Marta Brscic

Short communication: Reference values for blood parameters in Holstein dairy cows: Effects of parity, stage of lactation, and season of production

Confidence intervals for blood parameters used for nutritional and metabolic profile testing in cattle were calculated for clinically normal lactating Holstein cows, taking into account the effects of parity, stage of lactation, and season. Blood samples were collected from 740 cows in 33 Italian dairy herds according to a predefined protocol. Herds were visited during summer and the following winter, sampling 12 lactating cows at each visit (4 primiparous and 8 multiparous). Six cows were selected from the early-lactation group (days in milk: 10 to 89) and the other 6 were selected from the mid-lactation group (days in milk: 90 to 215). Cow selection criteria excluded animals clinically exposed to periparturient diseases as well as animals not considered in good health by a veterinary clinical examination. For each blood variable, outliers were identified and discarded. Data were then analyzed for their Gaussian distribution and variables with not normal distribution were log-transformed to adjust for lack of normality. Herd mean values were calculated for each blood parameter according to 3 main classification factors: parity (primiparous vs. multiparous), stage of lactation (early vs. mid) and season of production (summer vs. winter). The resulting data set was statistically analyzed using a mixed model with the fixed effects of these factors, their interactions, and the random effect of herd. General 95% confidence intervals were calculated for blood variables that showed a relevant herd variance component such as albumin, triglycerides, aspartate, urea, glucose, alanine aminotransferase, lactate dehydrogenase, direct and total bilirubin, calcium, magnesium, and potassium. For the remaining parameters, specific confidence intervals were calculated for each level of the significant main factors. Parity affected blood concentration of total protein, globulin, creatinine, alkaline phosphatase, gamma glutamyl transferase, creatinine kinase, and phosphorus. Blood nonesterified fatty acids, aspartate aminotransferase, gamma glutamyl transferase, creatinine kinase and cholesterol were influenced by stage of lactation. The season of production had a significant effect on total protein, globulin, creatinine, alkaline phosphatase, phosphorus, sodium, and chlorine. The outcomes of this work will improve the accuracy of the biochemical profile as a tool for dairy practitioners to assess the metabolic status of lactating Holstein cows.

Prevalence of gastrointestinal disorders recorded at postmortem inspection in white veal calves and associated risk factors

The study aimed at assessing the prevalence of poor rumen development, presence of rumen plaques, rumen papillae hyperkeratinization, and abomasal lesions in veal calves and to investigate risk factors for their occurrence at the farm level. Within a wide cross-sectional study, a sample of 170 veal farms representative of the European veal meat production systems was considered in the 3 major producing countries (99 in the Netherlands, 47 in France, and 24 in Italy). An average of 59 ± 10 (SD) rumens and abomasa belonging to calves from a single batch per farm were inspected at the abattoir by trained observers to assess the incidence of these gastrointestinal disorders. Potential risk factors for their occurrence related to farm management, housing, and to the feeding plan were obtained by a questionnaire submitted to the stockperson. Prevalence of poor rumen development (almost no papillae present), rumen plaques, and hyperkeratinization were 60.4, 31.4, and 6.1% of rumens, respectively, whereas abomasal lesions in the pyloric area were recorded in 74.1% of abomasa. Independent variables related to the feeding system confirmed to be the main risk factors for the occurrence of gastrointestinal disorders in veal calves. However, additional risk sources for each given problem were identified among housing and management variables. The provision of a low amount of solid feed (≤ 50kg of dry matter/head per cycle) was a relevant risk for rumen underdevelopment. Rumen wall alterations (plaques and hyperkeratinization) and abomasal lesions were instead associated with the administration of large quantities of solids (151-300 kg of dry matter/head per cycle) in calves receiving milk replacer during the entire fattening cycle. Among the types of solid feed, cereal grain acted as a preventive measure for low rumen development, whereas it was a risk factor for the occurrence of rumen plaques, papillae hyperkeratinization, and abomasal lesions. Some housing and management options adopted to improve veal calf welfare (i.e., higher space allowance and use of heating) were associated with lower risk for gastrointestinal disorders.

