Factors affecting water balance and fecal moisture content in suckling calves given dry feed.

Holstein bull calves were used to examine factors affecting water balance and fecal moisture content in suckling calves given dry feed for 2 wk from 1 wk of age. In Experiment 1 (n = 16), the shift of water balance (decreased urine volume, and increased water retention and fecal water excretion) and elevation of fecal moisture content were greatest when calf starter and Sudangrass hay were fed in addition to liquid milk replacer, compared with calves receiving only milk replacer. Intermediate changes occurred when calves were fed milk replacer and calf starter or milk replacer, calf starter, and rice straw. Water retention was correlated positively with digestible DMI and negatively with urine volume. Fecal water excretion was highly correlated with fecal DM excretion. In Experiment 2 (n = 18), water balance and fecal moisture content during wk 2 were affected by free access to calf starter and hay from wk 1. Urine volume of calves fed dry feed and milk replacer was lower than that of calves fed only milk replacer; however, when water was available in addition to dry feed, urine volume was similar to that of calves fed only milk replacer. Fecal water excretion was highly correlated with water retention rather than with fecal DM excretion, suggesting a close relationship to extracellular fluid volume. Ruminal fermentation would be an important factor affecting both water balance and fecal moisture content in suckling calves given dry feed.     

Effects of hydrolyzed spray dried red blood cells in milk replacer on calf intake, body weight gain, and efficiency

An alternative protein ingredient based on spray-dried, hydrolyzed red blood cells was evaluated in calf milk replacers. Two experiments were conducted to determine the value of the ingredient on intake, growth, and feed efficiency in dairy calves. In experiment 1, Holstein bull calves (n = 120) were fed calf milk replacer containing 0, 11, 22, or 43% of crude protein as spray dried hydrolyzed red blood cells. Calves were fed 454 g/d of experimental milk replacer reconstituted to 12% dry matter plus a conventional calf starter for 28 d. Body weight gain, intake of milk replacer and calf starter, feed efficiency, fecal scores, and days scouring were unaffected by source of protein. In experiment 2, Holstein calves (n = 69) at the University of Minnesota, Crookston and Waseca were fed milk replacer containing 0, 22, or 43% of crude protein as spray dried hydrolyzed red blood cells. Calves were fed 454 g/d of experimental milk replacer reconstituted to 12% dry matter plus a conventional calf starter containing 0 or 25% alfalfa meal for 35 d. No calves died during the study. Body weight gain, feed efficiency, intake of calf starter and milk replacer, fecal scores, and days scouring were unaffected by increasing hydrolyzed red blood cells in milk replacer. Similar performance of all calves indicated that spray dried hydrolyzed red blood cells can replace up to 43% of crude protein from whey protein concentrate without detrimental effects on animal performance.     

Effect of conventional and intensified milk replacer feeding programs on performance, vaccination response, and neutrophil mRNA levels of Holstein calves

This study compared conventional and intensified milk replacer feeding regimens on growth, intake, respiratory and fecal scores, vaccination response, and neutrophil mRNA levels. Holstein calves were randomly assigned to a 10-wk study on d 2 of life. Treatments were conventional (CON; n=8) and intensified (INT; n=7) milk replacer feeding programs. Conventional calves were fed a 20.8% crude protein and 21.0% fat milk replacer at 1.25% of birth body weight (BW) from wk 1 to 6 of life and 0.625% of birth BW during wk 7. A 29.3% crude protein and 16.2% fat milk replacer was fed to INT calves at 1.5% of birth BW during wk 1, 2% of current BW from wk 2 to 6, and 1% of current BW during wk 7. All calves were given milk replacer twice daily during wk 1 to 6, once daily during wk 7, and were weaned completely during wk 8. Calf starter intake was measured daily through wk 8. Body weight and withers height were measured weekly. Fecal and respiratory scores were recorded twice daily at feeding. Calves were vaccinated against ovalbumin at the end of wk 1, 3, and 5. Blood samples were collected at the end of wk 1, 3, 5, and 8 for analysis of serum anti-ovalbumin IgG concentration and for isolation of neutrophils. Quantitative PCR was used to measure neutrophil mRNA levels of 7 functionality genes. Treatment did not affect total DMI or anti-ovalbumin IgG response. Intensified milk replacer feeding increased average daily gain, protein intake, fat intake, and feed efficiency compared with the CON feeding program. Compared with CON calves, INT calves had greater fecal scores, indicating looser feces and greater respiratory scores, indicating more respiratory problems. Calves assigned to the INT treatment had increased neutrophil mRNA levels of L-selectin, and at wk 8, neutrophil cytosolic factor 1 was increased and toll-like receptor 4 tended to be increased compared with CON calves. This suggests greater activation of neutrophils in INT calves postweaning, but differences were relatively small and levels of the other 4 genes were unaffected. An INT milk replacer feeding program increased growth, fecal scores, and respiratory scores preweaning, increased mRNA levels of 2 neutrophil genes postweaning, and did not affect vaccination response.     

