The behavior of dairy cattle in the transition period: Effects of blood calcium status.

The aim of this study was to use an automated behavior-monitoring system to objectively assess the association between lying and activity behavior in the precalving, calving, and postcalving periods between multiparous and primiparous cows with (1) normocalcemia, (2) subclinical hypocalcemia, or (3) clinical hypocalcemia at calving. Behavioral data and blood serum samples were collected from 51 multiparous and 21 primiparous Holstein dairy cattle. Blood samples from the coccygeal vein were taken within 24 h of calving, and serum was analyzed to measure total calcium concentration. Cows were classified into one of 3 categories: normocalcemia (serum calcium concentration ≥ 2.0 mmol/L), subclinical hypocalcemia (serum calcium concentration < 2.0 mmol/L, absence of clinical signs), and clinical hypocalcemia (clinical signs and successful treatment). An activity sensor was fitted to the right hind leg of cows 3 wk before their expected calving date. Data for lying time, standing time, number of steps, and the total number of standing and lying bouts (postural transitions) were automatically collected and summed into 15-min blocks. Behavioral variables were summarized into 2-h and 24-h periods before analyses. Mixed effect models were used to analyze cow behavior in the entire 14 d before calving (d -14 to -1), on the day of calving, and the entire 21 d postcalving (d 1 to 21). In the precalving period, multiparous cows with normocalcemia had fewer postural transitions (18.5 ± 6.9 no./d) compared with cows with subclinical hypocalcemia (23.5 ± 8.0 no./d) and clinical hypocalcemia (23.5 ± 8.6 no./d). However, there was no association between blood calcium status on lying time (min/d) or step count (no./d) for multiparous cows. For primiparous cows, the step count of cows with subclinical hypocalcemia remained constant across the period, and the step count of cows with normocalcemia decreased from 842.8 steps/d on d -14 to 427.5 steps/d on d -1. Postpartum cows with clinical hypocalcemia were less active (fewer steps) and spent 88 min/d (1.5 h) and 125 min/d (2.1 h) more time lying down compared with cows with subclinical hypocalcemia and normocalcemia, respectively. This shows that clinical hypocalcemia is associated with significant long-lasting behavioral effects on cows during the critical postpartum period.

Comparison of thermal imaging and rectal temperature in the diagnosis of pyrexia in pre-weaned calves using on farm conditions.

Measuring core body temperature is used as part of the diagnostic process in assessing the health of animals. Typically in calves, this is carried out using a rectal thermometer which can be time consuming, stressful to the calf and is invasive by nature. A non-invasive technique that is gaining recognition is thermal imaging. This study investigated the use of thermal imaging as a technique to assess core body temperature in pre-weaned artificially reared calves. A total of 125 male and female calves had rectal temperatures measured daily from day 7 until day 40 of life, and at the same time had a thermal image taken of the area around the medial canthus of the eye. A weak correlation (r = 0.28) was found between calf rectal temperature and thermal image temperature. A multivariable predictive model for core body temperature increased the correlation (r = 0.32) when including the environmental parameters of air temperature (p < .001) and wind speed (p < .001) as well as reconstituted milk replacer consumption (p < .01). The effectiveness of a predictive model including these parameters for the detection of calves with a core body temperature ≥ 39.5 °C was examined and found to have a sensitivity of 0% and a specificity of 100%. The results of this study demonstrate the need to take thermal environmental parameters into consideration when using thermal imaging to assess body temperature. However, the results suggest that accurate measures of core body temperature using thermal imaging cannot be achieved under commercial farm conditions. Further research is needed to determine what other factors could be measured to increase predictive ability.

The behavior of dairy cattle in late gestation: Effects of parity and dystocia.

The aim of this study was to objectively assess, using an automated behavioral monitoring system, any behavioral differences between primiparous and multiparous cows before calving, and to quantify any behavioral differences between assisted (dystocic) and unassisted (eutocic) calvings. Data were collected from 32 multiparous and 12 primiparous Holstein dairy cattle to describe normal calving behavior and parity differences. To quantify behavior related to calving difficulty, the data from 14 animals that had dystocia at calving were matched to cows that had an eutocic calving based on parity, locomotion score, calf breed, calf sex, month, and year of calving. An IceQube (IceRobotics Ltd., South Queensferry, United Kingdom) was fitted to the right hind leg of cows 4 wk before their expected calving date. Data for lying time, standing time, number of steps, motion index (total motion), and the total number of standing and lying bouts (postural transitions) were automatically collected and summed into 15-min blocks. Behavioral variables were summarized into 2-h periods and 24-h periods before analyses. Mixed-effect models were used to analyze cow behavior in the last 4 d before calving (d -4 to -1), and on the day of calving. In the 4 d before calving, compared with multiparous cows, primiparous cows lay down an average 2.8 h/d less, had 9.1 more postural transitions/d (37.7 ± 1.2 vs. 27.6 ± 0.7), walked 172 more steps/d, and had a higher motion index (2,673.2 vs. 1,981.5 units/d). There was an effect of 2-h period on all behavioral variables on the day of calving. No indicator of calving difficulty was found on the day of calving, nor the days leading up to calving. These findings suggest that parity should be considered when predicting the day of calving, and changes in cow behavior on the day of calving could be used to identify calving cows, and to predict the time of calving.

