Context Mating of ewe lambs can increase farm profitability, although uptake is limited by low reproductive success. Reproductive loss to Day 35 pregnancy in peripubertal greater than adult ewes; however, the precise timing this unknown.Aim We aimed define more clearly early embryo development and key times ewes.Methods Health embryos from naturally cycling crossbred ewes ~8months age were reco...

Female reproductive trait were studied in four pure breeds (the Finnsheep, Suffolk, Targhee and Minnesota 100), the F1 crosses between Finnsheep rams and females of the other three breeds and F2 and backcross ewes. Precocity of sexual development, defined as the percentage of ewe lambs lambing at 12 months of age, was measured in 709 ewe lambs in 4 years. Lambing and weaning rates were measured...

Relevance. The article provides a justification for the use of sheep selection taking into account intra-breed type Prekos ewes in purebred breeding and crossing with producers semi-fine wool breeds Romney-Marsh Kuibyshevskaya to improve biological usefulness meat offspring. Methods : scientific economic experiment different options, productive Precos breed. Results. presents results study on i...

Administration of exogenous melatonin (MEL) and progesterone (P4) in conjunction with follicle stimulating hormone (FSH) affects the number of developing follicles and oocyte quality in the anestrus ewe. Crossbred Rambioullet x Targhee Western range ewes (n=25) were randomly assigned to four treatment groups in a 2 x 2 factorial design [+/-MEL and +/CIDR device; MEL/CIDR, CIDR, MEL, and Control...

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...

In a recent study from our laboratory, a combination of melatonin implants and controlled internal drug release devices increased the number of developing follicles in follicle stimulating hormone-treated anestrous ewes; however, CIDR treatment decreased the rate of in vitro fertilization (IVF). In the current study, effects of alternative CIDR treatments on follicular development and rate of I...

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...

Genetic parameters of longevity in crossbred Mule ewes, and genetic relationships among longevity, growth, body composition, and subjectively assessed traits on Mule lambs and ewes have been estimated using Bayesian linear censored models. Additionally, the genetic associations between longevity and culling reasons were examined. Data comprised 1,797 observations of Mule ewes for longevity, cul...

The study involved 120 crossbred ewes (sixty 1.5 years old animals and sixty 2.5 years old animals; initial liveweight 67.6 kg, condition score 3.7), that were mated in October. They were assigned to six treatments (two shearing treatments (shorn and unshorn) × two silage feed values (low and medium) and two extended grazed herbage allowances (1.0 and 1.8 kg dry matter (DM)/day)) designed to ev...

This study investigated the effects of different planes of nutrition in early pregnancy (EP) and mid-pregnancy (MP) of crossbred ewes on carcass characteristics of male offspring and reproductive performance of female offspring. During EP (d 1 to 39 after synchronized mating) ewes were allocated 60% (low, L-EP), 100% (medium, M-EP), or 200% (high, H-EP) of their energy requirements for maintena...