Supplementation of grazing suckling beef calves receiving different energy sources

Abstract

The aim of this study was to evaluate the effect of different energy sources -corn, sorghum, and wheat bran -on performance, intake, digestibility, and nitrogen utilization efficiency of beef calves subjected to creep feeding. Thirty-four calves (12 males and 22 females) with initial age and weight of four months and 108±3.9 kg, respectively, were used in a randomized-block experimental design with four treatments and two blocks (males and females). Treatments were control (MM), a mineral mixture ad libitum; corn (C); corn + sorghum (C+S); and corn + sorghum + wheat bran (C+S+WB). Supplements contained approximately 20% crude protein (CP), and were fed in the amount of 0.5% of body weight. Supplemented animals had higher performance (P<0.05) when compared with those on treatment MM. Supplementation increased (P<0.05) the intakes of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber corrected for ash and protein (NDFap), non-fibrous carbohydrates (NFC), digestible neutral detergent fiber (dNDF), and digestible organic matter (dOM). The digestibility of NFC was higher (P<0.05) in the supplemented treatments. The C+S and C+S+WB treatments provided increased digestibility (P<0.05) of OM, CP, and NDFap. The synthesis of nitrogen compounds was higher (P<0.05) in animals on treatment C as compared with those on the other supplemented treatments. Animals on treatments C+S and C+S+WB had higher (P<0.05) nitrogen utilization efficiency compared with those on the other treatments. Concentrate supplementation improved the animal performance. The use of other energy sources (sorghum or wheat bran) in association with corn is recommended for suckling calves. ResumoO objetivo deste trabalho foi avaliar o efeito de diferentes fontes energéticas, milho, sorgo e farelo de trigo, sobre o desempenho, o consumo, a digestibilidade aparente total dos constituintes da dieta e a eficiência de utilização dos compostos nitrogenados em bezerros de corte submetidos ao creep feeding. Foram utilizados 34 bezerros lactentes (12 machos e 22 fêmeas) com idade e peso médio inicial de quatro meses e 108±3,9 kg, respectivamente. O experimento foi conduzido em blocos casualizados com quatro tratamentos e dois blocos (machos e fêmeas). Os tratamentos foram: controle (MM), fornecimento de mistura mineral ad libitum aos animais; milho (M); milho + sorgo (M+S) e milho + sorgo + farelo de trigo (M+S+FT). Os suplementos continham aproximadamente 20% de proteína bruta (PB) e foram fornecidos na quantidade de 5 g kg -1 do peso corporal. Os animais suplementados apresentaram maior (P<0,05) ganho de peso quando comparados com os animais do tratamento MM. A suplementação aumentou (P<0,05) os consumos de matéria seca (MS), matéria orgânica (MO), PB, fibra em detergente neutro corrigida para cinzas e proteína (FDNcp), carboidrato não fibroso (CNF), fibra em detergente neutro digerida (FDNd) e matéria orgânica digerida (MOD). A digestibilidade aparente total do CNF foi maior (P<0,05) nos animais suplementados. Os tratamento...

Supplementation levels for suckling female calves under grazing: productive and nutritional performance and metabolic profile

“…Therefore, they both was slightly higher than suggested by abovementioned authors to maximize forage intake by grazing cattle and the nitrogen utilization efficiency, showing a slightly unbalanced dietary protein-to-energy ratio when adequacy of intake is considered, which seems to support the similar forage intake among treatments (Table 4). A similar pattern was reported by Marquez et al (2014) and Lima et al (2016) when supplemented suckling calves in the tropics.…”