Effects of pattern of concentrate allocation in the dry period and early lactation on feed intake and lactational performance in dairy cows

With the objective to study the effects of concentrate allocation strategy in the dry period and early lactation on feed intake and lactation performa nce, 96 dairy cows were used in a 2 x 3 factorial design experiment. The dr y cow feeding strategy was with [volatile fatty acid (VFA)-load] or without (control) a daily VFA-load generated by feeding concentrates and forage at different times of day. The three feeding strategies compared in early lac tation were separate feeding of silage ad libitum and restricted concentrat e with a daily increase in concentrate allowance of 0.3 kg (C-0.3) or 0.5 k g (C-0.5) up to a total of 10.2 kg/day or a complete diet. The postpartum d iets were designed to contain 50% of concentrates on a DM basis. The VFA-lo ad during the dry period did not improve postpartum feed intake and body we ight changes, whilst minor reductions in milk yield and milk composition we re observed during the first few weeks of lactation. The lack of positive e ffects suggests that the strategy had little effect on the rumen epithelium surface area and absorption capacity. Group C-0.5 ate less silage DM durin g weeks 2 to 4 than group C-0.3. The substitution rate between concentrate and silage was 0.94 during lactation weeks 2 to 4. with a higher concentrat e to roughage ratio in group C-0.5. Daily milk yield did not differ between C-0.5 and C-0.3 but group C-0.5 had a depressed milk fat percentage during lactation weeks 4 and 5. Group C-0.5 had the most marked changes in body w eight, probably due to differences in gut fill. Cows fed a complete diet ha d a significantly higher feed intake compared to cows fed concentrate and f orages separately, particularly during the first 3 weeks of lactation. Feed ing the complete diet improved energy corrected milk yield by 11% as a resu lt of higher milk yield during the first 4 weeks and a higher milk fat perc entage from week 6 of lactation. (C) 2001 Elsevier Science B.V. All rights reserved.