Intestinal adaptations to energy source of milk replacer in neonatal dairy calves

Incremental supply of fat, lactose, or protein influences the diurnal pattern of heat production and substrate oxidation in pre-weaning calves

Increasing nutrient supply to dairy calves has well known benefits; however, the effects of milk replacer (MR) composition when supplied in higher amounts are not fully understood, particularly in the first weeks of life. To better understand the metabolism of macronutrient supply in young calves (21 d old), we investigated diurnal patterns of heat production and substrate oxidation in young calves fed MR with an incremental supply of fat, lactose, or protein. Thirty-two groups of 3 mixed-sex Holstein-Friesian newborn calves (3.4 ± 1.6 d of age), were randomly assigned to one of 4 dietary treatments and studied for 21 d. Diets consisted of a basal MR (23.3% CP, 21.2% EE, and 48.8% lactose of DM) fed at 550 kJ/kg BW0.85 per day (CON; n = 24), or the basal MR incrementally supplied with 126 kJ of DE/BW0.85 per day as milk fat (+FAT; n = 23), lactose (+LAC; n = 24), or milk protein (+PRO; n = 23). Calves were fed MR in 2 daily meals and had ad libitum access to water, but were not supplied with any calf starter nor forage. After 2 weeks of adaptation to the diets, groups of 3 calves were placed for 1 week in an open-circuit respiration chamber for nitrogen and energy balance measurements (lasting 7 d). On d 3, glucose oxidation kinetics was estimated by using [U-13C]glucose. Measurements included total heat production (total energy [HP], activity [Hact] expenditure, resting metabolic rate [RMR]), respiration quotient (RQ), carbohydrate (COX) and fat oxidation (FOX) in 10 min. intervals and averaging these values per hour over days. Incremental supply of lactose and fat increased body fat deposition, with observed patterns in RMR indicating that this increase occurred primarily after the meals. Specifically, the average daily RMR was highest in the +PRO group and lowest in the CON treatment. The HP was higher in the +PRO group and throughout the day, hourly means of HP were higher in this treatment mainly caused by an increase in Hact. The recovery of 13CO2 from oral pulse-dosed [U-13C]glucose was high (77%), and not significantly different between treatments, indicating that ingested lactose was oxidized to a similar extent across treatments. Increasing lactose supply in young calves increased fat retention by reduction in fatty oxidation. Calves fed a MR with additional protein or fat raised RMR persistently throughout the day, while extra lactose supply only affects RMR after the meal. Dietary glucose was almost completely oxidized (77% based on (13C) glucose measurement) regardless of nutrient supplementation. Extra protein supply increased HP and FOX compared with similar intakes of fat and lactose. Fasting heat production (FHP) of young, group-housed calves is comparable to literature values and unaffected by energy intake. Overall, these findings deepen our understanding of how different nutrients impact metabolic processes, fat retention, and energy expenditure in young dairy calves.

Fat composition of milk replacer influences postprandial and oxidative metabolisms in dairy calves fed twice daily