Prevalence of respiratory disorders in veal calves and potential risk factors

The study aimed to assess the in vivo and postmortem prevalence of respiratory disorders in veal calves and investigate risk factors associated with them. A cross-sectional study was carried out in 174 farms in the 3 major veal meat-producing countries in Europe (50 in France, 100 in the Netherlands, and 24 in Italy). Trained veterinarians visually evaluated individual calves of 1 batch per farm at 3 and 13 wk after arrival and at 2 wk before slaughter to assess the prevalence of hampered respiration, nasal discharge, and coughing. A random sample of lungs belonging to calves of the same batch was monitored at the slaughterhouse for mild to moderate or severe signs of pneumonia, and presence of pleuritis. Data regarding veal calf housing, feeding, and management and specific characteristics of the batch were collected through an interview with the stockperson, and the potential of these as respiratory disease risk factors was assessed. Regardless of the stage of fattening, the prevalence of in vivo signs of respiratory disorders in calves was always <7%. This low prevalence was likely the outcome of the general implementation by veal producers of standardized practices such as prophylaxis, all-in/all-out, and individual daily checks of the calves, which are recognized tools for effective disease prevention and management. However, at postmortem inspection, 13.9% and 7.7% of lungs showed mild to moderate and severe signs of pneumonia, respectively, and 21.4% of the inspected lungs had pleuritis. Thus, even mild clinical signs of respiratory disorder in calves at specific time points during the fattening period may be associated with high prevalence of lungs with lesions at slaughter. Alternatively, clinical symptoms recorded during routine visual inspections of veal calves on-farm may be poor predictors of the true prevalence of respiratory disease in calves. Among all potential risk factors considered, those concerning the characteristics of the batch were predominant but factors related to housing, management and feeding equipment were also relevant. Different risk factors were involved at different stages of the fattening period. Therefore, to overcome respiratory disorders in veal calves, different solutions may apply to different stages of the fattening period.

Main critical factors affecting the welfare of beef cattle and veal calves raised under intensive rearing systems in Italy: a review

Abstract This review describes the principal causes of poor welfare in beef cattle and veal calves raised in intensive husbandry systems in Italy. Nowadays there are no specific regulations in force for beef cattle welfare. However, a document produced in 2001 by the Scientific Committee on Animal Health and Animal Welfare of the European Commission on Health and Consumer Protection identified the main causes of inadequate welfare levels in the different cattle rearing systems in Europe. In Italy and in the Po Valley in particular, the beef cattle farms are mainly finishing units characterised by animals kept at high density in multiple pens and fed high starch diets. Under these rearing conditions the limited space allowance is one of the most important issues impairing animal welfare. Other risk factors for poor welfare related to the housing structures are type of floor, space at the manger, number of water dispensers and lack of specific moving and handling facilities. Microclimatic conditions can be critical especially during the summer season when cattle can experience heat stress. The feeding plan adopted in the Italian beef farms may be another factor negatively affecting the welfare of these animals due to the low content of long fibre roughage which increases the risk of metabolic acidosis. In the veal calf rearing systems there has been a mandatory introduction of the new system of production according to the European Council Directives 91/629/EEC and 97/2/EC. Farms had to adopt group housing and to provide calves with an increasing amount of fibrous feed in addition to the all-liquid diet. Despite this specific legislation, several risk factors for calves’ welfare can still be identified. Some of them are related to the housing system (type of floor, air quality, feed and water supply equipment and lack of loading facilities) and some others to the feeding plan (type and amount of roughage, quality of milk replacers). Recent studies have shown that the welfare of veal calves and beef cattle can be severely affected by the quality of the stockmanship and particularly by negative human-animal interaction.

