Association of clinical respiratory disease signs and lower respiratory tract bacterial pathogens with systemic inflammatory response in pre-weaned dairy calves.

This study investigated the potential associations between 3 acute phase proteins (APPs) haptoglobin, serum amyloid A, and fibrinogen, clinical signs of respiratory disease, and the presence of bacterial pathogens in the lower respiratory tract (LRT) of pre-weaned dairy calves. This cross-sectional study included 150 pre-weaned calves (2-86 d old) from 15 large dairy herds in Estonia. Tracheobronchial lavage, blood, and fecal samples were collected from 5 calves showing clinical signs indicative of LRT disease, and samples from 5 calves without clinical signs of LRT disease per herd. All samples collected from these calves were analyzed for concentrations of systemic APPs, LRT bacteria, and intestinal pathogens. Heifer blood and bulk tank milk samples were collected for the detection of disease-specific antibodies against bovine herpesvirus 1, bovine viral diarrhea virus, bovine respiratory syncytial virus, and Mycoplasma bovis. Mixed-effects linear regression models were used to analyze the associations of clinical respiratory disease signs and LRT bacteria with APPs. Increased plasma fibrinogen concentrations in calves were associated with higher rectal temperature (>39.5°C), increased respiratory rate (>50 breaths/min), and coughing. Increased serum amyloid A concentrations were associated with higher rectal temperature (>39.5°C) and respiratory rate between 40 and 50 breaths/min. Calves with the presence of fecal Cryptosporidium spp. and rectal temperature of 39°C and above had increased serum haptoglobin concentrations. Increased fibrinogen concentrations were associated with the presence of Pasteurella multocida in the calf LRT, whereas increased concentrations of fibrinogen and serum amyloid A were associated with the presence of Trueperella pyogenes. In conclusion, APPs showed variable associations with clinical signs of respiratory disease and LRT bacteria. Plasma fibrinogen concentration could be used as a complementary calf-side test to assess systemic inflammation caused by LRT bacteria such as P. multocida and T. pyogenes in pre-weaned dairy calves.

Local and Systemic Inflammation in Finnish Dairy Cows with Digital Dermatitis.

Digital dermatitis is a disease of the digital skin and causes lameness and welfare problems in dairy cattle. This study assessed the local and systemic inflammatory responses of cows with different digital dermatitis lesions and compared macroscopical and histological findings. Cow feet (n = 104) were evaluated macroscopically and skin biopsies histologically. Serum samples were analyzed for acute phase proteins (serum amyloid A and haptoglobin) and pro-inflammatory cytokines (interleukin-1 beta, interleukin-6, and tumor necrosis factor-alpha). Cows with macroscopically graded active lesions (p = 0.028) and non-active lesions (p = 0.008) had higher interleukin-1 beta levels in their serum compared to healthy cows. Interleukin-1 beta serum concentrations were also higher (p = 0.042) when comparing lesions with necrosis to lesions without necrosis. There was no difference when other cytokine or acute phase protein concentrations in healthy cows were compared to those in cows with different digital dermatitis lesions. A novel histopathological grading was developed based on the chronicity of the lesions and presence of necrosis and ulceration. The presence and number of spirochetes were graded separately. In the most severe chronic lesions, there was marked epidermal hyperplasia and hyperkeratosis with necrosis, deep ulceration, and suppurative inflammation. Spirochetes were found only in samples from necrotic lesions. This study established that digital dermatitis activates proinflammatory cytokines. However, this did not initiate the release of acute phase proteins from the liver. A histopathological grading that takes into account the age and severity of the lesions and presence of spirochetes was developed to better understand the progression of the disease. It is proposed that necrosis of the skin is a result of ischemic necrosis following reduced blood flow in the dermal papillae due to pressure and shear stress caused by thickened epidermis, and that the spirochetes are secondary invaders following tissue necrosis.

Application of multiblock analysis to identify key areas and risk factors for dairy cow persistence.

