Evaluation of Breeding Value and Selection of Bull Dams in the Danish Dairy Breeds: II. Model Calculations of the Effect of Bias on the Efficiency of Selection

Abstract

Alternative selection strategies in the bull dam path were investigated to reduce the magnitude of bias. The study's objective was to examine the effect of alternative strategies under the assumption of particular biases. Bias in the evaluation of bull dam estimated breeding values (EBVs) causes an estimated reduction of 32% in their genetic superiority, compared with the theoretical potential. Biased evaluations caused selection of too many bull dams from later lactations. Two alternative strategies were developed to account for existing bias. Results suggested that the influence of bias could be reduced. The estimated improvement in selection response was 11–13% higher than current practice. Problems with biased EBVs in conventional breeding schemes are discussed and a method to counteract bias from future breeding schemes is presented.     

Modelling soil carbon sequestration of intensively monitored forest plots in Europe by three different approaches

Information on soil carbon sequestration and its interaction with nitrogen availability is rather limited, since soil processes account for the most significant unknowns in the C and N cycles. In this paper we compare three completely different approaches to calculate carbon sequestration in forest soils. The first approach is the limit-value concept, in which the soil carbon accumulation is estimated by multiplying the annual litter fall with the recalcitrant fraction of the decomposing plant litter, which depends on the nitrogen and calcium content in the litter. The second approach is the N-balance method, where carbon sequestration is calculated from the nitrogen retention in the soil multiplied with the present soil C/N ratio in organic layer and mineral topsoil. The third approach is the dynamic SMART2 model in combination with an empirical approach to assess litter fall inputs. The comparison is done by first validating the methods at three chronosequences with measured C pools, two in Denmark and one in Sweden, and then application on 192 intensive monitoring plots located in the Northern and Western part of Europe. Considering all three chronosequences, the N-balance method was generally most in accordance with the C pool measurements, although the SMART2 model was also quite consistent with the measurements at two chronosequences. The limit-value approach generally overestimated the soil carbon sequestration. At the intensive monitoring plots, the limit-value concept calculated the highest carbon sequestration, ranging from 160 to 978 kg ha⁻¹ year⁻¹, followed by the N-balance method which ranged from 0 to 535 kg ha⁻¹ year⁻¹. With SMART2 we calculated the lowest carbon sequestration from −30 to 254 kg ha⁻¹ year⁻¹. All the three approaches found lower carbon sequestration at a latitude from 60 to 70° compared to latitudes from 40 to 50 and from 50 to 60. Considering the validation of the three approaches, the range in results from both the N-balance method and SMART2 model seems most appropriate.     

Variation in Pathogenicity Among South African Isolates of Phytophthora cinnamomi

Phytophthora cinnamomi isolates from South Africa were evaluated for differences in growth rate in vitro and levels of pathogenicity towards Eucalyptus smithii in the field. Inoculations were conducted in the field in summer and winter in two subsequent years at two locations in South Africa using 59 P. cinnamomi isolates. The isolates differed significantly in growth rate in vitro, as well as in levels of pathogenicity to E. smithii in the field. Growth rate in vitro was significantly influenced by interactions with culture age, geographic origin and genetic background as determined using isozymes. Levels of pathogenicity in the field were influenced by season of inoculation and average minimum temperatures at trial sites. The host from which P. cinnamomi isolates were originally obtained did not significantly affect levels of pathogenicity in the field. Culture age had a significant negative effect on growth rate in vitro and pathogenicity in the field. Significant differences in levels of pathogenicity could be found for different multilocus isozyme genotypes. Geographic origin and mating type of P. cinnamomi isolates had no significant effect on levels of pathogenicity in the field. A positive correlation was found between growth rate in vitro and levels of pathogenicity in the field. Levels of variation for pathogenicity within A1 mating type isolates were significantly lower than for A2 mating type isolates. Results of this study provide valuable information on selection of P. cinnamomi isolates for future resistance/tolerance screening assays of Eucalyptus germplasm in South Africa.     

