A total of 1931 normal first lactation records of Holstein Friesian cows kept at Dena Farm in Egy... more A total of 1931 normal first lactation records of Holstein Friesian cows kept at Dena Farm in Egypt during the period from 1987 to 1994 were used to estimate phenotypic and genetic parameters for 90 day milk yield (90 dMY), 305 day milk yield (305 dMY) and lactation period (LP). In addition, 76 bulls with at least ten daughters were used to compare three methods of sire transmitting ability. A least Squares analysis of variance show significant effect of month and year of calving and age at first calving for different traits studied, except the effect of age at first calving on LP. Heritability estimates for 90 dMY, 305 dMY and LP were 0.39 ± 0.08, 0.27 ± 0.07 and 0.14 ± 0.05, respectively. Genetic and phenotypic correlations between different traits were positive and significant. Sires with at least ten daughters were evaluated by best linear unbiased prediction (BLUP), least Squares means (LSM) and regression of the future daughters mean on the present daughters mean. The product moment correlations between different traits studied were positive and high (= 0.96).
Pakistan Journal of Biological Sciences, May 15, 2000
A total of 3236 lactation records of 929 Holstein Friesian cattle sired by 290 bulls kept at a co... more A total of 3236 lactation records of 929 Holstein Friesian cattle sired by 290 bulls kept at a commercial herd in Egypt (Dalla Farm) were used. Cows transmitting abilities (CTA) were estimated by best linear unbiased prediction (BLUP). All cows whose at least two records up to six were used. Means of 90 day milk yield (90 dMY) and 305 day milk yield (305 dMY) are 1673 to 25 and 5076±64 kg, respectively. Least squares analysis of variance showed a significant effect of month of calving, year of calving and parity as fixed effects and sire and cow within sire as random effects on 90 dMY and 305 dMY. Heritability, repeatability, genetic and phenotypic correlations were estimated by paternal half sibs correlations. Heritability estimates were 0.31 to 0.06 and 0.15±0.05 for 90 dMY and 305 dMY, respectively. Repeatability estimates were 0.25 ti 0.02 and 0.34±0.02 for 90 dMY and 305 dMY, respectively. Genetic and phenotypic correlations between the two traits studied were 0.47±0.12 and 0.53, respectively. Estimates of CTA for 90 dMY ranged from-513 to 556 kg and from-989 to 1754 kg for 305 dMY with the range being 1069 and 2743 kg, respectively. Product moment correlation between 90 dMY and 305 dMY was 0.92. The present results indicated that CTA for 90 dMY was good predictor of CTA for 305 d MY.
Atil, H., Khattab, AS. and Gevrekci, Y. 2005. A comparison of different selection indices for gen... more Atil, H., Khattab, AS. and Gevrekci, Y. 2005. A comparison of different selection indices for genetic improvement of some dairy milk traits in Holstein Friesian cows in Turkey. J. Appl. Anim. Res., 27: 117-120. A total of 1680 first lactation records of Holstein Friesian cows sired by 206 bulls maintained at five herds in Turkey were used to estimate phenotypic and genetic parameters for 305 day milk yield (305 dMY), lactation period (LP) and age at first calving (AFC). Data were analysed using Multiple Trait Derivative Free Restricted Maximum Likelihood (MTDFREML). The model included the fixed effects of herd, season and year of calving and parity, AFC as a covariate and individual and residual as random effects. Genetic correlations between 305 dMY and AFC; and LP and AFC were 0.90 and-0.95, respectively. Phenotypic correlations among all traits studied were generally similar to the corresponding genetic correlations. Index Il incorporating 305 dMY, LP and AFC was the best (RIH=O.75). It is recommended that selection should be exercised at the end of the first lactation.
