A multisite, randomized field trial to evaluate the influence of lactoferrin on the morbidity and mortality of dairy calves with diarrhea

Condition of surplus dairy calves during marketing: A cross-sectional study

In North America, surplus dairy calves are sold soon after birth and often marketed through a third party (e.g., live auction, livestock dealer) before entering veal or dairy beef production. Previous work has demonstrated that a percentage of calves have failed transfer of passive immunity (FTPI) and clinical signs of disease on arrival at calf-raising facilities, but little is known regarding calf condition during marketing. The objectives of this cross-sectional study were to (1) estimate the prevalence of FTPI and poor health outcomes in surplus calves on arrival at livestock dealers, and (2) investigate the association between calf-level variables (body weight, sex, source) and health outcomes. Two livestock dealers in Ohio were visited 2 to 3 times per week, with approximately 28 calves enrolled in the study per visit for a total of 1,119 calves. One blood sample per calf was obtained to evaluate FTPI by measuring serum total protein concentrations (using a cutoff <5.1 g/dL). Calves were clinically evaluated for signs of arthritis, broken ribs or tail, dehydration, depression, diarrhea, fever, navel inflammation, and respiratory disease by 2 observers; health outcomes were dichotomized using clinically relevant cut points. Descriptive statistics were used to estimate the prevalence of calves with poor health outcomes. Multivariable logistic regression models were built to investigate the effect of body weight, sex, and source on health outcomes. Nineteen percent (206/1,091) of calves had FTPI.

Preliminary exploration of the health and behavior around the time of transportation of beef × dairy calves and Holstein bull calves 3 days of age or younger in the western United States

In the western United States, it is common practice for dairy and beef × dairy calves to be sold and shipped within the first few days of life, making transportation one of the first challenges that a calf will experience. To date, no published research has examined the effects of calf transport within the western United States. The objectives of this observational study were to describe the health status of calves leaving the source dairy, characterize transportation conditions and calf behavior during transportation, and determine if age at transportation and transportation duration are associated with dehydration, blood glucose and lactate, and behavior. An observational study was performed on 2 source dairies in the western United States. Initial enrollment consisted of dairy bull calves and beef × dairy calves (n = 126 total) across 16 transport cohorts which were sold and transported to separate calf-raising facilities approximately 80 km from the source dairy. Health exams and measurements were performed on all study participants 2 to 3 h before transport and ≤2 h after transport. Two researchers performed health exams using the Wisconsin calf health score, which included clinical respiratory scores, lung ultrasound, and fecal, navel, and joint scores. Hydration status was assessed using skin tent duration. Blood samples were collected and immediately analyzed for blood glucose and lactate using glucose and lactate meters. Accelerometers were attached at the source dairy on ≤10 calves in each of the 16 transport groups to record movement and behavior during transport (n = 90 had accelerometers attached). Results showed that about half of calves (49%) were identified with at least one health abnormality before transport. Researchers found an association between age and dehydration status in which calves <24 h of age were more likely to be dehydrated compared with calves 1 d of age. Additionally over half of the calves (56%) were identified as dehydrated after transport. To the authors' knowledge, this is the first observational study that investigates the effects of transportation on dairy bull and beef × dairy calf health and welfare in the western United States. Our findings support the need for improved management and decision making before transporting calves to reduce the negative effects of transport.

Rehydration post-transport: duration of oral fluid therapy on behavior, biochemical measures of hydration, and health of neonatal dairy calves