Feeding acidified or sweet milk replacer to dairy calves

The objective of this study was to compare performance of calves fed acidified milk replacer or regular (sweet) milk replacer twice daily at 10% of BW. Thirty-seven female Holstein calves were fed replacers reconstituted to 12.5% DM for 4 wk, At 28 d, half of the amounts of milk replacer consumed during wk 4 were fed during wk 5 and calves weaned from replacer at d 35 age. A pelleted starter feed was offered for ad libitum access throughout the 42-d trial. Body weight was recorded at birth, d 3 of age, and weekly thereafter. Fecal consistency scores were recorded. Other parameters were measured on d 3 and 42. Average daily gains (d 3 to 42) for calves fed sweet and acidified milk replacers were .33 and .38 kg/d. Starter consumption was similar for both treatments. Calves fed acidified milk replacer (d 3 to 28) had a lower (1.4 vs. 1.6) fecal consistency score than those fed sweet milk replacer (scale of 1 to 4, 1 = normal and 4 = watery). Benefits of feeding acidified milk replacer at 10% of BW per day may be in reducing the incidence of some infectious scours, although further experiments are needed to verify this.     

Influence of starter protein content on growth of dairy calves in an enhanced early nutrition program

Our objectives were to determine the effect of starter crude protein (CP) content on growth of Holstein calves from birth to 10 wk of age in an enhanced early nutrition program, and to compare the enhanced program to a conventional milk replacer program. Calves (64 female, 25 male) were assigned to 3 treatments in a randomized block design: 1) conventional milk replacer (20% CP, 20% fat) plus conventional starter [19.6% CP, dry matter (DM) basis], 2) enhanced milk replacer (28.5% CP, 15% fat) plus conventional starter, and 3) enhanced milk replacer plus high-CP starter (25.5% CP, DM basis). Calves began treatments (n=29, 31, and 29 for treatments 1 to 3) at 3 d of age. Conventional milk replacer (12.5% solids) was fed at 1.25% of birth body weight (BW) as DM daily in 2 feedings from wk 1 to 5 and at 0.625% of birth BW once daily during wk 6. Enhanced milk replacer (15% solids) was fed at 1.5% of BW as DM during wk 1 and 2% of BW as DM during wk 2 to 5, divided into 2 daily feedings. During wk 6, enhanced milk replacer was fed at 1% of BW as DM once daily. Calves were weaned at d 42. Starter was available for ad libitum intake starting on d 3. Starter intake was greater for calves fed conventional milk replacer. For calves fed enhanced milk replacer, starter intake tended to be greater for calves fed enhanced starter. During the weaning period, enhanced starter promoted greater starter DM intake than the conventional starter. Over the 10-wk study, the average daily gain of BW (0.64, 0.74, and 0.80 kg/d) was greater for calves fed enhanced milk replacer with either starter and, for calves fed enhanced milk replacer, tended to be greater for calves fed high-CP starter. Rates of change in withers height, body length, and heart girth were greater for calves fed enhanced milk replacer but did not differ between starter CP concentrations. The postweaning BW for enhanced milk replacer treatments was greater for calves receiving the enhanced starter at wk 8 (73.7, 81.3, and 85.8 kg) and wk 10 (88.0, 94.9, and 99.9 kg). Starter CP content did not affect height, length, or heart girth within enhanced milk replacer treatments. Regression analysis showed that gain of BW during the first week postweaning (wk 7) increased with greater 3-d mean starter intake in the week before weaning. Starter with 25.5% CP (DM basis) provided modest benefits in starter intake (particularly around weaning) and growth for dairy calves in an enhanced early nutrition program compared with a conventional starter (19.6% CP).     