Objective: The objective of this study was to estimate the lactation curves of Saanen goats by us... more Objective: The objective of this study was to estimate the lactation curves of Saanen goats by using individual milk yields in the early, mid and 0-6 months periods of lactation. For this purpose, Wood’s lactation curve was used to estimate lactation yields. Material and Methods: Milk yields of Saanen goats in different periods of lactation were estimated. For this purpose, the Wood’s lactation curve model was adapted to a total of 480 milk yield measured at 14-day intervals of 40 Saanen goats. Milk yields of goats in the first three months of lactation in January-March, mid-lactation in April-June, and 0-6 months in January-June were estimated. Results: According to the harmony of Wood's model, the determination of coefficient values of the estimations of milk yields in the first, mid-lactation and 0-6 months of lactation are 0.84, 0.87 and 0.84, respectively. The root mean square errors of Wood's model are 0.91 for the first period of lactation, 0.81 for the mid-lactation ...
Kafkas Universitesi Veteriner Fakultesi Dergisi, 2015
Various methods have been developed to achieve the most suitable solution in the face of challeng... more Various methods have been developed to achieve the most suitable solution in the face of challenges of constantly changing living conditions. Fuzzy logic is one of these methods and frequently preferred by researchers in recent years. Fuzzy logic is based on artificial intelligence modeling the information that includes uncertainty in the most appropriate mindset of people, especially in the decision making process. It also offers flexible and realistic perspectives to people. In this study, a fuzzy logic-based decision support system designed using reproduction and milk yield records of Holstein Friesians. Inputs of designed system are 305-day milk yield (305 DMY), calving interval (CI), service period (SP), artificial insemination (AI), dry period (DP). Output of the system is determined as classification decision. Similarities between expert and system decisions were investigated. Kappa statistics were used for this purpose and fitting value was found as 92.6% (P<0.05).
Kafkas Universitesi Veteriner Fakultesi Dergisi, 2014
Gelişen toplum yapısı ile birlikte gerçek hayatta yaşanılan sorunlar ve olaylara bakış açıları da... more Gelişen toplum yapısı ile birlikte gerçek hayatta yaşanılan sorunlar ve olaylara bakış açıları da değişmektedir. İnsanlar sorunlarını sahip oldukları sözel ve sayısal verileri kullanarak çözmekte ve bunun için çeşitli yöntemlerden yararlanmaktadırlar. Matematiksel yöntemler insanlara kesinlik içeren durumlarda sorunların çözümlenmesinde sayısal verileri analiz ederek yardımcı olurken, belirsizlik içeren durumlarda yetersiz kalabilmektedir. Son yıllarda kalite değerlendirilmesi gibi belirsizlik içeren durumlarda ortaya çıkan problemlerin çözümünde sıklıkla kullanılan bulanık mantık, yapay zeka yöntemlerinden bir tanesidir. Klasik mantık teorisine göre daha esnek bir yapıya sahip olan bulanık mantık teorisi, olayları nesnelere "0" ve "1" arasında atadığı doğruluk dereceleri ile açıklamakta böylece sözel ve sayısal veriler arasında bir bağ oluşturmaktadır. Bu çalışmada, çiğ süt örneklerinin kalite sınıflarına ayrılmasını amaçlayan bulanık mantık tabanlı bir karar destek sistemi geliştirilmiştir. Sistemin girdileri çiğ süt örneklerine ilişkin toplam bakteri sayısı, somatik hücre sayısı ve protein miktarlarının ölçülen değerleridir. Tasarlanan bulanık sistemin çıktısı ise çiğ süt kalite değerlendirmesi şeklindedir. Yapılan analizin başarısını belirlemek amacıyla uzman kararları ile karşılaştırma yapılmış ve sistemin %80 değerinde başarılı olduğu görülmüştür. Sistemin modellenmesi Matlab (sürüm R2010b) programı kullanılarak yapılmıştır.
