Content available in: Español (Spanish)
When we talk about the rearing phase of broiler breeder pullets, we look for help in broiler chickens’ starter manuals. The environmental conditions are essential, but the feeding management will be better if we think they are broiler breeder pullets and not chickens.
For the pullets’ management in this phase, our objective is not to obtain an excess on early bodyweight with voracious animals and great ease to gain weight because of its improved feed conversion ratio. Even an excessive yield would transform into a greater breast development. Therefore, the objective is to have uniform pullets without exceeding the recommended bodyweights. This allows weekly feed increments that supply the nutritional needs in each stage of the rearing without causing excessive weight gains.
Once the pullets arrive at the farm, the unloading process must be done quickly to avoid that trucks stay outdoors because it will cause loss of temperature and stress in the pullets.
The temperature must guarantee that pullets can sustain their body temperature since, during the first 5 days old, they pass to be poikilotherms animals to homeotherms.
To get optimum temperatures, it is necessary to pre-heat the house between 21 to 48 hours before pullets arrive. However, it depends on the season of the year
A relative humidity ≤ of 30% reduces the thermal sensation, and then the pullets feel cold. Under these conditions, a good practice is to increase the house temperature between 0.5 to 1ºC. If there is a high relative humidity (≥50%), the temperature must be decreased amid 0.5 to 1ºC. The effective house temperature together with pullets behavior will help us adjust the ideal temperature.
The ventilation must be turned off before the pullets’ placement to avoid unnecessary heat loss. Sometimes, it is preferable to pre-heat the house without litter extended on the floor. Once the floor reaches 28 degrees Celsius, the litter can be extended most uniformly.
The pullets from grandparent flocks with less than 30 weeks of age have 1 or 2 fewer temperature degrees during the first 7 days of age than those from older flocks under the same environmental conditions. At placement, these small pullets can require temperatures of 1 or 2 more degrees celsius.
Cloacal temperature control
Controlling the pullets’ cloacal temperature, we can know if the arrival and placement temperature have been correct. During the first 24 hours, the temperature must be between 40.4 to 40.6 ºC (It is acceptable between 40-40.8 ºC). To obtain adequate temperatures, small allotments can be made during the first days of life (especially for pullets from younger hens), although the density should not exceed 30 birds / m2.
Considering that cloacal temperature increases physiologically 1 ºC from 4-day old with respect to the of the 3 first days, the temperature increases up to 41 or 42 ºC. But it does not mean that we are overheating.
If there is not available a cloacal thermometer, the temperature can feel placing the pullets’ legs in the hand or cheeks.
It is frequent that it is not ventilated during the first days of life or that it is done insufficiently to avoid heating losses. Insufficient air renewal causes an increase in CO2 levels, which is odorless and can come unnoticed. The CO2 levels are caused by the effect of respiration and the combustion of heating. When these levels are above 3,000 ppm, it interfers with the development of the cardiovascular system and causes irregular water and feed consumption which favors the uneven start of pullets.
Minimum ventilation avoids air flow at the animals’ height and, as its own name says, provide optimal air quality to avoid heat losses.
The air inlets have to be directed towards the roof; This will prevent drafts at the height of the pullets by putting the cold air from outside in contact with the warm air on the ridge.
The rearing house negative pressure determines the air intake speed, which will be necessary for the incoming air to reach the ridge; it will depend, on the width of the house.
It must be ventilated on a timed basis, 5-minute cycles with a fan operating time of 20%, so that during the time that the fans are not operating, the hot air accumulates in the ridge and mixes with the cold air that comes from outside.
The minimum renewal amount will depend on the farm’s air volume; Following this dynamic, we are renewing 1.5 times the entire volume of air in the house every hour. A very effective way to assess it is using CO2 probes, and, especially in the first days, it can help us adjust the minimum ventilation so that there is the least loss of heat.
Provide sufficient feed space in the receiving area by covering 50% of the surface with paper and combining with older trays for the first 7 to 10 days. It will be necessary to use 1 tray for every 50 pullets, and they must be located between the main lines of feeders and drinkers to facilitate access to feed. It is important not to place the trays directly under or near the heater, where excessive heat can drive the pullets away from the feed.
