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.
CHAPTER ONE
1.0
INTRODUCTION
1.1 Background
of the Study
Food
insecurity which is felt in most developing nations including Nigeria over the
years has accentuated the already critical animal protein deficiency among
human populations. High cost of livestock and poultry has limited the capacity
of an average Nigerian to consume adequate quantity and quality of animal
protein (Hamzat et al., 2003). Emeruwah
(1999), and Ojewola, et al. (2004) prescribed
massive production of animals with short reproduction cycles such as pigs,
rabbits and poultry as the only remedy to the acute animal protein shortage in
Nigeria. This however, has undoubtedly spurred research efforts in the
direction of these animals that offer the highest turn-over rate and the
quickest return on investment. Obviously, rabbit meat is not popular in Nigeria
and its commercialization is limited by unknown factors. Pigs on the other hand
suffer religious alienation. Thus, poultry has been the animal of choice (Sanni
and Ogundipe, 2003). Although, production of local chicken is evident, large
scale, medium scale and the back-yard poultry production enterprises are
gaining ground in Nigeria as producers now mostly rear more productive exotic
broiler and layer types of chicken which have shown considerable levels of
adaptation to the prevailing environmental conditions.
Okpeku, et al.
(2003) noted that the exotic chickens require expensive inputs as a result of
which, it is becoming increasingly difficult to sustain the poultry industry
over the years under a poor economy .The prevalent high
Turkey
farming is very popular in the Western countries. The major producing countries
are the United States of America, Germany, France, Italy, Netherlands and the
United Kingdom. In 2004, the estimated world turkey meat production was 4.94
million tonnes (Central Poultry Development Organization, 2008). However,
Nigeria’s contribution to the above statistic is not known. Commercial breeds
and strains of turkeys such as Broad Breasted Bronze, Broad Breasted White,
White Nicholas 300, Big-6, Hybrid Large White and a host of others have been
developed by University Research Stations and reputable commercial turkey
breeding companies in the Western world. Strong preference and elaborate
research reports have been focused on these modern turkeys as a result of which
they have been highly bred for
Commercial
turkey production in Nigeria is still rudimentary. The reason for this apparent
low production seems to be due to lack of appreciation of its potential role in
meat production and national economy or perhaps lack of understanding and
knowledge of its management and production requirements (Abeke and Ubani,
2008). In Nigeria, turkey is a premium bird. Both local and exotic breeds are
highly valued. Although some level of commercial production is evident, small
stock-holder producers dominate the turkey industry. Commercial producers develop
their flock structures with prolific exotic “broiler” strain. Back-yard and
medium scale farmers operate with local types and exotic broiler strains in
small flock units.
One of the
major challenges facing turkey production in Nigeria and other developing
countries is the low capability of the species to reproduce by natural mating.
Breeders who rely on natural mating procedures often encounter poor results due
to the clumsy nature of the toms as a reproductive partner. Modern turkey hens
throughout the world are bred by artificial.....
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