Risk factors associated with excessive negative energy balance in commercial United Kingdom dairy herds.

This study assessed risk factors associated with excessive negative energy balance (eNEB) in UK dairy cows between April 2006 and March 2015. Blood samples were analysed for ß-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA) and glucose. Following removal of all potential duplicate cows, a final dataset of 69,161 unique individual cows was obtained including biochemical results, individual cow and feed data. Generalised linear mixed-effect models and multivariable classification tree-based models showed that individual cow risk factors for eNEB included: (1) days relative to predicted calving date (dry cows); (2) days in milk (lactating cows); (3) body condition score (BCS; lactating cows ≥ BCS 4; OR 2.1); (4) milk yield (around 40 L per day); (5) parity (first lactation heifers; odds ratio [OR] 0.46 compared to older cows during lactation); and (6) chronic inflammatory conditions as assessed by globulin concentrations ≥ 50 g/L (OR 0.79 for cows with evidence of chronic inflammation). There was a higher prevalence during April to October (OR 1.19), and the lowest prevalence was in November. Feeding grass silage and wholecrop (silage made from cereal crops) to dry cows was associated with a reduced prevalence of eNEB, whereas access to grazed grass was associated with a higher prevalence in both the dry period (OR 1.32) and lactation (OR 1.33). Knowledge of the risk factors associated with eNEB in commercial dairy herds assists in both the implementation of herd monitoring programs and reduction of eNEB in dairy herds, with associated reductions in the risk of periparturient diseases and improved dairy cow performance.

Prevalence of excessive negative energy balance in commercial United Kingdom dairy herds.

The objectives of this study were to determine the individual animal and herd level prevalence of excessive negative energy balance (eNEB) in commercial UK dairy herds. Between April 2006 and March 2015, blood samples from 84,369 individual cows from 1748 different UK farms were received by a commercial laboratory service specializing in dairy cow nutritional monitoring. Following removal of all potential duplicate cows, the final dataset comprised 69,161 unique individual cows. The prevalence of eNEB was determined using plasma thresholds of ß-hydroxybutyrate (BHB), non-esterified fatty acids (NEFA) and glucose. Overall prevalence of subclinical ketosis (SCK) in the first 20 days of lactation was 28.5%, 17.3% and 11.7% using BHB thresholds of 1.0, 1.2 and 1.4 mmol/L respectively. Prevalence of NEFA values ≥0.5 mmol/L in the last 10 days prior to calving was 26.0%, and 40.3% of cows had NEFA values ≥0.7 mmol/L in the first 20 days in milk (DIM). Combining BHB, NEFA and glucose showed that 52.0% of cows had one or more of the three biochemical measures of energy balance outside the respective threshold value in the last 10 days pre-calving, and 75.2% of cows showed a similar biochemical pattern in the first 20 DIM. The median herd prevalence of elevated BHB and/or NEFA was 37.5% in late pregnancy and 59.8% in the first 20 DIM, with substantial herd variation. Using multiple measures for the assessment of energy balance, this study has shown that eNEB affects substantial numbers of UK dairy cows.

Molecular detection of Sarcocystis lutrae in the European badger (Meles meles) in Scotland.

