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  • ThesisItemOpen Access
    Development of a suitable model for ascertaining the growth and egg production in quails
    (Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 1991) John Thomas, M; KAU; George, K C
    An investigation was carried out into the growth and egg production aspect of Japanese quails at the Kerala Agricultural University Poultry Farm, Mannuthy on 1st February, 1989 with the following objectives. 1. to find a suitable relationship between age and body weight. 2. to investigate the" trend of egg production in quails through suitable mathematical models. ,3. to study the impact of climate parameters (temperature, ; , humidity) on egg production in quails. The birds were reared under uniform feed formula and ^identical management practices (recommended by Kerala Agricul tural University Package of Practices). The investigation mainly depended on' data consisting of weekly body weights of -ii^-dividual birds, daily egg production of birds (beginning from age at sexual maturity) and daily climatological para meters (temperature and humidity) from beginning till the end of experiment of 30th September, 1989. Mathematical models such as linear, quadratic, exponential, .Von-Bertalanffy, modified exponential, logistic and Gompertz were fitted for the purpose using body weights of ) individual birds as well as average body weights over twelve weeks and the fitted models were compared using coefficient of 2 determination (r ) and standard error of estimate(s). Mathematical models such as linear, exponentialf parabolic exponential, inverse polynomial. Gamma function. Gamma-type functic^n, quadratic function, quadratic function in logari'thmic scale, quadratic-cum-log, emperical and linear hyperbolic functions were fitted for the development of suitable models for ascertaining egg production using total weekly, fortnightly egg production, hen housed and hen day egg production and fitted models were compared using Furnival index, r^ and s. Multiple linear regression equation was fitted using average weekly egg production per bird as dependent variable and weekly temperature and humidity as explanatory variable to study the impact of climatological parameters on egg production in quails. The investigation has the following, salient features. (i) The hatching weight of Japanese quails were 7.1369 g. (ii) The females weighed more than the males during the entire period of experiment and the body weights have shown an increasing trend. At the end of 12th week the average body weights of males and females were 157.6552 g and 179.2500 g respectively. (iii) Rao's method justified that initial body weights • had no significant effect on growth rate. • (iv) Gompertz curve = a exp [-b exp(-kt)'] was most , suitable for , ascertaining growth in quails on individual basis as well as on the basis of • average body weights over twelve weeks. (v) Average age at sexual maturity (females) was found to be approximately 10 weeks and on an average the eggs weighed 12.20 g. (vi) Quadratic function in logarithmic scale ; = a f b(logJ^) + c(log^)^ was most suitable , for ascertaining egg production in quails (weekly, , fortnightly, hen housed and hen day production • basis). (vii) Climatic parameters had significant impact on egg production in quails.
  • ThesisItemOpen Access
    Comparative study of lactation curves in goats
    (Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 1991) Anita, S; KAU; George, K C
    Based on the weekly milk yield data of 20 weeks duration over different parities of the seven yenetic groups viz. Alpine Malabari, Malabari, Saanen Malabari, F2A , F2S, F3A and F3S maintained at the KAU, Goat Farm during the period 1976-'87, the following objectives were investigated. 1. To fit various lactation curve models in different breeds of goats and to select the most suitable one 2. To suggest a procedure for predicting complete lactation yield using various part lactation yields, 3. To study the effect of genetic and non-genetic factors on milk production traits. 4. To compare the persistency of milk yield among the selected breeds. On the basis of the criterions I, r and s eleven types of fitted lactation curves were compared. Among the curves compared the quadratic-cum-log and linear hyperbolic functions were selected as the best two curves for the genetic groups,Alpine Malabari, Malabari, F2A, F2S, F^A while for genetic groups Saanen Malabari and F^S the linear hyperbolic and quadratic log scale functions were the best two selected curves. As the linear hyperbolic function was found to be suited for all breeds under study it was selected as the best fitted curve for goats. Taking various cumulative part records of 4, 8 and12 weeks the linear hyperbolic function was then fitted to the parity-wise and pooled data of the seven genetic groups. It revealed that efficiency of over 98 per cent was achieved for all the part records though the efficiency increases with each added part record and hence this function could be selected as a prediction equation for the prediction of total yield from part record. Based on the ANOVA obtained by a two way classified non orthogonal data analysis the breed, order of lactation and their interaction were found to have significant influence on average yield. Among the breeds Saanen Malabari and among the parities fourth parity were found to be significantly different from the others and have the highest average weekly yield. Among the four methods used for comparing the seven genetic groups by calculating the persistency index, three methods (except method II) gave Saanen Malabari as the highest persistent one. By method II the highest index was attained by F^S followed by Saanen Malabari. Since Saanen Malabari gave the highest yield for pooled and individual parity data it was selected as the most persistent and high yielding breed.
  • ThesisItemOpen Access
    Pooled analysis of dependent sets of data
    (Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 1991) Sukumaran, K; KAU; Gopinathan Unnithan, V K
    A new methodology for the analysis of data generated from experiments in which observations constitute repeated measurements from the same experimental unit at different points of time was developed. The problem of dependence of error terms in successive observations was taken care of in the model for analysis itself. The model included regression of error terms on those in the yester years/seasons. The error mean square from this model was derived using principle of least squares. The proposed method was compared with the widely adopted split-plot analysis and its superiority discussed. The method was illustrated using data generated from an experiment conducted to compare three varieties of alfalfa laid out in RBD with six replications and observations taken in four consecutive seasons. The superiority of the new method over the split-plot analysis was evident in the example considered.
  • ThesisItemOpen Access
    Development of a suitable model for ascertaining the growth and egg production in quails
    (Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 1991) John Thomas, M; KAU; George, K C
    An investigation was carried out into the growth and egg production aspect of Japanese quails at the Kerala Agricultural University Poultry Farm, Mannuthy on 1st February, 1989 with the following objectives. 1. t.o find a suitable relationship between age and body weight. 2. to investigate the trend of egg production i n quails through suitable mathematical models. 3. to study the impact of climate parameters (temperature, humidity) on egg production in quails The birds were reared under uniform feed formula and I identical management practices (recommended by Kerala Agricultural University Package ;of Practices). The investigation mainly depended on data consisting of weekly body weights of individual birds, daily egg production of birds (beginning from age at sexual maturity) and daily climatological parameters (temperature and humidity) from beginning till the end of experiment of 30th September, 1989. Mathematical models such as linear, quadratic, exponential, Von-Bertalanffy, modified exponential, logistic and Gompertz were fitted for the purpose using body weights of individual birds as well as average body weights over twelve weeks and the fitted models were compared using coefficient of determination (r^) and standard error of estimate(s). Mathematical models such as linear, exponential, parabolic exponential, inverse polynomial, Gamma function, Gamma-type functicn, quadratic function, quadratic function in logarithmic scale, quadratic-cum-log, emperical and linear hyperbolic functions were fitted for the development of suitable models for ascertaining egg production using total weekly, fortnightly egg production, hen housed and hen day egg production and fitted models were compared using Furnival . 2 index, r and s. Multiple linear regression equation was fitted using average weekly egg production per bird as dependent variable and weekly temperature and humidity as explanatory variable to study the impact of diimatological parameters on egg production in quails.