Agronomic characterization of sunflower cultivars for animal feeding in tropical conditions

This study was developed to examine morpho-agronomic traits of 18 sunflower cultivars and identify superior cultivars in terms of grain yield, forage quality, or both, for animal feeding. Twenty-two morpho-agronomic traits related to plant development and architecture; earliness of maturity; grain yield (achenes); dry matter yield; and dry matter content were evaluated. Cultivars Hélio 253, Hélio 358, Embrapa 122, BRS 321, and Hélio 360 showed inflorescence at the final stage. Aguará 4 showed the lowest flowering rate, characterizing it as late-maturing. For grain yield, cultivars Charrua, Olisun 3, BRS 321, Paraíso 103CL, Paraíso 65, Aguará 6, and CF 101 are recommended, as they showed the highest achene yields (average: 1,541.67 to 2,148.81 kg.ha−1, respectively). Cultivars Charrua, Hélio 251, Olisun 3, Hélio 360, Paraíso 55, and Paraíso 103CL exhibited higher dry matter yields (9,550.93 to 11,789.91 kg ha−1) and were thus indicated for forage production. Cultivars Charrua, Olisun 3, BRS 321, Paraíso 103CL, Paraíso 65, Aguará 6, and CF 101 are recommended for grain yield, for the diet of monogastric animals; Charrua, Hélio 251, Olisun 3, Hélio 360, Paraíso 55, and Paraíso 103CL for forage yield, for ruminant feeding; and Charrua, Olisun 3, and Paraíso 103CL for both purposes.

Intake, digestibility and nitrogen utilization in cattle fed tropical forage and supplemented with protein in the rumen, abomasum, or both.

BACKGROUND: There is little information in the tropics with regard the comparative understanding of how an increased nitrogen supply in the rumen or in the intestines affects efficiency of nitrogen utilization in cattle. This study evaluated the effects of supplementation with nitrogenous compounds in the rumen, abomasum, or both on intake, digestibility and the characteristics of nitrogen utilization in cattle fed tropical forage. Four rumen- and abomasum-fistulated Nellore bulls (227 ± 11 kg) were used. Four treatments were evaluated: control, ruminal supplementation (230 g/d of supplemental protein in the rumen), abomasal supplementation (230 g/d of supplemental protein in the abomasum), and ruminal and abomasal supplementation (115 g/d protein in both the rumen and the abomasum). The basal forage diet consisted of Tifton 85 hay with a crude protein (CP) level of 78.4 g/kg dry matter. Casein was used as a supplement. The experiment was conducted using a 4 × 4 Latin square. RESULTS: There were no differences between the treatments (P > 0.10) with regard to forage intake. The intake and total digestibility of CP increased (P < 0.01) with supplementation. The nitrogen balance in the body increased (P < 0.01) and muscle protein mobilization decreased (P < 0.01) with supplementation, regardless of the supplementation site. The efficiency of nitrogen utilization did not differ among the treatments (P > 0.10). CONCLUSIONS: The supplementation of cattle fed tropical forage with protein in the rumen, abomasum, or both similarly increased the nitrogen accretion in animal, which reflects improvements on nitrogen status in animal body.

Cinética da degradação ruminal de dietas contendo farelo de casca de pequi / Ruminal degradation kinetics of diets with pequi hulls bran

A casca de pequi é um resíduo do processamento do fruto, encontrado em grande volume nas regiões do cerrado brasileiro, que pode constituir uma alternativa para a alimentação de ruminantes. Avaliou-se a cinética da degradação ruminal da matéria seca (MS), proteína bruta (PB) e fibra em detergente neutro (FDN) do farelo da casca de pequi (FCP) e de dietas contendo diferentes níveis do resíduo em substituição ao capim-elefante (CE). Foram utilizados quatro caprinos, machos, portando cânulas ruminais, dispostos em um delineamento experimental de blocos ao acaso com parcela subdividida. Avaliaram-se os parâmetros de degradabilidade do FCP, capim-elefante e de dietas contendo 0, 10, 20 e 30 por cento de FCP em substituição ao CE. Os alimentos foram incubados no rúmen nos tempos de 4, 8, 12, 24, 48, 72 e 96 horas. Os resultados indicaram degradação potencial da MS, PB e FDN do resíduo superiores a 90, 80 e 80 por cento, respectivamente. A adição do FCP em substituição ao CE resultou em maior degradabilidade da matéria seca e fibra em detergente neutro, reflexo da maior fração solúvel e potencialmente degradável da MS do FCP. Para a fração protéica, a adição de FCP correlacionou-se negativamente com a fração solúvel, degradação potencial e efetiva, e positivamente com a fração insolúvel potencialmente degradável. A substituição do capim-elefante por FCP permite melhor aproveitamento da dieta, elevando o aporte de nutrientes ao animal.

The pequi hulls is a waste of pequi processing, found in large volume in the Brazilian Cerrado, which may provide an alternative to ruminants' diet. This experiment was developed to evaluate the ruminal degradation kinects of dry matter (DM), crude protein (CP) and neutral detergent fiber (NDF) of pequi hulls bran (PHB) and experimental diets, with different substitution levels of elephant grass (EG) by pequi hulls bran. Four goats castrated with ruminal cannulas were used in a randomized complete block as experimental design. It was evaluated the ruminal degradation of PHB, elephant grass and four diets with 0, 10, 20 e 30 percent of PHB in substitution to elephant grass. The feeds were incubated in the rumen at times 4, 8, 12, 24, 48, 72 and 96 hours. The results showed that the PHB had high degradation potential DM, CP and NDF, over 90, 80 and 80 percent respectively. The addition of the PHB, replacing the EG, resulted in a higher degradability of dry matter and neutral detergent fiber, because the pequi waste had higher soluble and potentially degradable fraction of DM than elephant grass. The PHB addition was negatively correlated with the soluble CP and with the potential and effective degradation of the CP, and positively correlated with insoluble potentially digestible CP. The EG substitution for PHB allows better utilization of the diets, increasing the nutrient supplies to the animal.