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

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 3AE5 kg DM baled grass silage daily, or 9AE5 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 prepartum 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 prepartum. 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.

Periparturient and early lactation performance and metabolism of replacement Holstein‐Friesian heifers out‐wintered on fodder beet or perennial ryegrass compared with winter housing

“…However, our findings are consistent with Keogh et al. (2009b), who reported that plasma BHB and glucose concentrations were not affected postpartum despite out‐wintering treatment diets continuing right up to parturition.…”

“…Milk yield (kg/d) during early lactation in Holstein‐Friesian animals in the current study when fed a high‐quality TMR was not affected by winter treatment, a finding consistent with that of similar studies that have examined the effect of out‐wintering systems for dairy cows destined for a low‐input, pasture‐based milk production system (Kennedy et al., ; Keogh et al., ,b). Despite the same diet being fed postpartum, heifers that had grazed fodder beet during the winter period had the lowest milk fat and the highest milk protein content.…”

“…Keogh et al. (2009b) reported a similar result in mature dairy cows, with a higher milk protein content in animals that had been out‐wintered on fodder beet or kale in comparison with those that were housed and fed grass silage. Dairy cows that have been fed fodder beet as part of a ration during lactation exhibit variable effects on milk constituents.…”

“…Similarly, Keogh et al. (2009b) using nonlactating pregnant dairy cows offered fodder beet in situ during the winter observed no increase in blood BHB.…”

“…A reduction in time spent eating has also been reported (Redbo et al., ), which may have an associated effect of reducing DMI and animal performance. However, previous research has reported little effect of out‐wintering on animal performance (Keogh, French, McGrath, Storey, & Mulligan, ,b; McCarrick & Drennan, ; O'Driscoll, Boyle, Hanlon, Buckley, & French, ) except when offered a diet exclusively of grazed perennial ryegrass (Keogh et al., 2009a). Much of the previous research regarding out‐wintering has been undertaken with beef cattle or mature dairy cows that are either kept at maintenance or to achieve low rates of liveweight (LW) gain (Keogh et al., 2009a; Morgan, McIlvaney, Dwyer, & Lawrence, ; O'Driscoll et al., ).…”