Benefits of exercise on insulin sensitivity

Unless dietary restriction below maintenance energy requirements is also employed, moderate exercise on its own is not enough to counter insulin resistance in obese or overweight horses, according to Dr Rebecca Carter and colleagues at Virginia Tech.

They examined the effects of exercise training alone on overweight or obese, insulin-resistant horses. Feed intake was limited during the study to 100% of maintenance energy requirements.

Eight horses, all either overweight or obese, followed a low intensity exercise program for 4 weeks followed by higher intensity exercise for a further 4 weeks. Finally they had two weeks without exercise (detraining). A control group of four horses received no structured exercise.

The horses’ body weight fell by 2% following the low intensity exercise and by a similar amount after the 4 weeks of higher intensity exercise. However, about half of the body weight lost during the exercise stages was put back on again within the two weeks of detraining with no exercise.

The researchers found no significant difference in glucose or fat metabolism or insulin sensitivity between the exercised and control groups throughout the study.

Dr Carter comments "even though our study did not show long-term training effects of exercise, there still are probably improvements in insulin sensitivity during and shortly after an exercise session. Therefore, ROUTINE exercise (every day) may be beneficial for improving insulin sensitivity."

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Another cloning milestone has been reached by researchers at Texas A&M University with the successful birth of a foal produced using oocytes from a live mare.

Mouse, was born May 5, 2010. The efforts of his owner, Kit Knotts, to find a horse that had the same qualities as her prized Lippizaner stallion Marc, (Pluto III Marcells) led her to Texas A&M University and equine reproduction expert Dr Katrin Hinrichs.

"We have worked on this clone for about two years," said Hinrichs, a professor in the Department of Veterinary Physiology and Pharmacology.  "This is actually our first foal produced using oocytes, or egg cells, from live mares."  She explains that using oocytes from live mares made the process difficult as they had very few oocytes to work with at any one time.

Minnie, the surrogate mare, began to show signs of an early delivery, and was taken to the University of Florida College of Veterinary Medicine for observation and intervention. That’s where Mouse arrived and was cared for by a team of neonatal experts that helped make sure he would make it through this critical time.

Because of the risk of complications and problems in the period just after birth, Dr Hinrichs’ team recommends that foals derived by cloning should be treated as high-risk neonates, and their birth should be closely supervised. Facilities for intensive care should be available in case they are needed.

To read more about the problems faced by cloned foals go to www.equinescienceupdate.co.uk/clone3.htm

Lavender Foal Syndrome

Researchers have identified the genetic mutation responsible for Lavender Foal Syndrome. Lavender Foal Syndrome (LFS), also known as Coat Color Dilution Lethal (CCDL), is a fatal disease of newborn Arabian foals, particularly in those of Egyptian Arabian breeding.

The condition gets its name from the abnormal coat colour with which most affected foals are born, which has been described as silver sheen, lavender, pale chestnut or pale, dull pinkish grey.

Signs shown by affected foals include seizures, nystagmus (involuntary movement of the eyeballs), limb rigidity, paddling movements, and opisthotonus (hyperextension of the head, neck, and spine). The mare often has difficulty giving birth.

A team of scientists from Cornell University and the Maxwell H Gluck Equine Research Center have found that Lavender Foal Syndrome is the result of a mutation in a gene called myosin Va (MYO5A).

The myosin Va transport complex is responsible for the transfer of pigment to the keratinocytes and for transport of transmitter substances in the nerve cells. A mutation affecting the gene could easily result in interference with normal function of melanocytes (responsible for hair color) and nerve cells.

“Our results suggest that the population frequency of carriers of this deletion is 10.3% in the Egyptian Arabian” reports lead researcher Dr Samantha A. Brooks, assistant professor in the Department of Animal Science at Cornell University's College of Agriculture and Life Sciences.

“Given our estimate of the number of carriers in the population we expect that around nine LFS foals would be born in the USA each year”

For more about the research on Lavender Foal Syndrome click here.

Antibiotic resistance in equine faeces

Horses can be a source of antibiotic-resistant bacteria, presenting a threat to human health, according to a recent study.

Mohamed Ahmed, of the Department of Veterinary Microbiology and Parasitology, at Al Fatah, University, Tripoli, Libya, working with colleagues at the Liverpool Vet School, examined fecal samples collected from the University’s equine hospital and from livery yards.

They found antibiotic resistant E. coli in faeces from both locations. From a total of 264 samples, 296 isolates of antibiotic-resistant Escherichia coli were identified.

Not only were hospitalised horses more likely to have antibiotic resistant E. coli in their faeces, they were also more likely than those maintained on livery yards to carry organisms that were resistant to multiple drugs.

Nearly half (48%) of the resistant isolates from the hospital environment showed multiple drug resistance phenotypes, compared with only 12% from the livery yards.

The researchers conclude that, in the UK, horses may provide both recipients, and sources, of antibiotic resistance, MDR, and be an extensive reservoir of antimicrobial resistance genes that could pose a potential threat to human health.

For more details see:

http://www.equinescienceupdate.co.uk/aref.htm