Title of the paper: Estimation of genetic parameters for test day records of milk performance traits in German Improved Fawn The objectives of this study were to estimate genetic parameters for milk performance traits of German Improved Fawn by using univariate und multivariate animal models. The analysis was based on 27,778 test day records of 1,848 German Improved Fawn with 3,574 lactation records distributed over 229 flocks in Lower Saxony, Saxony and Baden-Wuerttemberg. Milk records were sampled between 1988 and 2002. The animals in our analysis were the progeny of 455 sires and 1.148 does. Heritabilities estimated with a multivariate test day model with fixed regression were h² = 0.19, 0.16 and 0.15 for milk, fat and protein yield. For fat and protein content and Somatic Cell Score (SCS) heritabilities were h² = 0.17, 0.14 and 0.16, respectively. The additive genetic correlations between milk yield and fat as well as protein yield of German Improved Fawn were very high and positive (r g = 0.84 and r g = 0.77). Milk yield and milk contents were genetically negative correlated with r g = -0.28 for fat and r g = -0.22 for protein content. A moderate additive genetic correlation (r g = 0.48) between fat and protein content was estimated. There were no considerable additive genetic correlations between fat yield and protein content as well as between fat content and protein yield (r g = 0.05 and r g = 0.09). Additive genetic correlations between milk, fat or protein yield and SCS were high and negative, whereas additive genetic correlations between fat or protein content and SCS were low and positive. The genetic parameters estimated from field test records allow to achieve genetic progress in milk performance traits of German Improved Fawn.
Abstract. Title of the paper: Influence of systematic environmental effects on milk performance traits in German Improved Fawn The objectives of this study were to analyse the influence of fixed effects on milk traits of German Improved Fawn. The analysis was based on 27,778 test day records of 1,848 German Improved Fawn with 3,574 lactation records. The milk records were sampled between 1988 and 2002 from 229 flocks in Lower Saxony, Saxony and Baden-Wuerttemberg. The average daily milk yield was 2.87 ± 1.20 kg with a fat content of 3.08 ± 0.54% and a protein content of 3.38 ± 0.95%. Somatic cell count (SCC) was transformed into somatic cell score (SCS). Mean SCS was 5.49 ± 1.93. The average lactation length was 234.1 ± 76.4 days. The analysis of variance showed a significant influence of lactation number, stage of lactation, year of lambing and month of lambing on all analysed milk production traits. Milk yield was highest in the fourth lactation number and fat as well as protein content in the 7th to 13th lactation number. Litter size had a significant influence on milk and fat yield and on fat and protein content. The region significantly influenced protein yield and fat and protein content of German Improved Fawn but had no effect on milk and protein yield and SCS. Animals from Baden-Wuerttemberg reached the highest milk protein content but the lowest milk fat content.
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