Relationships between protein and energy consumed from milk replacer and starter and calf growth and first-lactation production of Holstein dairy cows

The objective was to determine relationships between protein and energy consumed from milk replacer and starter and calf growth and first-lactation production of Holstein heifer calves. Milk replacer and starter protein intake and metabolizable energy (ME) intake data were collected from 4,534 Holstein heifer calves for growth and 3,627 Holstein cows for production from birth year of 2004 through 2014. Calves from 3 commercial dairy farms were assigned to 45 different calf research trials at the University of Minnesota Southern Research and Outreach Center, Waseca, Minnesota, from 3 to 195 d of life. Calves were moved to heifer growers at 6 mo of age, and calves were returned to their farm of birth a few weeks before calving. Most calves (85%) were fed a 20% crude protein and 20% fat milk replacer at a rate of 0.57 kg/calf daily. Metabolizable energy and protein consumed from milk replacer and starter were calculated for each individual calf for 6 and 8 wk of age. Mixed model analyses were conducted to determine the effect of protein and energy consumed from both milk replacer and starter on calf growth and first-lactation 305-d production of milk, fat, and protein, adjusting for herd, season of birth, year, average daily gain (ADG), and calf trial. Calves with ADG >0.80 kg/d consumed more combined protein and ME than calves with lower ADG. Protein and ME intake from calf starter affected growth more than protein and ME intake from milk replacer because most calves were fed the same fixed amount of milk replacer. Calves born during the fall and winter had greater combined protein and ME intake than calves born during the spring and summer. Milk replacer protein and ME intake did not have a relationship with first-lactation 305-d milk, fat, and protein production. However, starter protein and ME intake during the first 6 and 8 wk of age had a significant positive relationship with first-lactation 305-d milk, fat, and protein production. Consequently, combined protein and combined ME intake had a positive effect on 305-d milk, fat, and protein production. Variance in protein and ME intake was high, suggesting that additional factors affect calf growth during the first 8 wk of life and milk production in first lactation.     

Short communication: Effects of increasing protein and energy in the milk replacer with or without direct-fed microbial supplementation on growth and performance of preweaned Holstein calves

Forty-four Holstein calves were fed a direct-fed microbial (DFM) and 1 of 2 milk replacers to evaluate calf performance and growth. Treatments were (1) a control milk replacer [22:20; 22% crude protein (CP) and 20% fat], (2) an accelerated milk replacer (27:10; 27% CP and 10% fat), (3) the control milk replacer with added DFM (22:20+D), and (4) the accelerated milk replacer with added DFM (27:10+D). Dry matter intake, rectal temperatures, respiration scores and rates, and fecal scores were collected daily. Body weight, hip and withers height, heart girth, blood, and rumen fluid samples were collected weekly. Effects of treatment, sex, week, and their interactions were analyzed. Calves fed an accelerated milk replacer, regardless of DFM supplementation, consumed more CP and metabolizable energy in the milk replacer. No treatment differences were found for starter intake or intake of neutral detergent fiber or acid detergent fiber in the starter. Calves fed the accelerated milk replacer had greater preweaning and weaning body weight compared with calves fed the control milk replacer. Average daily gain was greater during the preweaning period for calves fed the accelerated milk replacer, but the same pattern did not hold true during the postweaning period. Feed efficiency did not differ among treatments. Hip height tended to be and withers height and heart girth were greater at weaning for calves fed the accelerated milk replacer compared with calves fed the control milk replacer. Fecal scores were greatest in calves fed DFM. Overall acetate, propionate, butyrate, and n-valerate concentrations were lower in calves fed the accelerated milk replacer, but DFM did not have an effect. Rumen pH was not different. Blood metabolites were unaffected by DFM supplementation, but calves fed the accelerated milk replacer had increased partial pressure of CO₂, bicarbonate, and total bicarbonate in the blood. Direct-fed microbial supplementation did not appear to benefit the calf in this trial     

Response of young dairy calves with lasalocid delivery varied in feed sources.

Growth, age at weaning, fecal scores, and blood metabolites of young dairy calves were measured to determine the most effective method of lasalocid administration. Forty Holstein bull calves were blocked by date of birth and assigned randomly to one of four treatment groups: no lasalocid; lasalocid in starter; lasalocid in prestarter and starter; or lasalocid in milk, prestarter, and starter for a 12-wk period. Calves were fed milk twice daily until they consumed 227 g/d of prestarter, at which time the p.m. milk feeding was discontinued, and starter was offered for ad libitum intake as a mixture with the 227 g/d of prestarter. When total dry feed consumption reached 1.3% of birth weight, the calf was weaned. When the calf was 5 wk of age, the prestarter was discontinued. Daily gain tended to be greatest during the first 6 wk for the calves receiving lasalocid in milk, prestarter, and starter. These calves also were weaned with less variation in days to weaning. By wk 8 through 12, there were no differences in gain among the treatment groups.     