Journal of Agricultural Faculty of Gaziosmanpasa University
Path Analizi, süt sığırcılığı başta olmak üzere hayvancılık alanında yaygın kullanılan yöntemler ... more Path Analizi, süt sığırcılığı başta olmak üzere hayvancılık alanında yaygın kullanılan yöntemler arasındadır. Modelde bulunan bağımlı ve bağımsız değişkenlerin birbirleri üzerinde doğrudan ve dolaylı etkilerinin hesaplanmasında kullanılan bu yöntem araştırmacılara oldukça ayrıntılı yorumlama imkânı sunmaktadır. Bu çalışmada, 1007 baş Holstein ırkı süt sığırına ilişkin laktasyon sayısı, buzağılama mevsimi, kuru dönem, servis periyodu ve tohumlama sayısı değişkenlerinin 305-gün süt verimi üzerine doğrudan ve dolaylı etkileri Path analizi ile araştırılmıştır. Çalışmanın analizleri IBM SPSS 26.0 ve IBM SPSS AMOS 21 programı ile gerçekleştirilmiştir. Laktasyon sırası (-0.061) ve buzağılama mevsimi (0.027) değişkenlerinin 305-gün süt verimi üzerine doğrudan etkilerinin istatistiksel açıdan anlamlı olmadığı görülmektedir (p>0.05). Kuru dönem (-0.354), servis periyodu (-0.505) ve tohumlama sayısı (0.386) değişkenlerinin 305-gün süt verimi üzerine doğrudan etkilerinin istatistiksel açıdan...
A total of 3748 normal lactation records of Friesian cows kept at Sakha farm, belonging to Animal... more A total of 3748 normal lactation records of Friesian cows kept at Sakha farm, belonging to Animal Production Research Institute, Ministry of Agriculture, Dokki, Cairo, Egypt during the period from 2000 to 2006 were used in the present study. Data was analyzed by using Multiple Traits Derivative Free Restricted Maximum Likelihood (MTDFREML) according to Boldman et al. (1995) using repeatability animal model. Two models were used. Model 1 includes month and year of calving and parity as fixed effects and direct genetic, maternal genetic, covariance between direct and maternal genetic and residual as random effects. Model 2 is similar to Model1, while additive maternal and covariance between direct and maternal effects were omitted from the model. Estimates of heritability for 305 day milk yield, lactation period, fat % and protein % were 0.33, 0.02, 0.16 and 0.64, respectively for model 1, while the values were 0.34, 0.03, 0.17 and 0.65, respectively as estimated from model 2. The removal of additive maternal genetic effects and covariance between direct and maternal genetic effects from the model increased estimates for heritability of additive genetic effects by 0.01, for the four traits. Therefore, the additive maternal genetic effect and covariance between direct and maternal genetic effects do not seem to make important contributions to the phenotypic variance for milk yield and it's composition.
ecision trees are one of the widely used methods in data mining approaches for data classifying a... more ecision trees are one of the widely used methods in data mining approaches for data classifying and estimating. The regression tree technique is a decision tree algorithm that examines the relationship between independent variables and each other and the dependent variable and summarizes the results with a tree diagram. In this study, effects of cage, hatching period, line, age of sexual maturity (ASM) and body weight of sexual maturity (BWSM) on egg production were examined by Classification and regression tree analysis (CART). 1980 layers were used from a commercial flock in Turkey. Regression tree analyses showed that the most significant variable affecting egg production was age of sexual maturity and it is followed by hatch trait. Average egg production was estimated 105.805±0.29 for layers that has smaller than or equal to 172.5 day age of sexual maturity, whereas this value was determined to be 73.848±2.47 for layers which has larger age of sexual maturity than 172.5 day. The...
