Hybrid striped bass (Morone chrysops x M. saxatilis) aquaculture is a major commercial enterprise in the United States and internationally. Efforts to decrease diet costs and limit dependence on fishmeal, have led to the development of plant-based diets as an alternative aquafeed. Due to limiting concentrations of amino acids such as methionine, cystine, and taurine in plant meals such as soybean meal, supplementation of these plant-based diets with methionine or other sulfur amino acid compounds is typically required. Therefore, the current study was conducted to evaluate different amino acid supplements in soybean-meal-based diets for hybrid striped bass for possible refinement of diets and reduction of production costs. One feeding trial evaluated methionine hydroxy analog (MHA) and Mintrex® which is MHA containing chelated zinc relative to L-methionine. The second trial evaluated the effects of supplemental taurine or arginine on fish performance and potential health benefits. In the first feeding trial, a basal soybean-meal-based diet (56% soybean meal and 15% fishmeal) marginally deficient in total sulfur amino acids (TSSA) (1.10% methionine and cystine) was supplemented with either L-methionine, Mintrex® or MHA calcium salt and fed to triplicate groups of juvenile hybrid striped bass for 10 weeks. The different methionine supplements provided similar weight gain, feed efficiency ratio (FER) and protein efficiency ratio (PER) values that tended to be greater than observed in fish fed the basal diet. Mintrex® supplementation provided much higher plasma zinc concentrations compared to fish fed the other methionine supplements. In the second feeding trial, soybean-meal based diets which satisfied the requirement for TSAA were supplemented with either taurine or arginine at 1.5% of dry weight. Supplemental taurine or arginine did not provide any improvements in weight gain, FER, PER or survival compared to the basal diet. Thus, taurine or arginine supplementation of soybean-meal-based diets does not appear warranted. However, sulfur amino acid supplementation of plant-based diets is critical, and Mintrex® appears to be an effective supplement to meet the methionine and zinc needs of hybrid striped bass.

In the first of three experiments, four Holstein multiparous dairy cows, equipped with ruminal and duodenal cannulas, were used to determine the impact of different methods of treating soybean meal (SBM) on ruminal degradability and intestinal digestibility of CP and amino acids (AA). Solvent extracted SBM (SE), expeller SBM (EP), lignosulfonate SBM (LS) and heat and soy hulls SBM (HS) were incubated in the rumen, in nylon bags, for various intervals up to 48h. Additional samples incubated for 16 h were pre-treated with pepsin HCI, and then used for determination of intestinal digestibility either in situ (mobile bag technique) or in vitro. Treatment of SBM (EP, LS, HS) increased rumen undegradable protein (RUP), and AA availability in 30%. Estimates of intestinal digestibility of AA and CP were lower when measured in vitro than in situ. Among the treated SBM products, four EAA (Ile, Leu, Phe and Val) showed differences in availability, with values consistently lower for HS than for LS. The second experiment involved a comparative assessment of the availability of lysine in SE and rumen protected SBM products (EP and LS). Lysine availability was assessed either by the increment in plasma flux of 15N lysine, the increment in intestinally digestible lysine (using chromic oxide as a digesta marker) or by the use of a "plasma lysine response curve" designed to predict intestinally available lysine. The plasma Lys flux was not different between the different SBM products. However, SE + 70 g.d-1 omasal infusion of Lys (SE70) increased Lys flux by exactly 70 g.d -1 above the SE treatment. No differences were observed on duodenal Lys flow, post-ruminal digestion and digestible Lys between the SBM diets (SE, EP, LS). Irrespective of the method of assessment, lysine availability was not altered by the method of treating SBM. The third study evaluated the relative impact of supplying rumen-undegraded protein (RUP) versus altering the carbohydrate source on milk yield and efficiency N usage for milk production. Protein supplementation (SE and EP) increased DMI, whereas the inclusion of beet pulp (BP) replacing 50% of high moisture shelled corn decreased DMI. The results of this research suggest that, under normal conditions of feeding, supplying rumen protected SBM to enhance the supply of intestinally available essential AA does not improve lactation performance; providing beet pulp as a source of readily fermentable fibre also failed to affect milk yield or efficiency of N usage for milk production by dairy cattle.