Growth and health of Holstein calves fed milk replacers supplemented with antibiotics or Enteroguard

Forty-five Holstein calves were fed milk replacers containing either antibiotics [MRA (oxytetracycline at 138 mg/kg and neomycin at 276 mg/kg), n = 22)] or Enteroguard [MRE, a blend of fructooligosaccharides, allicin, and gut-active microbes at (129 mg/kg, n = 23)] from birth to 5 wk of age to compare effects on average daily gain and on incidence of scours. Performance was evaluated by measuring weight gain, feed efficiency, and fecal scores. The overall body weight gains and severity of scours were not different between treatments, nor were there differences in starter intake or mean body weight gain. During wk 2, the average gain of calves fed MRA was less than that of calves fed MRE (0.07 vs. 0.09 kg/d, P = 0.09), and greater during wk 5 (0.62 vs. 0.51 kg/d, P < 0.01); however, total gain for calves fed MRE was not different from calves fed MRA. Likewise, average feed efficiencies (gain/dry matter intake) were not different. Severity of scours, as measured by fecal scores, and concentrations of serum proteins, an indirect measure of immunoglobulins, were similar for calves fed MRA and MRE. The results suggest that antibiotics in milk replacers can be replaced with compounds such as fructooligosaccharides, probiotics, and allicin to obtain similar calf performance.     

Relationships between early-life growth,intake, and birth season with first-lactation performance of Holstein dairy cows

The objective was to determine the relationships between early-life parameters [including average daily gain (ADG), body weight (BW), milk replacer intake, starter intake, and birth season] and the first-lactation performance of Holstein cows. We collected data from birth years 2004 to 2012 for 2,880 Holstein animals. Calves were received from 3 commercial dairy farms and enrolled in 37 different calf research trials at the University of Minnesota Southern Research and Outreach Center from 3 to 195 d. Upon trial completion, calves were returned to their respective farms. Milk replacer options included varying protein levels and amounts fed, but in the majority of studies, calves were fed a milk replacer containing 20% crude protein and 20% fat at 0.57 kg/calf daily. Most calves (93%) were weaned at 6 wk. Milk replacer dry matter intake, starter intake, ADG, and BW at 6 wk were 21.5 ± 2.2 kg, 17.3 ± 7.3 kg, 0.53 ± 0.13 kg/d, and 62.4 ± 6.8 kg, respectively. Average age at first calving and first-lactation 305-d milk yield were 715 ± 46.5 d and 10,959 ± 1,527 kg, respectively. We conducted separate mixed-model analyses using the REML model-fitting protocol of JMP (SAS Institute Inc., Cary, NC) to determine the effect of early-life BW or ADG, milk replacer and starter intake, and birth season on first-lactation 305-d milk, fat, and true protein yield. Greater BW and ADG at 6 wk resulted in increased first-lactation milk and milk component yields. Intake of calf starter 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. Calves born in the fall and winter had greater starter intake, BW, and ADG at 8 wk. However, calves born in the summer had a higher 305-d milk yield during their first lactation than those born in the fall and winter. Improvements were modest, and variation was high, suggesting that additional factors not accounted for in these analyses affected first-lactation performance.     

Performance and fecal flora of calves fed a Bacillus subtilis concentrate

Eighty-four Holstein calves were assigned at 2 d of age to one of three treatments: 1) control with no additives; 2) 10 g of a mixed microbial concentrate containing Lactobacillus acidophilus, Lactobacillus lactis, and Bacillus subtilis; or 3) 10 g of a B. subtilis concentrate. The microbial concentrates were mixed with milk replacer during the a.m. feeding. The milk replacer was offered twice daily at 5% BW per feeding; the reconstituted replacer contained 12.5% DM. Volume of replacer fed was based on initial weight of calf and held constant until weaning. Water and starter ration were offered for ad libitum intake throughout the trial. Calves were weaned abruptly at 30 d of age and received only water and starter from d 31 to 44. General health and performance of all calves were good. Although differences in weight gain and feed efficiency were not significant, the B. subtilis concentrate tended to have a positive effect on feed efficiency during wk 1 to 4 and on immediate postweaning gain. A higher fecal bacilli count at 6 wk in calves fed the microbial concentrates may be related to their tendency for improved gain during d 31 to 44, the immediate postweaning period.     

