Short communication: Immunoglobulin variation in quarter-milked colostrum

Whereas whole first-milked colostrum IgG1 variation is documented, the IgG1 difference between the quarter mammary glands of dairy animals is unknown. First colostrum was quarter-collected from healthy udders of 8 multiparous dairy cows, all within 3h of parturition. Weight of colostrum produced by individual quarters was determined and a sample of each was frozen for subsequent analysis. Immunoglobulin G1 concentration (mg/mL) was measured by ELISA and total mass (g) was calculated. Standard addition method was used to overcome colostrum matrix effects and validate the standard ELISA measures. Analysis of the data showed that cow and quarter (cow) were significantly different in both concentration and total mass per quarter. Analysis of the mean IgG1 concentration of the front and rear quarters showed that this was not different, but the large variation in individual quarters confounds the analysis. This quarter difference finding indicates that each mammary gland develops a different capacity to accumulate precolostrum IgG1, whereas the circulating hormone concentrations that induce colostrogenesis reach the 4 glands similarly. This finding also shows that the variation in quarter colostrum production is a contributor to the vast variation in first milking colostrum IgG1 content. Finally, the data suggests other factors, such as locally acting autocrine or paracrine, epigenetic, or stochasticity, in gene regulation mechanisms may impinge on colostrogenesis capacity.

Hyperketonemia during lipopolysaccharide-induced mastitis affects systemic and local intramammary metabolism in dairy cows

Hyperketonemia interferes with the metabolic regulation in dairy cows. It is assumed that metabolic and endocrine changes during hyperketonemia also affect metabolic adaptations during inflammatory processes. We therefore studied systemic and local intramammary effects of elevated plasma β-hydroxybutyrate (BHBA) before and during the response to an intramammary lipopolysaccharide (LPS) challenge. Thirteen dairy cows received intravenously either a Na-DL-β-OH-butyrate infusion (n = 5) to achieve a constant plasma BHBA concentration (1.7 ± 0.1 mmol/L), with adjustments of the infusion rates made based on immediate measurements of plasma BHBA every 15 min, or an infusion with a 0.9% NaCl solution (control; n = 8) for 56 h. Infusions started at 0900 h on d 1 and continued until 1700 h 2 d later. Two udder quarters were challenged with 200 μg of Escherichia coli LPS and 2 udder quarters were treated with 0.9% saline solution as control quarters at 48 h after the start of infusion. Blood samples were taken at 1 wk and 2h before the start of infusions as reference samples and hourly during the infusion. Mammary gland biopsies were taken 1 wk before, and 48 and 56 h (8h after LPS challenge) after the start of infusions. The mRNA abundance of key factors related to BHBA and fatty acid metabolism, and glucose transporters was determined in mammary tissue biopsies. Blood samples were analyzed for plasma glucose, BHBA, nonesterified fatty acid, urea, insulin, glucagon, and cortisol concentrations. Differences were not different for effects of BHBA infusion on the mRNA abundance of any of the measured target genes in the mammary gland before LPS challenge. Intramammary LPS challenge increased plasma glucose, cortisol, glucagon, and insulin concentrations in both groups but increases in plasma glucose and glucagon concentration were less pronounced in the Na-DL-β-OH-butyrate infusion group than in controls. In response to LPS challenge, plasma BHBA concentration decreased in controls and decreased also slightly in the BHBA-infused animals because the BHBA concentration could not be fully maintained despite a rapid increase in BHBA infusion rate. The change in mRNA abundance of citrate synthase in LPS quarters was significant between the 2 treatment groups. The results indicate that elevated circulating BHBA concentration inhibits gluconeogenesis before and during immune response to LPS challenge, likely because BHBA can replace glucose as an energy source.

