Understanding diversity of hepatic metabolism and related adaptations in the early lactating dairy cow.

The onset of lactation in dairy cows represents a major metabolic challenge that involves large adaptations in glucose, fatty acid, and mineral metabolism to support lactation and to avoid metabolic dysfunction. The complex system of adaptation can differ considerably between cows, and may have a genetic base. In the present review, the variation in adaptive reactions in dairy cows is discussed. In these studies, the liver being a key metabolic regulator for understanding the variation in adaptive performance of the dairy cow was the main focus of research. Liver function was evaluated through gene expression measurements; to explain the associated phenotypic variability and to identify descriptors for metabolic robustness in dairy cows. Hence, the identified genes involved act as a connecting link between the genotype encoded on the DNA and the phenotypic expression of the target factors at a protein level. The integration of phenotypic data, including gene expression profiles, and genomic data will facilitate a better characterization of the complex interplay between these levels, and will improve the genetic understanding necessary to unravel a certain trait or multi-trait such as metabolic robustness in dairy cows.

Different adaptation of IGF-I and its IGFBPs in dairy cows during a negative energy balance in early lactation and a negative energy balance induced by feed restriction in mid-lactation

Control of metabolic pathways is a major task of the somatotropic axis and its constituents. Insulinlike growth-factor binding proteins (IGFBPs) bind IGF-I and -II and act as carriers and regulators of their activities in blood, body fluids and tissues. Over two periods of physiological adaptation, this study investigated the binding pattern of IGF-I to IGFBPs in the plasma of 50 multiparous Holstein dairy cows and identified relationships with the hepatic mRNA abundance of IGFBPs and plasma IGF-I during the lactational negative energy balance (NEB) and during a deliberately induced NEB by feed restriction. Period 1 lasted from week 3 antepartum (a.p.) to week 12 postpartum (p.p.) and period 2, the period of feed restriction, started at around 100 DIM and lasted for three weeks with a control (C) and a restricted group (R). Blood samples and liver biopsies were collected in week 3 a.p., and in weeks 1 and 4 p.p. of period 1 and in weeks 0 and 3 of period 2. For column chromatography of IGFBPs, plasma samples of all animals were pooled by group and time points of sampling. Plasma IGF-I dropped from week 3 a.p. to week 1 p.p. and thereafter increased until week 0 (period 2) and did not change up to week 3 of period 2. The binding of IGF-I to plasma IGFBP-1 and -2 increased in period 1 from week 3 a.p. to week 4 p.p., while at the same time it decreased for IGFBP-3. During period 2, the binding of IGF-I to plasma IGFBP-1 and -2 decreased for both groups, but less for R cows. In C cows, the IGF-I binding to IGFBP-3 in plasma increased from week 0 to week 3 of period 2, whereas R cows showed a slight decrease. In period 1, hepatic mRNA abundance of IGFBP-3 followed the plasma IGFBP-3 binding in contrast to the mRNA abundances of IGFBP-1 and -2. The latter increased from week 3 a.p. to week 1 p.p. and decreased afterwards whereas IGF-I binding to IGFBP-1 and -2 increased. In week 3 of period 2, the binding of IGF-I to IGFBP-1 and -2 and their hepatic mRNA abundance were higher in R cows compared to C cows. Hepatic mRNA abundance of IGF-I was consistently positively correlated with plasma IGF-I, especially pronounced during the NEBs in week 1 p.p. (period 1) and in week 3 (period 2) in R cows. While no distinct relation between mRNA abundance of IGFBP-1 and plasma IGF-I was evident, the mRNA abundance of IGFBP-2 was inversely related to plasma IGF-I over all experimental time points independent of treatment. The mRNA abundance of IGFBP-3 was particularly correlated with plasma IGF-I during the 2 experimental stages of a NEB. Obviously IGFBP-3, but not IGFBP-1 and -2, binding in plasma closely followed the respective pattern of hepatic mRNA abundance during the entire experimental period. The fact that changes in the different plasma IGFBPs during altering metabolic stages in different stages of lactation do not always strictly follow their mRNA abundance in liver suggests tissues other than the liver flexibly contributing to the IGFBP pool in plasma as well as a partially post-transcriptional regulation of IGFBP synthesis.

