Research on ascites occurring in meat-type chickens reared at moderate and low altitude has shown that the pathogenesis is similar to that of the high altitude disease. Pulmonary hypertension (PH) caused by increased blood flow or increased resistance to flow in the lung results in right ventricular hypertrophy (RVH), valvular insufficiency, increased venous pressure and ascites. The structure of the avian heart, with its thin-walled right ventricle and muscular right atrioventricular valve, allows PH to induce heart failure quickly. The sudden increase in pulmonary hypertension syndrome (PHS) in meat-type chickens in the 1980s was associated with a rapid increase in growth rate and feed conversion. This was a result of a combination of genetic selection for fast-growing, heavy broilers with low feed conversion and a more dense, high caloric, pelleted food that supplied all the nutrients required for rapid growth and encouraged a high nutrient intake. PHS in meat-type chickens is usually primary pulmonary hypertension, that is, PH that occurs without evidence of prior heart or lung disease that could account for the increase in blood flow or resistance to flow that results in the increased pressure in the pulmonary arteries. The lungs of birds are firm and fixed in the thoracic cavity and they do not expand to draw air into the lung. The blood and air capillaries form a rigid network that allows only minimal expansion of the blood capillaries when more blood flow is required. Air is moved through the lung by abdominal movement which draws air in and out of the air sacs. The anatomy and physiology of the avian respiratory system are important in the susceptibility of meat-type chickens to PHS. The small stature of the modern meat-type chicken, the large, heavy breast mass, the pressure from abdominal contents on air sacs, and the small lung volume compared to body weight, may all be involved in the increased incidence of PHS. There is limited space for blood flow in the avian lung. Factors that increase blood flow or increase resistance to flow are additive. Increased blood viscosity caused by the polycythaemia of hypoxia, or increased erythrocyte rigidity of high Na (+), are more likely to produce PH in fast-growing than in slow-growing birds. Increased flow due to cold exposure is also additive. Ascites caused by PH is a production-related disease at low altitude. It can be prevented easily by restricting growth rate. It is possible that some meat-type chickens of the phenotype we have created have reached the limit of blood flow through their lungs and that future improvements in growth rate will only be possible if the lung and abdominal cavity capacities are enlarged.

https://www.tandfonline.com/doi/pdf/10.1080/03079459308418934

Ascites in poultry

Disclosed is a process for growing the microflora Thraustochytrium, Schizochytrium and mixtures thereof, which includes the growing of the microflora in fermentation medium containing non-chloride containing sodium salts, in particular sodium sulfate. In a preferred embodiment of the present invention, the process produces microflora having a cell aggregate size useful for the production of food products for use in aquaculture. Further disclosed is a food product which includes Thraustochytrium, Schizochytrium, and mixtures thereof, and a component selected from flaxseed, rapeseed, soybean and avocado meal. Such a food product includes a balance of long chain and short chain omega-3 highly unsaturated fatty acids.

Process for the Heterotrophic Production of Microbial Products with High Concentrations of Omega-3 Highly Unsaturated Fatty Acids

In humans, metabolic complaints may be associated with a failure in one of the body hormone or enzyme systems, a storage disease related to lack of metabolism of secretory products because of the lack of production of a specific enzyme, or the breakdown or reduced activity of some metabolic function. Some of these disorders also occur in poultry, as do other important conditions such as those associated with increased metabolism, rapid growth or high egg production that result in the failure of a body system because of the increased work-load on an organ or system. These make up the largest group of poultry diseases classified as metabolic disorders and cause more economic loss than infectious agents. Poultry metabolic diseases occur primarily in two body systems: (1) cardiovascular ailments, which in broiler chickens and turkeys are responsible for a major portion of the flock mortality; (2) musculoskeletal disorders, which account for less mortality, but in broilers and turkeys slow down growth (thereby reducing profit), and cause lameness, which remains a major welfare concern. In addition, conditions such as osteoporosis and hypocalcaemia in table-egg chickens reduce egg production and can kill.

Production and growth related disorders and other metabolic diseases of poultry – A review

An imbalance in the human dietary intake of various types of fatty acids has become apparent. Results of fundamental studies have shown specific and beneficial effects on human health and well-bein...

Manipulation of the n-3 polyunsaturated fatty acid composition of avian eggs and meat

n-3 enrichment of chicken meat using fish oil: alternative substitution with rapeseed and linseed oils

The effect of dietary HM on plasma and egg yolk lipids of commercial White Leghorn hens was studied over 350 d. A total of 192 birds were given corn-wheat-soybean meal diets that contained either 0, 4, 8, or 12% HM. Analysis of plasma lipids at four periods in the laying cycle (169, 211, 253 and 287 d) and at five times during the test day (0800, 1000, 1200, 1400 and 1600 h) were performed. Egg lipids were analyzed at each of the four periods.Plasma total lipids were inversely related (P < 0.01) to dietary HM levels while omega-3 and omega-6 fatty acid levels were positively and inversely related (P < 0.001), respectively. HM levels did not influence the total lipid content of the egg yolk lipids but omega-3 and omega-6 fatty acid content were positively and inversely related, respectively. The levels of eicosapentaenoic (20:5n3, EPA) and docosahexaenoic (22:6n3, DHA) acid were 11 and 3 times higher, respectively (7.8 and 100.5 mg yolk−1) in the yolks from hens given the 12% HM diet compared to the contro...

The effect of dietary herring meal on the omega-3 fatty acid content of plasma and egg yolk lipids of laying hens

The Effects of Different Dietary Fat Sources on General Performance and Carcass Fatty Acid Composition of Broiler Chickens

The effect of dietary menhaden meal (MM) on production and egg yolk lipids of commercial White Leghorn hens was studied for 350 d. One hundred and ninety-two birds were given a corn-wheat-soybean diet that contained either 0, 4, 8, or 12% MM. Analysis of the egg yolks at four periods in the laying cycle (162, 211, 254, and 289 d) was performed on the fresh and stored (4 wk at 4 °C, ) egg yolks. Sensory evaluation was performed on fresh eggs collected at the end of the laying cycle (448 d).Production whether measured as hen-day or hen-housed, increased linearly with the inclusion of MM in the diets. The level of eicosapentaenoic and docosahexaenoic acids increased 10- and 2.6-fold to give levels of 9 and 95 mg yolk−1, respectively. Storage had no effect (P > 0.05) on these parameters. Sensory data suggested that the level of MM in the diets of laying hens should be between 4 and 8% in order to avoid off-flavours in eggs. Key words: Menhaden meal, laying hens, omega-3 fatty acids, storage, eicosapentaenoic ...

The effect of dietary menhaden meal and storage on the omega-3 fatty acids and sensory attributes of egg yolk in laying hens

Pink Discoloration in Cooked Broiler Chicken

Five dietary levels of sodium chloride (0.2, 0.4, 0.6, 1.0 and 1.8%) were used. Commercial broiler chickens tolerated 0.4–1.0% of dietary sodium chloride without adverse effects on performance. Key words: Broilers, salt, diets, sodium chloride

D. M. Nash

Papers

The effect of dietary herring meal on the omega-3 fatty acid content of plasma and egg yolk lipids of laying hens

The Effects of Different Dietary Fat Sources on General Performance and Carcass Fatty Acid Composition of Broiler Chickens

The effect of dietary menhaden meal and storage on the omega-3 fatty acids and sensory attributes of egg yolk in laying hens

Pink Discoloration in Cooked Broiler Chicken

Effects of a wide range of dietary salt levels on the performance of broiler chickens