Friday, June 25, 2010

Measuring Hatching Egg Shell Quality

Measuring Hatching Egg Shell Quality
Clearly hatchability is important to both small flock and commercial poultry breeder flock owners. Maintaining hatching egg shell quality is important because of its connection with hatchability. The major factors that influence egg shell quality are genetics, diet, climate, housing and age of the hens. While the average poultry operation has limited control over most of these factors, the crucial significance of hatchability makes it is important to recognize and control egg shell quality where possible.
Obviously, eggs with thin shells are more likely to break, producing 'leakers.' While leakers are not usually set in the incubator, thin shelled eggs crack easily in the hen house, during collection and transportation, resulting in poor hatches due to contamination. In addition to the increased likelihood of shell breakage, thin shelled eggs that do not suffer breakage allow for higher water vapor loss during the entire incubation process resulting in dehydration and higher embryonic mortality. Those chicks that do hatch from thin shelled eggs have decreased livability during the first few days of life and poor overall performance because they get off to a slow start.
Egg shell color has also been questioned in regards to its affects on hatchability. While the scientific literature contains conflicting data regarding the relationship between egg color and hatchability, poultry producers have long held the belief that in typical brown egg laying breeds, light colored eggs will not hatch as well as those that are darker in color. Indeed, it is interesting to note that in certain songbird species (flycatchers) experimental evidence suggests that healthier more wellfed females lay more intensely colored eggs (Moreno et al., 2006). Thus, there is some evidence to substantiate the assumption that darker eggs hatch better than lighter colored eggs. Eggshell color may also be associated with egg shell quality. Therefore, producers have been trained to eliminate light colored eggs from consideration as hatching eggs due to their poorer hatching expectations.
Measuring shell quality: Determining shell quality involves estimating shell thickness. Although there are many methods for estimating shell thickness, egg specific gravity is the easiest and most widely utilized. There are two methods to obtain egg specific gravity measurements: the Archimedes method and the salt solution method.
The Archimedes method involves weighing eggs individually and then weighing the egg in water. Then the formula [dry egg weight/ (dry egg weight-wet egg weight)] is used to obtain the specific gravity. However, because eggs must be individually weighed, this method is seldom used. The salt bath method utilizes tubs of water each of which contains a greater concentration of salt than the previous tub (typical concentrations are 1.070, 1.075, 1.080, 1.085 and 1.090). The specific gravity of the solution in which the egg floats, is the specific gravity of the egg. Eggs are placed initially in the tub with the lowest salt solution concentration. The specific gravity estimate is recorded for those eggs that float. Those eggs that do not float are removed and placed into the next higher solution and so forth until all the eggs float. This method is popular because it allows for rapid measurement of large numbers of eggs, with minimal affect on the eggs or their hatchability. The best time to measure specific gravity is in the hatchery after the eggs have had a chance a constant temperature and to reach the same temperature as the salt solutions.
Measuring shell color: The shells of broiler breeder eggs can vary from white to almost chocolate in color. The cause of this variation in egg color is not known, but eggshell color measurements have been made using techniques ranging from visual estimation to sophisticated electronic measurements. However, digital colorimeters are generally best because they tend to remove the subjectivity from these measurements.
Experimental Procedures
Egg Selection and Handling: A total of 1,944 eggs were collected from five different broiler breeder flocks that were between 33 and 45 weeks of age. Eggs were labeled so that each egg individually could be followed through the testing, incubation and hatching process. For this study, cracked eggs, toe checked eggs and any misshapen, too small or large eggs, or dirty eggs were eliminated. Only eggs that would be acceptable hatching eggs by the commercial integrator were used. Eggs were hatched at the commercial hatchery using industry standards and after hatch, a hatch residue breakout was performed to determine fertility and time of embryonic mortality.
Specific gravity: Salt solutions were maintained in the egg storage room at a local commercial hatchery and measured after they had time to adjust to the temperature of the room. The salt solutions were check regularly for accuracy with a hydrometer and concentrations ranged from a low of 1.065 to a high of 1.090 in increments of 0.005.
Shell color: Eggshell color was determined for each egg using a colorimeter that gave a numeric measurement of shell color. This procedure removed human error from shell color determinations. Pure white eggs would have returned a reading of 100, while darker eggs had lower numbers. The eggs that were measured had a color range from upper 60's (dark) to the lower 90's (light colored).
