Growth, ruminal measurements, and health characteristics of Holstein bull calves fed an Aspergillus oryzae fermentation extract

Abstract

A fermentation extract of the fungus Aspergillus oryzae can be used as a prebiotic. The objective was to determine if dietary inclusion of a fermentation extract of A. oryzae as well as calf age would alter growth, health, performance parameters, and the growth and development of the rumen in Holstein calves from birth thru 1 wk postweaning; it was hypothesized that it would. Purchased bull calves (n=52) that originated from 1 of 13 farms were used in this experiment. All calves had serum IgG greater than 10 mg/mL. Calves were randomly assigned to a slaughter age, 4 (n=16) or 8 wk (n=36), and treatment, control (n=27) or fermentation extract of A. oryzae (AMF; n=25). Calves were housed and fed individually; no bedding was used and no forage was fed. Calves assigned to AMF were fed 2 g of AMF daily. Liquid AMF was delivered in milk replacer for the first 4 wk of the study; solid AMF was top-dressed on texturized starter thereafter. Calves were fed nonmedicated milk replacer twice daily (22.0% crude protein, 20.0% fat, dry matter basis; 680 g/d) and were weaned upon consumption of 0.91 kg of starter (20% crude protein, 2.0% fat; medicated with decoquinate) for 3 consecutive days or on d 45 of the study, whichever came first. Calves had ad libitum access to starter and water throughout the study. Feed intake as well as fecal and respiratory scores were recorded daily; body weight, withers height, and hip height were recorded weekly. Gross rumen measurements and rumen samples for future gross and histological analyses were taken at 4 and 8 wk. All calves grew similarly; weaning age averaged 40.39±0.77 d. Lifetime average daily gain was 0.60±0.05 kg/d and lifetime gain-to-feed ratio was 0.56±0.05. Milk replacer, starter, total dry matter intake, gross and histological rumen measurements, rumen pH, fecal and respiratory scores, and total medical costs were not affected by treatment. Despite total medical costs not differing by treatment, a lower percentage of AMF calves were treated for respiratory ailments and respiratory treatment cost was lower for AMF compared with control. Several factors may have contributed to an overall lack of observed treatment effect in this study, including include the use of a low-forage (compared with concentrate) diet, immunocompetent calves, and the selected product dose and routes of delivery. Dietary inclusion (2 g/d) of an extract of A. oryzae did not affect calf growth, intake, and ruminal or health measurements.

Technical note: Infusion, sampling, and vacuum-assisted collection devices for use in ruminally cannulated calves

“…Rumen content pH changed from 5.62, measured when rumen contents were removed, to 5.60 when rumen contents were replaced in the rumen. Evacuated rumen contents represented about 4% (3.15/80 kg) of the calf's BW, which is slightly lower than what has been reported previously (5 to 8% of BW) in calves between 6 and 8 wk of age (Suárez et al, 2006;Kristensen et al, 2010;Yohe et al, 2015). This difference might be explained by the collection methods used.…”

Review: Utilization of yeast of Saccharomyces cerevisiae origin in artificially raised calves

“…Earlier, Tajima et al [85] showed that diet can have significant effect on rumen microbial composition using real-time PCR method. Diet manipulation through feed additives can further enhance the changes in the gut parameters [86]. There is varying information on the effect of SCY on the structural and functional development of the rumen.…”

Short communication: Initial evidence supporting existence of potential rumen epidermal stem and progenitor cells

“…Full-length rumen tissue (epidermis + dermis + muscle layers) from each heifer was fixed overnight in 10% neutral buffered formalin. Samples were then routinely processed, embedded in paraffin, cut to 5-μm thickness on a microtome, and mounted onto positively charged glass microscope slides (Yohe et al, 2015).…”

“…The top left panel shows that DNA synthesis in the rumen epidermis (bounded by white) occurs exclusively in the stratum basale [BrdU = light gray (green); DAPI nuclear counterstain = dark gray (blue)]. The top right panel is rumen tissue stained with Masson's trichrome provided for histological comparison (trichrome staining methods described in Yohe et al, 2015) rumen epidermis is maintained, how the rumen epidermis functions as a microbial barrier but also as a point of absorption for VFA, and how various nutrition programs affect ruminant nutrient utilization and feed efficiency.…”