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Effects of Feeding Rate and Concentrations of Protein and Fat of Milk Replacers Fed to Neonatal Calves
The Professional Animal Scientist 22 (2006):374–381
Effects of Feeding Rate and Concentrations of Protein and Fat of Milk Replacers Fed to Neonatal Calves T. M. HILL,1 J. M. ALDRICH, PAS, R. L. SCHLOTTERBECK, and H. G. BATEMAN,II Akey, Nutrition and Research Center, Lewisburg, OH 45338
Abstract Three trials were conducted to examine the effects of feeding rate and concentration of CP and fat in the milk replacer (MR) on calf performance. In all trials, Holstein bull calves (41 to 42 kg average initial BW; less than 7-d old) were randomly assigned to MR treatments and fed fixed amounts of MR with free-choice starter and water for 6 wk. Calves were fed starter and water after 6 wk. Calves were weighed initially and weekly. Starter intake was measured and fecal scores and medical treatments recorded daily. In all trials, a conventional 20% CP, 20% fat MR fed at 0.45 kg daily served as the control treatment. Trial 1 included CP concentrations ranging from 22 to 28% in MR fed at 0.68 kg daily. Trial 2 included fat concentrations from 11 to 17% in MR fed at 0.68 kg daily. Calves were weaned at 42 d and measurements were recorded through 56 d. In each trial, calves fed the control MR gained the slowest. When 0.68 kg daily of a 13% fat MR was fed with CP concentrations from 22 to 28%, BW gains increased linearly (optimum of 26%) and starter intake was no different
1
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from the control. When 0.68 kg daily of a 24% CP MR was fed with fat concentrations between 11 and 17%, BW gains increased linearly and starter intake was not different from the control. Trial 3 was conducted with MR of 26 and 28% CP and 17 and 20% fat fed at 0.68 or 0.77 kg daily. Calf BW gains did not differ among MR fed at 0.68 and 0.77 kg daily. Performance data from these trials indicate that a MR fed at 0.68 kg daily should contain approximately 26% CP and 17% fat, with no results suggesting that starter intake or efficiency would be reduced or scouring would be increased compared to a conventional 20% CP, 20% fat MR fed at 0.45 kg. Key words: calves, protein, fat, growth
Introduction There is considerable discussion in our current dairy industry regarding feeding high protein milk replacers (MR) to neonatal calves. Diaz et al. (2001) fed calves a 30% milk CP, 20% fat MR diet (with no dry starter feed) at varying rates up to a maximum consumption of 2.5 kg of dry milk powder daily and reported increasing daily BW gains and feed efficiencies with increasing intake of powder, suggesting that neonatal
calves should be fed for faster rates of BW gain and require more CP than typical of industry practices. This is consistent with protein requirements outlined in Chapter 10 of the dairy NRC (2001) and subsequent research of Blome et al. (2003). Brown et al. (2005) and Quigley et al. (2006) reported improved BW gains, reduced starter intakes, and better feed efficiencies when calves were fed approximately 0.9 kg of 28% CP MR, but Hess et al. (2001) reported similar BW gains and starter intakes with lesser feed efficiencies when 0.69 kg of a 30% CP MR was fed compared to feeding 0.38 to 0.5 kg of a 20% CP, 20% fat MR. All reported increased sickness in calves receiving a greater rate of MR. We observed no change in BW gain and efficiency with decreased starter intake and increased sickness in 2 trials in which we fed 1.13 and 1.36 kg of a 28% CP, 20% fat MR (Hill et al., 2006). However, we observed 55% faster BW gains and more desirable efficiency with moderate decreases in starter intake (11%) and increases in medical treatments (27%) when we fed 0.68 kg of a 28% CP, 20% fat MR in a third trial compared to feeding 0.45 kg of a 20% CP, 20% fat MR. The moderate feeding rate of 0.68 kg of a 28% CP, 20% fat MR appeared more promising
Feeding Rate and Composition of Milk Replacers
than greater feeding rates of more than 1 kg daily, yet starter intake was slightly reduced and medical treatments slightly increased (Hill et al., 2006). The overall objective of these trials was to identify a MR program fed with starter that would yield faster growth (with minimum health and management challenges) than are currently achieved in the industry with conventional MR fed at approximately 0.45 kg daily. The objectives of the first 2 research trials were to feed a moderate rate (0.68 kg daily) of a MR containing various CP (22 to 28%) and fat (11 to 17%) concentrations with starter feed offered to determine their effects on BW gain, starter intake, and calf health. The objective of the third trial was to feed a more narrow range of protein and fat concentrations in MR fed at 0.68 and 0.77 kg daily to determine their effects on BW gain, starter intake and calf health.
Materials and Methods Trial 1. Fifty calves were fed 1 of 5 treatments. Treatment 1A was a control 20% CP, 20% fat MR fed at 0.45 kg daily. The other 4 MR treatments contained 13% fat, were fed at 0.68 kg daily, and were 1B) 22% CP, 1C) 24% CP, 1D) 26% CP, and 1E) 28% CP. Trial 2. Forty-eight calves were fed 1 of 4 treatments. Treatment 2A was a control 20% CP, 20% fat MR fed at 0.45 kg daily. The other 3 MR treatments contained 24% CP, were fed at 0.68 kg daily, and were 2B) 11% fat, 2C) 14% fat, and 2D) 17% fat. Trial 3. Seventy-two calves were fed 1 of 6 MR treatments. Treatment 3A was a control 20% CP, 20% fat MR fed at 0.45 kg daily. The other 5 treatments were 3B) 0.68 kg daily of a 26% CP, 17% fat MR, 3C) 0.77 kg daily of a 26% CP, 17% fat MR, 3D) 0.68 kg daily of a 28% CP, 20% fat MR, 3E) 0.68 kg daily of a 28% CP, 17% fat MR, and 3F) 0.68 kg daily of a 26% CP, 20% fat MR.
Feeds. All calves received a common pelleted starter formulated (asfed basis) to be 18% CP, 0.7% Ca, and 0.5% P and contain 65% corn, 23% soybean meal, 5% wheat midds, 2.5% of a protein blend (73% CP, asfed basis; Papillon Ag. Products, Inc., Easton, MD), macrominerals, trace minerals, vitamins, and decoquinate (0.025 mg/kg). The formulas for the MR are shown in Table 1. The feeds were assayed (AOAC, 1996) for CP, fat, ash, Ca, and P (Tables 2 and 3). Animals, Preventative Health Management, and Measurements. Holstein bull calves were received from multiple dairies at less than 1 wk of age after a 10-hour transit and immediately fed 113 g of electrolyte (80% dextrose, 6% Na, 1% K) reconstituted to 2 L with warm water. Approximately 12 h later the calves were weighed and randomly assigned to treatment by weight. After blood was sampled intravenously for serum protein determination via a refractometer, calves were offered their respective MR treatment. Calves were initially fed 0.23 kg of MR reconstituted to 1.9 L with warm water twice daily at approximately 12-h intervals. Calves that were to be fed 0.68 or 0.77 kg of MR daily were initially fed 0.45 kg daily and then increased to 0.68 or 0.77 kg of MR on d 3. All MR were reconstituted at the rate of 0.12 kg MR powder/L of liquid volume. Calves were weaned by feeding 50% of the daily MR in the a.m. only for 2 d. In all trials, calves were weaned at 6 wk of age and measurements were recorded to 8 wk of age. Calves were weighed initially and weekly thereafter midway between a.m. and p.m. feedings. Initial BW were 42 ± 2 kg for Trials 1 and 2 and 41 ± 2 kg for Trial 3. Dry starter feed was offered initially on d 3 and refused and fresh feed were weighed daily. Fecal scores were assigned daily based on a 1 to 5 system (1 being normal, thick in consistency; 2 being normal, but less thick; 3 being abnormally thin but not watery; 4 being watery; 5 being watery with abnormal coloring). Body condition