Neck samples from 54 badgers and 32 tongue samples of the same badgers (Meles meles), collected in the Lothians and Borders regions of Scotland, were tested using polymerase chain reactions (PCRs) directed against the 18S ribosomal DNA and the internal transcribed spacer (ITS1) region of protozoan parasites of the family Sarcocystidae. Positive results were obtained from 36/54 (67%) neck and 24/32 (75%) tongue samples using an 18S rDNA PCR. A 468 base pair consensus sequence that was generated from the 18S rDNA PCR amplicons (KX229728) showed 100% identity to Sarcocystis lutrae. The ITS1 PCR results revealed that 12/20 (60%) neck and 10/20 (50%) tongue samples were positive for Sarcocystidae DNA. A 1074 bp consensus sequence was generated from the ITS1 PCR amplicons (KX431307) and showed 100% identity to S. lutrae. Multiple sequence alignments and phylogenetic analysis support the finding that the rDNA found in badgers is identical to that of S. lutrae. This parasite has not been previously reported in badgers or in the UK. Sarcocystis lutrae has previously only been detected in tongue, skeletal muscle and diaphragm samples of the Eurasian otter (Lutra lutra) in Norway and potentially in the Arctic fox (Vulpes lagopus).

Effect of yeast supplementation on performance, rumination time, and rumen pH of dairy cows in commercial farm environments.

The aims of the present study were to evaluate the effects of live yeast supplementation (Vistacell MUCL 39855, AB Vista, Marlborough, UK) on performance, rumination time, and rumen pH on dairy cows in commercial farm environments. Three trials were carried out, the trials lasted 12 (trial 1), 15 (trial 2), and 19 wk (trial 3). In each trial, 14 multiparous Holstein dairy cows were allocated to 2 groups that received (trial 1) a standard diet plus yeast, (trial 2) an acidogenic diet plus yeast, and (trial 3) grazing pasture plus yeast. Milk production, milk chemical characteristics, body weight and body condition score, rumination time, and rumen pH were monitored for each group throughout the 3 trials. No statistically significant differences were observed in any of the 3 trials for any of the recorded variables. In contrast, an effect of time (period or days in milk) on rumen pH was observed in all 3 of the trials, as time spent under the acidotic thresholds increased across the experimental periods; however the differences were not associated with live yeast supplementation. No effect of live yeast supplementation was observed in any of the 3 trials reported. Further research should include studies on animals at different stages of lactation (with emphasis on transition period and early lactation), consuming more challenging diets (higher level of inclusion of concentrates or starch), or under different environments such as grazing of succulent forages. Such studies might be required to elucidate any possible effect of live yeast supplementation of dairy cows when the rumen environment is under challenge.

Comparison of rumination activity measured using rumination collars against direct visual observations and analysis of video recordings of dairy cows in commercial farm environments.

Automated systems for monitoring the behavior of cows have become increasingly important for management routines and for monitoring health and welfare. In the past few decades, various devices that record rumination have been developed. The aim of the present study was to compare rumination activity measured with a commercially available rumination collar (RC) against that obtained by direct visual observations and analysis of video recordings in commercial dairy cows. Rumination time from video recordings was recorded by a trained observer. To assess observer reliability, data were recorded twice, and the duration of recorded behaviors was very similar and highly correlated between these 2 measurements (mean=39±4 and 38±4 min/2 h). Measurements of rumination time obtained with RC when compared with analysis of video recordings and direct observations were variable: RC output was significantly positively related to observed rumination activity when dealing with animals housed indoors (trial 1 video recordings: slope=1.02, 95% CI=0.92-1.12), and the limits of agreement method (LoA) showed differences (in min per 2-h block) to be within -26.92 lower and 24.27 upper limits. Trial 1 direct observations: slope=1.08, 95% CI=0.62-1.55, and the LoA showed differences to be within -28.54 lower and 21.98 upper limits. Trial 2: slope=0.93, 95% CI=0.64-1.23, and the LoA showed differences to be within -32.56 lower and 19.84 upper limits. However, the results were poor when cows were outside grazing grass (trial 3: slope=0.57, 95% CI=0.13-1.02, and the LoA showed differences to be within wider limits -51.16 lower and 53.02 upper). Our results suggest that RC can determine rumination activity and are an alternative to visual observations when animals are housed indoors. However, they are not an alternative to direct observations with grazing animals on pasture and its use is not advisable until further research and validation are carried out.

Stillbirth in dairy calves is influenced independently by dystocia and body shape.

