Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 82-89). Also available on the Internet.

Please read the abstract in the section 00front of this document / Dissertation (MSc Agric (Pasture Science))--University of Pretoria, 2007. / Plant Production and Soil Science / unrestricted

Twenty-eight beef-type animals were divided into four groups and fed four rations consisting of equal amounts of basal ration, to which increments of alder sawdust (Alnus rubra) were added (0, 13%, 21%, and 35%) (Experiment I). The addition of the sawdust had no significant effect on total gain although the three groups of animals receiving sawdust in their diet had a higher rate of gain than the group receiving no sawdust. The effects of the ration on the carcass grade and the acceptability (tenderness and juiciness) of the meat as studied by a trained taste panel, were non-significant. When the rations used in the above trial were subjected to a digestion trial using mature wethers, the results coincided with the growth data collected from the steers used above. If the digestion of the basal rations were taken as constant, the wood material had a digestion coefficient ranging from 46.5% to 13.5%, depending on the level of sawdust in the diet. It was felt that a figure of 13% digestion for sawdust was close to being correct, and that the variation in measurement of the digestion of sawdust was due to the increased utilization of the basal ration when the sawdust was present. Analysis of the rumen fluid of the steers in the growth trial for total and individual volatile fatty acids (VFA) showed a decrease (p<.05) in the molar percent of propionic acid as the level of wood in the diet increased, while the total concentration of VFA and the molar percent acetic acid remained relatively constant. Thirty-six yearling Hereford steers, assigned to six treatments consisting of a basal ration and three roughage sources (hay (H), alder sawdust (W), and extruded alder sawdust (E)), fed at two levels (15% and 20%), were used in a study to determine the effect of heat and pressure treatment of wood on the utilization. The growth of the animals on the H rations was significantly (p< .01) greater than those on the other treatments. The effect of treating the sawdust by extruding it was non-significant although the animals on the extruded wood diet had a slight increase in gain over those on the W ration. The effect of level of roughage was nonsignificant. The effects of level of protein in the diet and the interaction with roughage source were studied. Protein levels of 13% and 15% were studied, along with two roughage sources (hay (H), and alder sawdust (W)), fed at two levels (15% and 20%). The H rations again had a significantly (p<.01) greater gain. The effect of increasing the protein level in the diet was found to be non-significant. When the above rations were subjected to analysis using the in vitro technique, results showed that the H rations had a significantly (p < .01) higher digestion than either the W or E rations. It was also found that the E rations had a higher digestion coefficient than the W rations (p <«05). Increasing the roughage level from 15% to 20% caused a significant (p<.01) decrease in digestion. When the same rations were subjected to an in vivo digestion study using growing wethers, the results were similar to the in vitro study with the H rations having a greater digestion (p <.01) than the W or E rations. However the difference between the W and E rations was non-significant. An equation for predicting the in vivo dry matter digestion is given: In vivo dry matter digestion = 60.1252 + 0.0221 (in vitro dry matter digestion) + 0.4799 (acid detergent fibre) - 3.5855 (lignin) - 0.8395 (cellulose). / Land and Food Systems, Faculty of / Graduate