Investigation of the expression and localization of glucose transporter 4 and fatty acid translocase/CD36 in equine skeletal muscle

OBJECTIVE: To investigate the expression and localization of glucose transporter 4 (GLUT4) and fatty acid translocase (FAT/CD36) in equine skeletal muscle. SAMPLE POPULATION: Muscle biopsy specimens obtained from 5 healthy Dutch Warmblood horses. PROCEDURES: Percutaneous biopsy specimens were obtained from the vastus lateralis, pectoralis descendens, and triceps brachii muscles. Cryosections were stained with combinations of GLUT4 and myosin heavy chain (MHC) specific antibodies or FAT/CD36 and MHC antibodies to assess the fiber specific expression of GLUT4 and FAT/CD36 in equine skeletal muscle via indirect immunofluorescent microscopy. RESULTS: Immunofluorescent staining revealed that GLUT4 was predominantly expressed in the cytosol of fast type 2B fibers of equine skeletal muscle, although several type 1 fibers in the vastus lateralis muscle were positive for GLUT4. In all muscle fibers examined microscopically, FAT/CD36 was strongly expressed in the sarcolemma and capillaries. Type 1 muscle fibers also expressed small intracellular amounts of FAT/CD36, but no intracellular FAT/CD36 expression was detected in type 2 fibers. CONCLUSIONS AND CLINICAL RELEVANCE: In equine skeletal muscle, GLUT4 and FAT/CD36 are expressed in a fiber type selective manner.     

Immunohistochemical identification and fiber type specific localization of protein kinase C isoforms in equine skeletal muscle

OBJECTIVE: To investigate whether protein kinase C (PKC) isoforms are expressed in equine skeletal muscle and determine their distribution in various types of fibers by use of immunofluorescence microscopy. ANIMALS: 5 healthy adult Dutch Warmblood horses. PROCEDURE: In each horse, 2 biopsy specimens were obtained from the vastus lateralis muscle. Cryosections of equine muscle were stained with PKC isoform (alpha, beta1, beta2, delta, epsilon, or zeta)-specific polyclonal antibodies and examined by use of a fluorescence microscope. Homogenized muscle samples were evaluated via western blot analysis. RESULTS: The PKC alpha, beta1, beta2, delta, epsilon, and zeta isoforms were localized within the fibers of equine skeletal muscle. In addition, PKC alpha and beta2 were detected near or in the plasma membrane of muscle cells. For some PKC isoforms, distribution was specific for fiber type. Staining of cell membranes for PKC alpha was observed predominantly in fibers that reacted positively with myosin heavy chain (MHC)-IIa; PKC delta and epsilon staining were more pronounced in MHC-I-positive fibers. In contrast, MHC-I negative fibers contained more PKC zeta than MHC-I-positive fibers. Distribution of PKC beta1 was equal among the different fiber types. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that PKC isoforms are expressed in equine skeletal muscle in a fiber type-specific manner. Therefore, the involvement of PKC isoforms in signal transduction in equine skeletal muscle might be dependent on fiber type.     

Comparison of two-dimensional and three-dimensional systems for kinematic analysis of the sagittal motion of canine hind limbs during walking

OBJECTIVE: To test the hypotheses that kinematic data of the sagittal motion of canine hind limbs during walking obtained with a 2-dimensional (2-D) system correlate well with those obtained with a 3-dimensional (3-D) system and that the data obtained with the 2-D system are repeatable. ANIMALS: 6 adult dogs with no evidence of lameness. PROCEDURES: Hind limb motions of 6 walking dogs were recorded via 2-D video and 3-D optoelectric systems simultaneously. Five valid trials were digitized, and 5 data sets (2-D 60 Hz, 3-D 180 Hz, 3-D sagittal 180 Hz, 3-D 60 Hz, and 3-D sagittal 60 Hz) of a complete gait cycle were created for each dog. In sagittal data sets, 3-D data were reduced to exclude coordinates for mediolateral orientation. Temporospatial parameters; angles of hip, stifle, and tarsal joints; and coefficients of variation of angular measurements of each dog were calculated for each data set. Accuracy of the 2-D analysis was determined by calculating mean absolute differences and estimating agreement between the 2-D and 3-D 180-Hz data sets. RESULTS: Values of joint angles and angular excursions measured with the 2-D system were repeatable and agreed with respective values obtained with the 3-D system. Reduction of the sampling rate had a greater impact on values of kinematic variables obtained with the 3-D system than did elimination of data on mediolateral orientation. CONCLUSIONS AND CLINICAL RELEVANCE: Kinematic analysis using a 2-D video system provided accurate and repeatable data of the sagittal angular motion of canine hind limbs during walking.     

