Palma forrageira na alimentação de cabras leiteiras

Abstract

The objective was to evaluate the use of the cactus and the replacement of the Miúda spineless cactus (Nopalea cochenilifera Salm-Dyck) with the Orelha de Elefante Mexicana spineless cactus (Opuntia strica [Haw]. Haw) on nutrients intake and digestibility, ingestive behavior, water intake, microbial protein synthesis, production and quality of milk and rennet cheese of the lactanting Saanen goats. Ten lactating Saanen goats (5010 kg body weight) were used, divided into primiparous and multiparous, with milk production averages of 3.5 kg/day, distributed in a 5 x 5 Latin double square. The experimental period lasted 95 days divided into five periods of 19 days each, with the first 14 for adaptation of the animals, followed by five days for data collection and samples. The experimental diets were composed of the following treatments: Control treatment (Tifton hay base and concentrate); 0; 11.5; 23.5 and 35% replacement levels of the Nopalea cactus by Opuntia cactus, based on dry matter. The dry matter (DM), organic matter (OM), crude protein (PB) and total digestible nutrients (NDT) intake did not suffer an effect (p> 0.05) from the replacement of the Nopalea cactus by the Opuntia cactus, however, the intake of neutral detergent fiber corrected for ash and protein (NDFcp) and non-fibrous carbohydrates (CNF) were affected (p <0.05) by the substitution. The Opuntia cactus provided greater (p <0.05) digestibility of MS MO and CNF in relation to the control treatment and the diet with 35% Nopalea cactus. Diets with Opuntia and Nopalea cactus increased milk production (3.294 and 3.440 kg/day) and fat-corrected milk production (3.5%) (3.018 and 2.729 kg/day). The highest water intake from feed (p <0.05) was observed in 35% Nopalea cactus diet (7.324 kg/day) and Opuntia (5.921 kg/day), consequently the highest intake of drinking water was observed in the control diet (9.450 kg/day). The dismissed feeding time (FT), rumination time (RT) and total chewing (TC) were lower (p <0.05) for treatments with cactus, so that the idle time (IT) was higher (p <0.05) for diets with Nopalea and Opuntia, in addition to providing greater (p <0.05) feeding efficiency (FE), rumination (DM and NDF) compared to the diet without cactus. The nitrogen balance and microbial protein yield were not altered (p> 0.05) due to the replacement of the Nopalea cactus by Opuntia. There was variation in the content of total milk solids, the diets with Nopalea showed lower content (9.91) compared to the control diet (10.12). The protein, lactose and casein contents underwent a quadratic effect (p <0.05). There was variation in the physical-chemical composition of the cheese for the levels of fat, protein, pH and yield, the diets with cactus decreased the levels of fat concerning to the control diet whose average values were 20.21% (Opuntia), 21.30% (Nopalea) and 22.70% (control). However, protein contents were higher for diets with Opuntia cactus (20.82%) compared to the control diet (16.92%). The control diet promoted greater cheese yield compared to diets with cactus. Goat rennet cheese fed with Opuntia cactus according to the scores for appearance, flavor, texture and overall evaluation represented good acceptance by the tasters. In the purchase intention test there was acceptance for Saanen goats' milk rennet cheeses fed with Opuntia and Nopalea cactus.