The aim of this study was to compare the effects of feeding pasteurized waste milk or saleable milk to calves on weight, health and emergence of antimicrobial resistance in Escherichia coli strains isolated from those calves. An experimental study under field conditions on a commercial pasture-based Argentinian dairy farm was carried out. Forty Holstein calves were assigned randomly to either pasteurized waste milk (PWM) or non-pasteurized saleable milk (SM). The antimicrobial agents (AM) used on the farm, both to treat or prevent diseases, were recorded. The passive immunity level, calf live weight, AM presence in milk, clinical examination of calves, and E. coli isolation and identification, were performed. A total of 258 E. coli strains were isolated from fecal samples (132 isolates from SM calves and 126 from PWM calves at six sampling times). All E. coli isolated were used to perform AM susceptibility tests (disc diffusion and agar dilution). No differences were observed between groups in health parameters, average daily gain or prevalence of resistant E. coli strains to any AM evaluated throughout the study. Peaks of trimethoprim, sulfamethoxazole and enrofloxacin minimum inhibitory concentration (MIC) were observed at 30 d in E. coli from both groups of calves, whilst additional peaks to tetracyclin and ampicillin were observed only in SM calves. All MIC apart from gentamicin decreased at 75 and 90 d of age (during the weaning period). Gentamicin MIC behaved differently, having no peaks and increasing at 90 d only in PWM group. In conclusion, we found no evidence that emergence of antibiotic resistance is related to the consumption of pasteurized waste milk.

Many studies on stress and pain rely, solely or mainly, on plasma Cortisol assessment. Confounding factors, such as handling, may cause a release of Cortisol making the interpretation of the results difficult. We looked at the influence of duration of restraint on the plasma cortisol levels of one-to-two month old calves. Forty-three calves were divided into four groups according to the interval between restraint and blood sampling: i) Group 0, immediate blood-sampling; ii) Group 0.5M, half a minute restraint; iii) Group IM, one minute restraint and iv) Group 2M, two minutes restraint. The only increase in plasma cortisol, compared with all the other groups, was seen with blood sampling after two minutes of restraint. This study provides evidence to suggest that cortisol released as a result of handling stress is not evident if blood sampling is carried out within one minute of restraining calves.

A series of measures of calf welfare was developed through a process of expert consultation. A welfare assessment of group-housed calves was carried out on 53 UK dairy farms during the winter of 2000/01. The assessment used animal-based measures including direct observation of the calves and examination of their health history through a review of farm records. The findings from this were compiled into a profile of calf welfare which outlined the range of results for each measure used. The results fell into the three categories of respiratory health, nutrition and general appearance. A broad range of results was found across the farms visited for the measures in each of these categories. Some farms performed well for all measures taken, and no farms performed consistently badly across all aspects of calf welfare. The majority of farms combined aspects of both good and poor welfare performance.

A common and painful management practice undertaken on most dairy farms is dehorning young calves (also called ‘disbudding’ when done on calves less than about two months of age). Despite much evidence the practice is painful, and effective means available to mitigate this pain, it is frequently performed without pain relief. The overall aim of this study was to describe different stakeholder views on the use of pain mitigation for disbudding and dehorning. Using an interactive, online platform, we asked participants whether or not they believed that calves should be disbudded and dehorned with pain relief and to provide reasons to support their choice. Participant composition was as follows: dairy producer or other farm worker (10%); veterinarian or other professional working with the dairy industry (7%); student, teacher or researcher (16%); animal advocate (9%); and no involvement with the dairy industry (57%). Of 354 participants, 90% thought pain relief should be provided when disbudding and dehorning. This support was consistent across all demographic categories suggesting the industry practice of disbudding and dehorning without pain control is not consistent with normative beliefs. The most common themes in participants’ comments were: pain intensity and duration, concerns about drug use, cost, ease and practicality and availability of alternatives. Some of the participants’ reasoning corresponded well with existing scientific evidence, but other reasons illustrated important misconceptions, indicating an urgent need for educational efforts targeted at dairy producers and dairy industry professionals advising these producers.