Experimental Results
Specific Gravity and Hatch: Hatchability results are shown in Figure 2. These results indicate that eggs with a specific gravity of 1.070 hatch as well as those with higher specific gravities and that hatch is not negatively affected until specific gravity is 1.065 or lower. These results are different than those published by McDaniel et al., 1981 and Bennett, 1992, who report that eggs with specific gravities less than 1.080 had poor hatch and increased embryo mortality. This difference in results may be the result of genetic progress made during the last 15 years, or in experimental methodology.
Shell Color and Hatch: Figure 1 shows the relationship of how shell color relates to hatchability. These results show that the hatch of extremely light colored eggs is lower than the darker eggs. Since shell pigments are applied to the shell just prior to the egg being layed light egg color may be a sign of prematurely layed eggs caused by some type of environmental stress.
Summary
1. A measurement of specific gravity can be effectively used to rapidly evaluate the shell quality in broiler breeders.
2. Eggs with specific gravity values higher than 1.070 will hatch well while those lower will result in poor hatches and indicate poor shell quality.
3. Lighter colored eggs (color scores above 87) hatched at a lower rate than did darker eggs. However, the light colored eggs would be considered those which are 'extremely light' and not just a lighter shade.
References
Bennett, C.D. 1992. The influence of shell thickness on hatchability in commercial broiler breeder flocks. Journal of Applied Poultry Research 1:61-65.
McDaniel, G.R., J. Brake and M.K. Eckman. 1981. Factors affecting broiler breeder performance. 5. The interrelationship of some reproductive traits. Poultry Science 60:1792-1797.
Moreno, J., E. Lobato, J. Morales, S. Merino, G. Tomas, J. Martinez-de la Puente, J. J. Sanz, R. Mateo and J. J. Soler. 2006. Experimental evidence that egg color indicates female condition at laying in a songbird. Behavioral Ecology 17:651-655.

Balancing the eggs

Balancing The Egg
The development of the embryo is determined by the temperature inside the shell, the embryo temperature. This temperature will dictate the development, but with that also the hatchability and the quality of the day-old chick.
It is often assumed that this temperature is fully dependent on the temperature of the air. Although air temperature has a large influence on it, it is not the only factor and in some situations not even the most important factor to consider.
We want to keep the embryo temperature at a level of 100.0 to 100.5°F. This temperature inside the egg is the result of a balance between the heat production of the embryo on one side and the heat loss of the egg towards it's environment on the other side.
One side of the balance: heat production
During development, the embryo produces metabolic heat. This heat production depends on the moment of incubation. At start of incubation, the heat production hardly exists. The first signs of heat production can be observed around day 4. From day 8-9 onwards the heat production becomes so high that the embryo temperature will rise if we don't react on it. At day 18, the heat production is at its highest level. Once the embryo's starts to pip, the heat production rises again, due to the increased activity.
Not every breed produces the same amount of heat at a given moment in incubation. Broilers produce more heat then layer type birds, high-yielding breeds produce more heat then classical breeds, male lines do normally produce more heat then female lines and within one line males produce more heat then females.
Although there are differences in breeds, the effect of a higher embryo temperature is not equal for all breeds and lines. For instance layer breeds produce less heat then broiler breeds and therefore the embryo temperature will increase less, but the effect of 1 degree increase in layer breeds is much more dramatic then for broiler breeds.
The other side: heat loss
To keep the embryo temperature at the desired level of 100.0-100.5°F, we have to remove enough heat from the shell to compensate for the heat production. There are in principal four factors that influence the heat loss.
• Air temperature
A difference in temperature between shell and air will force the heat to flow either towards the shell (when air is warmer then shell) or from the shell (when shell is warmer then air). The bigger the difference in temperature is, the more heat will be transferred.
• Humidity
Humidity influences heat loss in two different ways.
Dry air can contain very little heat in itself. It is actually the water molecules in the air that carry the heat. We call this heat capacity: when more water molecules are present in the air (high humidity), more energy is stored per unit of air. This means that at a given temperature difference, humid air will remove more heat from the egg. As we normally incubate in a narrow range of humidity, this is not a major factor of importance. However, if we incubate at high altitude (low pressure), there are less water molecules in the air, even at the same relative humidity as at low altitude, and the heat loss of eggs will be more difficult.
Eggs evaporate water at a constant rate, to a total of 12 to 14% of their initial weight. This evaporation of water costs energy, and moisture loss will therefore reduce egg temperature. When relative humidity is high, less water is evaporated and less heat will be lost.
These two mechanisms work in opposite directions: A high relative humidity will increase heat loss through increasing heat capacity but at the same time decrease heat loss through decreasing evaporation.
