Prolificity of Portuguese Serrana Goats between 1987 and 2015

Abstract

ObjectiveTo evaluate the prolificity of Serrana goats and their four ecotypes (Transmontano, Jarmelista, Ribatejano and Serra) as well its monthly distribution according to parity. MethodsData (n = 316610 parturitions) were recorded from 1987 to 2015 and obtained from the pedigree book of Serrana goats for all four ecotypes. The period (month and year) of parturition, females' parity and normal or abnormal parturitions, including abortions, were considered as independent variables. The dependent variable prolificity was calculated by the following formula: number of born kids/parturition. ResultsIt was observed an average prolificity of 1.47; from parity order 1 to parity order 5 prolificity increased from 1.33 to 1.57 (P < 0.001). The Ribatejano (n = 45925), Jarmelista (n = 31723), Transmontano (n = 238106) and Serra (n = 856) ecotypes showed prolificity averages of 1.60, 1.54, 1.44, and 1.35 (P < 0.001), respectively. Globally, and regarding the monthly kidding distribution for multiparous and nulliparous females of Transmontano, Jarmelista and Ribatejano ecotypes, it was also observed for parturitions from December and forward a decrease on prolificity with the minimum value being achieved in April (P < 0.001). ConclusionThese results suggest that females bred in July/August and October could be negatively affected by factors such as feed availability, environmental constraints and management conditions, with impacts on reproductive performance, namely on prolificity, which should be more investigated. Our study allows us to state that the Ribatejano and Jarmelista ecotypes presented higher prolificity than Transmontano ecotype probably due, in part, to genetic differences.