Content and availability of nutrients in four vegetable protein supplements (palm kernel, soybean, cottonseed and rapeseed meals) were determined using growing chicks. Average availability of sixteen amino acids in these feedstuffs ranged from 84.5% (palm kernel meal) to 97.3% (soybean meal). Palm kernel meal was lowest and soybean meal highest in content of essential amino acids. Results of mineral availability (calcium, phosphorus, magnesium, manganese, zinc and copper) indicated high content and availability of calcium, phosphorus and magnesium; low content and availability of zinc and copper. Average availability of minerals varied from 50.0% (palm kernel meal) to 74.3% (soybean meal). Among mineral elements tested, phosphorus (78.0%) and calcium (72.6%) showed the highest availability while zinc (44.0%) was least available. Crude fibre and phytic acid were implicated as factors depressing availability of minerals tested. Crude fibre content was inversely related to availability of all six minerals tested while phytic acid content significantly (P^O.01) affected availability of phosphorus, calcium, zinc and magnesium. Metabolizable energy (ME) of the feedstuffs determined using three week old broiler chicks, ranged from 1957 kcal/kg dry matter (rapeseed meal) to 2796 kcal/kg dry matter (palm kernel meal). Chemical constituents, available carbohydrate and metabolizable energy content of seven different rapeseed meals were determined. Metabolizable energy values ranged from 1492 kcal/kg (Span A) to 1957 kcal/kg (commercial RSM). Of all chemical constituents tested, ether extract, sugar and starch content were most significantly (P«%0.01) related to metabolizable energy and were incorporated into equations to predict ME of rapeseed meal from their chemical constituents. Content and availability of six minerals (Ca, P, Mg, Mn, Zn, Cu) were determined using the test rapeseed meals. Samples were high in calcium, phosphorus and magnesium and low in copper in comparison to other vegetable protein supplements. Average availability of minerals ranged from 52.2% (Span A) to 64.0% (commercial RSM). Among minerals tested, phosphorus (75.3%), copper (74.3%) and calcium (68.0%) showed the highest availabilities. Zinc was least available (44.1%). Treatment of palm kernel meal with 3%, 5% or 7% NaOH in an attempt to delignify the material and improve its nutritive value, caused a reduction in protein, acid detergent fibre and acid detergent lignin content of the meal. There was considerable amino acid destruction, the extent being directly related to the severity of the alkali treatment. Incorporation of alkali-treated meal -at 30% level into broiler starter rations depressed growth rate and feed efficiency of chicks. Inclusion of palm kernel meal at 10%, 20% or 30% into a standard broiler starter diet significantly (P«»0.05) increased average daily gain of chicks over controls. Highest growth rate and feed efficiency were observed in chicks on the 10% PKM ration. Increased level of PKM incorporation slightly depressed feed efficiency but not growth rate of chicks. The need for increased utilization of vegetable protein supplements in chick rations especially in the developing countries was discussed. / Land and Food Systems, Faculty of / Graduate

In times of economic hardship, everyone must find ways to adapt, and the poultry industry is no exception. The majority of the cost in an integrated poultry operation is feeding the birds. Distillers dried grains with solubles (DDGS) has been around for decades as a by-product of the beverage industry and more recently as a co-product of the ethanol industry. Over the past decade, there has been a dramatic increase in the production of DDGS from U.S. ethanol biorefineries, making the co-product a very economical choice. DDGS have not held a common place in the poultry industry for long though, as issues with nutritional variability, storage, transportation, etc. all have led to the product being avoided by nutritionists much of the time. Even now, DDGS are fed at a relatively low inclusion level compared to other major feed ingredients such as corn, wheat and soybean meal. With the often volatile price of corn grain, DDGS are receiving more attention as a feasible alternative in commercial poultry diets as research, such as that presented in this dissertation, continues to elucidate the nutritional, economical and dietary inclusion aspects of this once neglected ingredient. The primary purpose of this research has been to determine the efficacy of DDGS as an ingredient in poultry diets, and also to further elaborate on the suitable inclusion rates in a ration. In the end it is clear that DDGS are an effective and suitable choice for inclusion into both broiler and layer diets. DDGS can be incorporated into layer diets at up to one-third of the ration with no deleterious effects on performance or egg quality. DDGS can be added to broiler diets at varying inclusion levels, depending on bird age, as the research points towards increased tolerance of the co-product as the bird ages, without harming bird health or performance. It is also shown that further processing of DDGS, primarily fiber separation, can have a positive effect on bird performance. In conclusion, DDGS inclusion in poultry rations is a sound choice provided attention is paid to the nutritional profile of this co-product.

No description available.

No description available.

No description available.

Note:

No description available.