Residual feed intake divergence during the preweaning period is associated with unique hindgut microbiome and metabolome profiles in neonatal Holstein heifer calves

• DOI: 10.1186/s40104-019-0406-x
• Publication Date: 2020-01-20T13:02:44Z
• Authors: Ahmed Elolimy; Abdulrahman Alharthi; Mohamed Zeineldin; Claudia Parys; Juan J. Loor
• Keywords: Metabolome; Hindgut; Residual feed intake; Animal Feed; Starter; Milking

Abstract Background Recent studies underscored that divergence in residual feed intake (RFI) mature beef and dairy cattle is associated with changes ruminal microbiome metabolome profiles which may contribute, at least part, to better efficiency. Because the rumen neonatal calves during preweaning period underdeveloped until close weaning, they rely on hindgut microbial fermentation breakdown undigested diet components. This leads production of key metabolites such as volatile fatty acids (VFA), amino acids, vitamins could potentially be absorbed hind-gut help drive growth development. Whether RFI communities largely unknown. Therefore, objective current study was determine differences Holstein heifer retrospectively-grouped based efficiency most-efficient (M-eff) or least-efficient (L-eff) using period. Methods Twenty-six received 3.8 L first-milking colostrum from their respective dams within 6 h after birth. Calves were housed individual outdoor hutches bedded straw, fed twice daily a milk replacer, had ad libitum access starter grain mix birth weaning 42 d age. classified into M-eff [ n = 13; coefficient − 5.72 ± 0.94 kg DMI (milk replacer + grain)/d] L-eff 5.61 linear regression model including combined DMI, average gain (ADG), metabolic body weight (MBW). A deep sterile rectal swab exposed only rectum collected immediately before feeding (i.e., 0), fecal samples 14, 28, (prior weaning) for untargeted analyses 16S rRNA gene sequencing LC-MS. Microbiome data analyzed QIIME 2 platform MetaboAnalyst 4.0 pipeline. Results No ( P > 0.05) measurements (BW), length (BL), hip height (HH), width (HW), wither (WH) detected between preweaning. Although did not differ groups, compared L-eff, heifers lower < 0.01) 18 age, whereas no ADG, cumulative BWG, observed groups through first age indicated greater capacity energy-generating substrates (butyrate propionate) essential nutrients (vitamins acids) estimated Conclusion Despite consuming approximately 54.6% less solid (cumulative intake, 10.90 vs. 19.98 1.66 kg) microbiome-metabolome might have helped them maintain same level heifers.