Suplementación pre y postparto durante la estación lluviosa en cabras locales del norte de México.

Grazing native vegetation does not satisfy the nutritional needs of the dairy goats, especially in early lactation. Therefore, there are strategies of food supplementation to increase milk production; most of the feed supplementation research has focused on meeting the needs of the drought period. However, it is necessary to evaluate whether in the rainy season the availability of forage species may cover the nutritional requirements of the goats, or at least the deficit is lower and therefore avoid unnecessary expenses in extra feeding. Therefore, the objective of this study was to evaluate the effect of pre-partum and post-partum concentrate supplementation and its effect on body weitgth, body condition, milk production and milk quality, in the early lactation and during the rainy season at the Comarca Lagunera in Northern Mexico. Method: There were used 33 adult local goats. a) Control group (control) (n = 11), which were fed exclusively with the forages collected by the animal in the grazing route. b) Pre kidding goat group (N = 11) who aditionaly to the pasture grazed were offered 500 g of commercial concentrate per animal and day, during 30 days before the kidding time and c) Postpartum group (n = 11) free pasture grazed plus 500 g of concentrate Commercial by animal and day during 30 days from the date of kidding time. The variables of body weight (PV) and body condition (CC) were measured weekly, during 14 weeks. Milk production and milk quality (Fat, Protein and Lactose) were measured weekly from the date of parturition during 8 weeks. The statistical analysis for milk production and quality variables were performed using the MIXED procedure. The PV and CC data were analyzed using the GLM procedure and the Tukey test fitted for the comparison of means was used. Concentrate consumption data were analyzed with a t-test to determine differences between supplemented groups. Results: There were no differences (p> 0.05) in the consumption of concentrate in the pre- and postpartum groups. There were found differences (p <0.05) in PV and CC prior to kidding time. Post partum the PV and CC were similar in all groups with losses until the end of the experiment. There were no differences (p> 0.05) in milk production, fat content, protein or lactose, nor effects of treatment * time interaction. Discussion: It is concluded, that supplement used one month before or after birth do not improve milk production, chemical composition of milk or body weigth from local goats in early lactation and rainy season under extensive grazing conditions in the Comarca Lagunera in northern Mexico. [ABSTRACT FROM AUTHOR]