Performance records for 223 boars and gilts in Duroc and Yorkshire selected and control lines and for 231 boar and gilt progeny from reciprocal breed crosses were analyzed to evaluate (1) maternal effects, (2) effects of mass selection in purebreds on performance of crossbred progeny and (3) heterosis effects. Selection of purebred herd replacements was based mainly on an index (Index) of avera...

Sub-fertility is one of the most common problems observed in crossbred males, but the etiology remains unknown in most of the cases. Although proteomic differences in the spermatozoa and seminal plasma between breeds have been investigated, the possible differences at the sperm precursor cells and supporting/nourishing cells have not been studied. The present study reports the differential prot...

Two component traits of litter size of pigs, ovulation rate and embryonic survival, were examined in Meishan and composite white crossbred gilts and sows. At puberty, an ovulation rate of 12.5 was similar for Meishan (118 +/- 3 d of age) and crossbred gilts (217 +/- 3 d of age). The number of corpora lutea (CL) increased (4.3 CL) markedly (P < .01) from puberty to the sixth estrous period (220 ...

Sixty entire male pigs from 2 distinct genotypes (30 Alentejano purebred, an autochthonous fatty genotype, and 30 commercial crossbred pigs, a lean genotype) were used to investigate the effects of dietary CP reduction and low-Lys levels on growth performance, carcass traits, and meat quality. Pigs with 59.9 ± 2.0 kg BW were randomly assigned within each genotype to 1 of 3 diets [normal CP diet...

Effects of ractopamine hydrochloride (RAC) supplementation on growth performance and carcass characteristics of feedlot steers differing in biological type were investigated using British, Continental crossbred, and Brahman crossbred calf-fed steers (n = 420). Steers of each type were weighed at reimplantation [British, mean BW = 375 kg (SD = 38 kg); Continental crossbred, mean BW = 379 kg (SD ...

The use of terminal sires (TS) for crossbreeding is integral to the UK sheep industry where approximately 71% of market lambs are sired by TS rams. Early growth of these crossbred lambs affects profitability. The objectives of this study were i) to evaluate the effectiveness of index selection among TS on BW and ADG of their crossbred offspring; and ii) to compare the efficacy of that selection...

Growth performance, body composition, body conformation and meat quality were evaluated in crossbred pigs originating from three sire lines selected for leanness and conformation. The crossbred P, which was based on Belgian Piétrain had a leaner carcass and a better ham conformation compared to the other crossbreds. The presence of the halothane gene resulted in poorer meat quality in compariso...

A total of 399 crossbred ewes born in 2 yr were maintained either on irrigated or dryland hill pastures. The ewes were sired by North Country Cheviot, Dorset, Finnsheep or Romney rams mated to Suffolk or Columbia-type ewes. The crossbred ewes were mated to Hampshire rams throughout the study and had the opportunity for either 4 or 5 yr of production. Annual feed cost was calculated based upon e...