Research Interests:
The present research was designed to examine the repeatability estimates of egg weight and egg shell weight of exotic layers at 25, 51, 72 weeks and overall ages of the bird. For this purpose, thirty birds were selected from the flock of... more
The present research was designed to examine the repeatability estimates of egg weight and egg shell weight of exotic layers at 25, 51, 72 weeks and overall ages of the bird. For this purpose, thirty birds were selected from the flock of layers in the Babcock University Teaching and Research Farm. A total of thirty (30) eggs were collected daily from the birds continuously for five (5) days of egg production, at each age 25, 51 and 72 weeks. The total number of eggs collected at each age was 150 and 450 for the total of three age periods. Data were collected on egg production traits for egg weight and egg shell weight. The mean values of the egg quality traits revealed an apparent increase for egg weight 55.02–63.29 g and egg shell weight 6.36–7.81 g with a corresponding mean combined data of bird of 60.17 g for egg weight and 7.26 g for egg shell weight. A significant positive genetic correlation was obtained among traits with linear regression equations at different age groups. General linear model procedure of statistical analytical system was used to obtain the variance components for the estimation of repeatability. High repeatability estimates were obtained when the age variance was included in the computation and low to moderate estimates were registered when the age variance was excluded from the computation. Since repeatability estimates from various production periods of egg weight and egg shell weight were low to moderate, these traits can be improved by mass selection there culminating in egg production with optimal quality.
Research Interests:
The present research was designed to examine heritability estimates of egg length, egg breadth and egg shape index under the influence of age variance for Bovan Nera Black laying chicken sat 25, 51, 72 weeks and overall mean ages of the... more
The present research was designed to examine heritability estimates of egg length, egg
breadth and egg shape index under the influence of age variance for Bovan Nera Black laying
chicken sat 25, 51, 72 weeks and overall mean ages of the bird. For this purpose thirty birds were
selected from the flock of layers in the Babcock University Teaching and Research Farm. A total of
thirty (30) eggs were collected daily from the birds continuously for five (5) days of egg production,
at each age 25, 51 and 72 weeks. The total number of eggs collected at each age was 150 and 450 for
the total of three age periods. Data were collected on egg production traits for egg length, egg
breadth and egg shape index. The mean values of the egg quality traits revealed an apparent
increase for egg length 4.05–4.65 cm and egg breadth 2.47–2.66 cm with a corresponding overall
mean data 4.38 cm for egg length and 2.56 cm for egg breadth; however, egg shape index recorded
decrease from 61.87 to 57.19 with a corresponding overall mean of 58.92. General linear model procedure
of statistical analytical system was used to obtain the variance components for the estimation
of heritability. High heritability estimates were obtained when the age variance was included in
the computation for overall mean and at 25 weeks for the studied traits, and at 72 weeks for egg
breadth and egg shape index when the age variance was excluded while low estimates were registered
at 51 for all traits, and at 72 for egg length and with the corresponding overall mean for
all traits when the age variance was excluded from the computation. The heritability estimates from different egg quality traits were low to high. Since some of the traits recorded low heritability values,
these traits can be improved by mass selection thereby culminating into egg production with
optimal quality.
breadth and egg shape index under the influence of age variance for Bovan Nera Black laying
chicken sat 25, 51, 72 weeks and overall mean ages of the bird. For this purpose thirty birds were
selected from the flock of layers in the Babcock University Teaching and Research Farm. A total of
thirty (30) eggs were collected daily from the birds continuously for five (5) days of egg production,
at each age 25, 51 and 72 weeks. The total number of eggs collected at each age was 150 and 450 for
the total of three age periods. Data were collected on egg production traits for egg length, egg
breadth and egg shape index. The mean values of the egg quality traits revealed an apparent
increase for egg length 4.05–4.65 cm and egg breadth 2.47–2.66 cm with a corresponding overall
mean data 4.38 cm for egg length and 2.56 cm for egg breadth; however, egg shape index recorded
decrease from 61.87 to 57.19 with a corresponding overall mean of 58.92. General linear model procedure
of statistical analytical system was used to obtain the variance components for the estimation
of heritability. High heritability estimates were obtained when the age variance was included in
the computation for overall mean and at 25 weeks for the studied traits, and at 72 weeks for egg
breadth and egg shape index when the age variance was excluded while low estimates were registered
at 51 for all traits, and at 72 for egg length and with the corresponding overall mean for
all traits when the age variance was excluded from the computation. The heritability estimates from different egg quality traits were low to high. Since some of the traits recorded low heritability values,
these traits can be improved by mass selection thereby culminating into egg production with
optimal quality.
