Intake, digestibility and intake behaviour in cattle fed different levels of palm kernel cake

ABSTRACT Objective. The potential use of palm kernel cake was evaluated as a replacement for soybean and corn meal in cattle feed, by investigating their intake, digestibility levels and the intake behaviour of cattle fed diets containing different levels of palm kernel cake concentrate. Materials and methods. The experiment was conducted at the Experimental Farm of the Federal University of Bahia, between August and October 2009. Five crossbred Holstein × Zebu adults, were used. A 5 × 5 Latin square experimental design was used. The animals were fed Tifton-85 Bermudagrass, which made up 65% of their diet, plus one of five different levels of palm kernel cake concentrate (0, 7, 14, 21 and 28%). Results. A linear decrease in dry matter (kg/day) was observed due to the lower palatability and higher fiber content of the palm kernel cake. Neutral detergent fiber intake by the animals showed a quadratic behavior. The coefficients of fractional digestibilities of the analyzed feed, did not differ due to the inclusion of palm kernel cake. The ingestive behavior of the animals was not influenced by the inclusion of palm kernel cake in the diet. Conclusions. Palm kernel cake can be used as an alternative feed supplement in ruminant production systems to reduce feed costs without changes in the studied variables

Degradabilidade ruminal da matéria seca, da fração fibrosa e da proteína bruta de forrageiras Forages dry matter, fibrous fraction and crude protein ruminal degradability

O objetivo deste trabalho foi avaliar a degradabilidade ruminal da matéria seca, da fibra em detergente neutro, da fibra em detergente ácido e da proteína bruta da alfafa (Medicago sativa), aveia-preta (Avena strigosa), leucena (Leucaena leucocephala) e guandu (Cajanus cajan). Amostras de 3 g das forragens foram incubadas no rúmen de três novilhos por períodos de 0, 6, 12, 24, 36, 48 e 72 horas. As degradabilidades efetivas da matéria seca da alfafa e da aveia, para a taxa de passagem de 5% por hora, foram elevadas (acima de 60%). A leucena e o guandu apresentaram valores inferiores, 50,9 e 56,0%, respectivamente. A partir de 24 horas de incubação, a aveia se destacou com maior desaparecimento da fibra em detergente neutro e da fibra em detergente ácido, e ainda apresentou as mais elevadas taxas de degradação efetiva destas frações. A aveia foi a forragem que apresentou maior degradabilidade da matéria seca, da fibra em detergente neutro, da fibra em detergente ácido e da proteína bruta no rúmen. O guandu, entretanto, foi a forragem com as piores taxas de degradação.<br>The objective of this work was to evaluate ruminal degradability of dry matter, neutral detergent fiber, acid detergent fiber and crude protein of alfalfa (Medicago sativa), black oat (Avena strigosa), leucaena (Leucaena leucocephala) and pigeon pea (Cajanus cajan). Samples of 3 g of forages were incubated in the rumen of three steers for 0, 6, 12, 24, 36, 48 and 72 hours periods. The dry matter effective degradabilities of alfalfa and oat, for a passage rate of 5%/hour, were high (over 60%). However, leucaena and pigeon pea showed lower values, 50.9 and 56.0%, respectively. From 24-hour incubation period on, the oat presented the highest neutral detergent fiber and acid detergent fiber disappearance and showed the greatest effective degradation rates of these fractions. The oat was the forage with the highest dry matter, neutral detergent fiber, acid detergent fiber and crude protein ruminal degradability. Pigeon pea, however, was the forage that showed the worst degradation rates