Milk replacers (MR) for calves contain alternative fat sources as substitute for milk fat. This substitution leads to differences in fat properties, such as the fatty acid profile and the triglyceride structure. This study evaluated how fat composition in MR affects gastrointestinal health, blood redox parameters, and postprandial metabolism in calves fed twice daily. Forty-five individually housed male Holstein-Friesian calves (2.3 ± 0.85 d of age) were assigned to 1 of 15 blocks based on the age and the day of arrival. Within each block, calves were randomly assigned to 1 of 3 experimental diets and received their respective diet from arrival until 35 d after arrival. The 3 experimental diets (n = 15 per treatment group) consisted of an MR with a blend of vegetable fats containing rapeseed and coconut (VG), an MR with only animal fats from lard and dairy cream (AN), and an MR containing a mixture of animal and vegetable fats including lard and coconut (MX). The fatty acid profile of each MR was formulated to resemble that of bovine milk fat while using only 2 fat sources. All MR were isoenergetic, with 30% fat (% DM), 24% crude protein, and 36% lactose. Chopped straw and water were available ad libitum from arrival onward but no starter feed was provided. Daily milk allowances were 6.0 L from d 1 to 5, 7.0 L from d 6 to 9, and 8.0 L from d 10 to 35, divided into 2 equal meals and prepared at 135 g/L (13.5% solids). Fecal appearance was scored daily; calves were weighed and blood was drawn on arrival and weekly thereafter. Urine and feces were collected over a 24-h period at wk 3 and 5 to determine apparent total-tract digestibility and assess gastrointestinal permeability using indigestible markers. Postprandial metabolism was evaluated at wk 4 by sequential blood sampling over 7.5 h, and the abomasal emptying rate was determined by acetaminophen appearance in blood. Fat composition in MR did not affect growth, MR intake, gastrointestinal permeability, nor nutrient digestibility. The percentage of calves with abnormal fecal scores was lower at wk 2 after arrival in calves fed VG than MX, whereas AN did not differ from the other treatments. Calves fed AN and MX had higher thiobarbituric acid reactive substances measured in serum than VG, whereas plasma ferric-reducing ability was greater in calves fed MX than VG. Postprandial acetaminophen concentrations did not differ across treatment groups, but the area under the curve was smaller in calves fed VG than in the other 2 treatments, which is indicative of a slower abomasal emptying. Postprandial serum triglyceride concentration was greater in calves fed AN than VG, whereas MX did not differ from the other treatments. Based on these outcomes, all 3 fat blends can be considered suitable for inclusion in MR for calves.

Evaluation of bovine colostrum replacer supplementation to improve weaning transition in Holstein dairy calves

The objective of this randomized controlled trial was to evaluate the efficacy of supplementing bovine colostrum replacer during weaning to reduce intestinal permeability and improve gain. For this experiment, 65 calves were enrolled and housed individually until 70 d of age. Calves were fed milk replacer (150 g/L) 3 times daily with 9 L/d, 10.5 L/d, 11.25 L/d, and 12 L/d offered from d 1-7, d 8-14, d 15-21, d 22-56, respectively. Calves were weaned over 8 d from d 57-64, receiving a total of 7.8 L in 2 meals/d from d 57-60 and 3.8 L/d in one feeding from d 61-64. At d 57, calves were blocked by birth weight and randomly assigned to one of 2 treatments, equal in metabolizable energy, which were fed once daily during weaning from d 57-64: control (CON; n = 31 calves): 3.8 L milk replacer (150 g/L) fed by nipple bottle, or colostrum supplementation (COL; n = 34): a mixture of 1 L bovine colostrum replacer (125 g/L) and 3 L milk replacer (150 g/L) with 3.8 L of the mixture fed by nipple bottle. Serum IgG was measured within 48 h of birth and body weight was taken at d 0, 57, 60, 64, 70, 77, and 84. Starter intake and bovine respiratory disease (BRD) score were measured daily from d 50-70 and fecal consistency was examined daily from d 56-70. Serum β-hydroxybutyrate (BHB) and lung consolidation were evaluated at d 57, 64, and 70 and intestinal permeability was assessed by recovery of chromium-EDTA, lactulose, and d-mannitol from plasma after oral administration at d 56 and 65. There was no difference in body weight between treatment groups at the start of weaning, but COL were 2.79 kg (95% CI: 0.90-4.68) and 2.76 kg (95% CI: 0.86-4.65) heavier than CON at d 77 and 84, respectively. Additionally, COL tended to gain 100.00 g/d more than CON calves (95% CI: -10.41-207.13) from d 57-84. There were no differences in any of the other variables measured. Supplementation of bovine colostrum replacer during weaning may improve weight gain, but the mechanism of action is not clear.