The present study analysed the importance of individual variables and different thematic blocks of production areas, management, and herd infectious disease status on cow persistence, characterised by herd on-farm mortality rate (MR), culling rate (CR), and mean age of culled cows (MAofCC) applying multiblock partial least squares (mbPLS) analysis. This study included 120 free-stall dairy herds with ≥ 100 cows. Data on the previous year's predominant cow housing system and management practices were collected, and on-farm measurements and cow scoring were performed. Bulk tank milk (BTM) and heifer blood samples (10 samples per herd) were collected and analysed for antibodies against the selected pathogens. In total, 172 variables were aggregated into 14 thematic blocks. The annual CR, MR, and MAofCC values were calculated for each herd. Thematic blocks with significant impact on cow persistence (included herd MR, CR and MAofCC) were 'infectious diseases' (block importance index out of all blocks = 13.6%, 95% CI 10.3; 20.5), 'fertility management' (16.3%, 95% CI 6.8; 26.9), 'lactating cow management' (11.5%, 95% CI 6.4; 17.8), 'milking' (11.3%, 95% CI 3.2; 17.1), 'herd characteristics' (10.1%, 95% CI 6.3; 14.2), 'close-up period management' (9.7%, 95% CI 2.7; 15.7), 'calving management' (7.9%, 95% CI 3.1; 11.4) and 'disease management' (7.3%, 95% CI 0.2; 12.0). Variable categories with the highest importance in explaining composite outcome including herd MR, CR and MAofCC were rear-end and udder lesions in ≥ 20% of the cows, BTM and heifers seropositive to bovine respiratory syncytial virus, vaccination against bovine herpesvirus 1, twice daily milking and herd location in Northwest region. Larger herd size, higher levels of milk yield, and rearing predominantly Holstein breed cattle were herd factors associated with poorer cow persistency. Grazing cows and having semi-insulated barns were associated with lower CR and MR, respectively. Heat detection and farm pregnancy testing strategies were significant factors in the fertility block. Using disposable dry papers for teat cleaning and not using any wet teat-cleaning tools were risk factors for high MR. A robotic milking system was protective for increased herd MR and CR. A high pre-calving body condition score and poor rear body cleanliness of ≥ 30% of cows were associated with inferior herd persistency outcomes. Calving in group pens with deep litter bedding was associated with a lower CR. Multiblock PLS model is innovative tool that helped to identify most influential farming areas but also single risk factors associated with cow persistency described by multiple parameters.

Associations of neonatal acute phase response with first lactation performance in dairy cows.

During the first 3 wk of life, the immune system of newborn ruminants starts to work, as indicated by fluctuations in the concentrations of proinflammatory cytokines and acute phase proteins (APP). They have been shown to be markers for short and long-term weight gain in ruminants. This observational study investigated these proteins as possible indicators of first lactation performance of dairy cows. A total of 117 dairy calves from a single farm were enrolled in the study. Serum and fecal samples were taken once a week for the first 3 wk of life. Cryptosporidium spp. infection and its treatment were monitored and accounted for in statistical analysis. The concentrations of the APP serum amyloid A (SAA) and haptoglobin (Hp), and the proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) were analyzed in serum. After the first lactation, health and performance data of the cows were retrieved, and associations between APP and cytokine concentrations with first lactation outcomes were investigated through linear and logistic regression. This study found a negative association between the concentration of Hp in the second week of life and average daily weight gain at one year. The SAA concentration measured during the second and third weeks of life was positively associated with age at first calving. IL-6, SAA, and Hp measured in the second week of life were positively associated with calving to conception interval. The concentrations of IL-6 and TNF-α during the first week of life were associated with higher odds of reproductive issues during the first lactation period. These markers can be used to help understand underlying processes that influence animal health and production. In conclusion, inflammatory responses during the first week of life are related to reproductive success, whereas the second and third weeks of life seem to influence the future productive performance in dairy cows.

Faecal microbiota in two-week-old female dairy calves during acute cryptosporidiosis outbreak - Association with systemic inflammatory response.