Mathematical models of growth curves are useful because they provide a means to visualize pattern... more Mathematical models of growth curves are useful because they provide a means to visualize patterns of growth over time, and because they can be used to predict expected weight of a group of animals at a specific age (TZENG and BECKER, 1981). For the biologist who wants to describe weight-age relationships for growing animals, there are several growth models available. Growth models that describe S-shaped, asymptotic growth patterns include Bertalanffy (BERTALANFFY, 1960), Gompertz (FRANCE and THORNLEY, 1984; LAIRD, 1965), Richards (RICHARDS, 1959) and Logistic (GROSSMAN et al., 1985; GROSSMAN and BOHREN, 1985; MEAD et al., 1993). New nonlinear models with slightly different properties appear regularly. GROSSMAN and BOHREN (1982) compared several mathematical functions describing growth curves of chickens. KOOPS (1986) introduced multiphasic growth curve analysis, and a multiphasic growth function was examined to describe mean body-weight-gain curves of chickens (GROSSMAN and KOOPS, ...
Fuzzy logic has a great potential for researchers and it has been developed over the last two dec... more Fuzzy logic has a great potential for researchers and it has been developed over the last two decades. In animal science, there are limited numbers of studies on fuzzy logic approach. This study was carried out to examine the Fuzzy logic applications for prediction of the egg production data. Egg production records were obtained from the commercial poultry farm in Izmir, Turkey. Egg production traits of brown laying hens at 22 to 40 weeks of age were analyzed with Fuzzy logic system. In this study, Fuzzy logic model was developed for the prediction of egg production values of three classes; top, middle and lower (bottom for the cage effect) production. For this purpose 120 data lines representing 4 inputs consisting of cage, age at sexual maturity (ASM), body weight at sexual maturity (BWSM), body weight at mature age (BW) and 1 output, egg production (EP) that collected daily and individually were used in a Fuzzy logic model. The similarities between predicted and original producti...
A comparison of different selection indices for genetic improvement of some dairy traits in Fries... more A comparison of different selection indices for genetic improvement of some dairy traits in Friesian cattle in Egypt By A. S. KHATTAB and 2. A. SULTAN Genetic improvement in several traits can be most effectively accomplished if the information about those traits is combined into an index of net merit or total score. HAZEL and LUSH (1942) showed that the selection index was the most efficient method for selection in farm animals. Many different forms of selection indices have been suggested. The traits involved vary according to their relative importance for a particular sitution BASU et al. (1982). The purpose of this study was to(1) investigate non-genetic factors affecting 305-day milk yield (305MY), lactation period (LP), and age at first calving (AFC), (2) estimate the genetic and phenotypic parameters for these traits and (3) construct a set of selection indices to be used for the impro1,ement of milk production in Friesian cattle under local conditions. Material and methods Records of the Friesian herd at Sakha Experimental Farm, Animal Production research, Ministry of Agriculture were used in this study. Data were collected over the period from 1972 to 1988 and they comprised 1317 normal first lactations. The average number of daughters per sire was 8.3. Abnormal records affected by diseases such as mastitis and udder troubles or by disorders such as abortion were excluded. Traits included in this study were 305MY, LP and AFC. Data were analysed using the Mixed Model Least Squares and Maximum Likelihood Computer Program of HARVEY (1977). The model used for the analysis included the effects of year and season of calving as fixed, age at first calving as covariate and sire as random on 305MY and LP. The effects of year and season of birth as fixed and sire as random were included in the model used for the analysis of AFC. SULTAN and KHATTAB (1989) gave a detailed of the material and management of that herd. Estimates of sire and remainder components variance and covariance were computed according to Method I1 of HENDERSON (1953). Estimates of heritability was calculated as four times the ratio of (J', (sire variance components) to the sum of ozs and (J '~ (remainder variance component). Standard error of heritability was calculated using an approximate formula described by SWIGER et al. (1964). Genetic and phenotypic correlations were computed by LSML 76 of HARWY (1977). The estimates of phenotypic and genetic variance and covariance for 305MY, LP and AFC were used for the construction of several indices. A-Economic values The economic weight of milk is calculated on net profit of milk yield because in Egypt payment is based on yield only without regard to composition. (i) Cost of production of one U.S.
