Abstract
Background
The aim of this study was to evaluate whether different methods of providing eubiotic feed additives, to neonatal calves during the preweaning period, can improve the health, performance, rumen fermentation, and metabolic status of the calves. Forty-four Holstein-Friesian dairy calves, were divided into one of four treatment groups for the 8 week trial. The eubiotic feed additives consisted of a combination of probiotic Lactobacillus spp. (multiple-strains) at a dose of 250 mg/calf/d and phytobiotics containing rosmarinic acid, as the main bioactive compound, at a dose of 50 mg/calf/d. Treatment differed by the methods that the eubiotic feed additives were provided, and the groups were as follows: CON (control, without eubiotic feed additive in their milk replacer or their starter feed), MR (eubiotic feed additives added to the milk replacer), SF (eubiotic feed additives added to the starter feed), MRS (eubiotic feed additives added to the milk replacer and the starter feed). Individual intake of starter feed was measured daily and body weights weekly until 56 d of age.
Results
The body weight of the MR treatment group calves were higher on days 28 and 56. Including the eubiotic feed additive in the milk replacer affected increasing average daily gain, starter intake and total dry matter intake from d 29 to d 56 and the overall experimental period in comparison to the CON group. The calves of the MR treatment had lower fecal scores from d 3 to d 28, number of parasite oocysts/cysts per gram of feces on d 28, and the occurrences of faecal consistency scores of 3 (mild diarrhea) and 4 (confirmation diarrhea) were 3.2 and 3.0 times lower, respectively, compared with animals of the CON group. Also, in this group higher ruminal concentrations of total volatile fatty acids, propionate, and butyrate were noted on d 56 compared to CON group. Adding eubiotics into milk replacer resulted the highest concentrations of blood insulin-like growth factor-I and β-hydroxybutyrate from d 29 to 56 and through the entire experimental period.
Conclusion
The addition of eubiotic feed additives into the milk replacer can improve health, performance, rumen fermentation, and biochemical blood indices in dairy calves during the preweaning period.
Different Methods of Eubiotic Feed Additive Provision Affects Health, Performance, Fermentation, and Metabolic Status of Dairy Calves During The Preweaning Period
