Calves Fed Milk Replacer Research Articles

Growth performance of neonatal calves fed milk replacer 2 vs. 3 times per day.

Several calf studies demonstrated growth advantages when feeding greater protein and/or milk solids amounts, however, studies comparing 2 times per day vs. 3 times per day feeding are limited. The study objective was to evaluate feeding 2 times per day vs. 3 times per day thereby increasing milk solids intake. Forty 2- to 5-d old Holstein bull calves were blocked by body weight (BW) and randomly assigned to 1 of 2 treatments (N = 20/treatment) using a randomized complete block design. Treatments were 1) 2×: milk replacer (MR) fed 2 times per day; and 2) 3×: MR fed 3 times per day for increased solids intake. The MR was fed at 15% solids at 0630 and 1800 hours and the 3rd 3× feeding was at 1200 hours. Calves on 2× were fed MR at 0.567 kg/d for days 1 to 14, increased to 0.85 kg/d for days 15 to 35, and reduced to 1 time per day at 0.425 kg/d for days 36 to 42 to facilitate weaning at 42 d. Calves on 3× were fed MR 0.851 kg/d for days 1 to 14, increased to 1.275 kg/d for days 15 to 35, and reduced to 1 time per day at 0.425 kg/d for days 36 to 42 followed by weaning. Calf starter (CS; amounts and orts weighed daily) and water were offered for ad libitum intake. Initial BW was not a significant covariate and final BW (81.5 and 80.9 kg, for 2× and 3×, respectively) was similar. A treatment-by-week interaction (P < 0.01) indicated variable BW gains during the study with calves fed 3× demonstrating greater BW during weeks 4 (P < 0.10) and 5 (P < 0.05) compared with calves fed 2×. However, BW gains for calves fed 3× were reduced (P < 0.05) during the weaning period resulting in similar BW gains (36.8 and 36.4 kg) at the study end. Intake of CS (0.65 and 0.46 kg/d) was lower (P < 0.04) for calves fed 3× compared with calves fed 2×. Feed conversions (0.64 and 0.58 kg/kg) were greater (P < 0.02) for calves fed 2× compared with 3× fed calves. Calves fed 2× had less (P < 0.01) scours (fecal score = 0; 34.3 and 29.7 d) compared with 3× fed calves. Providing an additional MR feeding demonstrated minimal BW gains due to lower CS intake. Providing greater MR intake using a 3rd daily feeding reduces CS intake that can inhibit transition to dry feed when weaning calves.

PSVI-1 Supplemented milk replacer improves feed transition of dairy bull-calves

Abstract Neonatal calves are affected by pathogenic infections, compounded by stress, leading to enteric and respiratory disorders accounting for about 7.8% mortality rate and annual treatment costs exceeding $250 million. Federal restrictions on antibiotic use due antimicrobial resistance in humans has opened the door for viable alternatives like rumen enhancements which have been reported to aid the establishment of beneficial rumen flora leading to improved health and performance. It is hypothesized that nutritional formulation of milk replacers to help the calf prevent or cope with diarrhea can provide a leeway that will ensure better animal performance and transition to solid feed. The objective of study was to evaluate the performance of dairy bull-calves fed nutritionally supplemented milk replacers. Three milk replacers were tested with or without supplementation of metabolic enhancements (Control: no metabolic enhancer; Added: milk replacer with metabolic enhancer added at the time of mixing milk in shuttle; Composite: produced along with metabolic enhancer. Dairy bull-calves (n = 60; 2 to 5 d-old) were grouped into three treatments of milk replacers. The study lasted for 10 wk; 6 wk of milk-feeding and 4 wk of calf starter feeding. Body weights (BW) were taken on a weekly basis, while calf starter intake was measured daily and data were analyzed using one-way analysis of variance. Calves fed milk replacer with composite metabolic enhancer recorded the greatest intake and final BW over the 10-wk period. Calves fed milk replacer with added metabolic enhancer at the point of milk mixing recorded the poorest data in terms of BW gain and final BW. Calves fed metabolic enhancer, either added or composite recorded a better weaning and transition to solid feed from milk feeding. Calves fed control milk replacer experienced a poor transition from milk feeding to solid feed. It is concluded that composited rumen metabolite enhancers in milk replacer supported greater starter intake, average daily gain and better transition of calves to solid feed, and is recommended for the feeding of neonatal calves.

Serum lipidomic profiling of dairy calves fed milk replacers containing animal or vegetable fats

