Arcangelo Gentile

Investigations of D-lactate metabolism and the clinical signs of D-lactataemia in calves

Five clinically healthy calves received an intravenous injection of 25 g sodium D-lactate (223 mmol) in 100 ml sterile water and five control calves were given the same volume of 0·9 per cent sodium chloride. Two clinical examiners who were blinded to the status (test or control) of the calves observed that between eight and 40 minutes after the injections the calves that had received sodium-D-lactate could be distinguished with certainty from the control calves on the basis of their clinical signs, for example, an impaired palpebral reflex, somnolence and a staggering gait. One-compartment and two-compartment analyses of the changes in the plasma concentration of D-lactate, and its renal clearance, indicated that the calves metabolised considerable amounts of D-lactate.

Congenital syndactyly in cattle: four novel mutations in the low density lipoprotein receptor-related protein 4 gene (LRP4).

BackgroundIsolated syndactyly in cattle, also known as mulefoot, is inherited as an autosomal recessive trait with variable penetrance in different cattle breeds. Recently, two independent mutations in the bovine LRP4 gene have been reported as the primary cause of syndactyly in the Holstein and Angus cattle breeds.ResultsWe confirmed the previously described LRP4 exon 33 two nucleotide substitution in most of the affected Holstein calves and revealed additional evidence for allelic heterogeneity by the identification of four new LRP4 non-synonymous point mutations co-segregating in Holstein, German Simmental and Simmental-Charolais families.ConclusionWe confirmed a significant role of LRP4 mutations in the pathogenesis of congenital syndactyly in cattle. The newly detected missense mutations in the LRP4 gene represent independent mutations affecting different conserved protein domains. However, the four newly described LRP4 mutations do still not explain all analyzed cases of syndactyly.

Identification of the Bovine Arachnomelia Mutation by Massively Parallel Sequencing Implicates Sulfite Oxidase (SUOX) in Bone Development

Arachnomelia is a monogenic recessive defect of skeletal development in cattle. The causative mutation was previously mapped to a ∼7 Mb interval on chromosome 5. Here we show that array-based sequence capture and massively parallel sequencing technology, combined with the typical family structure in livestock populations, facilitates the identification of the causative mutation. We re-sequenced the entire critical interval in a healthy partially inbred cow carrying one copy of the critical chromosome segment in its ancestral state and one copy of the same segment with the arachnomelia mutation, and we detected a single heterozygous position. The genetic makeup of several partially inbred cattle provides extremely strong support for the causality of this mutation. The mutation represents a single base insertion leading to a premature stop codon in the coding sequence of the SUOX gene and is perfectly associated with the arachnomelia phenotype. Our findings suggest an important role for sulfite oxidase in bone development.

Identification of a missense mutation in the bovine ATP2A1 gene in congenital pseudomyotonia of Chianina cattle: An animal model of human Brody disease

Congenital pseudomyotonia in Chianina cattle is a muscle function disorder very similar to that of Brody disease in humans. Mutations in the human ATP2A1 gene, encoding SERCA1, cause Brody myopathy. The analysis of the collected Chianina pedigree data suggested monogenic autosomal recessive inheritance and revealed that all 17 affected individuals traced back to a single founder. A deficiency of SERCA1 function in skeletal muscle of pseudomyotonia affected Chianina cattle was observed as SERCA1 activity in affected animals was decreased by about 70%. Linkage analysis showed that the mutation was located in the ATP2A1 gene region on BTA25 and subsequent mutation analysis of the ATP2A1 exons revealed a perfectly associated missense mutation in exon 6 (c.491G>A) leading to a p.Arg164His substitution. Arg164 represents a functionally important and strongly conserved residue of SERCA1. This study provides a suitable large animal model for human Brody disease.

Determination of D-lactate in calf serum samples – an automated enzymatic assay

Since recent research has shown that D-lactataemia is obviously not an unusual problem in calves, determination of this metabolite may have considerable clinical significance. In analogy to the routinely used L-lactate assay, a stereospecific enzymatic assay of D-lactate was automated on a Hitachi Automatic Analyzer 911. As the method described does not require deproteinisation, and amounts of reagents are small, the determination is inexpensive and not labour-intensive. The method proved to be both accurate and reliable, with a limit of linearity of 16 mmol/l. A reference range was established using serum samples from 150 clinically healthy Simmental calves of both sexes, up to 3 weeks old, from 48 dairy farms in southern Germany. An upper limit of the reference range (95th percentile) of 3.96 mmol/l was found.

