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

Abstract

AbstractSixty 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 3·5 kg DM baled grass silage daily, or 9·5 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.