Postprandial metabolism and gut permeability in calves fed milk replacer with different macronutrient profiles or a whole milk powder

Significant differences exist in the composition of current milk replacers (MR) and bovine whole milk. This study investigated how the macronutrient profile of 3 different MR formulations containing varying amounts of fat, lactose, and protein, and a whole milk powder (WP), affect postprandial metabolism and gut permeability in male Holstein calves. Sixty-four calves (45.4 ± 4.19 kg [mean ± SD] and 1.8 ± 0.62 d of age) were blocked in order of arrival to the facility and within each block, calves were randomly assigned to 1 of 4 treatments. Treatments included a high-fat MR (HF: 25.0% dry matter [DM] fat, 22.5% protein, 38.6% lactose; n = 14), a high-lactose MR (HL: 44.6% lactose, 22.5% protein, 18.0% fat; n = 17), a high-protein MR (HP: 26.0% protein, 18.0% fat, 41.5% lactose; n = 17), and WP (26.0% fat, 24.5% protein, 38.0% lactose; n = 16). Calves were fed 3.0 L (135 g/L) 3 times daily at 0600, 1200, and 1800 h with a teat bucket. Milk intake was recorded daily for the first 28 d after arrival, and blood sampling and body weight measurements were performed at arrival and on d 7, 14, 21, and 27. Gut permeability was estimated from fractional urinary excretion of indigestible markers (Cr-EDTA, lactulose, and d-mannitol) administered as a single dose on d 21 instead of the morning milk meal. Digestibility was determined simultaneously from a total collection of feces over 24 h. Postprandial dynamics were measured on d 28 by sequential blood sampling over 7.5 h. Dry matter intake of MR over 28 d was slightly greater in calves fed HL and HP than in WP. Recovery of Cr-EDTA and d-mannitol over a 24-h urine collection was greater in calves fed WP and HP than HL calves. Apparent total-tract digestibility of crude ash, protein, and fat did not differ among treatments; however, DM digestibility was lower in calves fed WP than in other treatment groups. In addition, abomasal emptying, as indicated by the area under the curve (AUC) for acetaminophen, was slower in calves fed WP than in calves fed HF and HL. The AUC for postprandial plasma glucose was lower in calves fed HL than WP and HF and lower in calves fed HP than WP. The AUC for postprandial serum insulin was greater in calves fed HP than WP and HF, whereas calves fed HL did not differ from the other treatments. Postprandial triglycerides were greater in calves fed WP, and postprandial adiponectin was higher in calves fed HL than other treatments. The high content of lactose and protein in MR had a major effect on postprandial metabolism. This raises the possibility of optimizing MR formulations to maintain metabolic homeostasis and influence development.

Water, mineral, and blood acid-base balance in calves with naturally occurring diarrhea receiving two alternative oral rehydration solutions or a placebo

Quantifying the water and mineral losses in feces is essential to determine the optimal composition of oral rehydration solutions (ORS) for diarrheic animals. In a randomized complete block design, this study evaluated water, mineral, and blood acid-base balance of calves with naturally occurring diarrhea receiving ORS or a placebo. On d 0, 45 calves (age: 18 ± 3.2 d; mean ± SD) were selected based on the presence of visual signs of diarrhea, such as dirty tail or wet feces, along with clinical symptoms evaluated by measuring the skin turgor and the degree of enophthalmos. On d 1, calves were divided into blocks of 3 animals based on blood base excess (BE) measured at 0900 h, and within each block, calves were randomly assigned to 1 of 3 treatments (15 calves per treatment) including (1) a hypertonic ORS (HYPER; Na+ = 110 mmol/L; 370 mOsm/kg; strong ion difference [SID] = 60 mEq/L), (2) a hypotonic ORS with low Na+ (HYPO; Na+ = 77 mmol/L; 278 mOsm/kg; SID = 71 mEq/L), and (3) a placebo consisting of lukewarm water with 5 g/L of whey powder (CON). Milk replacer (MR) was fed through teat buckets twice daily at 0630 h and 1700 h in 2 equally sized meals of 2.5 L from d 1 to 3 and of 3.0 L on d 4 and 5. Treatments consisting of 2.0 L lukewarm solutions were administered between milk meals from d 1 to 3 at 1200 h and 2030 h through teat buckets. Refusals of MR and treatments were recorded daily, and blood samples were collected from the jugular vein once daily at arrival in the afternoon of d 0 and at 0900 h from d 1 to 5 after arrival. Urine and feces were collected quantitatively over a 48-h period from 1200 h on d 1 to 1200 h on d 3, and a representative sample of each 24-h period was stored. In addition, the volume of extracellular fluid was evaluated on d 2 by postprandial sampling over a 4-h period relative to the injection of sodium thiosulfate at 1300 h. Total daily fluid intake (MR, treatment, and water) from d 1 to 3 was greater in HYPER (LSM ± SEM; 8.9 ± 0.36 L/d) and HYPO (7.8 ± 0.34 L/d) than in CON (6.6 ± 0.34 L/d). This resulted in a greater water balance (water intake - fluid output in urine and feces) in calves receiving ORS (59.6 ± 6.28 g/kg BW per 24 h vs. 39.6 ± 6.08 g/kg BW per 24 h). Fecal Na+ losses were greater in HYPER than in the other treatments (81 ± 12.0 mg/kg BW per 24 h vs. 24 ± 11.8 mg/kg BW per 24 h). Blood pH was higher in HYPO (7.41 ± 0.016) than CON (7.35 ± 0.016) over the 5 monitoring days, whereas HYPER (7.37 ± 0.017) did not differ with other treatments. In this experimental model, diarrheic calves were likely unable to absorb the high Na+ load from HYPER, resulting in greater Na+ losses in feces, which might have impaired the alkalinizing capacity of HYPER. In contrast, HYPO significantly sustained blood acid-base balance compared with CON, whereas HYPER did not. This suggests that low tonicity ORS with a high SID are more suitable for diarrheic calves.