The study examined cattle farmers' and veterinarians' opinions of pain-induced distress associated with disbudding and attitudes towards non-steroidal anti-inflammatory drugs (NSAIDs). An emphasis was placed on investigating pain perception, veterinary-client communication and factors influencing analgesic use. Data were collected from an online questionnaire, links to which were published in professional periodicals, promoted by industry organisations and distributed on private practice mailing lists. A total of 110 veterinarians and 116 farmers who regularly disbud calves completed the questionnaires. Of the respondents, 56% of veterinarians and 14% of farmers routinely use NSAIDs for disbudding. Respondents perceived disbudding to be severely painful without medication and 82% of veterinarians and 43% of farmers perceived post-procedural pain to persist beyond 24 h. There was a significant difference between female and male veterinarians' pain scores for disbudding without medication. Veterinarians underestimate the influences of welfare and analgesic duration and effectiveness on farmers' decisions and overrated cost impact. The study highlights that improvements in veterinarian-farmer communication regarding calf disbudding analgesia are required; both in terms of refining veterinarians' understanding of farmers' priorities and guiding clients on methods to improve calf welfare.

The welfare of animals in transit may be affected by driving events, such as acceleration, braking and cornering. The relationships between driving events and the behavioural responses of the animals were examined. A single-deck, non-articulated vehicle was fitted with a video-recording system, GPS and tri-axial accelerometer. Two drivers each drove three standard journeys (two 3-h stages on different types of roads) for each animal type. Six different groups of five cattle (Bos taurus), ten calves and ten pigs (Sus scrofa) were each transported on separate journeys. Cattle stood still for most of each journey. Calves spent more time lying down during the second stage of the journey than during the first. Although pigs spent some of the time lying down, they spent more time sitting down and this time was greatest on a motorway and during the second stage of the journey. Frequent adjustments to maintain stability were required in response to acceleration, braking, cornering and rough road surfaces. Some animals experienced repeated falls. Falls occurred after a series of different types of events. The fewest losses of balance occurred on the motorway. As a motorway is a limited access multi-lane carriageway not crossed on the same level by other traffic lanes, the driver does not normally undertake frequent vehicular adjustments to respond to road features. Therefore, motorways give animals an opportunity to rest and avoid discomfort from repetitive driving events. If drivers anticipate potential driving events and prepare for them, it will reduce the likelihood and severity of losses of stability.

Although the relationship between farm animals and humans has strong implications for animal welfare and productivity, there have been few experimental studies on the influence of gentle interactions in group-housed calves. In the present study, Austrian Simmental calves were housed in groups of four under standard management conditions. Fourteen calves experienced 40 min of additional gentle interactions in the form of stroking and gentle talking during the first four weeks of life, whereas the remaining eleven calves did not. The animals’ fear of humans was measured by avoidance distance tests on 33 and 76 days of age and by an arena test that comprised three phases — isolation, presence of a human, isolation — at 34 days of age. The very low avoidance distances did not differ significantly between the groups. In the arena test, there was less behaviour indicative of stress in the presence of the experimenter compared with the isolation phases. Heart-rate measurements showed a corresponding pattern. Control calves showed more tail-flicking than stroked calves and had higher concentrations of salivary cortisol before and after the test. There were no other significant differences between the groups. The minor number of behavioural differences may result from the control animals’ good relationship with humans, ie there is a ceiling effect. If the general contact between stockpeople and calves is gentle and negative experiences are minimised, it is possible to achieve a good calf-human relationship without additional efforts.

Heat stress reduction in hutch-reared dairy calves is overlooked on most dairy farms. We hypothesised that during summer, the microclimate within hutches is directly affected by compass direction as a result of differences in exposure to solar radiation. On a bright, mid-August day a number of behavioural and physiological heat stress response measures (respiratory rate, body posture, being in the shade or sun) were recorded in 20-min intervals from 0720-1900h on calves housed in hutches with entrances facing all four points of the compass. In conjunction with this, dry bulb (ambient) and black globe temperatures, and wind speed were recorded both inside the plastic hutches and at one sunny site at the exterior. Data were compared in terms of distinct periods of the day (0720-1100, 1120-1500, 1520-1900h). Dry bulb temperatures were higher inside hutches compared to outside while for black globe temperatures the opposite was true. Daily average temperatures and respiratory rates did not differ between hutches facing different compass points. In the morning and afternoon, hutch temperature and calf respiratory rate differed relative to compass point. Calves in east- and north-facing hutches were seen more in the shade than those in south- and west-facing ones. Our conclusion was that in a continental region having hutch entrances face towards the east or north confers some advantages in mitigating severe solar heat load in summer.