A field trial of infrared thermography as a non-invasive diagnostic tool for early detection of digital dermatitis in dairy cows

Infrared thermography (IRT) was used to detect digital dermatitis (DD) prior to routine claw trimming. A total of 1192 IRT observations were collected from 149 cows on eight farms. All cows were housed in tie-stalls. The maximal surface temperatures of the coronary band (CB) region and skin (S) of the fore and rear feet (mean value of the maximal surface temperatures of both digits for each foot separately, CBmax and Smax) were assessed. Grouping was performed at the foot level (presence of DD, n=99; absence, n=304), or at the cow level (all four feet healthy, n=24) or where there was at least one DD lesion on the rear feet, n=37). For individual cows (n=61), IRT temperature difference was determined by subtracting the mean sum of CBmax and Smax of the rear feet from that of the fore feet. Feet with DD had higher CBmax and Smax (P<0.001) than healthy feet. Smax was significantly higher in feet with infectious DD lesions (M-stage: M2+M4; n=15) than in those with non-infectious M-lesions (M1+M3; n=84) (P=0.03), but this was not the case for CBmax (P=0.12). At the cow level, an optimal cut-off value for detecting DD of 0.99°C (IRT temperature difference between rear and front feet) yielded a sensitivity of 89.1% and a specificity of 66.6%. The results indicate that IRT may be a useful non-invasive diagnostic tool to screen for the presence of DD in dairy cows by measuring CBmax and Smax.

Current attitudes of bovine practitioners, claw-trimmers and farmers in Switzerland to pain and painful interventions in the feet in dairy cattle.

The attitudes of bovine practitioners, claw-trimmers and farmers towards painful therapeutic claw-trimming of dairy cattle were surveyed and differences between the respondents were assessed. A total of 77 farmers and 32 claw-trimmers were interviewed, and 137 bovine practitioners completed an equivalent online survey. No veterinary consultation for common painful interventions in the feet of cattle was reported by 52% of farmers (i.e. procedures in these herds were performed without local anaesthesia). Only ≈30% of practitioners always carried out such interventions under local anaesthesia and, in general, practitioners considered pain reduction to the lowest possible level less important than did farmers. Furthermore, 47% of practitioners and 33% of claw-trimmers, compared to only 11% of farmers, agreed with the statement that the cost of pain management was a major concern for farmers. There was a particular lack of awareness by farmers regarding the obligation to carry out painful therapeutic claw-trimming under analgesia and the application of local anaesthesia during the trimming of sole ulcers was considered reasonable by significantly fewer farmers (41.6%) and claw-trimmers (46.9%), than practitioners (78.6%). Overall, the attitudes of those involved in painful therapeutic claw-trimming contrasted with Swiss national legislation and with farmer opinion on the importance of reducing pain to the lowest level possible.

Questionnaire-based study to assess the association between management practices and mastitis within tie-stall and free-stall dairy housing systems in Switzerland.

BACKGROUND Prophylactic measures are key components of dairy herd mastitis control programs, but some are only relevant in specific housing systems. To assess the association between management practices and mastitis incidence, data collected in 2011 by a survey among 979 randomly selected Swiss dairy farms, and information from the regular test day recordings from 680 of these farms was analyzed. RESULTS The median incidence of farmer-reported clinical mastitis (ICM) was 11.6 (mean 14.7) cases per 100 cows per year. The median annual proportion of milk samples with a composite somatic cell count (PSCC) above 200,000 cells/ml was 16.1 (mean 17.3) %. A multivariable negative binomial regression model was fitted for each of the mastitis indicators for farms with tie-stall and free-stall housing systems separately to study the effect of other (than housing system) management practices on the ICM and PSCC events (above 200,000 cells/ml). The results differed substantially by housing system and outcome. In tie-stall systems, clinical mastitis incidence was mainly affected by region (mountainous production zone; incidence rate ratio (IRR) = 0.73), the dairy herd replacement system (1.27) and farmers age (0.81). The proportion of high SCC was mainly associated with dry cow udder controls (IRR = 0.67), clean bedding material at calving (IRR = 1.72), using total merit values to select bulls (IRR = 1.57) and body condition scoring (IRR = 0.74). In free-stall systems, the IRR for clinical mastitis was mainly associated with stall climate/temperature (IRR = 1.65), comfort mats as resting surface (IRR = 0.75) and when no feed analysis was carried out (IRR = 1.18). The proportion of high SSC was only associated with hand and arm cleaning after calving (IRR = 0.81) and beef producing value to select bulls (IRR = 0.66). CONCLUSIONS There were substantial differences in identified risk factors in the four models. Some of the factors were in agreement with the reported literature while others were not. This highlights the multifactorial nature of the disease and the differences in the risks for both mastitis manifestations. Attempting to understand these multifactorial associations for mastitis within larger management groups continues to play an important role in mastitis control programs.