Induced hyperketonemia affects the mammary immune response during lipopolysaccharide challenge in dairy cows

Metabolic adaptations during negative energy and nutrient balance in dairy cows are thought to cause impaired immune function and hence increased risk of infectious diseases, including mastitis. Characteristic adaptations mostly occurring in early lactation are an elevation of plasma ketone bodies and free fatty acids (nonesterified fatty acids, NEFA) and diminished glucose concentration. The aim of this study was to investigate effects of elevated plasma β-hydroxybutyrate (BHBA) at simultaneously even or positive energy balance and thus normal plasma NEFA and glucose on factors related to the immune system in liver and mammary gland of dairy cows. In addition, we investigated the effect of elevated plasma BHBA and intramammary lipopolysaccharide (LPS) challenge on the mammary immune response. Thirteen dairy cows were infused either with BHBA (HyperB, n=5) to induce hyperketonemia (1.7 mmol/L) or with a 0.9% saline solution (NaCl, n=8) for 56 h. Two udder quarters were injected with 200 μg of LPS after 48 h of infusion. Rectal temperature (RT) and somatic cell counts (SCC) were measured before, at 48 h after the start of infusions, and hourly during the LPS challenge. The mRNA abundance of factors related to the immune system was measured in hepatic and mammary tissue biopsies 1 wk before and 48 h after the start of the infusion, and additionally in mammary tissue at 56 h of infusion (8h after LPS administration). At 48 h of infusion in HyperB, the mRNA abundance of serum amyloid A (SAA) in the mammary gland was increased and that of haptoglobin (Hp) tended to be increased. Rectal temperature, SCC, and mRNA abundance of candidate genes in the liver were not affected by the BHBA infusion until 48 h. During the following LPS challenge, RT and SCC increased in both groups. However, SCC increased less in HyperB than in NaCl. Quarters infused with LPS showed a more pronounced increase of mRNA abundance of IL-8 and IL-10 in HyperB than in NaCl. The results demonstrate that an increase of plasma BHBA upregulates acute phase proteins in the mammary gland. In response to intramammary LPS challenge, elevated BHBA diminishes the influx of leukocytes from blood into milk, perhaps by via modified cytokine synthesis. Results indicate that increased ketone body plasma concentrations may play a crucial role in the higher mastitis susceptibility in early lactation.

The energy expenditure of 2 Holstein cow strains in an organic grazing system

Until recently, measurements of energy expenditure (EE; herein defined as heat production) in respiration chambers did not account for the extra energy requirements of grazing dairy cows on pasture. As energy is first limiting in most pasture-based milk production systems, its efficient use is important. Therefore, the aim of the present study was to compare EE, which can be affected by differences in body weight (BW), body composition, grazing behavior, physical activity, and milk production level, in 2 Holstein cow strains. Twelve Swiss Holstein-Friesian (HCH; 616 kg of BW) and 12 New Zealand Holstein-Friesian (HNZ; 570 kg of BW) cows in the third stage of lactation were paired according to their stage of lactation and kept in a rotational, full-time grazing system without concentrate supplementation. After adaption, the daily milk yield, grass intake using the alkane double-indicator technique, nutrient digestibility, physical activity, and grazing behavior recorded by an automatic jaw movement recorder were investigated over 7d. Using the (13)C bicarbonate dilution technique in combination with an automatic blood sampling system, EE based on measured carbon dioxide production was determined in 1 cow pair per day between 0800 to 1400 h. The HCH were heavier and had a lower body condition score compared with HNZ, but the difference in BW was smaller compared with former studies. Milk production, grass intake, and nutrient digestibility did not differ between the 2 cow strains, but HCH grazed for a longer time during the 6-h measurement period and performed more grazing mastication compared with the HNZ. No difference was found between the 2 cow strains with regard to EE (291 ± 15.6 kJ) per kilogram of metabolic BW, mainly due to a high between-animal variation in EE. As efficiency and energy use are important in sustainable, pasture-based, organic milk production systems, the determining factors for EE, such as methodology, genetics, physical activity, grazing behavior, and pasture quality, should be investigated and quantified in more detail in future studies.

