Energy and protein requirements for maintenance and growth of Boer crossbred kids1
Open Access
- 1 April 2007
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Animal Science
- Vol. 85 (4), 1014-1023
- https://doi.org/10.2527/jas.2006-110
Abstract
Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 ¾ Boer × ¼ Saanen crossbred, intact male kids (20.5 ± 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 ± 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 ± 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 ± 1.05 kcal/kg0.75 of empty BW (EBW) or 67.4 ± 1.04 kcal/kg0.75 of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/kg0.75 of EBW or 103.0 kcal/kg0.75 of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 ± 0.4 g of net protein/kg0.75 of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations. Copyright © 2007. . Copyright 2007 Journal of Animal ScienceKeywords
This publication has 17 references indexed in Scilit:
- PrefaceSmall Ruminant Research, 2004
- Maintenance energy requirements of goats: predictions based on observations of heat and recovered energySmall Ruminant Research, 2004
- Metabolizable protein requirements for maintenance and gain of growing goatsSmall Ruminant Research, 2004
- Prediction of metabolizable energy and protein requirements for maintenance, gain and fiber growth of Angora goatsSmall Ruminant Research, 2004
- A comparison of nitrogen values obtained utilizing the Kjeldahl nitrogen and Dumas combustion methodologies (Leco CNS 2000) on samples typical of an animal nutrition analytical laboratoryAnimal Feed Science and Technology, 1998
- Energy and Protein Utilization in Growing CattleJournal of Animal Science, 1984
- A System for Expressing Net Energy Requirements and Feed Values for Growing and Finishing Beef CattleJournal of Animal Science, 1968
- The heat of combustion of the urine of sheep and cattle in relation to its chemical composition and to dietBritish Journal of Nutrition, 1966
- Prediction of the amount of methane produced by ruminantsBritish Journal of Nutrition, 1965
- The Heat of Combustion of the Tissues of Cattle in Relation to their Chemical CompositionBritish Journal of Nutrition, 1953