The objective of this study was to determine the impact of 0, 1, 2, or 3 d of oral electrolyte solutions (OES) following transport on calf behavior, biochemical measures of hydration, and subsequent health. Two cohorts of 60 Holstein bull calves ~3 to 7 d of age were included in this experiment. Calves (n = 30/treatment) were randomized to 1 of 4 treatments on arrival at a calf-raising facility: (1) 1-d OES, (2) 2-d OES, (3) 3-d OES, or (4) no OES (control). Calves were evaluated for signs of arthritis, depression, dehydration, diarrhea, fever, navel inflammation, and respiratory disease on arrival (day 0) and 1, 2, 3, and 7 d after arrival. Blood was obtained following each examination to assess biochemical measures of hydration, including serum electrolytes, glucose, hematocrit, lactate, pH, and serum total protein (STP). Calves were fitted with 3D accelerometers attached to the right hind leg along the metatarsus bone to continuously measure lying time. Linear regression models with Gaussian or Poisson link functions were used to test differences between treatments in blood parameters, as well as disease frequency and behavior, respectively. Calves spent the most time lying immediately post-transport (day 0); however, there was no effect of OES treatment on lying time. On arrival, 90% (95% CI: 84.6% to 95.4%) of calves had mild to moderate dehydration, and there was no significant difference in hydration status across treatments. Mildly dehydrated calves that received 1- and 2-d OES had higher STP concentration compared to the control. Moderately dehydrated calves that received 3- vs. 1-d OES had higher (101.4 vs. 93.7 mmol/L, respectively; P = 0.01) glucose concentration, and 3- vs. 2-d OES (101.4 vs. 96.2, respectively; P = 0.07) calves tended to have higher glucose concentration. The prevalence of failed transfer of passive immunity (STP < 5.1 g/dL) and hypoglycemia (glucose < 4.95 mmol/L) was 26.7% (18.6% to 34.7%) and 76.5% (68.7% to 84.2%), respectively. The frequency of moderate dehydration was lower for calves that received 2-d OES compared to the control (count ratio: 0.4; 0.2% to 0.8%; P = 0.009). These results underline the need for more research on rehydration strategies to help inform calf processing protocols. Future research should investigate preconditioning strategies to minimize the impact of marketing and transport on dairy calves. Continued nutritional-based research is also needed to better support calves' recovery post-transport.

Effects of two strains of Lactobacillus isolated from the feces of calves after fecal microbiota transplantation on growth performance, immune capacity, and intestinal barrier function of weaned calves

Introduction

Weaning stress seriously affects the welfare of calves and causes huge economic losses to the cattle breeding industry. Probiotics play an important role in improving animal growth performance, enhancing immune function, and improving gut microbiota. The newly isolated strains of Lactobacillus reuteri L81 and Lactobacillus johnsonii L29 have shown potential as probiotics. Here, we studied the probiotic properties of these two strains on weaned calves.

Methods

Forty calves were randomly assigned to four groups before weaning, with 10 calves in each group, control group (Ctrl group), L. reuteri L81 supplementation group (2 g per day per calf), L. johnsonii L29 supplementation group (2 g per day per calf), L. reuteri L81 and L. johnsonii L29 composite group (2 g per day per calf), and the effects of Lactobacillus reuteri L81 and Lactobacillus johnsonii L29 supplementation on growth performance, immune status, antioxidant capacity, and intestinal barrier function of weaned calves were evaluated.

Results

The results showed that probiotics supplementation increased the average daily weight gain of calves after weaning, reduced weaning diarrhea index (p < 0.05), and increased serum IgA, IgM, and IgG levels (p < 0.05). L. reuteri L81 supplementation significantly decreased IL-6, increased IL-10 and superoxide dismutase (SOD) levels at 21 d after weaning (p < 0.05). Moreover, probiotics supplementation significantly decreased serum endotoxin (ET), diamine oxidase (DAO), and D-lactic acid (D-LA) levels at different time points (p < 0.05). In addition, supplementation with L. reuteri L81 significantly reduced the crypt depth and increased the ratio of villus height to crypt depth (p < 0.05) in the ileum, increased gene expression of tight junction protein ZO-1, Claudin-1 and Occludin in jejunum and ileum mucosa, reduced the gene expression of INF- γ in ileum mucosa and IL-8 in jejunum mucosa, and increased the abundance of beneficial bacteria, including Bifidobacterium, Lactobacillus, Oscillospira, etc.

Discussion

verall, these results showed that the two strains isolated from cattle feces after low concentration fecal microbiota transplantation improved the growth performance, immune performance, antioxidant capacity, and intestinal barrier function of weaned calves, indicating their potential as supplements to alleviate weaning diarrhea in calves.