Peripartal progesterone and prolactin have little effect on the rapid transport of immunoglobulin G into colostrum of dairy cows

Colostrum formation and lactogenesis in the mammary gland and the timing of parturition are regulated by endocrine signals. Changes in progesterone (P4) and prolactin (PRL) are considered key events that inhibit colostrum formation, trigger parturition, and signal the onset of lactation. The goal of our study was to determine if colostrum yield and composition and immunoglobulin transfer are affected by prepartum milking relative to the decrease in P4, peak of PRL, or occurrence of parturition. Twenty-three multiparous cows were randomly assigned to 1 of 2 groups: (1) control with first milking at 4h postcalving (CON, n=11), and (2) treatment group with first milking approximately 1d before calving and second milking at 4h after parturition (APM, n=12). Colostrum yields were recorded and proportional samples were analyzed for immunoglobulin G (IgG) concentration. Blood plasma samples for the analyses of P4 and PRL were collected 3 times daily at 8-h intervals for 4d prepartum and again taken at 4h after parturition. Total colostrum mass of APM cows was higher than that of CON cows. Immunoglobulin G concentration and protein content did not differ between antepartum milking in APM cows and postpartum milking in CON cows. Colostrum IgG concentration and protein content in APM cows at the postpartum milking were lower compared with the IgG concentration established at the prepartum (APM) and postpartum milkings of CON cows. Immunoglobulin G mass did not differ in first and second colostrum collection in APM cows but was lower compared with that of CON cows. The sum of IgG mass in APM cows (prepartum + postpartum collections) did not differ from that of CON cows. Lactose and fat in milk (concentration and mass) increased from first to second milking in APM cows. Total mass of lactose and fat in APM cows (prepartum + postpartum collections) was greater compared with that of CON cows. The finding that the time of milking relative to parturition, P4 decrease, and PRL peak slightly affected yield and quality of colostrum emphasizes the complex interactions of numerous endocrine and morphological changes occurring during colostrogenesis and lactogenesis in dairy cows. The considerably rapid transfer of immunoglobulins into colostrum of prepartum-milked cows within a few hours leads to the hypothesis that the transfer of IgG can be very fast and-contrary to earlier findings-persist at least until parturition.

Short communication: Timing of first milking affects serotonin (5-HT) concentrations

Hormonal signals differentially regulate the timing of parturition, as well lactogenesis and, potentially, colostrum formation in the mammary gland. Non-neuronal serotonin (5-HT) is a homeostatic regulator of the mammary gland. In the current study, we manipulated the timing of first milking to investigate its effects on serum 5-HT and calcium concentrations in the maternal and calf circulation, as well as in colostrum. Twenty-three cows were randomly assigned to a control (CON; n=10) group, milked for the first time at 4h postcalving, or a treatment (TRT; n=13) group, milked for the first time approximately 1 d before calving in addition to 4h postcalving. Maternal blood samples were collected for 4 d precalving, 3 times daily, and 1 blood sample was taken 4h postcalving. Calf blood samples were collected 4 (before first colostrum feeding) and 12h after birth, and at 3 wk of age. Calves from both treatments were fed colostrum from their respective mothers. Serum 5-HT concentrations were greater in CON cows and decreased significantly in TRT cows after milking was initiated precalving (951 vs. 524 ± 111 ng/mL, respectively). Cow serum calcium concentrations were affected by time, beginning to decrease 1 d precalving until 4h postcalving, but this drop in serum calcium was more pronounced in TRT cows. Serum 5-HT and calcium concentrations were negatively correlated (r=-0.57) for the CON cows and positively correlated (r=0.6) for the TRT cows. Maternal calcium and 5-HT decreased similarly due to precalving milking. Calcium and 5-HT concentrations were greater in colostrum collected from TRT cows milked precalving. Overall, calves had higher circulating 5-HT concentrations than cows, and calves born to TRT cows had increased 5-HT concentrations compared with the CON. Precalving milking could affect 5-HT synthesis within the mammary gland and therefore affect maternal 5-HT and calcium concentrations. Further research is needed in ruminants to assess the extent of 5-HT placental transfer, its role on pre- and postnatal development of the calf, the importance of its presence in colostrum, and potential long-term effects on calf health

