Calves Fed Milk Replacer Research Articles

Het geven van vaste voeding aan witvleeskalveren vermindert de uitscheiding van clostridia in de mest

Clostridium perfringens geassocieerde enterotoxemie is een belangrijke oorzaak van sterfte bij kalveren in intensieve opfoksystemen. Het doel van deze studie was om het effect van vaste voeding te beoordelen op de uitscheiding van C. perfringens in de mest bij witvleeskalveren. Twee verschillende testdiëten werden at random toegewezen aan tien holsteinfriesian-witvleeskalveren. De kalveren in groep 1 werden uitsluitend gevoed met melkpoeder, terwijl kalveren in groep 2 zowel melkpoeder als een maximum van 300g vaste voeding per voederbeurt kregen. De vaste voeding bestond uit 30% gerst, 30% mais, 30% tarwe en 10% gehakseld stro. Vervolgens werd het aantal clostridia in de mest bepaald. Kalveren die zowel melkpoeder als vaste voeding kregen, scheidden significant minder clostridia uit in de mest dan kalveren die uitsluitend met melkpoeder werden gevoed. Er moet nog verder onderzocht worden of het verschaffen van vaste voeding aan witvleeskalveren een preventief effect heeft op enterotoxemie.

Pre- and postweaning performance and health of dairy calves fed milk replacers with differing protein sources

ABSTRACT Three studies were conducted to evaluate the effect of partially replacing milk replacer (MR) protein with alternative sources on calf performance and health. Sources evaluated included wheat gluten (WG), soy protein concentrate (SPC), spray dried animal plasma (PL), and plant peptide powder (PP). The control treatment (CON) across all studies was 100% milk protein MR. In study 1, WG and SPC (replacing up to 50% of MR milk protein) decreased (P 0.05) across treatments. Preweaning and overall calf starter intake were reduced (P 0.05). In study 3, there were no differences (P > 0.05) in performance or health between CON calves or those fed MR with PL or PP. Across treatments, calves gained 0.78 kg of BW/d, grew 11.19 cm in hip height, and consumed 51.66 kg of calf starter DM d 1 to 56. In summary, studies 1 and 2 indicate WG and SPC used in these studies can be fed in combination with PL to minimize calf performance effects. Study 3 suggests PL and PP used in these studies can successfully replace up to 25% of milk protein in calf MR.

Nitrogen utilization, preweaning nutrient digestibility, and growth effects of Holstein dairy calves fed 2 amounts of a moderately high protein or conventional milk replacer

Studies have shown that calves fed milk replacers (MR) with crude protein (CP) concentrations greater than 20%, as typically found in conventional MR, have higher dry matter intakes (DMI) and greater average daily gains (ADG) but consume less starter, which can lead to stress during weaning and reduced rumen development. The greater amount of CP being fed to preweaned calves may alter their nitrogen (N) balance, and excess N may be excreted in the urine. The objective of this study was to determine N utilization in preweaned calves fed diets varying in the amount of CP and MR fed. This study used 24 newborn dairy heifer calves blocked by birth and randomly assigned to 1 of 3 treatments: (1) 446g dry matter (DM) of a conventional MR (CON; 20% CP, 20% fat), (2) 669g DM of a moderately high protein MR (moderate; MOD; 26% CP, 18% fat), or (3) 892g DM of a moderately high protein MR (aggressive; AGG; 26% CP, 18% fat). All calves had ad libitum access to starter and water. Both MR and starter were medicated with decoquinate. During weaning (d 43–49), the morning MR feeding ceased. On d 50, all MR feedings ended; however, starter and water intakes were continuously recorded until d 56. At 5wk of age, urine was collected using urinary catheters for 3d and chromium oxide was administered by bolus at 2g/d for 7d to estimate N efficiency. Calves fed MOD and AGG had similar starter intakes, feed efficiencies, and ADG, with the combined treatments having reduced starter intakes (258 vs. 537g/d), greater ADG (674 vs. 422g/d), and improved feed efficiency (0.57 vs. 0.45 gain:feed) compared with CON calves preweaning. However, DMI and water intake were similar across all treatments. Results from the N utilization phase showed that MOD and AGG treatments had similar but lower N efficiency compared with CON calves (45.5 vs. 52.7%). This could be due to MOD- and AGG-fed calves having greater urine volume and thereby, greater combined urine N output compared with CON calves (17.6 vs. 12.1 g/d). In summary, feeding >0.66kg (DM) from a 26% CP MR increased ADG and improved feed efficiency during the preweaning period but reduced starter intake and lowered N efficiency.

