Effects of weaning at different ages on the growth of lambs and milk production of dams in the awassi breed of sheep
Significant differences were found between the groups in respect of weaning weight and 75 day weight but not for 6 month, 12 month and 16 month weights and fleece weight. Mean weaning weight in the group weaned at 45 days was 4.1 and 6.2 kg less than those in the groups weaned at 60 and 75 days, the same differences being 2.9 and 3.4 kg for mean 75 day weihgt. Retarded growth in the 45 day group became increasingly apparent as the lambs grew older, although group diferences were not significant at the later ages. The groups weaned at 60 and 75 days had similar mean weights throughout the experiment.
Mean total milk production and lactation length in the groups of ewes suckling their lambs for 45, 60 and 75 days were not significantly affected by the length of suckling period but significiant diferences for the amount of marketable milk were found between the groups. Mean values were; 131.5, 132.3 and 125.9 kg for total milk production; 81.4, 72.2 and 54.0 kg for the amount of marketable milk and 194.8, 191.7 and 197.0 days for lactation length in there groups, respectively.
These results indicate that the amount of marketable milk can be increased by reducing the length of suckling period but weaning at or earlier then 45 days may cause retarded growth in lambs. There does not seem to be much advantage to be gained by weaning lambs later than 60 days under the conditions of this experiment.
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