In the present study, relationships between the intestinal microbiota and innate immunity response, acute cryptosporidiosis, and weight gain in female dairy calves were investigated. A total of 112 calves born during a natural outbreak of cryptosporidiosis on one dairy farm was included in the study. Microbiota composition was analysed by means of 16S ribosomal RNA gene amplicon sequencing from faecal samples collected during the second week of life, while the status of Cryptosporidium spp. infection was determined using immunofluorescence. Serum samples from the second week of life were colourimetrically analysed for the following markers of acute inflammation: acute-phase proteins (serum amyloid A and haptoglobin) and pro-inflammatory cytokines (interleukin-1 beta, interleukin-6, and tumour necrosis factor-alpha). Statistical analyses were performed using random forest analysis, variance-partitioning, and negative binomial regression. The faecal microbiota of the two-week old calves was composed of the phyla Firmicutes, Bacteroidetes, Proteobacteria, Fusobacteria, and Actinobacteria (in order of decreasing abundance). Microbial diversity, measured in terms of the Shannon index, increased with the age of the calves and decreased if a high count of Cryptosporidium spp. oocysts was found in the faeces. Fusobacterium was positively associated with Cryptosporidium spp. oocyst count and serum amyloid A concentration. Peptostreptococcus was positively associated with haptoglobin and serum amyloid A concentrations, and negatively associated with average daily weight gain at 9 months of age. The markers of innate immunity, in combination with age, explained 6% of the microbial variation. These results suggest that some components of the intestinal microbiota may have a long-lasting negative effect on animal growth through the stimulation of the systemic innate immune response.

Acute phase response of sole ulcer, white line disease and digital dermatitis in dairy cows.

Hoof disorders cause lameness and welfare problems for dairy cattle. Acute phase proteins, including serum amyloid A and haptoglobin, with increased rectal temperature and interleukin-6 concentrations, are markers of acute phase response. This study assessed the inflammatory response of cows with either sole ulcer, white line disease or digital dermatitis compared to healthy cows. Another aim was to monitor the inflammatory response changes over time after diagnosis (at hoof trimming, seven and 14 days later) in cows with different hoof disorders. Serum amyloid A concentration in cows with sole ulcer was significantly higher compared with the control group (cows with no hoof lesions) within the two-week study period. Interleukin-6 and rectal temperature declined from day zero to day seven in the sole ulcer group. These results suggest that sole ulcers initiate a long lasting systemic inflammatory response in dairy cows.

Effect of colostrum on the acute-phase response in neonatal dairy calves.

The core part of the mammal innate immune system is the acute-phase response (APR), during which acute-phase proteins (APP) are synthesized. Colostrum contains immunomodulating factors such as proinflammatory cytokines and APP in large quantities. We looked at proinflammatory cytokines [IL-1ß, IL-6, and tumor necrosis factor-α (TNF-α)] and APP [serum amyloid A (SAA) and haptoglobin (Hp)] in colostrum and in calves' serum. The aim of this study was to evaluate the effects of colostrum on the calves' systemic APR and the associations of the calves' serum APR with short- and long-term weight gain (at the age of 1, 3, and 9 mo). A total of 143 female dairy calves were studied during their first 3 wk of life. The calves were separated from their mothers immediately after birth and bottle-fed 3 L of quality-controlled colostrum once within 2 h after birth. Serum samples were collected once a week during the first 3 wk of life (a total of 1-3 samples per calf). Mean sampling age (±standard deviation) was 4.3 (±2.0) d in the first week, 11.0 (±2.0) d in the second week, and 18.0 (±2.0) d in the third week. Linear regression models were used to study associations of colostrum APP and cytokine concentration with serum APR markers and for studying associations of colostrum and serum APR markers with calves' average daily weight gain (ADWG). Mixed linear regression models were used to compare serum concentrations of APR markers by study weeks. The colostrum IL-6 concentrations were positively associated with serum IL-6 in the first 3 wk of life. Colostrum IL-1ß was positively associated with calves' serum IL-1ß during the first week of life, and colostrum TNF-α was positively associated with calves' serum TNF-α during the first 2 wk of life. Serum IL-1ß concentrations differed over the 3 wk, being the highest during the first week and the lowest during the second week. For IL-6, the concentration during the first week was the highest, and for TNF-α, a steady decline in the concentration was observed. Serum SAA concentrations were elevated during the first 2 wk of life and subsequently declined during the third week. Albumin concentrations were lowest in the first week, whereas Hp concentrations were highest during the second week. Serum concentrations of SAA, Hp, IL-6, and TNF-α during the second week were negatively associated with ADWG at 9 mo of age. The SAA concentrations during the third week of age had a negative association with 9-mo ADWG. Serum Hp concentrations in the third week were negatively associated with 3-mo ADWG. The results of our study suggest that colostrum cytokines influence calf serum cytokine concentrations. Thus, they influence the newborn calves' adaptation to the environment and the development of their immune system. Factors that activate an APR during the second and third week of life have a long-term influence on calves' development.

Attitudes and personality of farm managers and association with cow culling rates and longevity in large-scale commercial dairy farms.

