| Objective: in recent years,the beef industry in our country has been developing towards the modern and large-scale breeding mode,and the stock of beef cattle has been increasing.Growth promoters have become an important factor affecting the economic benefits of pastures.The experiment was carried out under intensive feeding conditions,the intramuscular injection of dibutyryl cyclic adenosine monophosphate-calcium or dietary Sodium Stearoyl Lactate in fattening beef cattle was studied,the differences of ADG,DMI,serum concentration of immunoglobulins,blood biochemical indices and serum concentration of free amino acids were compared between the experimental group and the control group,to evaluate the effects of dbcAMP-Ca and SSL on growth performance,humoral immunity,blood biochemical indices and serum concentration of free amino acids in fattening beef cattle.Method: The experiment was carried out on a large scale cattle farm,twenty-eight healthy 12 month old male beef cattle with a body weight of 406.8 ±13.2 kg were randomly allotted to four groups,they were randomly divided into 4groups with 7 heads in each group.The experimental group A was injected with dbcAMP-Ca(0.2 mg/kg)once every 4 days.The experimental group A was intramuscular injected with dbcAMP-Ca(0.2 mg/kg)once every 4 days.The control group A was injected with the same volume of saline at same time,blood samples were collected every 4 days and serum was isolated.The experiment lasted 32 days.The experimental group B beef cattle supplemented with 30 g SSL on basal diet,control group B beef cattle do not do any treatment,blood samples were collected every 10 days and serum was isolated.The experiment lasted 60 days.All the tested beef cattle were fed normally according to the NRC(2000)standard.Twenty-nine blood biochemical indices such as Ig G,IgM,TP,BUN,Asp,Gly,Ile,Phe,Ser,Thr,Trp and Val were detected.At the beginning of the experiment and the end of the experiment,all the tested cattle were weighed on an empty stomach,DMI,BW,ADG and F:G were recorded and calculated.Results:(1)growth performance: the total weight gain and ADG of beef cattle in the experimental group A was significantly higher than that of the control group A(P< 0.05),and the F:G was significantly lower than that of the control group A(P <0.05).The total weight gain and ADG of beef cattle in the experimental group B was significantly higher than that of the control group B(P < 0.01),DMI was significantly higher than that in control group B(P < 0.05),and the F:G was significantly lower than that of the control group B(P < 0.01).(2)Serum immunoglobulin: the serum IgG content in the experimental group A was significantly higher than that in the control group A on the 28 d and 32 d(P < 0.05);the serum Ig M content in the experimental group A was significantly higher on the 20 d and 32 d than in the control group A.(P < 0.05).There was no significant difference in serum Ig A,IgG,IgM content test between the experimental group B and the control group B within 60 d(P > 0.05).(3)Blood biochemical indicators: the serum BUN concentration in the experimental group A was significantly lower than that in the control group A on the28 d and 32 d(P < 0.05);the serum TP concentration in the experimental group A was significantly higher on the 24 d and 32 d than in the control group A(P < 0.05).The concentration of serum TP in experimental group B was significantly higher than that in control group B at 60 d(P < 0.01),and the level of serum BUN in experimental group B showed an increasing tendency,but there was no significant difference(P >0.05);at the 60 d,the level of serum TC in experimental group B was significantly lower than that in control group B(P < 0.05);At the 40 d and 60 d,the serum HDL-C level in experimental group B was significantly higher than that in control group B(P< 0.05).(4)Serum free amino acids: compared with the control group A,serum Asp levels in the experimental group A decreased significantly on the 24 d and 32 d(P <0.05);on the 32 d,serum Gly and Ser levels in the experimental group A were significantly lower than the control group A(P < 0.05);on the 24 d and 32 d,serum Ile Thr,Trp and Val levels in the experimental group A were significantly higher than in the control group A(P < 0.05);on the 32 d,the serum Phe level was significantly higher in the experimental group A than in the control group A(P < 0.05).Conclusion: beef cattle with intramuscular injection of dbcAMP-Ca(0.2 mg/kg)every 4 days,the metabolism of amino acid and protein in beef cattle during fattening period can be improved,enhance the humoral immune function.Adding 30 g SSL to the diet of fattening beef cattle period could promote lipid metabolism of beef cattle.The growth performance of beef cattle was significantly promoted by two kinds of materials with different metabolic pathways;the average daily gain of beef cattle supplemented with SSL was significantly higher than that of dbcAMP-Ca injection group,however,the F:G of the SSL group is higher than that of dbcAMP-Ca group. |
PDF Full Text Request