Serum Protein and DMI
Total serum proteins indicated adequate passive immunity transfer (
Table 2) by exceeding the 5.2 g/dL recommended by
Tyler et al., 1996- Tyler J.W.
- Hancock D.D.
- Parish S.M.
- Rea D.E.
- Besser T.E.
- Sanders S.G.
- Wilson L.K.
Evaluation of 3 assays for failure of passive transfer in calves..
. No MR × FR interactions (
P > 0.10) were detected for intake of MR and CS (
Table 2). The MR main effects for MR, CS, and total DMI were similar (
P > 0.10) for calves fed both MR, whereas calves fed MR at higher FR demonstrated greater (
P < 0.05) MR intakes during all study time periods. However, calves fed higher MR FR had lower (
P < 0.05) CS intake during several study time periods and total CS intake for the study (d 1 to 42 and d 1 to 56). Total DMI during selected time periods were greater (
P < 0.05) for calves fed MR at greater FR. Calves fed the lower CP MR had greater (
P < 0.01) CS intake d 1 to 42 compared with calves fed the HP MR. Intakes of CS during d 1 to 56 were greater (
P = 0.03) for calves fed CP1 compared with calves fed the CP2, with calves fed HP1 and HP2 being intermediate. The total DMI (kg/d) for d 1 to 56 were similar for calves fed all treatments (
Table 2).
Table 2Milk replacer (MR), calf starter (CS), and DMI for calves fed MR with 2 protein concentrations at 2 feeding rates (FR)
BW, Growth, Feed Efficiency, and Hip Height Measurements
Calves entered the study at an averaging age of 3 d. The initial mean BW of all calves was 39.6 ± 0.74 kg (
Table 3). There were no MR × FR interactions (
P > 0.10) detected for all parameters measured in this study, except for 2 (G:F and g of CP/Mcal of ME), which exhibited a MR × FR interaction trend (
P ≤ 0.10), which will be discussed later. No differences (
P > 0.10) were found for overall BW, BW gain, ADG, and hip height gain. Calves fed at the higher FR tended (
P < 0.06) to have greater BW on d 14 and 28, but after d 28, BW were similar (
P > 0.10) for calves fed at both FR (
Table 3). The ADG (kg/d) were improved (
P < 0.06) in specific periods by MR FR, but for the overall study, the MR × FR resulted in similar (
P > 0.10) ADG. During this time, calves were being fed 1×/d starting on d 36 and calves fed the lower FR were eating more CS during this time period. Calves fed MR at the lower FR consumed more CS throughout the whole study, which would have improved transition during the weaning phase, having less stress, resulting in better BW gains during that time period. The ADG from 1 to 56 d were similar (
P > 0.10) for calves fed both MR at both FR.
Table 3Body weight, ADG, G:F, and hip height (HH) measurements for calves fed milk replacer (MR) with 2 protein concentrations at 2 feeding rates (FR)
a,bMeans within a row with different superscripts differ (P < 0.05).
Hip heights were similar (
P > 0.10) for calves fed both MR at both FR. There was a trend (
P ≤ 0.10) for an interaction of MR × FR from d 43 to 56 for feed efficiency as calves fed CP2 tended (
P < 0.10) to have greater feed efficiency (G:F) than calves fed the other treatments. Overall, feed efficiency was greatest (
P < 0.01) for calves fed the higher MR FR (i.e., CP2 and HP2). The lack of a MR × FR interaction for many parameters measured in this study was not expected. Reasons for this could be that calves fed the higher FR had greater energy intake from the added calories supplied by the increased amounts of MR powder, which resulted in a lower CS for calves fed a lower MR FR. Basically, MR DMI is replacing CS DMI, which has implications for slowing ruminal development. The reduction in CS intake has been observed in many studies (
Terre et al., 2007- Terre M.
- Devant M.
- Bach A.
Effect of level of milk replacer fed to Holstein calves on performance during the preweaning period and starter digestibility at weaning..
;
Hill et al., 2009- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effects of fat concentration of a high protein milk replacer on calf performance..
,
Hill et al., 2010- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effect of milk replacer program on digestion of nutrients in dairy calves..
). Terré et al. (2007) reported that calves fed relatively large amounts of MR (up to 1,260 g of DM/d) had lower DM and NDF digestibilities compared with calves fed low amounts of MR (up to 500 g of DM/d) during the week after weaning. More recently,
Hill et al., 2010- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effect of milk replacer program on digestion of nutrients in dairy calves..
reported similar findings when comparing MR allowances of 0.66 versus 1.09 kg of MR/d. Even though calves on the higher MR FR treatments consumed less CS, they had greater overall ADG.