The objective of this dissertation was to evaluate the effects of exogenous enzymesupplementation to gestation-lactation diets on the digestibility of nutrients in mature swinefemales and the associated implications on energy metabolism during gestation and lactationphysiologic states. Three experiments were performed to evaluate the effects of commerciallyavailable enzyme products or pure enzymes on the digestibility of nutrients. Crossover designs intwo periods during gestation (early and late gestation) and lactation were studied to obtain anincreased number of observations from the surgically cannulated sows.Experiment 1 evaluated the effects of two enzyme products supplemented to a practicalcorn soybean meal diet fed to second parity crossbred sows. One of the enzyme productscontained both protease and cellulase activities, and the other xylanase activity, both productswere produced by microbial fermentation. No effects (P andgt; 0.10) were observed during eitherperiods during gestation. During lactation, effects of both enzyme products were observed fordigestibility of nutrients. Protease/cellulase supplementation increased ileal digestibility of grossenergy (P andlt; 0.09). Xylanase supplementation produced higher ileal digestibilities of dry matter,nitrogen and gross energy (P andlt; 0.02), improvements that were maintained for the total tractdigestibilities (P andlt; 0.05).Experiment 2 evaluated pure exogenous enzymes added to a practical corn soybean mealdiet fed to multiparous crossbred sows. Alpha-galactosidase and protease were supplementedeither alone or in combination to a control diet and compared to a non-supplemented diet duringperiods in gestation and lactation. The observed increases in ileal digestibilities in lactation inExperiment 1 for dry matter, nitrogen and gross energy were observed as tendencies (P andlt; 0.15)during lactation on Experiment 2.Experiment 3 evaluated a semipurified diet (with soybean meal as the only proteinsource) supplemented or not with an enzyme product containing protease and cellulase activitiesfrom microbial fermentation. Multiparous crossbred sows were fed the semipurified diet for twoperiods during gestation and two weeks during lactation. Effects of the enzyme product (P andlt;0.10) on nutrient digestibility were observed during gestation. Apparent digestibilities ofnitrogen were greater for the supplemented diet. In addition, there were observed tendencies (P andlt;0.15) for higher ileal digestibilities of dry matter and gross energy for the supplemented dietduring gestation. No effects (P andgt; 0.10) were observed during lactation period for any of theresponse variable tested. However, tendencies (P andlt; 0.15) of higher DM and GE total tractdigestibilities were observed in lactation for the supplemented diet.According to the results observed in the three experiments, the supplementation ofexogenous enzymes to gestation and lactation diets has the potential to increase the ilealdigestibilities of dry matter, nitrogen, and gross energy, especially during the lactation period.

The objective of these studies was to determine the optimum standardized ileal digestible tryptophan to lysine (SID Trp:Lys) ratio for growing pigs fed both U.S.–type (corn–soybean meal) and non–U.S.–type (wheat–barley) diets. When feeding U.S.–type diets, average daily gain (ADG) and plasma urea nitrogen (PUN) concentrations improved as SID Trp:Lys ratios increased, yielding optimum ratios of 15.32% (P<0.001) and 15.25% (P<0.001), respectively. Averaging these resulted in an optimum SID Trp:Lys ratio of 15.29%. In non–U.S.–type diets, feeding increasing SID Trp:Lys ratios improved ADG and PUN, displaying optima of 15.99% (P=0.048) and 15.29% (P=0.054), respectively. This produced an average optimum SID Trp:Lys ratio of 15.64%. The final study included the other dietary essential amino acids (EAA) at a higher level, and ADG and PUN improved as SID Trp:Lys ratios increased, yielding optima of 17.93% (P<0.001) and 16.17% (P=0.009). This averaged to an optimum SID Trp:Lys ratio of 17.05%. Overall, diet composition did not affect the Trp:Lys requirement of growing pigs, however, feeding the other EAA at higher levels resulted in a higher estimated optimum SID Trp:Lys ratio. The optimum SID Trp:Lys ratio is estimated to lie between 15.29% and 17.05%.

This thesis examines the pricing efficiency of the Quebec corn and soybean meal markets to answer a hypothesis on the part of the local livestock industry as to the existence of pricing inefficiency in the feed input industry. In evaluating the pricing efficiency of the markets, this research used two approaches: an analysis of market and an analysis using econometric models, focusing on price information structure accuracy and rapidity. The weekly data series of corn and soybean meal price are from selected cities in Canada and the US cover the crop years of 1990--1996. / The accuracy is addressed by applying Faminow's model for testing the pricing systems and Houck's model for testing price transmission symmetry. The results showed that the Quebec corn market is accurate based on the evidence of (i) a relatively unconcentrated market structure; (ii) evidence of an FOB pricing system; and (iii) symmetric price adjustments. Even though the soybean meal market is also based on an FOB pricing system, it is not accurate because the price adjustments are asymmetric and its market structure is highly concentrated. / The rapidity is addressed by applying Vector Error Correction (VEC) models in three ways: (i) by investigating the cointegration relationships, (ii) by assessing the strength of the relationships, and (iii) by measuring dynamic price response. The results showed that the strength of the relationships and the speed of Quebec corn price adjustment in response to external shocks are less than those found in Ontario and Southeastern US markets, while soybean meal is comparable to those markets. / Thus, by means of an assessment of market structure, marketing margin, price information transmission accuracy and rapidity, this research concludes that the corn market in Quebec is relatively pricing efficient while the soybean meal market is not.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2004. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 171-174). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves 171-174). Also available on the Internet.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1944. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies: leaves 22-24, 70-73.

Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xvi, 105 p.; also includes graphics (some col.) Includes bibliographical references (p. 95-105). Available online via OhioLINK's ETD Center