Subfertility in Males: An Important Cause of Bull Disposal in Bovines

Abstract

The study had two objectives, namely, to estimate the andrological disorders leading to disposal of Karan Fries (KF), Sahiwal cattle and Murrah buffalo bulls and to study the effect of various factors (species/breeds, season of birth and period of birth) on male reproductive parameters. Records on occurrence of subfertility problems and disposal pattern of bulls maintained at the National Dairy Research Institute herd were collected for 15 years (1991 to 2005). Percentage of bulls producing freezable semen was less in the crossbred cattle (58.46%) as compared to Sahiwal (81.69%) and Murrah bulls (81.05%). Various subfertility traits like poor libido and unacceptable seminal profile were found to be the significant reasons (p<0.01) for culling of the breeding bulls. Inadequate sex drive was the main contributing factor for bull disposal in Sahiwal (22.55%) and Murrah bulls (15.12%) whereas poor semen quality and freezability were most frequently observed in KF bulls (24.29 and 7.29 percent, respectively). Least squares analyses of different male reproductive parameters showed that species/breeds had significant effect (p<0.05) on all traits except for frozen semen production periods (FSPP). Periods of birth were significantly different (p<0.05) for all traits except for semen volume. Age at first semen collection (AFSC), age at first semen freezing (AFSF) and age at disposal (AD) were highest in Murrah, while frozen semen production period (FSPP) and semen production period (SPP) were highest in KF and lowest in Sahiwal. The age at first semen donation and breeding period could be reduced by introducing the bulls to training at an early age. These results revealed a declining trend in AFSC, AFSF, FSPP, SPP and AD, thereby indicating an improvement in reproductive performance over the years. The age at first semen donation in bovines can be reduced by introducing the young male calves to training at an early age, which could increase the dosage of semen obtained from each male.

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

“…Among the reserved breeding bulls, disposal due to poor libido was 7.53% which were comparable with the finding of Khate (2005). Lower percentage of culling in crossbreds bulls due to poor libido was also reported by Mathew et al (1982); Mukhopadhyay et al (2010) and Khatun et al (2013). Poor semen freezability (4.45%) in our present study was lower than the finding of Mathew et al (1982); Suryaprakasam and Rao (1993); Sudheer and Xavier (2000) and Mukhopadhyay et al (2010) in CB bulls.…”

“…The major reason of culling was poor semen quality (10.27%) in KF bulls. Our present findings were lower than that reported by Rao et al (1995); Sudheer and Xavier (2000); Khate (2005) and Mukhopadhyay et al (2010) in crossbred bulls. Among the reserved breeding bulls, disposal due to poor libido was 7.53% which were comparable with the finding of Khate (2005).…”

Luteinizing hormone, testosterone and total estrogens response to exogenous GnRH in crossbred bulls with differing semen quality

“…However, the percent production of freezable semen of the crossbred Karan Fries (KF) bulls (58.46%) was inferior to that of the purebred Sahiwal bulls (81.69%) (Mukhopadhyay et al, 2010). Studies have reported that impaired semen production capacity, poor libido, and low freezability are the major reasons for the rejection of the semen of crossbred bulls in the semen collection stations (Sethi et al, 1989;Sahni and Mohan, 1998).…”

Effect of age and season on semen quality parameters in Sahiwal bulls

“…In a breeding farm, extent of variations of semen quality over a long period may depend on existing macro-and micro-climatic conditions, feeding and general management, besides the sexual activity of the animal influenced by surrounding environment during semen collection (Mandal et al 2000). Semen quality is affected by breed (Mukhopadhyay et al 2010); reproductive health status of bulls, technical skills, age (Mandal et al 2010;Ahmad et al 2011), and genetic constitution of bull (Koivisto et al 2009) over a long period may not be consistent as it is not under a single managemental hand.…”