[Mastitis management in Swiss dairy farms with udder health problems]

The objective of this study was to describe the udder health management in Swiss dairy herds with udder health problems. One hundred dairy herds with a yield-corrected somatic cell count of 200'000 to 300'000 cells/ml during 2010 were selected. Data concerning farm structure, housing system, milking technique, milking procedures, dry-cow and mastitis management were collected during farm visits between September and December 2011. In addition, quarter milk samples were collected for bacteriological culturing from cows with a composite somatic cell count ≥ 150'000 cells/ml. The highest quarter level prevalence was 12.3 % for C. bovis. Eighty-two percent of the pipeline milking machines in tie-stalls and 88 % of the milking parlours fulfilled the criteria for the vacuum drop, and only 74 % of the pipeline milking machines met the criteria of the 10-l-water test. Eighty-five percent of the farms changed their milk liners too late. The correct order of teat preparation before cluster attachment was carried out by 37 % of the farmers only. With these results, Swiss dairy farmers and herd health veterinarians can be directed to common mistakes in mastitis management. The data will be used for future information campaigns to improve udder health in Swiss dairy farms.

Conception Rate Using the Select-Synch Protocol in Combination with a Lower Dose Progesterone-Releasing Intravaginal Insert (1.38 g) in Swiss Dairy Cows

Background: Synchronization programs have become standard in the dairy industry. In Switzerland, these programs are used but newly. The objective of this study was A) to estimate the pregnancy rate after a Select-Synch protocol in- cluding a low dosage of progesterone in CIDR (1.38 g). As a second step B) this pregnancy rate should be compared to cows from another Swiss study that used a Select-Synch protocol with the 1.9 g insert (Rudolph et al., 2011). Methods: A) 196 cows were included in the study. Cows received a CIDR 1.38 g and 2.5 ml of buserelin i.m. on d 0. On d 7, the CIDR insert was removed and 5 ml of dinoprost was administered i.m. On d 0 a milk sample for progesterone analysis was taken. Pregnancy was determined at or more than 35 days after artificial insemination. B) The 1.38 g group and the 1.9 g group were compared as to cow and farm factors, number of preceding AI’s, gynecological and uterine pretreat- ment and treatment itself. A forward selection procedure was used (test result considered significant if p-value  0.05). Results: A) The pregnancy rate, using the Select-Synch protocol with the CIDR 1.38 g was 44.4%. B) The CIDR 1.9 g Select-Synch group revealed a pregnancy rate of 50.4% (Rudolph et al., 2011). Significant differences between the groups were not found. Conclusion: The 1.38 g CIDR-Select-Synch protocol may be recommended for multiparous dairy cows. The pregnancy rate compared to the 1.9 g CIDR-Select-Synch protocol was 8% lower, but this difference was not significant.