Condition of bob veal calves on arrival at an abattoir in Ohio

Previous research has shown surplus dairy calves arrive at 'formula-fed' veal operations in North America in sub-optimal condition; however, little is known about the condition of 'bob' veal calves on arrival at abattoirs. The objectives of this study were to assess the condition of bob veal calves on arrival at an abattoir in Ohio and determine risk factors for poor health outcomes. On arrival, 35 calves in each of 12 cohorts (n = 420 calves) were assessed using a standardised health examination. A blood sample was also collected to assess failed transfer of passive immunity (FTPI) and hypoglycaemia. Descriptive statistics were used to describe the prevalence of poor health outcomes. Mixed-effects logistic regression models were used to identify if calf breed, sex, or source were risk factors for poor health outcomes. The most common physical health concern observed on arrival at the abattoir was dehydration (mean: 68.6%), followed by thin body condition (39.8%), and navel inflammation (25.7%). Approximately one-quarter (23.4%) of calves had FTPI and 73.4% were hypoglycaemic. Male calves were more likely than females to arrive hypoglycaemic. Hydration status was associated with breed; Jersey and crossbreed calves were less likely to be dehydrated than Holstein-Friesian calves. Buying station tended to be associated with FTPI. These results underline the need for more studies investigating morbidity, mortality, and their underlying risk factors to promote calf welfare prior to slaughter in each stage of the production chain: on the dairy farm of birth, during marketing, and in transit.

Effects of fecal microbiota transplantation from yaks on weaning diarrhea, fecal microbiota composition, microbial network structure and functional pathways in Chinese Holstein calves

This study was conducted to investigate the effect of fecal microbiota transplantation (FMT) from yaks on weaning diarrhea, fecal microbiota composition, microbial network structure and functional pathways in Chinese Holstein Calves. In this study, 50 calves were randomly divided into five groups of 10 each: NC group (no supplementation), Control group (normal saline), low concentration FMT group (LFMT, 1 × 108 CFU/ml), high concentration FMT group (HMFT, 1 × 109 CFU/ml), and sterilized FMT group (SMFT, sterilized bacterial solution). The test lasted for 30 days. We found that FMT reduced the incidence of diarrhea in weaned calves, and the anti-diarrhea effect of LFMT was stronger than those of HFMT and SFMT. Calf feces were collected by rectal palpation on days 5, 10, 15, and 20 post-weaning, and high-throughput sequencing of bacterial 16S rRNA and fungal internal transcribed spacer region of fecal microbiota was performed. We observed that the richness and diversity of bacterial microbiota in the LFMT, HFMT, and SFMT groups were higher than those in the NC and Control groups at day 20 after weaning. The treatment had a significant effect on bacterial richness (p &lt; 0.05), but not on fungal diversity or richness. The analysis of gut microbiome showed that Firmicutes and Bacteroides were the main bacterial phyla in the feces of weaned calves, and norank_ f Muribaculaceae, UCG-005, Rikenellaceae_RC9_gut_group, Bacteroides, and Blautia were the main genera. Ascomycota and Basidiomycota were the main fungal phyla. Compared to abundance parameters in the Control and NC groups, relative abundances of Firmicutes in the FMT groups increased at different time points after weaning. The relative abundance of Blautia and Lactobacillus in the LFMT group increased significantly after weaning. In addition, abundances of Ruminococcus and Romboutsia, which produce short-chain fatty acids, were also increased in different FMT groups. FMT significantly increased the relative abundance of beneficial bacteria, enhanced the complexity of the fecal microbial network, and promoted important metabolic and cellular processes in weaned calves. In conclusion, our study provides a reference and theoretical basis for FMT to prevent calf weaning diarrhea and other intestinal diseases in ruminants.

