Milk production, composition and variation at different lactation stages of four goat breeds in Ethiopia

This study was conducted in Ethiopia on four goat breeds: Arsi-Bale, Somali, Toggenburg-Arsi-Bale cross and Boer to assess milk yield and composition at different lactation stages, for the suitability of the milk for cheese production. Milk yield was measured once per week and milk samples were collected three times during the lactation period. Total solids, fat, protein, casein, whey-protein, non-protein nitrogen (NPN), lactose and minerals, (calcium, phosphorus, magnesium, potassium, sodium, zinc and iron) were analyzed. A higher daily milk yield, 1.41 kg, was recorded for Boer goats (P < 0.05), compared to 1.13, 0.93 and 0.85 kg produced by Arsi-Bale, Cross and Somali goats, respectively. Milk from Cross was lower in total solids 13.9% and fat 3.7% (P < 0.001), than Arsi-Bale, Boer and Somali which had 16.3, 15.4 and 14.5% total solids and 5.2, 4.7 and 4.9% fat, respectively. Arsi-Bale goats had significantly higher protein content, 4.8% (P < 0.001) than the rest of the breeds. Lactose content of milk was high in all goat breeds, 4.9% with no significant difference between them. Early and late lactation milk had significantly higher contents (P < 0.001) of milk components. Milk from all breeds was high in calcium, phosphorous and potassium: 1.62, 1.39 and 1.69 g kg(-1), respectively and Fe and Zn: 5.47 and 0.36 mg kg(-1), respectively. Superior chemical composition revealed the potential of milk from indigenous Ethiopian goats for cheese production. (C) 2011 Elsevier B.V. All rights reserved.