Maintenance and growth requirements for energy and nitrogen of Baluchi sheep

• Published in: International journal of agriculture and biology Vol. 9; no. 4; pp. 535 - 539
• Main Authors: Kamalzadeh, A. (Ministry of Jihad-e-Agriculture, Tehran (Iran). Animal Sciences Research Inst.), Shabani, A. (Deputy Ministry for Livestock Affairs, Tehran (Iran). Animal Nutrition Section)
• Format: Journal Article
• Language: English
• Published: 01.07.2007
• Subjects: ANIMAL FEEDING; BREEDS (ANIMALS); CONCENTRATES; ENERGY METABOLISM; FEED INTAKE; GROWTH; NITROGEN; NUTRITIONAL REQUIREMENTS; SHEEP; WEIGHT GAIN
• ISSN: 1560-8530; 1814-9596

Twenty-eight Baluchi male sheep [12 months old with mean body weight (BW) of about 35 kg] were used to measure maintenance (zero growth) and growth requirements of nitrogen and metabolizable energy (ME). The lambs were divided into two equal groups: maintenance (T) and a growth (G) group. The experiment had duration of 24 days adaptation period and 60 days treatment period. All animals were offered a diet based on pelleted concentrate mixture consisting of alfalfa, barley, cottonseed meal and barley straw and were individually placed in metabolism cages. During the experiment, animals of group G gained 222.4 g d-1, while the sheep of group T maintained a relatively constant live weight (- 0.2 g d-1). Nitrogen (N) and energy requirements were determined by both measured and regression methods. Animals of the T group stayed at about zero N balance (0.002 g.kg -0.75 d-1), whereas the N retention of G group was about 0.65 g.kg -0.75 d-1. Digestibl e organic matter intake (DOW) and energy requirement for maintenance were measured by both constant weight and regression method by regressing N balance on DOMI and ME intake on daily weight gain (DWG). The DOMI measured during constant weight and the DOMI calculated from regression equation were 21 and 20.81 g.kg -0.75 d-1, respectively. There was no significant difference between both measured and regression techniques. The measured ME for maintenance for T group during constant weight and the calculated ME for maintenance from regression method were 294 and 342 kJ.kg -0.75 d-1, respectively. The metabolizability values obtained in this experiment were 0.35 and 0.54 for groups T and G, respectively.