The effects of differential feeding on ileum development, digestive ability and health status of newborn calves

Pre-weaning is the most important period for the growth and development of calves. Intestinal morphology, microbial community and immunity are initially constructed at this stage, and even have a lifelong impact on calves. Early feeding patterns have a significant impact on gastrointestinal development and microbial communities. This study mainly analyzed the effects of three feeding methods on the gastrointestinal development of calves, and provided a theoretical basis for further improving the feeding mode of calves. it is very important to develop a suitable feeding mode. In this study, we selected nine newborn healthy Holstein bull calves were randomly selected and divided into three groups (n = 3), which were fed with starter + hay + milk (SH group), starter + milk (SF group), total mixed ration + milk (TMR group). After 80 days of feeding Feeding to 80 days of age after, the ileum contents and blood samples were collected, and the differences were compared and analyzed by metagenomic analysis and serum metabolomics analysis. Results show that compared with the other two groups, the intestinal epithelium of the SH group was more complete and the goblet cells developed better. The feeding method of SH group was more conducive to the development of calves, with higher daily gain and no pathological inflammatory reaction. The intestinal microbial community was more conducive to digestion and absorption, and the immunity was stronger. These findings are helpful for us to explore better calf feeding patterns. In the next step, we will set up more biological replicates to study the deep-seated reasons for the differences in the development of pre-weaning calves. At the same time, the new discoveries of neuro microbiology broaden our horizons and are the focus of our future attention.

Prophylactic feeding of neomycin to Holstein calves alters gut microbiota, bile acid metabolism, and expression of genes involved in immunometabolic regulation

The objective of this study was to evaluate the effects of prophylactic neomycin administration on Holstein bull calves' intestinal microbiota, bile acid (BA) metabolism, and transcript abundance of genes related to BA metabolism. A total of 36 calves were blocked by body weight and assigned to either non-medicated milk replacer (CTL), or neomycin for 14 days (ST) or 28 days (LT) in their milk replacer. At the end of the study, calves were euthanized to collect tissue and digesta samples from the gastrointestinal tract, liver, and adipose tissue for analysis of intestinal microbial diversity, bile acid concentration and profile in various body tissues, and gene expression related to bile acid, lipid, carbohydrate metabolism, and inflammation. Calves that received prophylactic administration of neomycin for 28 d (LT) had reduced species richness (chao1 index), and tended to have reduced phylogenetic diversity in the ileum tissue. The relative abundance of Lactobacillus, and Bifidobacterium in ileum and colon digesta were decreased in LT compared with CTL. Concentrations of primary, secondary, and total BA were increased by ST in ileal tissue. In plasma, ST and LT treatments had lower concentrations of secondary BA. Gene expression of the BA receptor FXR was increased in ileum and liver by LT compared to CTL. The expression of FXR and TGR5 in the liver was increased in the ST group compared with CTL, and in adipose tissue, 5 genes related to triglyceride, gluconeogenesis, and immune activation were differentially expressed between CTL and ST. In conclusion, we provide evidence that prophylactic administration of neomycin leads to aberrant changes in BA concentration and profile in different compartments of the enterohepatic system through a process that possibly entails antimicrobial disruption of key bacterial groups, which persists even after cessation of neomycin administration. Additionally, we uncovered an apparent link between dysregulated BA metabolism and changes in lipid metabolism and immune activation in adipose tissue and liver.

