SUPPLEMENTATION OF ZERO-GRAZED DAIRY-COWS WITH MOLASSED SUGAR-BEET PULP, MAIZE OR A CEREAL-RICH CONCENTRATE

Experiments were carried out to investigate the effects of different c arbohydrate sources on food intake, milk yield, composition of the mil k and its urea content. The experimental design was. a complete random ised block with four treatments per block. The treatments were: herbag e only (OS), herbage plus molassed sugar beet pulp (MSB), herbage plus maize (M) and herbage plus a mixture of oats, wheat and soybean meal (CON). The experiments were carried out on three replicates (E1, E2, E 3) with 20, 24 and 24 pure and cross-bred cows (Simmental, SimmentalXR ed Holstein Friesian). All cows were offered freshly cut herbage ad li bitum. Each experiment lasted 10 weeks, including a preliminary period of 2 weeks. Supplements were fed per block on an equal energy basis f or daily milk yields of 13-25 kg. Cows with a daily milk yield exceedi ng 25 kg received an additional supplement according to milk productio n and treatment (MSB, M and CON). Average (E1 to E3) total daily dry m atter (DM) intakes were 15.0, 17.8, 17.6 and 17.4 kg DM for Treatments OS, MSB, M and CON, respectively. Only the total DM intake between Tr eatment OS and the other treatments differed significantly (P < 0.05). Herbage DM intakes were in general highest for cows on OS (14.9 kg DM ), with cows on MSB, M and CON consuming on average (E1 to E3) 12.1, 1 2.6 and 11.8 kg herbage DM day(-1). The average daily milk yield (E1 t o E3) was 18.6, 20.8, 22.4, and 22.9 kg for OS to CON with only the di fference between Treatments M and CON being non-significant (P > 0.05) . The treatments had no significant effect on milk fat and protein con tents. The supplementation of herbage with maize (M) or a mixture of c ereals (CON) increased the lactose content compared with Treatments MS B (P < 0.05 only in E1) and OS (P < 0.05 only in E2). The highest inta ke of crude protein (CON) resulted in a significantly higher urea cont ent of the milk compared with Treatments MSB and M.