Ingestive behavior of dairy cows in annual ryegrass pasture, fed with different proteic sources

The effect of the replacement of soybean meal in the ration with controlled grazing of white clover (Trifolium repens L.) on the ingestive behavior of cows of the holstein breed grazing on annual ryegrass (Lolium multiflorum Lam.) was studied. Two groups of animals with an average of 20 cows grouped by production, lactation period and body weight were used in a randomized block experimental design. One group received 3kg from energy supplement daily and had controlled access to the white clover pasture for approximately 2.5 hours (TB); the other received the same supplement, added of a quantity of protein equivalent to daily intake in previous treatment via white clover, in the form of soybean meal (FS). For behavior assessment the observation and recording of the rhythm of activity of the animals, during the grazing period in ryegrass for two consecutive days, fortnightly was done. The longest grazing time in minutes (min), 212.00 versus 194.24min day(-1), and bite frequency (bite), 67.78 versus 64.09 bite min(-1), between the animals from treatment FS, when compared to TB was observed. There was no difference in the intake of ryegrass between the treatments, with values of 3.65 and 4.11kg cow(-1) day(-1) of dry matter for TB and FS, respectively, suggesting adequate adaptation of the animals in the two situations studied.