A total of 1931 normal first lactation records of Holstein Friesian cows kept at Dena Farm in Egy... more A total of 1931 normal first lactation records of Holstein Friesian cows kept at Dena Farm in Egypt during the period from 1987 to 1994 were used to estimate phenotypic and genetic parameters for 90 day milk yield (90 dMY), 305 day milk yield (305 dMY) and lactation period (LP). In addition, 76 bulls with at least ten daughters were used to compare three methods of sire transmitting ability. A least Squares analysis of variance show significant effect of month and year of calving and age at first calving for different traits studied, except the effect of age at first calving on LP. Heritability estimates for 90 dMY, 305 dMY and LP were 0.39 ± 0.08, 0.27 ± 0.07 and 0.14 ± 0.05, respectively. Genetic and phenotypic correlations between different traits were positive and significant. Sires with at least ten daughters were evaluated by best linear unbiased prediction (BLUP), least Squares means (LSM) and regression of the future daughters mean on the present daughters mean. The product moment correlations between different traits studied were positive and high (= 0.96).
Pakistan Journal of Biological Sciences, May 15, 2000
A total of 3236 lactation records of 929 Holstein Friesian cattle sired by 290 bulls kept at a co... more A total of 3236 lactation records of 929 Holstein Friesian cattle sired by 290 bulls kept at a commercial herd in Egypt (Dalla Farm) were used. Cows transmitting abilities (CTA) were estimated by best linear unbiased prediction (BLUP). All cows whose at least two records up to six were used. Means of 90 day milk yield (90 dMY) and 305 day milk yield (305 dMY) are 1673 to 25 and 5076±64 kg, respectively. Least squares analysis of variance showed a significant effect of month of calving, year of calving and parity as fixed effects and sire and cow within sire as random effects on 90 dMY and 305 dMY. Heritability, repeatability, genetic and phenotypic correlations were estimated by paternal half sibs correlations. Heritability estimates were 0.31 to 0.06 and 0.15±0.05 for 90 dMY and 305 dMY, respectively. Repeatability estimates were 0.25 ti 0.02 and 0.34±0.02 for 90 dMY and 305 dMY, respectively. Genetic and phenotypic correlations between the two traits studied were 0.47±0.12 and 0.53, respectively. Estimates of CTA for 90 dMY ranged from-513 to 556 kg and from-989 to 1754 kg for 305 dMY with the range being 1069 and 2743 kg, respectively. Product moment correlation between 90 dMY and 305 dMY was 0.92. The present results indicated that CTA for 90 dMY was good predictor of CTA for 305 d MY.
Atil, H., Khattab, AS. and Gevrekci, Y. 2005. A comparison of different selection indices for gen... more Atil, H., Khattab, AS. and Gevrekci, Y. 2005. A comparison of different selection indices for genetic improvement of some dairy milk traits in Holstein Friesian cows in Turkey. J. Appl. Anim. Res., 27: 117-120. A total of 1680 first lactation records of Holstein Friesian cows sired by 206 bulls maintained at five herds in Turkey were used to estimate phenotypic and genetic parameters for 305 day milk yield (305 dMY), lactation period (LP) and age at first calving (AFC). Data were analysed using Multiple Trait Derivative Free Restricted Maximum Likelihood (MTDFREML). The model included the fixed effects of herd, season and year of calving and parity, AFC as a covariate and individual and residual as random effects. Genetic correlations between 305 dMY and AFC; and LP and AFC were 0.90 and-0.95, respectively. Phenotypic correlations among all traits studied were generally similar to the corresponding genetic correlations. Index Il incorporating 305 dMY, LP and AFC was the best (RIH=O.75). It is recommended that selection should be exercised at the end of the first lactation.
