AVAILABILITY OF ENERGY IN RENDERED BY-PRODUCTS USED IN POULTRY RATIONS
Title:AVAILABILITY OF ENERGY IN RENDERED BY-PRODUCTS USED IN POULTRY RATIONS
Principle Investigator: Jeffre D. Firman, University of Missouri
Year: 2000
Objective: To determine the energy availability of different animal by-product sources for turkeys and broilers.
Lay Summary/Industry Summary: Energy analysis of 12 samples of meat and bone meal and 15 samples of poultry by-product meal were conducted using turkeys, broilers and the leghorn rooster as the research animals. Each sample will be analyzed in three different fashions. The energy from these feces will be used to correct for fecal energy that would have been excreted regardless of the feed sample being fed. Both feed energy in and fecal energy out (corrected for endogenous loss) will be measured and TME calculated from the difference of these numbers. In the second series of experiments, a modified total collection will be done for determination of Apparent Metabolizable Energy (AME) and a longer term TME valuation. In these experiments, 3 wk old birds will be fed a basal diet and energy value determined. This basal diet will then be diluted (50%) by addition of the products being tested. Birds will be fed for 3 days on the test diet with total feed intake measured as well as total feces collection. Energy determination of feed and feces adjusted for the energy content of the basal ration will be used to determine AME.
Poultry meal samples ran at book values or somewhat lower. This is primarily due to the increased ash content and decreased fat content found in certain meals. Meals from many plants are showing changes in composition based on the carcass inclusion in the product. This is due to further processing of the chicken versus whole bird production of the past. The variety of assay methodologies utilized showed few differences (11 of 15 were similar) between procedures, indicating that any of the methods used are acceptable. This is as would be expected as each of the procedures should provide similar results. There was a tendency for turkey values to be slightly lower although statistical differences were not found.
Meat meal samples ran at book values or above. Improved processing procedures have probably improved digestibility in the recent past. Differences in procedure were found within samples in some cases. Generally this was manifested in lower values for chick digesta AME’s. Chick and turkey values for meat meal samples were very similar within samples.
Overall it appears that any energy analysis method is acceptable, although there were more differences in meat meal samples than in poultry meal samples. There were also few differences between chickens and turkeys in these samples.
Scientific Abstract: This project was designed to determine the energy availability of different animal by-product sources for turkeys and broilers. Energy analysis of 12 samples of meat and bone meal and 15 samples of poultry by-product meal were conducted using turkeys, broilers and the leghorn rooster as the research animals. Each sample will be analyzed in three different fashions (Zanella et al., 1999). The first of these will be the commonly used True Metabolizable Energy (TME) analysis based on the work of Sibbald (1986) and slightly modified for use in intact turkeys and cecectomized roosters. Briefly, birds will be denied access to feed for 36 hrs to clear the gut by being placed in digestibility cages. Each bird (8 replicates) will then be tube fed a quantity of feed equal to approximately 2% of body weight Feces will then be collected for 48 hrs post feeding. In addition, endogenous feces will be collected from a similar group of birds at the same time with all procedures identical with the exception of the tube feeding. The energy from these feces will be used to correct for fecal energy that would have been excreted regardless of the feed sample being fed. Both feed energy in and fecal energy out (corrected for endogenous loss) will be measured by bomb calorimetry and TME calculated from the difference of these numbers. In the second series of experiments, a modified total collection will be done for determination of Apparent Metabolizable Energy (AME) and a longer term TME valuation. In these experiments, 3 wk old birds will be fed a basal diet and energy value determined. This basal diet will then be diluted (50%) by addition of the products being tested. Birds will be fed for 3 days on the test diet with total feed intake measured as well as total feces collection. Energy determination of feed and feces adjusted for the energy content of the basal ration will be used to determine AME. In a modification of this procedure, birds will be pulled from feed at both the beginning and end of the trial for 24 hrs and endogenous excreta collected for a 24 hr period on day 1 and 3 of the trial. Endogenous loss will be estimated from these birds for the entire collection period and used for adjustment of the AME values. A minimum of 6 pens of birds will be used for each feed determination. The third method will be based on ileal digesta contents. Cromie oxide will be added to diets at .05% of the diet. Poults being fed the test diets will be killed with CO2 and ileal contents collected from Meckels diverticulum to the ileocolic juncture. Energy will be determined by the differences between cromic oxide concentration in diet and digesta. All data were analyzed for differences due to procedure as well as samples within procedures.
Poultry meal samples ran at published values or somewhat lower. The variety of assay methodologies utilized showed few differences (11 of 15 were similar) between procedures, indicating that any of the methods used are acceptable. This is as would be expected as each of the procedures should provide similar results. There was a tendency for turkey values to be slightly lower although statistical differences were not found.
Meat meal samples ran at published values or above. Improved processing procedures have probably improved digestibility in the recent past. Differences in procedure were found within samples in some cases. Generally this was manifested in lower values for chick digesta AME’ s. Chick and turkey values for meat meal samples were very similar within samples.
Overall it appears that any energy analysis method is acceptable, although there were more differences in meat meal samples than in poultry meal samples. There were also few differences between chickens and turkeys in these samples.