Vegetable fat blends are commonly used as fat sources in milk replacers (MR) for calves, but their composition differs considerably from that of bovine milk fat. The aim of this study was to investigate the serum lipid profile of pre-weaned calves fed twice-daily MR containing 30% fat (% DM). Upon arrival, 30 male Holstein-Friesian calves (BW = 45.6 ± 4.0 kg, age = 2.29 ± 0.8 d) were randomly assigned to 2 experimental diets (n = 15 per treatment): one MR was derived from either vegetable fats (VG; 80% rapeseed and 20% coconut fats) or animal fats (AN; 65% Packer's lard and 35% dairy cream). The 2 MR formulas contained 30% fat, 24% CP, and 36% lactose. Calves were housed indoors in individual pens with ad libitum access to chopped straw and water. 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 13.5% solids. An untargeted liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) method was employed to analyze the lipid profiles in the serum of calves sampled from the jugular vein at 35 d of age. In total, 594 lipids were characterized, comprising 25 different lipid classes. Principal component analysis (PCA) showed significant separation between VG and AN, indicating different lipid profiles in the serum. An orthogonal partial least squares discriminant analysis (OPLS-DA) classification model was used to further validate the distinction between the 2 treatment groups. The model exhibited a robust class separation and high predictive accuracy. Using a Volcano plot (fold change threshold ≥1.5 and false discovery rate ≤0.05), it was observed that calves fed AN had higher levels of 39 lipid species in serum than calves fed VG, whereas 171 lipid species were lower in the AN group. Lipid classes, such as phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (SM), triglycerides (TG), lysophosphatidylcholine (LPC), and lysophosphatidylethanolamine (LPE), were different. In particular, PC and PE were observed at lower levels in calves fed AN, possibly indicating shifts in cell membrane characteristics, intracellular signaling, and liver functions. In addition, a decrease in certain triglyceride (TG) species was observed in calves fed AN, including a decrease in TG species such as TG 36:0 and TG 38:0, possibly related to variations in the content of certain fatty acids (FA) within the AN MR, such as C10:0, C12:0, C14:0, and C18:0 compared with the VG MR. Calves fed AN had lower levels of LPC and LPE, and lyso-phosphatidylinositol (LPI), SM, and phosphatidylinositol (PI) species than calves fed VG, suggesting shifts in lipoprotein and lipid metabolic pathways. In conclusion, these results deepen the understanding of how lipid sources in MR can modulate the serum lipidome profiles of dairy calves.

Effects of tributyrin supplementation in calf starter on growth, blood parameters and development of rumen and small intestine in Holstein calves fed milk replacers with different fatty acid profile

The objective of this study was to evaluate the effects of tributyrin (TB) supplementation in calf starter on development of the rumen and small intestine for calves fed two milk replacers differing in fatty acid composition. Fifty-four Holstein calves (38 heifers and 16 bull calves) were assigned to one of the four treatments: (1) milk replacer containing 31 g/kg C8:0 and 29 g/kg C10:0 in total fatty acids (MR-) and calf starter without TB (ST-) (MR-ST-; n = 14), (2) MR- and calf starter with a TB supplement (600 g/kg TB and 400 g/kg silicon dioxide) at 6 g/kg of DM (ST+) (MR-ST+; n = 13), (3) milk replacer containing 26 g/kg C4:0, 57 g/kg C8:0, and 56 g/kg C10:0 in total fatty acids (MR+) and ST- (MR+ST-; n = 13), and (4) MR+ and ST+ (MR+ST+; n = 14). Milk replacers were offered at 600 g/d (powder basis) from 8 to 14 d, increased up to 1300 g/d from 15 to 21 d, 1400 g/d from 22 to 49 d, decreased down to 700 g/d from 50 to 56 d, and 600 g/d from 57 to 63 d, and then weaned at 64 d of age. Data and samples were collected until 91 d of age. All the calves were fed one of the calf starters and chopped hay ad libitum from 8 d of age. Bull calves were euthanized at weaning to determine weights of digestive organs and evaluate ruminal and small intestinal morphology. Calf starter and milk replacer treatments did not affect dry matter intake, growth performance, digestive organs weights (kg/100 kg of body weight), and rumen papillae length. However, calves fed ST+ had greater ratio of villus height to crypt depth (2.20 vs. 1.84; P < 0.01) in the ileum compared to those fed ST-. In addition, calves fed MR+ had less crypt depth (240 vs. 298 µm; P = 0.02) and greater ratio of villus height to crypt depth (2.22 vs. 1.91; P < 0.01) in the ileum compared to those fed MR-. A tendency for interaction between milk replacer and calf starter treatments was observed for the ratio of villus height to crypt depth in the jejunum, in which TB in calf starter increased the ratio only for calves fed MR-. Milk replacer treatment did not affect plasma glucagon-like peptide-2 (GLP-2) concentration. However, calves fed ST+ had greater plasma GLP-2 concentration compared to those fed ST- after weaning (1.16 vs. 0.80 ng/mL; P < 0.02). These results suggest that TB supplementation for dairy calves may affect small intestinal morphology at weaning, and increase plasma GLP-2 concentration after weaning.

334 Use of Feed Additives in Unweaned Calves with Compromised Gut Integrity After Transportation

Abstract The gastrointestinal tract of unweaned calves is compromised after the stress and feed restriction due to marketing and transportation. The use of feed additives to enhance intake and gut immunity at farm arrival could be a strategy to minimize those negative effects. A total of 70 dairy beef calves (50.9 ± 1.66 kg) coming from auction market and with a compromised gut integrity at arrival were used to evaluate the effect of various feed additives [FA; comprising palatability enhancers (PE), standardized olive pomace extract (OE), and tributyrin (TB)] on performance until 2 weeks after weaning. Calves were distributed in 5 treatments: calves fed milk replacer (MR) and concentrate without FA (CTR; n = 14); calves fed MR and concentrate with PE (PE; n = 14); calves fed MR with OE + PE and concentrate with PE (OEPE; n = 14), calves fed MR with TB + PE and concentrate with PE (TBPE; n = 14); and calves fed MR with OE + TB + PE and concentrate with PE (complete - COM; n = 14). At arrival animals received 2.5 L of MR twice daily at 12.5% and ad libitum concentrate feed. On day 35 of the study, animals were submitted to a social stress challenge, calves within one treatment were mixed for 24 h, and on day 36, calves returned to their home pens and the afternoon milk was removed. On day 42, all calves were weaned, and they were followed until day 56. Data were analyzed with a mixed-effects model. After transportation calves had an average of 1.6 ± 0.09 mg/L of serum Cr-EDTA the first week after arrival indicating that those calves had increased gastrointestinal permeability and a compromised gut barrier for a full week; consequently, concentrate intake during that week was decreased for all treatments (P = 0.56) with an average of 27 g·calf-1·d-1. An interaction between treatment and time (P &amp;lt; 0.01) was observed on concentrate intake the last two weeks of the study when calves were already weaned; on week 7, from day 42 to d 49, COM and TBPE calves had greater concentrate intake than CTR calves, and PE and OEPE did not differ among others; and on week 8, between day 42 and day 49, COM calves had the greater concentrate intake than CTR, while other treatments were in between. Although only numerical differences were observed in final BW, COM calves were heavier than the rest of the treatments at the end of the study. In calves with severe problems of gastrointestinal permeability at arrival, the mixture of palatability enhancers, standardized olive pomace extract, and tributyrin increases concentrate intake and potentially improve the recovery of the animals.

