Effect of Lambing Season and Production Stage in Some Milk Traits and Udder Health State in Awassi Ewes

Abstract

This study was conducted on 10 Awassi ewes (3 -4 aged) lambed in winter season ( January) and another 10 ewes lambed in spring season (March) to determine the effect of season and stage of lactation on daily milk yield, milk components and udder health state, ewes reared on concentrate ration (1.5 kg DM/ ewes) in addition to grazing 3 hrs. daily. Milk samples were collected at the end of 2nd ,6th ,10th and 14th week after lambing (which represent the stage 1, 2, 3 and 4) and examined to measure milk components and somatic cell counts (SSC). Results showed a significant (P ≤ 0.05) increase in daily milk yield (DMY), fat ( F ), protein (P) and solid nonfat components (SNF) % in spring season , also a significant increase in DMY at 1st , F% and P% at 4th and SNF% at 3rd stage of milking period. The results also showed that the highest interaction effect on DMY and F% at 1st stage, P% at 2nd and 4th stages and SNF% at 3rd stage in spring season, also SSC significantly (P ≤ 0.05) increased with 3 and 2 subclinical infection of mastitis in winter and spring respectively, SCC increased significantly at 4th stage with 2 and 3 infection at 3rd and 4th respectively, also the highest interaction of SCC was at 4th stage in winter. There is a significant negative correlation between DMY and milk components excepting lactose% in two seasons and positive correlation between F, P, SNF and SCC, and between SNF and SCC. In general this study revealed that a higher DMY recorded at 1st stage in spring season, some of milk components increased with the increase of SCC.