• Air velocity
A major factor in heat loss is air velocity. At the same temperature difference, objects will loose more heat if air velocity is high. We know that and use that very effectively in broilers, when we apply tunnel ventilation. It is also known in humans, where we call it the "wind chill factor". For eggs this is exactly the same. Eggs in incubators that experience a high air velocity will loose more heat and therefore be colder then eggs at low air velocity. The difference can be as high as 2-3°F in embryo temperature at the end of incubation. This implicates that if air velocity differs between different spots in machines, the embryo temperature will vary, no matter how uniform the air temperature is. As racks and trolleys of eggs are blocking air velocity in a machine and air takes the way of the least resistance, it is easy to imagine that huge air velocity differences can sometimes be observed in commercial machines.
• Water spray
When the air in the machine is too dry, the machine will add water to compensate. As water needs energy to evaporate, this will cool the eggs that are close to this water spray. Although water evaporation has a cooling effect by itself and sometimes can be used to cool eggs, spraying huge amounts of water will decrease uniformity in embryo temperature, as usually the water is sprayed locally, and at places where there is already a high air velocity.
Practical implications
In the last decade, there has been done a lot of research in this area. By now we know that embryo temperature in commercial setters and hatchers is often quite variable, mainly due to differences in air velocity. This raises two questions:
1. Is it of practical importance, in other words, does it affect the embryo or the chick.
2. If it is important, can we do anything about it.
To answer the first question, yes, it is a very relevant factor affecting both hatch and chick performance. Practical experience shows that controlling embryo temperatures between acceptable ranges can result in a better hatchability and above all a better chick quality. Especially the influence on yolk uptake and closure of the navels is high, resulting in differences in first week mortality due to navel/yolk sac infections and e-coli infections. Research has shown that differences in embryo temperature away from the optimum, result in a significant difference in hatchability, but also in growth and feed conversion of broilers at 6 weeks of age. Also the development of the total embryo as well as specific organs like the heart muscle are influenced, resulting in for instance a difference in ascites susceptibility.
The second question is more difficult to answer. With a single stage machine, we can at least adjust the machine temperature to match the heat production of the embryo. Although this gives a explicit and nowadays well recognised benefit over multi-stage machines and will result in a better chick quality, not all single stage machines are equal.
Because the major important factor for embryo temperature is air velocity and to a lesser extent the place and function of the humidifier, a substantial part of the problem is in the design of incubators and hatchers, which is challenging incubator manufacturers. Only by creating an equal air velocity over all egg and avoiding local evaporation of water, a uniform embryo temperature can be achieved. Without control on these points, the laws of physics simply don't allow a uniform embryo temperature and with it a uniform and optimal development of the embryos.
Although a lot can be done to improve the uniformity and control of embryo temperature in existing machines, the fundamental issue has to be solved in the designing stage of new machines. A simple check on the uniformity in embryo temperature of 18 day incubated eggs at different spots in the machine will show how well the design of a machine handles the factors that influence heat loss of the eggs.
Incubators that provide a uniform embryo temperature will allow us to create a more optimal environment for all the developing embryos, resulting in a better hatchability, a better chick quality and a better bird performance.
PUBLICATION DATE: 23/02/2009
RATING
COMPANY: HatchTech Incubation Technology
AUTHOR: Dr. Ron Meijerhof - HatchTech Incubation Technology (The Netherlands)

Monday, June 14, 2010

Hatching Egg Sanitation

Hatching Egg Sanitation
A common management tool in the handling of hatching eggs is treatment of the eggs with a fumigant or other type of disinfectant to reduce the number of microorganisms on the shell surface. In addition, sanitation of the hatchery building, hatchery equipment, egg transportation equipment, etc., is critical to good hatchability and high quality hatchlings.
Penetration of the hatching egg shell by microorganisms results in embryonic mortality, weak chicks, high chick mortality, and poor chick growth. The most effective sanitation system involves treating the eggs as soon as they are collected from the nest and before microorganisms penetrate the shell. Several recent research studies have examined the effectiveness, safety and ease of use of common disinfectants currently available for use in hatcheries and on eggs.
User- And Environmental- Friendliness
A Canadian study (1, References) examined 23 sanitizers/disinfectants for positive and negative characteristics in respect to their use in the hatchery. Each sanitizer was rated for user- and environmental-friendliness based on general characteristics, environmental impact and necessary safety precautions, health concerns, reactiveness, and potential fire hazard.
Ratings on environmental impact and safety were based on disposal methods, hazardous decomposition products, handling precautions, and ease of preparation for use. Ratings relative to health concerns were based on danger from direct contact (inhalation, eye, skin and ingestion), carcinogenicity, mutagenicity, and toxic effects on reproduction. Each product was also rated for reactivity (compatibility with other substances), stability over time, corrosiveness and fire hazard (flash point).
