Flaviana Gottardo

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.

Effect of type of housing on veal calf growth performance, behaviour and meat quality

A study compared the traditional housing of veal calves in individual crates (IC) with group pen housing (GP). Thirty-four pure Holstein male calves (67.6±4.9 kg LW) imported from Poland were used, of which 16 were kept tethered in IC while the remaining animals were housed in six pens of three calves each. The growth trial lasted 142 days during which the calves were fed only a milk replacer diet. Calves health, average daily gain (ADG) and feed efficiency (FE) were similar between types of housing throughout the trial. However, GP calves had higher ADG (1387 vs. 1317 g/day; P<0.05) and better FE (1.83 vs. 1.94; P<0.05) than IC calves in the last 72 days of the trial. Behavioural measurements were taken at the 10th week of the study. The GP calves were allowed to adopt more comfortable resting postures and displayed increased social behaviour than the IC calves. Haemoglobin in samples taken at the end of the growing cycle was higher in GP than in IC calves (10.9 vs. 7.7 g/100 ml; P<0.01). At slaughter, the dressing percentage was unaffected by the housing system, but GP calves showed a better carcass conformation than IC calves. Meat quality evaluation was carried out on the Longissimus thoracis muscle. The meat of GP calves had lower intramuscular fat content (3.92 vs. 6.85% DM; P<0.01) and showed a better tenderness and flavour than that of the IC calves. Consistent with the haemoglobin data, the calves reared in group pens produced carcasses and meat with a darker colour than calves in individual crates.

Effects of illicit dexamethasone upon hepatic drug metabolizing enzymes and related transcription factors mRNAs and their potential use as biomarkers in cattle.

In cattle fattening, the illicit use of growth promoters (GPs) represents a major problem. The synthetic corticosteroid dexamethasone (DEX) is the GP mostly used, alone or in combination with other steroids or beta-agonists. Recently, GPs were shown to disrupt some cattle cytochromes P450 (CYPs) at the post-transcriptional level; therefore, the effects of two illicit protocols containing DEX (alone or together with 17beta-estradiol, 17betaE) upon main cattle liver drug metabolizing enzymes (DMEs) mRNAs and related transcription factors were investigated by quantitative real time RT-PCR. Eleven genes, out of the 18 considered, were significantly modulated by GPs. Corticosteroid-responsive genes did not respond univocally, whereas retinoic X receptor alpha (RXRalpha) and estrogen receptor alpha (ERalpha) were upregulated depending on the illicit protocol used. Nowadays, an increasing interest has been noticed toward the detection of biomarkers of response (BMRs) to be used in the screening of GPs misuse in cattle farming. In the present study, CYP2B6-like, CYP2E1, glutathione S-transferase A1- and sulfotransferase A1-like (GSTA1- and SULT1A1-like) mRNAs were significantly modulated regardless of the GP, the illicit protocol, and the animal breed, representing promising BMRs. The usefulness of these BMRs needs to be characterized more in depth.

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.

Effects of feeding propylene glycol to mid-lactating dairy cows

Propylene glycol (PG) is a gluconeogenic precursor widely used to prevent and treat ketosis postpartum. The study has investigated the effects of PG administration to dairy cows at mid stage of lactation. According to a 3 × 3 latin square design, three Italian Brown lactating cows (125 ± 7 days in milk) fitted with rumen cannula were fed a corn silage based diet (CP 14.7%, NDF 41.1% DM) with 0, 200 or 400 g day−1 PG added. Dry matter intake was increased by feeding PG with a significant quadratic component per dose (16.2, 17.2 and 16.5 kg day−1 for 0, 200 and 400 g PG day−1, respectively). Milk yield was not affected by PG, averaging 17.1 kg day−1. Average daily gain increased from 64 to 206 and 302 g day−1 when cows received 200 and 400 g day−1 of PG (linear component per dose P < 0.05). Digestibility of the diet did not differ among treatments, whereas repeated rumen fluid samples, taken 0, 2, 4, 6 and 8 h after the meal, showed a consistently lower acetate to propionate ratio when feeding PG. Blood insulin was not affected by PG administration. Except for therapeutic treatments, PG administration to dairy cows at mid stage of lactation should be advised against. Despite the positive effect on intake, administration of the additive, increasing the molar percentage of rumen propionate, contributes to shift the energy partition from milk production to liveweight gain.

Tail docking and the rearing of heavy pigs: The role played by gender and the presence of straw in the control of tail biting. Blood parameters, behaviour and skin lesions

This study evaluated whether the specific heavy pig rearing context allowed the fattening of undocked pigs without an outbreak of tail biting. At the same time, gender and straw availability (small amounts) were considered to understand their possible interactions with tail presence in the display of tail biting. A 2 × 2 × 2 factorial design was adopted to test the effects of these factors on blood parameters, behaviour and tail/ear lesions. Few interactions among factors were detected. Undocked pigs showed lower cortisol (P<0.02), lying behaviour (P<0.001), and higher risk of tail/ear biting (weeks 3 and 9), but lower risk of tail lesions (week 14). Straw increased the motivation for exploring (P<0.001), reduced serum haptoglobin (P<0.001) and the risk for tail biting (weeks 3, 9, 18) and ear biting (weeks 3, 9). Results highlight the importance of straw as an environmental enrichment and seem to indicate that fattening undocked heavy pigs is possible.

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.