Effects of spray-dried animal plasma in milk replacers or additives containing serum and oligosaccharides on growth and health of calves

The effects of spray-dried animal plasma in milk replacer without or with the addition of additives containing fructooligosaccharides and spray-dried serum on health, growth, and intake of Holstein calves was measured in two 56-d experiments. In experiment 1, 120 calves were fed milk replacer containing 0 or 20% of crude protein as spray-dried bovine plasma for 42 d and 30 to 60 g/d of additives containing whey protein concentrate or bovine serum for the first 15 d. Commercial calf starter was available from d 29, and water was available at all times. In experiment 2, 120 calves were fed milk replacer containing 0 or 16% of crude protein as spray-dried bovine plasma with 0 or 30 to 60 g/d of additive containing bovine serum for the first 15 d. Additive containing bovine serum also contained fructooligosaccharides, whey, and vitamin/mineral premix. In experiment 1, calves fed additive containing bovine serum tended to have fewer days with diarrhea, lower use of electrolytes, and improved BW gain from d 29 to 56. The addition of spray-dried bovine plasma to milk replacer did not influence any parameter measured. In experiment 2, calves fed additive containing bovine serum or milk replacer containing spray-dried bovine plasma had lower mortality (4.4 vs. 20%) and tended to have improved fecal scores and fewer days with scours. Antibiotic use was lower when calves were fed the additive. Indices of enteric health (incidence of scours and treatment with antibiotics and electrolytes) were improved when plasma was added to milk replacer throughout the milk feeding period or as an additive during the first 15 d of the milk feeding period, when calves were most susceptible to enteric pathogens. The addition of spray-dried animal plasma to milk replacer or the addition of additive containing spray-dried bovine serum and oligosaccharides may be a useful adjunct to animal management during periods of stress.     

Growth, health, and blood glucose concentrations of calves fed high-glucose or high-fat milk replacers

The influence of age, carbohydrate-fat ratios of milk replacers, and development of ruminal function on growth, health, and blood glucose concentrations were evaluated in calves. Colostrum-fed, 3-day-old Holstein bull calves were fed to 12 wk on one of three dietary treatments: 1) a high carbohydrate, low fat (60.5% glucose, 9.5% lactose, and 3% lard) milk replacer; 2) a low carbohydrate, high fat (23% glucose, 12.5% lactose, and 30% lard) milk replacer; and 3) weaning at 6 wk of age from high-fat replacer to a standard calf starter. The high fat milk replacer was superior to low fat milk replacer for total weight gains and efficiency of feed conversion. Rates of weight gain of starter calves were similar to those of calves fed low fat. Calves fed the diet with low fat had a high incidence of diarrhea, an occasional outbreak of a yeast-related ethanol intoxication syndrome, and high concentrations of glucose in urine. Irrespective of milk replacer composition or development of ruminal function, plasma and whole blood glucose concentrations declined rapidly in the first 6 wk. Corpuscular glucose declined steadily with age in all calves. This age-related decrease of blood glucose concentration of calves seems to be a constitutive phenomenon.     

Effects of amount of colostrum replacer,amount of milk replacer,and housing cleanliness on health,growth, and intake of Holstein calves to 8 weeks of age

Newborn Holstein bull calves (n = 96) were assigned randomly at birth to receive 150 g (C150) or 450 g (C450) of IgG in the first 24 h of life from a lacteal-based colostrum replacer in 2 trials. Mass of product fed was 500 and 1,500 g, respectively. Replacer was reconstituted with warm water and administered by esophageal feeder at approximately 1, 6, and 12 h of age. Thereafter, calves were fed 2 L of whole milk twice daily at approximately 0700 and 1700 h until transported to the experimental facility at 2 to 3 d of age. Calves fed C450 had greater serum total protein and IgG concentrations at 2 to 3 d of age. Failure of passive transfer of immunity (serum IgG <10 g/L) was detected in 100 and 11% of calves fed C150 and C450, respectively. Calves (n = 48) in trial 1 were assigned randomly within colostrum group to receive 0.68 kg/d of milk replacer (MR) for 42 d, and then 0.34 kg/d for 7 d (moderate MR, MMR) or 1 kg/d of MR for 5 d, 1.36 kg/d for 37 d, and 0.68 kg/d for 7 d (high MR, HMR). Starter and water were available for ad libitum consumption. Calves fed HMR had greater average daily gain, higher average fecal scores, more days with abnormal fecal scores, and more medical days than calves fed MMR. Calves fed HMR also had lower starter intake and tended to have lower gain-to-feed ratio than calves fed MMR. Calves fed C450 and MMR began eating calf starter earlier and ate more starter than other groups from 3 wk. In trial 2, calves (n = 48) were assigned randomly within colostrum group to housing in nursery pens bedded with clean, dry straw (clean bedding) or soiled straw used in previous studies (dirty bedding). Milk replacer was fed at 0.68 kg/d for 39 d, and then 0.34 kg/d for 3 d along with free-choice texturized starter and water. Calves fed C450 had fewer days with abnormal fecal scores and days with medical treatments compared with calves fed C150. Calves housed in dirty bedding tended to grow more slowly and have lower gain-to-feed ratio than calves housed with clean bedding. Temporal changes in serum IgG and total protein varied by treatment. Serum IgG in calves fed C150 varied little from 0 to 4 wk and increased thereafter, whereas IgG in calves fed C450 declined to 4 wk (estimated half-life = 23.9 d) and increased thereafter. Differences in serum IgG concentrations caused by feeding different amounts of colostrum replacer did not markedly affect growth or intake when calves were fed different amounts of milk replacer or when they were housed with clean or dirty bedding.     