The types of products tested included ozone, quaternary ammonium, iodine complexes, phenols, halogens, aldehydes, salts, alcohols, acids, and various combinations. The following products 3 were tested: formaldehyde, Glutacide, Quat 800, Germex, Quam, Super Quam, Tryad, Egg Wash, Coverage 256, Basic G & H, Iocide-14, Iodophor, Lysovet, 1-Stroke, Tektrol, D.O.C., hypochlorite or bleach, Chlorwash, Bioguard, H Peroxide, Virkon, Sanimist, and ozone.
The products that were rated user- and environment-friendly were Bioguard, Germex, Iocide-14, Lysovet, Super Quam, Chlorwash, Quam, Quat 800, 1-Stroke, and Coverage 256. Compounds such as bleach, peroxide and ozone were considered to be marginal in their user- and environmental-friendliness.
Most of the compounds tested should be used with protective clothing, and precautions should be taken against inhalation and eye and skin contact. Products which were deemed to have potential as severe hazards to eyes, skin, and respiratory system were bleach, formaldehyde, ozone and Tektrol.
Effectiveness Against Microorganisms
The 23 products listed above were also tested for their effectiveness against a variety of microorganisms on the egg shell (2, References).
Results:
•All of the sanitizers (except Basic G & H, Sanimist, and ozone) showed a general ability to reduce microorganism on egg shells to a negligible number.
•The active ingredient in Sanimist, chlorine dioxide, reacts with the protein of the egg shell cuticle which neutralizes it before it can effectively attack the microorganism.
•Although a freshly mixed solution of Virkon was effective, storing for 7 days caused it to be ineffective.
•Phenol-based sanitizers such as Tektrol, D.O.C. and 1-Stroke, were less effective than Lysovet, another phenol compound which also contains EDTA (surfactant and wetting agent).
Hatcheries should monitor the effectiveness of sanitizers/disinfectants by the use of air, swab, fluff or other microbiological sampling techniques.
Effect on the Embryo
Some of the 23 products tested caused embryo mortality and loss of hatchability (3, References). Virkon, Coverage 256, and Egg Wash, all of which contain EDTA, caused reductions in hatchability of 11 to 26%. They also caused below normal moisture loss during incubation ranging from 16 to 19% less than the formaldehyde-treated standard. Peroxide caused an increased loss of moisture from the eggs during incubation but did not affect hatchability.
Use of Ultraviolet Light And Air Filtering
A recent study (4, References) examined the potential of ultraviolet (UV) light as a user-friendly, safe method of sanitizing hatching eggs and as a means to "scrub" circulating air in the incubator. Pre-incubation treatment of eggs with UV light (254 nm) for 1, 3, or 5 minutes was much less effective in the control of bacteria on the shell than dipping eggs in 1% formalin for 1, 5, or 10 minutes. UV light-treated eggs had slightly less moisture loss during incubation, but hatchability was not affected.
Eggs treated with formalin before setting and then incubated in UV light with an air filtering system had lower bacterial counts and higher hatchability than those without the light (77.4 vs 71.4%). Late embryonic mortality was reduced nearly 30%. Pre-incubation egg treatment with sanitizers having a residual effect would also be helpful in preventing recontamination during incubation.
Timing of Egg Disinfection
In the case of hatching egg contamination, a good defense is truly the best offense. That is, a good sanitation program which prevents egg contamination is far superior to disinfection after the eggs are contaminated. At its best, disinfection is only partially successful.
The type of organisms involved and the immediacy of treatment will likely have a significant influence on the success of the disinfection. This has been demonstrated in studies by Cox and Bailey (5, 6, References) in which the shells of hatching eggs were inoculated with a strain of salmonella. The eggs were then treated with one of several disinfectants at 1 minute, 5 minutes, 4 hours or 24 hours after inoculation. On the average, there was a 77% reduction of the incidence of contaminated eggs when treatment was within 1 minute, 64% reduction for treatment within 5 minutes, 45% reduction for treatment within 4 hours, and less than 10% reduction for treatment within 24 hours. Thus, the time lapsed from contamination to treatment with a disinfectant is crucial to the success of the disinfection.
Immersion of the egg in the disinfectant was more effective than a spray, which in turn was more effective than foam application. Glutaraldehyde, quaternary ammonium and a viricide were ineffective. Polyhexamethylenebiguanide hydrochloride (PHMB), hydrogen peroxide (1%), and phenol (.2%) were most effective resulting in 95, 94, and 80% reductions, respectively, in contaminated eggs with 1 minute post-inoculation treatment and 95, 44, and 69% reductions with the 5 minute treatment.