Welfare assessment: correlations and integration between a Qualitative Behavioural Assessment and a clinical/ health protocol applied in veal calves farms

Abstract This study is aimed at finding correlations and possible integration among Qualitative Behavioural Assessment (QBA) and a specific protocol of clinical/health evaluation. Both welfare assessment methods were based on direct animal observation and were applied in 24 Italian veal calves farms at 3 weeks (wks) of rearing. Principal component analysis (PCA) summarized 20 QBA descriptors on two main components (PC1 and PC2) with eigenvalues above 4 and explaining 29.6 and 20.3% of the variation respectively. PCA on residuals obtained after correcting for housing condition yielded highly similar results, indicating that the rearing environment of the calves was not an important determinant of the observer reliability of QBA. A relationship was found between QBA PC2 and the presence of signs of cross-sucking recorded during the clinical visit (presence PC2=1.11 vs. absence PC2=-1.55, P<0.001). There were no other relations between the quantitative clinical measures and QBA PC’s. The frequency of farmer, veterinarian, or industry technician visits to the veal unit significantly affected QBA PC1 and PC2 scores. These results suggest that the 2 methods provide complementary types of information and can each make valid a contribution to an integrated animal welfare monitoring scheme.

Administration of dexamethasone per os in finishing bulls. I. Effects on productive traits, meat quality and cattle behaviour as indicator of welfare

The study investigated the effects of prolonged oral administration of dexamethasone at a low daily dosage of 0.75 mg/head per day (Dexa) on beef cattle productive traits, behaviour and meat quality. In all, 14 finishing Marchigiana bulls were used in a trial that begun 56 days prior to slaughter, of which six bulls received treatment from day 5 to day 53, whereas the remaining animals were used for Control. The animals treated showed an increased average daily gain (1515 v. 1177 g/head per day; P < 0.05; s.e.d. = 48.54) and improved warm carcass dressing percentage (60.8% v. 59.7%; P < 0.05; s.e.d. = 0.32). Behavioural observation did not permit a clear distinction between treated and Control animals since feeding and social behaviour were similar in both groups. The bulls treated spent less time lying (16.5% v. 34.6%; P < 0.05; s.e.d. = 4.38) and grooming (6.7% v. 11.9%; P < 0.05; s.e.d. = 1.23), and this may indicate poorer welfare. No evidence of treatment was observed in other carcass traits, and redness was the only meat quality parameter slightly affected by corticosteroid administration.

The relationship between clinical signs of respiratory system disorders and lung lesions at slaughter in veal calves

The presence and severity of lung lesions recorded post-mortem is commonly used as an indicator to assess the prevalence of respiratory problems in batches of bovines. In the context of a welfare monitoring based on on-farm measures, the recording of clinical signs on calves at the farm would be more convenient than the recording of lung lesions at slaughter. The aim of the present study was to investigate the relationship between clinical respiratory signs at farm and post-mortem analyses of lung lesions observed at slaughter in veal calves. If clinical signs were a good predictor of lung lesions it could be possible to integrate only those measures in a welfare monitoring system. One-hundred-and-seventy-four batches of calves were observed 3 times: at 3 and 13 weeks after arrival of the calves at the unit and at 2 weeks before slaughter. For each batch a maximum of 300 calves was observed and the proportions of calves showing abnormal breathing, nasal discharge and coughing were recorded. Post-mortem inspection was carried out on a sample of lungs belonging to calves from the observed batches. Each examined lung was classified according to a 4-point scale for pneumonia from healthy lung (score 0) to severe lesions (score 3). The clinical signs recorded infra vitam were significantly correlated with moderate and severe lung lesions for observations at 13 weeks and 2 weeks before slaughter and the level of the correlation was highly variable (r(sp) from 0.16 to 0.40). Receiver operating characteristic (ROC) curves were created and the area under the curves showed that batches with a high proportion of lungs with moderate or severe lesions could not be accurately detected by the three clinical signs of respiratory disorders. These results suggest that both clinical signs and post-mortem inspection of lung lesions must be included in a welfare monitoring schemes for veal calves.