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding rate and concentrations of protein and fat of milk replacers fed to neonatal calves..
observed that a 27% CP, 17% fat MR powder fed at 0.66 kg of DM/d has been successful at improving ADG while maintaining CS intake compared with a 21% CP, 21% fat MR fed at 0.44 kg of DM/d. However, the previous program discussed by
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding rate and concentrations of protein and fat of milk replacers fed to neonatal calves..
does not maximize ADG during the first month of life but does maximize ADG during the second and third months of life (
Hill et al., 2007- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effects of feeding rate of milk replacers and bedding material for calves in a cold naturally ventilated nursery..
). This would suggest that calves fed the HP2 treatment would potentially have improved growth rates (fed at a higher rate than
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period..
, 28:17), even though these calves consume lesser amounts of CS compared with the calves fed other treatments because these calves had the greatest ADG. This would demonstrate that calves fed HP2 did not experience the postweaning slump that is commonly observed when feeding accelerated MR feeding programs (
Bar-Peled et al., 1997- Bar-Peled U.
- Robinzon B.
- Maltz E.
- Tagari H.
- Folman Y.
- Bruckental I.
- Voet H.
- Gacitua H.
- Lehrer A.R.
Increased weight gain and effects on production parameters of Holstein heifer calves that were allowed to suckle from birth to six weeks of age..
;
;
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period..
).
Differences in growth rates during the 14-d periods (
Table 3) do lead to speculation that ADG increases could potentially be due to gut fill, gut tissue growth, growth composition (fat vs. protein/bone), or water intake associated with differences in MR and CS intakes.
Cowles et al., 2006- Cowles K.E.
- White R.A.
- Whitehouse M.L.
- Erickson P.S.
Growth characteristics of calves fed an intensified milk replacer regimen with additional lactoferrin..
evaluated the effect of lactoferrin addition to MR varying in CP on DMI, growth, and days medicated. Holstein heifer calves were assigned to 4 treatments including 562 g daily of a nonmedicated conventional MR (20% CP:20% fat) feeding regimen with or without 1 g of supplemental bovine lactoferrin or a nonmedicated intensified MR feeding regimen (0.2 Mcal/kg of BW
0.75 d 2 to 9 and 0.27 Mcal/kg of BW
0.75 d 10 to 42) with or without 1 g of supplemental bovine lactoferrin (n = 8 for both treatments). Calves were fed pelleted CS beginning on d 2 and had free choice access to water. Calves remained on the study for 14 d after weaning. Calves on conventional treatments ate more CS before weaning, during weaning, and after weaning. Before weaning, intensively fed calves had higher DMI. Weights of intensively fed calves were greater at weaning. Intensified MR-fed calves had greater ADG before weaning and overall and higher G:F ratios before weaning, but conventionally fed calves had higher G:F ratios during weaning. Intensified MR-fed calves had greater hip heights during weaning and after weaning and greater heart girths before weaning, during weaning, and after weaning. An intensified MR feeding regimen promotes faster growth during the preweaning period when compared with calves fed conventional treatments, but supplemental bovine lactoferrin was not beneficial under these experimental conditions.
How do different feeding regimens affect body composition?
Chapman et al., 2017- Chapman C.E.
- Stone Wilkinson P.
- Murphy M.R.
- Erickson P.S.
Technical note: Evaluating nuclear magnetic resonance spectroscopy for determining body composition in Holstein dairy calves using deuterium oxide dilution methods..
developed a simple technique to determine body composition in Holstein dairy calves using deuterium dilution methods. Calves were assigned to 1 of 3 treatments: (1) 446 g of DM of a conventional MR (20% CP, 20% fat), (2) 669 g of DM of a moderately high protein MR (26% CP, 18% fat), or (3) 892 g of DM of a moderately high protein MR (26% CP, 18% fat). Free-choice water and CS were fed. After weaning, a series of blood samples was taken after injections of deuterium oxide. No differences were detected in total body water, protein, fat, or mineral content in calves fed the different MR, which provides an interesting perspective.
Gelsinger et al., 2016- Gelsinger S.L.
- Heinrichs A.J.
- Jones C.M.