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was scored and hip widths measured at time of initial weighing and at 2, 4, 6, and 8 wk thereafter. Body condition score (BCS) was based on a 1 to 5 system using 0.25 unit increments with 1 being emaciated and 5 being obese (Wildman et al., 1982). Scores were based on changes around the vertical and transverse processes of the spine as palpated by one experienced technician and ranged from 1.75 to 3.5. Vaccines and health protocols were based on the recommendations of a veterinarian. Calves received an intranasal tissue-sensitive respiratory disease vaccine (TSV-2, Pfizer, Exton, PA) and subcutaneous injections of vitamins A, D, and E (Vital E-A + D, Schering-Plough Animal Health, Union, NJ) and Se (MU-SE, ScheringPlough Animal Health, Union, NJ) upon arrival. Calves received an intramuscular respiratory disease vaccine (Bovashield Gold 5, Pfizer, Exton, PA) at d 7 and again at d 28. At d 14 they received an intramuscular vaccine for types C and D clostridium (Ultra Choice 7, Pfizer, Exton, PA). A pasturella vaccine (Presponse HM, Fort Dodge, Fort Dodge, IA) was administered intramuscularly on d 28 and 42. Calves were castrated and dehorned on d 36. Animals that required medication for digestive (subcutaneous ceftiofur sodium, Naxcel, Pharmacia & Upjohn, Kalamazoo, MI) or navel (subcutaneous penicillin G procaine, Agri-Cillin, AgriLabs, St. Joseph, MO) infections were treated per veterinary recommendation and treatments were recorded daily. Digestive infections were diagnosed based on rectal temperatures (>39.5°C), lack of vitality, and fecal scores > 2. Over 95% of the medical treatments were because of digestive upsets (scouring) with the remainder for navel infections that were not included in the reported treatments. Calves were housed a curtain-sided, naturally ventilated barn with no added heat in 1.2 m by 2.4 m pens bedded with straw. Calves had access to clean, fresh water at all times. All animals were cared for by acceptable
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Table 1. Ingredient composition of milk replacers used in Trials 1, 2, and 3 (as-fed basis). Milk replacera Item Trial Target % CP Target % fat DE, Mcal/kg Rate fed, kg Ingredient, % Whey Dry fat, 60% WPC,b 34% WPC, 45% Premixc Decoquinated Dicalcium P
A
B
C
D
E
B
C
D
B
C
D
E
F
All 20 20 4.96 0.45
1 22 13 4.64 0.68
1 24 13 4.67 0.68
1 26 13 4.70 0.68
1 28 13 4.74 0.68
2 24 11 4.57 0.68
2 24 14 4.72 0.68
2 24 17 4.88 0.68
3 26 17 4.91 0.68
3 26 17 4.91 0.77
3 28 20 5.10 0.68
3 28 17 4.95 0.68
3 26 20 5.07 0.68
34.5 28.6 18.9 15.5 1.3 1.0 0.2
41.9 16.5 24.4 15.5 1.0 0.7 —
33.9 16.2 32.7 15.5 1.0 0.7 —
25.9 15.9 41.0 15.5 1.0 0.7 —
17.8 15.7 49.3 15.5 1.0 0.7 —
37.9 12.9 32.0 15.5 1.0 0.7 —
31.9 17.9 33.0 15.5 1.0 0.7 —
25.8 22.9 34.1 15.5 1.0 0.7 —
17.8 22.6 42.4 15.5 1.0 0.7 —
17.9 22.6 42.4 15.5 1.0 0.6 —
3.9 27.4 51.5 15.5 1.0 0.7 —
9.8 22.3 50.7 15.5 1.0 0.7 v
11.8 27.6 43.4 15.5 1.0 0.7 —
a
Milk replacers B and C in Trial 3 were made as one batch. Whey protein concentrate. c Labeled concentrations of vitamin, mineral premix were: 0.03 g selenium/kg, 7,700 KIU vitamin A/kg. d Concentration: 5 g/kg; Alpharma, Inc., Fort Lee, NJ. b
practices as described in the Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (FASS, 1999). Statistical Analysis. Data were analyzed by trial as a completely randomized block design using the GLM procedure of SAS (SAS Inst., Inc., Cary, NC). Effects of block (initial BW) and diet were considered random and fixed effects, respectively. Starter intake, fecal score, and medical treatment data were first pooled by week then analyzed. There was no sub-sampling and data reported are least square means for the experimental unit (calf). In Trials 1 and 2, if differences among the treatment diets were significant (P < 0.1), an orthogonal polynomial contrast for level of MR fed (0.45 vs. 0.68 kg daily) and orthogonal polynomial contrasts for linear and quadratic effects among the treatment diets fed at the 0.68 kg daily level were conducted to further characterize differences. In Trial 3, if differences among the treatment diets were significant (P < 0.1), treatment means were separated using the Student-Newman-Keuls test in SAS (SAS Inst., Inc.). In cases where P < 0.1, dif-
trol), 22, 24, 26, and 28% CP MR, respectively. All calves consumed the MR offered. Daily BW gain (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) were improved from 0 to 42 d when 0.68 kg of MR was fed compared to when 0.45 kg of MR was fed (Table 4). For the individual weeks of 2, 3, 4, 5, and 6, BW gain
ferences among fixed effects were considered significant.
Results and Discussion Trial 1. Serum protein concentrations did not differ (P > 0.1; 5.5 ± 0.3 mg/dL) for calves fed the 20 (con-
Table 2. Analyzed nutrient content of milk replacers and starter used in Trials 1 and 2 (as-fed basis). Milk replacera A Trial Target % CP Target % fat Rate fed, kg/d Analysis Moisture, % CP, % Fat, % Ash, % Ca, % P, % a
B
C
D
E
B
C
D
Starter
1, 2 1 1 1 1 2 2 2 20 22 24 26 28 24 24 24 20 13 13 13 13 11 14 17 0.45 0.68 0.68 0.68 0.68 0.68 0.68 0.68
1, 2 18 — —
3.3 3.3 3.4 3.4 3.2 3.5 3.3 3.3 20.1 22.1 24.1 26.0 28.1 24.0 24.1 24.2 20.2 13.2 13.0 13.1 13.2 11.3 14.2 17.1 6.5 6.3 6.2 6.0 5.9 6.3 6.2 6.3 0.76 0.77 0.80 0.82 0.86 0.82 0.81 0.82 0.61 0.62 0.62 0.64 0.65 0.62 0.63 0.61
11.8 18.0 3.7 4.9 0.88 0.53
Milk replacer A and the starter used in Trials 1 and 2 were made as one batch prior to Trial 1. Starter calculated to 2.95 Mcal digestible energy/kg.
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Feeding Rate and Composition of Milk Replacers
Table 3. Analyzed nutrient content of milk replacers and starter used in Trial 3 (as-fed basis). Milk replacera Item Target % CP Target % fat Rate fed, kg/d Analysis Moisture, % CP, % Fat, % Ash, % Ca, % P, %
A
B
C
D
E
F
Starter
20 20 0.45
26 17 0.68
26 17 0.77
28 20 0.68
28 17 0.68
26 20 0.68
18 — —
3.3 20.1 20.2 6.6 0.77 0.60
3.2 26.0 17.2 5.8 0.84 0.65
3.3 26.3 17.0 5.7 0.85 0.65
3.3 28.1 19.9 5.5 0.84 0.64
3.2 28.1 17.0 5.6 0.85 0.66
3.3 26.0 20.0 5.6 0.85 0.65
12.0 18.0 3.8 5.1 0.90 0.52
a
Milk replacers B and C were made as one batch but analyzed separately. Starter calculated to 2.95 Mcal of digestible energy/kg.
was improved (P < 0.1) when 0.68 kg of MR was fed compared to when
0.45 kg of MR was fed. Within the calves fed 0.68 kg of MR, BW gain
was increased quadratically (P < 0.05) from 0 to 42 d with increasing level of CP. Within the calves fed 0.68 kg of MR, daily starter intake (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) increased in a linear manner from 0 to 42 d with increasing level of CP. Within the calves fed 0.68 kg of MR for the individual weeks of 2, 3, 4, 5, and 6, BW gains and starter intake increased in a linear manner (P < 0.1) with increasing level of CP; however, BW gain was maximized at 26% CP. Feed efficiencies (gain per feed) did not differ (P > 0.1) from 0 to 42 d and were 0.49, 0.50, 0.51, 0.58, and 0.51 for calves fed the 20 (control), 22, 24, 26, and 28% CP MR, respectively. Gain of BW (0.89 kg/d), starter intake (1.03 kg/d), hip width change (1.12 cm), BCS change (1.13), and average fecal score (1.13) did not differ (P > 0.1) in the 14 d post-weaning.