It is obvious that the results of disinfection are greatly influenced by the timing of treatment and the type of disinfectant. The type of organism involved also will likely have a major effect on the results. Furthermore, the beneficial effect of disinfection on hatchability may be disappointing. In a recent study with chicken eggs (7, References), the effects of disinfection of nest-clean or dirty eggs ranged from no effect on hatchability to an increase of 2 percentage points for sanitized dirty eggs.
Although egg disinfection is often helpful in reducing contamination on hatching eggs, it is not a panacea and every effort should be made to produce a clean egg which does not need to be disinfected.
References
1.Scott, T.A., and C. Swetnam, 1993. Screening sanitizing agents and methods of application for hatching eggs. I. Environmental and user friendliness. Journal of Applied Poultry Research 2:1-6.
2.Scott, T.A., and C. Swetnam, 1993. Screening sanitizing agents and methods of application for hatching eggs. II. Effectiveness against microorganisms on the egg shell. Journal of Applied Poultry Research 2:7-11.
3.Scott, T.A., C. Swetnam, and R. Kinsman, 1993. Screening sanitizing agents and methods of application for hatching eggs. III. Effect of concentration and exposure time on embryo viability. Journal of Applied Poultry Research 2:12-18.
4.Scott, T.A., 1993. The effect of UV-light and air filtering system on embryo viability and microorganism load on the egg shell. Journal of Applied Poultry Research 2:19-25.
5.Cox, N.A., and J.S. Bailey, 1991. Efficacy of various chemical treatments over time to eliminate Salmonella on hatching eggs. Poultry Science 70 (Supp. 1):31.
6.Cox, N.A., and J.S. Bailey, 1991. Effect of chemical treatments to eliminate Salmonella on hatching eggs. Poultry Science 70 (Supp. 1):154.
7.Buhr, R.J., J.M. Mauldin, J.S. Bailey, and N.A. Cox, 1993. Hatchability of sanitized nest clean and dirty broiler hatching eggs. Poultry Science 72 (Supp. 1):157.
PUBLICATION DATE: 15/07/2009
RATING
AUTHOR: Henry R. Wilson, professor, Dairy and Poultry Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida

Sunday, June 6, 2010

Strategi Mengantisipasi Heat Stress Pada Broiler

Strategi Mengantisipasi Heat Stress Pada Broiler
Heats stress diartikan sebagai respon fisiologis, biokimia dan tingkah laku terhadap faktor fisik, kimia dan biologis lingkungan. Ayam akan mengalami stress jika mengalami perubahan lingkungan yang ekstrim, seperti peningkatan temperatur lingkungan atau pada saat toleransi terhadap lingkungan menjadi rendah. Stress bisa menjadi status tetap atau merupakan tantangan proses adaptasi ternak. Stress merupakan ungkapan umum tentang penyesuaian fisiologis dan perilaku seperti perubahan denyut jantung, respirasi, temperatur dan tekanan darah yang terjadi jika ternak mengalami kondisi yang merupakan stressor baginya.
Stress yang terjadi pada unggas di daerah tropis salah satunya disebabkan oleh tingginya temperatur lingkungan dan berpengaruh negatif pada produksi unggas,. Kerugian yang cukup besar karena dapat menurunkan produktivitas akan tetapi menaikkan mortalitas. Kejadian Heat Stress pada broiler biasanya dimulai pada umur 3 minggu. Pada saat temperatur lingkungan tinggi broiler sangat sulit mengatur temperatur tubuhnya.
Mekanisme Faali Terhadap Heat Stress
Hormon tiroksin dari kelenjar thyroid merupakan hormone-hormon utama dalam metabolism dan mekanisme panas karena perannya dalam merangsang metabolisme tingkat sel di seluruh tubuh . Peningkatan konsentrasi hormon pertumbuhan(T3 dan T4) dalam darah akan meningkatkan pula metabolism didalam sel-sel tubuh dan merangsang penggunaan oksigen serta meningkatkan produksi panas. Hal ini disebabkan karena peningkatan penggunaan karbohidrat, peningkatan katabolisme protein yang ditandai dengan eksresi nitrogen dan peningkatan oksida ternak yang berlebih.
