Abstract
Four experiments were conducted to achieve the stated objectives of the research projects. The
first experiment was conducted to evaluate the existing feeding and management practices of
crossbred cows, calves and heifers in semi-intensive system in Baghabarighat (Ullahpara) where
crossbred cows were reared extensively. Other three experiments (2 to 4) were conducted at
Bangladesh Agricultural University Dairy Farm with crossbred dairy heifers to monitor the
effects different levels of energy and protein on their performance. In experiment 1, data were
collected from three categories of dairy farms -small, medium and large. It was observed that
68, 30 and 2% farm owners were engaged in cropping, business and service respectively.
Farmers were found more interested to raise crossbred dairy cows than indigenous. The
average number of indigenous and crossbred cows per farm was 0.95 and 5.2 respectively. It
was observed that overall 81% farms had conventional, 12% pakka and 7% chapra type housing
system in the study area. Result showed that only 2% farms fed animals by grazing, 16% stall
feeding and 82% used both grazing and stall feeding system. Forty two percent farms did not
process feeds before feeding. It was observed that 47, 44 and 9% farms supplied 0.5, 1.5 and 2 kg
concentrates/d respectively. A total of 77, 100, and 75% small, medium and large farm holders
had separate house for calves respectively. Diarrhea, pneumonia, fever and naval rot were most
prevalent diseases in the study area. Experiment 2 was conducted to determine the energy
requirement for optimum growth of crossbred heifers. Twenty crossbred dairy heifers about
one year and two months old having similar body weight were used in a Complete
Randomized Design (CRD) with five treatments viz. ME 90, 80, 100, 110 and 120%, AFRC (1993)
representing T1, T2, T3, T4, and Ts respectively. Results showed that among the treatment groups
DMI and OMI were gradually increased (p<0.01) with increased ME level in the ration.
Accordingly CP and TDN also higher in the increasing level of ME at different treatment
groups. Maximum live weight gain (444g) was found at Ts (120% ME level group) and
minimum daily live weight gain (151g) at T2 (80% ME level group). Similarly heart girth, body
weight and wither height also were gradually increased (p<0.05) with increasing ME level of
the ration. In experiment three, different crossbred heifers of the same age (15±2months) and
weight assigned in a CRD with three dietary treatments 120%ME and CP less than 10%of 120%
of the AFRC (1993); 120%ME and CP 120% AFRC (1993); 120% ME, CP more than 10% of 120%
AFRC (1993), representing T₁,T2 and T3 respectively targeting growth rate of 0.5 kg /d. Dry
matter (DM) intake in T₁,T2 and T3 were 4.67, 4.78, 4.77 kg/d respectively that differed from
each other significantly(p<0.01).TDN intake were significantly (p<0.01) higher in T1 group. Live
weight gain 476(g/d), length increased (17.24cm) and wither height increments (5.94cm) were
found significantly higher in T2 group. Highest FCR was found in T2 (10.04:1) significantly
(p<0.01). Digestibility of OM increased with the increase of CP in diets. The digestibility of NFE
varied significantly (p<0.01) among the treatments. In experiment 4, eighteen cross breed dairy
heifers (18+2months age) having similar body weight were assigned in a CRD with three
dietary treatments viz. 120% ME, 120% CP with mustard oil cake; 120% ME, 120% CP with
soybean meal; 120% МE, 120% CP with fish meal representing T1, T2 and T3 respectively to
know the effect of source of protein on heifer performance. Growth target was 0.5 kg/d for each
group. Results showed that T2 group consumed more DM (5.46kg/d) along with more OM, МЕ
and CP than other groups significantly. Digestible OM intake was higher (2.77 kg/d) in Ti
group. Average daily gain was found high (457 kg/d) in T2 group. Heart girth was found
significantly (p<0.05) higher in T2 but body length increments was higher in Ti group. Less FCR
(14.65:1) was noticed in T3 group. It is evident from the outcome of these experiments that 120%
ME and 120% CP of AFRC (1993) would be suitable for optimum growth performance of
crossbred heifers, soybean meal and mustard oil cake can be used as cheaper source of protein
than fish meal.