Evaluation and Exploration of Lactic Acid Bacteria for Preservation and Extending the Shelf Life of Fruit

ABSTRACT

The bio-preservation of fruits using bacteriocinogenic lactic acid bacteria (BLAB) isolated directly from cow dung and curd was an innovative approach. The objectives of this study were to isolate and identify Bacteriocin producing LAB from various curd and cow dung samples, evaluate their antimicrobial effects of BLAB against selected fruits spoiling and pathogenic microorganisms in vitro. LAB was isolated using MRS media. The well-diffusion bioassay was used to screen for Bacteriocin-Like Inhibitory Substance (BLIS) producing LAB Salimicrobium Bacillus, Paenibacillus and Lactobacillus. BLIS producing LAB were tested against 25 fruit flora of selected fruits. These LABs were also tested against Escherichia coli, Staphylococcus aureus, Bacillus cereus, Pseudomonas aeroginosa, Proteus vulgaris, Salmonella typhi, Serritia spp, Xanthomonas campestris, and also against Aspergillus flavus, Aspergillus nigar, Fusarium, Alternaria, Saccharomyces cerevisiae using the diffusion bioassay plate method. The antagonistic activity was also studied against pathogenic fruit flora which has been isolated from fruits. These BLISs showed a wide range of antibacterial activity against tested, fruit-spoilage and fruit-borne pathogens and able to extend the shelf life of fruits. Bacteriocinogenic LAB present in curd and cow dung may have potential to be used as bio-preservatives of tested fruits.     

Congenital malformations of the lumbosacral vertebral column are common in neurologically normal French Bulldogs,English Bulldogs,and Pugs,with breed‐specific differences

Congenital vertebral malformations are common findings on diagnostic imaging of the vertebral column in “screw‐tailed” brachycephalic dogs. The aims of this study were to evaluate the prevalence and anatomical characteristics of lumbosacral congenital vertebral malformations in French Bulldogs, English Bulldogs, and Pugs presenting for problems unrelated to spinal disease, as well as possible associations with the degree of tail malformation, lumbosacral intervertebral disc herniation, or spondylosis deformans. In this retrospective cross‐sectional study, CT scans of vertebrae L6 to S3 and of the coccygeal vertebrae were reviewed for type of congenital vertebral malformations (hemivertebrae, block vertebrae, lumbosacral transitional vertebrae, and spina bifida), lumbosacral intervertebral disc herniation, lumbosacral spondylosis deformans, and degree of tail malformation. In 76 (51.0%) of the 149 included dogs (53 French Bulldogs, 37 English Bulldogs, and 59 Pugs) at least one type of congenital vertebral malformations was found, with lumbosacral transitional vertebrae being the most common (34.2%). There was a significantly higher prevalence of lumbosacral transitional vertebrae (54.2%) and lower prevalence of hemivertebrae (1.7%) in Pugs compared to English (13.5% and 24.3%, respectively) and French Bulldogs (26.4% and 32.0%, respectively). Tail malformation was significantly more severe in dogs with evidence of hemivertebrae. Congenital vertebral malformations are a common finding in the lumbosacral vertebral column of French Bulldogs, English Bulldogs, and Pugs. These anatomical variances need to be considered when interpreting diagnostic studies and when planning for neurosurgical and neurodiagnostic procedures. Furthermore, this study suggests a possible association between the degree of tail malformation and lumbosacral hemivertebrae.