The farmer has the central role in determining cow culling policies on their farm and thus affecting cow longevity. The present study aimed to examine farm managers´ satisfaction, attitudes, personality traits and analyse the associations with dairy cow culling and longevity in large commercial dairy farms. Farm managers of 116 dairy herds rearing at least 100 cows in freestall barns were included. A questionnaire for the farm managers registered personal background information of respondent and included statements capturing their satisfaction, opinions and attitudes regarding dairy cow culling and longevity, farming in general, and a Ten Item Personality Inventory scoring. For each herd, the last 12 months cow culling rate (CR, excluding dairy sale) and herd mean age of culled cows (MAofCC) was obtained from the Estonian Livestock Performance Recording Ltd. A K-mean clustering algorithm was applied to subgroup farm managers based on their attitudes, opinions and personality traits. The yearly mean herd CR was 33.0% and MAofCC was 60.6 months. Farm managers´ were mostly dissatisfied with cow longevity and culling rates in their farms. Dissatisfaction with culling rates and longevity, priority for producing high milk yields over longevity and production-oriented attitude was associated with high culling rates and poor longevity. Farm managers' personality had an effect on herd culling rates and their attitudes explained one third of the variability of culling rates and longevity. Explaining the economic consequences of high culling rates and decreased longevity, improving the visibility of these parameters together with benchmarking could bring these issues into focus.

Seroprevalence of selected endemic infectious diseases in large-scale Estonian dairy herds and their associations with cow longevity and culling rates.

Herd culling rates and longevity represent herd health and welfare status as well as farm economic performance. The contribution of endemic circulation of the main cattle pathogens to herd performance has not been previously analysed. The aim of this study was to estimate the herd prevalence of selected endemic bovine pathogens among large commercial dairy herds and to analyse their associations with herd culling rates and longevity. Bulk tank milk (BTM) samples and 10 heifer serum samples were collected from 120 Estonian dairy herds with at least 100 cows, between August 2019 and July 2020. All samples were tested for antibodies against bovine herpesvirus 1 (BHV-1), bovine viral diarrhoea virus (BVDV), bovine respiratory syncytial virus (BRSV), Mycoplasma bovis, Mycobacterium avium spp. paratuberculosis (MAP) and Salmonella Dublin using commercial ELISA. Data on herd size, milk yield, culling rate (CR) and mean age of the culled cows (MAofCC) were collected from the Estonian Livestock Performance Recording Ltd. The apparent herd and animal prevalences were calculated, and linear regression models were used to identify associations between the herd status of six tested pathogens and CR and MAofCC. The herd seroprevalences for antibodies based on BTM and heifer serum sample testing were BHV-1 56.7 % (95 % CI 47.3; 65.7), Mycoplasma bovis 48.3 % (95 % CI 39.1; 57.6), MAP 2.5 % (95 % CI 0.5; 7.1) and S. Dublin 24.2 % (95 % CI 16.8; 32.8) in all tested herds. Excluding vaccinated herds, herds prevalence for BVDV was 27.0 % (95 % CI 19.0; 36.3) and for BRSV 94.7 % (95 % CI 88.1; 98.3). Herd seropositive status for BRSV was associated with lower MAofCC, and herds with BSRV-seropositive youngstock had increased CR. Herds with positive BTM test results for S. Dublin culled cows at an older average age (Coef = 3.79 months, 95 % CI 0.52; 7.07, p = 0.023). MAP-positive herds had somewhat lower herd MAofCC (Coef = -6.18 months, 95 % CI -12.98; 0.63, p = 0.075). There was also a tendency of BVDV-negative herds to have a lower CR than BVDV-positive herds (Coef = -3.03 %, 95 % CI -6.54; 0.49, p = 0.090), and vaccination against BVDV tended to be protective against high CR (Coef = -6.26 %, 95 % CI -12.61; 0.09, p = 0.053 compared to infected herds). This study shows that Estonian large-scale dairy herds are endemically infected with several important cattle pathogens. Most of the studied pathogens influence longevity and culling rates, thus entailing health and economic consequences.

Culling reasons and risk factors in Estonian dairy cows.