Diagnosis of bovine besnoitiosis in a bull born in Italy.

BOVINE besnoitiosis is a parasitic disease of cattle caused by the cyst-forming coccidium Besnoitia besnoiti . The disease has a significant economic impact due to adverse effects on male fertility, reduction of slaughter weight, and a mortality of up to 10 per cent. Knowledge on transmission routes

Deletion in the EVC2 Gene Causes Chondrodysplastic Dwarfism in Tyrolean Grey Cattle

During the summer of 2013 seven Italian Tyrolean Grey calves were born with abnormally short limbs. Detailed clinical and pathological examination revealed similarities to chondrodysplastic dwarfism. Pedigree analysis showed a common founder, assuming autosomal monogenic recessive transmission of the defective allele. A positional cloning approach combining genome wide association and homozygosity mapping identified a single 1.6 Mb genomic region on BTA 6 that was associated with the disease. Whole genome re-sequencing of an affected calf revealed a single candidate causal mutation in the Ellis van Creveld syndrome 2 (EVC2) gene. This gene is known to be associated with chondrodysplastic dwarfism in Japanese Brown cattle, and dwarfism, abnormal nails and teeth, and dysostosis in humans with Ellis-van Creveld syndrome. Sanger sequencing confirmed the presence of a 2 bp deletion in exon 19 (c.2993_2994ACdel) that led to a premature stop codon in the coding sequence of bovine EVC2, and was concordant with the recessive pattern of inheritance in affected and carrier animals. This loss of function mutation confirms the important role of EVC2 in bone development. Genetic testing can now be used to eliminate this form of chondrodysplastic dwarfism from Tyrolean Grey cattle.

Experimentally Induced Systemic Hyperchloremic Acidosis in Calves

BACKGROUND Among the various metabolic disturbances occurring in calves affected by neonatal diarrhea or ruminal acidosis, acidemia constitutes an important condition requiring specific therapy. Although various attempts have been made to estimate the degree of metabolic acidosis on the basis of clinical signs alone, some doubts have been raised regarding the accuracy and predictive value of the clinical variables suggested. HYPOTHESIS The induction of metabolic acidosis in healthy calves via the infusion of hydrochloric acid (HCl) will lead to a clinical picture similar to that seen in neonatal calves with diarrhea or ruminal acidosis. ANIMALS The study was carried out on 15 Holstein male calves between 5 and 19 days of age. METHODS Hyperchloremic metabolic acidosis was induced over a period of 80 minutes by an IV infusion of 4,000 mL of 0.9% NaCl solution containing 400 mM HCl. RESULTS Acidemia occurred rapidly and increased constantly up to a maximum value, which was reached in all calves by the end of the administration and amounted to a 22.4 mM/L mean base deficit (range from 17.0 to 33.1 mM/L). Despite the relatively severe acute acid-base imbalance during the entire observation period, no calves showed any clinical signs or depressed appetite. CONCLUSIONS AND CLINICAL IMPORTANCE Factors other than a disturbance of the acid-base balance should be considered to be primarily responsible for the clinical picture in calves affected by diarrhea or ruminal acidosis.

Congenital pseudomyotonia in Chianina cattle

A MUSCLE function disorder was observed in 11 Chianina cattle (six males and five females), and was brought to the attention of the authors because of difficulties in locomotion that had been present since birth. Clinical observations of these animals began during the first month of life and were

d-Lactic Acidosis in Neonatal Ruminants

Metabolic acidosis in calves with neonatal diarrhea was believed to be mainly caused by the loss of bicarbonate via the intestines or the formation of L-lactate during anaerobic glycolysis after tissue hypoperfusion in dehydrated calves. Because D-lactate was not considered to be of interest in human or veterinary medicine, routine diagnostic methods targeted the detection of L-lactate only. The development of stereospecific assays for the measurement of D-lactate facilitated research. This article summarizes the available information on D-lactic metabolic acidosis in neonatal ruminants.