Supplementation with galacto-oligosaccharides in early life persistently facilitates the microbial colonization of the rumen and promotes growth of preweaning Holstein dairy calves

We aimed to determine the effects of dietary supplementation with galacto-oligosaccharides (GOS) on the growth performance, serum parameters, and the rumen microbial colonization and fermentation of pre-weaning dairy calves. The study comprised 2 phases of 28 and 42 d, respectively. During phase 1, 24 newborn female Holstein dairy calves were randomly allocated to consume a diet supplemented with 10 g/d GOS (GOS, n = 12) or not (CON, n = 12). Thereafter, during phase 2, the GOS group was further divided into 2 groups: one that continued to consume GOS (GOSC, n = 6) and one that no longer consumed GOS (GOSS, n = 6), alongside the CON group. Galacto-oligosaccharides increased the average daily gain (ADG), body weight, feed efficiency, and serum high-density lipoprotein-cholesterol concentration of dairy calves during phase 1 (P < 0.05). Supplementation with GOS for the entire study reduced the incidence of diarrhea and increased the serum total protein and Ca concentrations (P < 0.05) compared with the CON group. The effect of GOS supplementation persisted after it was stopped because the ADG and final body weight of the GOSS group were higher than those of the CON group (P < 0.05). Furthermore, the GOSS group showed a persistently lower incidence of diarrhea and greater colonization of the rumen with probiotics, at the expense of less beneficial bacteria, which would promote ruminal fermentation and microbial protein synthesis. These findings provide a theoretical basis for the rational application of prebiotics and have important practical implications for the design of early life dietary interventions in dairy calf rearing.

Longitudinal Study of Fecal Microbiota in Calves with or without Diarrhea Episodes before Weaning

Simple Summary

Animal production is searching for ways to reduce antimicrobial use, and the best way is to avoid their use by maintaining the health of the animals. The microbiota is involved in the host health, and when the fecal microbiota was analyzed in calves that developed or not diarrhea, differences linked to the health status were detected. While changes in the fecal microbiota were observed with time (during the first 2 months of age) in all the calves, the microbiota from the healthy animals presented an earlier stabilization and some changes in low abundant bacteria, which may play a role in the subsequent health status of the animals. Bacteria classified in the families Coriobacteriaceae and Phyllobacteriaceae, and the bacterium Epulopiscium were found in the core of the microbiota of the healthy calves (calves that did not have diarrhea) possibly with a protective probiotic effect. On the other hand, several bacteria, such as Lachnospira, Neisseria and Solibacillus, were found only in the core of the microbiota obtained from calves that had diarrhea, indicating that they could be linked to a higher predisposition to suffer diarrhea. These results can help in the development of new probiotics to promote gut health in calves.

Abstract

The microbiota plays an important role in the development of diarrhea in pre-weaned calves. The characterization of the fecal microbiota in health and disease can be critical to unravel the bacterial dynamics associated with diarrhea and help with its prevention and control. In this study, we aimed to detect changes in the fecal microbiota of calves that experienced early-life diarrhea episodes. Fecal samples were taken from calves remaining healthy and calves with an episode of diarrhea during the study. We sampled at arrival (12 days of age) and after one and two months of life; also, at the time of the diarrhea episode for the diarrheic calves (day 17). Samples were processed to extract total DNA, submitted to 16S rRNA gene sequencing, and bioinformatically analyzed to infer the bacterial populations. Microbiota changes through time were reported for both groups. However, we detected an earlier stabilization in the healthy group. Moreover, we detected changes within low abundant taxa that may play a role in the subsequent health status of the animals. The fecal microbiota of healthy and diarrheic calves showed different dynamics in the diversity through time that may be the reflections of the variations within low-abundant taxa.

Effects of Anemoside B4 on Diarrhea Incidence, Serum Indices, and Fecal Microbial of Suckling Calves