Limited scientific literature is available for developing ‘best practice’ guidelines for the management of dairy goats (Capra hircus), particularly goat kids. Disbudding practices for kids and calves appear to be similar; however, it is important to recognise that kids are not small calves. Disbudding causes pain and is performed on calves and kids — welfare concerns surrounding disbudding affect both industries. In this review, we evaluate literature on disbudding of kids and calves and compare methodologies across the two species. In addition, we catalogue behavioural and physiological responses to disbudding and, finally, review alternatives to disbudding (or refinements). Although there may be certain similarities between the response of goat kids and calves to cautery disbudding, it is important to highlight the differences that do exist between the species to reduce the risk of potential detrimental effects (eg brain injury). Cautery disbudding is the most common and efficacious method of disbudding kids and calves; however, kids have thinner skulls and are disbudded at a younger age, which can increase the risk of thermal injury to the brain. Kids and calves show behavioural and physiological responses indicative of pain; however, variability in these responses between studies are likely due to differences in disbudding methodologies, study design and within-species variation. Effective pain mitigation strategies may differ across species; therefore, future research is needed to optimise pain mitigation strategies for kids. Currently, alternatives to cautery disbudding including: (i) selection for polled animals; (ii) managing horned animals; or (iii) the development of novel disbudding methods (eg cryosurgery, clove oil injection) have been deemed unsuitable by the industries as the methods are either impracticable or ineffective. Therefore, if disbudding is to continue, species-appropriate pain mitigation strategies need to be refined. Establishing best practice guidelines for disbudding kids requires managers to recognise that they are not small calves.

We investigated the effect of different types of mother-young contacts (fenceline, restricted and no contact) on the health, growth performance, behaviour and physiological state of Murrah buffalo calves. A total of 24 calves were allocated to three groups of 8: NCM (no calf–mother contact), RCM (restricted calf–mother contact) and FCM (fenceline calf–mother contact). At three months of age, the FCM calves had a higher average body weight (58.6 ± 1.5 kg) than the RCM (52.8 ± 1.3 kg) and NCM (53.6 ± 1.3 kg) calves (P < 0.05). The average daily gain (ADG) at three months of age was greater in FCM (0.6 ± 0.1 kg/d) than RCM (0.5 ± 0.1 kg/d) and NCM (0.5 ± 0.1 kg/d) calves (P < 0.05). The mean immunoglobulin G (IgG) concentrations were significantly greater on d 7, 28, 42 and d 56 of sampling (P < 0.05 for all comparisons) in FCM than RCM and NCM calves. The mean cortisol levels were highest in the NCM calves followed by RCM and the lowest values were observed in FCM calves on d 0, d 7, d 28, d 42 and d 56, respectively (P < 0.05, for all recorded days). The diarrhoea score and eggs per gram of faeces (EPG) were significantly greater in the NCM group compared to the RCM and FCM groups. The time spent in cross sucking, licking inanimate objects and self-licking was greatest (P < 0.05) in NCM calves, followed by RCM calves, and was almost non-existent in the FCM group on all the recorded weeks. Time spent in backward ear position was greater (P < 0.05) in FCM than RCM and NCM calves. The average time spent in forward ear position was greatest (P < 0.05) in the RCM calves followed by NCM with the lowest time observed in FCM calves. The mean duration of time spent by calves in the asymmetrical and axial ear position differed significantly (P < 0.05) among NCM, RCM and FCM calves, P < 0.05. The full and fenceline buffalo calf–mother contact system showed higher growth rates, lower levels of stress responses, oral stereotypies and eggs per gram of faeces. In addition, ear postures may be used as a dependable, and reliable measure of positive, low arousal emotional states.

