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

Abstract

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° 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.

Terminal Crossbreeding of Murciano-Granadina Goats with Boer Bucks: Characteristics of the Carcass and the Meat

“…On the other hand, the feeding of the kids in the present work was carried out using a freely available milk substitute, which had 35 mg of Fe/kg of DM. Mestizo kids had a higher growth rate and a higher daily consumption of milk than MG kids (224.2 vs. 189.1 g/d) [ 7 ]; therefore, it also represents a higher daily intake of Fe, which could have produced a slightly redder colouration of the meat. Colour is the only aspect of the meat that the consumer can evaluate in sales stalls, and they relate it to its sensory qualities [ 65 ], which is why it has great commercial importance [ 66 ].…”

“…In a previous work (Pérez-Baena et al [ 7 ]), at the experimental farm of the Spanish Universitat Politècnica de València, 70 multiparous (2.8 ± 0.2 years) healthy Murciano-Granadina (MG) goats, weighing 47 ± 1.5 kg on average, were divided into two groups of 35 animals of similar age and body condition (2.5–3). One of the groups was randomly assigned to mate with MG males (n = 4), producing purebred kids (MG), and the other group was assigned to mate with Boer males (n = 4), producing crossed Murciano-Granadina × Boer (MB) kids.…”

“…Ninety-four kids of 4 types (KT) were used: MG males (25), MG females (19), crossed MB males (25) and crossed MB females (25). The handling of the animals and the productive results can be consulted in [ 7 ]. All of these kids were used in this experiment to study the performance of the carcass, its morphological characteristics, the cutting of the carcass, the Longissimus thoracis et lumborum (LTL) muscle, the pH and the meat colour, but for the study of the tissue composition of the carcass and other meat characteristics, including a sensory analysis, only 15 randomly selected animals of each type were used.…”

“…In Spain, the breed of goats most frequently used is the Murciano-Granadina (MG), which has a domestic goat population of about 500,000 animals [ 4 ], with an average milk production of 547 kg in 210 days of lactation, containing 5.47% fat and 3.52% protein [ 5 ]. It has an adult size of 45–55 kg in females and 60–70 kg in males [ 6 ], with good average prolificacy (2.1), low birth weight (2.25 kg) and a low growth rate during lactation (114 g/day) [ 7 ]. The breed has a high dairy aptitude, but its qualities for meat production are more limited, so the sale of kid meat represents around 10% of the total income of the farm and may not even compensate for the costs involved [ 8 ].…”

“…An alternative used to improve meat production in goats consists of crossing the local breed with Boer males, which is a breed that enjoys worldwide recognition for its excellent body conformation, rapid growth rate and good carcass quality [ 9 ]. In some large breeds, such as the Kiko, crossing with the Boer breed does not improve the growth of kids [ 10 ], but in the MG breed, Pérez-Baena et al [ 7 ] showed that crossbreeding improved birth weight, the survival of offspring and the growth and conversion rates of kids during lactation, so production costs are reduced. Consequently, these authors considered the crossbreeding of MG females with Boer males to be of interest for the production of suckling kids.…”