Evaluating reproductive outcomes in Saanen and Alpine doelings with suboptimal live weight and performance of their progeny
2025
Luisa E.S. Hernández-Arteaga | Juan M. Vázquez-García | Manuel J. Flores-Najera | Venancio Cuevas-Reyes | Miguel Mellado | Reagan Sims | Brian Bruner | Jaime M. Cavazos-Galindo | Cesar A. Rosales-Nieto
Aim of the study: This study aimed to evaluate the reproductive performance of Saanen and Alpine doelings with suboptimum live weight and the productive performance of their progeny. Area of study: The study was conducted at the Goat Unit of the Facultad de Agronomia y Veterinaria of the Autonomous University of San Luis Potosi. Material and Methods: Eight- to ten-month-old doelings (Alpine: n=63; Saanen: n=36) were induced to ovulate with exposure to vasectomized bucks and bred with natural service for two reproductive cycles (42 days). Pregnancy status, prolificacy, and reproductive rate were calculated. Doelings did not receive a nutritional supplement to enhance growth rates. Data were analyzed by binomial or multinomial distribution. Main results: Sixty-six percent of goats conceived, and a higher proportion conceived in their first reproductive cycle (86%; p < 0.001) after joining to bucks. Conception age differed between breeds (Alpine: 293±3 d; Saanen: 283±5 d; p < 0.05) but not live weight (Alpine: 23.5±0.5 kg; Saanen: 24.8±0.8; p > 0.05). Fertility (Alpine: 68%; Saanen: 61%), prolificacy (Alpine:14%; Saanen:23%), and reproductive rate (Alpine: 87%; Saanen:8 9%) did not differ between genotypes. Progeny birth weight (Alpine: 2.8±0.1 kg; Saanen: 3.0±0.1kg), body mass index (Alpine: 0.29±0.01; Saanen: 3.0±0.1 points), daily weight gain (Alpine: 172±9 g/d; Saanen: 171±8 g/d) and weaning weight (Alpine: 11.6±0.5 kg; Saanen: 11.4±0.4 kg) did not differ (p > 0.05) between genotypes. Six stillborns and seven postnatal deaths occurred. On average, the kid´s postnatal death was at 25±8 d with no difference between litter size or sex of goat kids between genotypes (p > 0.05). Research highlights: We concluded that Saanen and Alpine doelings with suboptimum breeding weight can be successfully bred at nine months of age and kidded at fourteen months of age. The fertility rate was acceptable, but most doelings kidded single offspring. The offspring’s live weight was below the average, and the mortality rate was below 10%. Further research is needed to elucidate the milk yield and composition and the consecutive reproductive performance of these doelings, especially when they are only 14 months of age.
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