Effects of milk replacer feeding rate and long-term antibiotic inclusion in milk replacer on performance and nutrient digestibility of Holstein dairy calves up to 4 months of age

Abstract

The objectives of this study were to evaluate calf performance and diet digestibility when feeding a milk replacer (MR; 25% crude protein, 18% fat, dry matter basis) at a moderate (MOD) and high (HI) rate, along with MOD with neomycin-oxytetracycline inclusion (1.43 each g/kg; NTMOD). Male Holstein calves (n = 48; 45 ± 1.0 kg of body weight; 3 to 4 d of age) were housed in individual pens for 56 d. All calves were initially fed 0.66 kg of dry matter from MR for the first p.m. and following a.m. feeding, then randomly assigned to 1 of 2 feeding programs: (1) 0.66 kg of dry matter/d for first 39 d divided into 2 equal a.m. and p.m. meals and 0.33 kg for 3 d fed once daily in the a.m. feeding only (MOD, NTMOD); (2) 0.85 kg of dry matter/d for the first 4 d divided into 2 equal a.m. and p.m. meals, 1.07 kg of dry matter/d for the next 31 d divided into 2 equal a.m. and p.m. meals, and 0.48 kg for 7 d fed once daily in the a.m. feeding only (HI). Calves were fed a textured starter containing whole grains (20% crude protein, 43% starch, dry matter basis). Fecal samples were collected for 5 individual calves per treatment between d 47 to 51 to estimate digestibility. Calves were moved into groups by treatment (4 calves/pen) at 56 d and fed the same starter blended with 5% hay until d 112. Data were analyzed as a completely randomized design with repeated measures when applicable using mixed models. Milk replacer dry matter intake averaged 27.4 kg for MOD and NTMOD and 40.3 kg for HI per calf. Preweaning starter intake was less for calves fed HI versus MOD. Preweaning calf BCS change was greater for calves fed HI versus MOD. Preweaning medical treatment days were fewer for calves fed NTMOD versus MOD. Postweaning starter intake was less for calves fed HI versus MOD. Postweaning average daily gain was less for calves fed NTMOD versus MOD. Over the 56-d nursery trial, calves fed HI had less starter intake than calves fed MOD. Digestibility of dry matter, organic matter, acid detergent fiber, and neutral detergent fiber were greater for calves fed MOD versus NTMOD or HI during d 47 to 51 postweaning. Additionally, digestibility of fat was greater for calves fed MOD versus HI. During d 56 to 112, hip width change was greater for calves fed MOD versus NTMOD or HI. Over 0 to 112 d, body weight gain was 100, 98, and 102 kg, whereas hip width change was 10.2, 9.0, and 9.2 cm for calves fed MOD, NTMOD, and HI, respectively. Any preweaning improvements from feeding NTMOD or HI over MOD were lost during the postweaning period, which could be partially explained by reductions in diet digestibility.

Effect of amount of milk replacer fed and the processing of corn in starter on growth performance, nutrient digestibility, and rumen and fecal fibrolytic bacteria of dairy calves

“…Similar findings to the present study regarding MR feeding rate (LO vs. HI) and its effect on preweaning CS intake (Hill et al, 2016a;Dennis et al, 2018Dennis et al, , 2019, BW (Jasper and Weary, 2002;Khan et al, 2011;Rosenberger et al, 2017) and fiber apparent totaltract digestibility (Hill et al, 2016a;Dennis et al, 2018) have been reported. Feeding high rates of MR to calves should provide enough nutrients to sustain satiety largely on MR alone, thus decreasing CS intake compared with calves fed MR at a low rate, as was shown in the present study and previous reports (Hill et al, 2016a;Dennis et al, 2018Dennis et al, , 2019. The higher rate of MR feeding also resulted in higher BW until wk 7 from the greater ME intake compared with calves fed MR at a lower rate (Rosenberger et al, 2017).…”

“…In addition, MR has a higher digestibility compared with CS, therefore contributing more energy toward growth compared with CS. Studies reporting NDF and ADF digestibility have consistently noted that calves fed higher rates of MR have lower NDF and ADF digestibility at various weeks of life (Chapman et al, 2016;Dennis et al, 2018Dennis et al, , 2019. In our study, poor fiber apparent total-tract digestibility was carried over into the grower period (6 wk after weaning) by calves fed HI, as reported previously (Hill et al, 2016a).…”

Effects of milk replacer feeding rates on growth performance of Holstein dairy calves to 4 months of age, evaluated via a meta-analytical approach

“…For calves fed MOD, MR was halved into a.m. and p.m. feedings for 35 to 39 d, followed by a.m. feeding of half of the previous MR amount for 3 to 7 d (Table 2). For calves fed HI, MR feeding regimens were more variable among the trials in 10 studies, of which there were constant (Hu et al, 2019), step-up (Hill et al, 2016a;Dennis et al, 2017Dennis et al, , 2018aDennis et al, , and 2019Quigley et al, 2018 and2019a), or step-up and step-down (Dennis et al, 2018b) MR feeding programs pre-weaning. In general, calves fed HI consumed equal amounts of MR twice daily (a.m. and p.m. feeding) for a period of 35 to 44 d, followed by a.m. feeding of half of the previous MR amount for 5 to 7 d (Table 2).…”

The effect of neomycin inclusion in milk replacer on the health, growth, and performance of male Holstein calves during preweaning

“…These results are consistent with Heinrichs et al (2003), who also found that neomycin, in combination with oxytetracycline, did not serve as promoters of frame size development, BW, or ADG. Dennis et al (2019) also found that a combination of neomycin and oxytetracycline in MR (1.43 g/kg of MR each, equivalent to 11.43-20.17 mg/ kg of BW per day each) for 42 d did not improve BW gain, although it did improve frame size development. However, Quigley et al (1997) found that oral administration of neomycin with oxytetracycline (2.7-3.3 mg/ kg of BW per day of neomycin and 1.3-1.7 mg/kg of BW per day of oxytetracycline for 26 d) in MR improved BW gain.…”

“…Some studies have shown that oral antimicrobials, including neomycin, are effective in reducing diarrhea occurrence in calves (Quigley et al, 1997;Heinrichs et al, 2003), and others associate oral antimicrobial usage with increased diarrhea incidence and severity (Shull and Frederick, 1978;Mero et al, 1985;Berge et al, 2009b). The effects of antimicrobial usage on growth performance variables are also conflicting, with one study showing improved calf growth (Quigley et al, 1997) and others showing no benefit (Heinrichs et al, 2003;Dennis et al, 2019). Several factors may contribute to these mixed results, including the use of different treatment antimicrobials, as well as varying dosages and durations used between studies.…”