Economic Potentials of Poultry Breeding

One of the remarkable agricultural accomplishments of the past 30 years has been the increased productivity of our chickens. Not only has the poultry industry produced hens that would lay more eggs (national average, 1925-112, 1954- 183), but the economical production of meat in the form of broilerfryers has created a new industry in the poultry field. In attempting to analyze important factors contributing to these advances, it seems that three areas of improvement have been of major importance. Management (particularly as it relates to disease control and sanitation problems), breeding and selection, and improved rations have all contributed significantly to increased productivity. The purpose of this circular is to discuss methods used by geneticists to improve poultry by breeding and selection. In addition to reviewing some of the proven methods which resulted in recognizable improvement, unproven ones are included. It is out hope that after the poultryman reads this publication some of the unfamiliar terms that confront him can be more clearly understood and their importance evaluated. A glossary is included and may serve as a handy tool for defining technical or semitechnical terms

Feeding Systems for Layers

Numerous reports show there are many feeding systems for layers that the poultryman will find satisfactory. The important factor for good results is proper management of the feeding system. Essentially the most common feeding systems recommended and in use today are ( 1) all-mash, ( 2) 18-20 percent protein mash with limited or free-choice grain, and (3) 25-27 percent protein concentrate with free-choice grain. Some poultrymen have reported successful use of a 32 percent protein concentrate fed free-choice with grains. The laying hen has a remarkable ability to balance her own ration, but it has generally been felt that more concentrate is consumed than necessary •when a 32 percent protein concentrate is used. Before poultrymen started to use high energy feeds, all-mash rations were considered somewhat low in energy for maximum egg production-particularly during the winter. High energy all-mash diets should supply the extra energy needed for maintenance under cold weather conditions and therefore support production equal to that of the other systems. Many field reports indicate that some all-mash diets today are giving better results than the various mash and grain feeding systems. Here are some of the reasons poultrymen have again become interested in all-mash diets. 1) Bulk handling of feed has greater application where all-mash diets are used. Bulk handling of feed, in itself, appeals to many because of price discounts and the economy of handling costs. 2) All-mash feeds are more adaptable for use in mechanical feeders and cage-feeding operations. 3) Use of fats and oils in feeds to increase energy content finds greater application in all-mash feeds. The data in this circular were obtained from three experiments with heavy-type hens in which three feeding systems were compared. Also data obtained from use of a 20 percent protein mash and free-choice grain feeding system with various groups of layers are presented

Effects of Energy and Protein Levels and Antibiotics on Growing Turkeys

Much attention has been given recently to the use and value of high energy rations for poultry, particularly for broilers and to a limited extent for laying hens and young turkeys. Although the general fundamentals of the findings may appear applicable in formulation of diets for growing turkeys beyond the age of 8 weeks, little direct evidence has been available to justify such application. Actually, there is some evidence to indicate that the higher energy diets may not necessarily promote a more rapid rate of gain for the older birds. The current study considers the possible effects of protein and antibiotics on the problem

Reproductive Performance of Chickens as Influenced by Antibiotics in the Diet

Many workers have reported on the failure of antibiotic supplementation to improve the performance of hens already in high egg production. On the other hand, reports have appeared which indicated that under similar conditions the antibiotics have favorably affected the performances of laying pullets. The experiments of this study were designed to make it possible to determine effects of supplementation with antibiotics as well as to compare various feeding systems

Chemical Composition of Turkeys as it Affects Palatability and Keeping Quality

Turkeys produced on low and high energy diets were slaughtered for chemical analyses and taste panel evaluations before and after 6 months of frozen storage. Although the carcasses from groups fed the high energy diets were fatter than those fed the low energy diets, there were no differences in palatability scores for flavor, tenderness, and juiciness before or after storage. Likewise there were no consistent over-all preferences before or after storage. Neither were there consistent differences in fat peroxide levels after storage. The stored half-carcasses of toms showed no decline in palatability scores for flavor and tenderness whereas those of hens showed a decline. The toms showed higher juiciness scores than hens

Egg Marketing Losses in South Dakota

This bulletin attempts to answer the following questions: 1. What is the quality of farm eggs produced in this state? 2. Do eggs deteriorate in the South Dakota marketing channels? 3. What are the factors affecting quality of eggs and the decline of quality in the marketing channels? The data used here were obtained from two surveys. The main survey was conducted in 13 North Central states, including South Dakota, with the purpose of obtaining information on egg quality and quality deterioration in the marketing channel between first buyers and wholesale plants. To that end, buyers and wholesalers were interviewed and their marketing methods analyzed; eggs were candled and graded by a federal-state grader at the buyers\u27 stations and at the wholesale plants. This survey was conducted in 1948. Some data on the operations of the large wholesale plants and the stations refer to 1947

Kaon and Antikaon Production in Heavy Ion Collisions at 1.5 AGeV

At the Kaon Spectrometer KaoS at SIS, GSI the production of kaons and antikaons in heavy ion reactions at a beam energy of 1.5 AGeV has been measured for the collision systems Ni+Ni and Au+Au. The K-/K+ ratio is found to be constant for both systems and as a function of impact parameter but the slopes of K+ and K- spectra differ for all impact parameters. Furthermore the respective polar angle distributions will be presented as a function of centrality.Comment: 4 pages, 4 figures, SQM2001 in Frankfurt, Sept.2001, submitted to Journal of Physics

Local heat transfer coefficients at the inlet of an annular flow passage

Annular flow geometries are commonly found in several heat exchange devices, however, relatively little experimental work has been done specifically to determine the local heat transfer coefficients in developing flow in annuli. In this experimental study circumferentially averaged local heat transfer coefficients were determined with water for a uniform heat flux boundary condition on the inner wall in a horizontal concentric annular test section with a length of 1.05 m, a hydraulic diameter of 14.8 mm, and a diameter ratio of 0.648. Local inner wall temperatures were obtained via liquid crystal thermography with the aid of an automated camera position system. Conventional on-centre and off-centre annular inlet configurations with three inlet sizes were evaluated for Reynolds numbers ranging from 2000 to 7500. It was found that the local heat transfer coefficients were significantly higher at the inlet, and decreased as the boundary layers developed. Local maximum and minimum heat transfer coefficients were identified which may be due to flow impingement caused by the inlet geometry. A new local heat transfer correlation for the turbulent flow in regions close to the inlet of an annular flow passage was developed.The National Research Foundation of South Africahttp://www.elsevier.com/locate/ijhmt2018-10-30hj2017Mechanical and Aeronautical Engineerin