Broiler nutrition should continue to evolve to keep up with genetic improvements. The biggest steps to take are definitely situated in the post hatch period. The initial focus on organ growth should be supported by a specialised prestarter feed.
Broiler day-old chickens have to cope with two important growth related challenges. Next to the extremely fast growth in the beginning, organ growth needs priority over muscle growth.
Daily growth of broiler chickens reaches its maximum value at the end of the growing period (more than 100 g/d). Nevertheless, relative to their own body weight, they are growing the fastest at the start of their lifetime.
Nutritional needs of chickens
In the first days, day-old chickens need to grow up to 30-35% of their own body weight. From Figure 1 it is clear that chickens have totally different nutritional needs at day 1, compared to their needs at day 10. As a consequence, a starter feed provided from day 1 until day 10-14 will be inadequate to support an optimal growth during the first days of life. Day-old chickens will benefit to a large extent from a specialised prestarter feed.
Non-domesticated birds (the finch, the woodpecker, the ringdove, etc) are altricial birds, meaning that the parents are feeding the young birds with easily digestible raw materials (worms, insects, etc). Domesticated birds on the other hand don’t have the parents to feed them (precocial), see Figure 2. Instead they are dependent on the more difficult digestible feed that we offer them (soybean meal, wheat, corn, etc). That is why during the first week the body weight of a broiler chicken is only multiplied by four, whereas the organ weight increases by a factor 10. The overall development is not focused on body weight gain, but on intestinal development. Therefore, it is important that the day-old chickens also receive a feed that is focused on this organ development.
Figure 2 – Precocial birds vs altricial birds
The focus points for a specialised prestarter
Easily digestible feed
A prestarter should be very easy to digest, in order to let the chickens gain weight in a very efficient and fast way. An experimental trial was set up where day-old chicks were fed a specialised prestarter feed versus a normal starter during a period of 3 hours after arrival in the broiler house. After these 3 hours, the chickens were withdrawn from feed and water and again 5 hours later, the gizzard was analysed.
Figure 3 clearly shows an empty stomach for the chicken fed an easily digestible prestarter. On the contrary, the stomach of the chicken fed a normal starter feed is not empty and the digestion is still ongoing. This shows that a specialised prestarter can really facilitate digestion. An easy and fast digestion will result in a higher uniformity, because the weak chickens can also digest the feed in an efficient way.
Figure 3 – Stomach emptying with a specialised prestarter (left) and a normal starter (right).
A good activity of day old chickens is essential for a good feed intake and needs a fast energy source. Activity scoring is performed by putting the chickens on their back, and measuring the time needed to return on their feet. Table 1 shows that the activity of the chickens fed with a prestarter is much better compared to the chickens fed with a control feed.
Top pellet quality
To reduce dust fractions, a minimum Pellet Durability Index (PDI) of 95% should be taken into account. At the same time the pellet needs to disintegrate easily in the mouth. When tested, 86.7% of the crops of chickens fed the specialised prestarter were nicely filled, compared to only 78.3% for the chickens fed the normal starter. This shows that chickens will start eating the specialised prestarter sooner.
In the beginning of life, the newly hatched chickens lack antioxidants like Vit E, Vit C and Se. As an extra antioxidant source, a specialised prestarter can be supplemented with natural antioxidants. As a result the antioxidant capacity of the small birds is increased, so that they can cope with stress more efficiently, now and in later stages of life.
Chicks have a weak immune system during the first days of life. In order to ensure optimal protection of the chicks, ingredients are added that kill the pathogens on the one hand and also strengthen the immune system on the other. An experimental trial in breeders resulted in a decrease in mortality after 7 days from 1.19% for the normal starter to 1.01% for the prestarter.
The new prestarter of Nuscience
Based on the above-mentioned focus points Nuscience developed a new prestarter concept. Galli Crunch already results in a significant difference in body weight at day 1. Overall results at the end (day 38) show significantly heavier chickens, raised with a significantly lower feed conversion ratio and a lower mortality rate (Table 2).
Author: Kobe Lannoo, Nuscience