Research Interests:
The present research was designed to examine the repeatability estimates of egg weight and egg shell weight of exotic layers at 25, 51, 72 weeks and overall ages of the bird. For this purpose, thirty birds were selected from the flock of... more
The present research was designed to examine the repeatability estimates of egg weight
and egg shell weight of exotic layers at 25, 51, 72 weeks and overall ages of the bird. For
this purpose, thirty birds were selected from the flock of layers in the Babcock University
Teaching and Research Farm. A total of thirty (30) eggs were collected daily from the birds
continuously for five (5) days of egg production, at each age 25, 51 and 72 weeks. The total
number of eggs collected at each age was 150 and 450 for the total of three age periods.
Data were collected on egg production traits for egg weight and egg shell weight. The mean
values of the egg quality traits revealed an apparent increase for egg weight 55.02–63.29 g
and egg shell weight 6.36–7.81 g with a corresponding mean combined data of bird of 60.17 g
for egg weight and 7.26 g for egg shell weight. A significant positive genetic correlation was
obtained among traits with linear regression equations at different age groups. General linear
model procedure of statistical analytical system was used to obtain the variance components
for the estimation of repeatability. High repeatability estimates were obtained when
the age variance was included in the computation and low to moderate estimates were registered
when the age variance was excluded from the computation. Since repeatability
estimates from various production periods of egg weight and egg shell weight were low to
moderate, these traits can be improved by mass selection there culminating in egg production
with optimal quality.
and egg shell weight of exotic layers at 25, 51, 72 weeks and overall ages of the bird. For
this purpose, thirty birds were selected from the flock of layers in the Babcock University
Teaching and Research Farm. A total of thirty (30) eggs were collected daily from the birds
continuously for five (5) days of egg production, at each age 25, 51 and 72 weeks. The total
number of eggs collected at each age was 150 and 450 for the total of three age periods.
Data were collected on egg production traits for egg weight and egg shell weight. The mean
values of the egg quality traits revealed an apparent increase for egg weight 55.02–63.29 g
and egg shell weight 6.36–7.81 g with a corresponding mean combined data of bird of 60.17 g
for egg weight and 7.26 g for egg shell weight. A significant positive genetic correlation was
obtained among traits with linear regression equations at different age groups. General linear
model procedure of statistical analytical system was used to obtain the variance components
for the estimation of repeatability. High repeatability estimates were obtained when
the age variance was included in the computation and low to moderate estimates were registered
when the age variance was excluded from the computation. Since repeatability
estimates from various production periods of egg weight and egg shell weight were low to
moderate, these traits can be improved by mass selection there culminating in egg production
with optimal quality.
Research Interests:
This paper was designed to estimate and model the ratio of photosynthetically active radiation (PAR) to global solar radiation (SR) over different climatic zones in Nigeria in order to assess the feasibility of PAR/SR availability and... more
This paper was designed to estimate and model the ratio of photosynthetically active radiation (PAR) to global solar radiation (SR) over different climatic zones in Nigeria in order to assess the feasibility of PAR/SR availability and utilization in agriculture, forestry and oceanography. The measured global solar radiation data was obtained from the Archives of the Nigerian Meteorological Agency, Oshodi, Lagos, over a period of thirteen years (2000-2012). Proven empirical models were used as a baseline for theoretical formulations and estimations of the ratio between PAR to SR over different climatic zones in Nigeria. From the estimated values, the mean Original Research Article Nwokolo et al.;JAERI, X(X): xxx-xxx, 2017; Article no.JAERI.30000 2 ratio of PAR/SR in rainy season recorded 0.5067, 0.4863, 0.4906, 0.4740, 0.4574 and 0.4528while the mean ratio of PAR/SR in dry season registered 0.4843, 0.4875, 0.4641, 0.4504, 0.4480 and 0.4482with annual ratio of 0.4974, 0.4868, 0.4811, 0.4651, 0.4535 and 0.4509for Port Harcourt, Enugu, Abeokuta, Ilorin, Bauchi and Sokoto respectively.The annual ratio of PAR/SR revealed that there is consistent increase in the ratios from NorthWest (Sokoto) to South-South (Port Harcourt). These variations were mainly due to apparent increase in cloudiness, aerosol particles and associated atmospheric moisture from the South-South to NorthWest with the apparent movement of the Hadley cell circulation system along the equatorial line form NorthWest to South-south. The models developed were found to estimate PAR/SR accurately from commonly available SR data and empirical model when tested with statistical indicators and compared with the results of researchers within and beyond tropical locations in Nigeria.