| Twelve male adult semi-fine wool sheep with permanent rumen cannulas were used in a completely randomized design to determine effect of leymus chinensis, untreated maize stalk, maize stalk treated by micro-treatment and combation of urea and lime on characteristics of rumen fermention, degradability of DM and NDF in rumen, nutrient digestibility, intake and intake speed in trial one to trial four. Sheep were radomly divided into four groups with 3 sheep per group. The purpose of trial 5 was to detemine the influence of different roughages on growth perfermance of lamb. In this trial fifty growing crossbreed (Texel X local breed) lambs with average live weight of 27±0.85kg were randomly divided into five groups with 10 sheep per group.Trial 1 The concentration of volatile fatty acids and NH3-N, cellulase activity and pH value of ruminal fluid were measured at 0, 2, 4, 6 and 8h after feeding. The results showed that the change of pH value was similar, and had no significant difference (p>0.05) at the same time points among four groups. The peak value of NH3-N concentration appeared at 2h after feeding. Stalk treated by combination of urea and lime improved NH3-N concentration from 12.40 mg/100ml to 35.01 mg/100ml, which increased by 184%, and had significant difference (p<0.05) compared with other groups. Although mean of tolal VFA concentration was not significant difference (p>0.05) among four groups, the peak value of acetic concentration didn't appear at the same time, the peak value of leymus chinensis appeared at 2h after feeding, while the peak value of micro-treatment and combination of urea and lime appeared at 4h, the control at 6h. Cellulase activity of leymus chinensis, micro-treatment and combination of urea and lime advanced in 10.38%, 12.85% and 6.96% than control, respectively. The increasement extent of micro-treatment group was the most, but there was not significant difference (p>0.05) with control.Trial 2 The degradabilities of DM and NDF in rumen were measured by nylon bags .The results indicated that the degradabilities of DM and NDF increased gradually. Degradability of DM had significant difference (p>0.05) between group of leymus chinensis and control at all time points, and group of combination of urea and lime had significant difference (p>0.05) compared with control in DM degradability at 12h, 24h, 48h, and 72h, while the difference appeared at 72h between group of micro-treatmen and control. NDF degradability of leymus chinensis improved by 14.35%, 32.34%, and 27.30% at 24 h, 48h, and 72h than that of control, respectively. Meanwhile micro-treatment and combination of urea and lime had a little highter in NDF degradability than control, but different was not significance(p>0.05).Trial 3 Diet was composed of roughage completely. Apparent digestibilities of DM, NDF, and CPwere measured by sampling all feces. Leymus chinensis had significant difference (p<0.05) than control in apparent digestibility of DM, and micro-treatment and combination of urea and lime had no significant difference (p>0.05) compare with control, but apparent digestibility of DM increased by 1.78% and 13.47% than that of control, respectively. Leymus chinensis and stalk treated by combination of urea and lime had significant difference (p<0.05) compared with control in apparent NDF digestibility, while NDF apperent digestibility of micro-treatment stalk improve by 4.73%, but had no significant difference (p>0.05) than that of control. Compared with control, the groups of Leymus chinensis, combination of urea and lime and micro-treatment had significant difference in apparent CP digestibility (p<0.05), and advanced in 47.87%, 22.21% and 15.55%, respectively.Trial 4 In this trial the intake speed of Leymus chinensis and micro-treatment stalk were 4.19 g/min and 4.39 g/min, respectively, and had significant difference (p<0.05) compared with control. The group of combination of urea and lime increased by 11.76% than control, but didn't had significant difference (p<0.05). The intake of leymus chinensis, stalk treater by combination of urea and lime and micro-treatment stalk improve by 33.00%, 30.02% and 21.43% than that control, and each group had different significant (p<0.05) compared with control.Trial 5 There were five groups , control (untreated stalk ), micro-treatment, combination of urea and lime, mixture (stalk treated by combination of urea and lime:silage=l:l, stalk treated by combination of urea and lime contained 60% DM, while silage contaied 30% DM) and silage, in this trial. The results showed that the intake of micro-treatment stalk, stalk treated by combination of urea and lime, mixtue and silage increased by 8.64%, 3.70%, 13.58% and 16.05%, respectively. ADG of silage was the highest, which advance in 89.02% than that of control, and had significant difference 1 (p<0.05) compare with contra. ADG of mixture was 123.67 g/d which improved 50.82% than that of control, and had significant difference compared withcontrol (p<0.05). Although there was not significant different (p>0.05) compared with control, ADG of micro-treatment stalk and stalk treated by combination of urea and lime increased by 13.41% and 16.46% than that of control, respectively. |