BACKGROUND: Culling is a major cost for dairy farms but also an essential part in managing herd productivity. This study aimed to identify the culling rates of Estonian dairy cows, identify the farmers' stated reasons and risk factors for culling. This observational study used registry data of all cows from herds with ≥20 cow-years in 2013-2015. Cow lactation-level analyses included data of 86,373 primiparous cows from 409 herds and 177,561 lactations of 109,295 multiparous cows from 410 herds. Weibull proportional hazard regression models were used to identify risk factors for culling due to slaughter or death. RESULTS: The overall culling rate of Estonian dairy cows was 26.24 (95% CI 26.02; 26.46) per 100 cow-years. The most common reasons farmers stated for culling were feet/claw disorders (26.4%), udder disorders (22.6%), metabolic and digestive disorders (18.1%) and fertility problems (12.5%). Animal-level risk factors for culling were Holstein breed, older parity, lower milk yield breeding value, older age at first calving, longer previous calving interval, having assisted calving, stillbirth and birth of twins/triplets. Lower milk yield, somatic cell count over 200,000 cells/ml and fat/protein ratio over 1.5 at first test-milking after calving were associated with greater culling hazard during the lactation. Cows from larger herds, herds with decreasing size and higher milk yields had a higher culling probability. CONCLUSIONS: This study emphasises the need for improved management of hoof health and prevention of mastitis and metabolic diseases. It is essential to ensure easy calving and good health of cows around calving in order to lower the culling hazard.

Leptospira spp. in Cats in Estonia: Seroprevalence and Risk Factors for Seropositivity.

Leptospirosis is a zoonotic bacterial disease that affects humans and animals worldwide. Recently, more attention has been paid to Leptospira spp. infections in domestic cats. In this seroepidemiological study, we estimated the prevalence of anti-Leptospira spp. antibodies in domestic cats in Estonia and evaluated risk factors for the seropositivity. A total of 546 surplus feline plasma and serum samples, collected in collaboration with small animal clinics and an animal shelter in 2013 and 2015, were included in this study. The samples were tested for antibodies against Leptospira spp. using a microscopic agglutination test. The panel included Leptospira interrogans serovars Pomona, Icterohaemorrhagiae, Bratislava, Canicola, and Hardjo, and Leptospira kirschneri serovar Grippotyphosa. Titers ≥100 (positive reactions at dilutions ≥1/100) were considered positive. Anti-Leptospira spp. antibodies were detected in 12.8% of the cats. The percentage of cats that tested positive for antibodies against L. interrogans serovars Pomona, Icterohaemorrhagiae, Bratislava, Canicola, and Hardjo were 9.3%, 3.5%, 2.4%, 0.4%, and 0.2%, respectively, and the percentage of cats that tested positive for antibodies against L. kirschneri serovar Grippotyphosa was 7.3%. Of the seropositive cats, 46.5%, 35.2%, 12.7%, 4.2%, and 1.4% tested positive for 1, 2, 3, 4, and 5 serovars, respectively. The prevalence of anti-Leptospira spp. antibodies was 11.2% in pet cats and 16.3% in shelter cats. Among pet cats, the seroprevalence was over four times higher in cats that had access to the outdoors (17.2%) than in indoor cats (3.9%). Multivariable models, one based on data on pet cats only and another including also data on shelter cats, identified having access to the outdoors, being a shelter cat, and being from Western Estonia as the risk factors for seropositivity. Cats could be better protected from exposure to Leptospira spp. by not allowing them to roam freely outdoors.

Anti-Ascaris suum IgG antibodies in fattening pigs with different respiratory conditions.

During their migration through the pig's body, Ascaris suum larvae cause significant damage to the lungs. Little is known about the actual impact of this tissue damage on the occurrence and severity of respiratory problems in industrial pig fattening farms. In this study, we evaluated the link between the serological response to two different A. suum antigen preparations and respiratory or meat inspection outcomes. Two different serological tests were used that measure antibodies against either the A. suum haemoglobin molecule or complete homogenate of the 3rd stage larva that migrate through the lungs. Firstly, serum samples were analysed that were collected from 19 herds in which the cause of acute clinical respiratory symptoms was either Actinobacillus pleuropneumoniae, A. suum, or a miscellaneous cause. This was done to test whether serological results could confirm pathological findings. Secondly, serum samples from 60 herds of finishing pigs with a history of high or low frequency of pleuritis at meat inspection (MI), but without acute respiratory symptoms at the time of sampling, were also submitted for serological evaluation using both tests. Regression models were used to search for potential associations between the proportion of pigs testing seropositive with MI results, in particular pathological changes related to the lungs. The results of both ELISAs were strongly associated (P < 0.001) with pigs belonging to a herd where the respiratory problems could be attributed to A. suum by histology, indicating that both tests can be used to diagnose clinical respiratory outbreaks due to A. suum. In the herds without acute clinical respiratory symptoms, a positive association was found between the proportion of pigs testing seropositive and the percentage of livers rejected due to milk spots and with whole carcass condemnations. No association was found between Ascaris serology and lung pathology (pneumonia and pleuritis) registered at MI, however, challenging the likely involvement of Ascaris in the development of these lesions.

