Thin shelled eggs can be caused by a number of reasons; Age of flock, incorrect Ca:P, low levels of calcium, P or Vitamin D in the ration. overcrowding of birds and incorrect amount of feed being fed so birds not consuming enough. Not feeding enough times during the day. Feeding to late at the last feeding so birds are not getting enough feed intake before lights out, infectious bronchitis (clinical or subclinical), poor absorption of nutrients, incorrect size of calcium so not enough retention time in the gizzard. A high egg production and using powdered calcium instead of calcium particles, heavy metals in the calcium or P matrix eg vanadium. Poor source of calcium.
The age of flock is very important to know because if this case in the beginning of laying cycle this means that poor prelayer ration -in this case- it is defecult to resolve this thin egg.
If the case in older flock ( more than 45 weeks of age) may be there was an increased size of egg or incorrect particle size of calcium carbonate ( it should be about 50% between 2-4 mm)
The amount of feed intake is very important to calculate the amount of calcium intake daily.
Some of diseases may be cause thin eggs ( mycotoxins as example).
We can be more affective if we know the feed analysis and feed intake and the age of flock.
Thank s both of you - Robert & Mossad Hashim for pointing out the valuable factors of causing thin shell egg,Age of the hy-line flock was 44 wks few months internal the condition became repeated , this is the third time of repeatation.. there was one thing in vaccination history IB live vaccine only used during the rearing period, but he did not use IB killed vaccine still now, regarding this issue can I suggest IB killed ,In Bangladesh now the climate is too hot , I am agree with both of you the particle size of lime stone or oyesther shell, I will suggest him accordingly,except this all possible nutritional imbalance was corrected ,Mr mosad ,you mentioned one very important thing that how much feed consumed daily ,depending on this - calorie : protein ratio & calcium:phosphorus ratio also adjusted,In the mean time the thin shell somewhat developed, Now I am confusing about whether I suggest IB killed vaccine or not.
Nutritional deficiencies cause thin egg shells. Try using digestive enzymes to improve digestion and absorption of feeds. This is one recommendation we give to layer farms here in the Philippines.
Shell Quality and Nutrition
Poor calcium nutrition is responsible of a decrease of the number of saleable eggs and of the egg colour. A large part of the mortality after 50 weeks could be related to demineralization of birds and broken bones. The layer feed, with a part of the limestone in particles, with a correct calcium level has the capacity to express the genetic potential in term of shell quality but…time of feed distribution is the key factor to obtain and to maintain a shell quality until end of lay. Maximum of feed has to be distributed at 1 to 2 pm.
A midnight lighting programme improves also the shell quality.
3 to 4 g of large particles of limestone distributed every day at 3 pm is a good technique to improve the shell quality after 50 weeks
1. Calcium nutrition and productivity
The main effects of poor calcium nutrition on productivity can be summarized like this:
Percentage of lay: The productivity is generally not affected by poor calcium nutrition. Birds maintain there productivity for a long period by reducing the shell weight and using calcium from their bone.
Egg Weight: not affected with a poor calcium nutrition
Shell Quality:
- at beginning of the laying period at around 30-35 weeks, generally we observe a less uniform shell colour, a thinner shell and a percentage of broken eggs slightly higher. Some pimple eggs appear with a slight roughness on the small end of the egg. In practice, a lower shell colour and appearance of roughness are the first signs.
- in the middle of lay the percentages of pimple eggs and the percentage of broken eggs increase. More shell eggs are found in the manure.
- end of lay: only 2 solutions, depletion or sell eggs at the egg processing plant.
Mortalities: In case of poor calcium nutrition, birds give the priority to shell quality (reproduction is the priority for all species) and consequently, week after week, birds are more and more demineralised. Osteoporosis appears responsible for more bone fractures. 50% of the mortalities observed after 50 weeks could be related to poor calcium nutrition.
In conclusion, saleable eggs per hen housed, liveability, age at depletion and egg price are directly influenced by the calcium nutrition.
2. Layer Feed
In a good layer feed, a part of calcium has to be providing in large particles to allow storage in the digestive tract for the shell formation. Large particles of limestone are retained and allow satisfying the requirement in Calcium at the end of the night. Low level of calcium in the gizzard at the end of the night is responsible for a lower shell quality and osteoporosis at end of lay (see Table 1).
Table 1: Influence of a large limestone size on shell thickness
Calcium
Sources Calcium Particle sizes (%) Shell
Thickness
mm
> 4
mm 2-4
mm 0.8-2
mm < 0.8
mm
Large LM + fine LM 13 41 6 50 0.353
Fine LM - - - 100 0.312
LM = limestone Scheideler (1998)
Wonokoyo Feeds has been designed to express the genetic potential in term of shell quality, with an adapted Calcium level and a part of limestone in Large Particles.
3. Techniques to be used in the farm
Feed to use
- Distribute a Prelay Feed at the right moment: Around 12 days before the production of his first egg, a bird store a small quantity of Calcium in their medullary bones. For this reason, we need to use the Prelay feed when first eggs are obtained or around 2 weeks before 2% lay.
