Effect of Management and Environmental Factors on Semen Production Potential of Indigenous Cattle Breeds

Background: The production of higher number of quality semen doses from the indigenous bulls is required to mitigate the issue of declining population of indigenous cattle breeds. To make the semen production more efficient, the knowledge of factors affecting the semen production is of utmost importance. However, studies on different indigenous breeds are scarcely available and very little information is available on effect of ejaculate number, collection interval, semen collector etc. The present investigation was hence focused to study the effect of different management and environmental factors affecting semen production traits in indigenous breeds. Methods: Semen data comprising of 15,435 ejaculates from 60 bulls of 10 indigenous cattle breeds were analysed for semen production traits. Prior to the analysis, data on initial motility was transformed using the arcsine transformation. Least square analysis was carried out using "lm" function while ANOVA (Type III sum of square) and Duncan's multiple range test were computed using "car" and "agricolae" packages from R statistical software. Result: The overall means for the semen production traits: ejaculate volume, sperm concentration, total sperm, initial motility and total motile sperm were 5.62 +/- 0.041 ml, 1.42 +/- 0.51x 10(9)/ml, 7.96 +/- 0.25x 10(9)/ejaculate, 74.77 +/- 0.002% and 5.92 +/- 0.11 x 10(9)/ejaculate, respectively. All traits were significantly affected by order of ejaculate, collection interval, age at collection, breed, semen collector, season and year of collection except collection interval which had no effect on motility. Except initial motility, semen characters showed quadratic pattern over the age. Results of the study would help in suggesting suitable management and breeding plans for semen production traits.