Silagem de grão de milho umidificado com diferentes aditivos em dietas para caprinos confinados em crescimento.

Abstract

The objective of this study was to evaluate the effect of replacing the dry ground corn grain by silages with the moisties additives, water, cactus pear mucilage and whey on intake, nutrient digestibility, nitrogen balance, ingestive behavior, animal performance, ruminal parameters and blood parameters of growing goats. Three experiments were performed. For the experiment I used 32 crossbred Boer goats, male, not castrated, with an average initial weight of 16.7 ± 5 kg and three months of age, distributed in a randomized block design with 4 treatments and 8 replications. For experiment II 12 crossbred Boer goats were used, male, not castrated with an average weight of 21.9 ± 1.5 kg and four months of age, distributed in a completely randomized design with 4 treatments and 3 replications. For experiment III, 4 adult, male, castrated Santa Inês sheep weighing 30.4 ± 6 kg, fistulated and cannulated in the rumen, distributed in a Latin square design (4 × 4) were used. The experimental diets consisted of 4 treatments, (1) dry ground corn (MMS); (2) silage of ground corn grain moistened with water (SMUA); (3) silage of ground corn grain moistened with cactus pear mucilage (SMUM) and (4) silage of ground corn grain moistened with whey (SMUS). All silages were included in the replacement of dry ground corn. Dry matter intake (DM; P= 0.004) was higher for SMUM when compared to SMUS. Crude protein consumption (CP; P= 0.005) and neutral detergent fiber consumption (NDF; P= 0.0002) were lower for SMUS in relation to other treatments. There was no significant difference for DM, CP and NDF digestibilities (P>0.05). The MMS showed the lowest N balance (P= 0.008) and the highest excreted N-urinary (P= 0.014) than the SMUA, SMUM and SMUS treatments. There was no significant effect for the observed variables of ingestive behavior (P>0.05). Diet influences animal performance with higher final body weight (P=0.033), total weight gain (P=0.004) and average daily gain (P=0.039) for MMS and SMUM. There was no effect between treatments on the feeding efficiency of goats (P>0.05). It was observed, higher albumin concentration for SMUM, SMUA and MMS (P= 0.0045) and higher concentration of chlorine for MMS, SMUM and SMUA (P= 0.0496), there was no significant difference between treatments (P>0.05) for the other biochemical variables. The lowest concentration of ammonia nitrogen N-NH3 was observed for SMUS (P=0.0067). It is recommended the use of moisties additives water and cactus pear mucilage, as a viable alternative of wetting additives for dry ground corn grain, for feeding of growing goats.