I. Blanco-Penedo

Metal accumulation in cattle raised in a serpentine-soil area: Relationship between metal concentrations in soil, forage and animal tissues

Soils developed on serpentine rocks contain high levels of heavy metals such as copper (Cu), nickel (Ni) and chromium (Cr), and are deficient in some macronutrients. The crops and pasture grown on these soils may accumulate high levels of metals, which constitute a potential health hazard for cattle. The aim of this study was to evaluate Cr, Ni and Cu accumulation in cattle raised in a serpentine area in Southwest Europe (Galicia, NW Spain). Samples of liver, kidney and muscle of 41 animals aged 8-12 months were collected at slaughter. Representative samples of soil and forage were taken from 10 farms. Samples were acid-digested and metal concentrations determined by ICP-MS (Cr and Ni) and ICP-AES (Cu). The concentrations of the metals in soils and forage were in the range of those found in serpentine soils in other areas. Accumulation of Cr in animal tissues was generally low and within the normal range. However, 20% of the animals had toxic levels of Ni in kidney and 32% of the animals had liver Cu levels above the acceptable range. Serpentine soils had a significant effect on Ni and Cu accumulation in cattle, and a relatively high percentage of the animals showed tissue levels of Ni and Cu indicative of risk of toxicity.

Non-essential and essential trace element concentrations in meat from cattle reared under organic, intensive or conventional production systems

We evaluated if differences in non-essential and essential trace element accumulation in beef-cattle reared under different systems (including organic, conventional and intensive management) were reflected in the meat derived from these animals. Diaphragm muscle from 166 calves from nine farms were analysed. Muscle cadmium concentrations were low (<10 µg/kg wet weight) and muscle arsenic, mercury and lead levels were below the limits of detection (<12, 2 and 3 µg/kg, respectively) in most (77–97%) samples; there were no significant differences between farms. Essential trace element concentrations in muscle were generally within adequate physiological ranges and, although they varied significantly between farms, this was not apparently related to management practices. There were no significant correlations in element concentrations between muscle and liver or kidney (organ concentrations that better reflect exposure), except for cobalt (positive association) and zinc (negative association). Non-essential and essential trace element concentrations in muscle in the studied animals did not generally reflect differences in exposure. This is particularly relevant for animals reared in systems (such as organic farms) where cattle are exposed to higher levels of non-essential elements (probably due to soil ingestion when grazing) but also can suffer from mineral deficiencies.

Evaluation of organic, conventional and intensive beef farm systems: health, management and animal production

The overall aim of the present study was to analyse and compare organic beef cattle farming in Spain with intensive and conventional systems. An on-farm study comparing farm management practices and animal health was carried out. The study also focussed on a slaughterhouse analysis by comparing impacts on the safety and quality of the cattle products. Twenty-four organic and 26 conventional farms were inspected, and farmers responded to a questionnaire that covered all basic data on their husbandry practices, farm management, veterinary treatments and reproductive performance during 2007. Furthermore, data on the hygiene and quality of 244, 2596 and 3021 carcasses of calves from organic, intensive and conventional farms, respectively, were retrieved from the official yearbook (2007) of a slaughterhouse. Differences found between organic and conventional farms across the farm analysis did not substantially reflect differences between both farm types in the predominant diseases that usually occur on beef cattle farms. However, calves reared organically presented fewer condemnations at slaughter compared with intensive and to a lesser extent with conventionally reared calves. Carcass performance also reflected differences between farm type and breed and was not necessarily better in organic farms.

Influence of breed on blood and tissue copper status in growing and finishing steers fed diets supplemented with copper.

