This article reports on the effects of elastic (rubber) flooring compared with concrete flooring on claw health and milk yield in dairy cows. Milk yield and activity data of 53 complete lactations from 49 cows were recorded by an automatic milking system in the University of Munich Livestock Center dairy herd. Cows were kept in a loose housing system on concrete-slatted or rubber-matted slatted flooring. Claws were trimmed and measured linearly in combination with claw lesion diagnosis 3 times during one lactation period (including the transition phase). An automatic milking system recorded milk yield and activity. The net horn growth of the claws increased on elastic flooring. Therefore, correct and frequent claw trimming is at least as important for claw health in dairy herds kept on rubber flooring as for those on concrete-slatted flooring. Cows housed on rubber had an increased incidence of sole ulcers. Sole hemorrhages (except for hemorrhages associated with sole ulcers) occurred less frequently on rubber than on concrete. Results concerning digital dermatitis were difficult to assess, because manual manure scraping on rubber required sprinkling the flooring twice daily, which additionally moistened the digital skin of the cows. This might explain the greater incidence of digital dermatitis on elastic flooring. The incidence of clinically lame cows did not differ between flooring types. Cows showed greater activity on rubber, most likely caused by the more comfortable walking surface compared with the concrete-slatted flooring. The greater activity may indicate better overall health of high-yielding dairy cows on rubber flooring. Milk yield, however, did not differ between flooring types.

BackgroundSince the pig is one of the most important livestock animals worldwide, mapping loci that are associated with economically important traits and/or traits that influence animal welfare is extremely relevant for efficient future pig breeding. Therefore, the purpose of this study was a genome-wide mapping of quantitative trait loci (QTL) associated with nine body composition and bone mineral traits: absolute (Fat, Lean) and percentage (FatPC, LeanPC) fat and lean mass, live weight (Weight), soft tissue X-ray attenuation coefficient (R), absolute (BMC) and percentage (BMCPC) bone mineral content and bone mineral density (BMD).MethodsData on the nine traits investigated were obtained by Dual-energy X-ray absorptiometry for 551 pigs that were between 160 and 200 days old. In addition, all pigs were genotyped using Illumina’s PorcineSNP60 Genotyping BeadChip. Based on these data, a genome-wide combined linkage and linkage disequilibrium analysis was conducted. Thus, we used 44 611 sliding windows that each consisted of 20 adjacent single nucleotide polymorphisms (SNPs). For the middle of each sliding window a variance component analysis was carried out using ASReml. The underlying mixed linear model included random QTL and polygenic effects, with fixed effects of sex, housing, season and age.ResultsUsing a Bonferroni-corrected genome-wide significance threshold of P < 0.001, significant peaks were identified for all traits except BMCPC. Overall, we identified 72 QTL on 16 chromosomes, of which 24 were significantly associated with one trait only and the remaining with more than one trait. For example, a QTL on chromosome 2 included the highest peak across the genome for four traits (Fat, FatPC, LeanPC and R). The nearby gene, ZNF608, is known to be associated with body mass index in humans and involved in starvation in Drosophila, which makes it an extremely good candidate gene for this QTL.ConclusionsOur QTL mapping approach identified 72 QTL, some of which confirmed results of previous studies in pigs. However, we also detected significant associations that have not been published before and were able to identify a number of new and promising candidate genes, such as ZNF608.Electronic supplementary materialThe online version of this article (doi:10.1186/s12711-014-0068-2) contains supplementary material, which is available to authorized users.

SummaryThe safety of veterinary vaccines is assessed in clinical trials in Europe. The assessment of the local tissue reaction to vaccination by magnetic resonance imaging (MRI) could reduce the number of animals needed because repeated examinations can be performed in the same animal over time. The present study compared the evaluation of local tissue reactions to vaccination using MRI in live pigs with histopathology of porcine tissue, the current gold standard in regulatory safety testing. Eight piglets each were administered one of two commercial vaccines into marked injection sites. All animals were sedated and scanned repeatedly by MRI using a contrast agent up to day 29 after vaccination. On day 29, the animals were euthanized and underwent a pathological examination. The MRI results were compared with the pathomorphological findings at the injection site by regression analysis. The MR images and the pathological examinations yielded matching results concerning the sizes of the affected tissue volumes or areas. The use of MRI for regulatory safety testing can reduce the number of animals needed to 8 per examination group. The volume of a local reaction and its progression over time can be evaluated and documented. If persistent lesions develop a final pathomorphological examination is needed to identify the kind and local distribution of the reaction.

The objective of the study was to evaluate whether magnetic resonance imaging (MRI) offers the opportunity to reliably analyze body composition of pigs in vivo. Therefore, the relation between areas of loin eye muscle and its back fat based on MRI images were used to predict body composition values measured by dual energy X-ray absorptiometry (DXA). During the study, a total of 77 pigs were studied by MRI and DXA, with a BW ranging between 42 and 102 kg. The pigs originated from different extensive or conventional breeds or crossbreds such as Cerdo Iberico, Duroc, German Landrace, German Large White, Hampshire and Pietrain. A Siemens Magnetom Open was used for MRI in the thorax region between 13th and 14th vertebrae in order to measure the loin eye area (MRI-LA) and the above back fat area (MRI-FA) of both body sides, whereas a whole body scan was performed by DXA with a GE Lunar DPX-IQ in order to measure the amount and percentage of fat tissue (DXA-FM; DXA-%FM) and lean tissue mass (DXA-LM; DXA-%LM). A linear single regression analysis was performed to quantify the linear relationships between MRI-and DXA-derived traits. In addition, a stepwise regression procedure was carried out to calculate (multiple) regression equations between MRI and DXA variables (including BW). Single regression analyses showed high relationships between DXA-%FM and MRI-FA (R 2 5 0.89, OMSE 5 2.39%), DXA-FM and MRI-FA (R 2 5 0.82, OMSE 5 2757 g) and DXA-LM and MRI-LA (R 2 5 0.82, OMSE 5 4018 g). Only DXA-%LM and MRI-LA did not show any relationship (R 2 5 0). As a result of the multiple regression analysis, DXA-LM and DXA-FM were both highly related to MRI-LA, MRI-FA and BW (R 2 5 0.96; OMSE 5 1784 g, and R 2 5 0.95, OMSE 5 1496 g). Therefore, it can be concluded that the use of MRI-derived images provides exact information about important 'carcass-traits' in pigs and may be used to reliably predict the body composition in vivo.