Development of colonic microflora as assessed by pyrosequencing in dairy calves fed waste milk

• Published in: Journal of dairy science Vol. 95; no. 8; pp. 4519 - 4525
• Main Authors: Edrington, T.S., Dowd, S.E., Farrow, R.F., Hagevoort, G.R., Callaway, T.R., Anderson, R.C., Nisbet, D.J.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.08.2012; Elsevier
• Subjects: animal age; Animal productions; Animals; Animals, Newborn; bacteria; Bacteria - genetics; Bacteria - isolation & purification; bacterial diversity; Biological and medical sciences; calf feeding; Cattle - microbiology; colon; dairy calves; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Escherichia; feces; Feces - microbiology; feeds; Firmicutes; Food industries; food waste; Fundamental and applied biological sciences. Psychology; Gastrointestinal Tract - microbiology; intestinal microorganisms; milk; Milk - microbiology; Milk and cheese industries. Ice creams; nucleotide sequences; pasteurization; Pasteurization - standards; pasteurized milk; Principal Component Analysis; ribosomal DNA; Salmonella; Sequence Analysis, DNA; Shigella; species diversity; Terrestrial animal productions; Treponema; Vertebrates; waste milk; bacterial diversity; Salmonella; pasteurization; waste milk; Animal feeding; Dairy industry; Pasteurization; Dairy product; Development; Bacteria; Microflora; Enterobacteriaceae; Milk
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.2011-5119

The objective of the current study was to examine the effect of pasteurization of waste milk, used to feed dairy calves, on the bacterial diversity of their lower gut. Using 16S rDNA bacterial tag-encoded FLX amplicon pyrosequencing, fecal samples from dairy calves, ages 1wk to 6mo old and fed either pasteurized or nonpasteurized waste milk, were analyzed for bacterial diversity. Calves were maintained on 2 separate farms and, aside from how the waste milk was treated, were housed and cared for similarly. Fifteen calves were sampled from each age group (1, 2, and 4wk, and 2, 4, and 6mo of age; n=90 samples per milk treatment, 180 total samples) on each farm via rectal palpation and the samples shipped and frozen before analysis. In general, bacterial diversity, as represented by the total number of different species, was greater for the calves fed pasteurized waste milk at all ages (except 1wk of age) and increased with increasing age in both treatments. Proteobacteria, Bacteroidetes, and Firmicutes were the predominant phyla. Differences in phyla and class were observed among treatments and age of calf but with no consistent trends. Salmonella were detected in 9 out of 14 (64%) of the 1-wk-old calves fed nonpasteurized milk. Treponema, an important beneficial bacterium in cattle rumen, was more prevalent in the pasteurized waste milk-fed animals and became higher in the older animals from this group. Escherichia-Shigella were detected among treatments at all ages, and highest at 1wk of age, averaging approximately 21 and 20% of all bacteria for calves fed pasteurized and nonpasteurized waste milk, respectively, and decreasing as calves aged (2.6 and 1.3%). The consistent detection of Salmonella in the younger animals fed nonpasteurized milk and its absence in all other groups is an important finding related to this feeding practice.