their low precision, paper proposes a system for estimating wei...

A large sheep dataset including ewe and progeny records from 1982 through to 2006 was used in the present study. The data included the variables: sex of lamb, birth rank, weaning weight, year born and dam and sire. The aim was to firstly, determine if the age of the ewe’s dam, or the birth rank of the ewe affected her lifetime performance and secondly, to determine in twin-born lambs if the sex...