Vitamin D status of dairy cattle: Outcomes of current practices in the dairy industry.

The need for vitamin D supplementation of dairy cattle has been known for the better part of the last century and is well appreciated by dairy producers and nutritionists. Whether current recommendations and practices for supplemental vitamin D are meeting the needs of dairy cattle, however, is not well known. The vitamin D status of animals is reliably indicated by the concentration of the 25-hydroxyvitamin D [25(OH)D] metabolite in serum or plasma, with a concentration of 30ng/mL proposed as a lower threshold for sufficiency. The objective of this study was to determine the typical serum 25(OH)D concentrations of dairy cattle across various dairy operations. The serum 25(OH)D concentration of 702 samples collected from cows across various stages of lactation, housing systems, and locations in the United States was 68±22ng/mL (mean ± standard deviation), with the majority of samples between 40 and 100ng/mL. Most of the 12 herds surveyed supplemented cows with 30,000 to 50,000 IU of vitamin D3/d, and average serum 25(OH)D of cows at 100 to 300 DIM in each of those herds was near or above 70ng/mL regardless of season or housing. In contrast, average serum 25(OH)D of a herd supplementing with 20,000 IU/d was 42±15ng/mL, with 22% below 30ng/mL. Cows in early lactation (0 to 30d in milk) also had lower serum 25(OH)D than did mid- to late-lactation cows (57±17 vs. 71±20ng/mL, respectively). Serum 25(OH)D of yearling heifers receiving 11,000 to 12,000 IU of vitamin D3/d was near that of cows at 76±15ng/mL. Serum 25(OH)D concentrations of calves, on the other hand, was 15±11ng/mL at birth and remained near or below 15ng/mL through 1mo of age if they were fed pasteurized waste milk with little to no summer sun exposure. In contrast, serum 25(OH)D of calves fed milk replacer containing 6,600 and 11,000 IU of vitamin D2/kg of dry matter were 59±8 and 98±33ng/mL, respectively, at 1mo of age. Experimental data from calves similarly indicated that serum 25(OH)D achieved at approximately 1mo of age would increase 6 to 7ng/mL for every 1,000 IU of vitamin D3/kg of dry matter of milk replacer. In conclusion, vitamin D status of dairy cattle supplemented with vitamin D3 according to typical practices, about 1.5 to 2.5 times the National Research Council recommendation, is sufficient as defined by serum 25(OH)D concentrations. Newborn calves and calves fed milk without supplemental vitamin D3, however, are prone to deficiency.

0774 The effect of weaning over a fourteen-day versus a twenty-one-day period on the performance of calves fed milk replacer on a controlled ad libitum curve through an automatic feeder

0774 The effect of weaning over a fourteen-day versus a twenty-one-day period on the performance of calves fed milk replacer on a controlled ad libitum curve through an automatic feeder