Objective: The objective of this study was to estimate the lactation curves of Saanen goats by us... more Objective: The objective of this study was to estimate the lactation curves of Saanen goats by using individual milk yields in the early, mid and 0-6 months periods of lactation. For this purpose, Wood’s lactation curve was used to estimate lactation yields. Material and Methods: Milk yields of Saanen goats in different periods of lactation were estimated. For this purpose, the Wood’s lactation curve model was adapted to a total of 480 milk yield measured at 14-day intervals of 40 Saanen goats. Milk yields of goats in the first three months of lactation in January-March, mid-lactation in April-June, and 0-6 months in January-June were estimated. Results: According to the harmony of Wood's model, the determination of coefficient values of the estimations of milk yields in the first, mid-lactation and 0-6 months of lactation are 0.84, 0.87 and 0.84, respectively. The root mean square errors of Wood's model are 0.91 for the first period of lactation, 0.81 for the mid-lactation ...
Kafkas Universitesi Veteriner Fakultesi Dergisi, 2015
Various methods have been developed to achieve the most suitable solution in the face of challeng... more Various methods have been developed to achieve the most suitable solution in the face of challenges of constantly changing living conditions. Fuzzy logic is one of these methods and frequently preferred by researchers in recent years. Fuzzy logic is based on artificial intelligence modeling the information that includes uncertainty in the most appropriate mindset of people, especially in the decision making process. It also offers flexible and realistic perspectives to people. In this study, a fuzzy logic-based decision support system designed using reproduction and milk yield records of Holstein Friesians. Inputs of designed system are 305-day milk yield (305 DMY), calving interval (CI), service period (SP), artificial insemination (AI), dry period (DP). Output of the system is determined as classification decision. Similarities between expert and system decisions were investigated. Kappa statistics were used for this purpose and fitting value was found as 92.6% (P<0.05).
Kafkas Universitesi Veteriner Fakultesi Dergisi, 2014
Gelişen toplum yapısı ile birlikte gerçek hayatta yaşanılan sorunlar ve olaylara bakış açıları da... more Gelişen toplum yapısı ile birlikte gerçek hayatta yaşanılan sorunlar ve olaylara bakış açıları da değişmektedir. İnsanlar sorunlarını sahip oldukları sözel ve sayısal verileri kullanarak çözmekte ve bunun için çeşitli yöntemlerden yararlanmaktadırlar. Matematiksel yöntemler insanlara kesinlik içeren durumlarda sorunların çözümlenmesinde sayısal verileri analiz ederek yardımcı olurken, belirsizlik içeren durumlarda yetersiz kalabilmektedir. Son yıllarda kalite değerlendirilmesi gibi belirsizlik içeren durumlarda ortaya çıkan problemlerin çözümünde sıklıkla kullanılan bulanık mantık, yapay zeka yöntemlerinden bir tanesidir. Klasik mantık teorisine göre daha esnek bir yapıya sahip olan bulanık mantık teorisi, olayları nesnelere "0" ve "1" arasında atadığı doğruluk dereceleri ile açıklamakta böylece sözel ve sayısal veriler arasında bir bağ oluşturmaktadır. Bu çalışmada, çiğ süt örneklerinin kalite sınıflarına ayrılmasını amaçlayan bulanık mantık tabanlı bir karar destek sistemi geliştirilmiştir. Sistemin girdileri çiğ süt örneklerine ilişkin toplam bakteri sayısı, somatik hücre sayısı ve protein miktarlarının ölçülen değerleridir. Tasarlanan bulanık sistemin çıktısı ise çiğ süt kalite değerlendirmesi şeklindedir. Yapılan analizin başarısını belirlemek amacıyla uzman kararları ile karşılaştırma yapılmış ve sistemin %80 değerinde başarılı olduğu görülmüştür. Sistemin modellenmesi Matlab (sürüm R2010b) programı kullanılarak yapılmıştır.