Effects of colostrum and milk replacer feeding rates on intake,growth, and digestibility in calves

Newborn Holstein male calves (n = 50) born on a single dairy farm were assigned randomly at birth to receive 3 feedings of 1.8 L of pooled maternal colostrum (MC) at 1, 6, and 12 h of age or 1 feeding of 500 g of a colostrum replacer reconstituted to 1.8 L at 1 h of age, followed by 2 feedings of 227 g of a commercial milk replacer (MR) reconstituted to 1.8 L at 6 and 12 h of age (CR). All feedings were administered by esophageal feeder. At 2 to 3 d of age, calves were transported to the experimental facility and assigned within colostrum group to receive 0.66 kg/d dry matter (DM) of MR to 39 d, and then 0.33 kg/d to 42 d (MRM) or 0.77 kg/d of MR DM to d 13, 1.03 kg/d for 22 d, and 0.51 kg/d for 7 d (MRH). The MR contained 25.8% crude protein and 17.6% crude fat (DM basis) and was based on whey proteins and lard as the primary fat source. Calf starter (21.7% crude protein, 15.7% neutral detergent fiber, 37.4% starch, DM basis) and water were available for ad libitum consumption throughout the 56-d study. Serum IgG and total protein were measured at 2 to 3 d of age. Intakes of MR and calf starter were monitored daily. Calf health and fecal scores were also monitored daily. Body weight was measured weekly, and hip width and body condition score were monitored every 2 wk. Digestion of DM, organic matter, crude protein, and ether extract were determined at 1 and 3 wk from 5 calves randomly selected within treatment and using chromic oxide as a digestibility marker added to the MR. Calves fed CR had lower serum IgG and total protein than calves fed MC. Also, calves fed CR grew more slowly, consumed less calf starter, and were less efficient to 56 d than calves fed MC. The number of days calves were treated with veterinary medications was higher when calves were fed CR. Calves fed MC-MRH gained more BW than other calves from 3 to 8 wk of age. Calves fed CR-MRH consumed less calf starter than other calves during wk 7 and 8. Digestion of nutrients at 1 and 3 wk of the study was unaffected by type of colostrum or level of MR fed and did not change from 1 to 3 wk. Over the first 2 mo of life, the calves fed MRH consumed less calf starter than calves fed MRM, but average daily gain or hip width change did not differ. One feeding of CR followed by 2 feedings of MR in the first 24 h likely reduced absorption of IgG from CR and contributed to differences in health and growth. Differences in animal performance observed in this study were unrelated to MR digestibility.     

Effect of extra energy as fat or milk replacer solids in diets of young dairy calves on growth during cold weather.

The effects of feeding two levels of supplemental fat and extra milk replacer solids on Holstein calves housed in hutches during the winter were investigated. Fifty calves (10 per treatment) were assigned to the following dietary treatments: 1) milk replacer (control) reconstituted to 12.5% DM fed at 10% of BW (adjusted weekly), 2) same as treatment 1 plus 113 g/d of supplemental fat, 3) milk replacer reconstituted to 15% DM and fed at 10% of BW (adjusted weekly), 4) same as treatment 1 plus 226 g/d of supplemental fat, and 5) milk replacer reconstituted to 15% DM fed at 14% of BW (adjusted weekly). Half the amount of milk replacer consumed during wk 4 was fed during wk 5, and calves were weaned to dry feed at 35 d of age. A pelleted starter was offered for ad libitum intake throughout the 42-d trial. Gains in BW were greater for calves fed 226 than 113 or 0 g/d of supplemental fat (d 3 to 28). Calves fed milk replacer reconstituted to 15% DM at 14% of BW had greater BW gains during d 3 to 28 than control. Starter consumption was similar between groups receiving 113 and 0 g/d of fat supplement but lower in the group fed 226 g/d. Extra milk replacer solids in diets increased fecal scores to levels greater than those of calves in other groups. The benefit of fat supplementation of milk replacers was manifested as increased BW gain during the 1st mo of life.     

