Published on June 23, 2022
Nutritional management of SASSO broiler breeders
In this article, we are looking at the nutritional management during a new growth period of the hens. How to take into account the new feed requirements, while putting the birds in the best conditions for production.
In the previous article, we outlined the three phases of growth of future breeding pullets and their challenges and targets: a phase of development of the organs of the immune system, the skeleton, and the muscle mass, a second phase of maintenance and finally a phase of preparation for laying. We have tried to emphasize the importance of this rearing period which will allow the animals to express or not their genetic potential for laying.
This time we will focus on the production period by discussing the key steps and rules to be respected.
During the pre-lay phase, which starts at about 16 weeks of age, we need to allow the future breeder pullet to develop her reproductive system, to start storing calcium in the medullary bone and finally to develop a small fat reserve necessary for the laying marathon that follows. This phase is crucial for the entry in laying and ensures a good peak and a good persistence behind.
We can estimate that from this pre-lay phase, the pullet has other needs than her own maintenance needs. The development of the ovarian cluster requires an additional protein intake and a higher water consumption. This feed intake must be relatively controlled to avoid over-fattening of the pullet just before it starts to lay, which can have negative long-term repercussions. Let us remember here that laying and meat yield performances are negatively correlated traits. A broiler will never be a good breeder.
Laying phase start
We consider that the laying phase starts at the 0.5% of the flock. At this moment, it is necessary to start accompanying the hens to ensure a good production. This accompaniment is first done with a feed stimulation. As mentioned before, the hen's needs are now maintenance and production. The hen must continue to grow until it is about 30 weeks old, while at the same time producing a large number of hatching eggs throughout its production cycle.
At this stage, and to stimulate correctly with the feed, it is important to look at different criteria: the body weight gain of the hens, the daily evolution of the laying and finally the evolution of the egg’s weight. It is therefore very important to continue to weigh a representative sample of hens each week as they begin to lay, and to autopsy the dead ones to observe the state of fattening and the development of the flock.
The feed stimulation will depend on our strategy and needs. As we have seen in a previous article, the speed of feed stimulation has a direct impact on the increase in lay percentage as well as on the increase in the hatching eggs size. Thus, a fast evolution of the daily ration leads to a faster increase in egg laying and offers the possibility to have settable eggs (>50g) quicker. The consequences are generally a lower peak of lay and a lower persistency. Remember that a hen lays an egg mass, not a number of eggs. Larger eggs throughout the production period will therefore have a negative impact on the total number of hatching eggs at the end of the flock. Furthermore, the consequences on the hen can be equally negative: a very rapid feed stimulation can lead to sudden liver stress and early fattening if not controlled. On the other hand, a too slow stimulation will delay the peak of lay and can also have negative consequences on the performances. Indeed, if the hen is not sufficiently accompanied, she will be forced to draw on her reserves, which are then limited.
We advise, just before the start of lay, to supplement the hens with a hepato-protector in the feed to allow the liver and the kidneys to drain as much as possible just before their stimulation.
Thus, it is important to keep monitoring the body weight gain of the hens during the laying period. A too important body weight gain (with a ADG higher than the ADG just before the laying period) means a too high quantity of feed distributed with a risk of fattening. If the hen does not gain weight (or loses weight), the amount of feed distributed might be too low, which does not allow the hen to cover its maintenance and production needs.
We would like to focus on this body weight gain during the laying period because it is a risk for fattening on broiler strains. The management of our SASSO hens is closer to the management of broiler breeders than to layers. Unlike layers, who tend to put all their nutritional intake in the egg, our SASSO hens risk expressing their yield and fattening potential if the quantity ingested as well as the protein and energy intake are too high in relation to production needs.
This is why it is strongly recommended to approach our hens with broiler breeder feed formulas as soon as the first eggs are laid. While lysine (affecting peak laying and growth) and methionine (affecting egg size, coupled with linoleic acid) levels, as well as Calcium will be slightly lower than layer levels (max < 7%), the difference will be in crude protein where the gap can be about 15% lower or more for broiler breeders (~15% crude protein on a broiler breeder first lay vs. 17% for a layer formula) Here, we underline the fact that a surplus of proteins will not have any positive consequence on egg production, quite the contrary.
At the laying peak
A question that often comes up is: At what age should we reach the peak of the feed intake and what is that feed intake? Following what we have just seen, the answer is simple but also complicated. Simple, because we know that once the hens no longer have any new production needs, it is not necessary to continue to accompany the hens, at the risk of fattening them for nothing.
