Quality and fatty acid profile of milk of indigenous dairy goats fed from oasis resources in Tunisian arid areas

Abstract

Context The food security of Tunisia is dependent on utilising all of its resources effectively to feed the population. Rangelands used for grazing are subject to continuous degradation, which reduces the availability of feeds to livestock. In the oasis regions, this constraint is attenuated by the systematic use of various by-products of the palm grove. There is a need to constantly search for alternative feed resources to support ruminant-livestock farming in arid regions and, therefore, the products of desert oases need to be exploited Aims The present work aimed to determine the effect of the use of local resources of oases on feed intake and milk quality of goats. Methods Twenty-four indigenous lactating goats were used to investigate the effect of the substitution of the concentrate feed with alternative feed obtained from oases in Tunisian arid zones. The three study groups in the 60-day trial were as follows: the first group received 0% date waste (WD) + 100% concentrate (CON) + oaten hay; the second group received 50% WD + 30% alfalfa cork (AC) + 20% CON + alfalfa hay; and the third group received 50% WD + 50% AC and no CON + alfalfa hay. Key results Feed intake was higher in Group 2 (1167.10 ± 42.8 g DM/day) than in Groups 3 and 1 (1028.9 ± 68.9 and 856.04 ± 58.9 g DM/day respectively. Average daily milk production did not differ among the groups. Dietary fat and crude protein were not affected by the type of ration. The concentrations of saturated fatty acids were similar in the milk of the three groups. In the three groups studied, the ratio n6:n3 (12.80, 8.80 and 6.77) was higher than the recommended value (<5) for human consumption. Conclusions The use of WD did not affect milk production but it improved the nutritional quality of milk, especially the composition of fatty acid (ratio n6/n3). Implications The use of alternative resources in goat feeding, such as WD and alfalfa cork, can replace the use of market feeds and decrease the costs of animal feed.