Colostrum insulin supplementation to neonatal Holstein bulls affects small intestinal histomorphology, mRNA expression, and enzymatic activity with minor influences on peripheral metabolism

The objectives of this study were to evaluate how varying colostral insulin concentrations influenced small intestinal development and peripheral metabolism in neonatal Holstein bulls. Insulin was supplemented to approximately 5× (70.0 μg/L; n = 16) or 10× (149.7 μg/L; n = 16) the basal colostrum insulin (12.9 μg/L; BI, n = 16) concentration to maintain equivalent macronutrient intake (crude fat: 4.1 ± 0.06%; crude protein: 11.7 ± 0.05%; and lactose: 1.9 ± 0.01%) among treatments. Colostrum was fed at 2, 14, and 26 h postnatal and blood metabolites and insulin concentration were measured at 0, 30, 60, 90, 120, 180, 240, 360, 480, and 600 min postprandial respective to the first and second colostrum meal. At 30 h postnatal, a subset of calves (n = 8/treatment) were killed to excise the gastrointestinal and visceral tissues. Gastrointestinal and visceral gross morphology and dry matter and small intestinal histomorphology, gene expression, and carbohydrase activity were assessed. Insulin supplementation tended to linearly reduce the glucose clearance rate following the first meal, whereas after the second meal, supplementation linearly increased the rate of glucose absorption and nonesterified fatty acid clearance rate, decreased the time to maximum glucose concentrations, and decreased the time to reach minimum nonesterified fatty acid concentrations. Additionally, insulin clearance rate was linearly increased by insulin supplementation following the second colostrum feeding. However, there were no overall differences between treatments in the concentrations of glucose, nonesterified fatty acids, or insulin in plasma or serum. With respect to macroscopic intestinal development, dry rumen tissue mass linearly decreased when insulin was supplemented in colostrum, and supplementation linearly increased duodenal dry tissue density (g dry matter/cm) while tending to increase duodenal dry tissue weight. Increasing the colostrum insulin concentration improved small intestinal histomorphological development in the distal small intestine, as ileal villi height and mucosal-serosal surface area index were increased by supplementing insulin. Lactase enzymatic activity linearly increased in the proximal jejunum while ileal isomaltase activity linearly decreased with insulin supplementation. These data indicate that changes in colostrum insulin concentrations rapidly affect gastrointestinal growth prioritization and carbohydrase activity. The changes in gastrointestinal ontology result in minor changes in postprandial metabolite availability and clearance.

Transcriptome Analysis to Elucidate the Effects of Milk Replacer Feeding Level on Intestinal Function and Development of Early Lambs