To evaluate the influence of breed on the accumulation of dietary copper (Cu) in tissue, and on blood parameters indicative of Cu status, ten Galician Blond, nine Holstein-Friesian and ten Galician Blond × Holstein-Friesian cross (GB × HF) steers were fed diets supplemented with 35 mg/kg DM of CuSO4 during their growing and finishing periods. Blood samples were taken monthly, and samples of liver, kidney, brain, heart, spleen and muscle were taken at slaughter. Cu concentrations were determined by ICP-AES. Holstein-Friesian calves had significantly higher total liver Cu contents than Galician Blonds and GB × HF crosses (mean 1070, 663 and 868 mg, respectively), combined with higher hepatic Cu concentrations (174, 140 and 166 mg/kg wet weight, respectively). Holstein-Friesian calves had also the highest prevalence (89%) of hepatic Cu concentrations exceeding the toxic limit of 150 mg/kg wet weight. Breed did not have a statistically significant influence on blood parameters. With the exception of the semitendinosus muscle, where Holstein-Friesians (0.790 mg/kg) had significantly higher Cu levels than Galician Blonds (0.541 mg/kg) or GB × HF crosses (0.631 mg/kg), no other statistically significant differences by breed in the extrahepatic tissue Cu distribution were observed. A negative statistical association between carcass performance and the ratio of semitendinosus and liver Cu concentration could indicate that the animals with a better carcass performance (Galician Blonds) could need a higher Cu mobilisation into the muscle, resulting in a lower hepatic storage.

The Interlobular Distribution of Copper in the Liver of Beef Calves on a High-Copper Diet

The aims of the present study were 1) to evaluate the interlobular distribution of copper (Cu) in the liver of beef calves on a high-Cu diet, 2) to determine whether this distribution differs between Galician Blonds and Holstein Friesians, and 3) to determine whether in vivo needle biopsy provides an appropriate measure of overall hepatic Cu status. Liver biopsies were performed before slaughter on twenty-nine 10-month-old beef calves fed growing and finishing diets supplemented with 35 mg/kg of Cu sulfate (10 Galician Blonds, 9 Holstein Friesians, and 10 Galician Blond × Holstein Friesian crosses). At slaughter, samples taken from 6 regions of the liver (the internal and external faces of the right lobe; the left, caudate, and quadrate lobes; and the processus papillaris) were acid digested, and their Cu contents were determined by inductively coupled plasma atomic emission spectrometry. The highest Cu concentrations were found in the left lobe, followed by the processus papillaris, and the lowest Cu concentrations were found in the caudate and quadrate lobes. Different breeds differ in absolute hepatic Cu levels, but interlobular Cu distribution does not appear to depend on breed, at least when Galician Blonds are compared with Holstein Friesians. In vivo needle biopsy afforded accurate estimates of overall hepatic Cu status.

Organochlorine pesticide and polychlorinated biphenyl in calves from north-west Spain.

The aim of the present study was to assess the levels of organic pollutants in cattle from the NW of Spain. The livers of 101 animals from two regions (Galicia and Asturias) were analysed for seven organochlorine pesticides (HCB, α-HCCH, φ-HCCH, HEOD, DDT, TDE) and 34 PCBs congeners (8, 18, 28, 29, 31, 52, 77, 101, 105, 114, 118, 123, 126, 128, 138, 141, 149, 153, 156, 157, 167, 169, 170, 171, 180, 183, 187, 189, 194, 199, 201, 205, 206 and 209). The influence of different factors (type of farm and proximity to industrial areas) on pesticide accumulation in cattle was also studied. Overall, the frequency of occurrence and concentrations of OC pesticides and PCBs was low in calves from both regions. HEOD was detected most frequently and was found in more than half of the calves from each region. PCBs 141 and 153 were the most frequently detected PCB congeners but typically occurred in less than 20% of animals. The exposure of calves to the more abundant contaminants differed significantly between the regions and may be related to past usage patterns. Differences between farms in terms of their livestock management did not have a significant effect on pesticide accumulation by calves. The liver concentrations in calves were below maximum residues levels (RMLs) for human intake and there is no indication of any risk from these contaminants through eating calf liver.

Comparison of Bovine coronavirus–specific and Bovine respiratory syncytial virus–specific antibodies in serum versus milk samples detected by enzyme-linked immunosorbent assay

Bovine coronavirus (BCV; Betacoronavirus 1) and Bovine respiratory syncytial virus (BRSV) are significant causes of enteric and respiratory disease in beef and dairy cattle throughout the world. Indirect enzyme-linked immunosorbent assays are widely used to detect serum antibodies for herd monitoring and prevalence studies. In dairy herds, milk is more readily collected than serum. Hence, in order to investigate the test agreement between serum and milk, both serum and milk samples from 105 cows in 27 dairy herds were analyzed in parallel for presence of immunoglobulin G antibodies to BCV and BRSV. The Bland–Altman analyses of data demonstrated good agreement between serum and milk antibody titers for both viruses. The results indicate milk samples are sufficient for surveillance of antibodies to BCV and BRSV.