Milk production during the colostral period is not related to the later lactational performance in dairy cows

In dairy cows, milk yield increases rapidly after parturition until a peak at around wk 6 of lactation. However, the description of the shape of the lactation curve is commonly based on weekly average milk yields. For a more detailed analysis of the milk production curve from the very beginning of lactation including the colostral period and the effect of colostrum yield on further lactational performance, the first 10 milkings after parturition, daily milk yields from d 1 to 28 of lactation, and the cumulative milk production on d 100 to 305 of lactation were investigated in 17 primiparous and 39 multiparous cows milked twice daily. Milk yield at the first milking after parturition (colostrum) ranged from 1.3 to 20.7kg (Δ=19.4kg) in multiparous and from 1.8 to 10.9kg in primiparous animals (Δ=9.1kg). At the tenth milking, milk production ranged from 9.2 to 21.5kg (Δ=12.3kg) in multiparous and from 7.0 to 15.2kg (Δ=8.2kg) in primiparous animals. Immediately after parturition, daily milk production increased rapidly, but after approximately 1wk in lactation, the slope of the daily milk production curve flattened and continued more linear. A nonlinear regression equation was used to determine this timely change, which occurred earlier in primiparous (d 6.9±0.3) than in multiparous cows (d 8.2±0.2). The correlation between the amount of first colostrum and milk production during further lactation decreased already from 0.47 on d 5 to 0.32 on d 14. In multiparous cows, the correlation between total milk production of the previous 305d standard lactation and the amount of first colostrum was not significant (correlation=0.29), whereas the correlation with the daily production increased from 0.45 on d 5 to 0.69 on d 14. However, in primiparous animals, correlations between first-colostrum yield and daily milk yields up to d 28 of lactation were not significant, possibly due to the smaller sample size compared with multiparous animals. First-colostrum yield and cumulative milk production of 100, 200, and 305 lactation days were not significantly correlated in multiparous and primiparous cows. In conclusion, the milk production during the first few milkings is widely independent from the overall production level of a cow. Potentially, genetic selection toward lower milk yield during the very first days after parturition at a simultaneously high lactational performance may be a tool to ensure sufficient colostrum quality and to reduce the metabolic load around parturition.

Short communication: Circulating and milk adiponectin change differently during energy deficiency at different stages of lactation in dairy cows

Adiponectin, one of the most abundant adipokines in circulation, is known for its role in regulation of body metabolism. The aim of this study was to evaluate the effects of a negative energy balance (NEB) at 2 stages of lactation (lactational NEB at the onset of lactation and an induced NEB by feed restriction near 100 d of lactation) on circulating adiponectin concentrations. We also investigated the effect of feed restriction on adiponectin concentrations in milk and the relationships of blood and milk adiponectin with selected plasma or milk variables and with measures of body condition. Plasma adiponectin was measured in 50 multiparous Holstein dairy cows throughout 3 experimental periods [i.e., period 1=3 wk antepartum up to 12 wk postpartum, period 2=3 wk of feed restriction starting at around 100 d in milk with a control (n=25) and feed-restricted group (50% of energy requirements; n=25), and period 3=subsequent realimentation period for 8 wk]. Milk adiponectin was investigated among 21 multiparous cows at wk 2 and wk 12 of period 1 and wk 2 of period 2. Adiponectin concentrations in plasma and skim milk were measured using an in-house ELISA specific for bovine adiponectin. Major changes in circulating adiponectin concentrations were observed during the periparturient period, whereas energy deficiency during established lactation at around 100 d in milk and subsequent refeeding did not affect plasma adiponectin. Together with lower adiponectin concentrations in milk (µg/mL), the reduction in milk yield led to decreased adiponectin secretion via milk (mg/d) at the second week of feed restriction. Irrespective of time and treatment, milk adiponectin represented about 0.002% of total milk protein. Mean adiponectin concentrations in milk (0.61 ± 0.03 µg/mL) were about 92% lower than the mean plasma adiponectin concentrations (32.1 ± 1.0 µg/mL). The proportion of the steady-state plasma adiponectin pool secreted daily via milk was 2.7%. In view of the similar extent of NEB in both periods of energy deficiency, decreasing adiponectin concentrations seems important for accomplishing the adaptation to the rapidly increasing metabolic rates in early lactation, whereas the lipolytic reaction toward feed restriction-induced NEB during established lactation seems to occur largely independent of changes in circulating adiponectin.

