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 × ...

Ewe productivity is synonymous with annual litter-weight weaned (LWW) per ewe exposed to rams for breeding, and LWW is largely a function of number of lambs born (NLB) and weaned (NLW). Selecting for LWW should increase litter size and numbers of ewe-ram co-twins. Thus, we used historical records to determine whether sex of co-twin affected lifetime productivity of twinborn ewes. United States ...

Late gestation supplementation of feed additives, such as rumen undegradable intake protein (RUIP), vitamin E, Zn, and chlortetracycline, has inconsistently improved ewe/lamb productivity. In 3 experiments, Western white-faced ewes were supplemented for at least 30 d during late gestation with 204 g/(ewe.d) on a DM basis of high (HS; 12.5% RUIP, 880 IU/kg of vitamin E, 176 mg/kg of Zn supplied ...

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...

early weanling and rearing of lambs on milk replacer is an important act to increasing flock productivity. two experiments were carried out to compare the voluntary intake and nutrients digestibility ewe milk and commercial milk replacer and their feeding effects on the growth rate, feed intake and feed efficiency of suckling lambs. in experiment 1, eight lambs (two 4-lamb groups) at 31 to 34 d...

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...

A 4-year interdisciplinary study was performed to compare two organically managed sheep production systems, using 118 ewes and 24 ha each. The systems differed in the ewes' reproduction rhythm: one lambing per ewe per year (1L/1Y), with the aim of balancing feed self-sufficiency and lamb marketing periods v. three lambings over 2 years (3L/2Y), with the aim of maximising ewes' productivity. The...

The present study was carried out to estimate (co)variance components and genetic parameters for some productivity traits of Baluchi ewes. The data were collected during a 31 year period (1984-2014) at the experimental breeding station of Baluchi sheep, which is located in north-east of Mashhad, Iran. The analysis was based on 14030 records of lambs and 4371 records of ewes. Investigated traits...

Data of 3272 lambing records collected on 818 ewes born from 689 dams and sired by 371 rams were used in the evaluation of ewe lifetime productivity (total number born, number weaned and total weight weaned). These records were collected from ewes born from 1969 to 1994 and which gave birth during the period from 1971 to 1999. Year of birth of ewe and ewe two-tooth liveweight affected the ewe p...