Environmental heat stress is one of the most challenging conditions in the world which have adverse impact on the industry of poultry. Broiler chicken strains are delicate to heat stress primarily due to not having sweat glands. The current study was aimed to investigate the effects of heat stress exposed on growth performance and Bio-physiological characteristics for (Cobb, Hubbard and Arbor Acres broiler hybrids) under the summer season when environmental conditions of Egypt were revealed. A total of three hundred one day old (one hundred birds from each hybrid) at one day of age were brooding under the same conditions of water, diet consumed, breeding system, vaccines and medications used during the period birds life even slaughtering age. The three strains were randomly divided into twelve groups (three strains "Cobb, Hubbard and Arbor Acres" X two treatments "control group and heat exposed group" X two replicates X twenty five chicks).The degrees of environmental temperature and relative humidity during housing are (Environmental temperature = 32°±2 Celsius degree, Relative humidity =50±5 percentage) for control group and (Environmental temperature =40°±2 Celsius degree, Relative humidity= 20±5 percentage) for the heat stressed group. The body weight, body weight gain, edible parts of carcass (carcass, thigh, drum, breast muscles and giblets weight) and inedible parts of carcass (blood, feathers, head and legs weight) were recorded to heat stressed group and control group. Lymphatic organs such as spleen, thymus and bursa weight were measured also. The last results concluded that the Cobb strain showed the best growth performance and carcass characteristics under heat stress condition, while the Arbor Acres strain considered the best strain which didn't effected a lot in their rectal temperature such another strains with heat exposure. The Arbor Acres strain for each group (control and treated) have the highest viability. The control group and Hubbard strain showed an increase in bursa weight compared to heat exposed group and another strains. It was concluded that the Cobb strain has the best performance under heat stress comparing to the other strains broiler chicken.

The poultry industry in Egypt is one of the most important industries that contribute in providing the source of animal protein, which is characterized by high nutritional value, cheap price and high conversion coefficient of food compared to red meat. This industry is characterized by several characteristics, the most important speed of turnover of capital as well as not need a large agricultural patch, In addition to the relative increase in food conversion efficiency compared to other types of animals. The industry is also characterized by high return and low capital required to invest in this field compared to other productive projects. The problem of research is the high price of the prices of the inputs of the production of poultry and the low quality of the market, and fluctuation of market prices of the final output, which affects the revenue and thus affect the size of the economic project. Therefore, the study aimed at estimating the economic yield of the poultry farms in the fattening nurseries in Qalyubia governorate. These farms are characterized by a short cycle of the capital cycle in order to contribute to raising the level of individual income in the rural sector. It also provides job opportunities for young people. Of the animal protein, and based on published data and the use of field study for a sample of the municipality of Qalyubia, the research reached some results, including:  1- The average number of farms of broiler fattening was about 1.6 thousand farms by 6.67% of the total number of farms at the level of the province of Qalyubia. 2- The study of the most important problems and obstacles facing the poultry growers found that the problems of production and marketing were the high prices of chicks used in fattening, lack of quality chick, high feed prices, the lack of trained labor, the problem of control of traders and brokers in price, and the problem of irregular market price . 3- By dividing the sample of the study into three production capacities, it was found that the net yield of the first capacity (12.9-6 thousand birds) amounted to 308.9 thousand pounds / cycle, and net return of the second capacity (less than 6 thousand - more than 3.6 thousand birds) LE 323.2 thousand / cycle, while it amounted to about 274.1 thousand pounds / cycle for the third capacity (3.6 - 0.8 thousand birds). 4- The estimated profitability of the pound for the investor for the three capacities (first, second and third) was respectively 1.05, 1.12, 1.31 thousand pounds.

The aim of this study was to use spreadsheet software (Excel) to solve linear programming models in formulating least cost rations of egg layers. The ingredients used are corn, wheat, soybean meal, barley, wheat bran, protein concentrate, limestone, salt, dicalcuim phosphate, vitamin and mineral premix, vegetable oil. Results showed that the starter optimum ration for layers from (0 – 6) weeks, consist of these ingredients (9.40, 26.91, 16.38, 38.71, 4.51, 0.95, 1.09, 0.25, 1.18, 0.25, 0.33)% respectively and from (6-12) week of (0, 73.43, 8.72, 0, 14.37, 0, 0.99, 0.25, 1.39, 0.25, 0.57) % respectively, from (12-18) week (0, 78.36, 6.17, 0, 12.02, 0, 1.44, 0.25, 0.87, 0.25, 0.61)% respectively, from (18 week - start of production) (0, 75.55, 13.85, 0, 3.81, 0, 4.25, 0.25, 1.16, 0.25, 0.86 )% respectively , and during productive period  from (0, 66.93, 10.62, 0,0, 9.09,9.01, 0.25, 3.82)% respectively, and the cost of these ration was 160.6, 130.70, 123.60, 145.22, 195.95) Iraqi Dinar/kg respectively. Results also show sensitivity report of allowable increase and decrease in ingredient cost and in constraint values and the shadow price.