Relationship of testicular development with age, body weight, semen characteristics and testosterone in Kivircik ram lambs

Abstract

The study was conducted to measure the development of several testicular characteristics and to investigate the relationship between testicular parameters with body growth, semen characteristics and serum testosterone levels in growing ram lambs. Seventeen single born Kivircik ram lambs from three to four year old ewes were used. When the rams were two months old measurements of the length, diameter and circumference of their testes and body weights started, and blood samples were collected at 20-day intervals for the next 12 months. From seven to 14 months of age semen was collected at monthly intervals. There was a gradual and linear increase in testicular dimensions from two to 11 months of age. A rapid increase in all testicular dimensions was observed between 140 to 160 days of age. All measurements of testes, live weight, age and serum testosterone concentrations were positively and significantly correlated with each other. While a significant positive correlation was found at seven and eight months of age between all testicular measurements and semen volume and motility, no such correlations were observed between nine and 14 months of age. From seven to 14 months of age no correlation was measured between serum testosterone concentrations and spermatological characteristics. These results demonstrated that testicular measurements, especially scrotal circumference, can be used as criteria for early selection of ram lambs to be used in breeding at relatively young ages.

Biometric Indicators, Testicular Parameters and Semen Characteristics in Peripubertal and Postpubertal Pleven Blackhead Rams

“…Ultrasound examination for interpreting uncertain clinical findings or for detecting early stages of pathological processes in ram genitalia is very important for the complete reproductive assessment (Gouletsou et al, 2003;Gouletsou and Fthenakis, 2010;Ahmadi et al, 2013;Saaed and Zaid, 2018). The mean values of scrotal circumference in both categories rams (18.8 ± 5.9 cm and 30.7 ± 4.4 cm) were close to values for young Synthetic Population Bulgarian Milk rams (23.7 ± 0.4 cm) and mature Kivircik animals (30.24 ± 0.91 cm), reported by Elmaz et al (2007) and Metodiev et al (2014), respectively. However, no correspondence was observed with the results (29.23 ± 3.32 cm and 33.23 ± 1.60 cm) in pubertal and sexually mature Santa Ines rams (Ribeiro et al, 2017) or the records (31.8 ± 0.4 cm and 33.3 ± 0.5 cm) for peri-and postpubertal Dorper rams (Camela et al, 2019).…”

“…An evidence for this suggestion was no collected semen from two younger animals in the first group by electroejaculation method. The positive correlation between VE and CS may be related to better hormonal stimulation of the sperm producing tissue and development of the accessory glands in sexually mature animals (Elmaz et al, 2007;Ribeiro et al, 2017).…”

Effect of milk replacer and rumen inert fat on growth and reproduction of Malpura ram lambs

“…Testicular dimension and size of the ram lamb can be used as criteria for early selection of ram lambs to be used in breeding at relatively younger age (Elmaz et al, 2007). Moreover, reproductive activity of rams is dependent and significantly correlated with postweaning growth and size of the testes (Elmaz et al, 2008).…”

Effects of different hay: concentrate ratios on body and testicular-epididymal biometry and metabolic profile of Santa Ines lambs

“…Early studies showed that there are significant positive correlations between testicle measurements and seminal traits in young seven to eight month old rams (ELMAZ et al, 2007). So, this information may be used as criteria for early selection of ram lambs to be used in breeding at relatively young ages (ELMAZ et al, 2007).…”

“…These body measurements have been used at various times for the estimation of weight (YILMAZ et al, 2013), breed characterization and differentiation (YAKUBU;IBRAHIM, 2011), and for early selection of ram lambs (ELMAZ et al, 2007). As regards testicular-epididymal biometry, some studies have demonstrated that body weight may be reflected in testicle size (DUGUMA et al, 2002), because the heritability between scrotal circumference and testis diameter is moderate to high.…”