Requirements of protein for maintenance and growth in ram hair lambs

• Published in: Tropical animal health and production 2016-10, Vol.48 (7), p.1323-1327
• Main Authors: Pereira, Elzania Sales, Fontenele, Rildson Melo, de Medeiros, Ariosvaldo Nunes, Oliveira, Ronaldo Lopes, Campos, Ana Claudia Nascimento, Heinzen, Eduardo Luiz, Bezerra, Leilson Rocha
• Format: Article
• Language: English
• Subjects: Animal Feed - analysis; Animal Nutritional Physiological Phenomena; Animals; Animals, Newborn; Biomedical and Life Sciences; Body Composition; Body Weight; Brazil; Diet - veterinary; Dietary Proteins - administration & dosage; Dry matter; Energy Metabolism; Hair; Life Sciences; Male; Regular Articles; Sheep - physiology; Tropical Climate; Tropical environments; Veterinary Medicine/Veterinary Science; Weight Gain; Zoology
• ISSN: 0049-4747; 1573-7438
• DOI: 10.1007/s11250-016-1091-9

The experiment was conducted to determine the protein requirements for maintenance (PM) and weight gain (NPg) in Brazilian Somali lambs ( n  = 48). A database of information on non-castrated rams ( n  = 48) with an initial body weight (BW) of 13.47 ± 1.76 kg was obtained, and the comparative slaughter technique was used to assess protein requirements. Eight lambs were initially slaughtered and used as a reference for estimation of the empty body weight (EBW) and initial body composition of the remaining animals. The lambs ( n  = 40) were distributed in a completely randomized block design involving five experimental diets, containing 4.93, 8.65, 9.41, 10.12, and 11.24 MJ/kg dry matter (DM). Daily nitrogen retention (DNR) was calculated as the difference between the final N content in the body minus the initial content estimated from the reference animals, divided by the number of experimental days. PM was estimated from the retained N regression equation as a function of ingested N (g per kg 0.75 EBW/day), extrapolating the equation to the zero level of N intake, followed by multiplication by a factor of 6.25. The protein content of the EBW was reduced from 119.72 to 102.07 g/kg of empty body weight gain (EBG) when BW increased from 13 to 28.70 kg, respectively. The requirement of protein for maintenance was 0.80 g per kg 0.75 EBW/day. Based on information described in the present study, we recommend the value of PM 0.80 g per kg 0.75 EBW/day, for hair sheep Brazilian Somalis raised in tropical regions. We also suggest that hair sheep have different requirements for protein maintenance and gain.