0773 The effect of phase feeding on feed cost, growth, and performance of calves fed milk replacer

Ninety-six 3- to 10-d-old Holstein bull calves with an average initial BW of 44.1 kg (SD 1.67) were shipped from Wisconsin to the Land O'Lakes Research Facility in northwest Iowa. The objective of this study was to evaluate the use of phase feeding with a milk replacer (MR) containing only milk protein in the first phase and a MR using hydrolyzed soy protein modified (HSPM) in the second phase of calf rearing. Calves were randomly assigned according to BW and blood γ globulin to one of four MR diets offered in a 15% solution: 1) 27% CP containing only milk protein, 10% fat (control); 2) phase feeding, 28% CP, 20% fat in Phase 1 and 22% CP, 15% fat with HSPM in Phase 2; 3) phase feeding, 28% CP, 20% fat in Phase 1 and 25% CP, 15% fat with HSPM in Phase 2; and 4) phase feeding, 28% CP, 20% fat in Phase 1 and 28% CP, 15% fat with HSPM in Phase 2. Calves were fed to provide 816 g DM/d during Days 1 to 6 and 1,135 g DM/d during Days 7 to 41, in 2 feedings at 0600 and 1515 h. Calves were offered 567.5 g in one feeding at 0600 h during the last week. Calf starter (22% CP, as-fed basis) was offered ad libitum throughout this 48-d trial. Data were analyzed by Mixed procedures of SAS. Total weight gain, MR consumption, feed:gain ratio, and starter intake did not differ (P > 0.05) among treatments. Total feed costs over the 7-wk trial were significantly lower (P < 0.05) for the three phase-feeding treatments. Calves on the three phase-fed diets performed equally to calves on the control-fed diets and the feed costs were significantly reduced, making this a viable option where applicable.

Effects of dam parity and pre-weaning average daily gain of Holstein calves on future milk production.

This research communication describes relationships between pre-weaning average daily gain (ADG) and dam parity with future productivity of dairy calves. Higher ADG before weaning has been shown to be related to greater milk production in the first lactation of Holstein calves fed milk replacer. However, data is limited on the relationship between pre-weaning ADG and first lactation performance of Holstein calves fed whole milk. Data of three hundred and thirty-two Holstein calves from 35 primiparous and 297 multiparous cows was investigated to evaluate the relationship between the dam parity and pre-weaning ADG with the first lactation performance. Results indicated that birth (P < 0·01), and weaning body weight (P < 0·001) were greater in calves born from multiparous cows. Neither 305 d milk production nor pre-weaning ADG differed significantly between calves born to primiparous or multiparous cows, although milk yield tended to be higher in the former and ADG higher in the latter. Correlations between 305 d milk yield and pre-weaning ADG, dam parity and birth body weight were low and non-significant, although there was a tendency for a positive correlation between ADG and milk yield.

Evaluation of nutrition models to estimate performance of young dairy calves: a meta-analytical study under tropical conditions

Mathematical models are important tools to estimate nutritional requirements and animal growth. Very few calf models generated from other countries with different feeding programs, environment and production systems have been evaluated. The objective of this paper is to evaluate two calf models: (i) the National Research Council (NRC) in 2001 and (ii) the updates published by Van Amburgh and Drackley in 2005 and inputted into Agricultural Modeling and Training Systems (AMTS, version 3.5.8). Data from 16 previous studies involving 51 diets for dairy calves under tropical conditions (n=485 calves, initial BW 37.5±4.35 kg and weaning weight of 62.0±10.16 kg) were used. The calves were fed with whole milk, milk replacer or fermented colostrum, plus starter (20.9±1.78% of CP). The accuracy of the average daily gain (ADG) prediction was evaluated by mean bias, mean square prediction error (MSPE), concordance correlation coefficient, bias correction factor (Cb), and regression between the observed and predicted values. The ADG observed from birth to weaning was 0.452±0.121 kg/day. Calves fed with whole milk had greater ADG compared with calves fed milk replacer (0.477 v. 0.379 kg/day) during the milk-feeding period. When all data were pooled (n=51 diets), predictions had a mean bias of −0.019 and 0.068 kg/day for energy-allowable gain using NRC and AMTS models, respectively. The regression equation between observed and predicted values obtained from energy of diets showed an intercept different from zero (P<0.0001) and slope that differed from unity (P<0.0001). In a second evaluation, when calves were fed only milk replacer, the energy-allowable gain from AMTS showed the lowest mean bias (0.008 kg/day) and 82.1% of the MSPE value originated from random errors. The lowest MSPE, the higher Cb value and no significant slope bias (P>0.05) indicate that the AMTS growth model resulted in accurate predictions for calves fed with milk replacer. However, within these latter two approaches, the goodness of fit (R2) was low, representing low precision. The weight gain estimated by the energy available from the diet was overestimated by 19 g/day when calculated by the NRC and underestimated by 68 g/day when calculated by AMTS. The reasons for this discrepancy need to be understood, for only then new models could be developed and parameterized to estimate animal performance in tropical conditions more accurately and precisely.