A meta-analysis of the effects of preweaned calf nutrition and growth on first-lactation performance..
conducted a meta-analysis based on several studies following previous work that proposed that increased feeding of milk or MR to neonatal calves may improve subsequent milk production. However, data from individual studies are conflicting, and the previous meta-analysis was unable to assess the influence of CS intake. The current meta-analysis was to review newly published data and evaluate the effects of preweaning diet (including CS intake) and growth rate on first-lactation milk, fat, and protein yield. The differences in preweaning ADG are small and account for less than 3% of the variation in first-lactation milk production. Genetics, health, and other farm-management practices will account for 97% of the actual milk production that was observed. Furthermore, any ADG improvement to be accomplish in preweaned calves is far more economically accomplished by increasing CS intakes in combination with a reasonable milk or MR program. These authors found a synergistic relationship between preweaning liquid and CS DMI for improving milk, fat, and protein production, and a positive relationship between first-lactation performance and preweaning ADG. These data indicated that provision of adequate nutrients from liquid and solid feeds and maintaining ADG above 0.5 kg/d can enhance first-lactation heifer performance when combined with proper postweaning practices. In the current study, calves gained at least 0.5 kg/d across treatments.
Further support was developed by
Chester-Jones et al., 2017- Chester-Jones H.
- Heins B.J.
- Ziegler D.
- Schimek D.
- Schuling S.
- Ziegler B.
- Ondarza M.B.
- Sniffen C.J.
- Broadwater N.
Relationships between early-life growth, intake, and birth season with first-lactation performance of Holstein dairy cows..
, who reported the relationships between early-life parameters (including ADG, BW, MR intake, CS intake, and birth season) and the first-lactation performance of Holstein cows. Data were collected from birth years 2004 to 2012, resulting in 2,880 Holstein heifer observations. Calves were received from 3 commercial dairy farms and enrolled in 37 different calf research trials at the University of Minnesota SROC from 3 to 195 d. Upon trial completion, calves were returned to their respective farms. Milk replacer studies evaluated varying protein levels and amounts fed, but for the majority of studies, calves were fed a MR containing 20% CP and 20% fat at 0.57 kg/d. Most calves (93%) were weaned at 6 wk. The ADG at 6 wk resulted in increased first-lactation milk and milk component yields. Intake of CS at 8 wk had a significant positive relationship with first-lactation 305-d yield of milk and milk components. Milk replacer intake, which varied very little in this data set, had no effect on first-lactation 305-d yield of milk and milk components.
Calculation Results of Protein-to-Energy Ratio
The intake data were used to calculate the CP and energy intake and the ratio of CP to ME for calves fed all treatments in relationship to ADG (
Table 4). No MR by FR interactions were detected (
P > 0.10), except for a tendency (
P < 0.10) for a MR by FR interaction when evaluating the CP/ME ratio for the overall d 1 to 56 study, whereas other time periods were similar (
P > 0.10). Per the experimental design, the MR CP content increased (
P < 0.05) CP intake and CP/ME ratio for calves fed 24% CP MR compared with calves fed the 20% CP MR for the time period d 1 to 42. Calves fed the greater MR FR demonstrated greater (
P < 0.05) ME intakes with a lower CP/ME ratio compared with calves fed the lower MR FR for 1 to 42 d. For the time period, 43 to 56 d, no differences (
P > 0.10) were observed for calves for intake of CP, ME, and the ratio of CP/ME, which indicates no effect of the MR feeding stage on postweaning performance. The tendency (
P < 0.10) for a MR by FR interaction for the time period d 1 to 56 for the CP/ME ratio indicated that calves fed CP2 demonstrated the lowest (
P < 0.05) CP/ME ratio, whereas calves fed HP1 demonstrated the greatest (
P < 0.05) ratio of CP/ME, with the remaining treatments being intermediate and different (
P < 0.05). Adjusting the CP concentration, MR FR, or both can influence the ratio of CP/ME to potentially improved calf growth performance.
Table 4Protein and energy intake by treatment for calves fed milk replacer (MR) with 2 protein concentrations at 2 feeding rates (FR)
a–dMeans within a row with different superscripts differ (P < 0.05).
The protein:energy ratio is a fundamental concept for determining DMI, ADG, composition of gain, and body composition. The protein requirement for maintenance is relatively low, but the requirement for gain is relatively high (
).
noted that the opposite is true for energy and that the composition of protein and energy can affect calf performance. The current
NRC, 2001Nutrient Requirements of Dairy Cattle.
publication illustrates this. For example, a 60-kg calf consuming 1.04 kg of DM/d and gaining 600 g requires 217 g of CP and 4.31 Mcal of ME for a CP:ME ratio of 50.4 CP:Mcal of ME. A 60-kg calf consuming 1.24 kg of DM and gaining 800 g/d requires 275 g of CP and 5.16 ME for a CP:ME ratio of 53.3. Postweaned calves of 70 kg of BW gaining 500 g/d with 1.54 kg of DMI require a CP:ME of 55.5. The same BW heifer consuming 2.03 kg of DMI and gaining 800 g/d requires a CP:ME ratio of 58.4. The efficiency of ME for maintenance is higher than the efficiency for gain (
NRC, 2001Nutrient Requirements of Dairy Cattle.