The objectives of this study were to determine (1) if stillborn calves born following dystocia present with specific injuries/pathological changes compared to stillborns delivered without difficulty, and (2) whether such stillborns differ in conformation from dystocic calves that survive. Post-mortem examinations were carried out on 20 stillborns that were either unassisted (N) or were 'farm-staff'-assisted/normally presented (FN) at birth. Evidence of greater trauma and bruising was observed in the FN calves and parameters such as body length, birth-weight and thyroid:body weight were similar. In a second part of the study birth-weight, body length and height, girth length, body mass (BMI), and ponderal (PI) indices were assessed in 490 calves. Regardless of the severity of dystocia, stillborns had greater body lengths and lower BMIs and PIs than calves born alive (P<0.05), suggesting prenatal factors contribute to their post-natal survival. FN calves were heavier than N calves (P<0.05), and both FN and farm-staff-assisted/malpresented calves had lower PIs than N calves (P<0.05). The study found that criteria such as grossly visible carcass haemorrhage, bruising, and brain congestion were not reliable in terms of identifying calves that had experienced dystocia. Half of the stillborns had breathed indicating they were alive and possibly had experienced pain/distress at time of delivery. Body conformation was related to stillbirth independently of dystocia, a finding likely reflecting inadequate prenatal development.

The impact of dystocia on dairy calf health, welfare, performance and survival.

Up to one-third of dairy calves are born after dystocia and this is a major cause of calf mortality. This study investigated the neonatal physiology, survival, health and subsequent growth of dairy calves following dystocia and is the first longitudinal study to analyse multiple effects and to look beyond the perinatal period. A total of 455 live born Holstein calves (N: No assistance, n=360; FN: Farmer assistance but normally presented calf, n=82; FM: Farmer assistance of malpresented calf, n=13) were followed from birth to first service (heifers) or until leaving the farm (bulls). Compared to N calves, FN and FM animals had higher salivary cortisol concentrations at day 1 (P<0.001) and FN calves had lower passive immune transfer (P=0.03). Dystocia had no biologically significant impact on rectal temperature throughout the first 4 days (P>0.05). During the first 60 days, FM calves had a higher proportion of days with non-routine health treatments (P<0.05) and, by the time of weaning, mortality in FN and FM heifers was higher than in N calves (2.8×; P<0.01). However, in surviving calves, growth to first service was not affected by dystocia category (P>0.05). Calves which survive dystocia experience lower passive immunity transfer, higher mortality and higher indicators of physiological stress. Such calves have poorer welfare in the neonatal period and possibly beyond. Strategies need to be implemented to improve the subsequent health and welfare of such calves and to lower the incidence of dystocia.

Mortality, hepatopathy and liver copper concentrations in artificially reared Jersey calves before and after reductions in copper supplementation.

High winter mortality (28 per cent) in female Jersey calves (80 IU/l in healthy females aged 3-24 weeks, and correlated with serum aspartate transaminase (AST). Copper supplementation of total mixed rations during lactation was excessive (40-60 mg added Cu/kg DM) and reduced to 16-28 mg Cu/kg, but supplementation of milk replacer and creep feed (10 and 35 mg added Cu/kg DM, respectively) continued. The syndrome recurred two years later, and liver Cu remained high in casualties (13.6 ± 2.6) and culled cows (6.38 ± 2.38 mmol/kg DM) prompting withdrawal of all Cu supplements. Mortality remained low (6-9 per cent) thereafter. Three years after removal of all Cu supplements, six culled newborn were examined postmortem; five had normal liver Cu (4.5 ± 1.73), but a sixth had 11.65 mmol/kg DM. In live, healthy calves (1-6 months old) sampled at the same time, GLDH and AST increased with age to levels found five years earlier, indicating possible subclinical hepatopathy. Causative links between Cu supplementation, high calf mortality and hepatopathy are plausible, and reductions in Cu supplementation may prove beneficial in other dairy herds.

Short communication: survival, growth to weaning, and subsequent fertility of live-born dairy heifers after a difficult birth.

The experience of a difficult birth (dystocia) is traumatic and has adverse effects on the newborn in various species. Despite affecting up to 1 in 3 births in dairy cattle, studies on calves have been mostly limited to the first day of life. The objective of this study was to investigate the effects of dystocia on the survival to calving, growth to weaning, and subsequent fertility as nulliparous animals. Historical data from live-born Holstein heifer calves born from cows with various birth difficulty scores (no assistance; moderate; high difficulty) were obtained from 2 herds (Edinburgh herd: n=1,237; Crichton Royal Farm herd: n=721). Each herd was analyzed separately for birth weights, weaning weights, growth rate to weaning, number of services to conception, and age at first calving using REML and generalized linear mixed model analyses. Survival analysis (Cox proportional hazards model) was used in the Edinburgh herd to analyze the subsequent survival of live-born heifers, whereas descriptive data are presented for the Crichton Royal Farm herd. A higher mortality risk to weaning and to first service was observed in the live-born heifers that experienced moderate difficulty at birth compared with heifers born naturally. Surviving dystocial heifers had similar growth-to-weaning and fertility performance as heifers born naturally in both herds. It could be that the performance of dystocial heifers that survived to weaning was not affected or that it was compensated for by farm management. This study highlights long-term effects of the early experience of a difficult birth and thereby stresses the importance of preventing dystocia not just from the point of view of the adult cow, but also from the perspective of the calf. This would also improve farm efficiency and calf welfare.