This research paper aimed to evaluate the association between feeding waste milk to calves and the occurrence of antimicrobial multi-resistance by extended spectrum β-lactamase (ESBL) enzymes through determining their production by E. coli isolates from 32 dairy farms. Among β-lactamase enzymes, ESBL provide resistance to a wide variety of β-lactam antimicrobials including penicillin and 2nd, 3rd and 4th generation cephalosporins. Feeding waste milk to calves has been observed to lead to increased antimicrobial resistance in faecal isolates of calves. In each farm included in this study, faecal samples were collected from the rectum of five healthy calves in the first month of life and pooled into a single container. Five isolates from each pool were selected and confirmed to be E. coli by amplification of the 16S rRNA gene. ESBL production was confirmed phenotypically on 148 isolates from 31 farms by use of the double-disk synergy test. Genotypic confirmation of ESBL production was performed by PCR for the genes blaCTX-M-1, −2, −8, −9 and blaCMY-2. A questionnaire was also performed and a mixed logistic regression model was used to identify risk factors for the occurrence of antimicrobial resistance. A negative binomial regression model was also used, in order to assess whether there was any association between certain farm management practices and the number of ESBL-producing E. coli isolates from each farm. Phenotypic confirmation of ESBL production was obtained on 40 E. coli isolates from 15 farms (48.4%), whereas genotypic confirmation was obtained on 55 isolates from 20 farms (64.5%). The use of three or more different intramammary antimicrobials to treat mastitis within the previous year significantly impacted the number of ESBL-producing E. coli isolates; on farms that did so, there were more isolates in which ESBL-producing E. coli was present, when compared to farms that had used less formulations within the same time span.

To investigate the influences of cobalt (Co) and folic acid (FA) on growth performance and rumen fermentation, Holstein male calves (n 40) were randomly assigned to four groups according to their body weights. Cobalt sulphate at 0 or 0·11 mg Co/kg DM and FA at 0 or 7·2 mg/kg DM were used in a 2 × 2 factorial design. Average daily gain was elevated with FA or Co supplementation, but the elevation was greater for supplementing Co in diets without FA than with FA. Supplementing FA or Co increased DM intake and total-tract nutrient digestibility. Rumen pH was unaltered with FA but reduced with Co supplementation. Concentration of rumen total volatile fatty acids was elevated with FA or Co inclusion. Acetate percentage and acetate to propionate ratio were elevated with FA inclusion. Supplementing Co decreased acetate percentage and increased propionate percentage. Activities of xylanase and α-amylase and populations of total bacteria, fungi, protozoa, Ruminococcus albus, Fibrobacter succinogenes and Prevotella ruminicola increased with FA or Co inclusion. Activities of carboxymethyl-cellulase and pectinase increased with FA inclusion and population of methanogens decreased with Co addition. Blood folates increased and homocysteine decreased with FA inclusion. Blood glucose and vitamin B12 increased with Co addition. The data suggested that supplementing 0·11 mg Co/kg DM in diets containing 0·09 mg Co/kg DM increased growth performance and nutrient digestibility but had no improvement on the effects of FA addition in calves.

In 1991, USDA's National Animal Health Monitoring System (NAHMS) conducted its first dairy study, a baseline assessment that focused on the health and management of heifer calves. During the study, producers ranked respiratory disease among the top two most common health problems affecting dairy calves. Over the last 25 years, U.S. dairy producers have participated in six NAHMS studies, yielding a rich repository of information that has helped identify needs for research, extension, and education in the dairy industry. NAHMS’ most recent dairy study, conducted in 2014, provides the latest estimates on dairy cattle health and includes another in-depth look at heifer-calf health. While overall mortality in calves has decreased, bovine respiratory disease (BRD) remains an important cause of morbidity in calves. This raises the concern that BRD mitigation may be at a standstill on dairies. Research and on-farm experience have done much to elucidate the challenges associated with detection and perceived impacts of this complex disease. Continued development and implementation of new methods for monitoring health and detecting disease will provide additional tools to upend stalemating factors associated with BRD control, helping the dairy industry ‘turn a corner’ on this important disease.

In this Research Reflection we review management practices in small family farms with less than 100 cows. Small farms represent the majority of farms in the EU and the world, and they are of great importance for the economy of a country. On cattle farms, the welfare of calves is of primary importance for the profitability of the herd, and poor management is one of the main factors influencing calf health and survival. Data on the risk factors for calf welfare issues in small-scale farms are limited. For this purpose, the literature data from six world countries were presented and compared, including Serbia and Slovenia where a survey related to the issue was carried out within the COST Action FA1308, DairyCare. Some practices within the following areas in calf management were considered: calving management, care for new-born calves, use of painful procedures, colostrum management, cow–calf separation, calf feeding, weaning, calf housing, and general monitoring. In each of the countries, the health and welfare of calves are threatened by some omissions in rearing practices and the major are related to the new-born calf management, the feeding and watering management, and the application of hygienic measures. Many farmers are well aware of the importance of proper calf rearing; others would need more incentive to improve calf management. Each country should pay attention to the education of farmers about the most common deficiencies in calf management.