Performance of Calves Fed Milk Replacer Once Daily at Various Fluid Intakes and Dry Matter Concentrations

Ninety-six Holstein calves were fed 1 of 12 liquid diets once daily under two feeding options. Diets consisted of milk replacer (22% crude protein, 10% fat) fed at fluid intakes of 6, 8, and 10% body weight and dry matter concentrations of 10, 13, 16, and 19%. Feeding options consisted of calculating fluid intake and dry matter concentration based on initial weight and holding this constant through weaning or adjusting weekly according to change in body weight. Water and a complete calf starter (minimum 15% crude protein) were available ad libitum. Calves were weaned abruptly at 4 wk of age and observed until 6 wk of age for immediate postweaning performance. Fluid intake and dry matter concentration had a positive effect on weight gain during wk 0 to 4. However, during the immediate postweaning period, gain decreased in calves previously fed replacer at the higher intake. Overall gain (wk 0 to 6) was not affected by fluid intake or dry matter concentration. Starter intake decreased with increasing fluid intake or dry matter concentration during wk 4 and wk 0 to 4. Total intakes of dry matter were not affected by treatment. Incidence of scours increased linearly with dry matter concentration, and both fluid intake and dry matter concentration had a positive linear effect on fecal score and duration of scours. Feeding option had no effect on any measures. Calves fed replacer containing between 10 and 13% dry matter and offered at 8% body weight had fewer intestinal disturbances during the replacer feeding period and obtained recommended gains over the entire 6 wk.     

Effect of supplementation with algae β-glucans on performance,health, and blood metabolites of Holstein dairy calves

Studies have shown that β-glucans extracted from the cell wall of cereals, algae, and yeasts have been associated with improved immune function. However, it is unknown whether algae β-glucan supplementation affects the performance, blood metabolites, or cell counts of immune cells in dairy calves. The objective of this randomized clinical trial was to evaluate whether supplementation of β-glucans to milk replacer in dairy calves fed 6 L/d improved growth performance and fecal status and altered the blood metabolite profile. In this trial, we enrolled Holstein calves (n = 34) at birth (body weight 36.38 ± 1.33 kg; mean ± standard deviation) to receive, from 1 d of age, either 2 g/d algae β-glucans mixed into 6 L/d of milk replacer (22.4% crude protein and 16.2% fat) or an unsupplemented milk replacer (control). The calves were blocked in pairs according to birth weight, sex, and date of birth (up to 5 d difference). Calves were housed individually, and calf starter (24.7% crude protein and 13.9% neutral detergent fiber) was offered ad libitum based on orts of the previous day until 56 d of age (end of the trial). Body weight was measured weekly, and health checks and daily fecal consistency were evaluated daily in every calf by the same observer. Calves with 2 consecutive days of loose feces that sifted through bedding were considered diarrhea positive. We used a linear mixed effects model to evaluate the effects of β-glucan supplementation fed during the preweaning period on performance (average daily gain), final weight, feed efficiency (FE), white blood cell count, and selected blood metabolites, repeated by time. A generalized linear mixed effects model was also run to evaluate the likelihood of a diarrhea bout in the first 28 d of life, controlling for the calf as the subject with a logistic distribution. We included age, serum total protein at 48 h, and birth weight as covariates. At 56 d, β-glucan-supplemented calves weighed more than control calves (56.3 vs. 51.5 kg). Treatment had no effect on total starter intake, but there was a treatment by age interaction for FE, with greater FE for β-glucan-supplemented calves in wk 3 and 5 of age. There was only a tendency for average daily gain to be greater in supplemented calves than in control calves for the duration of the study. Furthermore, control calves had 14.66 [95% confidence interval (95% CI): 9.87–21.77] times greater odds of having a diarrheal bout than β-glucan-supplemented calves. Control calves had 12.70 (95% CI: 8.82–18.28) times greater odds of having an additional day with an abnormal fecal score compared with β-glucan-supplemented calves, suggesting that supplementation ameliorated diarrhea severity. We found no association of treatment with concentrations of serum total protein, albumin, creatinine, or glucose during the preweaning period. Our findings suggest that dietary supplementation of 2 g/d of algae β-glucans to milk replacer improved fecal status and may affect growth, as evidenced by a higher weaning weight, compared with control calves. Future studies should explore the effect of algae β-glucans on lower-gut physiology and digestibility in dairy calves.     

