Spectrophotometric assessment of peritoneal fluid haemoglobin in colic horses: an aid to selecting medical vs. surgical treatment

In a case-control study in colic horses the ability of spectrophotometric measurement of the haemoglobin concentration in the peritoneal fluid supernatant and visual assessment of the colour of peritoneal fluid supernatant to differentiate between surgical and medical treatment of colic was assessed. Based on previous studies, which have found anda association between peritoneal fluid colour and the kind of treatment required, our hypothesis was that the peritoneal fluid haemoglobin concentration would be higher in horses requiring surgical intervention than in horses amenable to medical treatment. Seventy-four horses admitted to a teaching hospital were included. Thirty-five horses were classified as requiring surgery and 39 medical treatment. Logistic regression revealed a significant (P < 0.0001) association between the haemoglobin concentration measured with the spectrophotometer and the need for surgical treatment. Odds ratio for an increase in haemoglobin concentration of 0.01 mmol/l was 6.4, which means that the odds for 'need for surgical treatment' increased when peritoneal fluid haemoglobin concentration increased. When used as a diagnostic test with a threshold of 0.01 mmol/l haemoglobin for selecting surgical vs. medical treatment, sensitivity was 80% and specificity 82%, whereas simple visual assessment had a sensitivity of only 51% and a specificity of 95%.     

Associations between maternal milk protein genotypes with preweaning calf growth traits in beef cattle

The objectives of this study were to investigate milk casein polymorphisms in dams and to determine the impacts of maternal casein genotypes on growth traits of their sucking calves. Milk samples from 433 dams of the breeds German Angus (GA) and German Simmental (GS) were typed at the milk protein loci α _s1-casein (α_s1-CN), β-casein (β-CN), α _s2-casein (α_s2-CN), and κ-casein (κ-CN) via isoelectric focusing. Associations between casein genotypes in maternal milk with growth traits of their 1,872 calves were analyzed until the age of weaning using linear mixed models, considering either genotypes of individual casein loci (model 1) or composite α _s1-β-α _s2-κ-CN genotypes within the casein cluster (model 2). Besides environmental effects such as sex, age of the dam, and calving year-season, genetic effects (breed group and maternal and paternal effects) were considered in statistical models. The composite casein genotype BBǀA2A2ǀAAǀAB (order of genes on bovine chromosome 6: α _s1-ǀβ-ǀα _s2-ǀκ-CN) was associated with greater average daily weight gains (ADG) and heavier age-adjusted weaning weights (WW) of calves (P < 0.05). The effects of composite genotypes on birth weight of calves were similar (P > 0.05; model 2). With regard to individual casein loci, greater ADG and WW were observed for calves from dams with the genotypes κ-CN BB and α _s1-CN BB, respectively (P < 0.05; model 1). Age-adjusted WW was largest for calves from dams carrying the κ-CN genotype BB (215 kg) compared with calves representing the maternal AB and AA genotypes (both 204 kg). Results from the present study suggested selectable casein genotypes due to their nutritional value of milk (value in terms of offspring performances), offering new perspectives for breeding strategies in beef cattle to improve preweaning calf performance.     

The role of agro-ecological factors and transboundary transhumance in shaping the genetic diversity in four indigenous cattle populations of Benin

The indigenous cattle population of Benin is a diverse mix of taurine and hybrid breeds shaped by diverse ecological and climatic conditions with eight agro-ecological zones (AEZ). Presumably, the taurine breeds face current endangerment due to ongoing indicine introgression following climate change and transboundary transhumance. The aim of the study was to investigate the genetic diversity and population structure of the indigenous breeds Lagune, Somba, Pabli and Borgou considering spatial agro-ecological and socio-economic factors (transhumance) based on 50k SNP and microsatellite data. Among the four sampled breeds, six genetic clusters were identified using model-free (discriminant analysis of principal components) and model-based (TESS and ADMIXTURE) methods separating taurine from hybrid breeds. Results based on an extension with publicly available historic SNP data sets from taurine and indicine West African cattle and additional outgroups provided additional insight into changes of genetic structure in the sampled breeds over time. Both taurine breeds, Somba and Lagune, showed a stable foundation but also spatially limited partial indicine introgression associated with transhumance leading to high genetic diversity. In addition, we found evidence for spatial diversity and changes in genetic structure over time in the Borgou breed in comparison of our samples with the historic samples which could be explained by potential continuous indicine introgression into the Borgou breed in two sample regions. Results for the Pabli breed do not conclusively point to full absorbance by the Borgou in comparison with all available Borgou samples. Further research is needed in this regard.     

Oligonucleotide probes for DNA fingerprinting in horses

SUMMARY: 10 different oligonucleotide probes were evaluated for DNA fingerprinting in horses. Five probes were able to detect polymorphic bands. The probes (GT)(8) , (GTG)(5) and (GGAT)(4) are most informative for individual identification and were used to analyze a population of Hannoveranian horses. The probability that two individuals have the same DNA fingerprint pattern is 1.2 × 10(-8) , 5.2 × 10(-10) and 1.5 × 10(-7) respectively. Using a combination of the three probes, paternity tests were performed with exclusion probabilities between 0.08% and 4%. ZUSAMMENFASSUNG: Oligonukleotide-Sonden für DNS-Fingerprints von Pferden Zur Darstellung von DNA-Fingerprints beim Pferd wurden zehn verschiedene Oligonukleotid-Sonden verglichen. Mit fünf Sonden konnten polymorphe Banden nachgewiesen werden. Die Sonden (GT)(8) , (GTG)(5) und (GGAT)(4) besa?en die gr??te Informativit?t für den Identit?tsnachweis und wurden für die Analyse einer Population von Hannoverschen Pferden benutzt. Die Wahrscheinlichkeit, da? zwei Individuen dieselben Fingerprint-Muster aufweisen, liegt bei 1,2 × 10(-8) , 5,2 × 10(-10) bzw. 1,5 × 10(-7) . Bei Verwendung einer Kombination der drei Sonden wurden Vaterschaftskontrollen mit Ausschlu?wahrscheinlichkeiten zwischen 0,08% und 4% erreicht.     

Refined mapping of quantitative trait loci for somatic cell score on BTA02 in the German Holstein

The aim of this study was to more precisely map a previously reported quantitative trait locus (QTL) affecting somatic cell score on Bos taurus autosome 2 by increasing the number of markers fourfold, analysing more families and exploiting within‐population linkage disequilibrium (LD). A granddaughter design of 10 German Holstein grandsire families with 1121 progeny tested sons was used. Twenty‐six markers with an average marker spacing of 3.14 cM were genotyped along 81.6 cM. Linkage analysis (LA) was performed using variance‐component methodology. The incorporation of LD was first done using variance‐component methods followed by regression on marker alleles. LA revealed genome‐wide significance (LOD > 3) at 15 contiguous marker‐intervals, with the maximum test‐statistic between DIK2862 and BMS778 and a 1‐lod drop‐off interval of 38 cM. While the variance‐component methods could not detect any LD, two individual markers with a significant effect (ILSTS098, p < 0.05; BMS778, p < 0.01) were found by regression analysis. Compared with previous results QTL‐localisation was substantially narrowed; further fine‐mapping should focus on the close vicinity of BMS778.