Substituição da cana-de-açúcar por palma orelha de elefante mexicana em dietas para vacas em lactação

Abstract

The cactus cladodes [Opuntia Stricta (Haw). Haw] is an adapted plant to our edaphoclimatic conditions on arid and semiarid regions and shows very good performance in forage production per hectare. This cactus cladodes clone has been an alternative instead other cactus cladodes clones used by cattle ranchers at the Agreste region in Pernanbuco, Brazil. Nevertheless, very few researches regarding its benefits on dairy cattle feeding system are available. Based upon this, the main objective was to evaluate intake and digestibility of nutrients, ingestive behavior and the milk yield and composition of dairy cattle fed with sugarcane in association with cactus cladodes [Opuntia Stricta (Haw). Haw]. Ten Holsteins lactating cows were distributed into two Latin square design 5x5, and were fed four different replacement levels of sugarcane for cactus cladodes (0; 17.2 34.4 and 51.6%) plus concentrate feed. A control diet based on sorghum silage (IPA-SF15) plus concentrate was also used. Related to the replacement levels, the intakes of dry matter, organic matter, non-fiber carbohydrates, crude protein and total digestible nutrients (TDN) presented an quadratic response (21.03; 19.43; 3.16; 9,88; and 14.19 kg/day estimated with 30.8; 28.83; 29.38; 32.21; and 28.36% of cactus replacement level, respectevely). Feeding time decreased and the idleness time increased with replacement. Nitrogen balance was not altered. Milk yield correct for 3.5% of fat or not presented a quadratic response with the replacement (23.60 and 26.05 kg/day estimated with 34.64 and 37.87%, respectively). The content of crude protein and total solids increased, while the content of fat and lactose were not altered. To maximize milk yield is recommended replacement of 37.87 % of sugarcane for cactus cladodes [Opuntia Stricta (Haw). Haw] on diets with 36% of concentrate feed.