). This was supported by
Brown et al., 2005- Brown E.G.
- VandeHaar M.J.
- Daniels K.M.
- Liesman J.S.
- Chapin L.T.
- Keisler D.H.
- Weber M.S.
Effect of increasing energy and protein intake on body growth and carcass composition of heifer calves..
, who observed that increasing energy and protein intake from 2 to 8 wk and 8 to 14 wk of age increased BW, rate of growth, frame size, and G:F ratio but did not alter carcass composition.
Recent studies by
Hill et al., 2009- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effect of consistency of nutrient intake from milk and milk replacer on dairy calf performance..
,
Hill et al., 2009- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effects of fat concentration of a high protein milk replacer on calf performance..
) predicted the preweaning CP and energy requirements for calves fed solely MR are approximately 51 to 55 g of CP/Mcal of ME when calves are weaned at 28 d. They also emphasized the importance of maintaining Lys, Met, and Thr AA balances. The predicted CP/ME ratio requirements for MR up to weaning of 51 to 55 g of CP/Mcal of ME were met or exceeded using the treatments in this study; however, our calculations include both MR and CS.
Hill et al., 2009- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effect of consistency of nutrient intake from milk and milk replacer on dairy calf performance..
,
Hill et al., 2009- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effects of fat concentration of a high protein milk replacer on calf performance..
) recommended a calf CP/ME ratio before weaning of 51 to 55 g of CP/Mcal of ME. Our data preweaning (42 d) ranged from 51.4 to 59.9 g of CP:Mcal of ME (
Table 5). Our data overall for the 56-d study ranged from a CP/ME of 67.4 to 71.4, with the best growth performance occurring at a ratio of 67.4 g of CP/Mcal of ME being higher than those of
Hill et al., 2009- Hill T.M.
- Bateman II, H.G.
- Aldrich J.M.
- Schlotterbeck R.L.
Effects of fat concentration of a high protein milk replacer on calf performance..
when combining both MR and CS.
Table 5Health data for calves fed milk replacer (MR) with 2 protein concentrations at 2 feeding rates (FR)
Health Performance
No differences (
P > 0.10) were detected for the MR by FR interaction and the main effects of MR and FR for total serum protein, fecal scores, scouring days, and treatment costs (
Table 5). There was a difference (
P < 0.05) for the FR main effect in that calves fed higher MR FR compared with calves fed low MR FR had higher fecal scores, number of days scouring with a score equal to or greater than 3, and treatment costs for the overall periods of 1 to 42 d.
Fecal scores and scouring days were increased (
P < 0.01) when calves were fed both MR at greater FR (
Table 5) for the first 14 d and the d 1 to 42 and d 1 to 56 time periods. Greater fecal scores and scouring days were observed by
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period..
,b).
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period..
reported that calves fed a 28% CP and 20% fat MR had an average fecal score of 1.88 compared with calves fed 20% CP and 20% fat MR, having an average fecal score of 1.57, with the average scouring days being 5.74 and 3.22, respectively.
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding calves different rates and protein concentrations of twenty percent fat milk replacers on growth during the neonatal period..
observed the same responses when comparing 2 FR of 2 MR containing either 20% CP and 20% fat or 28% CP and 20% fat with the 20:20 MR fed at the same rate as the 28:20 MR. Average fecal scores were 1.42, 1.50, and 1.60 and average scouring days were 3.65, 4.11, and 4.23 for 20:20 MR fed at 0.45 kg/d, 20:20 MR fed at 0.68 kg/d, and 28:20 MR fed at 0.68 kg/d, respectfully.
Hill et al., 2006- Hill T.M.
- Aldrich J.M.
- Schlotterbeck R.L.
- Bateman II, H.G.
Effects of feeding rate and concentrations of protein and fat of milk replacers fed to neonatal calves..
reported that the scouring days varied from 2.4 to 3.3. A minimal number of calves were used (10 per treatment) in that study, but the results do support the results found in this study, that feeding MR at higher FR does increase fecal scores and scouring days.