The improved capacity of the birds to control their body temperature can be explained by the increased water retention when betaine is supplied, which might increase peripheral blood flow and evaporation, reducing heat stress. Alleviating heat stress symptoms is not only beneficial for animal welfare, it leads to better performance and decreased mortality.
Improving digestion, absorption and nutrient utilization
One of the tissues where betaine establishes its beneficial effects during heat stress is the gut tissue. Dietary betaine increases the betaine concentration in the intestinal epithelium, stimulating the protection of the intestinal cells against osmotic disturbances. The osmoprotective effects of intracellular betaine preserve the important functions of the intestinal cells, such as enzyme production and nutrient absorption. Because betaine also stimulates intestinal cells to continue proliferation, a better conservation of the mucosal structure of the gut (crypts and villi) can be observed.
It is well known that the process of nutrient digestion and absorption depends on an intact gut epithelium and that this gut integrity is impaired during heat stress. The supplementation of betaine reduces the negative effects of heat stress on the gut and improves the digestibility of nutrients. When feed intake is reduced, an optimal utilization of the nutrients that are consumed is extremely important to keep up performance.
Results on production
Plenty of studies describe the positive results of betaine supplementation on the performance of poultry (broilers, laying hens, quails and turkeys). Many of these studies were done in environments with high temperatures, indicating the assistance of betaine in alleviating heat stress.
In broilers, increased weight gain, enhanced feed intake, improved feed conversion, a higher breast muscle yield and reduced abdominal fat weight are observed. In layers and breeders, betaine counteracts performance losses induced by heat stress. Egg production increases up to 23.6% and there’s also an improvement of egg quality.
Moreover, a reduction of fatty liver problems and for breeders beneficial effects on reproduction, e.g. increased viability and motility of spermatozoa and improved hatchability, are resulting benefits.
The multiple functions of betaine can improve poultry tolerance to heat stress. Dietary application of betaine hydrochloride or betaine anhydrous, in dosages from 0.5 to 2 kg/ton, is an efficient tool as part of a strategy to counter the negative effects of heat stress in poultry production.