Maintenance energy requirements of Criollo and Saanen goats

SBRIGLIO, L.; VALLI, F.; ALLEGRETTI, L.; VAZQUEZ NOVOA, E.; PAEZ LAMA, S.; EGEA, V.

Mendoza

Otro; XXVI Reunión Científica Anual de la Sociedad Biológica de Cuyo; 2018

In Argentina, goat production is carried out mainly under extensive conditions in natural grasslands. Criollo goats are the most common breed and the main products obtained are suckling kids for human consumption. The Criollo goats have adapted for centuries to the rigorous agro-ecological conditions of arid zones. For several years, indiscriminate crosses have been practiced with exotic breeds, such as Saanen of high milk production, with the aim of increase the milk productivity of Criollo breed. However, these exotic breeds are usually unable to adapt and demonstrate their genetic potential in arid and semi-arid areas. This could be due, among other factors, to the fact that high production breeds have very high nutritional requirements, as energy needs. Therefore, it is necessary to evaluate different physiological characteristics of exotic breeds and their crosses before their diffusion in traditional Argentinean goat production systems. The objective of this research was to determine the maintenance energy requirements in Criollo and Saanen goats under stabling conditions. Five goats of each breed were individually housed and fed with alfalfa pellets for 8 weeks. To determine energy requirements, adjustments were made in the food supply until achieving dry matter consumption (DMIm) that maintains constant bodyweight (BW is bodyweight and BW0,75 is metabolizable bodyweight ). Animals were weighed twice a week and adjustments in the offer were made according to the changes in BW in the immediate previous period. The maintenance energy expenditure (MEm) was estimated with the DMIm value and the metabolizable energy (ME) concentration of the ration. The nutritional composition on dry matter (DM) basis of alfalfa pellet was: 16,7 % Crude protein; 36,8 % Neutral detergent fiber, 31,8 % Acid detergent fiber, 9,3 % ash; and 2,1 Mcal kg DM-1 of ME. The BW of Saanen goats (49,1 ± 1,2 kg) was higher (p < 0,05) than that of Criollo goats (43,4 ± 0,9 kg). No differences were found (p > 0,05) in the DMIm between Criollo (53,9 ± 3,6 g kg BW0,75 d-1) and Saanen (45,4 ± 2,8 g kg BW0,75 d-1) goats. The MEm requirements for Criollo goats were 106,7 kcal ME kg BW0,75 day-1; while for Saanen goats were 97,0 kcal ME kg BW0,75 day-1. No differences were found in maintenance energy requirements between Criollo and Saanen breeds. This could be due to the fact that diet energy availability was not limiting, as in low energy diets, where goats could reduce their metabolic rate and energy requirements differentially between breeds. However, this should be checked under other test conditions, mainly with diets with lower energy availability.