Consumo, desempenho e análise econômica da alimentação de cordeiros terminados em confinamento com o uso de dietas de alto grão [Consumption, performance and RESUMOO presente experimento, conduzido no Laboratório de Ovinocultura da Universidade Federal de Santa Maria, teve como objetivo avaliar o efeito do uso de diferentes dietas de alto grão sobre o consumo de nutrientes e o desempenho de cordeiros terminados em confinamento, bem como realizar uma análise econômica da alimentação utilizada para terminação dos animais. Foram utilizados 32 cordeiros machos, castrados, da raça Texel, nascidos de parto simples e desmamados com aproximadamente 50 dias de idade. Os tratamentos foram constituídos por diferentes tipos de grãos, não processados, sendo: grão de milho, grão de aveia branca, grão de aveia preta ou grão de arroz com casca. Os animais foram abatidos quando atingiram o peso vivo de abate pré-estabelecido de 32kg, que corresponde a 60% do peso adulto de suas mães. Cordeiros alimentados com dietas de alto grão de milho apresentam maiores consumos de matéria seca, matéria orgânica, proteína bruta, carboidratos totais e de nutrientes digestíveis totais, menor consumo de fibra em detergente neutro, melhor escore de condição corporal, ganho de peso e conversão alimentar, o que leva à redução do número de dias no confinamento necessários para atingir o peso de abate. Além disso, cordeiros terminados com o uso de dieta de alto grão à base de grão de milho proporcionam melhor resultado econômico quando comparados com cordeiros terminados com as demais dietas de alto grão utilizadas neste experimento. O uso de dietas de alto grão de milho, aveia branca, aveia preta ou arroz com casca para terminação de cordeiros em sistema de confinamento é uma alternativa viável do ponto de vista produtivo. Porém, o uso de grão de milho proporciona melhores resultados produtivos e econômicos.Palavras-chave: conversão alimentar, ganho de peso, ovinos, Texel ABSTRACT

Sheep production on pasture plays an important role in subtropical climates around the world, with great economic and environmental relevance to those regions. However, this production is much lower than its true potential in subtropical regions, largely due to lack of knowledge of how to feed grazing lambs, and mitigate gastrointestinal parasite infections. Due to weather instability and the high growth rate of tropical grasses, it is difficult to adjust the quality and quantity of feed consumed by lambs. In addition, due to warm, wet weather during spring, summer, and autumn, gastrointestinal parasite infection can be intense on subtropical pastures. Thus, the objective of this paper is to summarize 17 years of research in southern regions of Brazil testing alternative management for sheep farmers under these challenging conditions. Our review indicates that ewes play important roles raising their lambs. Besides protecting and providing milk, they leave a better pasture structure for lamb nutrition. The use of creep feeding and creep grazing are additional alternatives to improve lamb growth. However, feeding supplementation with concentrate can deteriorate pasture quality at the end of the summer–autumn season. Gastrointestinal parasitic infections can be reduced with improved lamb nutrition, although L3 larvae of Haemonchus contortus can be present at various pasture heights. This indicates that it is difficult to control L3 ingestion solely by manipulating grazing heights. We summarize important technologies for raising lambs on pasture-based systems to make the best of high herbage growth and minimize intense parasitic infections common in subtropical regions. We discuss research results in light of the latest studies from other ecoregions and climates, although there is a lack of similar research in subtropical regions of the world.

BackgroundThe use of agroindustrial by-products in ruminant nutrition to be an interesting alternative in order to reduce production costs and environmental impacts arising from the inadequate destination of residues. The initial step of beer production yields a large volume of wet brewer’s grains all year around, which is available at a low cost and has a high nutritional quality, and hence a big potential for animal production.MethodsTwenty-four Suffolk non-castrated male lambs, from simple parturition were kept in individual spots and allocated to four treatments constituted by four levels of substitution of sorghum silage by WBG (i.e.0; 33.5; 66.5 and 100% of substitution). It was used roughage: concentrate rate of 50:50, based on dry matter.ResultsThe ether extract intake increased while the acid detergent fiber intake decreased linearly (P ≤ 0.05). Substituion of sorghum silage by WBG did not change lambs’ feed DMI, daily weight gain and feed conversion.ConclusionThe substitution of sorghum silage by WBG as roughage showed to be a viable alternative from the productive and economic point of view for finishing of feedlot lambs.

