Terminal Crossbreeding of Murciano-Granadina Goats to Boer Bucks: Effects on Reproductive Performance of Goats and Growth of Kids in Artificial Rearing

Abstract

[EN] The Murciano-Granadina is one of the main goat breeds dedicated to milk production worldwide. However, kids of this breed are born with low birth weight and do not grow rapidly, so farmers have little interest in raising them for meat because of the low profitability they obtain. The aim of this work is to improve the growth characteristics of these kids by crossbreeding Murciano-Granadina goats with males of the Boer breed, which is considered the best meat goat breed. The results showed that crossbred kids have a higher birth weight (+24%) and, in artificial rearing until 9 kg live weight, have lower mortality (-37%), higher growth rate (+32%) and a better milk powder conversion rate (16%). However, when this crossbreeding is carried out in the anoestrous season (experiments conducted at latitude 38-39 degrees N), the reproductive performance of Murciano-Granadina females worsens slightly. It is concluded that the terminal crossbreeding of Murciano-Granadina goats to Boer bucks (those not used to produce replacement kids) could be an interesting option for ethical goat production.

The aim of this work was to improve the growth characteristics of Murciano-Granadina (MG) kids through terminal crossbreeding of MG goats to Boer bucks. Four experiments were carried out, using a total of 354 MG goats, half of which were mated with MG bucks (n = 12) and the other half with Boer bucks (n = 12). The kids were raised in artificial rearing until slaughter weight (9 kg). The birth weight and average daily gain were recorded in crossed kids (n = 197 and 145, respectively) and purebred kids (n = 257 and 169, respectively). Crossed kids presented significant differences (p < 0.001) compared to MG purebred kids in birth weight (+ 24%), mortality in artificial rearing (-37%), average daily gain (+32%) and milk powder conversion rate (-16%). However, the reproductive performance rates of MG goats mated with Boer bucks were slightly worse (pregnancy rate: 78.5% vs. 86.6%, p < 0.05; kidding rate: 62.0% vs. 75.7%; p < 0.01; prolificacy: 1.9 vs. 2.1 kids/parturition), especially when the matings took place in non-breeding season (experiments conducted at latitude 38-39 degrees N). It is concluded that the terminal crossbreeding of MG goats to Boer bucks (those not used to produce replacement kids) could be an interesting option for ethical goat production.