Apabila unggas berada pada lingkungan bersuhu tinggi, maka ternak akan mengalami heat stress karena mendapatkan panas dari luar dan tidak dapat meyalurkan panas tubuh yang berlebih karena lingkungan luar sangat panas. Heat Stress menyebabkan penghambatan keluarnya Tiroksin Releasing Hormone (TRH) dari hipotalamus, sehingga terhambat pula keluarnya Tiroksin Stimulating Hormon (TSH) dari anterior pituitary dan menyebabkan sekresi T3 dan T4, sehingga proses metabolism berjalan dengan taraf yang mencukupi.
Pada saat broiler mengalami stress panas dalam arti bahwa kehilangan panas diatas temperatur kritis tingkat pernafasan meningkat. Broiler yang kepanasan akan mengalami hyperthremia yang akan menyebabkan kasus panting (Terengah-engah). Intensitas respirasi akan meningkat hingga lebih dari 20 kali lipat. Hal ini akan mempengaruhi keseimbangan asam basa dalam darah. Alasannya sederhana, pada saat megap-megap, broiler akan banyak kehilangan CO2 dan derajat keasaman darah akan menjadi lebih basa. Kondisi ini akan menghambat proses penangkapan oksiden oleh sel darah merah ayam. Kedua, stress kepanasan akan mengganggu proses konversi vitamin D3 menjadi bentuk atktifnya. Padahal bentuk aktif dari vitamin D3 sangat diperlukan dalam proses regulasi kalsium. Ketiga, sintesa asam askorbat atau vitamin C yang ikut membantu dalam proses pembentukan tropocollagen, menurun.
Selama sengatan panas dan stress kepanasan, terjadi produksi radikal bebas yang berlebih. Radikal bebas ini akan merusak membran sel. Organ yang sangat penting dalam proses pembentukan daging, seperti hati ,akan mengalami gangguan dalam integritas membran selnya sehingga terjadi gangguan dalam pembentukan ATP dan metabolisme sel. Disfungsi hati akan menyebabkan pecahnya pembuluh darah pada hati (Perdarahan pada hati).
Stress karena suhu yang panas dapat menyebabkan kondisi imunosupresi. Hal ini akan meningkatkan sensitifitas ayam broiler terhadap infeksi kuman lapangan. Di lain pihak musim kemarau atau pancaroba memungkinkan peningkatan jumlah partikel debu di lapangan, padahal debu dapat digunakan sebagai media penyebaran kuman, misalnya E. coli. Setiap gram debu mengandung lebih dari 105 (pangkat lima) partikel E.coli. Sehingga peluang kasus penyakit infeksi pernafasan akan menjadi semakin tinggi. Kuman E.coli seringkali bertindak sebagai penyebab infeksi sekunder kasus pernafasan kompleks. E. coli bersama dengan debu dengan mudah masuk ke dalam tubuh melalui paruh ayam yang terbuka saat panting karena heat stress.
Strategi Manajemen Mengatasi Heat Stress
Strategi manajemen nutrisi untuk mengatasi stress panas termasuk mengatur hal-hal tersebut dibawah ini :
1.Air minum
2.Kandungaan energi dan protein dalam pakan.
3.Kandungan vitamin dalam pakan dan air.
4. Perubahan dalam praktek pemberian pakan.
5. Waktu pemberian pakan
6. Feed additive
Air Minum
Lebih dari 70 % produksi panas selama heat stress berlangsung dikeluarkan melalui panting, dengan demikian ketersediaan air yang dingin selama musim panas akan sangat membantu. Penurunan temperatur air dan penambahan garam mampu meningkatkan konsumsi air minum untuk proses pengeluaran panas tubuh.
Energi Pakan
Faktor pembatas yang sangat penting mempengaruhi performans broiler pada temperatur yang tinggi adalah konsumsi energi dalam pakan. Ketika temperatur lingkungan meningkat diatas 21ÂșC, kebutuhan energi untuk maintenance menurun 30 kcal/hari. Walaupun kebutuhan energi maintenance rendah pada temperatur tinggi, banyak energi yang terbuang untuk menghilangkan panas. Formula pakan dengan tingkat kepadatan nutrient (density) tinggi agar dapat memenuhi kebutuhan harian untuk pertumbuhan pada saat terjadi penurunan konsumsi pakan.