Teladorsagia circumcincta resistance to moxidectin and multiple anthelmintic groups in ewes following use of the persistent drug before lambing.

This paper describes the nematode control strategy adopted by a Scottish hill sheep farmer. It provides an example of the limited use of anthelmintic drugs, targeted towards control of the periparturient rise in faecal nematode egg output in ewes and exploitation of grazing management, resulting in limited exposure of naive sheep to infective larvae on pasture. Resistance to benzimidazole, imidazothiazole and macrocyclic lactone anthelmintics, and to a combination of a macrocyclic lactone and imidazothiazole anthelmintic drugs was diagnosed. The targeted use of a persistent anthelmintic drug to control a periparturient rise in faecal nematode egg output in ewes may be unnecessary and selects strongly for resistance when the reservoir of anthelmintic-susceptible nematodes in refugia is small at the time of treatment. However, the use of a persistent anthelmintic drug in a selective proportion of ewes can be important and probably does not select strongly for resistance when the reservoir of anthelmintic-susceptible nematodes in refugia is large at the time of treatment. The former circumstances might arise on many Scottish hill sheep farms, whereas the latter may occur on upland and lowground farms, depending on previous grazing management, anthelmintic use and winter weather conditions. These factors must be taken into account when preparing sustainable health plans for nematode parasite control in individual sheep flocks.

Melatonin treatment prior to the normal breeding season increases fetal number in United Kingdom sheep flocks.

Litter size determined ultrasonographically at 45-90 days after mating in eight groups of commercial sheep (n=2609) treated with slow release melatonin implants immediately prior to the natural breeding season showed a 19% treatment effect averaged over the eight groups, from 148% to 167% (P<0.01) compared with controls (n=2499). Control groups had a litter size ranging from 124% to 194% thereby representing most commercial production systems in the UK sheep industry. This is the first large scale study of slow release melatonin implants in commercial UK flocks to demonstrate a significant positive effect on litter size when used before the natural breeding season. The data indicate that increased productivity and profitability could be achieved while maintaining desirable purebred characteristics.

Use of metabolic profiles for the assessment of dietary adequacy in UK dairy herds.

Between April 1999 and March 2004, metabolic profile analyses were performed on individual blood samples from 35,506 dairy cattle in the UK. Assessment of the cows' energy status by the analysis of plasma samples for beta-hydroxybutyrate, glucose and non-esterified fatty acids showed that 70.4 per cent of the cows in early lactation (10 to 20 days calved), 57.1 per cent of the cows in mid-lactation (51 to 120 days calved) and 57.7 per cent of the dry cows within 10 days of their predicted calving date had one or more energy metabolites outside the optimum range; in addition, 16 per cent of the cows in early lactation, 5.6 per cent of those in mid-lactation and 20.5 per cent of the dry cows within 10 days of their predicted calving date had a low plasma urea nitrogen concentration, indicating poor intakes of effective rumen-degradable protein. Abnormalities in the concentrations of magnesium, inorganic phosphate, copper, selenium and iodine were relatively uncommon. The transitional period, particularly in late pregnancy, was commonly identified as a constraint on productivity. Nutritional problems were most commonly associated with poor feed intakes and poor feed management, rather than with the formulation of the rations.

Cloning and expression of the extra-cellular part of the alpha chain of the equine high-affinity IgE receptor and its use in the detection of IgE.

The high-affinity receptor for IgE (FcepsilonRI) plays a central role in IgE-mediated allergic reactions. Cross-linking of FcepsilonRI by IgE-antigen complexes results in the activation of mast cells and basophils and is thought to contribute to the immunopathology of Heaves, a chronic obstructive pulmonary disease of horses. Recombinant protein corresponding to the extra-cellular portion of the FcepsilonRI alpha subunit, cloned and sequenced previously, was expressed using both mammalian cells and insect cells. The yield of expressed protein was considerably greater using insect cells and the baculovirus expression system. The recombinant proteins differed in size between the two systems, presumably due to differences in the extent of glycosylation. However, recombinant protein from both cell systems bound equine IgE present in bronchoalveolar lavage fluid from horses with Heaves. These results suggest that the recombinant extra-cellular part of FcepsilonRI should be a useful tool with which to study equine IgE responses.