Page 461 - Demo

SECTION II. APPLIED BIOTECHNOLOGY IN THE PHARMACEUTICAL INDUSTRY... 465The results show that calves born in spring have a slightly higher average weaning age (80.14 days) compared to winter (79.16 days). The weaning weight of calves born in spring is significantly higher (96.61 kg) compared to winter (90.60 kg). The average daily gain (ADG) of calves born in spring is also higher (0.76 kg/day) compared to winter (0.71 kg/day).These results indicate that the birth season has a significant impact on calf development, especially weaning weight and growth rate. Calves born in spring tend to develop better than those born in winter, possibly due to factors such as feed quality, environmental conditions, and seasonal herd management. Olson et al. (2009) [4] pointed out that the birth weight of HF calves is influenced by many factors, such as maternal nutrition during pregnancy, birth season, and parity.3.2.2. Determining the influence of birth weight, weaning day, and birth season on weaning ageThe impact levels of factors such as birth weight, weaning day, and birth season on weaning age are shown in the following analysis of variance (ANOVA) table:Table 5. ANOVA table determining the influence of birth weight, weaning day, and birth season on the weaning age of HF calves raised in Phu YenSource DF Seq SS Adj SS Adj MS F PWeight gain (kg/calf/day) 1 0.3957 3.1994 3.1994 743.67 0.000Weaning weight (kg) 1 3.1041 3.0619 3.0619 711.69 0.000Season 1 0.0087 0.0087 0.0087 2.03 0.156Error 337 1.4499 1.4499 0.0043Total 340 4.9584S = 0.0655914 R-Sq = 70.76% R-Sq(adj) = 70.50%