A study on testicular characteristics of ram lambs of Arsi breed fed on two maize varieties (QPM and BH540)
The effect of feeding two maize (Zea mays) varieties (Quality Protein Maize [QPM] and common maize [BH540]) on testicular characteristics of ram lambs was studied in the indigenous Arsi sheep breed. The two maize varieties were fed in whole plant silage (WPS), earless silage (ELS) and stover (S) forms for a period of 12 weeks. Variables measured during the feeding trial were scrotal circumference, testicular diameter and scrotal skin thickness in live ram lambs and testicular length, width, height and epididymis weight after slaughtering. There were no conclusive findings with regard to differences between the two maize varieties (QPM and BH540) in supporting growth rates of testicular traits, yet the offer types (WPS, ELS and S) did appear to have an effect. Ram lambs fed on whole plant silage had shown the highest (P< 0.001) scrotal circumference (28.1±0.3cm), scrotal circumference gain (0.45±0.03 mm/head/day), testicular diameter (5.77±0.09cm) and testicular diameter gain (0.13±0.01 mm/head/day) compared to the maize stover and earless silage fed groups. Testicular traits were positively and significantly correlated with each other (r = 0.73 to 0.95; P< 0.001). The results suggest that the plane of nutrition influences testicular size. Whole plant silage feeding provided improved testicular size. Therefore, maize whole plant silage feeding might be helpful to improve the productive and reproductive performance of ram lambs.