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(2.73 vs. 3.97 L and 523.8 vs. 535.4 kg, respectively

This study aimed to investigate the impact of pre-pubertal growth rate on pubertal characteristics of Sohagi ewe lambs. Thirty of Sohagi ewes lambs at 6-7 months of age were divided into three equal groups (n=10 per each group) according to its previous growth rate from birth to 6 months of age, groups marked as fast, medium and low growing. All groups were housed in closed barns with access to an open area and got their nutritional requirements depending on their growth stage. Results show that the pubertal characteristics of Sohagi ewe lambs at puberty were significantly affected (P<0.05) by the pre-pubertal growth rate. Ewe lambs in the fast-growing group were achieved to onset puberty firstly at 235 days on average then ewe lambs in the medium and low-growing group (242.6 and 269.4 days, respectively). Ewe lambs in the fast-growing group were the heaviest at puberty than ewe lambs in the medium and low-growing group (26.4 vs. 23.7 and 22.4 kg, respectively). Blood progesterone concentration was not significantly different among ewe lambs groups (1.419± 0.04 ng/ml on average, ranged from 1.203 to 1.737 ng/ml). In conclusion, results showed that the pre-pubertal growth rate of ewe lambs is one of the most influential factors affecting the development of puberty characteristics.

Sixteen yearling male buffalo calves weighing 160 kg were assigned to 2x2 factorial designs. Each four calf group was subjected to either long (16L:8D) or short (8L:16D) photoperiods and housed in individual or group system. The four groups were fed CFM and wheat straw. Feed intake and residual were recorded daily. Samples of feces and food ration were collected for analysis. Digestion coefficients, nutritive values and feed efficiency were calculated. Animals were weighed biweekly. Blood samples were collected monthly to determine total protein, albumin, globulin, ALT/GPT, AST/GOT and total cholesterol. Housing systems did not have any significant effects on calf body weight and growth rate while; photoperiod had significant effect (P≤0.01) on them. Housing systems did not have any significant effects on the digestion coefficients and nutritive values, while, photoperiod systems had highly significant (P≤0.01) effect on digestibility coefficients and nutritive values of buffalo calves. Calves exposed to long photoperiod (16L:8D) and housed in group pens were more efficient in converting feed to gain than calves exposed to short photoperiod (8L:16D) and housed in individual pens. Total protein (P≤0.05), albumin (P≤0.01) and ALT/GPT (P≤0.05) was significantly affected by the housing system. All blood parameters were not significantly affected except cholesterol level was significantly (P≤0.01) affected by photoperiod. The interaction between housing systems and photoperiods did not have any significant differences on growth performance, feed conversion efficiency or metabolic response. It could be concluded that rearing buffalo calves individually with increasing illumination period to 16 hours/ day may improve feed efficiency and growth performance without compromising the physiological status of the calves during the fattening period.

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