Effects of intake-based weaning and forage type on feeding behavior and growth of dairy calves fed by automated feeders

Abstract

The objective of this study was to assess the effects of intake-based weaning methods and forage type on feeding behavior and growth of dairy calves. Holstein dairy calves (n = 108), housed in 12 groups of 9, were randomly assigned to 1 of 3 weaning treatments: milk reduction based on age (wean-by-age), individual dry matter intake (DMI; wean-by-intake), or a combination of individual DMI and age (wean-by-combination). Groups of calves were alternately assigned to 1 of 2 forage treatments: grass hay or a silage-based total mix ration (TMR; n = 6 groups per treatment). Until 30 d of age, all calves were offered 12 L/d of whole milk. Starting on d 31, milk was gradually reduced by 25% of the individual's average milk intake. For wean-by-age calves (n = 31), the milk allowance remained stable until d 62 when milk was again reduced gradually until weaning at d 70. For wean-by-intake calves (n = 35), milk allowance was reduced by a further 25% once calves consumed on average 200, 600, and (finally) 1,150 g of dry matter (DM) per day of calf starter and forage. For wean-by-combination calves (n = 35), milk intake remained stable until calves consumed on average 200 g of DM/d, at which point milk was reduced linearly until weaning at d 70. If calves failed to reach DMI targets by d 62 (n = 10), milk was then reduced gradually until weaning at d 70. Of the 35 wean-by-intake calves, 27 met all 3 DMI targets (successful-intake), and 33 of the 35 calves in the wean-by-combination treatment met the 200 g of DM/d target (successful-combination). Successful-intake and successful-combination calves had greater final body weight (BW) at 12 wk of age than wean-by-age calves (123.7 vs. 122.3 vs. 117.7 ± 3.1 kg, respectively). During weaning, successful-intake calves ate more starter and consumed less milk than successful-combination and wean-by-age calves (starter:1.19 vs. 0.89 vs. 0.49 ± 0.07 kg of DM/d, respectively; milk: 2.7 vs. 4.2 vs. 5.9 ± 0.17 L/d, respectively). After weaning, successful-combination and successful-intake calves consumed similar amounts of starter; however, wean-by-age calves continued to consume less starter (2.85 vs. 2.78 vs. 2.44 ± 0.10 kg of DM/d, respectively). During weaning, hay and TMR calves ate similar amounts of forage, but hay calves consumed more starter (0.96 vs. 0.75 ± 0.07 kg of DM/d, respectively). After weaning, hay calves continued to consume more starter (2.88 vs. 2.50 ± 0.10 kg of DM/d, respectively), whereas TMR calves consumed more forage (0.33 vs. 0.15 ± 0.02 kg of DM/d, respectively). Hay calves had greater final BW at 84 d compared with TMR calves (124.0 vs. 119.0 ± 1.6 kg, respectively). These results show that the inclusion of a DMI target can improve starter intake and BW for calves that successfully wean, and that forage type can influence the transition onto solid feed. We also found that approximately 10% of calves failed to consume even 200 g of DM/d by 9 wk of age; more research is needed to better understand why some calves struggle to transition onto solid feed.

Growth Performance and Feed Intake Assessment of Italian Holstein Calves Fed a Hay-Based Total Mixed Ration: Preliminary Steps towards a Prediction Model

“…Indeed, during the first days of the trial, the average value was very low ( Figure 1 ), and only after 27 days did it reach and exceed 100 g. After this period, TMRI gradually increased as weaning approached ( Figure 1 ). A similar trend was observed by Welk et al [ 25 ] in calves fed with forage-based TMR. Some authors [ 26 ] have observed that early TMR administration to young livestock results in better ration consumption, reducing sorting against forage and for concentrates.…”

Calf Health, Feeding and Social Behaviours within Groups Fed on Automatic Milk Feeders

“…Each individual feed was limited to a maximum of 3 L by the AMF. This voluntary milk intake figure is in line with those found by other researchers [58][59][60]. A recent UK farmer survey indicated that 87.5% (189/216) of farmers only fed their calves twice daily, with 93.5% feeding ≤ 8 L of milk per day [61].…”

“…The overall mean number of refusal visits to the AMF was 4.9 (range of 0-46), and these increased over the weaning period even though a gradual step-down weaning program was used, which is in line with other studies [60,68,69]. Although solid feed intakes were not measured, the ADLG was maintained and even increased over the weaning period, suggesting that calves were likely to be transitioning well onto a solid feed diet, so hunger should not have influenced AMF visits.…”

“…Although solid feed intakes were not measured, the ADLG was maintained and even increased over the weaning period, suggesting that calves were likely to be transitioning well onto a solid feed diet, so hunger should not have influenced AMF visits. Others have suggested frustration as an explanation for unrewarded refusal visits during and following weaning [60], with the removal of nearad libitum access to milk resulting in a lack of expected milk rewards when a calf visits the AMF. There may also have been an impact on the difference in weaning schedule between group members, with some calves still eligible to receive milk, which may have encouraged fully weaned calves to visit the AMF as they observed other calves feeding.…”

Beef embryos in dairy cows: calfhood growth of Angus-sired calves from Holstein, Jersey, and crossbred beef dams

“…Preweaning growth of beef and beef cross calves born to Holstein dams (H ET and A × H) was similar to the results of Orellana Rivas et al (2022) who found ADG of 0.60 to 0.65 kg/d until 63 d among Holstein calves feed 0.65 to 0.76 kg of milk dry matter per day. However, growth performance was lesser than that reported by Zimpel et al (2021) who found ADG of 0.77 to 0.81 kg/d until d 56 among Holstein calves and Welk et al (2022) who found ADG of 0.70 to 0.88 kg/d until 70 d. The calves feed by Zimpel et al consumed ~0.35 kg more milk dry matter per day than was offered to the calves in the present study, and the calves fed by Welk et al were offered twice the volume of milk offered to the calves in the present study. Growth of the calves in the present study was likely limited by quantity of milk dry matter offered in the first 2 mo of life.…”