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.

Effects of oral or parenteral iron supplementation on haematological parameters, blood iron status and growth in newborn calves fed milk replacer.

This study aimed to assess the influence of early life iron supplementation on the haematological parameters of calves fed milk replacer on a high plane of nutrition. Thirty calves were allocated to receive either a sham treatment (CON), injection of 1000mg Fe3+ (INJ) or oral administration of 1050mg Fe3+ (ORAL), all administered less than 1hour after birth. Blood was obtained before treatment, on days 1, 3, 5 and 7 of life and once weekly until week 9. Samples were analysed for haemoglobin (Hb), packed cell volume (PCV) and estimated transferrin saturation (%TSAT). The Hb and PCV of calves in the INJ and ORAL groups were above the values of those in the CON group throughout the study. Hb and PCV of the CON group remained within the reference range for calves. The %TSAT exceeded reported ranges in theORAL group in the first week. Values for the CON group were below the INJ and ORAL groups throughout the entire study. Average daily gain did not differ between treatments. The sample size was insufficient to assess the influence of iron supplementation on disease development. Furthermore, the study was set in a controlled environment and not performed under field conditions. Oral and subcutaneous iron administration had similar effects on haematological development but resulted in numerically different transferrin saturation. Control animals showed lower Hb and PCV but did not develop overt anaemia.

Effects of supplementing milk replacer with essential amino acids on blood metabolites, immune response, and nitrogen metabolism of Holstein calves exposed to an endotoxin

This study evaluated the effects of supplementing calf milk replacer with essential AA on immune responses, blood metabolites, and nitrogen metabolism of 32 Holstein bull calves [28 d of age, 44 ± 0.8 kg of body weight (BW)] exposed to lipopolysaccharide (LPS). Calves were bottle-fed a commercial milk replacer (20% crude protein and 20% fat, dry matter basis) twice daily along with a calf starter (19% crude protein, dry matter basis) for 45 d. The experiment was a randomized complete block design and treatments were a 2 × 2 factorial arrangement. Treatments were milk replacer (fed twice daily at 0.5 kg/d of powder) supplemented with or without 10 essential AA (+AA vs. -AA), and subcutaneous injection of sterile saline with or without LPS (+LPS vs. -LPS) at 3 h after the morning feeding on d 15 (4 µg LPS per kg of BW) and 17 (2 µg LPS per kg of BW). Calves also received a 2-mL subcutaneous injection of ovalbumin (6 mg of ovalbumin/mL) on d 16 and 30. Rectal temperature and blood samples were collected on d 15 before LPS injection and at h 4, 8, 12, and 24 thereafter. From d 15 to 19, total fecal and urinary output were collected, and feed refusals were documented. Rectal temperature was greater in +LPS than -LPS calves at h 4, 8, and 12 after LPS injection. Serum cortisol was greater for +LPS than -LPS at h 4 after LPS exposure. At d 28, serum antiovalbumin IgG level was greater in +LPS +AA calves compared with +LPS -AA. Serum glucose was lower for +LPS than -LPS at h 4 and 8. Serum insulin was greater in +LPS than -LPS calves. Plasma concentrations of Thr, Gly, Asn, Ser, and hydroxyproline were lower for +LPS versus -LPS calves. Plasma concentrations of Met, Leu, Phe, His, Ile, Trp, Thr, and Orn were greater in +AA calves than -AA calves. Plasma urea N and N retention were not different among LPS and AA treatments. The lower concentrations of AA in +LPS than -LPS calves indicate higher demand for AA in immuno-compromised calves fed milk replacer. Additionally, higher concentration of ovalbumin-specific IgG level in +LPS calves supplemented with +AA compared with +LPS calves with -AA suggests that supplementing AA to immune-compromised calves might improve immune status.

Does the upper respiratory tract microbiome change in dairy calves fed milk replacer containing probiotics?

Abstract Our overall hypothesis is that feeding probiotics to dairy calves will alter overall immunity and may additionally change the microbiome in the respiratory tract as well as the gut. A group of 20 dairy calves were split into two treatment groups: Control (N=10, milk replacer), and Probiotic (N=10, milk replacer + 0.5 g/day Bovamine Dairy). On day 0 birth weight was obtained and the calves were provided colostrum as per the dairy SOP. On day 2, probiotics were added to the milk replacer of the treated group. Blood was collected along with nasal and tonsil swabs on days 0, 7, 14, 21, 28, 42, and 48. Calves were monitored daily for fecal, nasal, and ocular discharge scores. Our preliminary data showed no significant differences (P&amp;lt;0.5) between the Control and Probiotic groups in immune cell populations in peripheral blood. DNA was extracted from nasal and tonsil swabs to evaluate the bacterial populations in the upper respiratory microbiome. Hypervariable regions 1 through 3 along the 16S ribosomal RNA gene were amplified by PCR and sequenced by Illumina MiSeq to determine the bacterial taxa present. Evaluation of these samples revealed a greater percentage of operational taxonomy units (OTU) were classified at the genus level in the tonsil compared to the nasal samples. The microbiome of the tonsils was more stable over time points compared to the nasal samples. Evaluation of each timepoint for nasal and tonsil samples identified bacterial taxa that changed in relative abundance with the addition of the probiotic compared to the control diet. Addition of probiotic changed the relative abundance of OTU (P&amp;lt;0.01) in the nasal and tonsil sampling sites and at multiple timepoints. Analyses are ongoing. Project supported by fund from the USDA Agricultural Research Service.

