Best-practice Vitamin Nutrition Strategies in Premium Poultry Production

The importance of vitamins

After World War II, poultry production was very profitable, and many people repurposed sheds or built makeshift poultry houses to raise birds. Some farmers noticed leg problems in birds housed inside all the time due to being deficient in vitamin D. As a result, sun porches were introduced to give birds time outside in the sunshine where they were able to produce their own vitamin D, preventing leg problems and improving bird performance and welfare (Figure 1).

Today, poultry producers grow birds in sophisticated, purpose-built barns with control over every aspect of the environment. The feed must supply the bird with sufficient, good-quality vitamins to promote bone strength, gut health, and overall bird welfare.

Recommended levels

When working out how much of each vitamin to add to a feed formulation, the best place to start is with the published recommendations from the breeder (e.g., Cobb or Aviagen), and with the Optimum Vitamin Nutrition recommendations from dsm-firmenich (Table 1).

(1) Added per kg air-dry feed; Local limits need to be observed; OVN levels are ranges for consideration, depending on several factors, such as husbandry conditions and health status
(2) When dietary fat is higher than 3% then add 5 mg/kg feed for each 1% dietary fat
(3) For optimum immune function increase level up to 300 mg/kg
(4) Under heat stress conditions increase level up to 200 mg/kg
(5) For optimum meat quality increase level up to 200 mg/kg
(6) Use upper level as reference for animal protein free diets and when cobalt is supplemented at very low levels or removed
(7) Recommended under heat stress condition; Use ROVIMIX® STAY-C35 for reducing loss during processing

Some nutritionists may think these recommendations are too high, but trials have shown that when they are used, feed conversion improves by one to two points. It is always important to pay attention to the units when talking about vitamins to ensure that fair comparisons are being made. In Table 1 the figures are expressed per kg of feed whereas in Table 2 they are expressed in per ton of feed.

Changes in vitamin recommendations over time

Dr. Nelson Ward of dsm-firmenich carried out a lot of work looking at the difference in vitamin recommendations over time. Some of his results are presented in Table 2.

In some cases, for example vitamin A, there has been very little change over the nearly 30-year period (+ 5%). Whereas other vitamins, for example vitamin E and biotin, have seen a much bigger change (+ 184% and + 127%, respectively).

Why do vitamin recommendations change?

There are various reasons why vitamin recommendations change over time. Firstly, growth rates have improved dramatically. In the 1970s, it took 7 weeks to grow a 4-pound/ 1.8 kilogram broiler. Today, a broiler grown for 7 weeks will be around 7.5 pounds (3.4 kilograms). On average, broiler growth rates are improving by 3 – 4% each year with a simultaneous annual improvement in feed conversion rate (FCR) of nearly 2 points. This means that less feed is being consumed for each pound of live weight gain. Therefore, the quantity of vitamins in the feed must go up to ensure requirements are met.

Improvements in feed ingredient quality have led to a reduction in the time it takes to grow a broiler to market weight. In 1995 it took 52 days to attain a slaughter weight of 5.1 pounds (2.3 kilograms), but achieving the same weight only takes 40 days in production systems today. This has an impact on vitamin intake. As FCR improves, vitamin intakes decline. In broilers and turkeys, the decrease is 0.6 – 0.8% annually.

Trials have shown that faster growing genotypes are more responsive to higher vitamin levels (Jiang et al., 2011) which could be driving the increase in vitamin supplementation.

Vitamin source will affect amount used

In some cases, e.g., vitamin D and vitamin E, the Fieldale levels look very low, but this is because the source of the vitamin must be considered. Using a smaller quantity of a higher concentration vitamin gives the nutritionist more flexibility and more space in the diet for other components while still meeting the nutritional requirements of the bird.

Feed quality

Using only high-quality feed ingredients is the foundation of achieving optimum animal performance. At Fieldale, every incoming load of feed raw materials is tested and either accepted or rejected based on various parameters. One advantage that Fieldale has compared to some of its larger competitors is that it requires smaller quantities of raw materials and can therefore be more selective with suppliers rather than having to take everything available to meet minimum quantity requirements.

In addition to the quality of the raw materials, the processing of the feed is also a key consideration. When adding a vitamin premix, it is important to ensure it is well mixed. If the same vitamin premix is used across different diets, the amount of the premix may drop to very low levels in the finisher or withdrawal feed. Achieving a consistently well-mixed feed becomes much harder at lower inclusion levels so extra care must be taken to ensure vitamins are delivered to the animal in the right quantities.

Fat quality

The quality of the fat included in the feed will have a direct impact on the fat-soluble vitamins delivered to the animal. If the quality of the fat is poor, the vitamins will pass straight through the animal without being used.

Birds being grown for the commodity chicken market will have feed formulated using very different ingredients compared to birds being raised for the premium market. Animal fats are much cheaper than vegetable oils so are the natural choice if feed cost is the main influencing factor, but animal fats tend to contain higher levels of insolubles and peroxide which may have anti-nutritional effects.

Additional benefits of vitamin supplementation

There are many additional benefits to using vitamins in broiler diets, over and above performance and animal welfare. Vitamin E is a known antioxidant which improves product stability, resulting in a longer product shelf life. And at Fieldale, vitamin E is used as part of a larger program to improve the taste of the chicken. Vitamins can also be used to mitigate against conditions such as woody breast, foot pad lesions, hock burns and breast blisters. In the US, chicken feet can retail at US$0.90 per pound. By comparison, breast meat is retailing at US$1.15 per poun d, so reducing foot pad lesions and being able to sell more of the bird makes a big difference in the economic performance of the flock.

Conclusions

Vitamins are an extremely important part of the diet and need to be monitored carefully. If animals are vitamin deficient, this can lead to welfare issues such as leg problems, and quality issues such as woody breast. Using the published vitamin recommendations, either from breeders or from dsm-firmenich, is a good place to start when formulating diets, but various factors should be considered which will affect the quantity of vitamins that are included in the diet. Ingredient quality, source of the vitamin, target market and animal genotype all need to be considered.