Evaluation of butorphanol-azaperone-medetomidine in captive cheetah (Acinonyx jubatus) immobilization.

OBJECTIVE: The butorphanol-azaperone-medetomidine fixed-dose combination (BAM, respectively, 30-12-12 mg mL-1) with subsequent antagonism by naltrexone-atipamezole was evaluated for reversible immobilization of captive cheetahs (Acinonyx jubatus). STUDY DESIGN: Prospective, clinical trial. ANIMALS: Twelve cheetahs (six males and six females, weighing 37-57 kg) housed in enclosures, were immobilized at Hoedspruit Endangered Species Centre in the Republic of South Africa. METHODS: BAM volume dose rate was 0.009-0.014 mL kg-1 (mean ± standard deviation 0.010 ± 0.001 mL kg-1). Total dose in all animals was 0.5 mL. The actual doses were as follows: butorphanol (0.29 ± 0.04 mg kg-1), azaperone (0.12 ± 0.01 mg kg-1) and medetomidine (0.12 ± 0.01 mg kg-1). Physiologic variables and quality of immobilization were recorded every 5 minutes beginning at 15-20 minutes after darting. Arterial blood samples were collected three times at 20, 30 and 40 minutes after darting from all animals for analysis of blood oxygenation and acid-base status. RESULTS: The inductions were calm and smooth and mean induction time was 4.0 ± 1.1 minutes. Heart rate (50 ± 9 beats minute-1) and respiratory frequency (20 ± 3 breaths minute-1) were stable throughout immobilization. The recovery time after reversing with naltrexone and atipamezole was 9.1 ± 3.6 minutes. CONCLUSIONS: and clinical relevance BAM proved to be a reliable and cardiovascular stable drug combination for immobilization of cheetahs.

Molecular epidemiology of Cryptosporidium spp. in calves in Estonia: high prevalence of Cryptosporidium parvum shedding and 10 subtypes identified.

We investigated the molecular epidemiology of Cryptosporidium spp. in Estonia by testing fecal samples from 486 calves aged <2 months, raised on 53 cattle farms, for the presence of Cryptosporidium DNA. The parasites were identified and characterized by sequencing of the 18S rRNA gene and of the 60 kDa glycoprotein (gp60) gene. Moreover, using a questionnaire, we surveyed factors that could be relevant for animal-to-human and human-to-animal transmission of Cryptosporidium spp. on the farms. Cryptosporidium spp. were shed by 23% of the investigated calves and at least one shedding calf was found on 66% of the farms. Cryptosporidium parvum was the most common species shed, while C. bovis and C. ryanae were also detected. More than half of the calves aged 8-14 days shed C. parvum. Nine previously described C. parvum subtypes (IIaA14G1R1, IIaA16G1R1, IIaA17G1R1, IIaA18G1R1, IIaA19G1R1, IIaA20G1R1, IIaA21G1R1, IIaA22G1R1 and IIaA16G2R1) and an apparently novel subtype IIlA21R2 were found. Calves from farms that reported spreading manure on fields during spring had 10 times higher odds to shed Cryptosporidium spp. in their feces than calves from farms that did not. Calves aged 8-14 days had higher odds to shed IIa18G1R1 as well as IIaA16G1R1 than younger calves.

Associations between group sizes, serum protein levels, calf morbidity and growth in dairy-beef calves in a Finnish calf rearing unit.