Table 4. Effect of feeding a 20% CP, 20% fat milk replacer at 0.45 kg daily compared to feeding a 13% fat milk replacer at 0.68 kg daily that contained 22, 24, 26, or 28% CP (0 to 42 d of age; Trial 1). Milk replacer Item CP, % Rate fed, kg/d No. of calves Initial calf BW, kg ADG, kg/d Average starter intake, kg/d Average CP intake, kg/d Average fat intake, kg/d Average DE intake, Mcal/d Gain/feed efficiencyb Total medical treatments Average fecal scorec Abnormal fecal score daysc Days with fecal score = 2 Condition score changed Hip width change, cm
A
B
C
D
E
SE
Significancea
20 0.45 10 42.1 0.46 0.50 0.18 0.11 3.71 0.49 6.0 1.7 2.9 15.8 1.0 2.7
22 0.68 10 42.8 0.50 0.38 0.22 0.10 4.28 0.50 5.2 1.8 2.6 21.2 1.1 2.8
24 0.68 10 41.7 0.54 0.43 0.24 0.11 4.44 0.51 6.6 1.8 3.3 21.0 1.2 2.9
26 0.68 10 42.3 0.63 0.46 0.26 0.11 4.55 0.58 5.0 1.7 2.4 19.2 1.3 3.1
28 0.68 10 42.5 0.63 0.62 0.30 0.11 5.05 0.51 6.8 1.8 3.3 21.1 1.3 3.2
— — — 4.1 0.04 0.03 0.01 0.01 0.29 0.03 0.92 0.06 0.44 2.2 0.11 0.22
— — — — CO, Q L CO, L — CO, l — — — — co co, l co, l
CO = control vs. other MR (P < 0.05); co = control vs. other MR (P < 0.1); Q = quadratic effect of level of protein in 13% fat MR (P < 0.05); L = linear effect of level of protein in 13% fat MR (P < 0.05); l = linear effect of level of protein in 13% fat MR (P < 0.1). b Gain divided by starter plus milk replacer intake. Milk replacer intake from 0 to 6 wk when it was fed averaged 0.44 kg for the group fed 0.45 kg MR and 0.65 kg for the group fed 0.68 kg MR. c Fecal scores: 1 = normal, thick in consistency; 2 = normal, but less thick; 3 = abnormally thin but not watery; 4 = watery; 5 = watery with abnormal coloring. Abnormal fecal scores were days with scores > 2. d 1 to 5 system with 1 = emaciated and 5 = obese. a
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Table 5. Effect of feeding a 20% CP, 20% fat milk replacer at 0.45 kg daily or feeding a 24% CP milk replacer at 0.68 kg daily that contained 11, 14, or 17% fat (0 to 42 d of age; Trial 2). Milk replacer Item Fat, % Rate fed, kg/d No. of calves Initial calf BW, kg ADG, kg/d Average starter intake, kg/d Average CP intake, kg/d Average fat intake, kg/d Average DE intake, Mcal/d Gain/feed efficiencyb Total medical treatments Average fecal scorec Abnormal fecal score daysc Days with fecal score = 2 Condition score changed Hip width change, cm
A
B
C
D
SE
Significancea
20 0.45 12 41.8 0.40 0.39 0.16 0.11 3.38 0.48 5.9 1.6 2.9 16.1 0.5 2.0
11 0.68 12 42.0 0.54 0.33 0.22 0.09 4.08 0.56 6.5 1.9 3.2 22.2 0.6 2.3
14 0.68 12 42.4 0.59 0.39 0.23 0.11 4.36 0.58 6.4 1.7 3.1 21.9 0.7 2.6
17 0.68 12 42.1 0.63 0.41 0.24 0.13 4.53 0.61 6.2 1.6 3.0 21.9 0.9 2.8
— — — 4.0 0.04 0.03 0.01 0.01 0.31 0.03 0.42 0.05 0.23 22.1 0.09 0.12
— — — — N, L L CO L CO, l n l n, l l n n, l n, l
N = control vs. other MR (P < 0.05); n = control vs. other MR (P < 0.1); L = linear effect of level of protein in 13% fat MR (P < 0.05); l = linear effect of level of protein in 13% fat MR (P < 0.1). b Gain divided by starter plus milk replacer intake. Milk replacer intake from 0 to 6 wk when it was fed averaged 0.44 kg for the group fed 0.45 kg MR and 0.65 kg for the group fed 0.68 kg MR. c Fecal scores: 1 = normal, thick in consistency; 2 = normal, but less thick; 3 = abnormally thin but not watery; 4 = watery; 5 = watery with abnormal coloring. Abnormal fecal scores were days with scores > 2. d 1 to 5 system with 1 = emaciated and 5 = obese. a
Trial 2. Serum protein concentrations did not differ (P > 0.1, 5.5 ± 0.3 mg/dL) for the calves fed the control MR and calves fed the 11, 14, and 17% fat MR, respectively. All calves consumed the MR offered. Daily BW gain (P < 0.05), fecal score (P < 0.1), BCS change (P < 0.1), and hip width change (P < 0.1) were greater from 0 to 42 d for calves fed 0.68 kg of MR vs. calves fed 0.45 kg of MR (Table 5). Within the calves fed 0.68 kg of MR from 0 to 42 d, BW gain (P < 0.05), starter intake (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) increased, and medical treatments (P < 0.1) and fecal scores (P < 0.1) decreased with increasing level of fat. Daily BW gain for individual wk 1 through 4 increased linearly (P < 0.1) with increasing level of fat in the MR; however, there were no differences after wk 4. Feed efficiency was poorest (P < 0.1) for calves fed the control MR fed at 0.45 kg daily. Feed
efficiencies were 0.48, 0.56, 0.58, and 0.61 for the calves fed the control MR and the 11, 14, and 17% fat MR, respectively. Gain of BW (0.81 kg/d), starter intake (0.90 kg/d), hip width change (1.36 cm), BCS change (0.22), and average fecal score (1.15) did not differ (P > 0.1) in the 14 d postweaning. Trial 3. Serum protein concentrations did not differ (P > 0.1; 5.5 ± 0.3 mg/dL) among treatments. All calves consumed the MR offered. Daily gain of BW (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) were less for calves fed the control MR at 0.45 kg daily than other MR (Table 6). Fecal scores were least (P < 0.1) for calves fed the control MR and the 26% CP, 17% fat MR fed at 0.68 kg daily compared to the other MR treatments. Feed efficiencies did not differ (P > 0.1) among treatments. Gain of BW (0.92 kg/d), starter intake (1.02 kg/d), hip width change (1.28
cm), BCS change (1.17), and average fecal score (1.13) did not differ (P > 0.1) in the 14-d post-weaning. Reports of Diaz et al. (2001) and Blome et al. (2003) indicate that increased CP is required when the feeding rate is increased above approximately 0.45 kg in order to increase BW and lean tissue gains. Catherman (2000) reported no change in BW gain when feeding 0.56 vs. 0.45 kg of a 20 or 22% CP, 20% fat MR. However, when considering the increased scouring, lack of BW gain response, or both that occurred in other research trials (Hess et al., 2001; Ballard et al., 2002; Quigley et al., 2006) and field observations (Leadley, 2001), there may be an upper limit of a high CP MR that can be fed in production situations where starter is fed, all calves are weaned, and colostrum management and overall hygiene is less than excellent. The moderate level of 0.68 kg of a 28% CP,
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Feeding Rate and Composition of Milk Replacers
Table 6. Effect of feeding 0.45 kg daily of a control milk replacer vs. 0.68 kg daily of higher CP milk replacer with different fat concentrations (0 to 42 d of age; Trial 3). Milk replacer Item % CP–% fat Rate fed, kg No. of calves Initial calf BW, kg ADG, kg/d Average starter intake, kg/d Average CP intake, kg/d Average fat intake, kg/d Average DE intake, Mcal/d Gain/feed efficiencya Total medical treatments Average fecal scoreb Abnormal fecal score daysb Days with fecal score = 2 Condition score changec Hip width change, cm
A
B
C
D
E
F
SE
20–20 0.45 12 41.4 0.48w 0.50 0.18w 0.11 3.71w 0.51 6.0 1.6y 2.9 15.7y 0.5y 2.5y
26–17 0.68 12 41.3 0.61x 0.48 0.26w 0.13 4.75w 0.54 6.1 1.6y 3.0 20.3z 0.8z 3.2z
26–17 0.77 12 40.9 0.63x 0.44 0.28w 0.15 5.08w 0.54 6.2 1.8z 3.2 21.9z 0.7z 3.2z
28–20 0.68 12 41.7 0.59x 0.46 0.27w 0.15 4.83w 0.53 6.5 1.8z 3.3 23.3z 0.7z 2.9z
28–17 0.68 12 41.4 0.58x 0.46 0.27w 0.13 4.72w 0.52 6.5 1.9z 3.2 23.3z 0.7z 3.0z
26–20 0.68 12 41.3 0.59x 0.47 0.26w 0.15 4.83w 0.53 6.37 1.9z 3.2 24.1z 0.7z 2.9z
— — — 3.9 0.04 0.05 0.02 0.02 0.51 0.03 0.89 0.05 0.41 2.1 0.08 0.18
a
Gain divided by starter plus milk replacer intake. Milk replacer intake from 0 to 6 wk when it was fed averaged 0.44 kg for the group fed 0.45 kg MR, 0.65 kg for the group fed 0.68 kg MR, and .74 kg for the group fed 0.77 kg MR. b Fecal scores: 1 = normal, thick in consistency; 2 = normal, but less thick; 3 = abnormally thin but not watery; 4 = watery; 5 = watery with abnormal coloring. Abnormal fecal scores were days with scores > 2. c 1 to 5 system with 1 = emaciated and 5 = obese. wx Means with different superscripts differ (P < 0.05). yz Means with different superscripts differ (P < 0.1).
