A Phenotypic and Genetic Study of Semen Production and Semen Quality Traits Among Young and Adult Cattle Bulls in India

Abstract

Semen characteristics of 97,112 ejaculates from 399 adult bulls of 2 exotic breeds, 2 indigenous breeds and crossbred sub-populations with 50% and 75% of exotic inheritance, and of 3,293 ejaculates from 292 test bulls were analysed. The traits considered were: ejaculate volume, sperm concentration, total number of sperms, initial and post-thaw motility, and a theoretical number of doses produced from each given ejaculate. The objective was to measure the semen production potential of different genetic groups of cattle breeds, to identify factors affecting semen production and quality traits, and to assess the correlation between semen characteristics measure on test and adult bulls. A linear mixed model was used to evaluate the effect of different fixed and random effects. For adult bulls, the first ejaculate of a bull on a particular day and longer collection intervals lead to better characteristics for all the parameters but short collection interval with two ejaculate on particular day lead to a larger number of total semen doses produced without hampering semen quality. Repeatability estimates for semen traits were found to be low to moderate. Low to moderate and negative bull correlation was observed between concentration and volume in all the breed groups while the correlations of bull effects of the two motility traits were comparatively large. The moderate to high correlation for all semen traits between their testing and when they are adult highlights the importance of andrology evaluation in predicting future semen production of AI bulls in order to discard the less productive bulls.

Effect of Guava Filtrate Supplementation in Tris and Citrate-Based Extenders on Spermatozoa Quality of Brangus Bull after Sex-rest

“…Table 1 shows that, the volume of semen obtained was lower than that reported by some previous researchers, namely 5.48 to 6.44 ml (Bhave et al, 2022), 5.20 ± 0.08 ml with variation from 5.12 ± 0.15 to 5.98 ± 0.09 among the ages 3 -9 years (Sankhi et al, 2019), 4.84 ± 0.01 ml in Kankrej bulls semen (Patel and Siddiquee, 2013), and 10.5 ml (Hossain et al, 2012). This difference was presumably caused by the sexual break of Brangus bulls for several years, and poor quality of the woof.…”