- Use the Layer Feed at 2% lay: The main reason of a poor shell quality seen very early in lay (30-35 weeks) is due to the use of the layer feed later than 2% lay. Birds in lay eating a Prelay feed need enough Calcium to avoid a deficiency. Their medullary bone reserves disappear in few days and birds will produce poor quality eggs during all their life and will suffer of osteoporosis very early. Table 2 shows the effect of a Calcium deficiency immediately after a decrease of the Calcium level.
Table 2: Shell weight evolution on the following days after a decrease of the calcium level
Calcium level 1,75% 1 %
Day 1 - 7 % - 12 %
Day 2 - 9 % - 16 %
Day 3 - 11% - 23 %
Day 4 - 10 % - 20 %
Day 5 - 16 % - 25 %
Roland ( 1978 )
- Use a Layer Feed with a higher Calcium content at 50- 55 weeks: There are 2 reasons for that. The absorption of Calcium is a little less efficient on old birds and the shell weight is slightly heavier.
Absorption of Calcium
A small quantity of Calcium is stored in the medullary bones. The quantity available is very low and used mainly at the end of Calcification period. The Calcium is not absorbed when birds are not in calcification, a small quantity only to replenish the medullary bone.
Birds need Calcium when they are making their shell. During all the calcification period, a layer secretes a high quantity of Chlorhydric Acid to solubilise the calcium. Around every minute, by gizzard contractions, the calcium is expelled in the intestine for absorption. Some experiments have demonstrated that it takes no than 30 minutes between the moment that birds ingest some limestone and the moment that Calcium is incorporated into the shell.
Consequences are the following: Limestone in large particles is a way to increase the quantity of Calcium at the end of the Calcification (end of night). Birds need to ingest their calcium mainly afternoon which is the beginning of the shell formation.
Management in the Farm
- Adapted feed distribution time. Birds begin their calcification afternoon and already finished for around 40% of birds at light on. Birds have a specific appetite for calcium at beginning of the shell formation. It is why feed distribution has to be done afternoon. We advice to distribute:
¤ all the feed (100%) afternoon at around 1-2 pm and to be sure that there is enough feed remaining in the feeders at light on
¤ 85g of feed afternoon at 1-2 pm and 30 to 35 g at 7 am
We consider that only one feed distribution is the best techniques in adapting the quantity according to obtain empty feeders at around 9-10 am.
- Adapted Lighting programme. By using Midnight lighting (1h30) birds can ingest Calcium during their calcification; it is why the shell quality is always improved with the midnight Lighting.
- Limestone distribution. A distribution every day at 3 pm of 3-4 g of limestone (2 to 4 mm) improves the shell quality mainly after 50 weeks.
Table 3: Effect a distribution of 1, 2 or 3 g of extra limestone with a size of 3 to 4 mm
on eggshell weight (ESW), eggshell thickness (EST), cracked eggs and broken (CE)
Table 3: Effect a distribution of 1, 2 or 3 g of extra limestone with a size of 3 to 4 mm
on eggshell weight (ESW), eggshell thickness (EST), cracked eggs and broken (CE)
i think liquid calcium supplementation through water (preferably through water channel not by nipple drinkers) could be tried for 3-5 days for its effect which could gives idea about the amount, type and availability of calcium to the birds. The picture shows only damaged egg shells only but incase of IB one can also expect misshapen, wrinkled and even small sized eggs also. Being summer we can also go for electrolytes like sodium bicarbonate, potassium chloride, betaine etc. to alleviate the heat stress in birds.
A very important nutrtional factor for layer is manganese. Results of my researches indicated that supplementing 80-120ppm MnSO4 in diet increased egg shell thickness and decreased cracking rate about 10-12%. Please try.
Hi Guys,
in the tropics, especially in areas around Ghana, Cote D'Ivoire, cameroun and Nigeria, this economic problem is normally associated with new castle disease and or to immunosuppression associated with subclinical mycotoxicosis. So a way out is to apply your NCDV or go for a more potent anti-toxin additive or reduce the level of byproduct feedstuffs in your formula. It also helps to ensure your birds are getting good supply of Vit D, E, as well as Ca and P. It might also mean that your flock is getting old and ready to be culled off.
Over here, we tend to see more eggshell quality problems during the hot season when feed intake suddenly drops and the hens start panting excessively to dissipate their body heat. Hens kept in traditional open house system will be the worst affected.
If possible, we try our best to minimise any sudden drop in feed intake, and if this cannot be entirely avoided (as is the case), then we formulate a higher nutrient density diet for the hens. It is quite normal for us to increase the levels of essential amino acids, calcium, available phosphorus, vitamins and trace minerals by between 5% to 10% over normal levels during periods of hot weather. To stimulate the hen's appetite, I see good results using Full Fat Soybean Meal while restricting the dietary crude fibre level. Other than this, sodium bicarbonate should be used to partially replace a part of the Salt. A very effective way to strengthen eggshells is to supplement the feed with chelated zinc and manganese. Zinc is especially critical as it is required to activate the enzyme responsible for eggshell formation.
Infectious diseases can also cause eggshell problems especially when the immunity of the hens are depressed by the hot, humid weather or even by mycotoxins in the feed. Here, Newcastle and Infectious Bronchitis are the main culprits. Farmers here will vaccinate ND+IB+EDS killed vaccine between 14-15 weeks old to protect the hens throughout the egg production period.