The study was conducted to evaluate the effects of Anemoside B4 on diarrhea incidence, serum indices, and fecal microbial of suckling calves. Sixty newborn Chinese Holstein calves with similar body weight (43.7 ± 3.9 kg) were randomly divided into four groups with 15 calves each, fed the diet which was supplied 0 (CON), 15 (A1), 30 (A2), and 45 (A3) mg/day of Anemoside B4, respectively. The trial period is 56 days. The blood and fecal samples were collected at 28 and 56 days of age. Results show that during the whole trial period, the diarrhea incidence in Group A1, A2, and A3 was significantly lower than that in Group CON (p < 0.05). Compared with the Group CON, Anemoside B4 supplementation significantly decreased the contents of serum D-lactic acid and diamine oxidase at 28-day-old (p < 0.05). At 56-day-old, the content of serum D-lactic acid in Group A3 tended to be higher (0.05 < p < 0.01), and the content of serum diamine oxidase in Group A3 increased significantly, in comparison with Group CON (p < 0.05). Group A3 increased the level of Chao1 and Simpson indices at 28-day-old (0.05 < p < 0.01), and Chao1, Observed_species, Shannon, and Simpson indices at 56-day-old (p < 0.05), in comparison to Group CON. Compared with Group CON, 45 mg / day Anemoside B4 supplementation significantly increased the contents of Bacteroidota (at the phylum level), Prevotella (at the genus level) at 28-day-old (p < 0.05), and the content of Sutterella (at the genus level) at 56-day-old (p < 0.05), promoted the processes of energy metabolism, glycan biosynthesis and metabolism, metabolism of cofactors and vitamins (p < 0.05). A positive correlation was observed between Prevotella and metabolism of cofactors and vitamins, energy metabolism, and glycan biosynthesis and metabolism. A positive correlation was observed between Sutterella and energy metabolism. In conclusion, Anemoside B4 could effectively alleviate calf diarrhea, protect the integrity of intestinal mucosa, and change the structure of intestinal microbiota, indicating the potential value of Anemoside B4 in regulating intestinal microbiota and the prevention of intestinal diseases.

Bacterial Causes of Intestinal Disease in Dairy Calves: Acceptable Control Measures

Although diarrhea in dairy calves is common, it is not always due to bacteria. Escherichia coli, Salmonella, and Clostridium perfringens are the most commonly implicated bacteria, but an etiologic diagnosis should be sought before specific treatment is instituted. Nonspecific treatment such as fluid, electrolyte, and nutritional support should be accomplished while diagnostics are pending. Antimicrobials should not be a first-line therapy for calf diarrhea. Control measures are discussed.

Combined supplementation of sodium humate and glutamine reduced diarrhea incidence of weaned calves by intestinal microbiota and metabolites changes

This study was conducted to investigate the effects of combined supplementation of sodium humate (HNa) and glutamine (Gln) on growth performance, diarrhea incidence, serum parameters, intestinal microbiome, and metabolites of weaned calves. In Exp. 1, 40 calves were randomly assigned to four treatments: 1) NC (negative control, basal diet), 2) 1% H+1% G (basal diet extra orally gavaged with 1 g of HNa and 1 g of Gln daily), 3) 3% H+1% G (basal diet extra orally gavaged with 3 g of HNa and 1 g of Gln daily), and 4) 5% H+1% G (basal diet extra orally gavaged with 5 g of HNa and 1 g of Gln daily). The HNa and Gln were together mixed with 100 mL of milk replacer (51 to 58 d of age) or water (59 to 72 d of age) and orally administrated to each calf from a bottle before morning feeding. In a 21-d trial, calves on the 5% HNa+1% Gln group had higher (P < 0.05) average daily gain (ADG) and lower (P < 0.05) diarrhea incidence than those in the control group. In Exp. 2, 20 calves were randomly assigned to two treatments fed with a basal diet and a basal diet supplemented with 100 mL of 5% HNa+1% Gln. In a 21-d trial, calves supplemented with HNa and Gln had higher (P < 0.05) ADG, IgG concentration and glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) activities in the serum, but lower (P < 0.05) diarrhea incidence, as well as serum diamine oxidase (DAO), D-isomer of lactic acid (D-lac), tumor necrosis factor-α (TNF-α), and malondialdehyde (MDA) concentrations compared with control group. Results of intestinal microbiota indicated that supplementation with HNa and Gln significantly increased (P < 0.05) the abundance of intestinal beneficial microbiota. Moreover, supplementation with HNa and Gln altered 18 metabolites and enriched 6 Kyoto Encyclopedia of Genes and Genomes pathways in weaned calves. In conclusion, combined supplementation with HNa and Gln could decrease diarrhea incidence of weaned calves via altering intestinal microbial ecology and metabolism profile.

