Effect of exogenous melatonin on the cellular response of Holstein heifer calves during vaccination.

Despite rigorous vaccination protocols, calf morbidity is the primary contributor to economic loss in the calf sector of the dairy industry. Melatonin has modulated immune response in other mature animal species. We hypothesized that exogenous melatonin may improve the cellular response to vaccination in dairy calves.

The effects of a nutritional packet (live yeast, vitamins C and B1, and electrolytes) offered to steers in a calf-fed system on growth performance, nutrient digestion, feeding behavior, carcass characteristics, and ruminal variables.

Effects of a nutritional packet strategically offered to calf-fed system steers on growth performance, nutrient digestibility, feeding behavior, ruminal variables, and carcass characteristics were evaluated. Angus crossbred steer-calves ( = 60; body weight [BW] = 234 ± 4 kg) were used in a randomized complete block design (block = BW) and stratified into two treatments: 1) control; and 2) 30 g/steer-daily (dry matter [DM] basis) of a nutritional packet containing (steer-daily basis): Live yeast (; 1.7 × 10 CFU), vitamin C (Ascorbic acid, 162 mg), vitamin B1 (thiamin hydrochloride, 400 mg), sodium chloride (2.

Characterization of bacterial DNA identified in abscessed and non-abscessed bovine hepatic tissue at the time of harvest.

Bacteriological characterization of bovine liver abscesses has been accomplished by cultural methods but DNA methods are still needed, as many bacteria are not conducive to laboratory culture. In addition to this gap in research, there have been no studies which identify the bacterial presence within healthy, non-abscessed liver tissue. The objective of this study was to compare the bacteriome of both abscessed and non-abscessed bovine livers in an observational case-control study design.

Evaluation of immunoglobulin-Y in place of tylosin phosphate in the diets fed to Holstein Steers and preliminary analysis of liver abscess duration on animal growth performance.

Despite the regular use of feed-grade macrolide-antibiotics, bovine liver abscesses persist, representing a financial burden to pre- and post-mortem sectors of the beef industry. An immunoglobulin-Y () additive developed to target and was evaluated for the control of liver abscesses. Research is needed for the impact of liver abscess severity as well as abscess duration on steer performance and carcass characteristics.

Inclusion of quebracho tannin extract in a high-roughage cattle diet alters digestibility, nitrogen balance, and energy partitioning.

Condensed tannins (CT) might improve animal and system-level efficiency due to enhanced protein efficiency and reduced CH4. This study evaluated the impact of quebracho tannin (QT) extract fed at 0%, 1.5%, 3%, and 4.