Influence of Residual Feed Intake and Cow Age on Dry Matter Intake Post-Weaning and Peak Lactation of Black Angus Cows

• Main Authors: Cory T. Parsons, Julia M. Dafoe, Samuel A. Wyffels, Timothy DelCurto, Darrin L. Boss
• Format: Article
• Language: English
• Published: MDPI AG 2021-06-01
• Series: Animals
• Subjects: beef cattle; cow age; dry matter intake; residual feed intake; stage of production
• Online Access: https://www.mdpi.com/2076-2615/11/6/1822

We evaluated heifer post-weaning residual feed intake (RFI) classification and cow age on dry matter intake (DMI) at two stages of production. Fifty-nine non-lactating, pregnant, (Study 1) and fifty-four lactating, non-pregnant (Study 2) commercial black Angus beef cows were grouped by age and RFI. Free-choice, hay pellets were fed in a GrowSafe feeding system. In Study 1, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect (<i>p</i> < 0.01) with an increase in DMI and intake rate with increasing cow age. In Study 2, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect (<i>p</i> < 0.02) with an increase in DMI and intake rate with increasing cow age. Milk production displayed a cow age × RFI interaction (<i>p</i> < 0.01) where both 5–6-year-old and 8–9-year-old low RFI cows produced more milk than high RFI cows. For both studies, intake and intake behavior were not influenced by RFI (<i>p</i> ≥ 0.16) or cow age × RFI interaction (<i>p</i> ≥ 0.21). In summary, heifer’s post-weaning RFI had minimal effects on beef cattle DMI or intake behavior, however, some differences were observed in milk production.