fi - May 2006

the invasiveness of coccidia, decreased the incidence of coccidia-related gut lesions, attenuated the decrease in gut villus height associated with coccidiosis, and enhanced the destruction of coccidia by the immune cells of the gut (Augustine et al, 1997; Augustine and Danforth, 1999; Kettunen et al, 2001c; Klasing et al, 2002).

Thus, the positive effects of betaine on gut integrity and health indicate that it could play a role in decreasing the susceptibility to heat-induced gut damage of livestock fed diets containing high levels of processed grains.

Prevention of
heat-induced gut damage

The reduction in blood flow to the gut that accompanies heat stress damages cells because of an insufficient supply of energy. In cattle, half the energy consumption of the intestines is used on ion-pumps that maintain osmotic balance. Research has shown that betaine results in a 64% sparing of ion-pump activity (Moeckel et al, 2002). It is thus possible that betaine supplementation would enable gut cells to cope to a greater extent with the reduction in energy supply that accompanies heat stress. In the absence of heat stress, the energy-sparing effect of betaine on gut cells is equivalent to about 8% of whole-body energy requirements, which is in agreement with other research, which showed that the energy requirements of betaine-supplemented pigs were reduced by 5.5% (Schrama et al, 2003).

Many of the harmful effects of endotoxin are mediated by tumor necrosis factor- and nitric oxide. Researchers have reported that betaine decreased liver damage caused by endotoxin and reduced the secretion of tumor necrosis factor- by 38% and that of nitric oxide by 21% (Kim and Kim, 2002). A similar suppression of tumor necrosis factor- by a mixture of betaine and taurine was observed when liver cells were exposed to an osmotic challenge (Wettstein and Häussinger, 1997). These results suggest that betaine not only protects against gut damage, but enables the liver to cope when gut damage occurs.

In the new paradigm, the gut is a critical mediator of the adverse effects of heat stress and heat stroke, which presents exciting new opportunities for the livestock industry. Of these, dietary betaine supplementation has the potential not only to help prevent heat-induced damage to the gut, but to increase resilience against heat stress by decreasing diet-induced damage to the gut.

▼

A full list of references is available from Danisco Animal Nutrition. Please contact info. animalnutrition@danisco.com, using the subject line ‘Fighting heat stress’.

Nutreco Aquaculture Research Centre (ARC) is the central R&D unit for Nutreco’s global fish feed company Skretting. Nutreco ARC’s main objective is to provide research and technical support regarding fish feed for salmonids and marine species. ARC core competencies are within fish nutrition, feed raw materials, feed safety & quality and feed manufacturing processes. Its facilities include a research station with hatchery, land based tanks and sea cage trial facilities, a pilot plant for feed production and a well-equipped modern chemical laboratory.

Based in Stavanger, Norway, Nutreco ARC has 60 highly skilled employees from 8 different countries, many of them with postgraduate qualifications. In addition Nutreco ARC co-operates with universities

and research institutions worldwide.

Nutritionist

Nutreco ARC is seeking a nutritionist to work within the technical area of

planning and interpretation of R&D work in fish nutrition; operational maintenance of central feed optimisation. The working location is Stavanger, Norway.

Required skills and knowledge: Ph.D. or equivalent commercial experience in animal nutrition.

The positions offer the opportunity to:

• join an established team of 20 researchers

• work in an international environment

• use of own research facilities

• play an important role in identifying, testing and implementing new concepts

• interact with, and travel to, other company sites throughout the world

• operate in a progressive, competitive and highly innovative environment

Applicants shall combine a high level in nutritional understanding with an innovative mindset and good skills to interact and communicate with people.