Sistema alimentar de cabras em lactação como fator indutor da qualidade do leite.

Abstract

Innovating the goat's feeding system in the conditions of the semi-arid can be a means of aggregation of value to its products such as the quality, flavour and induction of beneficial substances to consumers ' health. In this context, it was aimed to evaluate feeding systems of lactating goats as a factor of inducing the quality of the milk, as well as its performance in the conditions of the semi-arid. Eighteen crossbred goats (Saanen and Alpine- american) were used for the experiment, distributed in a completely randomized design with three treatments. Experimental treatments consisted of: confined goats receiving diet with elephant grass hay and concentrate (CS); Goats in a confined system receiving diet with elephantgrass hay, concentrate and forage palm (PCS) and goats in a pasture system with supplementation of 1.5% in relation to body weight (SPS). Except for the NDF and TDN, the goats have diferente performance (P<0,05) compared to the rated feeding systems. In relation to the apparent digestibility, it differed from the EE, TCH and FNC differed, where the DEE was lower (P <0.05) for SCP goats compared to the other systems studied, and the apparent digestibility of THC and FNC was higher (P <0.05) for SCP goats. Ruminal pH values were within the optimum range for adequate fermentation in the ruminal environment. The observed N-NH 3 concentrations were not limiting for microbial growth. As for PL and PLCG 4% (kg / day), the SCP goats presented higher yields (P <0.05) than the other systems. Total protein, albumin, uric acid, glucose, AST, GGT, phosphorus, sodium and chloride were influenced in their concentration by the time of collection. In relation to the feeding systems, these differed (P <0.05), influencing the blood parameters with the exception of serum calcium. For the studied plant species, the phytochemical prospection verified the presence of relevant secondary metabolites, mainly steroids, flavonoids and tannins. The total phenol content in the milk did not show a significant difference (P <0.05), however the SPS animals obtained higher (P = 0.0443) concentrations of flavonoids when compared to the milk of SCP animals. The antioxidant activity presented significant difference only for DPPH, being higher (P = 0.0243) for SC animals than SPS. The milk of SCP-fed animals obtained higher concentrations of saturated fatty acids (SFA). The milk of SPS animals had a higher fat content when compared to the SCP system, besides having a higher quantity of polyunsaturated fatty acids (PUFA) and some monounsaturated fatty acids (MUFAs), including the monounsaturated C16: 1c7, the cis and trans isomers of C18: 1, linoleic acid (C18: 2n6) and linolenic acid (C18: 3n3). The diets also conferred sensorial changes in the milk for the parameters: characteristic taste, persistence and intensity after test and global acceptance. SCS milk was described with lower goat flavor, persistence and intensity after test, and the overall acceptance was higher than the other evaluated systems.