Prevalence and predictors of bacteremia in dairy calves with diarrhea

Gastrointestinal disease is the most common cause of mortality in dairy calves. Septicemia is an important sequela of diarrhea, and the possibility of bacteremia is the primary justification for empirical antimicrobial therapy. Prior reports estimate that approximately one-third of diarrheic calves are bacteremic; however, those estimates may not be representative of routine cases in heifer calves on commercial dairy operations early in the course of disease. We hypothesized that the prevalence of bacteremia in calves with diarrhea and systemic signs of illness is less than prior estimates (~31%), and that clinical signs or hematological values would be associated with the presence or absence of bacteremia. Female calves less than 21 d of age with and without diarrhea were enrolled from 2 commercial dairy farms over a 10-wk period. Diarrheic calves were enrolled if they were newly diagnosed, had loose to watery stool, had either dehydration (assessed by skin tent and eye position) or depression (assessed by suckle reflex and standing ability), and had no prior antimicrobial treatments. Complete health assessments were conducted at 0, 7, and 14 d following enrollment. An aseptic jugular venous sample was collected and cultured using aerobic and anaerobic methods, and bacterial species were identified using mass spectrometry. Poisson regression models were used to identify associations with bacteremia and compute adjusted prevalence ratios. The prevalence of bacteremia in diarrheic and healthy calves was 9.26% (10/108, 95% confidence interval: 4.5-16%) and 14.8% (4/27, 95% confidence interval: 1.4-28.2%), respectively. Among calves with diarrhea, those with a fever (>39.7°C) or depression were 4.8 and 6.5 times more likely, respectively, to have bacteremia. Only 1 of 47 calves (2%) without signs of depression was bacteremic. The prevalence of bacteremia in diarrheic calves with signs of systemic illness (depression or dehydration) was significantly lower than previous estimates, and bacteremia was rare among calves without observed depression. Antimicrobial therapy targeting bacteremia is not currently justified in routine cases of diarrhea in preweaning calves without signs of depression. These results suggest a substantial opportunity for more targeted antimicrobial therapy to improve antimicrobial stewardship.

Effects of sodium humate and glutamine combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned calves

This experiment was conducted to investigate the effects of sodium humate (HNa) and glutamine (Gln) alone or combined supplementation on growth performance, diarrhea incidence, blood parameters, and intestinal microflora of weaned Holstein calves. In a 14-day experiment, 40 calves at 51 ± 3 days of age were randomly allocated to four treatment groups: (1) NC (basal diet), (2) NC + 5% HNa, (3) NC + 1% Gln, and (4) NC + 5% HNa + 1% Gln. Calves combined supplementation with HNa and Gln had a higher (P < .05) ADG, serum concentration of glucose (GLU), IgA, and IgG but lower fecal scores, diarrhea incidence, serum concentration of TNF-α, and IL-10 compared with NC group (P < .05). Compared with NC group, HNa + Gln group showed higher (P < .05) serum GSH and T-AOC activities but lower (P < .05) concentration of MDA and D-lac. Furthermore, the abundances of Prevotella ruminicola, Bifidobacterium, and Lactobacillus in rectal digesta were increased (P < .05), but the Escherichia coli was significantly decreased. In conclusion, combined supplementation with HNa and Gln can effectively improve the immune status, antioxidant capacity, and intestinal microflora of the weaned calves while reducing diarrhea incidence.

Longitudinal health outcomes for enteric pathogens in preweaned calves on Ohio dairy farms

