Starter-grain consumption is an important element in weaning calves successfully from the liquid ration. Failure to consume adequate levels of starter could lead to a postweaning issues such as a temporary growth slump, inadequate rumen development and even higher disease incidence.
To determine whether the physical formulation of starter grain rations can influence calves’ consumption habits, rumen fermentation dynamics and overall performance, a team of Spanish researchers (Marta Terre, Maria Devant and Alex Bach) conducted a series of three preference and performance studies:
Study 1 – 63 preweaned male Holstein calves were randomly assigned to one of three starter-grain groups.
- Group 1 – A pelleted starter feed containing wheat and soybean meal.
- Group 2 – A pelleted starter feed containing wheat and canola meal.
- Group 3 – A pelleted starter feed containing oats and soybean meal.
All three feeding groups also were offered chopped straw alongside their pelleted grain ration. Although previous studies have shown calves have a preference for wheat and soybean meal, no significant difference was observed between the three groups for intake, performance, or rumen fermentation parameters.
Study 2 – 37 crossbred (Holstein X White Belgian Blue) preweaned female calves were fed on a high plane of liquid nutrition and raised in individual hutches. Inside each hutch were 4 feed receptacles that contained starter feed in the same composition, but 4 different physical forms: (1) meal form; (2) pelleted form; (3) 70% pelleted form plus 20% whole corn and 10% barley; and (4) 70% pelleted form plus 20% steam-rolled corn and 10% steam-rolled barley.
During the first week of the study, calves had a preference for the pellets mixed with whole grains (3). After the first week, they preferred the pellets mixed with steam-rolled grain (4).
Study 3 – 63 preweaned male Holstein calves were randomly assigned to one of two starter feeds evaluated in Study 2.
- Group 1 – Pelleted feed mixed with whole corn and barley.
- Group 2 – Pelleted feed mixed with steam-rolled corn and barley.
Both groups also were offered free-choice, chopped barley straw in a separate pail in addition to starter grain. All were fed the same liquid ration on a high plane of nutrition. Feed intake and ruminal fluid were monitored, and feed refusals were evaluated to measure sorting behavior. Near the end of the milk-feeding period, calves fed steam-rolled grain sorted in favor of the grain versus pellets, while calves in the whole-grain group sorted in favor of the pellets. Calves offered the whole-grain mixture had greater rumen pH and tended to have lower total rumen volatile fatty acid concentrations. Despite these differences, there ultimately was no significant difference in performance between the two groups at the end of the study.
Overall, the researchers concluded:
(1) As a whole, preweaned calves preferred a starter-grain ration based on pellets mixed with steam-rolled grains.
(2) However, when calves could not choose their starter feed, pellets mixed with steam-rolled grains reduced concentrate intake and rumen pH compared to pellets mixed with whole grains, although performance was not impaired.
(3) Formulating starter concentrations based on calves’ sensory and physical preferences had little effect on overall performance.