Delayed weaning of Holstein bull calves fed an elevated plane of nutrition impacts feed intake, growth and potential markers of gastrointestinal development

Feeding calves an elevated plane of nutrition pre-weaning improves growth. However, some controversy remains about the optimal time of weaning required to minimize the decline in growth commonly associated to milk withdrawal. This experiment aimed to determine the influence of weaning age on performance of calves fed milk replacer on an elevated plane of nutrition (8L d−1, 150gL−1, 1.2kg calf−1 d−1) and to further understand the impacts of weaning age on gastrointestinal development. To meet these objectives, 108 Holstein bull calves (18.7±2.69 d old) were blocked by BW and randomly assigned to one of three treatments: step-down weaning at 8, 10 or 12 weeks of age. Daily milk replacer supply and refusals, and weekly starter and hay intakes were recorded throughout the 10 week experiment. Average daily gain (kg d−1) and BW (kg) were measured weekly. Digestive tract development was assessed by sampling blood and fecal matter at 5, 7, 9, 11 and 13 weeks of age. Blood was analysed for βHBA as a marker of rumen development (ruminal ketogenesis) and fecal starch content was used to evaluate its total tract digestibility. Intakes of starter were higher in calves weaned at 8 weeks of age, from week 7 onwards, translating into differences in total starter consumption across the 10 week trial (P<0.01). Weekly differences occurred in ADG (P<0.05) during the weeks of weaning, resulting in differences in final BW and total weight gain between calves weaned at 8 and 12 weeks of age. No differences were observed in fecal starch content (P>0.05), yet, βHBA presented smaller spikes at weaning with increasing weaning age (P<0.01), indicating that older animals may experience a less abrupt activation of rumen function. Overall, the results suggest that delaying weaning of calves fed an elevated plane of nutrition may be beneficial to sustain growth performance and avoid stress during weaning.

Feeding milk replacer instead of whole milk affects blood plasma proteome and lipid profile in preruminant calves.

The study was undertaken to determine the effect of feeding milk or milk-replacer on the blood plasma proteome and lipid profile in calves during the second week of life. Feeding milk-replacer significantly decreased the expression of plasma apoA-I. Age of calves affected apoA-I expression, which was higher on the 8th than on the 11th and 14th day of life. A significant effect of interaction between diet and age was also observed. The expression of apoA-IV, was significantly affected by diet and was lower in calves fed milk replacer. Expression of this protein was significantly lower at the 8th day of life and was up-regulated in the calves fed milk-replacer at the second week of life. Calves fed milk-replacer had greater expression of haptoglobin, which differed significantly between days of blood sampling, being higher on the 8th than on the 11th and 14th day. The interactive effect of diet and age affected haptoglobin expression, which was successively down-regulated in calves fed milk re- placer. Diet had a significant effect on the plasma lipid profile. Animals fed milk had a greater concentration of TC, HDLC and LDLC. The composition of milk-replacer, especially fat source, is probably the main factor that affects expression of proteins involved in cholesterol metabolism and level of components of lipid profile in calves fed formula. We claim that the initially increased level of haptoglobin, followed by its decrease during the second week of life in calves fed milk-replacer may indicate the presence of short-term stress induced by changes in the feeding system.

A longitudinal field trial assesing the impact of feeding waste milk containing antibiotic residues on the prevalence of ESBL-producing Escherichia coli in calves

