Influence of management system on litter size, lamb growth, and carcass characteristics in sheep.

Abstract

Three management systems (winter, spring, and late summer) distinguished by season of lambing and management practices were compared for litter size born and weaned and growth and carcass characteristics of lambs. Three sire breeds (Cheviot, Rambouillet, and Suffolk) and three dam breeds (Florida Native, Native-X, and Synthetic-X) were used in 698 matings over a 3-yr period. System affected (P < .01) litter size born. Spring lambing yielded more lambs (1.62) than winter (1.49) and late summer (1.12). The winter-born lambs were lighter but fatter (P < .05), and spring-born lambs were leaner with higher leg conformation and carcass quality scores. The late summer-born lambs were not different from spring-born lambs. Wethers had higher (P < .01) weights off test than ewe lambs (43.9 vs 42 kg) but had lower (P < .01) leg conformation scores, percentage kidney and pelvic fat, yield grade, and dressing percentages. Dam breed effects were significant (P < .05) for average preweaning daily gains with 249+/-5, 201+/-9, and 191+/-9 g for progeny of Native-X, Florida Native, and Synthetic-X, respectively. Single-born lambs had higher daily gains (P < .05) than twins in a preweaning period in all management systems and higher postweaning and lifetime daily gains for winter and spring management systems.

Improving performance of Zackel sheep through cross-breeding with prolific Bluefaced Leicester under semi-intensive and extensive production systems

“…Also, a cause of the lack of effect of production system was that lambs from the extensive system (Site 2) were born during early spring (late MarchÁ April) and had access to pasture and warmer weather, compared with lambs from the semi-intensive system (Site 1) that were born mainly during February, late winter. The results are in accordance with those presented by Dimsoski et al (1999), who reported differences for finishing body weights in spring-vs. winter-born lambs.…”

Características de carcaça de cordeiros Hampshire Down e Santa Inês sob diferentes fotoperíodos

“…Vários fatores afetam o peso e o rendimento de carcaça, entre eles alimentação, sexo, sistema de produção, peso ao abate, idade e raça (Lee et al, 1990;Osorio et al, 1996;Hopkins & Fogarty, 1998;Hopkins et al, 1998;Dimsoski et al, 1999;Moron Fuenmayor & Clavero, 1999). As diferenças são facilmente observadas quando o peso e a idade diferem no período de abate.…”

“…Apesar da prática do confinamento elevar os custos e aumentar a mão-deobra, em algumas situações é extremamente vantajosa (Notter et al, 1991;Dimsoski et al, 1999). Em determinados estados do Brasil, entre os quais São Paulo e Paraná, o confinamento de cordeiros tem sido adotado com freqüência.…”

The effects of diet, slaughter weight and docking on growth, carcass composition and meat quality of fat-tailed Barbarine lambs. A review

“…Increased fat deposition in FL fed animals compared to those on pasture has been reported by several authors (Borton et al 2005;Nuernberg et al 2005 and 2008) on TT breeds. Dimsoski et al (1999) showed on TT lambs that pasture-fed lambs were heavier than concentrate-fed lambs, but they had less back fat and percentage of kidney and pelvic fat. The intake of energy exceeded the requirements for growth and maintenance, which shifted metabolism to fat production at younger ages (Dimsoski et al 1999).…”

“…Dimsoski et al (1999) showed on TT lambs that pasture-fed lambs were heavier than concentrate-fed lambs, but they had less back fat and percentage of kidney and pelvic fat. The intake of energy exceeded the requirements for growth and maintenance, which shifted metabolism to fat production at younger ages (Dimsoski et al 1999). However, Jones et al (1984) reported no difference in carcass characteristics between concentrateand pasture-fed lambs, when adjusted for subcutaneous fat.…”