The present study was conducted to determine some environmental factors affecting birth weight, weaning weight and daily live weight gain of Holstein calves of a livestock facility in Izmir, Turkey. The data on 2091 calves born between the years 2005-2010 were used to assess the relevant parameters. Effects of calving year, calving month, calf gender and the interaction between calving year and calving month on calves' birth weights were highly significant. The overall mean of birth weights was 39.6±0.15 kg. In addition, effects of calving year, calving month, gender, birth weight, weaning age, calving year x calving month, calving year x gender and calving year x calving month x gender interactions on weaning weight (WW) and daily live weight gain (DLWG) were highly significant. The overall means of WW and DLWG were respectively found to be 79.7±0.20 kg and 525±2.5 g. A one kilogram increase in birth weight resulted in an increase of 0.89 kg in weaning weight and a decrease of 1.26 g in daily live weight gain. Prenatal temperature-humidity index (THI) affected birth weight of calves (R 2 =0.67). Increasing THI from 50 to 80 resulted in 3.8 kg decrease in birth weight.

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A model including fixed and random linear regressions is described for analyzing body weights at different ages. In this study, (co)variance components, heritabilities for quail weekly weights and genetic correlations among these weights were estimated using a random regression model by DFREML under DXMRR option. Data of 1046 pedigreed quail were used. Individual live weights were obtained weekly from hatching to six weeks of age. Records for the same bird were taken as repeated measurements and single measurement error variance ( ) (co)variances. Heritability estimates for ages were moderate, ranging from 0.007-0.61 and estimated measurement error variance was 9.60 g 2 . Correlations were found positive among weights. Genetic correlations were higher than phenotypic and permanent environmental correlations. The correlations between adjacent periods are more closely correlated than between remote periods.

The present study was conducted to investigate the effects of calving season (winter and spring) and parity (first and second parity) on colostrum quality. Colostrum of 42 Holstein cows raised at a private dairy farm was used in this experiment. Calving season and parity had no effects on major components of colostrum. However, somatic cell count (SCC) and the brightness of the colostrum (L*) values were affected by calving season (P<0.05). The mean of winter colostrum SCC was lower than the spring season (P<0.05). The brightness of the colostrum was found to be higher in winter season than in spring season (P<0.01). Colostrometer has been used to evaluate colostrum quality and Brix refractometer and colorimeter can also be used to assess colostrum quality.