Protein dan Asam Amino
Kebutuhan protein dan asam amino tergantung temperatur lingkungan, sekalipun kebutuhan protein terpenuhi, heat stress akan mempengaruhi performans ayam. Konsumsi protein diatas kebutuhan atau program pemberian pakan dengan asam amino tidak seimbang meningkatkan katabolisme dan mengakibatkan produksi panas ditandai dengan meningkatnya heat stress pada ayam terus menerus pada temperatur lingkungan yang tinggi. Pengurangan protein pakan dengan suplementasi yang cocok dari asam amino sintetis juga merupakan salah satu jalan mengurangi produksi panas. Dengan demikian disarankan mengurangi kandungan protein kasar dari pakan dan melakukan suplemen dengan asam amino sintetik untuk memenuhi kebutuhan pertumbuhan. Suplementasi Metionin hydroxyl analog lebih baik daripada DL-Metionin, dan sangat menguntungkan pada ayam yang mengalami stress panas karena dapat diserap secara langsung melalui difusi pasif, yang mana tidak memerlukan energy.
Vitamin-Vitamin
Penambahan vitamin C, vitamin A, vitamin E dan D3 diperbolehkan untuk memperbaiki performans ayam pada temperatur tinggi. Temperatur tinggi juga mempengaruhi metabolisme secara keseluruhan dan kerusakan oksidatif membrane sel sehingga membutuhkan nutrisi seperti vitamin C(sebagai antioksidan), untuk memperbaiki kondisi tubuh.
Dosis vitamin C sebesar 200 ppm/kg pakan mampu menghasilkan performans ayam yang lebih baik selama heat stress. Biotin juga dapat ditambahkan untuk mengurangi gangguan metabolik seperti fatty liver dan kidney sindrom selama musim panas. Vitamin E dengan dosis 250 mg/kg pakan pada kondisi heat stress dapat juga memberi keuntungan dalam mengurangi kerusakan oksidatif.
Elektrolit dan Buffer
Panting mengakibatkan peningkatan kehilangan CO2 secara berlebih sehingga pernafasan menjadi alkalosis. Perubahan keseimbangan elektrolit dapat mengurangi laju pertumbuhan broiler. Untuk melindungi hal ini diperlukan pemberian larutan elektrolit (anion dan kation) dalam formula pakan. Suplementasi sodium bicarbonate (NaHCO3) 0.5 % atau 0.3% sampai 1.0 % ammonium chloride (NH4Cl) dapat mengurangi dampak negative alkalosis yang disebabkan oleh heat stress.
Perubahan dalam praktek pemberian pakan
Performans ayam menurun pada kondisi temperatur sangat panas , disebabkan oleh konsumsi pakan menurun. Agar supaya konsumsi pakan dapat meningkat dapat dilakukan hal-hal seperti : peningkatan frekwensi pemberian pakan, pemberian pakan dalam bentuk pellet, penambahan lemak atau molasses untuk meningkatkan palatabilitas.
Waktu Pemberian Pakan
Pembentukan panas pada metabolism pakan terjadi 4 – 6 jam setelah pemberian pakan. Kematian dapat ditekan dengan cara pemberian pakan pada malam hari dan pembatasan pakan kira-kira 4-6 jam sebelum terjadi heat stress.
Suplementasi Probiotik
Diketahui bahwa heat stress berpengaruh terhadap pencernaan dan absorbsi nutrisi. Suplementasi lactobacillus dan streptococcus memberikan keuntungan pada ayam pada saat kondisi heat stress.
Bahan – Bahan Chemotherapeutic
Sejumlah senyawa mampu membantu dalam mengurangi stress yang berhubungan dengan hypothermia. Aureomycin mampu mengurangi pertumbuhan yang menurun karena stress, resinpine diketahui sebagai suatu alkaloid yang mampu melindungi ayam dari kehilangan CO2 akibat heat stress demikian pula thereby mampu mempertahankan keseimbangan asam-basa dalam darah selama heat stress terjadi.
Kesimpulan
Temperatur tinggi sebagai stressor pada broiler mampu menyebabkan gangguan produksi sehingga terjadi penurunan performans. Meminimalisasi pengaruh negatif dari panas melalui modifikasi pakan adalah hal yang ideal dan biaya yang lebih murah. Penggunaan vitamin-vitamin tertentu yang dapat menekan kematian ayam pada saat terjadi heat stress sangat dianjurkan.

About Lux and Light

About Lux and Light
By Ron Meijerhof, Senior Technical Specialist, Hybro B.V. - Light is extremely important for chickens. Not only do they need light to see and find food, water, nests etc, but also their reproductive system is triggered by light. To understand how it works, we have to look at both light and birds.
What is light?
