Importance of milk traits monthly records in estimation of sires breeding value. [M.Sc. thesis]

• Main Author: Radaković, A
• Format: Publication
• Language: Serbian
• Published: Novi Sad (Serbia) A. Radaković 2010
• Subjects: APTITUD LECHERA; APTITUDE LAITIARE; BOVIN LAITIER; BREEDING VALUE; DAIRY CATTLE; GANADO DE LECHE; GENETIC PARAMETERS; http://www.fao.org/aos/agrovoc#c_16117; http://www.fao.org/aos/agrovoc#c_2108; http://www.fao.org/aos/agrovoc#c_24276; http://www.fao.org/aos/agrovoc#c_24847; MILK PERFORMANCE; PARAIMETROS GENATICOS; PARAMATRE GANATIQUE; VALEUR GANATIQUE; VALOR GENATICO

Estimation and comparison of breeding values using two methods, method of standard lactation and method which is using Test Day records is performed. Data were obtained from records for three breeds, Holstein Friesian (2863 records), Red Holstein (1671 records) and Simmental breed (1501 records), collected from 18 farms in small dairy farm sector in Vojvodina (Serbia). Genetic parameters has been estimated for milk traits and also different influence of environmental effects, heard, year season and lactation/record parity effect is found. Heritability value at Holstein Friesian breed, for first, second and third lactation in whole and standard lactations were in range for highly heritable traits, except heritability for milk fat content in standard lactation. For Red Holstein breed, heritability values for yield were slightly lower than theoretical values, whilst at traits of content were significantly lower than theoretical one. At Red Holstein breed and Simmental breed, milk yield and protein yield in whole and standard lactations are in range of moderate heritable traits, and milk fat and protein content, which are highly heritable, in this population are very low. Correlation values for yield traits are strong and positive. Negative correlations are found between yield and content traits. BLUP sire model is used for estimation of breeding value and comparison is performed by using rank correlation.