20% fat MR was reported to increase BW gain by 55%, as well as efficiency, but slightly decrease starter intake (Hill et al., 2006). Bartlett et al. (2006) reported that lactose is utilized better than fat in calves that were not introduced to the experimental treatments until after a high fat, pre-trial MR was fed for 3 wk with no starter being fed. Tikofsky et al. (2001) suggested that feeding approximately 1 kg of a 23.5% CP, 14.7% fat MR (with no starter fed) was optimum in calves that were not weaned based on observations that the greater fat MR resulted in more fat deposition but similar protein deposition. Thus, optimum CP concentration might be around 23%, and fat at more than 15% would likely result in fat gain but not CP gain. Hill et al. (2006) observed depressed starter intake when a 28% CP, 20% fat MR was fed at
0.68 kg daily and suggested that a fat level of less than 20% might be required to avoid depressing starter intake. Considering these observations, MR fed at 0.68 kg daily containing from 22 to 28% CP (Trial 1) and 11 to 17% fat (Trial 2) were evaluated. Our MR treatments were not formulated or fed to be isocaloric like in trials of Tikofsky et al. (2001), Bartlett et al. (2006), and Blome et al. (2003). Additionally, some of our fat concentrations were less than the least concentrations fed in MR of Tikofsky et al. (2001; 14.7% fat) and Bartlett et al. (2006; 19% fat). In Trials 1 and 2, it was evident that both the concentration of CP and fat in the MR fed at 0.68 kg daily affected calf performance. Increasing the CP in the MR fed at 0.68 kg daily increased BW gains up to 26% CP. In Trial 3, the calves fed 0.68 kg of the MR containing 26 and 28% CP had
similar performance. In Trial 2, calf gain increased linearly from 11 to 17% fat in the MR fed at 0.68 kg/d. In retrospect, a concentration of fat greater than 17% should have been included; however, calves fed 0.68 kg of the 20% fat MR did not perform better than calves fed the 17% fat MR in Trial 3. Fat may be important in the early weeks of a calf’s life beyond influencing daily gain. Heat production has been shown to decrease with age and increase with stress and declining environmental temperatures in calves less than 2 wk of age (Schrama et al., 1995a,b, 1996). The slight conflict between our observations and the results of Bartlett et al. (2006) is likely explained by the age of their calves vs. calves in Trial 2. They used calves that were introduced to the experimental treatments at approximately 3 wk of age, after whole milk was fed
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during a pre-trial period. A high-fat MR may be utilized better during the first few weeks of a calf’s life (Trial 2), and a high-lactose, low-fat MR may be utilized better thereafter (Bartlett et al., 2006). However, it is important to consider that a 2-phase MR program (a high-fat MR, followed by a lower fat MR) would complicate feeding management and may be impractical on many operations. Results from Trial 3 confirmed that 26% CP and 17% fat are near optimum for a MR fed at 0.68 kg daily. The calves fed the 3 MR with combinations of 1) 28% CP, 20% fat, 2) 28% CP, 17% fat, and 3) 26% CP, 20% fat did not improve performance (statistically or numerically) compared to calves fed the 26% CP, 17% fat MR. Consistent with our data, Ballard et al. (2002) reported a greater intake of starter, greater BW gains, and greater increase in BCS, and a trend for the calves to be taller, longer, and of larger girth when they fed a 27% CP MR with 15 vs. 20% fat. The calves fed the 26% CP, 17% fat MR at 0.68 and 0.77 kg daily performed similarly (P > 0.1). Quigley et al. (2006) reported depressed starter intake and increased scouring and mortality when feeding 0.9 kg of a 28% CP, 15% fat MR. Our observations suggest that 0.68 to 0.77 kg of MR fed daily is near the maximum amount to feed without increasing the risk of health problems. Post-weaning performance did not differ for any treatment in Trial 1, 2, or 3. This is important to note because in past trials calves fed high levels of milk or MR typically have lesser BW gains (Bar-Peled et al., 1997; Jasper and Weary, 2002; Hill et al., 2006), lesser starter intakes, and poorer feed efficiencies at weaning time and post-weaning (Strzetelski et al., 2001; Jasper and Weary, 2002; Hill et al., 2006). It is difficult to fully discern differences between our current trial and previously published trials. Diaz et al. (2001) and our current trials used calves that were less than 1 wk old,
Hill et al.
whereas Blome et al. (2003) and Bartlett et al. (2006) used calves that were over 2 wk old. Based on our review of the literature, we believe that we were the only researchers to feed starter and to castrate, dehorn, and wean the calves when multiple amounts of nutrients were fed over a control. In Trial 1, the calves fed 0.68 kg of 26% CP, 13% fat MR averaged 56 kg BW and consumed 1.06 kg DM, 0.26 kg CP, 4.55 Mcal DE, and gained 0.63 kg BW daily. In Trial 2, the calves fed 0.68 kg of 24% CP, 17% fat MR averaged 55 kg BW and consumed 1.02 kg DM, 0.24 kg CP, 4.53 Mcal DE, and gained 0.63 kg BW daily. In Trial 3, the calves fed 0.68 kg of 26% CP, 17% fat MR averaged 54 kg BW and consumed 1.08 kg DM, 0.26 kg CP, 4.75 Mcal DE, and gained 0.61 kg BW daily. Equations in the NRC (2001) suggest approximately 1.0 kg DM, 0.22 kg CP, and 4.4 Mcal DE daily is required to support these ADG in 55-kg BW calves when both MR and starter is fed. Based on the performance of calves in Trials 1 and 3, their requirement for CP was approximately 18% more (0.26 vs. 0.22 kg CP/d) than suggested by NRC 2001. However, the requirement for DE of the calves in Trials 1, 2, and 3 were approximately 5% more than suggested by NRC 2001. The groups of calves fed the least MR (both on DM basis: 31.2% CP, 20.0% fat, 96% DM) in Diaz et al. (2001) were most similar to our calves. These calves averaged 55 and 56 kg BW, consumed 0.8 and 1.2 kg of MR DM (no starter), 0.24 and 0.35 kg CP, 3.86 and 6.04 Mcal DE, and gained 0.52 and 0.94 kg BW daily. Their calves fed 0.8 kg of MR may have been limited by energy intake. The fastest growing calves in trial of Blome et al. (2003) averaged 58 kg BW, consumed 0.8 kg (DM basis: 25.8% CP, 18.6% fat, 97% DM) of MR DM (no starter), 0.21 kg CP, 4.01 Mcal DE, and gained 0.62 kg BW daily. The fastest growing calves in the trial of Bartlett et al. (2006) averaged 57 and 58 kg, consumed 0.96 kg (DM basis: 22.3% CP, 21.4% fat, 97%
DM) and 0.99 kg (DM basis: 24.8% CP, 18.9% fat, 97% DM) of MR DM (no starter), 0.22 and 0.25 kg of CP, 4.74 and 4.87 Mcal DE and gained 0.69 and 0.70 kg BW daily, respectively. Our calves may have required more energy and CP than calves in the other trials because we fed starter, castrated, dehorned, and weaned the calves. Additionally, our calves were multiple-source calves that were transported approximately 10 h to our research nursery. Efficiency of nutrient use decreases and requirements estimated from the NRC 2001 when starter and MR are fed vs. MR alone increase. A similar situation may occur when normal management practices are carried out on milk-fed calves. Alternatively, an allowance could be made to increase maintenance requirements of the calf to allow for increased energy and protein needs from stress associated with normal management practices. Even with the variation in initial calf age (< 1 to > 3 wk), management (dehorning, castrastion), and diet (starter fed or not fed) among published trials of Diaz et al. (2001), Blome et al. (2003), Bartlett et al. (2006), and our trials, estimates of CP and energy requirements to support 0.6 to 0.7 kg/d of BW gain were within approximately 20% of each other and equations of the NRC (2001).
Implications Feeding 0.68 kg of a 26% CP, 17% fat MR to neonatal calves less than 8 wk of age fed starter appeared near optimum. Additionally, this MR composition and rate did not have a negative effect on starter intake, efficiency, and post-weaning performance compared to the control 20% CP, 20% fat MR fed at 0.45 kg daily. The amounts of MR fed did not have to be changed with age of the calf, fecal scores and health issues were not perturbed, and overall management needs were not increased relative to the control MR. Research in calves less than 8 wk of age is needed on amino acids rather than CP and spe-
Feeding Rate and Composition of Milk Replacers
cific fatty acids rather than fat or energy requirements because these data are not available. More research is needed to determine the effects MR rates exceeding 0.68 kg daily on early post-weaning growth to minimize the growth slumps frequently reported.
Literature Cited AOAC. 1996. Official Methods of Analysis. Vol. I 16th ed. Association of Official Analytical Chemists, Arlington, VA. Ballard, C. S., H. M. Wolford, C. J. Sniffen, .M. P. Carter, P. Mandebvu, T. Sato, Y. Yabuuchi, and M. Van Amburgh. 2002. The effect of feeding three milk replacer regimes on calf intake, BW gain, and animal performance. J. Dairy Sci. 85(Suppl. 1):67.(Abstr.) Bar-Peled, U., B. Robinzon, E. Maltz, H. Tagari, Y. Folman, I. Bruckental, H. Voet, H. Gacitua, and A. R. Lehrer. 1997. Increased weight gain and effects on production parameters of Holstein heifer calves that were allowed to suckle from birth to six weeks of age. J. Dairy Sci. 80:2523. Bartlett, K. S., F. K. McKeith, M. J. Vandehaar, G. E. Dahl, and J. K. Drackley. 2006. Growth and body composition of dairy calves fed milk replacers containing different amounts of protein at two feeding rates. J. Anim. Sci. 84:1454.
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Blome, R. M., J. K. Drackley, F. K. McKeith, M. F. Hutjens, and G. C. McCoy. 2003. Growth, nutrient utilization, and body composition of dairy calves fed milk replacers containing different amounts of protein. J. Anim. Sci. 81:1641.
In Proceedings Cornell Nutrition Conference for Feed Manufacturers. p 56. Ithaca, NY.
Brown, E. G., M. J. VandeHaar, K. M. Daniels, J. S. Liesman, L. T. Chaplin, D. H. Keisler, and M. S. Weber Nielson. 2005. Effect of increasing energy and protein intake on growth and carcass composition of heifer calves. J. Dairy Sci. 88:585.
Quigley III, J. D., T. A. Wolfe, and T. H. Elsasser. 2006. Effect of additional milk replacer feeding on calf health, growth, and selected blood metabolites in calves. J. Dairy Sci. 89:207.
NRC. 2001. Nutrient Requirements of Dairy Cattle, 7th rev. ed. Natl. Acad. Press, Washington, D.C.
Catherman, D. R. 2000. Effect of increased milk replacer consumption on performance and economics in Holstein heifer calves. J. Dairy Sci. 83(Suppl. 1):235(Abstr.)
