| This report describes the first stage of a study that aims to identify traditional Chinese herbal medicines (TCHM) that may improve rumen function in cattle. Twenty different traditional Chinese herbal medicines were mixed with ground alfalfa and subjected to an in vitro gas production assay. The herbs and alfalfa hay were ground to 0.1 mm using a Wiley mill. Each syringe contained 200 mg of premixed herb and alfalfa powder (11%, 6%, 3% and 1.5% w/w), or alfalfa powder only (control), plus rumen fluid and buffer. All samples were incubated in triplicate at 39°C for 72 hours. Gas production data were fitted to the equation y = a +b (1 - e-ct), where y = gas produced at time "t", a = the gas production from the immediately soluble fraction, b = the gas production from the insoluble fraction, c = the gas production rate constant for the insoluble fraction, and t = incubation time. The data were fitted using the Solver function of Excel, and effects of TCHM on parameters were analyzed using the General Linear Model (GLM) procedure and Bonferroni Simultaneous Tests (Minitab v. 15, Minitab, Inc., State College, PA). At 11% w/w, several herbs exhibited gas production rate constants that differed significantly (P < 0.05) from those for controls: air potato rhizome, coptis root, licorice root and Chinese astragalus root. Several herbs also had significant effects (P < 0.05) on the insoluble fraction: isatis root, Chinese skullcap root and coptis root. Based on these preliminary data, some TCHM appear capable of altering rumen fermentation.;A variety of plant extracts and direct-fed microbials have been shown to improve the growth performance and feed efficiency of animals, though with inconsistent results. This report describes the second stage of a study of natural products that may improve digestive function, health, and performance in beef cattle. Sixty Angus X Hereford steers (298.5 kg initial BW) at approximately 8 months old were kept in individual pens (2.9 m x 6.7 m) for 70 days and fed a standard starter diet supplemented with garlic oil (GAR; 8 ml steer -1 day-1), licorice root powder (LIC; 120 g steer -1 day-1), a yeast-based probiotics product (PRO; 10 g steer-1 day-1), RumensinTM (RUM; 0.6 g steer-1 day-1; positive control), or no additives (CON; negative control). Overall ADG was estimated as the slope of body weight against days on feed, and the treatment effect was insignificant (P = 0.43). However, when compared to the CON group, overall ADG increased (P = 0.11) by 7.8% for the RUM. For the first two weeks of the trial, ADG for the RUM and PRO steers and the gain to feed ratio for the RUM group increased (P < 0.1) compared to those for the CON animals when using initial body weight as a covariate. In addition, the molar proportion of acetate in rumen fluid decreased ( P < 0.1) in the RUM group compared to the CON animals. Serum bIL-1beta concentrations were lower (P < 0.1) for the RUM and PRO animals than for the CON animals. When initial percentage of intramuscular fat was used as a covariate, the final percentage of intramuscular fat decreased by 12.2% for steers fed GAR and increased by 11.6% and 10.6% for steers fed RUM and PRO compared to the CON group, respectively (P = 0.02). There were no significant differences between the CON animals and the animals in any treatments in term of final body weight, DMI, DM digestibility, rumen fluid pH, propionate and butyrate concentrations, LM area, rib-fat, and rump-fat thickness. Given these results, RUM has once again proven its efficacy; moreover, the natural treatments did have minor effects on animal performance. The lack of results in certain categories was probably a result of the insufficient numbers of animals. Other results indicate that RUM and PRO have the potential to alter proinflammatory cytokine profiles and that GAR may alter VFA profiles and decrease body fat deposition. (Abstract shortened by UMI.)... |