Tributyrin administration improves intestinal development and health in pre-weaned dairy calves fed milk replacer.

Butyrate and its derivatives possess various nutritional and biological benefits for mammals, whereas its effects on dairy calves have not been well characterized. This study evaluated the effects of tributyrin administration on blood immune, intestinal immune and barrier functions, and microbial composition of pre-weaned dairy calves. Twenty newborn Holstein bull calves were randomly assigned into a control group (no tributyrin supplementation, CON; n = 10) or a treatment group (supplemented with tributyrin at 2 g/L of milk, TRB; n = 10). The results showed that diarrhea frequency was decreased significantly by tributyrin administration from d 29 to 56 (P < 0.001) and the whole period (P = 0.003, d 1 to 56) though no significant effects were observed on growth performance. For blood metabolites, tributyrin administration significantly reduced the concentration of interleukin-1β (IL-1β) on d 28 (P = 0.001) and tended to reduce the concentration of serum amyloid A on d 56 (P = 0.079), whereas serum oxidative status parameters were not affected. For intestinal development, tributyrin administration increased the villus height (P < 0.001) and the ratio of villus height to crypt depth (P = 0.046) in the jejunum, and the villus height in the ileum (P = 0.074). Furthermore, toll-like receptor 2 (TRL2, P = 0.045) and IL-1β (P = 0.088) gene expressions were downregulated, while claudin-4 (P = 0.022) gene expression was upregulated in the jejunum following tributyrin administration. In the ileum, claudin-4 (P = 0.029) and G-protein coupled receptor 41 (P = 0.019) gene expressions were upregulated in the TRB group compared to CON. No significantly higher abundances of microbiota were found in the jejunum or ileum of calves in the CON group. In the TRB group, supplementing tributyrin significantly increased the abundance of short-chain fatty acid (SCFA)-producing bacteria, including Ruminococcaceae, Lachnospiraceae, Prevotella and Rikenellaceae (LDA >3.5, P < 0.05), which was negatively associated with inflammatory gene expression (TLR2 and IL-1β) but positively associated with intestinal barrier genes (claudin-4) and morphological parameters (P < 0.05). In conclusion, supplementing tributyrin in milk replacer could improve intestinal development and health of pre-weaned dairy calves by stimulating SCFA-producing bacteria colonization, enhancing intestinal barrier functions and suppressing inflammatory responses.

Effects of Supplemental Leucine on Growth, Nutrient Use, and Muscle and Visceral Tissue Mass in Holstein Bull Calves Fed Milk Replacer

To determine the effects of leucine supplementation on body weight (BW), tissue mass, nutrient digestibility, the concentration of serum amino acids (AAs) and metabolites, and protein abundance of elongation initiation factor 4E (eIF4E) in skeletal muscle, 23 Holstein bull calves (43. 3 ± 1.16 kg; 11.3 ± 0.57 days of age) fed milk replacer at 2.5% of body weight (BW; dry matter basis) were used in a randomized complete block design. Leucine was supplemented at 0, 0.4, 0.6, or 0.8 g Leu/kg BW per day for 28 d. Data were analyzed using the MIXED procedure of SAS. Leucine supplementation did not affect calf BW (P = 0.73), and digestibility of nitrogen (P = 0.21), organic matter (P = 0.28), and dry matter (P = 0.28). Masses proportional to BW of the pancreas (P = 0.04), omasum (P &amp;lt; 0.01), and spleen (P = 0.01) were quadratically affected by treatment where tissue mass decreased at 0.4 g Leu/kg BW and increased at 0.6 and 0.8 g Leu/kg BW. Semitendinosus mass proportional to BW tended (P = 0.07) to be quadratically affected, as tissue mass increased at 0.4 g Leu/kg BW, and decreased at 0.6 and 0.8 g Leu/kg BW. Serum Leu concentration increased linearly (P = 0.002; day × time × treatment) across days and after feedings with increased supplemental Leu. Increasing supplemental Leu linearly decreased serum Ala (P &amp;lt; 0.01), Arg (P = 0.04), Ile (P = 0.02), Met (P &amp;lt; 0.01), and Pro (P = 0.05) concentrations, and quadratically affected serum Glu (P = 0.04) and Lys (P = 0.03) concentrations where serum Glu and Lys concentrations were decreased at 0.4 g Leu/kg BW and increased at 0.6 and 0.8 g Leu/kg BW. There was no effect of treatment on protein abundance of eIF4E in semitendinosus or longissimus dorsi. These data indicate that supplemental Leu did not influence ADG and nitrogen retention in calves fed milk replacer. However, changes in serum AA concentrations and tissue masses proportional to BW suggest that supplementation of Leu at lower levels could increase the use of AA for non-visceral tissue growth.