Calf gastrointestinal disease remains one of the main causes of productivity and economic losses on dairy operations. The majority of pre-weaned calf mortality is attributed to diarrhea or other digestive problems. Five enteric pathogens are commonly associated with diarrhea in dairy calves, including bovine rotavirus, bovine coronavirus, Escherichia coli, Salmonella spp., and Cryptosporidium parvum. Pathogen-associated differences in health outcomes and case fatality rates have not been well-characterized. Additionally, updated prevalence estimates may reflect important changes in the epidemiology of the pathogens on dairy farms. For this cohort study, fecal samples were collected from 276 clinically ill calves across 5 central Ohio dairy farms on the first day of diarrheal diagnosis. Genomic techniques, including reverse transcription polymerase chain reaction (RT-PCR) and droplet digital polymerase chain reaction (ddPCR) were used to test for the presence of the five enteric pathogens. A Poisson regression model was used to estimate the relative risk of mortality, and a survival analysis with a Cox regression model was used to analyze time to return to a healthy clinical status by pathogen. Rotavirus was the most frequently identified at 68.1 % (188/276), followed by F5 (K99)⁺E. coli at 42.5 % (114/268), C. parvum at 28.4 % (66/232), coronavirus at 5.8 % (16/276), and Salmonella had the lowest prevalence at 3.7 % (10/268). Risk of mortality tended to be higher for calves infected with Salmonella (RR = 3.83; 95 %CI: 0.93, 16.02, p = 0.062); however, the time to return to a healthy clinical status was not different for different pathogens. Only farm was a significant predictor of time to return to health (p = 0.017); the within-farm median duration of signs substantially varied between 2 and 7 days. The results suggest that the prevalence and distribution of rotaviral infections is higher than reported in prior studies. With the exception of infections caused by Salmonella spp., pathogen diagnosis on the first day of diarrhea was a poor predictor of the outcome and duration of disease. These results are critical to guide the implementation of prevention measures to detect, treat, and prevent calf diarrhea.

Extended transition milk feeding for 3 weeks improves growth performance and reduces the susceptibility to diarrhea in newborn female Holstein calves

Dairy calves may benefit from extending the duration of feeding transition milk (TM; the subsequent two to six milkings after parturition) to enhance performance and health during early life. The objective of this study was to assess the effect of replacing pasteurized waste milk (non-saleable milk containing antibiotic and/or drug residues) with pasteurized TM for 3 weeks on the growth performance and health of dairy calves. A total of 84 healthy newborn female Holstein calves were blocked by birth order and assigned randomly to 4 treatment groups with partial replacement of pasteurized waste milk by TM (second milkings after parturition) at 0 (0 l/day TM + 6 l/day milk), 0.5 (0.5 l/day TM + 5.5 l/day milk), 1 (1 l/day TM + 5 l/day milk), or 2 l (2 l/day TM + 4 l/day milk) for a 21-day period. From day 22 onward, all calves were fed individually with 6 l/day pasteurized waste milk. Calves were weaned on day 60 and monitored until day 90 of the study. Liquid feed DM intake (DMI) was increased with increasing levels of TM (P = 0.001). Starter feed DMI and total DMI (liquid feed DMI + starter feed DMI) were not affected by the treatment effect. Calves were fed 2 l/day TM gained more BW compared with those in the control group during the postweaning and overall periods. The average daily gain tended (P = 0.06) to be higher in calves fed 2 l/day TM compared with calves fed 0 (+ 65 g/day), 0.5 (+ 53 g/day), or 1 (+ 76 g/day) l/day TM during the preweaning period. Daily weight gain was also higher in calves fed 2 l/day TM compared with calves in the control group during the postweaning (+ 137 g/day; P = 0.04) and overall (+89 g/day; P < 0.01) periods, respectively. Calves fed 2 l/day TM had a higher feed efficiency compared with calves in the control group during all studied periods. The calves fed TM2 had a lower chance of having diarrhea compared with other treatment groups. Duration but not the frequency of diarrhea was lower in calves fed TM2 vs TM0 (2.5 vs 4.2days; P = 0.03). In general, partial replacement of waste milk with TM (2 l/day) may be recommended to feed dairy calves at an early stage of life to support a higher growth rate and health benefits.

Effect of the Source of Zinc on the Tissue Accumulation of Zinc and Jejunal Mucosal Zinc Transporter Expression in Holstein Dairy Calves

Simple Summary

Diarrhea is the main cause of death in newborn calves and is associated with antibiotic use and economic loss for dairy farms. In this study, we evaluated the effects of different sources of the mineral zinc (zinc oxide (ZnO) and zinc methionine (Zn-Met)) on the growth, incidence of diarrhea, tissue zinc accumulation, gene expression of jejunal zinc transporters and serum concentrations of zinc-dependent proteins in newborn Holstein dairy calves. We found that Zn-Met supplementation promoted growth and reduced diarrhea from the second week after birth. It also increased the levels of zinc in the serum and liver, the level of the transporter protein ZIP4 in the jejunal mucosa, as well as the serum alkaline phosphatase and metallothionein concentrations compared to the control group. ZnO supplementation had similar but less marked effects to Zn-Met supplementation. These results suggest that Zn-Met supplementation may be an alternative to antibiotics for the treatment of newborn calf diarrhea.

