Age‐related changes in semen quality characteristics and expectations of reproductive longevity in Duroc boars

Abstract

Quadratic fitting was used to regress semen characteristics of 1441 samples consisting of 12-month collection from 58 Duroc boars against animal age varied from 10 to 80 months. Data was divided into two groups of cool (14.0-22.7 degrees C, RH 81.5%) and hot season (22.9-29.9 degrees C, RH 86.6%), to test effects of age, season and their interactions. Results revealed that young boars of around 1 year old could endure the hot season. The endurance gradually diminished as animals grew. In the hot season animals exhibited peak performance at age around 33 month and it remained for 1 month, while cool-season kept boars could last for 48 months from 16 months old onward. The reproductive longevity should be 51 month in a subtropical environment and it may extend to 70 month if heat stress can be avoided. The estimated total sperm contribution of a Duroc boar would be 1.8 times more when kept below 22 degrees C than in a natural subtropical environment. It is concluded that to maintain Duroc boars as semen donor to at least 4 years of age is feasible in a subtropical environment and boar longevity could reach 6 years old if well kept in a temperate region.

Production and Quality of Semen in Boars in Insemination Centre

“…In the category of 13 -24 months, there was a sharp increase in the number of spermatozoa, the total number of spermatozoa was 105.83 bn and the corrected number of spermatozoa 70.14 bn, which is in correspondence with the conclusions of the authors Huang et al (2010) and Youngquist and Threlfall (2007), who reported in their works, that semen of 18-month old boars contained more spermatozoa than in younger boars. At the age of 25 -36 months, the total number of spermatozoa and the corrected number of spermatozoa reached similar levels as in the previous categories, exactly 107.42 bn in the case of the total number of spermatozoa and 69.58 bn in the case of corrected number of spermatozoa.…”

“…With age, certain hormonal and cellular changes appear in boars (Huang et al, 2010). There is an assumption that these changes affect the quality and fertilization ability of semen.…”

Effects of season on boar semen parameters and antioxidant enzymes in the south subtropical region in Brazil

“…The effects of season on boar ejaculates are still controversial among authors despite the marked seasonal oscillations in serum hormones and testicular size (Trudeau & Sanford, ). Annual variations alter sperm parameters, such as sperm motility and morphology (Barranco et al., ; Murase et al., ), as well as sperm concentration and total sperm number (Ciereszko, Ottobre, & Glogowski, ; Huang, Lo, Liu, & Yang, ; Zasiadczyk et al., ). However, in the present study, sperm concentration was the only parameter in fresh ejaculates that differed among seasons, although no effect on total sperm number per ejaculate was observed.…”

Age-related changes in quality and fertility of porcine semen

“…Replacement rates are variable, but generally boars are replaced about their third birthday unless they are truly exceptional, in which case they are kept up to 5 years of age. Huang et al (2010) demonstrated that Duroc breed boars could be used as semen donors at least until the age of 4 years, but their reproductive longevity could be extended up to 6 years old if they were kept strictly in a temperature lower than 22 °C.…”