Cabras Saanen Primíparas e Multíparas: Prolificidade, produção e composição do leite e curva de Lactação

Abstract

One of the characteristics that determine the efficiency of the production system is prolificity. In addition, factors such as nutrition, persistence of lactation and order of birth can contribute to the quantitative and qualitative characteristics of milk, making the production system more viable. In this sense, the objective was to evaluate the prolificacy, milk yield, milk composition and lactation curve of primiparous and multiparous Saanen goats. Twenty lactating Saanen goats (508,27 kg body weight) were used, divided by calving category, being 8 primiparous and 12 multiparous, with an average production of 3.5 kg of piglet corrected for 3.5% fat. The experimental diet was formulated to meet the nutritional requirements of lactating goats, consisting of forage palm, hay and concentrate in a ratio of 50:50 roughage / concentrate. After delivery, information on calving order, weight and sex of the offspring were collected. The milking was performed twice a day and the individual daily productions were computed. For analysis of the lactation curve as a function of delivery, the model proposed by Wood was used and for analysis of milk yield and composition, a variance analysis was performed using the linear model procedure and comparison of means using the Tukey test. at 5% probability. The prolificacy values found for Saanen goats were 1.67 for primiparous goats and 1.93 for multiparous goats. There was no significant difference (P> 0.05) in the order of delivery for fat, protein, lactose, total solids, non-fat solids contents. However, for milk production there was a significant effect (P <0.05), the multiparous (3.20 kg) presented higher average production when compared to the primiparous (2.60 kg), similarly the Somatic cells (SCC) showed significant effect (P <0.05), where multiparous goats had higher rates. Regarding the results obtained for lactation curves, the estimated lactation peak was 58 days with an average production of 3.14 kg, while according to the observed data the lactation peak occurred at 71 days with an average production 3, 26 kg for primiparous goats. In the multiparous, we observed that the estimated lactation peak was 29 days with an average production of 3.99 kg, while the observed data the peak lactation occurred at 60 days with an average production of 3.94 kg. Primiparous and multiparous Saanen goats presented excellent prolificacy rates, with higher milk yield observed in multiparous, however in the lactation curve the primiparous showed higher productive persistence.