A longitudinal field trial was carried out on a farm known to harbour cefotaximase (CTX-M)-positive Escherichia coli, in order to assess the impact of feeding waste milk containing antibiotic residues (WM+AR) on the prevalence of these bacteria in the faeces of calves. Fifty calves were alternately assigned to one of two groups at birth and fed either milk replacer (control group) or WM+AR (treatment group). Faecal samples were collected from all calves daily for the first week after enrolment, twice weekly until weaning, then weekly for a further six weeks. Environmental samples from the calf housing were collected weekly. WM+AR and powdered milk samples were examined for antibiotic residues and CTX-M-positive E. coli. Total E. coli and CTX-M-positive E. coli in faecal samples were enumerated using selective media. Regression analyses were performed on the bacterial count data using a population-averaged approach based on generalised estimating equations (GEE) to account for repeated measurements on individual calves over time.Cefquinome, a fourth generation cephalosporin, was detected in 87% of WM+AR samples at a mean concentration of 0.746mg/l. All environmental sampling locations yielded CTX-M-positive E. coli. Significantly more pen floor samples were positive in the treatment group. Calves in the treatment group shed greater numbers of CTX-M-positive E. coli than calves in the control group throughout the study, and shedding decreased at a slower rate in the treatment group. CTX-M-positive E. coli persisted in a larger number of calves fed WM+AR compared with calves fed milk replacer where the prevalence in the treatment group declined significantly slower over time. There was no difference between calves fed WM+AR or calves fed milk replacer in the proportion of E. coli isolates that were CTX-M-positive.These findings indicate that feeding WM+AR increased the amount of resistant bacteria shed in the faeces. Shedding of CTX-M-positive E. coli persisted for longer in calves fed WM+AR, and persisted after weaning.

Urea Recycling Contributes to Nitrogen Retention in Calves Fed Milk Replacer and Low-Protein Solid Feed

Urea recycling, with urea originating from catabolism of amino acids and hepatic detoxification of ammonia, is particularly relevant for ruminant animals, in which microbial protein contributes substantially to the metabolizable protein supply. However, the quantitative contribution of urea recycling to protein anabolism in calves during the transition from preruminants (milk-fed calves) to ruminants [solid feed (SF)–fed calves] is unknown. The aim of this study was to quantify urea recycling in milk-fed calves when provided with low-protein SF. Forty-eight calves [164 ± 1.6 kg body weight (BW)] were assigned to 1 of 4 SF levels [0, 9, 18, and 27 g of dry matter (DM) SF · kg BW−0.75 · d−1] provided in addition to an identical amount of milk replacer. Urea recycling was quantified after a 24-h intravenous infusion of [15N2]urea by analyzing urea isotopomers in 68-h fecal and urinary collections. Real-time qPCR was used to measure gene expression levels of bovine urea transporter B (bUTB) and aquaglyceroporin-3 and aquaglyceroporin-7 in rumen wall tissues. For every incremental gram of DM SF intake (g DM · kg0.75), nitrogen intake increased by 0.70 g, and nitrogen retention increased by 0.55 g (P < 0.01). Of this increase in nitrogen retention, 19% could be directly explained by urea recycling. Additionally, part of the observed increase in nitrogen retention could be explained by the extra protein provided by the SF and likely by a greater efficiency of postabsorptive use of nitrogen for gain. Ruminal bUTB abundance increased (P < 0.01) with SF provision. Aquaglyceroporin-3 expression increased (P < 0.01) with SF intake, but aquaglyceroporin-7 expression did not. We conclude that in addition to the increase in digested nitrogen, urea recycling contributes to the observed increase in nitrogen retention with increasing SF intake in milk-fed calves. Furthermore, ruminal bUTB and aquaglyceroporin-3 expression are upregulated with SF intake, which might be associated with urea recycling.

Effects of cellooligosaccharide or a combination of cellooligosaccharide and live Clostridium butyricum culture on performance and intestinal ecology in Holstein calves fed milk or milk replacer