Schrama, J. W., M. J. W. Heetkamp, M. W. A. Verstegen, W. G. P. Schouten, F. van der Veen, and F. A. Helmond. 1996. Responses to young calves, on two levels of feeding, to transportation. Anim. Sci. 63:79.
Diaz, M. C., M. E. Van Amburg, J. M. Smith, J. M. Kelsey, and E. L. Hutten. 2001. Composition of growth of Holstein calves fed milk replacer from birth to 105-kilogram BW. J. Dairy Sci. 84:830.
Schrama, J. W., J. P. A. Roefs, J. Gorssen, M. J. W. Heetkamp, and M. W. A. Verstegen. 1995a. Alteration of heat production in young calves in relation to posture. J. Anim. Sci. 73:2254.
FASS. 1999. Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching. 1st rev. ed. Fed. Anim. Sci. Soc., Savoy, IL.
Schrama, J. W., W. van der Hel, and M. W. A. Verstegen. 1995b. Development of metabolic partitioning of energy in young calves. J. Dairy Sci. 78:1154.
Hess, S. M., R. D. Shanks, and M. F. Hutjens. 2001. Accelerated calf growing program. In 2001 Dairy Report. p 20. Univ. Illinois, Champaign.
Strzetelski, J., B. Niwinska, J. Kowalezyk, and A. Jurkiewiez. 2001. Effect of milk replacer feeding frequency and level of concentrate intake and rearing performance of calves. J. Anim. Feed Sci. 10:413.
Hill, T. M., J. M. Aldrich, R. L. Schlotterbeck, and H. G. Bateman, II. 2006. Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period. Prof. Anim. Sci. 22:252. Jasper, J., and D. M. Weary. 2002. Effects of ad libitum milk intake on dairy calves. J. Dairy Sci. 85:3054. Leadley, S. M. 2001. Accelerated calf growth: New York commercial dairy farm experience.
Tikofsky, J. N., M. E. Van Amburgh, and D. A. Ross. 2001. Effect of varying charbohydrate and fat content of milk replacer on body composition of Holstein bull calves. J. Anim. Sci. 79:2260. Wildman, E. E., G. M. Jones, P. E. Wagner, R. L. Boman, H. F. Trout, Jr., and T. N. Lesch. 1982. A dairy cow body condition scoring system and its relationship to selected production characteristics. J. Dairy Sci. 65:495.
Effects of Feeding Rate and Concentrations of Protein and Fat of Milk Replacers Fed to Neonatal Calves T. M. HILL,1 J. M. ALDRICH, PAS, R. L. SCHLOTTERBECK, and H. G. BATEMAN,II Akey, Nutrition and Research Center, Lewisburg, OH 45338
Abstract Three trials were conducted to examine the effects of feeding rate and concentration of CP and fat in the milk replacer (MR) on calf performance. In all trials, Holstein bull calves (41 to 42 kg average initial BW; less than 7-d old) were randomly assigned to MR treatments and fed fixed amounts of MR with free-choice starter and water for 6 wk. Calves were fed starter and water after 6 wk. Calves were weighed initially and weekly. Starter intake was measured and fecal scores and medical treatments recorded daily. In all trials, a conventional 20% CP, 20% fat MR fed at 0.45 kg daily served as the control treatment. Trial 1 included CP concentrations ranging from 22 to 28% in MR fed at 0.68 kg daily. Trial 2 included fat concentrations from 11 to 17% in MR fed at 0.68 kg daily. Calves were weaned at 42 d and measurements were recorded through 56 d. In each trial, calves fed the control MR gained the slowest. When 0.68 kg daily of a 13% fat MR was fed with CP concentrations from 22 to 28%, BW gains increased linearly (optimum of 26%) and starter intake was no different
1
To whom correspondence should be addressed: email: [email protected]
from the control. When 0.68 kg daily of a 24% CP MR was fed with fat concentrations between 11 and 17%, BW gains increased linearly and starter intake was not different from the control. Trial 3 was conducted with MR of 26 and 28% CP and 17 and 20% fat fed at 0.68 or 0.77 kg daily. Calf BW gains did not differ among MR fed at 0.68 and 0.77 kg daily. Performance data from these trials indicate that a MR fed at 0.68 kg daily should contain approximately 26% CP and 17% fat, with no results suggesting that starter intake or efficiency would be reduced or scouring would be increased compared to a conventional 20% CP, 20% fat MR fed at 0.45 kg. Key words: calves, protein, fat, growth
Introduction There is considerable discussion in our current dairy industry regarding feeding high protein milk replacers (MR) to neonatal calves. Diaz et al. (2001) fed calves a 30% milk CP, 20% fat MR diet (with no dry starter feed) at varying rates up to a maximum consumption of 2.5 kg of dry milk powder daily and reported increasing daily BW gains and feed efficiencies with increasing intake of powder, suggesting that neonatal
calves should be fed for faster rates of BW gain and require more CP than typical of industry practices. This is consistent with protein requirements outlined in Chapter 10 of the dairy NRC (2001) and subsequent research of Blome et al. (2003). Brown et al. (2005) and Quigley et al. (2006) reported improved BW gains, reduced starter intakes, and better feed efficiencies when calves were fed approximately 0.9 kg of 28% CP MR, but Hess et al. (2001) reported similar BW gains and starter intakes with lesser feed efficiencies when 0.69 kg of a 30% CP MR was fed compared to feeding 0.38 to 0.5 kg of a 20% CP, 20% fat MR. All reported increased sickness in calves receiving a greater rate of MR. We observed no change in BW gain and efficiency with decreased starter intake and increased sickness in 2 trials in which we fed 1.13 and 1.36 kg of a 28% CP, 20% fat MR (Hill et al., 2006). However, we observed 55% faster BW gains and more desirable efficiency with moderate decreases in starter intake (11%) and increases in medical treatments (27%) when we fed 0.68 kg of a 28% CP, 20% fat MR in a third trial compared to feeding 0.45 kg of a 20% CP, 20% fat MR. The moderate feeding rate of 0.68 kg of a 28% CP, 20% fat MR appeared more promising
Feeding Rate and Composition of Milk Replacers
than greater feeding rates of more than 1 kg daily, yet starter intake was slightly reduced and medical treatments slightly increased (Hill et al., 2006). The overall objective of these trials was to identify a MR program fed with starter that would yield faster growth (with minimum health and management challenges) than are currently achieved in the industry with conventional MR fed at approximately 0.45 kg daily. The objectives of the first 2 research trials were to feed a moderate rate (0.68 kg daily) of a MR containing various CP (22 to 28%) and fat (11 to 17%) concentrations with starter feed offered to determine their effects on BW gain, starter intake, and calf health. The objective of the third trial was to feed a more narrow range of protein and fat concentrations in MR fed at 0.68 and 0.77 kg daily to determine their effects on BW gain, starter intake and calf health.
Materials and Methods Trial 1. Fifty calves were fed 1 of 5 treatments. Treatment 1A was a control 20% CP, 20% fat MR fed at 0.45 kg daily. The other 4 MR treatments contained 13% fat, were fed at 0.68 kg daily, and were 1B) 22% CP, 1C) 24% CP, 1D) 26% CP, and 1E) 28% CP. Trial 2. Forty-eight calves were fed 1 of 4 treatments. Treatment 2A was a control 20% CP, 20% fat MR fed at 0.45 kg daily. The other 3 MR treatments contained 24% CP, were fed at 0.68 kg daily, and were 2B) 11% fat, 2C) 14% fat, and 2D) 17% fat. Trial 3. Seventy-two calves were fed 1 of 6 MR treatments. Treatment 3A was a control 20% CP, 20% fat MR fed at 0.45 kg daily. The other 5 treatments were 3B) 0.68 kg daily of a 26% CP, 17% fat MR, 3C) 0.77 kg daily of a 26% CP, 17% fat MR, 3D) 0.68 kg daily of a 28% CP, 20% fat MR, 3E) 0.68 kg daily of a 28% CP, 17% fat MR, and 3F) 0.68 kg daily of a 26% CP, 20% fat MR.
