The effect of dietary crude protein level on intake, growth, protein retention and utilization of growing male Saanen kids Tegene Negesse a,* , M. Rodehutscord b , E. Pfeffer c a Department of Animal Production and Rangeland Management, Awassa College of Agriculture, Debub University, P.O. Box 5, Awassa, Sidamo, Ethiopia b Institute of Nutrition Sciences, University of Halle-Wittenberg, 06099 Halle, Germany c Institute of Animal Nutrition of Bonn University, D-53 115 Bonn, Germany Accepted 17 August 2000 Abstract The effects of increasing dietary levels of crude protein on growth, feed intake, feed ef®ciency and composition of gain in male Saanen kids were studied. Four groups of four kids each initially weighing 12:1  0:18 kg and having a weight gain of 195  16 g/d were penned individually and fed for 73 to 124 days up to 25 kg of BW. They were fed chaffed wheat straw (45 g CP/kg DM) which had been molasses sprayed (10%) and pelleted concentrates containing 8.7, 11.7, 14.4 and 17.6% crude protein (CP) on DM basis, the ratio of straw to concentrate being 1:5. Kids were fed controlled to satiation in which case small amounts of the feeds were offered about ®ve times a day as long as the kids wanted to eat. Retention of protein, fat and energy were calculated from their initial and ®nal concentrations in the empty body homogenates of the slaughtered kids. With increasing CP level in the diet, feed intake increased from 448 to 608 g DM/d, weight gain from 94 to 181 g/d, retention of protein from 9.7 to 27.8 g/d, retention of fat from 9.6 to 19.1 g/d and feed ef®ciency improved from 4.79 to 3.39 kg DM/kg weight gain. Protein composition of gain increased from 103 to 154 g/kg BWG while fat (103±105 g/kg BWG) remained constant. Regression analyses showed that BWG can be optimized at 136 g CP/kg DM and protein retention at 180 g CP/kg DM, whereas, dietary nitrogen was utilized most ef®ciently at 120 g CP/kg DM. Extrapolated from the regression equations, maintenance N requirement of the kids at zero N-retention and at zero BWG were 0.38 and 0.16 g N/kg W 0.75 , respectively. Recommended dietary CP concentrations and maintenance N requirements depend on the traits desired. # 2001 Elsevier Science B.V. All rights reserved. Keywords: Intake; Kids; Nitrogen; Protein; Retention 1. Introduction The increasing cost of protein and environmental pollution due to emission of ammonia into the atmo- sphere from degradation of urea in excreta demands the determination of optimum levels of dietary protein for animals to avoid unnecessary loss of nitrogen, optimize production and minimize costs of feed and risk of environmental pollution. In contrast to sheep, for which a large amount of data on nutrient require- ment and nutritive value of feed-stuffs is available, corresponding information on goats is limited. In a published review of AFRC (1997), it was stressed that some of the earlier recommendations of the supply of nutrients made for goats by different authors were not adequately substantiated with experimental data. Small Ruminant Research 39 (2001) 243±251 * Corresponding author. Tel.: 2516-200221; fax: 2516-200072. E-mail address: ACA@telecom.net.et (T. Negesse). 0921-4488/01/$ ± see front matter # 2001 Elsevier Science B.V. All rights reserved. PII:S0921-4488(00)00193-0