Thesis (M.S.)--University of Wisconsin--Madison, 1984. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies.

Introduction : World poultry meat consumption consists of three major segments: broilers, turkeys, and other poultry which includes spent egg layers, spent breeder hens/males, ducks, geese, guinea-fowl, pheasants, quail, ratites, ostriches and emus. Broilers clearly dominate the world poultry consumption contributing about 70 percent to the world poultry market. Turkeys account for about eight percent while other poultry provides the balance of 22 percent (Roenick, 1998). The world broiler industry has been, and continues to be a very dynamic industry. It has been typified with unprecedented growth in terms of production. In 1961, the world produced 6.5 billion broilers. By 1990, the total annual production was a little over 27 billion broilers and by 1996, total world production had grown to 35.3 billion (Van der Sluis., 1999). This represents a fivefold increase in 35 years, and it has not stopped growing since, with world production surpassed 38 billion in 1998 (Van der Sluis., 1999). In Africa the human population was estimated to be 819.9 million, while the total poultry population of the continent was estimated as 1.133 million chickens, 15 million ducks and seven million turkeys in 1998. Production scale being 1.781701 metric tones (MT) of hen eggs, 2.269000 MT of chickens’ meat, 32.824MT of turkey meat and 52.989MT of duck meat (Gueye, 2000). Commercial poultry products are also imported and exported. For example, 12.000 metric tons of poultry meat was estimated to have been exported from South Africa in 1999, whereas 87.000 and 10.000 metric tons of poultry meat was imported into South Africa and Egypt, respectively (Gueye, 2000). In South Africa poultry production is moving toward the 21st century with the potential for increased development being greater than any other sector of the agricultural industry. The small-scale to medium-scale or semi-commercial farmer is becoming a role-player that needs to be serviced by the poultry industry (Fourie, 2000). The industry will have to take up the challenges that are facing an entrepreneur starting with a poultry venture. The poultry industry has developed from a humble beginning at the turn of the century into a multi-million Rand enterprise where protein is provided through the commercial and small marketing sector (Fourie, 2000). Some of the larger commercial companies market three million birds per week. It is estimated that the commercial company sector is responsible for 75 to 85 percent of production and marketing of white meat in this country whereas the small-scale and medium-scale or semi commercial poultry production enterprises provide 20 to 25 percent of the white meat through the sales of slaughtered and live poultry sale to rural, peri-urban and urban settlements (Fourie., 2000). Small-scale and semi-commercial broiler production is developed by entrepreneurs who buy day-old chicks from the big commercial hatcheries, rear them to the age of five to eight weeks and sell them through a marketing network or small outlets. The small-scale consist of farmers who reared 100 t0 1000 chickens per batch and semi-commercial consist of farmers who reared 1000 to 5000 chickens per batch. These types of farmers acquire very little technical backup in terms of a training and services center where assistance is available every day of the week. The broiler industry requires birds that are of commercial crosses selected for their ability to grow very fast and produce a good quality carcass in the shortest time frame. The small farmers purchase broiler stock, as the day-old chicks from commercial hatcheries and reared them up to six to eight weeks before slaughtered or sold as live chickens. The selling of live chickens through a network outlets system is becoming an industry that is growing at a steady pace, as household food security is becoming important to communities (Fourie, 2000). The price of feed is the single most expensive item on the list of expenses of a farmer because of their financial constraints. The small-scale and semicommercial broiler farmer is faced with the problem of buying small quantities of feed at an inflated price. The problem can be alleviated by groups of small farmers joining co-operative and buying feeds in bulk from suppliers and redistributing to small farmers. The community co-operative can once again play a major role in the distribution of small amounts of feed to its member. The biggest challenge is to provide training with a “hands on” approach. It will be ideal to have a training center where small farmers can be trained in all aspects of poultry production. The training facility will have to operate as a fully operational poultry unit with no risks to bio-security of a commercial enterprise. Training will have to be provided in aspects like hatchery, housing, broilers and record management depending on the farmer’s needs. There is also a need for the research on broiler performance under small-scale and semi commercial farming. Research in this sector of poultry production should look in appropriate feeds, feeding, technology, genotype and performance of genotypes under the system. Emphasis in this study will be on growth patterns and performance of the Ross hybrids as a modern broiler under small-scale and semi commercial management condition. Aspect of the environment such as age, type of feeds and feeding methods, housing, seasons, lighting and genotype will be taken into consideration. The result of the study will provide a realistic database for mathematical modeling of production response and guideline for management planning in small-scale and semi-commercial management condition. Also this result will be important to broiler breeders, to determine the suitability of the modern broiler to small-scale and semi commercial management conditions. The objective of the study was to evaluate the mathematical model that could describe the performance of broilers under the small-scale and semi-commercial management conditions.

