Effect of three forages and two forage allowances offered to pregnant dry dairy cows in winter on periparturient performance and milk yield in early lactation

Sixty multiparous, Holstein-Friesian pregnant dry dairy cows were allocated to three forage treatments (n = 20; fodder beet, kale or grass silage) at two feeding allowances (n = 30; high and low) for 70 (s.e. of mean, 16) d before parturition. Cows offered the high feeding allowance were offered 9 kg of dry matter (DM) of kale or fodder beet grazed in situ plus 5 kg DM of baled grass silage daily or clamp grass silage ad libitum offered indoors. Cows offered the low feeding allowance were offered 6 kg DM of kale or fodder beet grazed in situ plus 3 center dot 5 kg DM baled grass silage daily, or 9 center dot 5 kg DM of clamp grass silage daily offered indoors. After calving, all cows received a daily allowance of 14 kg DM perennial ryegrass herbage at pasture plus 4 kg concentrate cow(-1) for the first 35 d of lactation. Cows offered grass silage had a greater increase in body condition score pre-partum compared to those offered kale or fodder beet. Cows offered fodder beet pre-partum had a greater milk solid and solids-corrected milk yield in the first 35 d of lactation than those offered kale and grass silage pre-partum. Offering fodder beet and kale pre-partum increased plasma non-esterified fatty acid concentrations pre-partum relative to offering grass silage. Offering kale pre-partum resulted in higher insulin-like growth factor-1 concentration post-partum but lower plasma copper concentration pre-partum and at calving than kale or grass silage. Offering the higher forage allowance pre-partum resulted in a higher plasma calcium concentration at calving and higher plasma non-esterified fatty acid concentration post-partum.