Impact of Management Factors on Seminal Attributes and Frozen Semen Doses Production in Holstein Friesian Crossbred Dairy Bulls

Abstract

This study reports on important management factors that have impacts on semen characteristics, sperm production ability and cryo-preservability in dairy bulls. Except volume, bull types (FSD i.e. frozen semen dose producer vs Non-FSD bulls) differentiated most of the semen traits (P < 0.01). Age showed significant impacts on seminal attributes both in FSD and Non-FSD bulls. In FSD bulls semen traits increased significantly even up to 5 years age, in contrast, only 2 years in Non-FSD bulls. Overall semen quality index improved almost linearly with age advancement in FSD bulls (P < 0.01) but not in Non-FSD bulls, which showed very irrational trends. Seasons significantly (P < 0.01) influenced ejaculate characteristics. Overall semen quality, total sperm output and FSD production was the highest during summer and lowest in rainy seasons. Within a bull type (FSD/non-FSD) influence of age and season, and within age group impact of seasons was significant in most of the semen attributes. It was concluded that dependent on season, age of bull significantly influenced qualitative and quantitative attributes of semen; improvement being substantial in FSD bulls, but negligible in non-FSD bulls beyond 2 years age. Seasons of collection significantly influenced semen quality, sperm productivity and FSD production of bulls being highest in summer, followed by winter and least in rainy seasons. The study recommended that for effective FSD production, poor semen producer bulls should be culled as early as 2 years of age and during rainy season stress amelioration measures might mitigate FSD production losses from crossbred bulls.