The feeders must never be left empty, and the feed must always be fresh. Spreading feed in small amounts several times during the day encourages consumption. After the first 2 or 3 days, the feed trays should be gradually moved closer to the feeder system and then removed gradually over a period of several days.
It is necessary to distribute about 25-30 g of starter feed per pullet with the texture of sieved crumb (diameter of 1.0-2.0 mm), optimize the pecking behavior on the first day, and ensure uniform consumption of everything. This reduces the bird’s selection and the losses due to wastage, although there are other forms such as flour and micro-granule of 2 mm in diameter.
Nutritional characteristics of the feed
The nutritional characteristics of the feed may vary according to the strains and genetic lines. In the formulation of these feeds, it is necessary to favor feed ingredients with high energy and protein value, and highly digestible with low values of anti-nutritional factors. Exogenous enzymes (Beta-glucanases, Xylanases, phytases, etc.) in the feed improve its digestibility until the secretion of endogenous enzymes begins.
Being the feed a moderate quantity, we can start with smaller amounts that will help us make the feed easily available for the pullets and increase the size of the starting stock until reaching the recommended density.
Although it talks about “ad libitum” feed during the first days, this “ad libitum” must be controlled and weighted day by day. If it is not controlled, the pullets will be overweighted from the first weeks. Also, the feed will be spilled over the litter, hence, it will be consumed when pullets start the restriction period. Table 2 gives an idea about how many grams per day per pullet are needed from one day old. To obtain a good uniformity, make sure that all pullets start to eat and drink during the first 24 hours after the placement. This could be checked by touching the crop at 8 and 24 hours to detect water and feed. At 8 hours, it must occur in 65% of pullets and at 24 hours in the 95%.
Currently, in the hatchery, the pullets are subject to beak treatment by infrared. It must be ensured that the area marked by the beak treatment does not come close to the nostrils: it should be limited to the outermost region of the beak. On certain occasions, especially in birds from young mothers, they may feel pain in the beak area, which inhibits or reduces the consumption of feed and water and causes uneven start of the pullets. To avoid uneven start of the pullets, they can be treated with acetylsalicylic acid in drinking water, which will act as an analgesic.
The most frequent drinker system is that of nipple drinkers (8-10 birds/nipple), but we also find the bell type (1 for every 80 birds). We must control the water temperature before receiving the pullets to avoid overheating the water due to the house’s high temperature. If it is not controlled, it will cause a reduced feed intake. The ideal drinking water temperature should be between 10 and 14 ºC. For this, during the first days, we must sanitize the waterline a couple of times a day. Birds should consume 1 ml/hour during their early 24 hours at a 30 ml/min flow rate.
High pressure does not correspond to increased water consumption. Any more than the pullet can hold in the beak will lead to more water spills leading to more footpad injuries and a higher ammonia load in the farm environment. Too low a pressure can reduce water intake by up to 20%.
Birds spend the same amount of time drinking water whether the volume is high or low. To determine the correct water pressure setting, it is good to examine litter conditions below the nipple line.
At the reception, the nipple should be slightly higher than eye level. As the flock grows, an imaginary 45 ° angle between the nipple and the pullets back will ensure the best water intake. Daily management of the height of the drinker line will help you to maintain optimal water intake.
The first 24 hours on the farm, we must supply 24 hours of light. During the next 6 days, we can progressively lower the number of hours of light until 12 hours at 7 days of age and 8 hours at 14, depending on the feeders’ amount of feed.
The light intensity must be greater than 20 lux in the house during the first 5 days of life. To avoid irregular feed consumption and uneven distribution of the pullets, the variation in light intensity should be less than 20% at different house points.
The pullets must be evenly distributed over the entire available surface. The formation of groups can indicate air currents, low temperatures, or variation in light intensity. Birds accumulated next to the walls can be a consequence of:
Copyright Grupo de Comunicação AgriNews SL. All rights reserved. Reproduction of the contents of this page in any format or communication, electronic or printed, without express authorization is prohibited. Request authorization.
See other magazines