The Effect Of Yeast Culture And Pellet Concentrate On The Growing Development Of Holstein Calves

The experiment was conducted to study the effect of yeast culture additive and pellet concentrate on Holstein calves' daily gain, body measurement indexes, feed nutrient digestive coefficient, serum biochemistry indexes and rumen and duodenal growing developmental physiology indexes. This experiment also explored a new feeding model of Holstein calves effectively.Totally random event trial design was adopted to complete this experiment. 18 heads of Holstein calves were divided into 3 groups, each group contained 2 males and 4 females. The parental generations' comprehensive constitution, date of birth and foetal order of corresponding trial calves were similar. The birth weight and body measurement indexes of corresponding trial calves were no significant difference(p > 0.05). Calves in group 1were fed by traditional model(power feed + guinea grass),fresh milk 4L/d and warm water, and were trained to ingest guinea grass freely; Calves in group 2 were fed with fresh milk 7L/d and warm water, and were trained to ingest pellet concentrate freely; Calves in group 3 were fed with fresh milk 7L/dand warm water, and were trained to ingest pellet concentrate added with yeast culture(20g/d). Calves in group 2 and group 3 were forbidden to contact guinea grass. Power feed and fresh milk were fed at 4:30, 11:30, 16:30 everyday. The experiment went on 60 days.After backgrounding, trial calves were weighted before morning feeding, and weighted again every 15 days. At the beginning and the end of this experiment, the body measurement (height at withers , body length , heart girth , circumference of cannon bone , width of pin bone width, hip width ) of each trial calf was measured and recorded. At the same time of the successive three days of the experiment's first day, 20th day, 40th day and 60th day, the fresh excrement of each trial calf was collected in order to be determined the nutrient digestibility. Each male trial calf was took 10ml blood sample from vein before morning feed, and tool again every 20 days. The blood samples were conserved in -30°C condition and prepared to be analysed the chemical compound. The trial male calves which would be dissected were put to death by draining of blood from carotid artery, then the ruminal and duodenal samples were prepared for making sections of organic tissues and determining rumen physiological indexes. All the data of this experiment was analysed by SPSS statistical software.The result indicated that average amount of DM intook of trial calves in three groups was no significant different(p > 0.05); Average daily gain of the calves in group 2 and group 3 was better than that in group 1 remarkably(p < 0.01), which in group 3 was better than that in group 2(p < 0.05); Average daily height at withers grow of the calves in group2and in group 3 was better than that in group l(p < 0.05); Average daily body length grow of the calves in group 2 was better than that in group land group 3 remarkably (p < 0.01); Average daily heart girth grow and average daily hip width grow of the calves in 3 were better than that in group 2(p< 0.01), which in group 2 were better than that in group 1 (p < 0.01); Average daily circumference of cannon bone grow of the calves in group 3 was better than that in group 1 and group 2(p < 0.05); Average daily width of pin bone width grow of the calves in group 3 was better than that in group 1 and group 2 remarkably(p < 0.01), which in group 2 was better than that in group l(p < 0.05).DM apparent digestibility, EE apparent digestibility and NDF apparent digestibility of the calves in group2 and group 3 were obviously higher than that in group l(p < 0.01);CP apparent digestibility of the calves in group 2 and in group 3 was obviously higher than that in group l(p < 0.01), which in group 2 was higher than that in group l(p < 0.05); GE apparent digestibility of the calves in group 3 was higher than that in group 1 and in group 2 (p < 0.05). ANF apparent digestibility of the calves in group 2 and in group 3 was obviously higher than that in group 1 (p < 0.05), which in group 2 and in group 3 was significant difference(p < 0.05).Blood serum indexes (blood sugar, urea nitrogen, total protein and serum protein) of the trial calves in group 1,group 2 and group 3 were no significant different(p > 0.05).Of ruminal and duodenal dissected physiological indexes, average area of rumen, average weight of rumen, average weight of reticulum, average weight of abomasums, total weight of stomach and average number of rumen papillae in unitary area were on significant difference(p > 0.05); average weight of omasum of the calves in group 3 exceeded that in group 1 and group 2(p < 0.05); average rumen thickness of the calves in group 2 exceeded that in group l(p < 0.05), which in group 1 exceeded that in group 3 (p < 0.05); average length of rumen papillae of the calves in group 3 was in excess of that in group 2(p < 0.05), which in group 2 was in excess of groupl(p < 0.05). From the physiology cutting slices photos of the trial calves' rumen and duodenum could be seen, the average growing development of rumen papillae in each sample spot of group 3 was better than that in group 1 and group 2, which ofthe calves in group 2 was better than that in group l;the duodenum papillae growing development of three groups were no significant difference.From the analysis, we can conclude that yeast culture could improve the internal environment of the trial calves' gastrointestinal track and the function of digestion. So that the average daily gain and body measurement were enhanced accordingly. In the condition of absorbed same amount of DM, the reason of calves who were fed with pellet concentrate could grow better than calves who were fed with power concentrate was that the relative nutrient concentration of pellet concentrate was higher.Before formatting perfect ruminal function, calves' digestive and metabolic capacity are similar to that of simple stomach animals, they can digest pellet concentrate and absorb nutrient efficiently. On the other hand, yeast culture can affect the digestive way in rumen and improve the digestive and absorbed efficiency of CP, NDF and ANF when they go through the gastrointestinal track. This phenomenon maybe connects with the function of yeast culture's stimulating the activity of beneficial microorganism in gastrointestinal track.The growing development of ruminal epithelial tissue which absorb VFA depends on the existence of VFA, especially butyric acid. Yeast culture contains AA, glucose, VB , organic acid, and etc., which can provide nutrient for the growth and metabolism of the beneficial microorganism in gastrointestinal track, and promote the production of VFA. The proper size of pellet concentrate is very important to the growth of rumen papillae, which can prevent rumen papillae cornification and reduce silting caused by power feed between rumen papillae.After being evaluated the economic performance of the experiment, a conclusion could be drew that feeding Holstein calves by using yeast culture additive and pellet concentrate could improve Holstein calves' growing development, shorten youthful dairy cows' breeding cycle and cut down feeding cost. The economic performance was very remarkable.