| This paper was aimed at the problem that how to scientifically used antibiotic milk to feed dairy calves, and was conducted to research the effects of feeding pasteurized β-lactam antibiotic milk on calves’ performance, blood indicators, gastrointestinal development and to explore the effect of feeding pasteurized β-lactam antibiotic milk to calves. That would provide theoretical basis for the scientific cultivation of calves, the optimal utilization antimicrobial milk, and reducing the cost of calves’ cultivation.(1) The effect of feeding pasteurized β-lactam antibiotic milk on calves’ growth performanceEighteen Holstein male calves with similar body weight and body height were selected and devided into one of two feeding groups with randomized design. The fresh antibiotic milk was pasteurized at 63-65°C for 30 min. The 9 Holstein male calves of control group were fed antibiotic-containing milk, and another half of experiment group were fed pasteurized antibiotic-containing milk from day 3 to 60 of life. The calf was weaned on 60 days of breeding period, and the experiment period was lasted 180 days. The fresh and pasteurized antibiotic milk was respectively collected and determined the milk composition content. Body weight and measurement were respectively measured on the days of 3, 30, 60, 90, and 180 in the calves’ growing period, and then calculated the average daily gain and measurement index.Fecal score was recorded at every day of preweaning, and then calculated the diarrhea rate in any period. The results showed that there were no significant influence of pasteurization on antibiotic milk lactose, lactoprotein, milk fat, total solid, blood urea nitrogen, somatic cell count and antibiotics content of β-lactam antibiotic milk(p>0.05). But, the living bacterium,escherichia coli and salmonella in antibiotic milk were all obviously decreased after pasteurizing(p<0.05). The calves’ ADG during 3 to 60 days of experiment group was higher than that of control group(p<0.05). The withers height on 60 days, chest on 90 and 180 days,trunk index on 180 days of experiment group were all higher than that of control group(p<0.05). But the leg index on 60 days of experiment group was lower than that control group(p<0.05). The calves’ fecal score and diarrhea rate during 3 to 10 days and 3 to 60 days of experiment group were all lower than that of control group(p<0.05). In addition, One calfconsumed milk 226.5 kg, the price at that time was 3.7 ￥/kg. So, each calf can save 838.05 yuan in lactation. It was concluded that the nutrients of β-lactam antibiotic milk according to pasteurizing, however, the living bacterium counts in antibiotic milk was obviously decreased.Feeding pasteurized antibiotic milk could reduce the diarrhea rate of calves, and to some extent improve the growth performance of calves, as well as save feeding costs.(2) The effect of feeding pasteurized β-lactam antibiotic milk on blood indicators of calvesBlood-sampling would be taken on calves’ breeding days of 7, 15, 30, 60, 90, and 180, and then measured blood indicators including glucose(GLU), blood urea nitrogen(BUN),triglycerides(TG), glutamic pyruvic transaminase(GPT), glutamic oxalacetic transaminase(GOT); and the immune indexes including Ig A, Ig M, Ig G, IL-1β, IL-2, IL-6, and TNF-α.Compared with control group, the calves’ serum GLU on 60 and 90 days, BUN on 15 days,GPT on 7 days and GOT on 90 days of life of experiment group were all significantly increased(p<0.05), but the TG on 90 days of life was significantly reduced(p<0.05). For the immune indicator, feeding pasteurized β-lactam antibiotic milk increased the level of Ig A on30 days, Ig M on 15 and 30 days, IL-1β on 15 days(p<0.05), reduced the level of Ig G on 30 days and IL-6 at 7 days(p<0.05). The experimental results proved that feeding pasteurized antimicrobial milk to a certain extent affect the body’s metabolism, but it is difficult to get a conclusion of effects on the immune system.(3) The effect of feeding pasteurized β-lactam antibiotic milk on gastrointestinal development of calvesThe Holstein male calves were slaughtered on 60, 90 and 180 days of breeding period. The p H value of rumen, abomasum, duodenum, jejunum, ileum, and cecum was respectively determined after opened abdominal cavity. The fresh weight of internal organs were determined, and then calculate organ indexes. Biopsy of rumen and intestine was taken respectivelsy of rumen and intestine was taken respectively, and then observed its morphological changes. The results proved that the weight of calves’ liver, spleen, stomachs,intestines, and the index of liver, spleen, stomach, duodenum, jejunum, ileum, colon and caecum in any test time between the control and experiment group were not significant different(p>0.05). Compared with the control group the jejunum index on 60 days wassignificantly increased(p<0.05). Feeding pasteurized β-lactam antibiotic milk was not affect the p H of rumen, abomasum, duodenum, jejunum, ileum and caecum in any test time(p>0.05).Feeding pasteurized β-lactam antibiotic milk was not affect the nipple height, nipple width,nipple area, mucosal thickness and muscular layer thickness of rumen dorsal sac and rumen ventral blind sac on 60, 90 and 180 days of calves’ life. Compared with control group, the duodenum villus height on 60 days and villous height/crypt depth(V/C) on 60 days were of experiment group were significantly improved(p<0.05); on the contrary, the crypt depth of duodenum on 90 days was significantly decreased(p<0.05). The jejunum villus width on 90 days and V/C on 90 and 180 days were all obviously improved(p<0.05); on the contrary,jejunum crypt depth on 60, 90 and 180 days was significantly decreased, respectively(p<0.05).The ileum histomorphology on 60, 90, 180 days of life between two groups were not significant different(p>0.05). It was concluded that feeding pasteurized β-lactam antibiotic milk to some extent could improve the gastrointestinal development of calf, mainly reflected in promoting development of small intestine morphology.The experiment results showed that the nutrients of β-lactam antibiotic milk according to pasteurizing, however, the living bacterium counts in antibiotic milk was obviously decreased.Feeding pasteurized antibiotic milk could reduce the diarrhea rate of calves, and to some extent improve the growth performance of calves, as well as save feeding costs, the impact on immune system still need further research, to a certain extent could improve the small intestine development of calf. |
PDF Full Text Request