Feeds. All calves received a common pelleted starter formulated (asfed basis) to be 18% CP, 0.7% Ca, and 0.5% P and contain 65% corn, 23% soybean meal, 5% wheat midds, 2.5% of a protein blend (73% CP, asfed basis; Papillon Ag. Products, Inc., Easton, MD), macrominerals, trace minerals, vitamins, and decoquinate (0.025 mg/kg). The formulas for the MR are shown in Table 1. The feeds were assayed (AOAC, 1996) for CP, fat, ash, Ca, and P (Tables 2 and 3). Animals, Preventative Health Management, and Measurements. Holstein bull calves were received from multiple dairies at less than 1 wk of age after a 10-hour transit and immediately fed 113 g of electrolyte (80% dextrose, 6% Na, 1% K) reconstituted to 2 L with warm water. Approximately 12 h later the calves were weighed and randomly assigned to treatment by weight. After blood was sampled intravenously for serum protein determination via a refractometer, calves were offered their respective MR treatment. Calves were initially fed 0.23 kg of MR reconstituted to 1.9 L with warm water twice daily at approximately 12-h intervals. Calves that were to be fed 0.68 or 0.77 kg of MR daily were initially fed 0.45 kg daily and then increased to 0.68 or 0.77 kg of MR on d 3. All MR were reconstituted at the rate of 0.12 kg MR powder/L of liquid volume. Calves were weaned by feeding 50% of the daily MR in the a.m. only for 2 d. In all trials, calves were weaned at 6 wk of age and measurements were recorded to 8 wk of age. Calves were weighed initially and weekly thereafter midway between a.m. and p.m. feedings. Initial BW were 42 ± 2 kg for Trials 1 and 2 and 41 ± 2 kg for Trial 3. Dry starter feed was offered initially on d 3 and refused and fresh feed were weighed daily. Fecal scores were assigned daily based on a 1 to 5 system (1 being normal, thick in consistency; 2 being normal, but less thick; 3 being abnormally thin but not watery; 4 being watery; 5 being watery with abnormal coloring). Body condition
375
was scored and hip widths measured at time of initial weighing and at 2, 4, 6, and 8 wk thereafter. Body condition score (BCS) was based on a 1 to 5 system using 0.25 unit increments with 1 being emaciated and 5 being obese (Wildman et al., 1982). Scores were based on changes around the vertical and transverse processes of the spine as palpated by one experienced technician and ranged from 1.75 to 3.5. Vaccines and health protocols were based on the recommendations of a veterinarian. Calves received an intranasal tissue-sensitive respiratory disease vaccine (TSV-2, Pfizer, Exton, PA) and subcutaneous injections of vitamins A, D, and E (Vital E-A + D, Schering-Plough Animal Health, Union, NJ) and Se (MU-SE, ScheringPlough Animal Health, Union, NJ) upon arrival. Calves received an intramuscular respiratory disease vaccine (Bovashield Gold 5, Pfizer, Exton, PA) at d 7 and again at d 28. At d 14 they received an intramuscular vaccine for types C and D clostridium (Ultra Choice 7, Pfizer, Exton, PA). A pasturella vaccine (Presponse HM, Fort Dodge, Fort Dodge, IA) was administered intramuscularly on d 28 and 42. Calves were castrated and dehorned on d 36. Animals that required medication for digestive (subcutaneous ceftiofur sodium, Naxcel, Pharmacia & Upjohn, Kalamazoo, MI) or navel (subcutaneous penicillin G procaine, Agri-Cillin, AgriLabs, St. Joseph, MO) infections were treated per veterinary recommendation and treatments were recorded daily. Digestive infections were diagnosed based on rectal temperatures (>39.5°C), lack of vitality, and fecal scores > 2. Over 95% of the medical treatments were because of digestive upsets (scouring) with the remainder for navel infections that were not included in the reported treatments. Calves were housed a curtain-sided, naturally ventilated barn with no added heat in 1.2 m by 2.4 m pens bedded with straw. Calves had access to clean, fresh water at all times. All animals were cared for by acceptable
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Hill et al.
Table 1. Ingredient composition of milk replacers used in Trials 1, 2, and 3 (as-fed basis). Milk replacera Item Trial Target % CP Target % fat DE, Mcal/kg Rate fed, kg Ingredient, % Whey Dry fat, 60% WPC,b 34% WPC, 45% Premixc Decoquinated Dicalcium P
A
B
C
D
E
B
C
D
B
C
D
E
F
All 20 20 4.96 0.45
1 22 13 4.64 0.68
1 24 13 4.67 0.68
1 26 13 4.70 0.68
1 28 13 4.74 0.68
2 24 11 4.57 0.68
2 24 14 4.72 0.68
2 24 17 4.88 0.68
3 26 17 4.91 0.68
3 26 17 4.91 0.77
3 28 20 5.10 0.68
3 28 17 4.95 0.68
3 26 20 5.07 0.68
34.5 28.6 18.9 15.5 1.3 1.0 0.2
41.9 16.5 24.4 15.5 1.0 0.7 —
33.9 16.2 32.7 15.5 1.0 0.7 —
25.9 15.9 41.0 15.5 1.0 0.7 —
17.8 15.7 49.3 15.5 1.0 0.7 —
37.9 12.9 32.0 15.5 1.0 0.7 —
31.9 17.9 33.0 15.5 1.0 0.7 —
25.8 22.9 34.1 15.5 1.0 0.7 —
17.8 22.6 42.4 15.5 1.0 0.7 —
17.9 22.6 42.4 15.5 1.0 0.6 —
3.9 27.4 51.5 15.5 1.0 0.7 —
9.8 22.3 50.7 15.5 1.0 0.7 v
11.8 27.6 43.4 15.5 1.0 0.7 —
a
Milk replacers B and C in Trial 3 were made as one batch. Whey protein concentrate. c Labeled concentrations of vitamin, mineral premix were: 0.03 g selenium/kg, 7,700 KIU vitamin A/kg. d Concentration: 5 g/kg; Alpharma, Inc., Fort Lee, NJ. b
practices as described in the Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching (FASS, 1999). Statistical Analysis. Data were analyzed by trial as a completely randomized block design using the GLM procedure of SAS (SAS Inst., Inc., Cary, NC). Effects of block (initial BW) and diet were considered random and fixed effects, respectively. Starter intake, fecal score, and medical treatment data were first pooled by week then analyzed. There was no sub-sampling and data reported are least square means for the experimental unit (calf). In Trials 1 and 2, if differences among the treatment diets were significant (P < 0.1), an orthogonal polynomial contrast for level of MR fed (0.45 vs. 0.68 kg daily) and orthogonal polynomial contrasts for linear and quadratic effects among the treatment diets fed at the 0.68 kg daily level were conducted to further characterize differences. In Trial 3, if differences among the treatment diets were significant (P < 0.1), treatment means were separated using the Student-Newman-Keuls test in SAS (SAS Inst., Inc.). In cases where P < 0.1, dif-
trol), 22, 24, 26, and 28% CP MR, respectively. All calves consumed the MR offered. Daily BW gain (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) were improved from 0 to 42 d when 0.68 kg of MR was fed compared to when 0.45 kg of MR was fed (Table 4). For the individual weeks of 2, 3, 4, 5, and 6, BW gain
ferences among fixed effects were considered significant.
Results and Discussion Trial 1. Serum protein concentrations did not differ (P > 0.1; 5.5 ± 0.3 mg/dL) for calves fed the 20 (con-
Table 2. Analyzed nutrient content of milk replacers and starter used in Trials 1 and 2 (as-fed basis). Milk replacera A Trial Target % CP Target % fat Rate fed, kg/d Analysis Moisture, % CP, % Fat, % Ash, % Ca, % P, % a
B
C
D
E
B
C
D
Starter
1, 2 1 1 1 1 2 2 2 20 22 24 26 28 24 24 24 20 13 13 13 13 11 14 17 0.45 0.68 0.68 0.68 0.68 0.68 0.68 0.68
1, 2 18 — —
3.3 3.3 3.4 3.4 3.2 3.5 3.3 3.3 20.1 22.1 24.1 26.0 28.1 24.0 24.1 24.2 20.2 13.2 13.0 13.1 13.2 11.3 14.2 17.1 6.5 6.3 6.2 6.0 5.9 6.3 6.2 6.3 0.76 0.77 0.80 0.82 0.86 0.82 0.81 0.82 0.61 0.62 0.62 0.64 0.65 0.62 0.63 0.61
11.8 18.0 3.7 4.9 0.88 0.53
Milk replacer A and the starter used in Trials 1 and 2 were made as one batch prior to Trial 1. Starter calculated to 2.95 Mcal digestible energy/kg.
377
Feeding Rate and Composition of Milk Replacers
Table 3. Analyzed nutrient content of milk replacers and starter used in Trial 3 (as-fed basis). Milk replacera Item Target % CP Target % fat Rate fed, kg/d Analysis Moisture, % CP, % Fat, % Ash, % Ca, % P, %
A
B
C
D
E
F
Starter
20 20 0.45
26 17 0.68
26 17 0.77
28 20 0.68
28 17 0.68
26 20 0.68
18 — —
3.3 20.1 20.2 6.6 0.77 0.60
3.2 26.0 17.2 5.8 0.84 0.65
3.3 26.3 17.0 5.7 0.85 0.65
3.3 28.1 19.9 5.5 0.84 0.64
3.2 28.1 17.0 5.6 0.85 0.66
3.3 26.0 20.0 5.6 0.85 0.65
12.0 18.0 3.8 5.1 0.90 0.52
a
Milk replacers B and C were made as one batch but analyzed separately. Starter calculated to 2.95 Mcal of digestible energy/kg.
was improved (P < 0.1) when 0.68 kg of MR was fed compared to when
0.45 kg of MR was fed. Within the calves fed 0.68 kg of MR, BW gain
was increased quadratically (P < 0.05) from 0 to 42 d with increasing level of CP. Within the calves fed 0.68 kg of MR, daily starter intake (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) increased in a linear manner from 0 to 42 d with increasing level of CP. Within the calves fed 0.68 kg of MR for the individual weeks of 2, 3, 4, 5, and 6, BW gains and starter intake increased in a linear manner (P < 0.1) with increasing level of CP; however, BW gain was maximized at 26% CP. Feed efficiencies (gain per feed) did not differ (P > 0.1) from 0 to 42 d and were 0.49, 0.50, 0.51, 0.58, and 0.51 for calves fed the 20 (control), 22, 24, 26, and 28% CP MR, respectively. Gain of BW (0.89 kg/d), starter intake (1.03 kg/d), hip width change (1.12 cm), BCS change (1.13), and average fecal score (1.13) did not differ (P > 0.1) in the 14 d post-weaning.