Cholesterol metabolism, transport, and hepatic regulation in dairy cows during transition and early lactation

The transition from the nonlactating to the lactating state represents a critical period for dairy cow lipid metabolism because body reserves have to be mobilized to meet the increasing energy requirements for the initiation of milk production. The purpose of this study was to provide a comprehensive overview on cholesterol homeostasis in transition dairy cows by assessing in parallel plasma, milk, and hepatic tissue for key factors of cholesterol metabolism, transport, and regulation. Blood samples and liver biopsies were taken from 50 multiparous Holstein dairy cows in wk 3 antepartum (a.p.), wk 1 postpartum (p.p.), wk 4 p.p., and wk 14 p.p. Milk sampling was performed in wk 1, 4, and 14 p.p. Blood and milk lipid concentrations [triglycerides (TG), cholesterol, and lipoproteins], enzyme activities (phospholipid transfer protein and lecithin:cholesterol acyltransferase) were analyzed using enzymatic assays. Hepatic gene expression patterns of 3-hydroxy-3-methylglutaryl-coenzyme A (HMGC) synthase 1 (HMGCS1) and HMGC reductase (HMGCR), sterol regulatory element-binding factor (SREBF)-1 and -2, microsomal triglyceride transfer protein (MTTP), ATP-binding cassette transporter (ABC) A1 and ABCG1, liver X receptor (LXR) α and peroxisome proliferator activated receptor (PPAR) α and γ were measured using quantitative RT-PCR. Plasma TG, cholesterol, and lipoprotein concentrations decreased from wk 3 a.p. to a minimum in wk 1 p.p., and then gradually increased until wk 14 p.p. Compared with wk 4 p.p., phospholipid transfer protein activity was increased in wk 1 p.p., whereas lecithin:cholesterol acyltransferase activity was lowest at this period. Total cholesterol concentration and mass, and cholesterol concentration in the milk fat fraction decreased from wk 1 p.p. to wk 4 p.p. Both total and milk fat cholesterol concentration were decreased in wk 4 p.p. compared with wk 1 and 14 p.p. The mRNA abundance of genes involved in cholesterol synthesis (SREBF-2, HMGCS1, and HMGCR) markedly increased from wk 3 a.p. to wk 1 p.p., whereas SREBF-1 was downregulated. The expression of ABCA1 increased from wk 3 a.p. to wk 1 p.p., whereas ABCG1 was increased in wk 14 p.p. compared with other time points. In conclusion, hepatic expression of genes involved in the biosynthesis of cholesterol as well as the ABCA1 transporter were upregulated at the onset of lactation, whereas plasma concentrations of total cholesterol, phospholipids, lipoprotein-cholesterol, and TG were at a minimum. Thus, at the gene expression level, the liver seems to react to the increased demand for cholesterol after parturition. Whether the low plasma cholesterol and TG levels are due to impaired hepatic export mechanisms or reflect an enhanced transfer of these compounds into the milk to provide essential nutrients for the newborn remains to be elucidated.

Bovine Staphylococcus aureus: Subtyping, evolution, and zoonotic transfer.

Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies using ribosomal spacer (RS)-PCR, however, demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infections are genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. Furthermore, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. In addition to RS-PCR, other methods for subtyping Staph. aureus are known, including spa typing and multilocus sequence typing (MLST). They are based on sequencing the spa and various housekeeping genes, respectively. The aim of the present study was to compare the 3 analytic methods using 456 strains of Staph. aureus isolated from milk of bovine intramammary infections and bulk tanks obtained from 12 European countries. Furthermore, the phylogeny of animal Staph. aureus was inferred and the zoonotic transfer of Staph. aureus between cattle and humans was studied. The analyzed strains could be grouped into 6 genotypic clusters, with CLB, CLC, and CLR being the most prominent ones. Comparing the 3 subtyping methods, RS-PCR showed the highest resolution, followed by spa typing and MLST. We found associations among the methods but in many cases they were unsatisfactory except for CLB and CLC. Cluster CLB was positive for clonal complex (CC)8 in 99% of the cases and typically positive for t2953; it is the cattle-adapted form of CC8. Cluster CLC was always positive for t529 and typically positive for CC705. For CLR and the remaining subtypes, links among the 3 methods were generally poor. Bovine Staph. aureus is highly clonal and a few clones predominate. Animal Staph. aureus always evolve from human strains, such that every human strain may be the ancestor of a novel animal-adapted strain. The zoonotic transfer of IMI- and milk-associated strains of Staph. aureus between cattle and humans seems to be very limited and different hosts are not considered as a source for mutual, spontaneous infections. Spillover events, however, may happen.

Staphylococcus aureus genotype B and other genotypes isolated from cow milk in European countries

Staphylococcus aureus is globally one of the most important pathogens causing contagious mastitis in cattle. Previous studies, however, have demonstrated in Swiss cows that Staph. aureus isolated from bovine intramammary infection is genetically heterogeneous, with Staph. aureus genotype B (GTB) and GTC being the most prominent genotypes. In addition, Staph. aureus GTB was found to be contagious, whereas Staph. aureus GTC and all the remaining genotypes were involved in individual cow disease. The aim of this study was to subtype strains of Staph. aureus isolated from bovine mastitic milk and bulk tank milk to obtain a unified view of the presence of bovine staphylococcal subtypes in 12 European countries. A total of 456 strains of Staph. aureus were subjected to different typing methods: ribosomal spacer PCR, detection of enterotoxin genes, and detection of gene polymorphisms (lukE, coa). Major genotypes with their variants were combined into genotypic clusters (CL). This study revealed 5 major CL representing 76% of all strains and comprised CLB, CLC, CLF, CLI, and CLR. The clusters were characterized by the same genetic properties as the Swiss isolates, demonstrating high clonality of bovine Staph. aureus. Interestingly, CLB was situated in central Europe whereas the other CL were widely disseminated. The remaining 24% of the strains comprised 41 genotypes and variants, some of which (GTAM, GTBG) were restricted to certain countries; many others, however, were observed only once.

Effect of routine claw trimming on claw temperature in dairy cows measured by infrared thermography

Infrared thermography (IRT) was used to assess the effect of routine claw trimming on claw temperature. In total, 648 IRT observations each were collected from 81 cows housed in 6 tiestalls before and 3 wk after claw trimming. The feet were classified as either healthy (nonlesion group, n = 182) or affected with infectious foot disorders (group IFD, n = 142). The maximal surface temperatures of the coronary band and skin and the difference of the maximal temperatures (ΔT) between the lateral and medial claws of the respective foot were assessed. Linear mixed models, correcting for the hierarchical structure of the data, ambient temperature, and infectious status of the claws, were developed to evaluate the effect of time in relation to the trimming event (d 0 versus d 21) and claw (medial versus lateral). Front feet and hind feet were analyzed separately. Ambient temperature and infectious foot status were identified as external and internal factors, respectively, that significantly affected claw temperature. Before claw trimming, the lateral claws of the hind feet were significantly warmer compared with the medial claws, whereas such a difference was not evident for the claws of the front feet. At d 21, ΔT of the hind feet was reduced by ≥ 0.25 °C, whereas it was increased by ≤ 0.13 °C in the front feet compared with d 0. Therefore, trimming was associated with a remarkable decrease of ΔT of the hind claws. Equalizing the weight bearing of the hind feet by routine claw trimming is associated with a measurable reduction of ΔT between the paired hind claws.