A survey of calf management practices and farmer perceptions of calf housing in UK dairy herds

Adoption of optimal management techniques for rearing dairy calves has significant effects on their health, welfare, and productivity. Despite much published literature on best practice, calf morbidity and mortality rates remain high. This survey aimed to establish current calf management practices in the United Kingdom, along with farmer perceptions surrounding different housing types. A survey containing 48 questions was distributed online to UK farmers via social media, online forums, and a convenience sample of veterinary practices and was completed by 216 participants. A descriptive analysis with frequency distributions was calculated, with chi-squared tests, linear regression and multinomial regression performed to assess associations between variables. There was a low level of regular veterinary involvement in day-to-day health decision making for calves (3/216, 1.4%), highlighting the need for appropriate staff training and standard operating procedures to ensure prudent antimicrobial usage. Restricted calf milk feeding remains highly prevalent in the United Kingdom, with most calves fed milk replacer (114/216, 52.8%), twice daily (189/216, 87.5%), initially given milk at 4 L/d (66/216, 30.6%) or 6 L/d (47/216, 21.8%). There was, however, a small number of farmers initially feeding only 2 to 3 L/d (28/216, 13.0%). Euthanasia of bull calves (5/216, 2.3%) and feeding antimicrobial waste milk to calves (8/216, 3.7%) both occurred on some farms. With regard to housing, use of individual calf pens has reduced from around 60% in 2010 to 38.4% in this study (83/216), with this reduction being partly driven by the policy of UK milk buyers. Farmer perceptions indicated that individual housing was thought to help to improve calf health and feed monitoring of calves, suggesting that successful use of group housing requires a higher level of stockmanship. The majority of farmers did not provide fresh bedding to calves on a daily basis (141/216, 65.3%), and relatively few disinfected both the calf housing (38.0%) and ground (47.7%) between calves, suggesting that hygiene practices may require additional attention in farm management protocols.

47 Effects of Lactobacillus and Bacillus Probiotics on Pre-ruminating Calf Growth Performance and Efficiency

Abstract Lactobacillus and Bacillus probiotics may serve as an alternative to antibiotics in milk replacer for pre-ruminant calves by altering gastrointestinal microflora to prevent the proliferation of harmful bacteria. However, there are limited studies evaluating their impact on calf growth and efficiency. The objective of this trial was to discover the impact of probiotic-containing milk replacer on pre-ruminating calf growth performance. A total of 44 pre-ruminant calves (50% Angus/50% Holstein, average weight 39.3 kg + 7.5 kg) were fed milk replacer with either no probiotic or 1.25x10^9 colony forming units/head/day of a probiotic blending containing Lactobacillus and two different Bacillus species (Church &amp; Dwight Animal Nutrition (Princeton, NJ). Calves were blocked by age and randomly assigned within block to one of two treatments in a randomized complete block design. Calf was the experimental unit, with 22 calves per treatment. Calf weight and hip height was measured on d 0 and 30 to calculate average daily gain (ADG) and average growth per day. Calves were offered 1.36 kg milk replacer [15% dry matter (DM)] twice daily and up to 0.5 kg starter feed (88% DM) once daily. Refusals were recorded to calculate average daily intake and gain to feed ratio (G:F). Initial weight differed (P = 0.020) between treatments, and was therefore used as a covariate in all response criteria. Calves fed milk replacer with probiotic had greater (P &amp;lt; 0.05) ADG (0.53 vs. 0.42 kg/d, respectively) and G:F (0.50 vs. 0.41, respectively) than those fed the control. There was no evidence (P &amp;gt;0.05) that probiotic inclusion impacted hip height on d 30 or daily intake. In summary, Lactobacillus and Bacillus probiotic inclusion in milk replacer improved calf growth performance without impacting intake. Subsequent research is warranted to elucidate mode of action and evaluate impact relative to an antibiotic-containing positive control.

Effects of milk replacer meal size on feed intake, growth performance, and blood metabolites and hormones of calves fed milk replacer with or without butyrate ad libitum: A cluster-analytic approach

This study intended to classify ad libitum-fed calves according to their milk replacer (MR) meal size using the K-means clustering approach. This study aimed to investigate the effects of MR meal size on feed intake, growth performance, and blood metabolic and hormones of ad libitum MR-fed calves. German Holstein calves (16 male and 16 female) were studied from birth until d 77 of age. All calves received first colostrum (2.5 kg) milked from their dams within 2 h after birth. Subsequent colostrum meals (subsequent 4 meals until 2.5 d of age; 2 meals/d) and MR (125 g of powder/L; 21.7% crude protein, 18.6% crude fat) were fed ad libitum by teat bucket until d 10 ± 2 of age. Afterward, calves were housed in group pens with automatic feeders for MR (maximum of 25 L/d) and concentrate from 10 ± 3 d of age. Half of the calves received MR supplemented with butyrate to improve growth performance. Milk intake was stepped down to 2 L/d from wk 9 to 10, and 2 L/d of MR were offered until the end of the study. On d 1, 2, 4, and 7, and then weekly until wk 11 of age, blood samples were collected for measurement of metabolites and hormones related to energy metabolism and growth. The K-means cluster analysis on the MR meal size data collected from the automatic feeder resulted in 3 clusters (n = 14, n = 12, and n = 6). Two clusters with a sufficient cluster size (n = 14 and n = 12) were included for further statistical analysis using repeated measures mixed-model ANOVA. In both clusters, butyrate supplementation was equally distributed and failed to affect a difference in MR meal size. Cluster 1 showed calves with higher MR meal size (HI; 2.2 ± 0.11 L/visit of MR) and cluster 2 with lower meal size (LO; 1.8 ± 0.07 L/visit of MR) supplemented MR without (HIB-; n = 6; LOB-, n = 7) or with 0.33% calcium-sodium butyrate (HIB+; n = 6; LOB+, n = 7). Dry matter intake of MR did not differ between HI and LO, but intakes of concentrate and total dry matter tended to be greater in HI than in LO and increased more distinctly in HI than in LO at the end of the study. The average daily gain (g/d) was greater in HI than in LO. Plasma concentrations of total protein (g/L), albumin (g/L), glucose (mmol/L), urea (mmol/L), insulin (µg/L), and glucagon (ng/L) were higher, and the concentrations of insulin-like growth factor I tended to be higher, in HI than in LO calves. Plasma β-hydroxybutyrate was higher in LO than in HI at d 63 and lower in calves fed MR with butyrate at d 77. In conclusion, clustering analysis discriminates 2 main groups of calves with different MR meal size and indicates an effect of MR meal size on solid feed intake, growth performance, and metabolic changes.

