The growing global livestock production is moving away from antibiotic growth promoters and coccidiostats, means that the industry will therefore face new challenges impacting gut health. As a consequence, gut health management has become a key focus in the livestock production.
The role of betaine and its physiological functions
Over the last years, the use of betaine in animal feed diets has moved from selective utilization, to that of a core ingredient in key feed formulations for poultry, swine and even ruminants. The increased use of betaine in animal diets has been driven by producer demands, to counter performance challenges under heat stress conditions especially in poultry, as a methionine/choline sparing tool, to further improve carcass yield and quality in broilers. The benefits are the result of betaine’s role in two main physiological functions: its osmolyte property and acting as a methyl group donor.
Both functions of betaine play a key role, particularly when animals are under challenging conditions, which include dietary changes, heat stress, temperature stress (fluctuation between the day and night temperatures) and pathogenic challenges (mainly coccidiosis) often with wet litter as a consequence. This in turn can lead to further severe complications like respiratory disease or pododermatitis. The fact is, that the higher the challenges, the higher the demand is on methyl groups. In such conditions, the mineral and water balance might be disturbed and the cell wall integrity potentially damaged.
Energy is one of the major dietary cost factors in poultry production and osmoregulatory responses are highly energy consuming processes. Betaine, being involved in the energy metabolism, can reduce the energy required for the osmoregulation. Under normal conditions, the energy saved can be used for increased animal performance and improved carcass quality. Whilst in challenged conditions, it can reduce digestive disorders and lower mortality, thereby better production efficiency.
Choosing the right source
Nowadays, there are many products to choose from, both natural and synthetic. Thus, the question for many feed producers is how best to proceed, by choosing a naturally sourced product including extraction from sugar beets, or a chemical synthetic product. However, nutritionists may also need to consider the impact of the Cl¯ on the DEB (Dietary Electrolyte Balance) especially in heat stress conditions. Higher temperatures require higher DEB values hence ingredient selection and formulations strategies to limit Cl¯ should be considered. Besides the content on inorganic ions, synthetic products betaine-hydrochloride and choline-chloride, as well as synthetic betaine anhydrous, may contain higher Trimethylamine (TMA) levels (up to 70 times higher than naturally sourced betaine), which are highly corrosive in the nature. Particularly high TMA levels, can affect the intestinal mucosa, leading to reduced nutrient utilization and can cause also respiratory discomfort. Any discomfort will lead to less feed intake and less performance. At lower concentrations, TMA can have a negative influence on the quality of end-products e.g. fishy eggs or fishy tainted meat.
In line with the above mentioned, in 2012, the European Food Safety Authority classified TMA’s as being “corrosive to the eye and strongly corrosive to the skin and known irritant to the respiratory tract” and there were setting maximum safe levels for trimethylamine and its salt. (Pls. see the EFSA Journal 2012;10 the “Scientific Opinion on the safety and efficacy of aliphatic and aromatic amines: 3-methylbutylamine, trimethylamine and its salt”.)
Natural sources of Betaine are available on the market in either powder or liquid forms. AGRANA, an Austrian based company that converts agricultural raw materials into high-quality foods and numerous industrial intermediate products, has been extracting Betaine sourced from sugar beet for many years. In 2015 the company has decided to upgrade and expand the production processes to increase the quantities and purity of the betaine extracted from the sugar molasses, making a new source of natural Betaine available to the market under the brand name ActiBeet®.
To confirm the efficacy of this new natural and GMO-free source of Betaine from AGRANA, a trial was conducted in Thailand, in cooperation with Mr. Saksit Srinongkote (animal research consultant). The results underline the effect of natural betaine on the carcass quality of broilers in challenged conditions and the effect on the litter quality in broiler production.
Four hundred newly hatched male broiler chicks (Ross 308) were randomly allocated to five treatments with eight replications, using 10 male birds in a pen as an experimental unit. A practical corn-soybean meal diet was formulated as the positive control (PC) diet for each growing phase. A negative control (NC) diet, with 100 kcal ME/kg lower than that of the PC diet, was formulated for each growing phase. During the test, the methyl group donor products were supplemented in the NC diet, at the same level of activity: 1000 mg/kg of complete feed, as shown in the treatment design below:
- Diet 1: Positive control (PC) practical corn-SBM diet, according to Ross 308 nutritional guideline,
- Diet 2: Negative control (NC) as diet 1, but with lower ME by 100 kcal/kg,
- Diet 3: NC + Test betaine product 1 BET1 – ActiBeet® L (liquid, natural source of betaine produced by AGRANA) 40%,
- Diet 4: NC + Test betaine product 2 BET2 – crystallized natural betaine product 96%,
- Diet 5: NC + Test product 3 CHOL3 – choline chloride 50%, synthetic product.
The test products were added to the experimental feed before pelletizing. All diets were pelletized under a conditioning temperature of 80°C. The birds were exposed to an ambient temperature of about 35°C by setting the water to run through the cooling pads only when the house temperature increased to above 35°C. Bad or unclean conditions were also provided by using 50%/50% used/new litter. Dirty litter should facilitate mild GIT disorders in order to observe the effect of betaine under such conditions. Per pen, bodyweight and feed consumption were measured for growth, feed intake and FCR calculation. The trial was conducted over 38 days. Following bodyweight measurement on day 38, two birds from each pen were selected and slaughtered for carcass measurements (breast meat yield, thigh yield, drumstick and abdominal fat). On day 38, the litter in each pen was assessed by visual scoring. Additionally, a litter sample of about 1 kg was collected from each pen for litter moisture content evaluation (80°C for 24 hours). The data was subjected to analysis of variance as a randomised complete block design.
Strong results even in challenging conditions
The results found that supplementation of methyl donor products did not significantly affect all of the carcass traits. Improvement in breast meat yield and lower abdominal fat content were observed by supplementing natural betaine products (Table 1).
All methyl donor products improved the litter quality by reducing the score of visual litter assessment and the litter’s moisture content; better results were recorded by supplementation of the natural BET test products (Table 2):
It is important to mention that considering the overall period (0-38 days), birds fed NC diet had significantly lower BWG and higher FCR than those fed PC diet. The supplementation of all test products improved BWG and FCR of birds fed the NC diets (diets 3 -5). Higher breast meat yield with lower abdominal fat and less moisture in the litter were shown in the natural BET groups.
Gut health and litter quality are directly linked. Any challenge to the gut can often cause diarrhea, resulting in increased nutrient and moisture excretion into the litter and litter quality, which not only has economic implications but is also relevant to bird welfare.
Based on litter score data, the positive effect of natural betaine in managing gut health is evident. As a multifunctional nutrient, betaine is a proven nutritional aid in coping with the manifold challenges that broiler production faces.
References are available on request.