The hypothesis of the study was that feeding a relatively low amount of Se biofortified alfalfa hay during the dry period and early lactation would improve selenium status and glutathione peroxidase activity in dairy cows and their calves. Ten Jersey and 8 Holstein primiparous dairy cows were supplemented with Se biofortified (TRT; n = 9) or non-biofortified (CTR; n = 9) alfalfa hay at a rate of 1 kg/100 kg of BW mixed with the TMR from 40 d prior parturition to 2 weeks post-partum. Se concentration in whole blood, liver, milk, and colostrum, the transfer of Se to calves, and the glutathione peroxidase (GPx) activity were assessed. TRT had 2-fold larger (P < 0.05) Se in blood v. CTR that resulted in larger Se in liver and colostrum but not milk and larger GPx activity in plasma and erythrocytes but not in milk. Compared to CTR, calves from TRT had larger Se in blood but only a numerical (P = 0.09) larger GPx activity in plasma. A positive correlation was detected between Se in the blood and GPx activity in erythrocytes and plasma in cows. Our results demonstrated that feeding pregnant primiparous dairy cows with a relatively low amount of Se-biofortified alfalfa hay is an effective way to increase Se in the blood and liver, leading to greater antioxidant activity via GPx. The same treatment was effective in improving Se concentration in calves but had a modest effect on their GPx activity. Feeding Se biofortified hay increased Se concentration in colostrum but not in milk.

The coastal waters of east Lewis from the Butt of Lewis to Loch Erisort are a proposed Marine Protected Area (MPA) for Risso's dolphins (Grampus griseus). A total of 100.4 h (2006.4 km) of active search effort (Beaufort sea states ≤3) was collected during 72 dedicated boat surveys between 2010 and 2017 (primarily in August and September) in the southern part of the MPA and south to the Shiant Isles. Forty Risso's dolphin sightings and 24.1 h of encounter effort were recorded, predominantly along the southern and eastern Eye Peninsula in 20–40 m water depths and at distances <1 km from shore. Group size ranged from one to 50 animals (mean = 11.8 dolphins) and calves occurred in 37.5% of sightings. A total of 2404 shore-based scans (Beaufort sea states ≤3) carried out from Tiumpan Head between September 2011 and December 2017 resulted in 271 (11.3%) ‘dolphin-present’ scans. Dolphins were present year-round, with a seasonal increase between May and October. ‘Calf-present’ scans only occurred between April and October. Photo-identification images from 28 boat surveys produced a minimum population size of 117 animals. There was evidence of high inter- and intra-annual site fidelity, with individual dolphins photographically captured in up to six of the eight survey years, and between two and seven capture dates being recorded for over 45% of individuals within most years. The combined datasets support the importance of east Lewis for Risso's dolphins, and recommendations are made for ongoing monitoring of dolphin occurrence throughout the wider MPA.

The effect of transportation and lairage on the faecal shedding and post-slaughter contamination of carcasses with Escherichia coli O157 and O26 in young calves (4–7-day-old) was assessed in a cohort study at a regional calf-processing plant in the North Island of New Zealand, following 60 calves as cohorts from six dairy farms to slaughter. Multiple samples from each animal at pre-slaughter (recto-anal mucosal swab) and carcass at post-slaughter (sponge swab) were collected and screened using real-time PCR and culture isolation methods for the presence of E. coli O157 and O26 (Shiga toxin-producing E. coli (STEC) and non-STEC). Genotype analysis of E. coli O157 and O26 isolates provided little evidence of faecal–oral transmission of infection between calves during transportation and lairage. Increased cross-contamination of hides and carcasses with E. coli O157 and O26 between co-transported calves was confirmed at pre-hide removal and post-evisceration stages but not at pre-boning (at the end of dressing prior to chilling), indicating that good hygiene practices and application of an approved intervention effectively controlled carcass contamination. This study was the first of its kind to assess the impact of transportation and lairage on the faecal carriage and post-harvest contamination of carcasses with E. coli O157 and O26 in very young calves.

