Seasonal Variations in Semen Parameters of Zulu Rams Preserved at 10°C for 72 H During Breeding and Non-Breeding Season

Abstract

The study was conducted to evaluate the seasonal variations in semen parameters of Zulu rams preserved at 10°C for 72 h. The study site was the Agricultural Research Council (ARC) Irene, during the breeding season and the non-breeding season. Zulu rams (n = 6, age = 3 years and average weight = 35 kg ±2.29) were used in this study. Semen was collected with the aid of artificial vagina. Macroscopic (volume and pH), microscopic (sperm concentration, progressions, velocities and velocity ratios and morphology) semen parameters were evaluated immediately after semen collection. Data were analyzed using General Linear Model (GLM) in Minitab 17®. Semen volume was higher during breeding season (0.97±0.25 mL) than non-breeding season (0.72±0.5 mL). Total sperm motility was higher (92.01±1.40%) at 24h during breeding season than non-breeding season (88.69±1.40%), thereafter declined drastically in both seasons. However, non-breeding season yielded a high progressive motility (50.86±1.63%, 33.77±1.63% and 27.56±1.63%) after 24, 48 and 72 h than breeding season (21.32±1.63%, 11.89±1.63% and 10.29±1.63%). It was concluded that, semen parameters from Zulu rams does vary with seasons. Nevertheless, despite seasonal variations observed, Zulu rams' semen quality is acceptable in both breeding and non-breeding season hence can breed throughout the year. Notwithstanding, studies involving fertility are recommended and the nutrition effect of lambing during dry period should be considered.

An Update on South African Indigenous Sheep Breeds’ Extinction Status and Difficulties during Conservation Attempts: A Review

“…Zulu sheep, on the other hand, have been characterized phenotypically [12]. In our best information, there are numerous studies on Zulu sheep, such as morphological structure [12], morphological differentiation [3], semen quality in different ages [34], and seasons [37].…”

“…Semen characteristic: Semen has been characterized in South African indigenous rams (Table 10). There are numerous studies conducted to evaluate semen characteristics of South African indigenous rams [36,37,45,47].…”

Seasonal Variations in Semen Quality, Testosterone Levels, and Scrotal Size following Dietary Flaxseed Oil and Ascorbic Acid in South African Indigenous Rams

“…Fortunately, poor flock reproductive performance in ewes associated with the season can be mimicked using exogenous hormones to program lambing at a favorable season of the year, where pastures or veld are greener, in order to reduce mortality rates [ 19 ]. However, seasonal manifestation in rams is not well understood because some breeds show little or no seasonal effect [ 20 , 21 , 22 ]. Despite the seasonal effects, nutrition is another factor affecting semen production, spermatogenic tissues, testicular interstitial tissues, and the sexual behavior of rams [ 23 ].…”

Seasonal changes in testis size, testosterone levels and sperm production quality in meat rams

“…Semen quality and quantity as indicators of reproductive efficiency in male rams are influenced by factors such as breed, season of the year, frequency of ejaculation and breeding methods (Greyling and Grobbelaar, 1983). Ngcobo et al (2020) indicate that the sperm parameters of Zulu rams depend on the season, while in the breeding season, the quality of sperm is better than in the off‐season of reproduction.…”