Light is a form of electromagnetic radiation, like radiowaves, rontgen waves etc. Radiation with wave lengths between approximately 300 and 800 nm (1 nm is a millionth part of a millimeter) can be seen by the human eye as light. The wave length determines the colour of light. 300 nm is violet, then comes blue, green, yellow, orange and the longest wave length of 800 nm is red light. If the wavelength is just below 300 nm, we talk about ultra-violet, where a wavelength just above 800 is called infra-red. Although we can’t see ultra-violet and infrared, we know they exist. Ultra-violet light colours our skin and infra-red can be felt as heat and can be made visible with an infra-red camera.
We see coloured objects because they reflect a certain wave length. A red object absorbs all wavelengths except red. It reflects the red colour which is seen by the eye, and that is why we see the object as red. White light is a mixture of all colours, which means that a white surface reflects all colours. Black objects reflect no colour. That is why black objects get warm more easily, as they absorb all incoming light.
The temperature of light
We normally consider light with a lot or red/orange colour in it as warm (candle light), while bright white light with a lot of blue/green colour seems cold and hard.
The colour of lamps is often given as a temperature in degrees Kelvin (oK). Kelvin has the same range and magnitude as Celsius, but doesn’t start with 0 at the temperature of melting ice, but at the absolute zero, which is -273oC. A high colour temperature stands for very short wave lengths (blue/green) and low temperatures represent long wave lengths (red/orange). This is a bit confusing, as a high colour temperature (blue/green) for us feels as a cold colour, where a warm colour as orange or red is measured as a low temperature.
This has to do with the way these temperatures are determined. A plate of steel is warmed up until it starts giving off light. At approximately 2000-3000 oK the steel is red hot, and gives off red light. When we warm it further, it passes through all the colours until it becomes white at about 6000oK. When we heat it up further, the steel even becomes green and eventually blue/violet. Normal daylight has a temperature of about 6500oK.
The intensity of light
The intensity of light is measured in lux, which is the amount of electromagnetic radiation (lumen) received per surface area. For a normal lux meter it doesn’t matter if the electromagnetic radiation is in the wavelength of blue colour or red colour, it just measures the radiation.
Birds and humans
Birds and humans do make a difference between wavelengths. They can see especially well in bright, white light, which contains a lot of blue and green, so short wave lengths. Also humans experience bright white light as very intense. However, the reproductive system of chickens is not so much influenced by the light that they see, but by the light received in the brain. The brain of a chicken contains light-sensitive cells, and they are stimulated by the light that goes through the skull.
But not all light goes through the skull evenly. Especially long wavelengths can penetrate into the brain. Compare it with music, where the bass (long wave lengths) can be heard easily outside a house or car. We can also see it if we have a torch shining on our hand, where the red waves will go through the skin and can be seen on the other side, colouring it red. This means that chickens use bright light (short wave length, high amount of blue/green wave length) to see, but they need red light (long wave length) for stimulation of the reproductive system.
So if we want to stimulate eating behaviour (broilers) but also activity of breeders to find the nest and avoid floor eggs, we have to give them bright cold white light, with a high amount of blue/green. If we want to stimulate the reproductive system, we have to give them warm light, with a high amount of red/orange. If we use light in chicken houses, we must be aware of this.
•If we simply measure the amount of lux, we might find that the house is light enough. But if that light is very bright and there is only a small amount of red colour in it, changes are that the birds don’t get stimulated enough.
•Lamps with a lot of red wavelength in it do not seem very bright for us, where the actual lux reading can be surprisingly high. White bright light will seem more intense, where the actual amount of lux can be low.
•As birds respond to the red wavelengths, white bright light will not be very effective for production. If we need to give enough red light with this light source, the total light intensity has to go up very high. This bears the risk that the birds are stimulated in their behaviour, resulting in nervousness, stress and pecking. Giving only red light will not work so well, as it will for instance increase the risk on floor eggs.
•In rearing, often light bulbs (warm, yellow/orange light) are used because the can be dimmed very well. When these birds are transferred to a black-out production house with high frequent bright white TL light, the total light can go up, but the amount of red light might not increase that much or even decrease. And as birds get stimulated by an increase in red light, their production might be delayed.
•Broilers need to be stimulated to find food and water and move around, so they can benefit from a high amount of green/blue colour in the lamps. Breeders in reproduction will be stimulated by a high amount of red/orange colour in the lamps, but they need enough white light to avoid floor eggs.
To avoid problems, we must:
•Not only look at lux, but also at the colour of the light
•Ensure that broiler breeders step up especially in the red light fraction coming into production.
•Make sure birds get enough white light to stimulate their behaviour.
•Make sure broiler breeders in production get enough warm, red/orange light to stimulate their reproduction.
Source :http://www.thepoultrysite.com/articles/715/about-lux-and-light