Performance of female Holstein calves (n = 60) were evaluated in three step-down milk feeding programmes: step-down 1 (STP1: 7.5 litres/day milk from days 1 to 21, 6 litres/day milk from days 22 to 42, 4 litres/day milk from days 43 to 63 and 2 litres/day milk from days 64 to 84 of the study); step-down 2 (STP2; 7.5 litres/day milk from days 1 to 21, 6 litres/day milk from days 22 to 42 and 2 litres/day milk from days 43 to 63 of the study); and step-down 3 (STP3; 7.5 litres/day milk from days 1 to 21, 4 litres/day milk from days 22 to 42 and 2 litres/day milk from days 43 to 63 of the study). Intakes of starter were monitored daily and body weight (BW), average daily gain (ADG) and wither height (WH) were measured monthly. Calves in STP3 had lower dry matter intake between 22 and 42 days than STP2 animals, but starter intake was greater in STP2 and STP3 calves than those in the STP1 treatment between 43–63 and 64–84 days. Total ADG was greater in STP2 and STP3 animals than in STP1 calves. No effect of treatment was observed on breeding age, BW, WH or service per conception. In addition, conception rate at first breeding was not influenced by treatment. It was concluded that the STP2 and STP3 milk feeding regimes improved performance in calves and there was no benefit in feeding milk for longer than 63 days in terms of breeding outcomes.

The prevalence and spatial distribution of Escherichia coli serogroups O26, O103, O111 and O145 in calves <7 days old in New Zealand and their relationship with serum IgG, weight and sex was determined by collecting recto-anal mucosal swabs (RAMS) (n = 299) and blood samples (n = 299) from two slaughter plants in the North Island. Real-time PCR of RAMS enrichment cultures revealed that 134/299 samples were positive for O26, 68/299 for O103 and 47/299 for O145, but none were positive for O111. Processing of positive enrichment cultures resulted in 49 O26, four O103 and five O145 isolates. Using multiplex PCR 25/49 (51%) O26 isolates were positive for stx1, eae, ehxA, 17/49 (34·7%) for eae, ehxA and 7/49 (14·2%) for eae only. All O103 and O145 isolates were positive for eae, ehxA only. O26 isolates were grouped into four clusters (>70% similarity) using pulsed field gel electrophoresis. Mapping of the farms showed the presence of farms positive for O26, O103 and O145 in three important dairy producing regions of the North Island. Calves positive for O103 were more likely to be positive for O26 and vice versa (P = 0·04). Similarly, calves positive for O145 were more likely to be positive for O103 and vice versa (P = 0·03). This study demonstrates that non-O157 E. coli serogroups of public health and economic importance containing clinically relevant virulence factors are present in calves in the North Island of New Zealand.

The importance of the use of exogenous butyrate in calves’ diets is due to its role as a factor stimulating the functional development of ruminal epithelium and improving calf performance during the transition from preruminant to ruminant status. Our review will first present results related to effects of the administration of butyrate in calves’ diets on the development of ruminal epithelium toward a more effective absorption and metabolism of fermentation products from the rumen. The introduction of sodium butyrate at a level of about 0.3% of diet dry matter is accompanied by an increase to 35% in butyrate concentration in the rumen of 33-day-old calves. Mutual reliance between an enhanced ruminal concentration of butyrate and the activities of transcription factors, genes and proteins involved in cell proliferation, ketogenesis and the maintenance of cell pH homeostasis in the ruminal epithelial cells has been clearly confirmed in many experiments. Second, the review presents results related to the effects of the introduction of butyrate salts in the diet on calf performance. Of 11 studies a positive effect was found in six; five of these were obtained from the calves that started receiving butyrate supplement at a level of about 0.3% diet dry matter from the age of 3 to 5 days. Results indicate that when a supplement is given to calves soon after birth the functional development of ruminal epithelium in cooperation with the endocrine and digestion systems is transferred into improving the efficiency of rearing. There have been no studies on the effects of greater amounts of butyrate salts in milk replacer; butyrate constitutes about 1.2% of the whole cow’s milk dry matter. In older calves, when butyrate administration is provided as a component of a starter concentrate at the increasing inclusion rate from 0.3% to 3.0%, the practical effect in calf performance relates to the risk of depression of rumen pH below 5.5 and accompanying disruption of the organization of the ruminal epithelial tissue. The higher risk is noted in calves received starter with substantial content of a rapidly degradable starch. At present, the insufficient number of positive results confirming the beneficial effect of butyrate supplements in terms of an improvement in performance does not allow their recommendation for use in the practical feeding of calves.