Although early feeding strategies influence intestinal development, the effects of milk replacer (MR) feeding level on intestinal structure and functional development and underlying regulatory mechanisms remain unclear. In this study, 14 male Hu lambs were fed MR at 2% or 4% of their average body weight and weaned at 35 days of age. The MR was produced by the Institute of Feed Research of the Chinese Academy of Agricultural Sciences, and it contains 96.91% dry matter, 23.22% protein, and 13.20% fat. Jejunal tissues were assessed by RNA-seq for differences in the gene expression of lambs at 49 days of age; regulatory pathways and mechanisms of the effects of early nutrition on intestinal function and development were analyzed, along with growth performance, feed intake, jejunal histomorphology, and digestive enzyme activities. Increasing MR- feeding levels increased dry matter intake and daily gain before weaning, as well as lactase, amylase, lipase, trypsin, and chymotrypsin activities and intestinal villus length and muscular thickness. Overall, 1179 differentially expressed genes were identified, which were enriched in nutrient metabolism, coagulation cascades, and other pathways. Further, intensive MR feeding affected insulin sensitivity to reduce excessive glucose interception by intestinal tissues to ensure adequate absorbed glucose release into the portal circulation and promoted lipid and protein degradation in intestinal tissues to meet the energy demand of intestinal cells by regulating AHSG, IGFBP1, MGAT2, ITIH, and CYP2E1 expression.

Gastrointestinal structure and function of preweaning dairy calves fed a whole milk powder or a milk replacer high in fat

The composition of milk replacer (MR) for calves greatly differs from that of bovine whole milk, which may affect gastrointestinal development of young calves. In this light, the objective of the current study was to compare gastrointestinal tract structure and function in response to feeding liquid diets having a same macronutrient profile (e.g., fat, lactose, protein) in calves in the first month of life. Eighteen male Holstein calves (46.6 ± 5.12 kg; 1.4 ± 0.50 d of age at arrival; mean ± standard deviation) were housed individually. Upon arrival, calves were blocked based on age and arrival day, and, within a block, calves were randomly assigned to either a whole milk powder (WP; 26% fat, DM basis, n = 9) or a MR high in fat (25% fat, n = 9) fed 3.0 L 3 times daily (9 L total per day) at 135 g/L through teat buckets. On d 21, gut permeability was assessed with indigestible permeability markers [chromium (Cr)-EDTA, lactulose, and d-mannitol]. On d 32 after arrival, calves were slaughtered. The weight of the total forestomach without contents was greater in WP-fed calves. Furthermore, duodenum and ileum weights were similar between treatment groups, but jejunum and total small intestine weights were greater in WP-fed calves. The surface area of the duodenum and ileum did not differ between treatment groups, but the surface area of the proximal jejunum was greater in calves fed WP. Urinary lactulose and Cr-EDTA recoveries were greater in calves fed WP in the first 6 h post marker administration. Tight junction protein gene expression in the proximal jejunum or ileum did not differ between treatments. The free fatty acid and phospholipid fatty acid profiles in the proximal jejunum and ileum differed between treatments and generally reflected the fatty acid profile of each liquid diet. Feeding WP or MR altered gut permeability and fatty acid composition of the gastrointestinal tract and further investigation are needed to understand the biological relevance of the observed differences.

Gastrointestinal permeability and inflammatory status of preweaning dairy calves in response to decreasing the ratio of n-6 to n-3 fatty acid in milk replacer

