TY - JOUR AU - Hayward Sanfiorenzo, John PY - 1962/07/01 Y2 - 2024/03/29 TI - Evaluation of Six Breeding Lines of Milk Goats JF - The Journal of Agriculture of the University of Puerto Rico JA - JAUPR VL - 46 IS - 3 SE - Articles DO - 10.46429/jaupr.v46i3.12336 UR - https://revistas.upr.edu/index.php/jaupr/article/view/12336 SP - 205-212 AB - A multiple correlation analysis was conducted on milk production and on mortality data to evaluate the following six breeding lines of milk goats: Saanen, Native, 1/2 Saanen X 1/2 Native, 3/4 Saanen X 1/4 Native, 7/8 Saanen X 1/8 Native, and 1/2 Saanen X 1/4 Barbados X 1/4 Native. The sources of variation were: Breeding lines; year; age of does; and age of kids. These data included 155 records of 73 does and 375 records of kids, and covered the period from 1955 to 1959, inclusive. All lines outyielded at a highly significant level the milk production of the Native breed. The heaviest milk producer was the 3-way cross; 1/2 Saanen X 1/4 Barbados X 1/4 Native, followed closely by the Saanen breed, the 3/4 Saanen X 1/4 Native, and the 7/8 Saanen X 1/8 Native. Differences between lines mentioned were not significant. Highly significant differences in milk production were observed between ages of does. Milk production increased with age until 6 years of age. There were no data available after 6 years of age. Maximum milk production was obtained from does 4 to 6 years old. Variations in milk production among years were attributed, in part, to variations among the different age groups, and in part, to variations in environmental conditions beyond the control of the breeder. Differences in mortality percentages between lines were not significant. The 3-way cross, 1/2 Saanen X 1/4 Barbados X 1/4 Native, had the lowest mortality percentage, while the highest occurred in the 1/2 Saanen X 1/2 Native cross. Differences in mortality among years were not considered of importance. It was concluded that crowding and increased competition contributed to the variations observed. More kids died from 2 to 6 months of age than from birth to 1 month of age, and than from 7 to 12 months of age. These differences were significant at the 5-percent level. ER -