Feeding Acidified Milk Replacer Ad Libitum to Calves Housed in Group Versus Individual Pens

The purpose of this study was to evaluate group versus individual housing with a cold ad libitum feeding system for calves. Twelve Holstein calves were assigned to group or individual housing at birth. The experiment had two replications, each consisting of one group of 3 calves and 3 individually housed calves. All calves were fed cold acidified milk replacer ad libitum plus calf starter and water. Behavior was studied for one 48-h period during wk 1, 3, and 6. Four male calves were slaughtered at wk 6 for determination of carcass composition. Milk replacer and water intakes in the preweaning period (wk 1 to 5) tended to be higher for group-fed calves. Calf starter intake was not different. Group-housed calves had a higher BW and a slightly higher (although not statistically significant) average daily gain than calves fed in individual pens. Packed cell volume was lower for group calves due to their higher liquid intake, but plasma glucose and urea N concentrations were similar. Individually housed calves spent more time using the nipple and group-fed calves spent more time drinking water. Amount of time eating starter did not differ between treatments but differed with age. Carcass composition was not different between calves housed individually or in groups.Because individually housed calves spent more time using the nipple, but consumed less milk replacer, they may have been exhibiting a form of purposeless behavior. Higher milk replacer intake by group-fed calves did not result in greater carcass fat content at 6 wk of age.     

Influence of Saccharomyces cerevisiae fermentation products,SmartCare in milk replacer and Original XPC in calf starter,on the performance and health of preweaned Holstein calves challenged with Salmonella enterica serotype Typhimurium

This study was designed to investigate the effects of supplementing SmartCare (SC; Diamond V, Cedar Rapids, IA) in milk replacer and Original XPC (XPC; Diamond V) in calf starter on performance and health of preweaned calves following an oral challenge with Salmonella enterica. The study was performed in two 35-d periods with 30 Holstein bull calves (2 ± 1 d of age) per period. In each period, calves were blocked by location in the barn and randomly assigned to treatments that included control, base milk replacer and calf starter with no added Saccharomyces cerevisiae fermentation products; SC, milk replacer with 1 g of SC/calf per day and base calf starter; and SC+XPC, milk replacer with 1 g of SC/calf per day and calf starter with 0.5% XPC on a dry matter basis. Calves were fed 350 g of milk replacer solids at 14% dry matter twice daily at 0700 and 1700 h. Calf starter and water were offered ad libitum and intakes were recorded daily. Calves were challenged with 108 cfu of sulfamethazine-resistant Salmonella enterica serotype Typhimurium orally on d 14 of the study. Fecal Salmonella shedding was determined on d 14 to 21 (daily), 24, 28, and 35 using selective media. Blood samples were collected on d 0, 7, 14, 16, 18, 21, 24, 28, and 35 and analyzed for hematology; plasma were analyzed for haptoglobin concentrations. All data were reported as CON, SC, and SC+XPC, respectively. Calf starter intake was increased from d 22 to 35 among SC+XPC calves and from d 29 to 35 among SC calves. The SC+XPC calves had a lower neutrophil-to-lymphocyte ratio (0.81, 0.83, and 0.69 ± 0.051) throughout the study. The SC+XPC calves also had lower hematocrits (35.1, 35.3, and 33.4 ± 0.54%) and hemoglobin concentrations (10.8, 10.6, and 10.1 ± 0.16 mg/dL) throughout the study. We found a tendency for calves fed SC and SC+XPC to have more solid fecal scores during the week after the challenge. We observed no treatment or treatment × time differences on plasma haptoglobin concentrations (63, 48, and 60 ± 0.5 μg/mL). No treatment differences were observed in the fecal shedding of the Salmonella; however, we noted a tendency for a treatment difference in the percentage of calves positive for Salmonella present in the ileal tissue at d 21 after the challenge (25, 50, and 60%). Supplementing preweaned Holstein calves with both SC in milk replacer and XPC in calf starter improved starter intake and improved fecal consistency immediately after a mild Salmonella enterica challenge, but more data are needed to further understand how these yeast fermentation products influence the immune responses to Salmonella enterica.