Assessment of genetic parameters and breeding value of somatic cell score and first lactation 305 days milk yield in crossbred dairy cattle of Kerala

Present study focuses on estimating the genetic parameters and breeding values related to somatic cell score (SCS) and first lactation 305 days milk yield (FL305DMY) in crossbred cattle in Kerala. Mastitis, a common inflammatory condition of the mammary gland, poses significant challenges to dairy production by decreasing milk quality and quantity, resulting in considerable economic losses for farmers. The study involved 200 first-lactation crossbred cows from various locations and 200 raw milk samples were analysed for SCS estimation. Overall least square mean of SCS and 305 DMY were 4.85 and 2409.35 kg, respectively. The heritability estimates for SCS and 305 DMY were 0.003±0.340 and 0.359±0.076. The average breeding value of 200 crossbred cattle sired by 78 bulls for SCS was 4.16 and for 305DMY was 2743.60 kg. The negative genetic correlation between SCS and FL305DMY (-0.113 ± 0.38) further emphasizes the detrimental impact of mastitis on milk production. The results indicate the necessity of incorporating SCS into selection criteria for dairy cattle to enhance both milk yield and overall herd health.