Efeitos da eficiência placentária sobre o desempenho de cabritos

Abstract

The placenta is an organ of great importance for the development of mammals, being responsible for transferring nutrients from the mother to the young during the entire pregnancy. There are some factors that can influence the efficiency of the placenta, causing it to interfere or not with fetal growth. The objective of this study was to verify the relationship between lamb weight and survival until weaning and placental efficiency and other maternal and offspring characteristics For the analysis in which placental efficiency and survival until weaning were the dependent variables, and placental efficiency, number of offspring born, number of males and females born by parturition, weight and body condition score of mothers at parturition were the explanatory variables, Generalized Linear Models were used. To verify which characteristics influenced the dependent variable weaning weight, a linear regression was used, in which the explanatory variables were placental efficiency, mother's weight at parturition, number of offspring born at parturition, number of males and females born per parturition and mother's body condition score at birth. Placental efficiency increased with the number of offspring born. The weight of the weaning goats increased with each extra kilogram of the mother's weight at birth, with each extra kilo of born kid, and with each extra gram of born kid per gram of placenta. The number of goats until weaning increased with each more calf born per parturition and with each extra kilo of goats at parturition, but it decreased for each more gram of kid born per gram of placenta. The effect of placental efficiency was lower than that of maternal nutrition and prolificacy. In other words, to increase production efficiency, it would be more interesting to focus efforts on supplying the nutritional requirements of the sows both before breeding (thus ensuring greater prolificacy) and during pregnancy (ensuring the birth of heavier kids).