Parity Effects on Milk Somatic Cell Count in Bos indicus: Implications for Sustainable and Productive Dairy Systems

Studies have revealed that primiparous females with high somatic cell counts (SCC) may be predisposed to a shorter productive life. To this end, the effect of calving on milk composition and somatic cell count was assessed. To this end, 150 cows (75 primiparous and 75 multiparous) managed under grazing conditions (Megathyrsus maximus) were evaluated over a period of 21 days. A 50 mL pool was collected aseptically from the four quarters of each cow. The results showed higher milk production in the multiparous group (P = 0.003). However, the primiparous group of cows was characterised by higher protein content (P = 0.01) with a tendency towards lower SCC (P = 0.07). In addition to this, the fat and total solids contents, as well as protein and non-fat solids, were found to be positively correlated (r = 0.79 to 0.92). Despite this, our study did not show a correlation when we analysed production and SCC, which would indicate that volume alone cannot be a reliable indicator of udder health. In conclusion, parity is a very influential factor in both production volume, milk composition and SCC. Consequently, implementing feeding and management strategies are alternatives for reducing the risk of subclinical mastitis, promoting more sustainable milk production. This information would also serve to strengthen mastitis control programmes, optimising the dairy systems of small producers in tropical regions. Keywords: Milk composition; Tropical livestock; Small livestock systems; Pastoral systems; Udder health.