Effect of prebiotic and probiotic supplements to increase live weight of calves in the diet

Article Details: Received: 2020-11-04 | Accepted: 2020-11-27 | Available online: 2021-01-31 https://doi.org/10.15414/afz.2021.24.mi-prap.164-167 Probiotics and prebiotics are effective to modulate optimal conditions in gastrointestinal tract inhabited by diverse microbial population. Probiotics regulate and modulate gut microbial population thus reducing the risk of diarrhea. Positive effect on growth is confirmed. The aim of this study was to evaluate the effect of probiotic ( Lactobacillus sporogenes ) and prebiotic ( Ascophyllum nodosum ) supplements on weight gain in calves. Forty new-born Holstein calves were randomised to control and experimental group. In the experimental group, Lactobacillus sporogenes and Ascophyllum nodosum were added first to colostrum and then to milk replacer, calves in the control group were fed with colostrum and milk replacer only. The weight gains of animals were found out during the whole experiment. Evidence of animal health and diarrhea was monitored. In the end of experiment, the body weight gains in experimental calves were by 14,4% higher compared to control but without statistical significance (P>0,05). Probiotic and prebiotic treatment tended to diminish diarrhea. The health benefits of monitored treatment were noticed in experimental group. Keywords: calf, dietary supplements, nutrition, health References Blum, J. W. (2006). Nutritional physiology of neonatal calves. Journal of Animal Physiology and Animal Nutrition , 90(1-2), 1-11. DOI: https://doi.org/10.1111/j.1439-0396.2005.00614.x Cangiano, T. T. et al. (2020). Invited Review: Strategic use of microbial-based probiotics and prebiotics in dairy calf rearing. Applied Animal Science , 36(5), 630-651. DOI: https://doi.org/10.15232/aas.2020-02049 Frizzo, L. S. etbal. (2010). Lactic acid bacteria to improve growth performance in young calves fed milk replacer and spray-dried whey powder. Animal Feed Science and Technology , 157(3-4), 159-167. DOI: https://doi.org/10.1016/j.anifeedsci.2010.03.005 Gaggia, F. et al. (2010). Probiotics and prebiotics in animal feeding for safe food production. International Journal of Food Microbiology , 141(6), 15-28. DOI: https://doi.org/10.1016/j.ijfoodmicro.2010.02.031 Cho, Y. I. and Yoon, K. J. (2014). An overview of calf diarrhea - infectious etiology, diagnosis, and intervention. Journal of Veterinary Science, 15(1), 1-17. DOI: https:// doi:10.4142/jvs.2014.15.1.1 Morrell, E. L. et al. (2008). Retrospective study of bovine neonatal mortality: Cases reported from INTA Balcarce. Argentina Revista Argentina de Microbiologia , 40(3), 151-157. DOI: https://www.redalyc.org/pdf/2130/213016785003.pdf Niggemman, B. (2006). Does unconventional medicine work through conventional modes of action. Journal of Allergy and Clinical Immunology , 118(3), 569-573. DOI: https://doi.org/10.1016/j.jaci.2006.06.021 Raabis, S. et al. (2019). Effects and immune responses of probiotic treatment in ruminants. Veterinary Immunology and Immunopathology , 208, 58-66. DOI: https://doi.org/10.1016/j.vetimm.2018.12.006 Rastall, R. and Maitin V. (2002). Prebiotics and synbiotics : towards the next generation. Current Opinion in Biotechnology , 5, 490-496. DOI: https://doi.org/10.1016/S0958-1669(02)00365-8 Renaud, D. L. et al. (2019). Evaluation of a multispecies probiotic as a supportive treatment for diarrhea in dairy calves: A randomized clinical trial. Journal of Dairy Science , 102(5), 4498-4505. DOI: https://doi.org/10.3168/jds.2018-15793 Sanei, M. et al. (2012). Effects of hormone or mineral–vitamin enriched colostrum on performance and weaning age of Holstein calves. Livestock Science , 149(1-2),190-194. DOI: https://doi.org/10.1016/j.livsci.2012.07.007 Soccol, C.R., et al. (2010). 'The Potential of Probiotics: A Review'. Food Technology and Biotechnology , 48(4), 413-434. DOI: https://hrcak.srce.hr/61713 Timmerman, H. M. et al. (2005). Health and growth of veal calves fed milk replacers with or without probiotics. Journal of Dairy Science , 88(6), 2154-2165. DOI: https://doi.org/10.3168/jds.S0022-0302(05)72891-5 Uyeno, Y. et al. (2015). Effect of Probiotics/Prebiotics on Cattle Health and Productivity. Microbes Environment . 30(2), 126-32. DOI: https://doi.org/10.1264/jsme2.ME14176 Veir, J. K. et al. (2007). Effect of supplementation with Enterococcus faecium (SF68) on immune functions in cats. Veterinary Therapeutics , 8(4) , 229-238. DOI: https://europepmc.org/article/med/18183541 Vrese, M. and Schvezenmeir, J. (2008). Probiotics, Prebiotics, and Symbiotics. Advances in Biochemical Engineering / Biotechnology , 111(1), 1-66. DOI: https://doi.org/10.1007/10_2008_097 Zhang, R. et al. (2016). Effect of oral administration of probiotics on growth performance, apparent nutrient digestibility and stress-related indicators in Holstein calves. Journal of Animal Physiology and Animal Nutrition , 100(1), 33-38. DOI: https://doi.org/10.1111/jpn.12338

