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...

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...

BACKGROUND Perinatal mortality is a major cause of loss in the sheep industry. Our aim was to explore time trends in crude population stillbirth and neonatal mortality rates in Norway. We used data on 6,435,715 lambs from flocks enrolled in the Norwegian Sheep Recording System (NSRS) from 2000 through 2010 for descriptive analysis of trends. Longitudinal patterns of mortality rates were compare...

Considering the fact that sheep production has an important role in agriculture of Serbia, lamb performance is essential. Objective study was to investigate effect year, lambing season, sex and birth type on growth performances lambs MIS breed. Animal data (birth date, type, sex, weight -BW0, body after 30 days - BW30 60 ? BW60) are gained from control productive parameters maintained 2011 2020...

The aim of this study was to evaluate the effect of gonadotropin treatment on the in vitro maturation, blastocyst production, and developmental potential to term of oocytes collected from Sardinian neonatal and prepubertal ewes at 4 to 6 wk of age. Cumulus-oocyte complexes were recovered at 24 h after withdrawal of a 1/6th size progestagenated pessary from the donors, of which each received 120...