1759
An on-farm application of feed probiotics to increase total tract starch digestibility (TTSD) in high producing, lactating dairy cows
With the increased cost of grains and forages in the USA, dairy producers have turned their attention to the feed efficiency of milk production. Two reviews of starch digestibility in lactating dairy cows have suggested that over 50% of TTSD takes place in the lower digestive tract. Low on-farm starch digestibility contributes to reduced feed efficiency. Several researchers have demonstrated that measuring fecal starch is highly correlated to TTSD in lactating dairy cows. Our previous studies using a dairy feed probiotic (Probios® Complete, Chr. Hansen, Inc., Milwaukee, Wisconsin USA) demonstrated increases in TTSD, production performance, and feed efficiency in lactating dairy cows fed high starch + sugar diets (32% and 35%, respectively). To further validate this probiotic research, field trials were conducted to test a similar probiotic, Probios® Precise containing 3 strains of Enterococcus faecium and live yeast, on fecal starch on farm. Total mixed ration and fecal samples were collected from the same pen at 30-d day intervals for 90 d on 10 commercial dairy farms averaging 2,041 cows located in Wisconsin, Texas, New Mexico and Minnesota. Fresh floor fecal samples were collected from at least 20 cows per pen from cows less than 120 d-in-milk. Total mixed rations and fecal samples were analysed by Rock River Laboratories (Watertown, WI). Fecal components including starch (FS), protein, NDF, 120 h-indigestible NDF, fat, and ash (DM basis) were measured. Samples on d 0 were taken prior to adding Probios® Precise to each herd’s diet which averaged 23.7% starch (DM basis). Subsequent samples taken at 30, 60, and 90 d were analysed to measure the response from the probiotic treatment. The REG procedure of SAS was used to analyse the relationship between days fed Probios® Precise and FS. As days fed the probiotic increased, there was a reduction in FS (R2=0.31; P<0.001; 5.41, 3.95, 3.09, and 3.04%, respectively for d 0, 30, 60, and 90 sampling times). These results suggest that feeding the probiotic decreased FS confirming earlier trials that indicated certain feed probiotics decreased FS and increased TTSD in early lactation dairy cows. Thus, supplementing the dairy feed probiotics, Probios® Complete and Probios® Precise, can be a management tool to decrease FS, increase TTSD, with potential increase in feed efficiency.
Keywords: Dairy, Probiotics, Starch