Table 4. Effect of feeding a 20% CP, 20% fat milk replacer at 0.45 kg daily compared to feeding a 13% fat milk replacer at 0.68 kg daily that contained 22, 24, 26, or 28% CP (0 to 42 d of age; Trial 1). Milk replacer Item CP, % Rate fed, kg/d No. of calves Initial calf BW, kg ADG, kg/d Average starter intake, kg/d Average CP intake, kg/d Average fat intake, kg/d Average DE intake, Mcal/d Gain/feed efficiencyb Total medical treatments Average fecal scorec Abnormal fecal score daysc Days with fecal score = 2 Condition score changed Hip width change, cm
A
B
C
D
E
SE
Significancea
20 0.45 10 42.1 0.46 0.50 0.18 0.11 3.71 0.49 6.0 1.7 2.9 15.8 1.0 2.7
22 0.68 10 42.8 0.50 0.38 0.22 0.10 4.28 0.50 5.2 1.8 2.6 21.2 1.1 2.8
24 0.68 10 41.7 0.54 0.43 0.24 0.11 4.44 0.51 6.6 1.8 3.3 21.0 1.2 2.9
26 0.68 10 42.3 0.63 0.46 0.26 0.11 4.55 0.58 5.0 1.7 2.4 19.2 1.3 3.1
28 0.68 10 42.5 0.63 0.62 0.30 0.11 5.05 0.51 6.8 1.8 3.3 21.1 1.3 3.2
— — — 4.1 0.04 0.03 0.01 0.01 0.29 0.03 0.92 0.06 0.44 2.2 0.11 0.22
— — — — CO, Q L CO, L — CO, l — — — — co co, l co, l
CO = control vs. other MR (P < 0.05); co = control vs. other MR (P < 0.1); Q = quadratic effect of level of protein in 13% fat MR (P < 0.05); L = linear effect of level of protein in 13% fat MR (P < 0.05); l = linear effect of level of protein in 13% fat MR (P < 0.1). b Gain divided by starter plus milk replacer intake. Milk replacer intake from 0 to 6 wk when it was fed averaged 0.44 kg for the group fed 0.45 kg MR and 0.65 kg for the group fed 0.68 kg MR. c Fecal scores: 1 = normal, thick in consistency; 2 = normal, but less thick; 3 = abnormally thin but not watery; 4 = watery; 5 = watery with abnormal coloring. Abnormal fecal scores were days with scores > 2. d 1 to 5 system with 1 = emaciated and 5 = obese. a
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Hill et al.
Table 5. Effect of feeding a 20% CP, 20% fat milk replacer at 0.45 kg daily or feeding a 24% CP milk replacer at 0.68 kg daily that contained 11, 14, or 17% fat (0 to 42 d of age; Trial 2). Milk replacer Item Fat, % Rate fed, kg/d No. of calves Initial calf BW, kg ADG, kg/d Average starter intake, kg/d Average CP intake, kg/d Average fat intake, kg/d Average DE intake, Mcal/d Gain/feed efficiencyb Total medical treatments Average fecal scorec Abnormal fecal score daysc Days with fecal score = 2 Condition score changed Hip width change, cm
A
B
C
D
SE
Significancea
20 0.45 12 41.8 0.40 0.39 0.16 0.11 3.38 0.48 5.9 1.6 2.9 16.1 0.5 2.0
11 0.68 12 42.0 0.54 0.33 0.22 0.09 4.08 0.56 6.5 1.9 3.2 22.2 0.6 2.3
14 0.68 12 42.4 0.59 0.39 0.23 0.11 4.36 0.58 6.4 1.7 3.1 21.9 0.7 2.6
17 0.68 12 42.1 0.63 0.41 0.24 0.13 4.53 0.61 6.2 1.6 3.0 21.9 0.9 2.8
— — — 4.0 0.04 0.03 0.01 0.01 0.31 0.03 0.42 0.05 0.23 22.1 0.09 0.12
— — — — N, L L CO L CO, l n l n, l l n n, l n, l
N = control vs. other MR (P < 0.05); n = control vs. other MR (P < 0.1); L = linear effect of level of protein in 13% fat MR (P < 0.05); l = linear effect of level of protein in 13% fat MR (P < 0.1). b Gain divided by starter plus milk replacer intake. Milk replacer intake from 0 to 6 wk when it was fed averaged 0.44 kg for the group fed 0.45 kg MR and 0.65 kg for the group fed 0.68 kg MR. c Fecal scores: 1 = normal, thick in consistency; 2 = normal, but less thick; 3 = abnormally thin but not watery; 4 = watery; 5 = watery with abnormal coloring. Abnormal fecal scores were days with scores > 2. d 1 to 5 system with 1 = emaciated and 5 = obese. a
Trial 2. Serum protein concentrations did not differ (P > 0.1, 5.5 ± 0.3 mg/dL) for the calves fed the control MR and calves fed the 11, 14, and 17% fat MR, respectively. All calves consumed the MR offered. Daily BW gain (P < 0.05), fecal score (P < 0.1), BCS change (P < 0.1), and hip width change (P < 0.1) were greater from 0 to 42 d for calves fed 0.68 kg of MR vs. calves fed 0.45 kg of MR (Table 5). Within the calves fed 0.68 kg of MR from 0 to 42 d, BW gain (P < 0.05), starter intake (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) increased, and medical treatments (P < 0.1) and fecal scores (P < 0.1) decreased with increasing level of fat. Daily BW gain for individual wk 1 through 4 increased linearly (P < 0.1) with increasing level of fat in the MR; however, there were no differences after wk 4. Feed efficiency was poorest (P < 0.1) for calves fed the control MR fed at 0.45 kg daily. Feed
efficiencies were 0.48, 0.56, 0.58, and 0.61 for the calves fed the control MR and the 11, 14, and 17% fat MR, respectively. Gain of BW (0.81 kg/d), starter intake (0.90 kg/d), hip width change (1.36 cm), BCS change (0.22), and average fecal score (1.15) did not differ (P > 0.1) in the 14 d postweaning. Trial 3. Serum protein concentrations did not differ (P > 0.1; 5.5 ± 0.3 mg/dL) among treatments. All calves consumed the MR offered. Daily gain of BW (P < 0.05), BCS change (P < 0.1), and hip width change (P < 0.1) were less for calves fed the control MR at 0.45 kg daily than other MR (Table 6). Fecal scores were least (P < 0.1) for calves fed the control MR and the 26% CP, 17% fat MR fed at 0.68 kg daily compared to the other MR treatments. Feed efficiencies did not differ (P > 0.1) among treatments. Gain of BW (0.92 kg/d), starter intake (1.02 kg/d), hip width change (1.28
cm), BCS change (1.17), and average fecal score (1.13) did not differ (P > 0.1) in the 14-d post-weaning. Reports of Diaz et al. (2001) and Blome et al. (2003) indicate that increased CP is required when the feeding rate is increased above approximately 0.45 kg in order to increase BW and lean tissue gains. Catherman (2000) reported no change in BW gain when feeding 0.56 vs. 0.45 kg of a 20 or 22% CP, 20% fat MR. However, when considering the increased scouring, lack of BW gain response, or both that occurred in other research trials (Hess et al., 2001; Ballard et al., 2002; Quigley et al., 2006) and field observations (Leadley, 2001), there may be an upper limit of a high CP MR that can be fed in production situations where starter is fed, all calves are weaned, and colostrum management and overall hygiene is less than excellent. The moderate level of 0.68 kg of a 28% CP,
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Feeding Rate and Composition of Milk Replacers
Table 6. Effect of feeding 0.45 kg daily of a control milk replacer vs. 0.68 kg daily of higher CP milk replacer with different fat concentrations (0 to 42 d of age; Trial 3). Milk replacer Item % CP–% fat Rate fed, kg No. of calves Initial calf BW, kg ADG, kg/d Average starter intake, kg/d Average CP intake, kg/d Average fat intake, kg/d Average DE intake, Mcal/d Gain/feed efficiencya Total medical treatments Average fecal scoreb Abnormal fecal score daysb Days with fecal score = 2 Condition score changec Hip width change, cm
A
B
C
D
E
F
SE
20–20 0.45 12 41.4 0.48w 0.50 0.18w 0.11 3.71w 0.51 6.0 1.6y 2.9 15.7y 0.5y 2.5y
26–17 0.68 12 41.3 0.61x 0.48 0.26w 0.13 4.75w 0.54 6.1 1.6y 3.0 20.3z 0.8z 3.2z
26–17 0.77 12 40.9 0.63x 0.44 0.28w 0.15 5.08w 0.54 6.2 1.8z 3.2 21.9z 0.7z 3.2z
28–20 0.68 12 41.7 0.59x 0.46 0.27w 0.15 4.83w 0.53 6.5 1.8z 3.3 23.3z 0.7z 2.9z
28–17 0.68 12 41.4 0.58x 0.46 0.27w 0.13 4.72w 0.52 6.5 1.9z 3.2 23.3z 0.7z 3.0z
26–20 0.68 12 41.3 0.59x 0.47 0.26w 0.15 4.83w 0.53 6.37 1.9z 3.2 24.1z 0.7z 2.9z
— — — 3.9 0.04 0.05 0.02 0.02 0.51 0.03 0.89 0.05 0.41 2.1 0.08 0.18
a
Gain divided by starter plus milk replacer intake. Milk replacer intake from 0 to 6 wk when it was fed averaged 0.44 kg for the group fed 0.45 kg MR, 0.65 kg for the group fed 0.68 kg MR, and .74 kg for the group fed 0.77 kg MR. b Fecal scores: 1 = normal, thick in consistency; 2 = normal, but less thick; 3 = abnormally thin but not watery; 4 = watery; 5 = watery with abnormal coloring. Abnormal fecal scores were days with scores > 2. c 1 to 5 system with 1 = emaciated and 5 = obese. wx Means with different superscripts differ (P < 0.05). yz Means with different superscripts differ (P < 0.1).
