Granadina kid goats v. Segureña lambs: food intake and performance during milk feeding from birth to 60 days

Abstract

The morphological development of the sheep and the goat is different and this difference is manifested from early post-natal life. The main characteristic of kid goat carcasses is their low adipose tissue, and this is considered detrimental to quality. In an attempt to determine the nutritional causes of this, a study was performed with kid goats of the Granadina breed and lambs of the Segureña breed. Six kid goats and six lambs were slaughtered at birth, while a further eight kids and eight lambs were fed a milk replacer to satiety until the 60th day of life and slaughtered on the 61st day. Dry matter (DM) and metabolizable energy (ME) intakes and apparent digestibility of energy were determined in four balance periods between 8 and 60 days of life. From the intakes of ME and comparative slaughter data it was possible to calculate energy retention (ER), heat loss (HL) and energy retained as protein (ERp) and as fat (ERf) for kids and lambs. Kid goats showed a similar apparent digestibility of energy to lambs but had lower DM and ME intakes per kg metabolic body weight (M^0·75) than lambs. For kids and lambs respectively these values were: 0·93 and 0·94; 45·4 and 50·1 g/kg M^0·75 per day; 937 and 1033 kJ/kg M^0·75 per day. Mean values for ER, HL, ERp and ERf rates were: 263, 674, 131 and 132 kJ/kg M^0·75 per day for kid goats and, 343, 690, 132 and 211 kJ/kg M^0·75 per day for lambs. Together with the different intake, kid goats showed a lower rate of ER and overall, a lower rate of ERf than lambs.