Effects Of Forage Quality On Nutrient Digestibility And Growth Of Holstein Bull Calves

This paper selected 14 Holstein cattle with similar maternal body measurement, bodyweight and body measurement to study the effect of different quality forages on DMI, nutrient digestibility, bodyweight, growth body condition and growth development Holstein bull calves at the stage of suckle, 3-6months, 6-10 months and 10-18 month. The cattle were randomly divided into two groups (n=7). One group feed hay and named H group, the other group feed corn straw and named CS group.During suckle, H group had higher intake than CS group in forage (P<0.01), and concentrate intake was the same. There are no significance between the groups in nutrient digestibility (P>0.05). But NDF of H group was 11% higher than of CS group, they were 43.07% and 38.03% respectively. Daily average chest girth growth of H group was 6% higher than CS group (P>0.05). Daily average body weight growth of H group was 8% higher than CS group, they were 0.766Kg/d and 0.706Kg/d respectively (P>0.05).During the 3-6 months, the two groups both intake 2Kg concentration every day. H group had higher forage DMI than CS group (P<0.01).Each nutrient digestibility of H group was higher than CS group (P>0.05). There was significant difference in protein digestibility. Body condition of H group was better than CS group (P>0.05). Daily average body weight growth of H group was higher than of CS group, they were 0.788Kg/d and 0.522Kg/d respectively (P<0.01). Daily average body height growth of H group was higher than CS group by 26%, there were 0.088cm/d and 0.119cm/d (P>0.05).But there were significant differences both in the daily average body length and chest growth respectively.During the 6-10 months, under feeding the same quality of the forage, H group had higher forage DMI than CS group (P>0.05), each nutrient digestibility of CS group higher than of H group (P>0.05). Body condition of H group was better than of CS group (P>0.05). Daily average bodyweight of the two groups were 0.479Kg and 0.532Kg respectively, but there were no difference between the two groups. Daily average body height growth of H group was 14% higher than of CS group, they were 0.118cm and 0.102cm respectively. There were significant different between the two groups in daily average chest girth growth. Daily average body length of H groups was 7% higher than of CS group, they were 0.172cm and 0.160cm respectively. During the 10-18 months, under feeding the same quality of the forage, H group had higher forage DMI than CS group (P>0.05). Feeding hay, because of compensative growth, the intake improvement of CS group was higher than H group. Feeding slight silage, there were no significant difference between the two groups (P>0.05). There were no significant difference between the groups in ADF and CP digestibility (P>0.05), but there were significant difference in other nutrient digestibility (P<0.05). Daily average body height ,chest girth growth and body length of H group were 6% higher than of CS group, they were 0.053cm and 0.050cm; 0.107cm and 0.101cm; 0.110cm and 0.103cm. There were no significant differences between groups in those indexes (P>0.05).It was concluded that before the digest organs mature supply different quality forage had effect on growth. Feeding the same forage (hay and slight silage), supplied CS would improve nutrient digestibility for cattle. The major pattern of nutrient digestibility was CS group higher than H group (P>0.05). And body height, chest girth, body length of CS group lagged of H group for two to three months.