Feeding patterns of lactating cows of three different breeds fed hay, corn silage, and grass silage.

Feeding behavior of 35 lactating cows of three different breeds (Holstein-Friesian = HF, Simmental = SI, and Jersey = JER) was compared in the present study. The cows were kept in a loose housing system and fed hay, corn silage (CS) and grass silage (GS) ad lib. Within 7 consecutive days, 2918 meals were recorded and analyzed: 2503 meals were eaten during the light phase (0430-2200), and 57% of these diurnal meals consisted of only one feedstuff (43% hay, 9% CS, 5% GS). During the dark phase, only 23% of the 415 meals consisted of hay alone, but 16% of CS and 21% of GS alone. This circadian distribution showed no breed differences, yet meal patterns did: HF and SI cows ate 11 meals per day, and JER cows ate more than 13 meals/day. Meal size was 9.8MJ, 7.9MJ, and 5.8MJ for HF, SI, and JER cows, respectively. HF cows had the highest 24 h energy intake and JER cows the lowest, but the latter spent the most time feeding. During the light phase all three breeds obtained the most energy from hay, followed by CS and GS. In contrast, during the dark phase most energy was derived from GS, and hay contributed the least. A significant premeal correlation was observed for cows of all breeds, in particular during the time with the highest feeding activity (0800-1300). During the dark phase no premeal correlation could be detected; instead a significant postmeal correlation appeared, in particular in HF and SI cows.(ABSTRACT TRUNCATED AT 250 WORDS)