Administration of dexamethasone per os in finishing bulls. II. Effects on blood parameters used as indicators of animal welfare.

A set of hormonal, haematological and biochemical parameters was used to evaluate the physiological response and welfare status of 14 finishing Marchigiana bulls treated for 49 days with a low daily dosage (0.75 mg/head per day) of dexamethasone per os. Compared to the Control group, dexamethasone decreased cortisol concentrations (42.3 v. 5.7 nmol/l; s.e.d. = 4.17; P < 0.001), and led to the reversal of the leukocyte formula in the animals treated (P < 0.05). Total serum proteins (70.2 v. 73.9 g/l; s.e.d. = 1.55; P < 0.05), in particular β1 globulins (7.5 v. 9.1 g/l; s.e.d. = 0.24; P < 0.01) and fibrinogen (199 v. 258 mg/dl; s.e.d. = 32.70; P < 0.05), increased as a consequence of treatment. Prolonged dexamethasone administration led the bulls to an apparently chronic stress condition. Moreover, the study indicated various blood parameters that might be used by health officials as effective tools in identifying beef cattle suspected of being illegally treated with dexamethasone.

Can novel methods be useful for pain assessment of castrated piglets

Given that surgical castration is a painful practice performed on millions of pigs every year, a need to identify novel reliable pain assessment tools exists in order to test anaesthetic and analgesic protocols that may reduce related pain. Two treatments were considered: handling (H) and surgical castration (C). Physiological (cortisol, lactate, glycaemia, rectal and eye temperature) and behavioural variables (latency to move after treatment and alterations in posture and walking) were analysed. Cortisol showed the greatest level in C piglets within 20 min after the surgical procedure and a positive correlation with glucose concentration. Eye temperature was higher in C piglets, and the same difference was detected for rectal temperature 3 h after castration. Behavioural parameters revealed that C piglets had longer latency to move and a higher percentage of them showed alterations in posture and walking. Results of this study showed that, in castrated piglets behavioural and physiological alterations occur mainly in the first 3 h from treatment. Latency to move, alterations in posture and walking, and eye temperature appear to give additional and useful information in piglet pain assessment. However, differently from the behavioural parameters considered, eye temperature involves several manipulations of the animals and a long process to acquire the data.

Comparison of two feeding finishing treatments on production and quality of organic beef

The study compared growth and slaughter performance and meat quality of organic beef cattle finished with or without pasture grazing. One group of 10 Limousin heifers was finished under confined conditions and fed ad libitum a total mixed ration based on maize silage, hay and cereal grains. A second group of 10 Limousin heifers rotationally grazed two contiguous pasture plots of 1.5 ha each with a daily supplementation of a concentrate mix based on cereal grains and roasted soybeans. Heifers were slaughtered at commercial finishing and meat quality traits were assessed on Longissimus thoracis muscle. The grazing group, due to a lower average daily gain (0.74 vs. 0.95 kg/day; P<0.05), required a prolonged finishing period (172 vs. 155 days; P<0.05) than the confined animals. Meat samples from grazing cattle were less tender (shear force: 3.92 vs. 3.24 kg/cm2; P<0.05) and showed a lower lightness (L*: 33.0 vs. 35.8; P<0.001) and a higher redness (15.4 vs. 13.7; P<0.01) and yellowness (15.6 vs. 14.6; P<0.05). Fatty acid composition of the intramuscular fat was significantly affected by the finishing system. Grazing heifers had a higher content of polyunsaturated fatty acids (4.06 vs. 3.66% of total fatty acids; P<0.05), conjugated linoleic acids (0.16 vs. 0.10% of total fatty acids; P<0.01) and ω-3 (0.44 vs. 0.30% of total fatty acids; P<0.001) than confined animals. The detrimental effects of pasture grazing on growth performance and on some important meat quality traits explain the limited adoption of this finishing system in organic beef production.