The effects of oral administration of a prebiotic (cellooligosaccharide [CE]) and a combination of a probiotic (a commercial Clostridium butyricum strain) and prebiotics (referred to as symbiotics [SB]) on performance and intestinal ecology in Holstein calves fed milk replacer (MR) or whole milk were evaluated. Forty female calves (experiment 1) and 14 male and female calves (experiment 2) were used in this study. Calves were fed MR (experiment 1) or whole milk (experiment 2) necessary for daily weight gain of 0.3kg based on birth weight in two daily feedings and weaned at 46 days. Calves were divided into a CE feeding group, SB feeding group (only in experiment 1), and control group. The CE and SB groups were fed CE at 5g/day before weaning and 10g/day postweaning. Only the SB group received 108 colony-forming units (CFU) of C. butyricum culture per day. Commercial calf starter was offered for ad libitum intake. Health and feed intake of the animals were monitored daily, and body weight was measured weekly. Fecal samples were analyzed for determination of bacterial community composition by an RNA-based method (sequence-specific SSU rRNA cleavage method) and for organic acid profiling. In 49-day experiments, feed intake, daily gain, and occurrence of diarrhea of the calves were unaffected by either CE supplementation or SB supplementation, and all calves were healthy during each experiment. The fecal bacterial community compositions and the organic acid profiles were not different among groups in experiment 1. In experiment 2, the level of the Clostridium coccoides–Eubacterium rectale group was higher in the feces of CE group than controls at 4 weeks of age and fecal butyric acid concentration was higher (8.0 vs. 12.2 [mmol/kg feces], P<0.05) at that time. There were no differences in prebiotic bacteria (the genera Lactobacillus and Bifidobacterium) between groups at this time point. These results suggested that CE and C. butyricum supplementation have less effect on the performance of healthy calves fed MR. However, prebiotic supplementation seems effective for modulation of the intestinal bacterial community of calves when administered with whole milk.

The limiting sequence and proper ratio of lysine, methionine and threonine for calves fed milk replacers containing soy protein.

The limiting sequence and relative ratio of lysine (Lys), methionine (Met), and threonine (Thr) for calves about 2 mo of age fed milk replacers (MR) containing soy protein are not clearly defined. The objective of the study was to investigate the effect of supplementing MR containing 22% CP, half from soy protein concentrate (SPC, 40.56% CP, flour) and half from whey proteins, with Lys, Met, and Thr to estimate amino acid (AA) sequence and their relative ratio for calves about 2 mo of age. A method of partial deduction of AA was adopted. Twenty-four newborn calves (half males and half females, 40.7±0.9 kg of BW) were fed 1 of 4 MR diets for 56 d (n = 6/diet). The diets were supplemented with all (positive control) or with 2 of the 3 AAs: Lys, Met and Thr, (i.e., PC (22% CP, 2.34% Lys, 0.72% Met and 1.80% Thr), PC-Lys (22% CP, 1.64% Lys, 0.72% Met and 1.80% Thr), PC-Met (22% CP, 2.34% Lys, 0.50% Met and 1.80% Thr), and PC-Thr (22% CP, 2.34% Lys, 0.72% Met and 1.26% Thr)). Calves were fed thrice daily; starter (20% CP, 1.03% Lys, 0.30% Met and 0.69% Thr), hay (3.23% CP, 0.29% Lys, 0.12% Met and 0.23% Thr) and water were offered free choice. Starter and hay were only offered beginning on d 36 (after 5 wk) and d 43 (after 6 wk), respectively. BW, body size and blood samples measures were taken every two weeks. Three-day total collection of feed refusals, feces, and urine were recorded starting at d 33 and d 54 of age, respectively. From the results, the limiting sequence and relative ratio between the 3 AAs in calves with different diet structures were calculated. The limiting sequence of the 3 AAs were ranked as Lys, Met and Thr; the proper ratio was 100:29:70 for MR-only diet and 100:30:60 for diets consisted of MR, starter and hay. Nitrogen digestion and utilization and nutrient digestibility were negatively affected by AA deletion treatments. From the evidence of this experiment, it did not appear that the AA limiting sequence was selectively altered by differences in diet structures such as would be encountered in practice. The relative ratio between the 3 AAs varied with the offer of starter and hay to calves, and the average ratio was 100:29.5:65 for calves during 2 to 10 wk of age.

Characterization of the rumen microbiota of pre‐ruminant calves using metagenomic tools

