||What drives calf growth?
||Sat 21 Apr 2012
What drives calf growth?
What is the single most influential factor affecting calf growth? What impact do various feeding programs have on the growth process? Calf expert Jim Quigley, PhD,author of CalfNotes.com, addresses these questions and more via a recently published research paper. The paper was published in the January issue of the Journal of Dairy Science and authored by H. Gale Bateman, PhD and his colleagues at the Nurture Research Center, Harrison, Ohio.
The research team evaluated what factors influenced body weight gain (calculated as average daily gain [ADG]) in calves fed varying nutritional programs, and evaluated the effects of calf health; environmental temperature; starting body weight and serum total protein (TP) of 993 calves. Each calf was two or three days old when they entered the study, and were monitored daily for eight weeks.
Among Quigley’s observations of the research results are:
· Calves had an average serum TP on arrival of 5.1 g/dL, with a range of 3.0 to 8.2 g/dL, indicating that colostrum delivery was marginal for consistently achieving passive transfer of immunity (achieved at a minimum serum TP of 5.2 g/dL).
· Over the 56-day study period, feed efficiency was improved by more days on milk (age at weaning), starter intake and milk protein crude protein.
· In the same evaluation period, feed efficiency was negatively affected by increasing number of day with scours and increasing initial body weight.
· Serum TP was not predictive of ADG prior to weaning, after weaning or over the entire eight-week period. Quigley theorizes that ADG may have been impacted more by illness (especially scours) that occurred because of low serum TP, than by actual serum TP numbers. In addition, calves that are housed under excellent management are less likely to be affected by scours, even if they have low serum TP.
· When calves were fed a moderate amount of commercial milk replacer (430 to 1,009 grams/day; average of 610 grams/day), intake of calf starter was the single most important factor affecting calf growth to eight weeks of age.
· Starter intake also affected feed efficiency and change in hip width through eight weeks of age.
Quigley advises more intensely managing starter intake, and monitoring intake levels as carefully as you do liquid feed sources. Read more of his comments on the subject