ESTIMATION OF GENETIC PARAMETERS FOR SEMEN CHARACTERISTICS IN RHODE ISLAND RED AND WHITE CHICKENS
ESTIMATION OF GENETIC PARAMETERS FOR SEMEN CHARACTERISTICS IN RHODE ISLAND RED AND WHITE CHICKENS
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Date
2006-05
Authors
MOHAMMED, KABIR.
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Abstract
Three hundred and sixty-one birds from five hatches at one week apart,
comprising one hundred and sixty-six cocks and one hundred and ninety-five hens were
used in this study which was conducted from October 2003 to September 2004. The hens
consisting of 85 birds from the male line (strain A) and 110 birds from the female line
(strain B) were monitored in individual cage units for egg production up to 280 days of
age. Similarly, the cocks which were made up of 73 birds from the male line (strain A)
and 93 birds from the female line (strain B) were subjected to semen collection using the
massage technique at 20, 25, 30 and 40 weeks of age. The ejaculates were then subjected
to both physical and chemical evaluations for semen quality analysis. The parameters
considered include body weight, shank length, semen volume, semen colour, semen
motility, semen concentration and total sperm output. Results showed that body weight
and shank length were consistent with each age period and this applies to both strains (A
and B). The mean semen volume and colour did not differ significantly (P>0.05) for both
strains throughout the experimental period. The mean (±SE) semen motility, sperm
concentration and total sperm output at 20 and 40 weeks of age were 73.833±2.725% and
71.755±2.725%; 1.175±0.130x109/ml and 1.407±0.105 x109/ml; 46.433±7.301 x109/ml
and 64.105±6.397 x109/ml respectively for strain A. Similarly, the values for strain B
were 74.605±2.199% and 67.397±2.532%; 1.358±0.094 x109/ml and 1.271±0.092
x109/ml; 53.250±6.714 x109/ml and 52.678±4.812 x109/ml respectively. Heritability from
sire component of variance for body weight (0.892± 0.731) and shank length
(0.505±0.066) at 20 weeks of age were high indicating that these traits are highly
heritable. Moderate to high heritability estimates were observed for semen volume,
semen colour and sperm motility. Positive genetic correlations between Osborne Index
and semen volume (1.059), Osborne Index and semen colour (0.727) as well as Osborne
Index and sperm motility (0.256) were also obtained. The genetic correlation between
Osborne Index and semen volume changed not only in magnitude but also in direction in
later periods. This work revealed that selection based on Osborne Index had no adverse
effect on semen quality traits of Rhode Island breeder cocks.
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Description
A THESIS SUBMITTED TO THE POSTGRADUATE SCHOOL,
AHMADU BELLO UNIVERSITY, ZARIA,
NIGERIA.
IN PARTIAL FULFILLMENT FOR THE AWARD
OF THE DEGREE OF MASTER IN ANIMAL SCIENCE
DEPARTMENT OF ANIMAL SCIENCE,
AHMADU BELLO UNIVERSITY,
ZARIA.
MAY,2006
Keywords
ESTIMATION,, GENETIC,, PARAMETERS,, SEMEN,, CHARACTERISTICS,, RHODE,, ISLAND,, RED AND WHITE,, CHICKENS.