N. M. de Oliveira

Heritability of scrotal circumference in Corriedale rams

Abstract Measurements of scrotal circumference were recorded for 1154 ram Corriedale lambs at ten studs. The best estimate was 0.50±0.11 cm, which concurs with reports on other breeds. Due to this value and the importance of scrotal circumference on reproductive aspects, its employment has been suggested as an additional criterion in sheep selection plans.

Meat production in lambs of five breeds. Carcass and tissue composition.

The work was carried out at the Centro de Pesquisa de Pecuaria dos Campos Sulbrasileiros - CPPSUL/EMBRAPA, Bage, RS, Brazil, (field experiment) and at the Departamento de Zootecnia da Universidade Federal de Pelotas - UFPEL, Pelotas, RS, Brazil, (laboratorial fase) during 1994/95. Male lambs from Texel, Romney Marsh, Corriedale, Polwarth and Merino breeds (10 lambs per breed), born and raised on native pasture (mainly of Paspalum notatum Flugge and Axonopus affinis Chase), were weaned at 10 weeks of age, after what were fed with 200g/lamb/day of a concentrate containing 17% of crude protein and 75% of dry matter basis. Carcass weight and fat content, as well as carcass regional composition (weight of its main pieces) and leg and shoulder tissue composition (% of bone, muscle and fat), were examined. The results showed that, with exception of rib weight and shoulder fat content, breed differences were significant (P 0.05). Merino lambs had higher % of shoulder and lower % of leg (P 0.05) for % of rib. Carcasses from Romney, Corriedale and Merino lambs presented lower fat content scores. Both the Texel and Polwarth breeds had lower % of bone in the leg, however, the former was greater in muscle percentage with lower fat content. Marked breed differences were found in the shoulder tissue composition. Texel lambs were lower in °/o of bone and higher in % of muscle (P 0.0 5) for these components. There were no differences (P>0.05) regarding fat content in the shoulder.The work was carried out at the Centro de Pesquisa de Pecuaria dos Campos Sulbrasileiros - CPPSUL/EMBRAPA, Bage, RS, Brazil, (field experiment) and at the Departamento de Zootecnia da Universidade Federal de Pelotas - UFPEL, Pelotas, RS, Brazil, (laboratorial fase) during 1994/95. Male lambs from Texel, Romney Marsh, Corriedale, Polwarth and Merino breeds (10 lambs per breed), born and raised on native pasture (mainly of Paspalum notatum Flugge and Axonopus affinis Chase), were weaned at 10 weeks of age, after what were fed with 200g/lamb/day of a concentrate containing 17% of crude protein and 75% of dry matter basis. Carcass weight and fat content, as well as carcass regional composition (weight of its main pieces) and leg and shoulder tissue composition (% of bone, muscle and fat), were examined. The results showed that, with exception of rib weight and shoulder fat content, breed differences were significant (P 0.05). Merino lambs had higher % of shoulder and lower % of leg (P 0.05) for % of rib. Carcasses from Romney, Corriedale and Merino lambs presented lower fat content scores. Both the Texel and Polwarth breeds had lower % of bone in the leg, however, the former was greater in muscle percentage with lower fat content. Marked breed differences were found in the shoulder tissue composition. Texel lambs were lower in °/o of bone and higher in % of muscle (P 0.0 5) for these components. There were no differences (P>0.05) regarding fat content in the shoulder.

Meat production of lambs of five breed types. 1. Growth and development.

The work was carried out at the Centro de Pesquisa de Pecuaria dos Campos Sulbrasileiros (CPPSUL) of EMBRAPA, Bage, RS, during 1994/95 with male lambs of the Texel, Romney Marsh, Corriedale, Polwarth and Merino breeds, bom and raised up to weaning (10 weeks) on native pasture (mainly composed by de Paspalum notatum Flugge e Axonopus affinis Chase). Growth and development up to slaughtering at 7.5 months were evaluated. After weaning, besides the native pasture, all lambs (10 per breed) werefed with a concentrate containing 17% of crude protein and 75% of dry matter basis (200 g/lamb/day), until the slaughtering age. The results showed that birth weight of breeds was similar (P>0.05); however, the liveweight at weaning and the liveweights after weaning of both Texel and Romney Marsh lambs were greater than those of Corriedale, Polwart and Merino lambs. They showed liveweights always similar. The first fourty five days after weaning, lambs of Texel, Romney Marsh and Polwarth breeds showed greater food conversion. In all genotypes, liveweight gains after 5.5 months of age had no importam contribution (in relation to time) to the slaughtering weight.

Meat production of lambs of five breed types. 2. Live weight components.

Fifty (ten per breed) Merino, Polwarth, Corriedale, Romney Marsh and Texel lambs were castrated at 30 days of age and raised up to weaning (ten weeks) on native pasture (mainly composed by Paspalum notatum Flugge and Axonoplus qffinis Chase) in the Southern (Bage, RS) region of Brazil. Following weaning, the animals were feedloted during one week and each lamb was daily fed 200 grams of a diet containing 17% of crude protein and 75% of dry matter basin. The animals were then moved to pasture up to 225 days of age when they were slaughtered to compare their live weight as a total and its components. Live weight was influenced by genotypes. This effect might not be observed in absolute numbers, but in percentage (head), or vice-versa, as shown by heart, lungs and liver. The Texel breed showed higher absolute values as compared to Merino. Polwarth, Corriedale and Romney Marsh. Percentualy, this superiority was only observed in carcass. Merino and Polwarth showed higher skin percentage, as compared to other breeds.Fifty (ten per breed) Merino, Polwarth, Corriedale, Romney Marsh and Texel lambs were castrated at 30 days of age and raised up to weaning (ten weeks) on native pasture (mainly composed by Paspalum notatum Flugge and Axonoplus qffinis Chase) in the Southern (Bage, RS) region of Brazil. Following weaning, the animals were feedloted during one week and each lamb was daily fed 200 grams of a diet containing 17% of crude protein and 75% of dry matter basin. The animals were then moved to pasture up to 225 days of age when they were slaughtered to compare their live weight as a total and its components. Live weight was influenced by genotypes. This effect might not be observed in absolute numbers, but in percentage (head), or vice-versa, as shown by heart, lungs and liver. The Texel breed showed higher absolute values as compared to Merino. Polwarth, Corriedale and Romney Marsh. Percentualy, this superiority was only observed in carcass. Merino and Polwarth showed higher skin percentage, as compared to other breeds.