Effect of ejaculation frequency and management conditions on semen quality, fertility and hatchability of local turkeys in the humid tropics

Thesis Abstract

Two experiments were conducted to determine the effect of frequency of semen collection and management systems on semen quality, fertility and hatchability of local turkeys in the humid tropics. A total of 72 local Nigerian turkeys comprising 24 males and 48 females were used for the study at 36 weeks of age with average body weight of 9kg for the males and 4kg for the females. The males were randomly divided into two groups (1 and 2) with 12 males in each group. Group 1 males were intensively managed and fed 17% crude protein and 12.6 MJ/kg metabolizable energy breeder diet. Group 2 males were semi-intensively managed and subjected to free-range condition and given supplements. The males in both groups were subjected to four frequencies of semen collection (once, twice, three times and four times) weekly using abdominal massage technique. A total number of 286 ejaculates were collected and analyzed for volume, motility, sperm concentration, live sperm, normal sperm, abnormal sperm and total sperm in ejaculate. The forty eight hens were randomly divided into two groups (1 and 2) corresponding to the male groups, with 24 hens in both groups, 6 hens per each ejaculation frequency. The hens were sexually stimulated by ‘venting’ and inseminated with 0.25ml of semen weekly during late afternoon. A total number of 729 eggs were incubated and analyzed for fertility and hatchability. The results showed that ejaculation frequency had significant (P < 0.05) effect on all the semen quality parameters measured. Two times per week semen collection yielded the highest ejaculate volume, sperm motility and normal sperm in both management groups compared to other ejaculation frequencies in both intensive and semi-intensive management systems respectively. The semi-intensively managed toms had higher (P<0.05) mean values for motility, and live sperm. Sperm concentration values were similar among intensively and semi-intensively managed toms at all ejaculation frequencies. Abnormal sperm values were significantly (P< 0.05) highest in both groups under once per week ejaculation frequency and lowest in toms ejaculated twice per week. Increasing frequency of semen collection above twice per week decreased semen volume, sperm concentration and total sperm in ejaculate. Increasing frequency of semen collection increased progressive motility percentage live sperm and abnormal sperm. There was no significant interaction (P > 0.05) effect between management system and ejaculation frequency on all semen quality, parameters measured. Fertility and hatchability results indicated significant (P <0.05) effect of ejaculation frequency on all parameters measured. Percentage fertility ranged from 71.01 ± 2.65% to 92.18 ± 21.18. Out of a total number of 729 eggs incubated, 614 eggs were fertile. Percentage hatchability results obtained in this study ranged from 85.11 ± 4.20% to 100.00 ±0.00% in both management systems. There was no significant interaction (P > 0.05) between management systems and frequency of semen collection on fertility and hatchability of local turkey eggs. It was concluded that two times per week collection frequency was ideal for local toms used for AI programmes while toms to be used can perform well in the programme under both management systems.