Efficient dairy-beef production relies on good quality of purchased calves, defined by breed, health, and growth characteristics. Several management factors, such as commingling of calves and large group size, predispose calves to diseases. Acute phase proteins are sensitive detectors of calf diseases. We studied the associations between group size, serum acute phase proteins, immunoglobulin G (IgG), calf morbidity and growth of dairy-beef calves in a random field trial in a calf-rearing unit in Finland. The randomized trial was carried out at a calf rearing unit, where approximately 80 dairy or crossbred calves were allocated either into a single group of 40 calves or into four groups of 10 on arrival at the calf-rearing unit (at age 24.1 SD ± 9.2 days). The study was carried out on 6 arrival batches: 476 calves. Calves were clinically examined and blood sampled on arrival (day 0), and haptoglobin (Hp), serum amyloid A (SAA), albumin and IgG were determined. Calves were weighed on arrival (day 0, average age 24.1 days), at the end of the milk feed period (day 49), at approximately 200 days of age and at slaughter (carcass weight) at 15-18 months of age. During the rearing calves were observed by the farm workers and treated, if necessary, according to predetermined instructions of the veterinary surgeon. All NSAID and antimicrobial treatments were recorded and used as morbidity indicators in statistical analysis. There were no differences in the numbers of antimicrobial treatments or growth among the groups. The majority (84.1%) of antimicrobial treatments were used against respiratory tract infections. Higher concentrations of albumin and IgG on arrival extended the time before the first and the second antimicrobial treatments. Complex relationships between group size, morbidity, concentrations of serum acute phase proteins and IgG at arrival, and growth of calves were explored. Group size of 10 calves did not protect calves from respiratory tract infections, when the small groups were sharing the air space with a large group. An increased SAA concentration on arrival was associated with poorer average daily gain at two rearing periods and with lower carcass weight at slaughter. Serum proteins could be valuable health indicators for purchased calves because they have numerous and variable associations with health and growth. The mechanisms that connect increased SAA concentration and poorer average daily gain over the long term remain unclear.

Acute phase response in organic lambs associated with colostrum serum amyloid A, weight gain, and Cryptosporidium and Giardia infections.

In neonatal period, lamb's immune system goes through rapid adaptation to the extra-uterine environment. Success of this process can influence the animal's future performance and, thus, the quantitative assessment of it would greatly benefit sheep producers. The current study was conducted to investigate the acute phase response (APR) (measured through serum amyloid A (SAA), haptoglobin (Hp) and albumin (ALB)) in relation to later life growth (measured at 122 days of age), and naturally occurring Cryptosporidium and Giardia infections in neonatal lambs grown in organic farm. Serum (n = 692) and faecal (n = 141) samples were collected from 269 lambs in their first 3 weeks of life. The ewes' colostrum (n = 181) SAA concentrations were positively associated with the lambs' serum SAA and Hp concentrations at 2 to 4 days of age. Hp and ALB concentrations at the second week of age were positively associated with the growth rate at 122 days of age. Lamb serum globulin (GLOB) concentrations and Cryptosporidium-positive faecal samples were negatively associated at the second and third weeks of life. These findings suggest the importance of interactions between the immune system and environmental factors at the second week of the lambs' lives and its association with future performance.

Elimination of selected mastitis pathogens during the dry period.

We aimed to evaluate the elimination of 4 different mastitis pathogens, Streptococcus agalactiae, Mycoplasma bovis, Staphylococcus aureus, and Streptococcus uberis, from infected udder quarters during the dry period using quantitative PCR. The second purpose of this study was to evaluate the association between milk haptoglobin (Hp) concentration and the presence of udder pathogens (Strep. agalactiae, Staph. aureus, M. bovis, and Strep. uberis) in udder quarter milk samples before and after dry period. Aseptic udder quarter milk samples (n = 1,001) were collected from 133 dairy cows at dry off and at the first milking after calving from 1 large dairy herd. Bacterial DNA of Strep. agalactiae, Staph. aureus, Strep. uberis, and M. bovis in the udder quarter milk samples was identified with commercial quantitative PCR analysis Mastitis 4B (DNA Diagnostic A/S, Risskov, Denmark). Milk Hp concentration (mg/L) was measured from udder quarter milk samples. The elimination rates during the dry period for M. bovis, Staph. aureus, Strep. agalactiae, and Strep. uberis were 86.7, 93.6, 96.2, and 100.0%, respectively. The new IMI rate was 3.0% for M. bovis, 2.9% for Staph. aureus, 2.4% for Strep. agalactiae, and 3.1% for Strep. uberis. The milk Hp concentration was significantly higher in udder quarter milk samples with blood and in samples positive for Strep. agalactiae at dry off and for Staph. aureus postcalving. Elevated milk Hp concentration was not associated with the presence of M. bovis in the udder quarter milk samples. In conclusion, elimination of Staph. aureus, Strep. agalactiae, and Strep. uberis during the dry period was high; the elimination of M. bovis from infected udder quarters was lower, but probably spontaneous. Additionally, milk Hp concentration may be used as a marker for udder inflammation when combined with the bacteriological results at dry off and postpartum.

