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There are two main factors that stimulate the onset of laying in the flock:
\nSome useful recommendations:<\/p>\n
- \n
- Body weight<\/li>\n
- Photoperiod<\/li>\n<\/ul>\n
In the absence of other stimuli, hens will begin to lay when they reach an Based on the target of egg production and egg size each type of layer hen has a target light program and body weigth to start the light stimulation<\/div>\" class=\"glossaryLink\"> appropiate body weight <\/span>. However, the duration of the photoperiod can stimulate or delay the onset of lay as follow:<\/p>\n
- \n
- Stable or increasing photoperiods with a duration exceeding 14 hours will early stimulate the onset of lay.<\/li>\n
- Stable photoperiods with a duration of less than 14 hours will delay the onset of lay.<\/li>\n<\/ul>\n
Decreasing photoperiods should never be used in production period. <\/strong><\/p><\/blockquote>\n
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<\/a>\r\n\r\n\t\t\t<\/div>\r\n\r\n<\/div>\n<\/div>\n<\/div>\nHow to choose the right stimulation age<\/h3>\n
Normally a \ufb02ock should be kept with a stable photoperiod until light stimulation starts. If hens are in the weight range<\/a>, a standard recommendation for standard production is 119 days of life. However, this may vary according to two factors:<\/p>\n
- \n
- Flock body weight status:<\/strong> If the birds\u2019 body weight is far below the standard it is preferable to delay light stimulation for at least one week. Equally, if the <strong>Coefficient of variation (CV)<\/strong>: is a standardized measure of dispersion of a probability distribution or frequency distribution. It is often expressed as a percentage, and is defined as the ratio of the standard deviation to the mean <\/div>\" class=\"glossaryLink\"> CV <\/span> is very high and the weight of part of the \ufb02ock is far behind the standard, later light stimulation is preferable.<\/li>\n
- Accumulated egg weight objective:<\/strong> egg size strongly correlates with the size of the bird. A simple way to get heavier birds in the production on- set is to delay light stimulation. Age at 50 % lay and body weight at 50 % lay are two values<\/a> that can greatly help to forecast the egg weight.<\/li>\n<\/ul>\n
How to deal with natural day length<\/h3>\n
The light program in open houses should take the natural day length at the stimulation age into account. Determine the light program during rearing as explained in chapter growing.<\/a> Stimulation should di\ufb00er depending on the day length.<\/p>\n
- \n
- Increasing day length period:<\/strong> \ufb02ocks risk being stimulated by natural light before they reach the correct body weight. To avoid this, the arti\ufb01cial day length should always be longer than the natural day length until the \ufb02ock is ready to be stimulated. This should be considered in the rearing light program.<\/li>\n
- Decreasing day length period: <\/strong>\ufb02ocks exposed to decreasing day length can show delayed onset of lay. To avoid this, create an arti\ufb01cial day length longer than the natural day length from week 10.<\/li>\n<\/ul>\n
To achieve this goal, use the app: H&N lighting program.<\/strong><\/p>\n
How to apply light stimulation in a \ufb02ock<\/h3>\n
Once the light stimulation age is de\ufb01ned, light stimulation starts with an initial photoperiod increase. Take the following into account:<\/p>\n
- \n
- Increase the day length at least one hour after sunset, or after switching o\ufb00 the lights.<\/li>\n
- Light intensity control in the laying house should be slightly higher than in the rearing house.<\/li>\n
- Light distribution should avoid dark area and shady areas<\/li>\n
- Keep light sources clear.<\/li>\n<\/ul>\n
Subsequently, the photoperiod must be increased weekly. Light increases should be at least half an hour, although a higher increase is possible if the laying percentage increases rapidly. The more light hours the hens have, the more time they will use to consume feed. It is therefore important to achieve at least 14 hours of light to allow the \ufb02ock to reach a proper feed intake.<\/p>\n
Sexual maturation and onset of lay<\/h2>\n
At the start of their productive life, hens develop their secondary sexual characteristics. This is a good indication that the bird\u2019s hormone development is correct. In addition to the start of the reproductive capacity (and therefore production of eggs) other changes occur in the bird\u2019s metabolism.<\/p>\n
One of the most important is the ability to capture calcium to create intramedullary bone<\/a>. It is very important that the birds develop this type of bone to ensure good quality eggshells during the late lay period. Good practice is to use a pre-lay feed as explained in chapter nutrition.<\/p>\n
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Feed<\/h3>\n
The birds need a good quality feed, with the structure and nutrient<\/a> density necessary to suit their feed intake as well as provide their egg production, growing and maintenance requirements. Nutrient requirements in this phase increase rapidly so the feed intake of the birds should increase simultaneously. If not then the birds\u2019 nutrient requirement will not be met and they will be forced to mobilize their reserves. This may lead to soft bones and potentially harm the bird for the rest of the laying cycle. Switching to a layer diet with more than 2.5 % calcium stimulates the birds to lay eggs. This feed phase I aims to cover the requirements to obtain the maximum egg mass. See nutrition chapter for further details of feed recommendations.<\/p>\n
Ventilation & temperature<\/h3>\n
Proper ventilation<\/a> should be used to guarantee good air quality in the house, and ensure a low concentration of gases and dust. At the same time the temperature in the house should be optimally maintained between 18\u201324 \u00b0C with a relative humidity of 50\u201360 %. Birds do not tolerate temperatures above 30 \u00b0C well, especially if high temperatures are combined with high humidity. During heat stress, ensure that su\ufb03cient air circu- lates around the birds. The use of additional fans as well as evaporative coolers should be considered to reduce the house temperature.<\/p>\n
Water<\/h3>\n
Cool water<\/a> of good quality should always be available with the required water \ufb02ow. Continuously monitor the water quality. Water consumption is normally 1.5\u20132 times higher than feed consumption. It is highly recommended to monitor the water consumption for early detection of possible problems. Regular cleaning and \ufb02ushing of the water lines as well as the supply water tank is essential. Water consumption will clearly increase at 10\u201314 days prior to the onset of lay. During this period, the ovary and reproductive organs and medullary bone will develop, and water will be stored in the follicles of the ovary.<\/p>\n
Space<\/h3>\n
The birds should have enough space<\/a>, especially in hot climates. Important aspects are not only cm\u00b2 of cage \ufb02oor\/bird, but also the height of the cage and how many cm of feeder, and how many drinkers are available per bird. The temperature should be between 18\u201324 \u00b0C.<\/p>\n
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<\/p>\n<\/p>\n
Onset of lay<\/h2>\n
% LAY<\/strong><\/h4>\n
- Decreasing day length period: <\/strong>\ufb02ocks exposed to decreasing day length can show delayed onset of lay. To avoid this, create an arti\ufb01cial day length longer than the natural day length from week 10.<\/li>\n<\/ul>\n
- Accumulated egg weight objective:<\/strong> egg size strongly correlates with the size of the bird. A simple way to get heavier birds in the production on- set is to delay light stimulation. Age at 50 % lay and body weight at 50 % lay are two values<\/a> that can greatly help to forecast the egg weight.<\/li>\n<\/ul>\n
- Flock body weight status:<\/strong> If the birds\u2019 body weight is far below the standard it is preferable to delay light stimulation for at least one week. Equally, if the <strong>Coefficient of variation (CV)<\/strong>: is a standardized measure of dispersion of a probability distribution or frequency distribution. It is often expressed as a percentage, and is defined as the ratio of the standard deviation to the mean <\/div>\" class=\"glossaryLink\"> CV <\/span> is very high and the weight of part of the \ufb02ock is far behind the standard, later light stimulation is preferable.<\/li>\n
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