On average, we can estimate that a batch will evolve by 5% of lay per day. It is also known that it takes about 1 week for the follicle that starts to develop to become an egg. Thus, 5% of lay/day in one week, corresponds in reality to 35% (5%*7 days) of laying evolution. If the peak is reached around 95% of laying, we can estimate that in reality, when the batch is at 60% (95% - 35%) of laying, it is already at its peak. Therefore, it is essential to reach the peak of feed intake as soon as the hens have reached 60%. The surplus feed at this level will not be used for hatching egg production.
But the question is also complicated, because it is difficult to give a feed intake standard. As we said, it will strongly depend on the formula used, the fattening state of the hens as well as the environment (is it a hot and dry, hot and humid, cold and dry, or cold and humid environment?) We can however give as a typical European feed intake for dwarf SASSO hens on the ground close to 120g of feed at the peak of lay. The body weight gain, as well as the consumption time and the duration of the empty feeders will determine the peak of feed intake. Therefore, always remember to monitor the feeding behavior of the hens.
After the laying peak
A laying curve consists of 3 important phases: the start of lay, the laying peak and the laying persistency. As we can see, the hen has maintenance and production needs.
These nutritional needs are increasing during the laying phase (increased production needs as well as the growth requirements), are at their maximum during the laying peak (growth need still required) and are decreasing during the persistency phase (decreased production, therefore production needs and no more growth necessities).
Thus, it is quite intuitive that it is necessary to decrease the nutritional intake by ingestion (and/or formulation) once the laying peak is over. Maintaining the same feed intake between the peak of lay and culling will result in fattening of the hen and a significant change in egg weight and a decrease in shell quality. It is therefore essential to monitor body weight gain, laying progress and egg weight to justify the decrease in feed intake. As soon as the hen's body weight gain is higher than the standards, or the egg weight is also increasing, it is necessary to lower the intake by one gram.
Also, the protein and amino acid requirements will not be the same. It is therefore necessary, once the peak of laying is over, and once the desired egg size is reached, to change the feed formula to a slightly less proteinic feed, and reduced in methionine (egg size), and lysine (growth in particular). At this stage, it is also important to monitor the quality of the eggshell. Indeed, a deterioration will lead to a decrease of the daily calcium consumption. However, we know that this consumption must be higher than 4g/d to ensure a good shell quality. A supplementation in assimilable calcium could then be necessary at the end of the laying period.
We would like to specify that the formula can be adapted to the environment. Indeed, we cannot consider that the hens' intake in a European winter phase will be the same as in a European summer phase. The formula can then be reviewed to increase the density and thus reduce the consumption time during the coolest hours. You can therefore contact your technical sales representatives to identify the needs.
Feed management during the production period
Finally, we wanted to discuss the management of feed in the barn. Indeed, it is important to respect the needs of the animals for the meals.
We always advise to divide the ration in 2 times: a meal in the morning, when they wake up, and a meal at the end of the afternoon, before nightfall. The reason is very simple: this respects the natural behavior of the hen which, in its "wild" state, will consume 60% of its feed ration about 6 hours before nightfall, and 40% in the morning when it wakes up. In the same way, a ration at the end of the afternoon will allow the hen to have the necessary calcium resources for the formation of the shell during the ovoposition which starts at nightfall. A single ration in the morning will force the hen to draw on her own calcium reserves to find the necessary calcium.
Therefore, we recommend feeding in 2 rations. The first one should start 30min once the lights turn on. This allows the roosters to mate the hens the first half hour, as long as the hens are on the ground waiting for their meal (period of very high activity when the roosters wake up). The time of the first meal should not be too late, otherwise there will be eggs on the floor. The daily peak of lay of the hens is 12 hours after the building has been turned off. If the hens are still on the ground 12 hours after the building is shut down, they will lay eggs on the floor.
The goal is to get the hens to eat quickly, so they can go drink and then go lay in the nests.
Finally, at 3 pm, we can start to distribute the evening ration, just before the second period of high activity of the roosters (to stimulate them) which is around 5 pm. This will give them time to consume the feed before the night.
During a hot day, we recommend not feeding during the hottest periods of the day. In exceptional cases, we can modify the lighting program to feed earlier in the morning and later in the evening to ensure that the hens are not digesting during the hot period.
Key points to remember
As soon as the first eggs are laid, we must consider new needs in the feed formula: production needs. At this stage, we must accompany the hens in this increase in production, while controlling the growth and the fattening state. Similarly, after the peak of lay, the needs change: the growth needs become minimal, and the production needs are not as high. It is therefore necessary to adapt the feed intake to avoid fattening of the hens or unnecessary egg weight gain.
In this article we have also mentioned some tips for feeding during the production period.