The response of highly productive rabbits to dietary sulphur amino acid content for reproduction and growth.

This study investigated the sulphur amino acid (SAA) requirements of rabbits. Five diets, containing 0.48-0.72% crude SAA, were formulated by supplementing a basal diet with DL-methionine. The apparent methionine digestibility (%) was 71.4 +/- 1.1 in the basal diet and 102.9 +/- 0.9 for DL-methionine, as estimated by the difference method. Feeding trials were carried out using 370 rabbit does and 1 195 weanling rabbits slaughtered at 2-2.1 kg body weight. Milk production was measured in 80 lactations. Carcass traits were determined in 125 rabbits. The dietary SAA content affected several productive traits, such as milk production, parturition interval, growth rate, carcass quality and feed efficiency. When the diets were compared using orthogonal contrasts, a minimum requirement of 0.54% crude or 0.40% digestible SAA was determined. Further responses in performance were observed, however, when the data were analysed by regression methods. The values of crude and digestible SAA for optimal production were, respectively, 0.63 and 0.49% (rabbit does) and, at least, 0.72 and 0.58% (growing rabbits).