Influence of manure scrapers on dairy cows in cubicle housing systems

Manure scrapers are widely used in dairy cow loose-housing systems. In order to evaluate the effects of the scrapers on the cows, we assessed their impact on the animals' cardiac activity, feeding behaviour, and the behavioural reactions of cows confronted with different types of scrapers. In part I of the study, we measured cardiac activity (mean R–R interval and RMSSD, a parameter of heart-rate variability) whilst observing the behaviour of 29 focal cows on three farms during situations with and without active manure scrapers. Lower RMSSD values were observed during scraping events while cows were either lying, standing or walking in the alleyway, standing completely in the lying cubicle, or standing half in the lying cubicle (P=0.03), but only tended to differ while directly confronted with the scraper (P=0.06). This indicates that dairy cows experienced at least some mild stress during manure-scraping events. In part II, the feeding behaviour of 12 cows on each of two farms was recorded by means of a jaw-movement sensor and compared between situations with the manure-scraping event following forage provision either within or outside the main daily feeding period (i.e. within 1 or after 2 h from forage provisioning, respectively). The duration of night-time feeding (P=0.049) and the number of feeding bouts (P=0.036) were higher when a manure-scraping event took place within the main daily feeding period, indicating that the cows' feeding behaviour had been disturbed. In part III, we observed the cows' behaviour on 15 farms during eight manure scraping events per farm, where each of five farms had one of three different scraper types. We assessed the cows' immediate reactions when confronted with the scraper. In addition, we recorded the number of animals present in the alleyways before and after the manure-scraping events. The more cows that were present in the alleyways before the scraping event, the lower the proportion of cows showing direct behavioural reactions both with (P=0.017) and without (P=0.028) scraper contact, and the higher the number of cows that left the alleyways (P<0.001). Scraper type did not influence the proportion of cows showing behavioural reactions. In conclusion, our results show that dairy cows perceive the manure-scraping event negatively in some situations, that feeding behaviour may be disturbed when scrapers are active during the main feeding period, and that cows avoid the scraper during crowded situations.

Lameness and foot lesions in Swiss dairy cows: I. Prevalence.

Prevalences of foot lesions and lameness were recorded in 1'449 Swiss dairy cows during routine claw-trimming on 78 farms from June 2010 until February 2011. Lameness was present in 14.8 % of cows and on 80.8 % of investigated farms. Highest prevalences were seen for widened white line (80.7 %/100 %), signalling foot lesion (65.6 %/98.7 %), heel-horn erosion (34.2 %/88.5 %), digital dermatitis complex (29.1 %/73.1 %), severe hemorrhages (27.9 %/87.2 %), and Rusterholz' sole ulcers (11.5 %/74.4 %) at cow and herd level, respectively. Lower prevalences were found for subclinical laminitis (5.4 %/47.4 %), chronic laminitis (3.3 %/25.6 %), white line disease (4.7 %/42.3 %), double soles (2.6 %/33.3 %), interdigital hyperplasia (3.1 %/33.3 %), sole ulcers (0.4 %/6.4 %), toe infections caused by faulty claw-trimming (3.9 %/39.7 %) and by injury (0.1 %/2.6 %), deep lacerations (0.4 %/6.4 %), and interdigital phlegmona (0.1 %/1.3 %). Lameness and foot lesions were shown to represent important health problems of dairy cows under the conditions of the typical grass-based production system in Switzerland. Digital dermatitis has developed to the most relevant foot disease with a high impact on welfare of Swiss dairy cows within the past 10 years.

Lameness and foot lesions in Swiss dairy cows: II. Risk factors.

The objective of this study was to evaluate risk factors associated with foot lesions and lameness in Swiss dairy cows. Potential risk factors were recorded by means of examination of 1'449 Swiss cows and the management systems of 78 farms during routine claw-trimming, and during personal interviews with the associated farmers. Statistical analysis of animal-based and herd level risk factors were performed using multivariate logistic regression models. The risk of being lame was increased in cows affected by digital dermatitis complex, heel-horn erosion, interdigital hyperplasia, Rusterholz' sole ulcer, deep laceration, double sole and severe hemorrhages. Cleanliness, BCS, affection with other foot lesions, breed, importance of claw health to the farmer, frequency of routine claw-trimming, producing according to the guidelines of the welfare label program RAUS, and silage feeding were shown to be associated with the occurrence of some of the evaluated foot lesions and lameness. The identified risk factors may help to improve management and the situation of lameness and claw health in dairy cows in Switzerland and other alpine areas with similar housing and pasturing systems.