Journal of Agricultural Faculty of Gaziosmanpasa University
Path Analizi, süt sığırcılığı başta olmak üzere hayvancılık alanında yaygın kullanılan yöntemler ... more Path Analizi, süt sığırcılığı başta olmak üzere hayvancılık alanında yaygın kullanılan yöntemler arasındadır. Modelde bulunan bağımlı ve bağımsız değişkenlerin birbirleri üzerinde doğrudan ve dolaylı etkilerinin hesaplanmasında kullanılan bu yöntem araştırmacılara oldukça ayrıntılı yorumlama imkânı sunmaktadır. Bu çalışmada, 1007 baş Holstein ırkı süt sığırına ilişkin laktasyon sayısı, buzağılama mevsimi, kuru dönem, servis periyodu ve tohumlama sayısı değişkenlerinin 305-gün süt verimi üzerine doğrudan ve dolaylı etkileri Path analizi ile araştırılmıştır. Çalışmanın analizleri IBM SPSS 26.0 ve IBM SPSS AMOS 21 programı ile gerçekleştirilmiştir. Laktasyon sırası (-0.061) ve buzağılama mevsimi (0.027) değişkenlerinin 305-gün süt verimi üzerine doğrudan etkilerinin istatistiksel açıdan anlamlı olmadığı görülmektedir (p>0.05). Kuru dönem (-0.354), servis periyodu (-0.505) ve tohumlama sayısı (0.386) değişkenlerinin 305-gün süt verimi üzerine doğrudan etkilerinin istatistiksel açıdan...
A total of 3748 normal lactation records of Friesian cows kept at Sakha farm, belonging to Animal... more A total of 3748 normal lactation records of Friesian cows kept at Sakha farm, belonging to Animal Production Research Institute, Ministry of Agriculture, Dokki, Cairo, Egypt during the period from 2000 to 2006 were used in the present study. Data was analyzed by using Multiple Traits Derivative Free Restricted Maximum Likelihood (MTDFREML) according to Boldman et al. (1995) using repeatability animal model. Two models were used. Model 1 includes month and year of calving and parity as fixed effects and direct genetic, maternal genetic, covariance between direct and maternal genetic and residual as random effects. Model 2 is similar to Model1, while additive maternal and covariance between direct and maternal effects were omitted from the model. Estimates of heritability for 305 day milk yield, lactation period, fat % and protein % were 0.33, 0.02, 0.16 and 0.64, respectively for model 1, while the values were 0.34, 0.03, 0.17 and 0.65, respectively as estimated from model 2. The removal of additive maternal genetic effects and covariance between direct and maternal genetic effects from the model increased estimates for heritability of additive genetic effects by 0.01, for the four traits. Therefore, the additive maternal genetic effect and covariance between direct and maternal genetic effects do not seem to make important contributions to the phenotypic variance for milk yield and it's composition.
ecision trees are one of the widely used methods in data mining approaches for data classifying a... more ecision trees are one of the widely used methods in data mining approaches for data classifying and estimating. The regression tree technique is a decision tree algorithm that examines the relationship between independent variables and each other and the dependent variable and summarizes the results with a tree diagram. In this study, effects of cage, hatching period, line, age of sexual maturity (ASM) and body weight of sexual maturity (BWSM) on egg production were examined by Classification and regression tree analysis (CART). 1980 layers were used from a commercial flock in Turkey. Regression tree analyses showed that the most significant variable affecting egg production was age of sexual maturity and it is followed by hatch trait. Average egg production was estimated 105.805±0.29 for layers that has smaller than or equal to 172.5 day age of sexual maturity, whereas this value was determined to be 73.848±2.47 for layers which has larger age of sexual maturity than 172.5 day. The...
