Cottonseed for protein and energy supplementation of high-roughage diets for beef cattle

Nutritional diversity of agricultural and agro-industrial by-products for ruminant feeding

Fifty-seven by-products were collected from regions throughout Brazil. Chemical composition, in vitro neutral detergent fiber digestibility (IVNDFD), and total digestible nutrients (TDN) were determined with the objective of grouping by-products with similar nutritional characteristics. The by-products belonging to group one (G1) presented the highest content of neutral detergent fiber exclusive of ash and nitrogenous compounds [aNDFom(n)] and lowest energy content, with 42.5% and 38.8% of IVNDFD and TDN, respectively. A new cluster analysis was carried in order to better characterize G2 by-products, six subgroups (SGs) were established (SG1 to SG6). SG1 by-products had the highest and the lowest values for lignin and TDN, respectively. SG2 by-products had the highest aNDFom(n) value, with TDN and IVNDFD values greater than 600 and 700g/kg, respectively, and crude protein (CP) value below 200g/kg in dry matter (DM). Among all the subgroups, SG3 had the highest TDN (772g/kg) and IVNDFD (934g/kg) values and the lowest lignin (23g/kg in DM) value. The ether extract was what most influenced the hierarchical establishment of residual grouping in SG4. SG5 by-products had the highest concentration of non-fibrous carbohydrate. Different from the other subgroups, SG6 by-products had the highest value of available CP.

Effects on animal performance and fat composition of two fat concentrates in diets for growing-fattening bulls

Two experiments were carried out with growing-fattening bulls, offered a fattening diet based on concentrate and supplemented with soya oil or steam-flaked linseed. Soya oil (200 g/kg) was mixed with middlings (800 g/kg). Linseed (500 g/kg) and whole barley (500 g/kg) were steam flaked. The fat incorporation resulted in an increase of the ether extract content from 26·5 g/kg dry matter to about 45 g/kg. The incorporation of soya oil increased the average daily gain (P> 0·05). The saturated: unsaturated fatty acid ratio was reduced in perirenal fat due to an increase of oleic acid and a reduction of stearic acid. The inclusion of steam-treated linseed resulted in a lower slaughter weight (P< 0·05) and a shorter fattening period (P> 0·05). The fatty acid composition of perirenal fat was affected significantly: the concentrations of oleic, linoleic and linolenic acid were increased and the concentrations of myristic, palmitic and stearic acids were reduced. This resulted in a reduced saturated: unsaturated fatty acid ratio.

In a third experiment, samples of the two fat concentrates were incubated in nylon bags in the rumen. The ether extract disappearance was high with both concentrates. Furthermore, the fatty acid composition was altered to a large extent for soya oil while large proportions of unsaturated fatty acids were still present with steam-flaked linseed.

A note on the apparent digestibility and nutritive value of whole cottonseed given to sheep

Four castrated crossbred (Karagouniki♂ × Friesian♀) rams were used in a 4 × 4 Latin-square design to determine the apparent digestibility of four diets based on alfalfa hay and maize grain and containing varying proportions of whole cottonseed (WCS). The proportions of WCS studied were 0, 175, 355 and 530 g/kg diet dry matter (DM) and the respective apparent digestibility coefficients of DM were 0·744, 0·716, 0·689 and 0·625; of organic matter, 0·772, 0·739, 0·718 and 0·643; and of neutral-detergent fibre (NDF), 0·409, 0·481, 0·522 and 0·472. The gross energy (GE) apparent digestibility coefficients were 0·745, 0·722, 0·704 and 0·641, for the same order of treatments. The effect of the incorporation of WCS instead of maize grain in the diet in significantly reducing DM, OM and GE digestibility was evident. The lowest digestible energy value of WCS was observed in the treatment with the highest level of WCS.

Efeito do nível de caroço integral de algodão sobre o consumo e digestibilidade aparente da fração fibrosa do feno de braquíaria (Brachiaria decumbens) em ovinos

Avaliou-se o efeito da inclusão de níveis crescentes (0, 12, 24, 35 e 49%) de caroço de algodão ao feno de braquiária (Brachiaria decumbens) sobre o consumo e digestibilidade da fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose e celulose em ovinos. Foram usados 25 carneiros sem raça definida, adultos, castrados e alojados em gaiolas metabólicas e distribuídos inteiramente ao acaso entre os tratamentos. Não houve diferença entre os tratamentos quanto ao consumo e coeficiente de digestibilidade da FDN. O coeficiente de digestibilidade da FDA foi similar entre os tratamentos exceto no tratamento com inclusão de 49% de caroço de algodão. O coeficiente de digestibilidade da celulose comportou-se de forma semelhante ao da FDA. O coeficiente de digestibilidade da hemicelulose dos tratamentos com caroço de algodão foi maior do que o do tratamento sem caroço de algodão.