Detection of enterotoxigenic Escherichia coli in foods by polymerase chain reaction

Enterotoxigenic Escherichia coli (ETEC) causes significant morbidity and mortality in infants of developing countries and is the most common cause of diarrhea in travelers to these areas. Enterotoxigenic Escherichia coli infections are commonly caused by ingestion of fecally contaminated food. A timely method for the detection of ETEC in foods would be important in the prevention of this disease. A multiplex polymerase chain reaction (PCR) assay which has been successful in detecting the heat-labile and heat-stable toxins of ETEC in stool was examined to determine its utility in foods. This PCR assay, preceded by a glass matrix and chaotropic DNA extraction, was effective in detecting high numbers of ETEC in a variety of foods. Ninety percent of 121 spiked food samples yielded positive results. Samples of salsa from Guadalajara, Mexico and Houston, Texas were collected and underwent DNA extraction and PCR. All samples yielded negative results for both the heat-labile and heat-stable toxins. Samples were also subjected to oligonucleotide probe analysis and resulted in 5 samples positive for ETEC. Upon dilution testing, it was found that positive PCR results only occurred when 12,000 to 1,000,000 bacteria were present in 200 mg of food. Although the DNA extraction and PCR method has been shown to be both sensitive and specific in stool, similar results were not obtained in food samples. ^

Gammaglobulin and selenium status in healthy neonatal dairy calves in Switzerland

Serum samples from 142 calves and their dams were analyzed for gammaglobulins (gammaG, calves) and selenium concentrations (Se, calves and dams). A questionnaire provided information about birth and colostrum management. The calves and their dams were distributed into two groups according the calves' gammaG concentration (< 10 and >= 10 g/L), Se concentrations were compared between groups. The correlation between gammaG and Se concentrations in the calves and their dams was analyzed. Risk factors for failure of passive transfer and Se deficiency were assessed based on the questionnaire. The gammaG concentration of 42.9 % of the calves was < 10 g/L (median: 10.9). Calves showed significantly higher gammaG values after optimized colostrum administration than calves with suboptimal colostrum administration (p < 0.004). The median Se concentration was 26.8 and 36.5 microg/L for the calves and dams, respectively. A high correlation was observed between the Se concentration of the dam and her calf (r = 0.72, p < 0.001). The calves' Se and gammaG concentrations were not significantly correlated. These results demonstrate that further efforts toward better information of farmers regarding colostrum management and Se supply are warranted.

A longitudinal study investigating the prevalence of Staphylococcus aureus genotype B in seasonally communal dairy herds

Abstract Staphylococcus aureus is a major mastitis-causing pathogen. Various genotypes have been recently identified in Switzerland but Staph. aureus genotype B (GTB) was the only genotype associated with high within-herd prevalence. The risk of introducing this Staph. aureus genotype into a herd may be increased by frequent animal movements. This may also be the case when cows from different herds of origin are commingled and share their milking equipment for a limited period of time. The aim of the present study was to determine the prevalence of Staph. aureus GTB in seasonally communal dairy herds before and after a summer period when dairy farming is characterized by mixing cows from different herds of origin in 1 communal operation. In addition, the environment was investigated to identify potential Staph. aureus GTB reservoirs relevant for transmission of the disease. A total of 829 cows from 110 herds of origin in 9 communal operations were included in the study. Composite milk samples were collected from all cows during the first or second milking after arrival at the communal operation and again shortly before the end of the season. Swab samples from the environment, involved personnel, and herding dogs present were collected before the cows arrived. At the end of the season, sampling of personnel was repeated. All samples were analyzed for the presence of Staph. aureus GTB using an established quantitative PCR. At the beginning of the season, Staph. aureus GTB-positive cows were identified in 7 out of 9 communal operations and the within-communal operation prevalence ranged from 2.2 to 38.9%. At the second sampling, all communal operations were Staph. aureus GTB positive, showing within-communal operation prevalence from 1 to 72.1%. The between-herd of origin prevalence increased from 27.3 to 56.6% and the cow-level prevalence increased from 11.2% at the beginning of the season to 29.6% at the end of the season. On 3 different communal operations, Staph. aureus GTB-positive swabs from seasonally employed personnel were identified at the end of the season. The results indicate that Staph. aureus GTB can easily spread in communal operations when cows from different herds of origin are mixed during the summer season. Effective management measures need to be designed to prevent the spread of Staph. aureus GTB in seasonally communal herds. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved. KEYWORDS: Staphylococcus aureus; biosecurity; communal herd; epidemiology