Introduction: In the Northern region of the Northern Province, there is an increase in the number of small-scale and semi-commercial farms in all sectors of agriculture. This includes the production of grains, vegetables, fruits and livestock. Broiler production seemed to be a much-preferred alternative of development in community based projects and emerging farmers have shown keen interest. This is because broiler production requires less space than ruminants and is ready for human consumption within a very short period of time. Poultry production provides a constant source of income and protein with a big customer demand. By the year 2000, broiler production is expected to reach 4000 million and 7.5 million tons of poultry feeds in the world. Many countries have initiated programs aimed at improving small-scale poultry as a means of helping to bring socio- economic benefits to rural communities (Panda, 1989). In order to feed the ever rising population of 4.9 million in the Northern Province (1996 Census), there must be an increase in the production of broilers as a primary source of top quality animal protein. With the high unemployment rate (46%) in the Northern Province, self- employment projects are needed which comply with agro- processing. More than 90 community projects based on poultry production in the Northern region of the Northern Province had been established in order to reduce the high rate of unemployment. Today more people have engaged themselves in community projects especially in poultry production than ever before. Some of the constrains of broiler production at both small-scale and semi-commercial farming condition includes inadequate ventilation system. Lack of suitable health care facilities and frequently the absence of efficient marketing structures form part of the obstacles to the rapid development of poultry production. Feed costs which remain the highest input cost in the production of broilers represent between 60 to 70% or more of the total costs of broiler productions (Benyi and Habi, 1998). Lack of management skills and training for small and semi-commercial farmers makes it difficult to obtain optimum performance. The objective of this study is to evaluate the performance of broilers as influenced by environmental factors under small.

Commercial broiler chickens were reared as combined sexes at floor space areas of 0.6, 0.7, 0.8, 0.9 and 1.0 ft.2 per bird to ten weeks of age. There was no significant difference in the mean body weights at nine weeks of age. At ten weeks of age, there was no significant difference in the mean body weights of the birds reared at 0.7, 0.8, 0.9 and 1.0 ft.² per bird, while the floor area of 0.6 ft.² per bird produced significantly lighter birds than did 1.0 ft.² Mortality was not affected by bird density, whereas the percentage of breast blisters increased with increasing density. Broiler production costs and various combinations of feed and meat prices were used in models to determine the age at which maximum annual net returns per square foot of floor area occurred. Assuming that the weekly mean body weights were the same for birds grown at 0.7 and 1.0 ft.² per bird floor area, maximum net returns were obtained by marketing at nine or ten weeks of age depending on feed and meat prices. The effect on net returns of marketing one week earlier or later than at the age of greatest net returns was examined. When it was assumed that the number of lots per year was limited to 4.33 i.e. a twelve week replacement program, annual maximum net returns were found to occur at a market age of at least ten weeks. When the number of lots marketed was not assumed to be limited, annual maximum returns also occurred, with few exceptions, at least at ten weeks of age. / Land and Food Systems, Faculty of / Graduate

The major source of calcium for the developing chick embryo is the eggshell. However, the actual mechanism of calcium solubilization from the shell is unknown. The temporal correlation of carbonic anhydrase activity to calcium movement implies that an acidic environment is essentail. To clarify the role of carbonic anhydrase in calcium solubilization and uptake by the chorioallantoic membrane of the chick embryo treatment effects on embryo development, carbonic anhydrase activity and calcium and pH levels were investigated. The treatments consisted of solutions of acid, base, calcium and strontium chlorides, and the enzyme inhibitor-acetazolamide.Experimental sampling was conducted from eleven to sixteen days of incubation. The treatments were administered daily by dipping the eggs into a treatment solution with subsguent sampling on the following day. The acid treatment solution produced a significant (P≤0.05) increase in calcium solubilization and a decrease in carbonic anhydrase activity from the control levels. The base treatment solution produced a significant decrease in calcium solubilization and an increase in carbonic anhydrase activity from the control levels. The calcium chloride treatment solution (providing a partial source of a calcium non-carbonate compound) and the strontium chloride treatment solution (providing a partial source of a non-calcium non-carbonate compound) showed no overall effect on embryonic calcium concentrations. However, there was a decrease in carbonic anhydrase activity from that of the control. This decrease did not appear to be due to a calcium mediated process but was more sensitive to changes in bicarbonate or carbonate levels. Treatments with acetazolamide demonstrated that there was a decrease in carbonic anhydrase activity and also a decrease in calcium transported. However, when an acid treatment was combined with the acetazolamide treatment, calcium was transported even though carbonic anhydrase activity was greatly suppressed. These results confirm that carbonic anhydrase activity appears to be fimctioriing in calcium solubilization and maintenance of the embryonic acid-base balance. It does not appear that the enzyme functions primarily in the transport of calcium across the chorioallantoic membrane. / Land and Food Systems, Faculty of / Graduate

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Thesis (Ph. D.)--Mississippi State University. Department of Poultry Science. / Title from title screen. Includes bibliographical references.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xvii, 275 p.; also includes graphics (some col.) Includes bibliographical references (p. 239-275). Available online via OhioLINK's ETD Center

Thesis (M.S.)--Brigham Young University. Dept. of Physiology and Developmental Biology, 2006. / Includes bibliographical references (p. 49-52).