Composition and Nitrogen Distribution of Ouled-Djellal and Rumbi Algerian Ewe's Milk

B Yabrir,A Mati,H Attia,A Laoun,M Labiad,A.Hakem (Ex Akam)

doi:10.19026/ajfst.5.3086

Abstract

The chemical composition and nitrogen distribution of milk from two ewe's breed (Ouled-Djellal and Rumbi) (n = 20 each) reared in Algerian area steppe, were studied. The ewes were balanced for age and weight. All were in middle period of lactation. Individual milk samples were taken from each ewe third time from lactating period during spring season. Rumbi ewe's milk gave the highest values (p≤0.01) for lactose (4.89±0.61%), solid non-fat (11.19±0.87%) and density (1037.57±3.78) than Ouled-Djellal ewes (4.38±0.45%, 10.24±0.77% 1033.82±2.59, respectively) and lowest values (p≤0.01) for freezing point (-0.57±0.05°C vs -0.53±0.02°C). No significant difference was observed between the two breeds on fat, protein, total solids. The mean percentages were 6.26±1.38%, 5.54±0.76 and 16.51±1.44%, respectively for Ouled-Djellal ewes, while those of Rumbi's were 5.66±3.52%, 5.91±1.10% and 16.85±3.32%, respectively. No statistical differences related to the breed were found in the milk for all nitrogen fractions. Rumbi ewe's milk contains about 1.01% nitrogen however Ouled-Djellal's hold about 0.96%. Total nitrogen content is distributed between non-protein nitrogen (0.09% in all breeds) and protein nitrogen (0.93 vs 0.87% for Rumbi and Ouled -Djellal ewes respectively). The protein nitrogen includes casein nitrogen (0.76 vs 0.71) and whey protein nitrogen (0.20 vs 0.19%) from Rumbi and Ouled-Djellal ewes, respectively. Algerian sheep breeds were not actually selected for their milk production; selection program should be implemented to improve milk production and increase fat and protein contents. Thus further studies should carry out on milk ability and milk yield of these breeds.

Highlights

The population of sheep in Algeria is estimated at over 21 million heads (ONS, 2009)
Solid non-fat, freezing point and density were significantly influenced by breed type
The present study shows that the NT content is distributed between non-protein nitrogen (NPN, 0.09% in all breeds) and Protein Nitrogen (PN, 0.93 vs 0.87% for Rumbi and Ouled-Djellal ewes respectively, with average equal to 0.90%)

Summary

Introduction

The population of sheep in Algeria is estimated at over 21 million heads (ONS, 2009). Ouled-Djellal (OD) is the most common breed and represents approximately 63% of the total number, comes Hamra with a percentage of 21%; the Rumbi (RB) represents 12% of the total population (Boucif et al, 2007). Average milk production per day, all races confounded, is estimated at 400 g for 4 to 5 months (Khelifi, 1999). This production is valued at 70-80 kg in 6 months of lactation for OD ewes; it is 55-65 kg in 5-6 months for Rumbi’s (Chellig, 1992). This milk is generally used for breast lambs in the first place, it is consumed by the farmers as well as or transformed traditionally often on “smen” (traditional butter), on “l’ben” (fermented milk) or in “djeben” (fresh cheese)

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Conclusion