Development and validation of a novel pedometer algorithm to quantify extended characteristics of the locomotor behavior of dairy cows

Behavior is one of the most important indicators for assessing cattle health and well-being. The objective of this study was to develop and validate a novel algorithm to monitor locomotor behavior of loose-housed dairy cows based on the output of the RumiWatch pedometer (ITIN+HOCH GmbH, Fütterungstechnik, Liestal, Switzerland). Data of locomotion were acquired by simultaneous pedometer measurements at a sampling rate of 10 Hz and video recordings for manual observation later. The study consisted of 3 independent experiments. Experiment 1 was carried out to develop and validate the algorithm for lying behavior, experiment 2 for walking and standing behavior, and experiment 3 for stride duration and stride length. The final version was validated, using the raw data, collected from cows not included in the development of the algorithm. Spearman correlation coefficients were calculated between accelerometer variables and respective data derived from the video recordings (gold standard). Dichotomous data were expressed as the proportion of correctly detected events, and the overall difference for continuous data was expressed as the relative measurement error. The proportions for correctly detected events or bouts were 1 for stand ups, lie downs, standing bouts, and lying bouts and 0.99 for walking bouts. The relative measurement error and Spearman correlation coefficient for lying time were 0.09% and 1; for standing time, 4.7% and 0.96; for walking time, 17.12% and 0.96; for number of strides, 6.23% and 0.98; for stride duration, 6.65% and 0.75; and for stride length, 11.92% and 0.81, respectively. The strong to very high correlations of the variables between visual observation and converted pedometer data indicate that the novel RumiWatch algorithm may markedly improve automated livestock management systems for efficient health monitoring of dairy cows.

Analysis of behavioral changes in dairy cows associated with claw horn lesions

Detecting lame cows is important in improving animal welfare. Automated tools are potentially useful to enable identification and monitoring of lame cows. The goals of this study were to evaluate the suitability of various physiological and behavioral parameters to automatically detect lameness in dairy cows housed in a cubicle barn. Lame cows suffering from a claw horn lesion (sole ulcer or white line disease) of one claw of the same hind limb (n=32; group L) and 10 nonlame healthy cows (group C) were included in this study. Lying and standing behavior at night by tridimensional accelerometers, weight distribution between hind limbs by the 4-scale weighing platform, feeding behavior at night by the nose band sensor, and heart activity by the Polar device (Polar Electro Oy, Kempele, Finland) were assessed. Either the entire data set or parts of the data collected over a 48-h period were used for statistical analysis, depending upon the parameter in question. The standing time at night over 12 h and the limb weight ratio (LWR) were significantly higher in group C as compared with group L, whereas the lying time at night over 12 h, the mean limb difference (△weight), and the standard deviation (SD) of the weight applied on the limb taking less weight were significantly lower in group C as compared with group L. No significant difference was noted between the groups for the parameters of heart activity and feeding behavior at night. The locomotion score of cows in group L was positively correlated with the lying time and △weight, whereas it was negatively correlated with LWR and SD. The highest sensitivity (0.97) for lameness detection was found for the parameter SD [specificity of 0.80 and an area under the curve (AUC) of 0.84]. The highest specificity (0.90) for lameness detection was present for Δweight (sensitivity=0.78; AUC=0.88) and LWR (sensitivity=0.81; AUC=0.87). The model considering the data of SD together with lying time at night was the best predictor of cows being lame, accounting for 40% of the variation in the likelihood of a cow being lame (sensitivity=0.94; specificity=0.80; AUC=0.86). In conclusion, the data derived from the 4-scale-weighing platform, either alone or combined with the lying time at night over 12 h, represent the most valuable parameters for automated identification of lame cows suffering from a claw horn lesion of one individual hind limb.