Abstract

Zinc is considered to be an anti-diarrheal agent, and it may therefore reduce the incidence of diarrhea in young calves. In the present study, we aimed to compare the effect of zinc source on growth performance, the incidence of diarrhea, tissue zinc accumulation, the expression of zinc transporters, and the serum concentrations of zinc-dependent proteins in neonatal Holstein dairy calves. Eighteen male newborn Holstein dairy calves were fed milk and starter diet supplemented with or without 80 mg zinc/d in the form of Zn-Met or ZnO for 14 days, and were then euthanized. Zn-Met supplementation improved average daily gain and feed efficiency, and reduced the incidence of diarrhea, compared with control calves (p < 0.05). It also increased the serum and hepatic zinc concentrations and the mRNA expression of the ZIP4 transporter in the jejunal mucosa of the calves (p < 0.05). In addition, the serum alkaline phosphatase activity and metallothionein concentration were higher in Zn-Met-treated calves than in control calves (p < 0.05). ZnO supplementation had similar effects, but these did not reach significance. Thus, Zn-Met supplementation is an effective means of increasing tissue zinc accumulation and jejunal zinc absorption, and can be used as an anti-diarrheal strategy in neonatal calves.

Extended colostrum feeding for 2 weeks improves growth performance and reduces the susceptibility to diarrhea and pneumonia in neonatal Holstein dairy calves

The objective of this study was to determine the effect of partial replacement of whole milk with colostrum on the growth performance and health status of Holstein dairy calves. Neonatal heifer calves (n = 144; 2 d of age; 39.3 ± 0.82 kg of body weight, BW; mean ± SE) were assigned randomly to 3 groups with partial replacement of pasteurized whole milk with pasteurized colostrum at 0 (C0; 0 kg/d of colostrum + 5 kg/d of whole milk), 350 g (C350; 0.350 kg/d of colostrum + 4.650 kg/d of whole milk), or 700 g (C700; 0.700 kg/d of colostrum + 4.300 kg/d of whole milk) for 14 d; there were no refusals of liquid feed. From d 15 onward, the calves were fed with 5 kg/d of pasteurized whole milk, weaned on d 61, and monitored until d 81 of life. Throughout the study, the calves had free access to fresh clean water and calf starter. Partial replacement of whole milk with colostrum increased liquid feed dry matter intake (DMI) but decreased milk DMI; however, intakes of starter DMI, total DMI, metabolizable energy, crude protein, and ether extract were not affected by treatments. Overall, the C700 calves recorded greater weaning weight, final BW, heart girth change, feed efficiency, and average daily gain (ADG). The calves fed milk had a higher chance of having rectal temperature ≥39.4°C and general appearance score ≥2 compared with those receiving colostrum in their milk. Diarrhea was more prevalent in C0 versus C700 calves. The occurrence of pneumonia tended to be higher in milk-fed calves compared with C350 and C700 animals. Colostrum feeding resulted in fewer days with a rectal temperature ≥39.4°C, general appearance ≥2, diarrhea, and pneumonia. We computed Cliff's delta (effect sizes) of the extended colostrum feeding (C350 vs. C0, C700 vs. C0, and C700 vs. C350) on starter and milk DMI, ADG, BW, and feed efficiency. In C350 calves, the effect sizes (Cliff's delta) for milk DMI, ADG, BW, and feed efficiency were positive and small, but negative in C700 calves. Compared with C350 treatment, C700 treatment resulted in greater final BW with moderate effect size. Positive and moderate effects of feeding colostrum (C700 vs. C0) were observed on postweaning ADG and final BW. The findings showed that the inclusion of 700 g of colostrum in 5 kg of milk may be beneficial to the growth and health of dairy calves.