Mathematical models of growth curves are useful because they provide a means to visualize pattern... more Mathematical models of growth curves are useful because they provide a means to visualize patterns of growth over time, and because they can be used to predict expected weight of a group of animals at a specific age (TZENG and BECKER, 1981). For the biologist who wants to describe weight-age relationships for growing animals, there are several growth models available. Growth models that describe S-shaped, asymptotic growth patterns include Bertalanffy (BERTALANFFY, 1960), Gompertz (FRANCE and THORNLEY, 1984; LAIRD, 1965), Richards (RICHARDS, 1959) and Logistic (GROSSMAN et al., 1985; GROSSMAN and BOHREN, 1985; MEAD et al., 1993). New nonlinear models with slightly different properties appear regularly. GROSSMAN and BOHREN (1982) compared several mathematical functions describing growth curves of chickens. KOOPS (1986) introduced multiphasic growth curve analysis, and a multiphasic growth function was examined to describe mean body-weight-gain curves of chickens (GROSSMAN and KOOPS, ...
Fuzzy logic has a great potential for researchers and it has been developed over the last two dec... more Fuzzy logic has a great potential for researchers and it has been developed over the last two decades. In animal science, there are limited numbers of studies on fuzzy logic approach. This study was carried out to examine the Fuzzy logic applications for prediction of the egg production data. Egg production records were obtained from the commercial poultry farm in Izmir, Turkey. Egg production traits of brown laying hens at 22 to 40 weeks of age were analyzed with Fuzzy logic system. In this study, Fuzzy logic model was developed for the prediction of egg production values of three classes; top, middle and lower (bottom for the cage effect) production. For this purpose 120 data lines representing 4 inputs consisting of cage, age at sexual maturity (ASM), body weight at sexual maturity (BWSM), body weight at mature age (BW) and 1 output, egg production (EP) that collected daily and individually were used in a Fuzzy logic model. The similarities between predicted and original producti...
A comparison of different selection indices for genetic improvement of some dairy traits in Fries... more A comparison of different selection indices for genetic improvement of some dairy traits in Friesian cattle in Egypt By A. S. KHATTAB and 2. A. SULTAN Genetic improvement in several traits can be most effectively accomplished if the information about those traits is combined into an index of net merit or total score. HAZEL and LUSH (1942) showed that the selection index was the most efficient method for selection in farm animals. Many different forms of selection indices have been suggested. The traits involved vary according to their relative importance for a particular sitution BASU et al. (1982). The purpose of this study was to(1) investigate non-genetic factors affecting 305-day milk yield (305MY), lactation period (LP), and age at first calving (AFC), (2) estimate the genetic and phenotypic parameters for these traits and (3) construct a set of selection indices to be used for the impro1,ement of milk production in Friesian cattle under local conditions. Material and methods Records of the Friesian herd at Sakha Experimental Farm, Animal Production research, Ministry of Agriculture were used in this study. Data were collected over the period from 1972 to 1988 and they comprised 1317 normal first lactations. The average number of daughters per sire was 8.3. Abnormal records affected by diseases such as mastitis and udder troubles or by disorders such as abortion were excluded. Traits included in this study were 305MY, LP and AFC. Data were analysed using the Mixed Model Least Squares and Maximum Likelihood Computer Program of HARVEY (1977). The model used for the analysis included the effects of year and season of calving as fixed, age at first calving as covariate and sire as random on 305MY and LP. The effects of year and season of birth as fixed and sire as random were included in the model used for the analysis of AFC. SULTAN and KHATTAB (1989) gave a detailed of the material and management of that herd. Estimates of sire and remainder components variance and covariance were computed according to Method I1 of HENDERSON (1953). Estimates of heritability was calculated as four times the ratio of (J', (sire variance components) to the sum of ozs and (J '~ (remainder variance component). Standard error of heritability was calculated using an approximate formula described by SWIGER et al. (1964). Genetic and phenotypic correlations were computed by LSML 76 of HARWY (1977). The estimates of phenotypic and genetic variance and covariance for 305MY, LP and AFC were used for the construction of several indices. A-Economic values The economic weight of milk is calculated on net profit of milk yield because in Egypt payment is based on yield only without regard to composition. (i) Cost of production of one U.S.
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