Resumo

ARIAS-GAMBOA, Luis Mauricio et al. Milk production and bromatological quality and costs of supplementation with Tithonia diversifolia (Hemsl.) A. Gray, in Jersey cows. Pastos y Forrajes [online]. 2018, vol.41, n.4, pp. 266-272. ISSN 2078-8452.

In order to evaluate the milk production and bromatological quality, and the costs of supplementation with three levels of Tithonia diversifolia (Hemsl.) A.Gray, a trial was conducted in the Santa Lucía farm of the National University of Costa Rica. Nine Jersey cows were used in a replicated 3 x 3 Latin square. The animals were fed with a diet based on Cynodon nlemfuensis Vanderyst under grazing conditions and supplementation with Cenchrus purpureus (Schumach.) Morrone, molasses, Digitaria decumbens Stent hay, minerals and urea. Three treatments were evaluated: TD0, Grazing + Balanced feed (BF); TD25 (Grazing + substitution of 25 % of the BF by T. diversifolia forage), and TD50 (Grazing + substitution of 50 % of the BF by T. diversifolia). Milk production, bromatological quality and supplementation costs were evaluated. The data were analyzed through a variance analysis. In TD25 a production of 21,4 kg/animal/day was reached without significant differences with regards to TD0. In TD50 the milk production showed a decrease of 8,7 and 11,2 % compared with TD0 and TD25, respectively. The bromatological composition did not show significant differences between TD0 and TD25, while TD50 differed (p < 0,05) for protein (32,5 g/kg) and non-fatty solids (82,7 g/kg), compared with TD0. The use of T. diversifolia as supplement of dairy cows allowed to save 0,25 and 0,52 USD animal/day in treatments TD25 and TD50, respectively. It is concluded that the substitution of 25 % of the balanced feedstuff by T. diversifolia forage did not affect milk production and bromatological quality in Jersey cows, and it also saved 9,06 % due to the decrease of supplementation costs.

Palavras-chave : shrubs; dairy cattle; milk production; protein.

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