Effect of feeding treatments and lactation stages on composition and organoleptic quality of goat milk Domiati cheese

Abstract

To investigate the effect of pasture feeding with different levels of concentrate on the milk composition and quality of Domiati cheese, a total of 20 lactating Alpine goats were randomly allocated into four groups. Group A was confined and fed alfalfa hay with 0.66 kg per day of concentrate mixture per 1.5 kg of milk (conventional confinement system with feeding). Groups B, C, and D were rotationally grazed and received 0.66, 0.33, and 0 kg per day of concentrate, respectively. Milk from each group was processed into Domiati cheese twice monthly for a 6-month lactation period. Cheeses were sampled fresh and at 1 and 2 months of pickling in whey. Results of the present study indicate that feeding systems of dairy goats with different levels of concentrate supplementation did not affect the composition (fat, protein and total solids) of Domiati cheese. The pasture-grazing without concentrate supplementation (group D) resulted in a lower short-chain fatty acids content and a higher flavor score of Domiati cheese than the confined feeding system (group A). Cheese age during pickling did not change flavor score but increased the total sensory score due to a smoother, creamier body and texture of cheese. As lactation advanced, the contents of total, short- and long-chain fatty acids and the sensory scores of the cheese fluctuated markedly. Further research is needed to investigate the effect of fatty acids in diets on the profile of fatty acids in goat milk and cheese, and to correlate the individual fatty acids in diet, milk and cheese to establish the sensory quality of goat cheese.