The temporal sequence of microbial establishment in the rumen of the neonatal ruminant has important ecological and pathophysiological implications. In this study, we characterized the rumen microbiota of pre-ruminant calves fed milk replacer using two approaches, pyrosequencing of hypervariable V3-V5 regions of the 16S rRNA gene and whole-genome shotgun approach. Fifteen bacterial phyla were identified in the microbiota of pre-ruminant calves. Bacteroidetes was the predominant phylum in the rumen microbiota of 42-day-old calves, representing 74.8% of the 16S sequences, followed by Firmicutes (12.0%), Proteobacteria (10.4%), Verrucomicrobia (1.2%) and Synergistetes (1.1%). However, the phylum-level composition of 14-day-old calves was distinctly different. A total of 170 bacterial genera were identified while the core microbiome of pre-ruminant calves included 45 genera. Rumen development seemingly had a significant impact on microbial diversity. The dazzling functional diversity of the rumen microbiota was reflected by identification of 8298 Pfam and 3670 COG protein families. The rumen microbiota of pre-ruminant calves displayed a considerable compositional heterogeneity during early development. This is evidenced by a profound difference in rumen microbial composition between the two age groups. However, all functional classes between the two age groups had a remarkably similar assignment, suggesting that rumen microbial communities of pre-ruminant calves maintained a stable function and metabolic potentials while their phylogenetic composition fluctuated greatly. The presence of all major types of rumen microorganisms suggests that the rumen of pre-ruminant calves may not be rudimentary. Our results provide insight into rumen microbiota dynamics and will facilitate efforts in formulating optimal early-weaning strategies.

Comparative Study of Selected Blood Biochemical Components in Milk or Milk-Replacer Fed Calves during the Second Week of Life

The experiment was carried out on 13 male Polish Black and White dairy calves of 75% share of the Holstein-Friesian (HF) breed during the second week of life. The animals were divided into two groups. One group (n=7) was fed mother's milk and the second (n=6) milk replacer. The dynamics of changes in concentration of selected blood biochemical components connected with nitrogen metabolism (plasma total protein, albumin, urea, endogenous creatinine) and with mineral metabolism (sodium, chloride, calcium, magnesium, zinc, copper and plasma osmotic pressure) were analyzed in both groups. The results show that the type of ingested food influences the concentration of indicators reflecting nitrogen metabolism. Changes of these parameters in calves fed milk replacer are possibly connected with advantageous catabolic changes. Stable concentrations of main extracellular fluid electrolytes and blood plasma osmotic pressure were found in both groups of calves. Constant blood plasma calcium, magnesium, zinc and copper concentrations observed during this study might also indicate the relative maturity of mechanisms maintaining water and electrolyte balance. Nevertheless, it seemsjustifiable to monitor the copper concentrations in plasma of young calves.

Effects of including corn distillers dried grains with solubles in dairy calf feeds

A series of 5 trials was conducted to determine the effect of distillers dried grains with solubles (DG) in calf diets. Trial 1 compared 0 or 49% DG in 18% crude protein (CP) starters (as-fed basis) fed to calves initially 2 to 3 d old for 56 d. Digestibility was estimated during d 52 to 56 using chromic oxide. Trial 2 compared 0 or 39% DG in 16% CP growers fed to calves from 8 to 12 wk of age from 28 d. Trial 3 compared 0, 10, or 20% DG in 18% CP starters fed to calves initially 2 to 3 d old for 56 d. Trial 4 compared 0 or 20% DG in 16% CP growers fed to calves from 8 to 12 wk of age from 28 d. As DG increased in all diets, acid detergent fiber, neutral detergent fiber, and fat increased and calculated metabolizable energy was similar but not equalized. In trials 1 and 3, calves (n=48/trial) housed in individual pens were fed 26% CP, 17% fat milk replacer powder and weaned at 28 d. Trials 2 and 4 used calves (n=48/trial) housed in group pens (6 calves/pen) that had been weaned for 28 d before the trials’ start. Trial 5 (n=18 calves) had the same starter treatments as trial 3 fed in combination with high or low milk replacer intake, with calves killed at 35 d to determine effects of DG and milk replacer intake on rumen development. In trial 1, average daily gain (ADG) was 6% greater and dry matter digestibility was 10% greater for calves fed 0% versus 49% DG. In trial 2, ADG (9%), feed efficiency (10%), and hip width change (19%) were greater for calves fed 0% versus 39% DG. Performance measures did not differ among starter treatments in Trials 3 and 5. In trial 4, ADG (4%), feed efficiency (5%), and hip width change (19%) were greater for calves fed 0% versus 20% DG. In trial 5, rumen development was not affected by DG inclusion, but was greater for calves fed milk replacer at 630 versus 940g/d, which had greater starter intake. Overall, we conclude that high levels of distillers in calf starters and growers decrease growth of calves; however, starters with ≤20% DG allow for normal growth rates and rumen development.