20% fat MR was reported to increase BW gain by 55%, as well as efficiency, but slightly decrease starter intake (Hill et al., 2006). Bartlett et al. (2006) reported that lactose is utilized better than fat in calves that were not introduced to the experimental treatments until after a high fat, pre-trial MR was fed for 3 wk with no starter being fed. Tikofsky et al. (2001) suggested that feeding approximately 1 kg of a 23.5% CP, 14.7% fat MR (with no starter fed) was optimum in calves that were not weaned based on observations that the greater fat MR resulted in more fat deposition but similar protein deposition. Thus, optimum CP concentration might be around 23%, and fat at more than 15% would likely result in fat gain but not CP gain. Hill et al. (2006) observed depressed starter intake when a 28% CP, 20% fat MR was fed at
0.68 kg daily and suggested that a fat level of less than 20% might be required to avoid depressing starter intake. Considering these observations, MR fed at 0.68 kg daily containing from 22 to 28% CP (Trial 1) and 11 to 17% fat (Trial 2) were evaluated. Our MR treatments were not formulated or fed to be isocaloric like in trials of Tikofsky et al. (2001), Bartlett et al. (2006), and Blome et al. (2003). Additionally, some of our fat concentrations were less than the least concentrations fed in MR of Tikofsky et al. (2001; 14.7% fat) and Bartlett et al. (2006; 19% fat). In Trials 1 and 2, it was evident that both the concentration of CP and fat in the MR fed at 0.68 kg daily affected calf performance. Increasing the CP in the MR fed at 0.68 kg daily increased BW gains up to 26% CP. In Trial 3, the calves fed 0.68 kg of the MR containing 26 and 28% CP had
similar performance. In Trial 2, calf gain increased linearly from 11 to 17% fat in the MR fed at 0.68 kg/d. In retrospect, a concentration of fat greater than 17% should have been included; however, calves fed 0.68 kg of the 20% fat MR did not perform better than calves fed the 17% fat MR in Trial 3. Fat may be important in the early weeks of a calf’s life beyond influencing daily gain. Heat production has been shown to decrease with age and increase with stress and declining environmental temperatures in calves less than 2 wk of age (Schrama et al., 1995a,b, 1996). The slight conflict between our observations and the results of Bartlett et al. (2006) is likely explained by the age of their calves vs. calves in Trial 2. They used calves that were introduced to the experimental treatments at approximately 3 wk of age, after whole milk was fed
380
during a pre-trial period. A high-fat MR may be utilized better during the first few weeks of a calf’s life (Trial 2), and a high-lactose, low-fat MR may be utilized better thereafter (Bartlett et al., 2006). However, it is important to consider that a 2-phase MR program (a high-fat MR, followed by a lower fat MR) would complicate feeding management and may be impractical on many operations. Results from Trial 3 confirmed that 26% CP and 17% fat are near optimum for a MR fed at 0.68 kg daily. The calves fed the 3 MR with combinations of 1) 28% CP, 20% fat, 2) 28% CP, 17% fat, and 3) 26% CP, 20% fat did not improve performance (statistically or numerically) compared to calves fed the 26% CP, 17% fat MR. Consistent with our data, Ballard et al. (2002) reported a greater intake of starter, greater BW gains, and greater increase in BCS, and a trend for the calves to be taller, longer, and of larger girth when they fed a 27% CP MR with 15 vs. 20% fat. The calves fed the 26% CP, 17% fat MR at 0.68 and 0.77 kg daily performed similarly (P > 0.1). Quigley et al. (2006) reported depressed starter intake and increased scouring and mortality when feeding 0.9 kg of a 28% CP, 15% fat MR. Our observations suggest that 0.68 to 0.77 kg of MR fed daily is near the maximum amount to feed without increasing the risk of health problems. Post-weaning performance did not differ for any treatment in Trial 1, 2, or 3. This is important to note because in past trials calves fed high levels of milk or MR typically have lesser BW gains (Bar-Peled et al., 1997; Jasper and Weary, 2002; Hill et al., 2006), lesser starter intakes, and poorer feed efficiencies at weaning time and post-weaning (Strzetelski et al., 2001; Jasper and Weary, 2002; Hill et al., 2006). It is difficult to fully discern differences between our current trial and previously published trials. Diaz et al. (2001) and our current trials used calves that were less than 1 wk old,
Hill et al.
whereas Blome et al. (2003) and Bartlett et al. (2006) used calves that were over 2 wk old. Based on our review of the literature, we believe that we were the only researchers to feed starter and to castrate, dehorn, and wean the calves when multiple amounts of nutrients were fed over a control. In Trial 1, the calves fed 0.68 kg of 26% CP, 13% fat MR averaged 56 kg BW and consumed 1.06 kg DM, 0.26 kg CP, 4.55 Mcal DE, and gained 0.63 kg BW daily. In Trial 2, the calves fed 0.68 kg of 24% CP, 17% fat MR averaged 55 kg BW and consumed 1.02 kg DM, 0.24 kg CP, 4.53 Mcal DE, and gained 0.63 kg BW daily. In Trial 3, the calves fed 0.68 kg of 26% CP, 17% fat MR averaged 54 kg BW and consumed 1.08 kg DM, 0.26 kg CP, 4.75 Mcal DE, and gained 0.61 kg BW daily. Equations in the NRC (2001) suggest approximately 1.0 kg DM, 0.22 kg CP, and 4.4 Mcal DE daily is required to support these ADG in 55-kg BW calves when both MR and starter is fed. Based on the performance of calves in Trials 1 and 3, their requirement for CP was approximately 18% more (0.26 vs. 0.22 kg CP/d) than suggested by NRC 2001. However, the requirement for DE of the calves in Trials 1, 2, and 3 were approximately 5% more than suggested by NRC 2001. The groups of calves fed the least MR (both on DM basis: 31.2% CP, 20.0% fat, 96% DM) in Diaz et al. (2001) were most similar to our calves. These calves averaged 55 and 56 kg BW, consumed 0.8 and 1.2 kg of MR DM (no starter), 0.24 and 0.35 kg CP, 3.86 and 6.04 Mcal DE, and gained 0.52 and 0.94 kg BW daily. Their calves fed 0.8 kg of MR may have been limited by energy intake. The fastest growing calves in trial of Blome et al. (2003) averaged 58 kg BW, consumed 0.8 kg (DM basis: 25.8% CP, 18.6% fat, 97% DM) of MR DM (no starter), 0.21 kg CP, 4.01 Mcal DE, and gained 0.62 kg BW daily. The fastest growing calves in the trial of Bartlett et al. (2006) averaged 57 and 58 kg, consumed 0.96 kg (DM basis: 22.3% CP, 21.4% fat, 97%
DM) and 0.99 kg (DM basis: 24.8% CP, 18.9% fat, 97% DM) of MR DM (no starter), 0.22 and 0.25 kg of CP, 4.74 and 4.87 Mcal DE and gained 0.69 and 0.70 kg BW daily, respectively. Our calves may have required more energy and CP than calves in the other trials because we fed starter, castrated, dehorned, and weaned the calves. Additionally, our calves were multiple-source calves that were transported approximately 10 h to our research nursery. Efficiency of nutrient use decreases and requirements estimated from the NRC 2001 when starter and MR are fed vs. MR alone increase. A similar situation may occur when normal management practices are carried out on milk-fed calves. Alternatively, an allowance could be made to increase maintenance requirements of the calf to allow for increased energy and protein needs from stress associated with normal management practices. Even with the variation in initial calf age (< 1 to > 3 wk), management (dehorning, castrastion), and diet (starter fed or not fed) among published trials of Diaz et al. (2001), Blome et al. (2003), Bartlett et al. (2006), and our trials, estimates of CP and energy requirements to support 0.6 to 0.7 kg/d of BW gain were within approximately 20% of each other and equations of the NRC (2001).
Implications Feeding 0.68 kg of a 26% CP, 17% fat MR to neonatal calves less than 8 wk of age fed starter appeared near optimum. Additionally, this MR composition and rate did not have a negative effect on starter intake, efficiency, and post-weaning performance compared to the control 20% CP, 20% fat MR fed at 0.45 kg daily. The amounts of MR fed did not have to be changed with age of the calf, fecal scores and health issues were not perturbed, and overall management needs were not increased relative to the control MR. Research in calves less than 8 wk of age is needed on amino acids rather than CP and spe-
Feeding Rate and Composition of Milk Replacers
cific fatty acids rather than fat or energy requirements because these data are not available. More research is needed to determine the effects MR rates exceeding 0.68 kg daily on early post-weaning growth to minimize the growth slumps frequently reported.
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