The ratio of n-6 to n-3 fatty acid (FA) is between 2 and 10 times higher in milk replacer (MR) than in whole milk, which may promote inflammation and compromise the integrity of the intestinal epithelium. To evaluate how decreasing the n-6:n-3 FA ratio of MR affects gastrointestinal (GIT) permeability and inflammatory status, 30 dairy calves (2.8 ± 1.06 d of age; mean ± standard deviation) were randomly assigned to be fed an MR with an n-6:n-3 FA ratio of 40:1 (CON; 29.3% crude fat of DM; n = 15) or 6.5:1 (n-3; 29.1% crude fat of DM; n = 15). Calves were fed 7.0 L/d in 2 meals. Calves were weighed and fecal consistency was analyzed weekly. On d 22, calves were administered Cr-EDTA, lactulose, and d-mannitol to assess GIT permeability. Blood and total urine were sequentially collected for 6 and 24 h, respectively, and analyzed for marker content. Whole blood collected 4 h after the meal was subjected to an ex vivo lipopolysaccharide (LPS) challenge to evaluate cytokine secretion from blood cells. Calves were euthanized on d 25 for collection of intestinal tissue samples. Tissue samples were processed to assess FA composition by gas chromatography, histomorphology by bright-field microscopy, and gene expression of tight junction proteins, lipid metabolism enzymes, and immune molecules by real-time quantitative PCR. Data were analyzed using PROC GLIMMIX in SAS (version 9.4, SAS Institute Inc.). Growth performance and fecal consistency were unaffected. Calves fed MR with a lower ratio of n-6 to n-3 FA had 2-fold higher n-3 FA contents and 2-fold lower ratios of n-6 to n-3 FA in proximal jejunum and ileum tissues. Total urinary recovery (0-24 h relative to marker administration) and plasma concentrations of the markers were unaffected. Expression of TJP1 tended to be higher in proximal jejunum tissue and lower in ileum tissue of n-3 calves. The expression of TLR4 and TNFA tended to be higher and CD14 was higher in ileum tissue of n-3 calves. Plasma concentrations of interleukin-4 were decreased in response to the ex vivo LPS challenge in n-3 calves. Histomorphology and GIT permeability were largely unaffected by treatment. Furthermore, the inclusion of linseed and algae oil may promote inflammation, as suggested by greater concentrations of the acute-phase proteins haptoglobin and serum amyloid A postprandially, demonstrating that fat sources should be evaluated for their suitability for MR formulations. Understanding how MR composition affects dairy calf health may improve nutritional strategies on farm.

Macronutrient profile in milk replacer or a whole milk powder modulates growth performance, feeding behavior, and blood metabolites in ad libitum-fed calves

Milk replacers (MR) for calves usually contain more lactose and less fat than bovine whole milk (WM). There are insufficient data to determine whether these MR formulations are optimal for calves fed at high planes of nutrition. Thus, the effect of 3 MR formulations and a WM powder were evaluated on growth, feeding behavior, and blood metabolites in 96 male Holstein calves fed ad libitum and with 45.5 ± 4.30 kg (mean ± SD) BW at arrival. Calves were blocked based on arrival sequence, and randomly assigned within block to one of the 4 treatments (n = 24 calves/group): a high-fat MR (25.0% fat, dry matter basis; 22.5% protein, 38.6% lactose; 21.3 MJ/kg; HF), a high lactose MR (44.6% lactose, 22.5% protein, 18.0% fat; 19.7 MJ/kg; HL), a high protein MR (26.0% protein, 18.0% fat, 41.5% lactose; 20.0 MJ/kg; HP), and a WM powder (26.0% fat; 24.5% protein, 38.0% lactose; 21.6 MJ/kg; WP). In the first 2 wk after arrival, calves were individually housed and were fed 3.0 L of their respective liquid feed 3 times daily at 135 g/L. They were then moved to group housing and fed ad libitum until d 42 after arrival. Weaning was gradual and took place between d 43 and 70 after arrival; thereafter, calves were fed solids only. Concentrates, chopped straw, and water were available ad libitum throughout the study. Body weight was measured, and blood was collected at arrival and then weekly thereafter from wk 1 to 12. Weight gain and height were greater in HL than WP calves. In the preweaning phase, HL and HP-fed calves consumed more milk than WP, and HL-fed calves consumed more milk than HF calves. In wk 10, starter feed intakes were lower in HF calves than in the other groups. In the preweaning phase, ME intakes were the same for all treatments. This suggests that milk intakes were regulated by the energy density of the milk supplied. The percentage of calves requiring therapeutic interventions related to diarrhea was greater in WP-fed calves (29%) than HF and HL calves (4%), whereas HP (13%) did not differ with other groups. This was coupled with lower blood acid-base, blood gas, and blood sodium in WP than in MR-fed calves. Calves fed HF had greater serum nonesterified fatty acids compared with other groups, and greater serum amyloid A compared with WP and HL calves. Among the serum parameters, insulin-like growth factor-1 and lactate dehydrogenase correlated positively with MR intake and average daily gain. The high lactose and protein intakes in HL and HP calves led to greater insulin-like growth factor-1 concentrations than in WP-fed calves. Although growth differences were limited among MR groups, the metabolic profile largely differed and these differences require further investigation.