Effect of parturition time and climatic conditions on milk productivity, milk quality and udder morphometry in Saanen goats in a semi-intensive system.

Abstract

This study is the first report to investigate the relationships between time of parturition and milk productivity and quality, as well as indices related to udder measurements and meteorological variables, in Saanen goats raised under semi-intensive conditions. Goats giving birth in the hours of darkness had higher milk production than those that gave birth in the hours of daylight, while those giving birth during the evening hours had lower somatic cell count (SCC) than those with parturition during the daylight and night hours (P < 0.05). In addition, the time of parturition was associated with rear udder depth, udder circumference, and udder volume traits (P < 0.01). Parity and time of parturition × parity interaction had significant effects on lactation milk yield and lactation length, as well as milk fat, protein, lactose, total solids content and electrical conductivity (P < 0.05 to P < 0.01). The lactation stage, daily milk yield level and parity affected milk SCC (P < 0.05). Ambient temperature and daylight length had strong effects on daily milk yield (P < 0.05). These findings have practical implications for productivity, quality and health promotion efforts aimed at increasing Saanen goat dairy productivity consistently in the face of climatic changes in a semi-intensive system.