Dietary supplementation with nonconventional feeds from the Middle East: Assessing the effects on physicochemical and organoleptic properties of Awassi sheep milk and yogurt

Abstract

Increased feed costs affect the livelihoods of dairy sheep farmers in the Middle East. Farmers endure high risks with large fluctuations in the price of grain used as animal feed, which is further affected by drought and declining range productivity. Using agricultural by-products and treated straw or vetch grazing for supplementing sheep diets would provide resource-poor dairy farmers with increased options to reduce feed costs, but the effects of such feeds on the quality of yogurt (the main product) need to be better understood. Two experiments were conducted to evaluate these effects. The first trial evaluated alternative diets using locally available feedstuffs, including agricultural by-products, compared with traditional diets used by dairy sheep farmers, and was conducted on-station at the International Center for Agricultural Research in Dry Areas (ICARDA, Tel Hadya, Aleppo, Syria). Milking Awassi ewes (n=56) were used to test 6 alternative diets against a traditional control diet containing barley, wheat bran, and barley straw. The 6 alternative diets contained 4 or more of the following ingredients: barley, sugar beet pulp, molasses, cotton seed cake, wheat bran, urea-treated wheat straw, and barley straw. Ewes on one of the alternative diets grazed vetch pasture, whereas ewes on the control diet and the 5 alternative diets grazed native range pasture. The milk fat content was higher in diets containing urea-treated straw. Yogurt firmness and adhesiveness were significantly lower in energy-rich diets (e.g., the control diet) and in the diets rich in soluble sugar (molasses). The effects of diet on yogurt color and on citric and succinic acid contents were significant. A yogurt produced from the milk of the group grazing on vetch was the most yellowish in color, which is appealing to Syrian consumers. The content of citric acid tended to be higher in yogurts produced from diets containing molasses. The second trial was conducted on 3 farms in northern Syria to assess an alternative diet (1 of the 6 tested in the first trial) on 15 milking ewes compared with the farmer's traditional diet (control). The alternative diet increased yogurt firmness and adhesiveness by 7 to 9% and 10 to 16%, respectively. The use of nonconventional feeds available in the region enhances yogurt quality, may reduce requirements for expensive grains, and thus, increase farmers' livelihoods by targeting expanding markets with better quality products.

Evaluation of the bioprotectivity of Lactobacillus binary/ternary cultures in yogurt

“…It is reported that starter culture had a meaningful impact on gumminess and chewiness of yogurt (Penna et al., 2006). Adhesiveness is strongly linked to firmness (Hilali et al., 2011). Mani‐López et al.…”

Obtenção E Caracterização De Iogurte Em Pó De Leite De Ovelha

“…Pode-se verificar que o produto apresentou 83,77 % de umidade e 0,24 % de cinzas, corroborando com os dados obtidos por Mishra e Kumar (2004), que encontraram 81,9 % de umidade e 0,7 % de cinzas no iogurte de leite de ovelha. O teor de lactose foi de 4,59 %, estando próximo aos valores encontrados por Katsiari et al (2001) e Hilali et al (2011), que foram de 4,87 % e 4,84 %, respectivamente, no iogurte de leite de ovelha.…”

Desenvolvimento de Frozen Yogurt de iogurte em pó de leite de ovelha

“…O resultado de acidez encontrado está de acordo com o padrão estabelecido pela IN nº 46, do regulamento técnico de identidade e qualidade de leites fermentados (Brasil, 2007), que é de 0,6 a 2 g/100g. O valor de acidez obtido neste trabalho foi similar aos encontrados por Pinto et al (2012) e Hilali et al (2011), que foram de 1,2g/100g e 1,52g/ 100g, respectivamente, ao final da fermentação em iogurte de leite de ovelha.…”