Evaluation of butorphanol-azaperone-medetomidine (BAM) in captive blesbok immobilization (Damaliscus pygargus phillipsi).

OBJECTIVE: The fixed-dose combination of butorphanol, azaperone and medetomidine (BAM; 30, 12 and 12 mg mL-1, respectively) with subsequent antagonism by naltrexone-atipamezole was evaluated for reversible immobilization of captive blesbok (Damaliscus pygargus phillipsi). STUDY DESIGN: Prospective, clinical trial. ANIMALS: Sixteen blesbok (four males and twelve females), weighing 52.5-71.0 kg, were immobilized in South Africa. METHODS: The total dose of BAM ranged from 0.5 to 0.7 mL for females and 0.7 to 0.9 mL for males. In seven animals chosen randomly, 8000 units of hyaluronidase was added to the dart. Physiologic variables were recorded every 5 minutes beginning at 10-20 minutes after darting. Arterial blood samples were collected three times at 20, 30 and 40 minutes after darting for analysis of blood acid-base status. RESULTS: The mean administered doses of BAM were as follows: butorphanol (0.34 ± 0.08 mg kg-1), azaperone (0.14 ± 0.03 mg kg-1) and medetomidine (0.14 ± 0.03 mg kg-1). The inductions were calm and smooth. The mean induction time was 9.6 ± 3.2 minutes with just BAM and 5.1 ± 0.8 minutes with BAM and hyaluronidase combination. Heart rate (45 ± 6 beats minute-1) and respiratory frequency (38 ± 4 breaths minute-1) were stable throughout immobilization. The mean arterial blood pressure for all animals was stable but elevated (137 ± 7 mmHg). Rectal temperature slightly increased over time but remained within an acceptable range. The recovery time after administering naltrexone and atipamezole was 4.8 ± 0.7 minutes. CONCLUSION AND CLINICAL RELEVANCE: The BAM combination proved to be reliable and effective in blesbok.

On-farm mortality and related risk factors in Estonian dairy cows.

Mortality (unassisted death and euthanasia) reflects the health and welfare state of the cows and is associated with undesirable financial consequences for the farmer. The objective of this retrospective observational study was to identify risk factors associated with on-farm mortality in dairy cows. Data for a study period between January 1, 2013 and December 31, 2015 were retrieved from the Estonian Agricultural Registers and Information Board and Estonian Livestock Performance Recording, Ltd. Cows from milk-recording herds with ≥20 cow-years were included. Analyses included data of 86,459 primiparous cows from 409 herds and 109,314 multiparous cows from 410 herds. Cows were followed from the day of calving until exit from the herd due to on-farm death or euthanasia (defined as mortality), slaughter, or selling. Associations between risk factors and mortality were assessed using Weibull proportional hazard models. The mortality rate (MR) was lower in primiparous cows (MR = 5.09 per 100 animal-years, 95% confidence interval [CI] 4.93; 5.26) compared to multiparous cows (MR = 8.28 per 100 animal-years, 95% CI 8.13; 8.44). The early lactation period was associated with greater mortality hazard. Animal-level factors significantly associated with higher mortality hazard in primiparous and multiparous cows were Holstein breed, older age at first calving, having an assisted calving or stillborn calf. In multiparous cows, male sex of the calf, birth of twins/triplets, older parity, longer previous inter-calving interval and milk somatic cell count over 200,000 cells/ml at the last test-milking of the previous lactation were associated with greater mortality hazard. Lower milk yield, somatic cell count over 200,000 cells/ml and fat/protein ratio over 1.5 at first test-milking were associated with greater mortality hazard during the lactation. Cow mortality risk was greater in larger herds, in herds with lower cow conception rate and poorer longevity of cows. Also, lower herd average milk fat/protein ratio and decreasing herd size (for multiparous cows) as well as Northeast region were herd level risk factors. This study outlines the importance of herd management and good health of the cows at dry-off and during early lactation and ensuring easy calving to reduce mortality of cows.