نوع مقاله : مقاله پژوهشی
1 گروه علوم دامی، دانشکده کشاورزی، دانشگاه بیرجند
2 دانشیار پژوهشی بخش تحقیقات تغذیه و فیزیولوژی دام، موسسه تحقیقات علوم دامی کشور، سازمان تحقیقات، آموزش و ترویج ‏کشاورزی، ‏کرج، ایران
عنوان مقاله [English]
Background and objectives: Biochar is one of the carbon compounds that has been introduced as a suitable substitute for some food additives, including antibiotics. The purpose of this study was to investigate the effect of using different levels of a type of mineral Biochar from Kohbanan Biochar mine in Kerman on growth performance, digestibility of nutrients, some blood parameters and rumen fermentation of weaned Holstein calves.
Materials and methods: In the present study, 40 Holstein weaned calves (male and female) with an average age of 128±7 days and an average weight of 99.4 ± 0.4 kg were used in a completely randomized design with 4 treatments and 10 replications. Experimental treatments include: 1) basic diet without mineral Biochar (control diet), 2) basic diet with 0.33% mineral Biochar, 3) basic diet with 0.66% mineral Biochar, 4) The basic ration was with 1% mineral Biochar (all based on the percentage of dry matter of the ration). A two-week habituation period was considered. Weaned calves were weighed upon entering the design and weighing was repeated every two weeks until the end of the experiment. Calves were kept in individual stalls and fed experimental diets for three months. During the experiment, the feed consumed three times a day was provided to the calves at the limit of optional consumption. The amount of feed consumption was measured daily and average daily weight gain, average feed consumption and feed conversion efficiency were calculated. At the end of the experiment, a blood sample was taken from the jugular vein of the calves and blood parameters including urea nitrogen, glucose, total protein and triglyceride, albumin , alanine aminotransferase, aspartate transaminase, very low-density lipoprotein, low-density lipoprotein, and high-density lipoprotein were determined. Also, at the end of the test, the digestibility of dry matter, organic matter, protein Crude, insoluble fiber in neutral detergent, pH and ammonia nitrogen concentration of rumen liquid were measured.
Results: The results showed that the use of mineral Biochar in feeding weaned calves had no significant effect on dry matter consumption, daily weight gain, total weight gain and average feed conversion efficiency. The highest apparent digestibility of dry matter, organic matter, protein and insoluble fiber in neutral detergent was related to calves fed with a diet containing 1% Biochar (P< 0.05). The concentration of glucose, urea and high-density lipoproteins in the blood of calves fed with a ration containing one percentage of Biochar was higher than that of the calves of the control group (P<0.05). The concentration of cholesterol, triglyceride, aspartate transaminase, alanine aminotransferase, albumin, total protein, very low density lipoproteins, low density lipoproteins, gamma globulin did not differ significantly between the experimental groups. Also, calves fed with a diet containing 1% Biochar had more ammonia nitrogen and lower rumen pH than the control group (P< 0.05).
Conclusion: In general, the results of this experiment showed that the use of 1% mineral Biochar in the ration of weaned calves can have positive effects on digestibility, some blood parameters and rumen fermentation.