Lactic acid bacteria to improve growth performance in young calves fed milk replacer and spray-dried whey powder

Healthy calves have a balanced intestinal microbiota that allows them to grow adequately. Use of microorganisms with probiotic capacity is an alternative method for treatment and prevention of some bovine diseases. Incorporation of probiotics in young calf diets prevents the occurrence of possible imbalances in the normal microbiota in the intestinal tract and contributes to improved growth of young calves housed under stressful conditions by preventing diarrhea. In this study, effects of a lactic acid bacterial inoculum of bovine origin composed of Lactobacillus casei DSPV 318T, Lactobacillus salivarius DSPV 315T and Pediococcus acidilactici DSPV 006T was evaluated by measuring growth performance and health state of young calves fed milk replacer and spray-dried whey powder. The inoculum with three microorganisms suspended in 0.15 M NaCl was orally administered to an experimental group of calves, on a 10 9 CFU/kg live weight daily dose for 35 days. The control group was administered only an NaCl solution as placebo. The diet consisted of 4 l/d milk replacer (110 g dry matter/l), supplemented with 200 g spray-dried whey powder. The microbial inoculum was examined in an experimental model with young calves fed milk replacer and a large quantity of spray-dried whey powder to generate an intestinal imbalance. Under these conditions, the inoculum promoted earlier consumption of starter and, indirectly, may have stimulated earlier development of the rumen, omasum and reticulum, thus favoring early weaning. Inoculated calves had better growth performance, which could be related to a better digestion of lactose and spray-dried whey proteins, which justifies use of the inoculum with the spray-dried whey powder during calf rearing since it will reduce production costs and favor system sustainability.

Colostrum and Milk as Risk Factors for Infection with Mycobacterium avium subspecies paratuberculosis in Dairy Cattle

Mycobacterium avium ssp. paratuberculosis (MAP) infections cause major losses to the dairy industry. Transmission of MAP occurs primarily via feces and in utero, but MAP can also be excreted in colostrum and milk. The objective of this study was to determine whether colostrum and milk fed to calves are important risk factors for infection with MAP. A questionnaire was sent to 1,050 farms participating in the Danish control program on paratuberculosis in early 2007. Details on practices regarding colostrum and milk feeding between 1999 and 2006 were obtained from 808 (77%) herds. Nine vaccinated herds were excluded. Information on MAP antibody-ELISA results, date of birth, and herd of birth of 93,994 animals was obtained from the Danish Cattle Database. A 2-level logistic regression model was fitted with a dichotomized ELISA response, with outcome, age, source of colostrum, and milk as fixed effects, and herd as a random effect. Animals fed colostrum from multiple cows had an odds ratio of 1.24 of being ELISA positive compared with animals fed colostrum from their own dam only. Calves suckling with foster cows had an odds ratio of 2.01 of being ELISA positive compared with calves fed milk replacer. Feeding bulk tank milk and pooled milk from cows with high somatic cell counts did not increase the risk of being ELISA positive. Overall, the results of the study suggested that source of milk was not of great importance for the transmission of MAP, but colostrum should be fed only from the dam of that calf.

Ultrasonographic imaging of abomasal curd in preruminant calves

The aim of this study was to determine whether ultrasonography could be used to evaluate curd formation in the abomasum of preruminant calves. Holstein–Friesian calves were fed one of three milk replacers: clotting (five calves), non-clotting (four calves) and pH-dependent clotting (clots form at pH 5.5, but not at pH 6.5; six calves). Ultrasonography was performed until 6 h after feeding the milk replacers. In calves fed the clotting milk replacer, a large clot of curd was visualised by ultrasonography as a clearly outlined echogenic image and whey as an anechoic image. In calves fed the non-clotting milk replacer, abomasal contents were visualised as a uniform, entirely echogenic image, indicating the absence of curd formation. In calves fed milk replacer with pH-dependent clotting properties, several small curds and whey were visualised by ultrasonography. It was concluded ultrasonography can be used to visualise abomasal curd and to distinguish the presence and absence of curds in the abomasum of calves.