The phenotypic characterization of native Lesotho chickens

[摘要] English: Studies were made on growth, carcass and egg performance as well as mortality of the Lesotho native chickens compared to the South African native (Potchefstroom Koekoek, Ovambo, Lebowa-Venda and Naked Neck) and two exotic lines, namely the New Hampshire a nd Rhode Island Red from 3-days old to 70 weeks old (moulting). Chickens were raised in two batches with an interval of four weeks between the two batches: from 3-day old to ten and six in Batches 1 and 2, respectively. Chickens were reared in Bloemfontein (UFS) under confinement, fed ad libitum with broiler starter mash for the first four weeks where after grower mash was fed to the chickens up to the age of ten weeks old. From this stage until the end of the laying phase, they were all fed yellow maize and managed semi-intensively in Lesotho at the NULFOA. The study was done in two phases, namely the pre-laying and laying phases. With the exception of feed conversion ratio (FCR), which was conducted in the first 35 days of the study, all measurements of growth and egg performance traits were recorded weekly while mortality was recorded daily. Carcass yield analysis was done at 70 weeks of age. Presentation of the growth data was done in three stages, namely 3-day, 26-week and 70-week weights, which are considered crucial in a chicken's life span. The means of the Lesotho line were significantly different (p<0.05) from other lines in all growth traits, namely 3-day weight, 26-week weight, average daily gain (ADG) and average weekly gain (AWG) except for the FCR and hen weight at 70 weeks old. With the exception of the New Hampshire and Potchefstroom Koekoek, no significant differences (p>0.05) were observed between the Lesotho hen weight and other lines. The Ovambo had the highest body weight and avera ge daily gain of all the native populations at 26-weeks old, while the Potchefstroom Koekoek had the highest 70-week weight. Feed conversion ratios ranged between 3.2±1.9 for the New Hampshire to 3.9±1.2 for Naked Necks in Batch 1, and 3.3±1.2 for New Hampshire to 4.2±0.9 for the Lesotho line in Batch 2. All differences between the lines for FCR were highly significant (p<0.01). All the lines commenced their egg production between the 25th to 26th weeks of age and there were no significant differences (p> 0.05) between the ages at first lay among all the lines. Egg production was found to differ significantly (p<0.05) among the different lines. The average number of eggs laid per week per hen and egg weight of the Lesotho hens was 1.2 and 48.5g, respectively. The New Hampshire had a significantly (p<0.05) higher dressed weight than other lines (1903.0±190.8g) while the Naked Neck had the lowest (1297.7±133.0g). Bone and head weight were not significantly different (p>0.05) among the different lines. The Lesotho line had the highest overall mortality (89%) of all the lines. The lowest mortality (27%) was found in the Potchefstroom Koekoek. A probable reason for high mortalities in the Lesotho could be ascribed to the result of inbreeding within the line. Although the Lesotho hens exhibited the lowest growth at the onset of laying (1113.8±71.6g), they eventually compensated and ended being large (2047.5±65.6g) at 70-weeks old. The Lesotho hen, like the New Hampshire and Potchefstroom Koekoek showed potential for being a good dual-purpose breed, since it was able to maintain a high body weight at the end of laying. Therefore the breed has an advantage of fetching a higher market price at the end of laying. The constraint is that of their low growth in the earlier part of their life span. This can be improved through the implementation of planned breeding programs.

[发布机构] University of the Free State