Feeding Pasteurized Waste Milk to Preweaned Dairy Calves Changes Fecal and Upper Respiratory Tract Microbiota.

In the present study bacterial communities from both, the gastrointestinal and respiratory tract of pre-weaned dairy calves fed two different milk-feeding programs were characterized using 16S rRNA gene sequencing. Twenty female Holstein calves (38.8 ± 1.40 kg of BW) were fed pasteurized waste milk (pWM) containing residues of various antimicrobials. Twenty additional calves (38.1 ± 1.19 kg of BW) were fed milk replacer (MR) with similar nutrient composition (27.5% crude protein, 32.1% fat) compared to waste milk (28.6% crude protein, 30.0% fat) from day 1 to weaning at day 49 of study. Fecal samples and nasal swabs were collected on day 42 only from calves that were not treated with therapeutic antibiotics throughout the study, which were 8 MR and 10 pWM calves. To assess the impact of the two feeding regimes on the fecal and nasal microbiota, α and β-diversity measures were calculated, and the relative abundance of operational taxonomic units (OTUs) at different taxonomic levels was determined for each sample. In general, Chao1, PD Whole Tree, and Shannon diversity indices were similar for the fecal and nasal bacterial communities of calves regardless of the feeding regime. However, principal coordinate analysis based on unweighted Unifrac distances indicated differences in the structure of bacterial communities of calves fed milk replacer compared with those from calves fed pasteurized waste milk. The relative abundance of the Streptococcaceae family and the genus Histophilus was greater (P < 0.05) in the nasal microbiota of calves fed milk replacer than in those fed pasteurized waste milk. However, the genus Prevotella tended (P = 0.06) to be more relatively abundant in the respiratory tract of calves fed pasteurized waste milk than in those fed milk replacer. Differences in relative abundances of bacterial taxa in gut microbiota were only observed at the phylum level, suggesting that antimicrobial residues present in waste milk have a non-specific influence at a lower taxonomical level.

PRODUCTIVE PERFORMANCE OF BUFFALO CALVES FED DIFFERENT LEVELS OF MILK REPLACER

The objective of the present study was to evaluate the productive performance and economic efficiency for pre- and post-weaning buffalo calves fed milk replacer (MR) at levels of 9, 10 and 11% of their body weight in the 1st, 2nd and 3rd groups, respectively. Fifteen buffalo calves of average live body weight (LBW) 38.59±1.55 kg were chosen and separated from their dams within 2 h of birth. Calves were fed twice daily at the rate of 10% of their LBW on dam colostrum for the first three days and then the whole buffalo milk for seven days. Consecutively, calves were divided depending on their body weight into three groups with average body weight of 41.89±1.46 kg at the beginning of the experimental period (10 day initial age). The obtained results showed that increasing the level of milk replacer in the daily meal of suckling calves from 9% up to 11% of their body weight led to in parallel way to significant (P<0.05) decrease in solid feeds of starter, berseem hay (BH) and rice straw (RS). Calves in all experimental groups reached LBW over a range (87.35-94.56 kg) at weaning age (15 wk), being the heaviest was occurred with G3, while calves in G1 showed the lightest ones, being significant differences among dietary treatments. Total and daily gain from initial-18 wk were significant higher (P<0.05) in G2 than those of G1, but being similar with those found with G3. The digestibility of all nutrients as well as the feeding values (TDN and DCP) did not significantly different among the dietary treatments (different levels of MR). On the other hand, Values of PCV, Hb and RBCs were the highest (P<0.05), while WBCs was the lowest (P<0.05) in G2. Concentrations of IgG, IgM and IgA in blood serum were significant higher (P<0.05) with G2 than those of the other dietary treatments. Likewise, most blood metabolites were also markedly higher with G2 than those of G1 and G3 which have the low or high level of MR, respectively. Comparatively the values of liver enzymes and the concentration of thyroid hormones (T4) for low level-MR (G1) were mostly significant (P<0.001) higher than those of mid MR level (G2) and insignificant higher than those of the high MR level (G3). It could be concluded that, using milk replacer at 10% of their live body weight had the improved growth performances of suckling buffalo calves as well as recognized highest economic feed efficiency as compared to those reared on the same milk replacer at levels of 9 or 11%. This may help farmers to keep up and care of suckling buffalo calves and not sell it, and such regime could help to alleviate the problem of milk and beef shortage in Egypt.

