The Effect of Non-genetic Factors on the variation in milk components of Awassi sheep under Semi-Intensive care conditions

Abstract

For this study, (154) heads of Awassi ewes were used during (3) years (2020 ,2019, 2021) located in Hama Research Center of the General Authority for Scientific Agricultural Research, with the aim of investigating the changes in the components of Awassi sheep milk during the milking season under the influence of some non- genetic factors under semi-intensive care conditions. Milk samples were analyzed by Lactoscan device, and the data were analyzed statistically by using the Least Square Mean method according to the SPSS program. The results showed that the general average of the percentages of fat, protein, lactose and solid non-fat material was (6.4 ± 0.072%, 4.3 ± 0.012%, 4.1 ± 0.014%, 9.0% ± 0.031), respectively. There was a significant effect(P<0.05) of the order of the season of birth and the month of milking in the proportions of the milk components, while there was a non-significant effect of the year of birth, the birth model, the sex of the newborn and the month of birth in the proportions of those components. A significant effect(P<0.05) of the milking stage, the milking season and the age at birth on the percentage of fat was also observed, however it was not significant on the percentages of protein, lactose and non-fat solids. It was found that there was a significant (P<0.05)effect of the mother's weight at birth on the percentages of both fat and lactose, and insignificant in the percentages of both protein and non-fat solids. The highest significant value of the phenotypic correlation was recorded between protein and between non-fat solids and lactose (+0.811, +0.383) respectively, andnegative between fat and between total milk production and protein (-0.038, -0.495), respectively. The correlation was negative between milk production and its components.