Consumo e desempenho de cordeiros e borregos alimentados com dietas de (% of LW and g/kg LW 0.75 ), CPI (kg/day, % of LW and g/kg LW 0.75 ), EEI (% of LW), NDFI and ADFI (% of LW and g/kg LW 0.75

This study aimed to evaluate the effect of using different high-grain diets on the carcass characteristics and tissue composition of the meat of feedlot-finished lambs. Thirty-two male castrated Texel lambs born from single births and weaned at approximately 50 days of age were allotted to treatments that consisted of different unprocessed grains, as follows: corn grain, white oat grain, black oat grain, or grain of rice in the husk. The animals were slaughtered upon reaching the pre-established slaughter weight of 32 kg, which corresponds to 60% of the mature weight of their mothers. Lambs fed the high-corn grain diet had higher weights and yields of hot and cold carcass and larger loin-eye areas than those finished in the feedlot receiving high-grain diets based on white oat, black oat, or rice in the husk. Additionally, they had a higher degree of fatness and a thicker subcutaneous fat layer at slaughter, which lead to decreased cooler shrink loss. The neck, shoulder, ribs, and leg cuts were heavier in lambs fed the high-corn grain diet. By contrast, these lambs had a lower proportion of leg, more rib, and higher meat fat content, which may be undesirable for the consumer market. The use of high-corn grain diets, in comparison with high-grain diets based on black oat, white oat, and rice in the husk, may be recommended for finishing lambs in the feedlot when they are slaughtered at similar weights.

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The aim of this study was to assess the influence of different finishing systems on the in vivo measurements, quantitative and qualitative carcass characteristics, commercial cut ratio, and shoulder tissue composition of lambs. Thirty-two male lambs were distributed in four finishing systems with eight replications each, as follows: suckling lambs on pasture; suckling lambs in confinement, with access to creep-feeding containing corn bran and soybean meal; weaned lambs fed roughage, characterized by ad libitum supply of alfalfa hay; and weaned lambs fed concentrate, composed of oat grain and soybean meal. The lambs were slaughtered as they reached the pre-set live weight at slaughtering of 30 kg. Most of the in vivo biometry variables were not significant (P > 0.05) when comparing the finishing systems, except for hindlimb height and thoracic perimeter. Regarding the quantitative carcass characteristics, all variables differed (P < 0.05) between systems, except for carcass length, leg width, and subcutaneous fat thickness. For the qualitative carcass characteristics, only the fatness and carcass conformation presented significant differences (P < 0.05). Most in vivo measurements and the proportion of carcass cuts were not influenced by finishing systems. Weaned lambs fed an exclusive concentrate diet presented leaner carcasses with an inferior conformation when compared to the other finishing systems. Suckling lambs in confinement presented shoulders with a higher fat deposition when compared to those weaned. Suckling lambs both on pasture and in confinement presented a superiority in the quantitative carcass characteristics when compared to weaned lambs.

It can be hypothesized that the body composition characteristics of different sheep breeds affect their nutritional requirements. However, no study has yet been carried out to determine the nutritional requirements for maintenance of Texel purebred lambs, despite their growing importance in sheep meat production globally. Our objective was therefore to determine the energy and protein requirements for maintenance of Texel lambs. Thirty-four Texel lambs were used, all intact males that were weaned at 50 days old, and confined in individual pens. Two experiments were conducted, as follows. In Experiment 1, a digestibility assay was performed to determine the dietary energy value, in a 3×3 double Latin square design, in which lambs were submitted to three levels of feed restriction (0%, 55% and 70% of ad libitum feed intake). In Experiment 2, the energy and protein requirements for maintenance of Texel lambs from 21 to 40 kg BW were determined using a randomized block design, in which lambs were also submitted to three levels of feed restriction (0%, 55% and 70% of ad libitum feed intake). The requirements for net energy for maintenance (NEm), metabolizable energy for maintenance (MEm), net protein for maintenance (NPm) and metabolizable protein for maintenance (MPm) were determined. The digestibility of dry matter, energy, protein and metabolizability were similar between food restriction levels, averaging 74.4%, 75.5%, 80.3% and 0.636, respectively. The NEm determined for growing Texel lambs was 263 kJ/kg of the metabolic fasting BW (FBW), the MEm was 417 kJ/kg0.75 FBW and the efficiency of use of MEm was 0.63. In addition, the NPm was 1.24 g/day per kg0.75 FBW and the MPm was 2.98 g/day per kg0.75 FBW. The energy requirements of Texel lambs are different from those reported in the literature, possibly due to differences between breeds, diets and environmental effects, whereas the protein requirements are different from literature mainly due to methodological differences; further studies are need to address these aspects that affects the nutritional requirements for raising sheep from different breeds in different environments.