Preweaned heifer management on US dairy operations: Part VI. Factors associated with average daily gain in preweaned dairy heifer calves

The study objective was to evaluate average daily gain (ADG) in dairy heifer calves based on health, feeding, management practices, and environmental factors. This study included 102 operations in 13 states that participated in the calf component of the National Animal Health Monitoring System's Dairy 2014 study. This 18-mo longitudinal study included 1,410 Holstein heifer calves monitored from birth to weaning. The mean ADG from birth to final weight was 0.74 kg/d. Backward elimination model selection in Proc Mixed after univariate screening determined factors that significantly affected ADG. The final model included dam lactation number, singleton versus twin birth, bedding type, Giardia and Cryptosporidium fecal shedding, disease events, a categorized average temperature-humidity index for the preweaning period (pTHI), amount of protein in the liquid diet (kg/d), milk pasteurization, direct-fed microbials, and the interaction between milk pasteurization and direct-fed microbials. After controlling for other independent variables in the model, calves born to first-lactation dams gained less (0.60 kg/d) than calves from second- (0.65 kg/d) or third- or greater-lactation (0.64 kg/d) dams. Singleton calves gained 0.07 kg/d more than twins. Calves bedded with sand or no bedding gained less (0.49 kg/d) than calves on all other bedding types. Calves negative for Cryptosporidium or Giardia at the time of sampling gained 0.03 or 0.02 kg/d more, respectively, than calves that were positive for Cryptosporidium or Giardia. Calves with no disease events gained 0.07 kg/d more than calves with one or more disease events. Calves experiencing an average pTHI <50 gained more (0.67 kg/d) than calves experiencing an average pTHI from 50 to 69 (0.62 kg/d), or ≥70 (0.59 kg/d). Within the range of observed kilograms of protein fed per day in the liquid diet, every additional 0.1 kg of protein fed per day equated to 0.02 kg/d of gain. Calves fed milk replacer with a direct-fed microbial gained less (0.44 kg/d) than calves fed milk replacer without a direct-fed microbial (0.60 kg/d) and calves fed pasteurized or unpasteurized milk regardless of direct-fed microbial use. These results highlight the importance of feeding a quantity and quality of a liquid diet to achieve optimal growth, keeping calves free of disease, the type or status of bedding, and mitigating the effects of temperature and humidity on preweaning ADG.

Short communication: The mammalian lignan enterolactone is absorbed by newborn dairy calves fed enterolactone-enriched milk

Flaxseed is the richest source of the plant lignan secoisolariciresinol diglucoside, which is converted to the mammalian lignans enterolactone (EL) and enterodiol by the gut microbiota of ruminants and humans. Enterolactone has been associated with improved animal and human health due to its antioxidant and anticarcinogenic properties. The objective of this study was to determine the pharmacokinetics of EL in newborn dairy calves fed milk replacer or EL-enriched milk. We hypothesized that newborn Holstein calves fed EL-enriched milk would have greater area under the curve and plasma concentration of EL compared with those fed milk replacer. On d 5 of life, calves were administered 2 L of milk replacer (n = 10; low-EL treatment: 123 nmol/L of EL) or 2 L of EL-enriched milk (n = 10; high-EL treatment: 481 nmol/L of EL) during the morning feeding (0700 h). Blood samples were taken from the jugular vein before (0 h) and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12, 24, and 48 h after oral administration of treatments. The area under the curve for the plasma concentration of EL was analyzed according to the trapezoidal rule between 0 and 12 h after treatment administration, and it was greater in high- (26 nmol/L × h) than low-EL calves (4.30 nmol/L × h). Similarly, the maximum concentration of EL in plasma was greater in high- (5.06 nmol/L) versus low-EL calves (1.95 nmol/L). Furthermore, the time after treatment intake to reach maximum plasma concentration of EL was faster in high- (4.31 h) compared with low-EL (4.44 h) treatment. Calves were able to absorb EL, indicating that EL-enriched milk can potentially be used as source of EL to pre-weaned ruminants.

Amino acid supplementation of calf milk replacers containing plasma protein

We determined the effects of calf milk replacers containing 0, 5, or 10% bovine plasma protein (PP), either without or with the supplemental amino acids (AA) Ile and Thr, on growth and health of male Holstein calves (n = 104) for 56 d. Milk replacers were formulated to contain 22% crude protein (CP), 20% fat, and 2.0% Lys. Milk replacers (12.5% solids) were fed at a rate of 1.5% of body weight (BW) on a dry matter basis during wk 1 and 1.75% of BW beginning on d 8. Starter was introduced on d 36 so that effects of PP and AA balance in milk replacers could be isolated. Intake, respiratory scores, and fecal scores were measured daily. Body weight and stature were measured weekly and blood serum samples were obtained during wk 4. Treatments had no effects on intakes of dry matter, CP, or metabolizable energy. During wk 6 and 8, BW was less as PP inclusion increased without AA supplementation compared with the other treatments. In wk 7, calves fed the higher level of PP without AA had lower BW than calves fed either the lower level of PP without supplemented AA or the higher inclusion of PP with supplemented AA. Average daily gain and gain:feed were lowest for calves fed the higher inclusion of PP without supplemented AA; heart girth in wk 7 was smallest for those calves. During the first 21 d, occurrence of scours was greater in calves fed the control milk replacer than in calves fed milk replacers containing the higher inclusion of PP either without or with supplemental AA. Occurrence of scours was also greater for the lower inclusion of PP compared with the higher inclusion of PP when AA were supplemented. Throughout the 56-d experiment, the chance of antibiotic treatment was greater for calves fed the control milk replacer than for all other treatments except the higher inclusion of PP without supplemental AA. Additionally, chance of antibiotic treatment was greater for the higher inclusion of PP without supplemental AA than for other milk replacers with PP. Calves fed treatments with the higher inclusion of PP had fewer days of scours than the controls. All milk replacers with PP, except the milk replacer containing higher PP without supplemental AA, had fewer days of treatment with antibiotics compared to the all-milk control. Inclusion of PP provided similar performance and improved health as long as milk replacers were balanced for Ile and Thr.