Fernando Díaz
Synthetic flavors are additives used in the animal feed industry to enhance the smell and taste of feeds. The sense of taste in dairy cattle is well developed. They can recognize the five basic tastes of sweet, bitter, salty, sour, and umami. Therefore, identifying flavor preferences of dairy calves may help to stimulate and improve the consumption of calf starter.
Calf starter intake is essential in calf feeding programs. A meta-analysis carried out by Pennsylvania State University’s researchers reported that for each additional 100g/day of calf starter intake in the preweaning period, first-lactating cows produced 127.0 kg more milk, 8.4 kg more milk fat, and 4.0 kg more milk protein.
Two studies were conducted recently at the calf barn of The Pennsylvania State University Dairy Research and Teaching Center tested whether dairy calves have flavor preferences. The researchers Nedelkov et al. (2019) used cafeteria design experiments, defined as an experiment with a “brief exposure of animals to several plant species.” Calves were housed in individual hutches and fed a commercial calf starter.
In the first study, 12 weaned female Holstein calves (56–68 days of age) were used to test the flavors. The researchers removed the commercial calf starter and offered a choice of five experimental starters for five minutes: one unflavored and four flavored starters including different flavors (vanilla, milky, spicy/fenugreek, and red summer fruits). The inclusion rate of the flavors in the calf starter was 150-200 g/t. All five experimental starters were offered to each calf at the same time in five plastic bins placed in a wooden frame. The test was repeated 4 times with two-day intervals between tests.
The researchers observed that calves tended to consume more of the unflavored starter (58.5 g/test), less of the milky (35.4 g/test) and spicy/fenugreek (31.6 g/test) , and the least of red summer fruits (27.2 g/test) and vanilla (23.9 g/test) flavored starters. Interestingly, the average consumption rate was 27.8 g/minute, and there were no differences among starters.
In the second study, 12 weaned female Holstein calves (47–62 days of age) were offered a choice of four flavored starters with two flavors (combination of vanilla and fenugreek or a combination of milky and vanilla) at two inclusion rates (75 or 150 g/t). The flavored starters were offered every day for 60 min during the first 7 days and for 30 min during the last 7 days. The authors found an effect of flavor dose on feeding behavior. The starter flavored with vanilla-fenugreek at 75 g/t was consumed less (57.5 g/test) compared with the other flavored starters (average of 87.5 g/test).
In conclusion, synthetic flavors used in these experiments did not affect calf starter intake of weaned calves.
Reference
K. Nedelkov, M. T. Harper, A. Melgar, X. Chen, S. Räisänen, C. M. M. R. Martins, J. Faugeron, E. H. Wall, and A. N. Hristov. 2019. Acceptance of flavored concentrate premixes by young ruminants following a short-term exposure. J. Dairy Sci. 102:388–394.
