Genetic and non-genetic factors affecting semen production traits in Karan Fries crossbred bulls

Abstract

The objective of the study was to evaluate the effects of genetic and non-genetic factors on production of breeding bulls and semen quality parameters in Karan Fries crossbred male by fitting least squares analysis. Genetically, the animals were divided into three subclasses. The non-genetic factors were season of birth, period of birth, and age group with three subclasses each for season of birth and period of birth. Age group was classified into four subclasses. The traits generated in the study were number of males reaching semen donation stage (AFSC) and first freezing (AFSF), age at last semen collection (ALSC) and last freezing (ALSF), age at disposal (AD), and lifetime semen production traits (up to 1 year after first freezing). The effect of period of birth was significant for AFSC, AFSF, ALSC, and AD. It was also significant for total ejaculates produced in a year. The age group had significant effect on AFSF. Effect of genetic group was significant for freezable ejaculates produced in a year, for frozen semen doses produced in a year, and for number of ejaculates cryoprocessed in a year. Season had no statistically significant effect on any of the traits studied. The influence of period revealed that the most of the traits of breeding bulls improved after intermediate period, which could be due to better care, training, feeding, and other management practices in the latter years. However, no consistent trend could be established for the effects of genetic groups and other non-genetic causes on the traits considered.

Divergent development of testosterone secretion in male zebu (Bos indicus) and crossbred cattle (Bos indicus x Bos taurus) and buffaloes (Bubalus bubalis) during growth

“…4). One of the most important reasons for poor semen quality in crossbred bulls (Khate 2005;Chauhan 2007) may be low testosterone production in these animals as observed in the present study in crossbred males.…”

“…However, the male crossbred offsprings are often inferior to purebreds in semen production. The proportion of males reserved for breeding and reaching successful freezing stage was lowest (29%) in Karan Fries (cross between Sahiwal or Tharparkar with Holstein Freisian cattle) and highest (45%) in Sahiwal cattle and poor semen quality was an important reason of disposal in Karan Fries bulls (Khate 2005;Chauhan 2007). Poor semen quality was found to be the main reason of disposal in adult breeding Karan Fries bulls above 3 years of age (Chauhan 2007).…”

Effect of Non-genetic Factors on Culling and Mortality Rate in Murrah Buffalo Males

“…Disposal due to surplus was observed in these age groups which might be due to more number of bulls available than the requirement of the farm. At NDRI herd Chauhan (2007) conducted a study on Karan Fries males and found that important cause of disposal for male calves below 1.5 years of age was mortality and in case of above 1.5 years of age group, culling due to poor growth and poor semen quality were the main reasons. Based on 15 yrs data Mukhopadhyay et al (2010) reported that subfertility problem is one of the major causes of disposal of breeding bulls which was almost one-third to half of the reserved stock disposed due to sub-optimal reproduction efficiency and poor libido was one of the important cause of subfertility among the Murrah buffalo males.…”

Culling pattern of Karan Fries (crossbred) males in an organised herd

“…Lal (1991) reported that morphology of calves and its dam's performance were considered as selection criteria in young bulls but later on when the animal matures, its semen characteristics like volume, colour, concentration, motility, live/death count and semen freezability were considered. Although a large number of male animals are reserved and raised for semen donation, more than half of those animals are disposed or rejected before reaching frozen semen production stage due to various reasons like offbred, disease, poor growth and health, death, abscess, wound and defective legs (Khate 2005;Chauhan 2007). Young breeding bulls are also culled on the basis of poor libido, poor semen quality and freezability (Chenoweth et al, 2003).…”