Chronic leptin administration increases serum NEFA in the pig and differentially regulates PPAR expression in adipose tissue.

Two in vivo studies were conducted with pigs to determine the effects of exogenous leptin on the expression of peroxisome proliferator activated receptors (PPAR), and on serum concentrations of selected metabolites and hormones. Initially, leptin was administered i.m.

The regulation of IGF-1 by leptin in the pig is tissue specific and independent of changes in growth hormone.

A combination of in vivo and in vitro experiments were performed to determine the extent to which exogenous leptin regulates serum growth hormone (GH) and insulin-like growth factor I (IGF-1) concentrations, and the abundance of IGF-1 mRNA in major peripheral tissues. Initially (Experiment 1), a recombinant human leptin analog was administered i.m.

Phytase, high-available-phosphorus corn, and storage effects on phosphorus levels in pig excreta.

Phosphorus-based land application limits for manure have increased the importance of optimizing diet P management and accurately characterizing the bioavailability of manure P. We examined the effects of pig (Sus scrofa) diets formulated with high-available-P corn and phytase on P levels in excreta and slurry stored for 30, 60, 90, 120, and 150 d. Twenty-four pigs (approximately 14 kg each) were fed one of four low-P diets: (i) normal corn, no phytase (control); (ii) normal corn with 600 phytase units kg(-1) (PHY); (iii) high-available-P corn, no phytase (HAP); and (iv) high-available-P corn with 600 phytase units kg(-1) (HAP + PHY).

Transport of putrescine across duodenal, jejunal and ileal brush-border membrane of chicks (Gallus domesticus).

Luminal polyamines and their absorption are essential for proliferation of the enterocytes and, therefore, nutrition, health and development of the animal. The transport systems that facilitate the uptake of putrescine were characterized in chick duodenal, jejunal and ileal brush-border membrane vesicles prepared by MgCl2 precipitation from three-week-old chicks. An inwardly-directed Na+ gradient did not stimulate putrescine uptake and, therefore, putrescine transport in chick intestine.

Additivity and associative effects of metabolizable energy and amino acid digestibility of corn, soybean meal, and wheat red dog for White Pekin ducks.

The additivity of true amino acid digestibility (TAAD) and true metabolizable energy (TME) values in corn, soybean meal, and wheat red dog for White Pekin ducks was investigated. Differences between observed values for the complete diets and values predicted from measurements of individual ingredients were used to test additivity. Eight ducks were each assigned to the following dietary treatments: corn, soybean meal (44% CP), wheat red dog (wheat by-product with less than 4% fiber), complete Diet 1 (corn-soybean meal), complete Diet 2 (corn-red dog-soybean meal), and dextrose.

Addition of enzyme to starter and grower diets for ducks.

The growth performance and nutrient utilization responses of White Pekin ducks to a commercial enzyme preparation were investigated. The enzyme contained 4,000 units amylase, 12,000 units protease, and 1,600 units xylanase per gram. Twelve pens of 10 ducks were fed diets based on corn and soybean meal and wheat middlings.

Quantification of digesta flow into the caeca.

1. A caecal intubation technique was developed to determine the amount of digesta that enters the caeca of fed and feed-deprived chickens. 2.

Postnatal ontogeny of kinetics of porcine jejunal brush border membrane-bound alkaline phosphatase, aminopeptidase N and sucrase activities.

Our objectives were to determine postnatal changes in the maximal enzyme activity (V(max)) and enzyme affinity (K(m)) of jejunal mucosal membrane-bound alkaline phosphatase, aminopeptidase N and sucrase using a porcine model which may more closely resemble the human intestine. Jejunal brush border membrane was prepared by Mg(2+)-precipitation and differential centrifugation from pigs of suckling (8 days), weaning (28 days), post-weaning (35 days) and adult (70 days) stages. p-Nitrophenyl phosphate (0-8 mM), L-alanine-p-nitroanilide hydrochloride (0-28 mM) and sucrose (0-100 mM) were used in alkaline phosphatase, aminopeptidase N and sucrase kinetic measurements.

Impact of betaine on pig finishing performance and carcass composition.

Two experiments were conducted to evaluate the effect of betaine supplementation of finishing diets on growth performance and carcass characteristics of swine. Experiment 1 included 288 pigs in a 2 x 2 x 3 factorial arrangement of treatments consisting of barrows and gilts of two genetic populations fed diets with 1.25 g/kg supplemental betaine from either 83 or 104 kg to 116 kg and control pigs fed betaine-devoid diets.

Additivity and associative effects of metabolizable energy and amino acid digestibility in barley and canola meal for White Pekin ducks.

An experiment was conducted using the TMEn bioassay method to investigate the additivity and associative effects of metabolizable energy and amino acid digestibility in barley and canola meal for White Pekin ducks. Additivity was tested by comparing the difference between observed values determined in a complete diet and predicted values from measurements determined with individual ingredients (barley and canola meal). Six ducks each were assigned to diets of barley, canola meal, the complete diet, and dextrose.

Effect of environment on the free and peptide amino acids in rice, wheat, and soybeans.

Controlled environments (CE) in which light, carbon dioxide, and nutrients are regulated are known to affect the chemical composition of plants. Controlled Ecological Life Support System (CELSS) environments are required for a Mars or lunar base where food resupply is both impractical and risky. Astronauts in a CELSS would need to grow and process edible biomass into foods.

Phosphorus bioavailability, growth performance, and nutrient balance in pigs fed high available phosphorus corn and phytase.

Three experiments were conducted to evaluate P bioavailability, growth performance, and nutrient balance in pigs fed high available P (HAP) corn with or without phytase. The bioavailability of P in normal and HAP corn relative to monosodiumphosphate (MSP) for pigs was assessed in Exp. 1.

The effects of tannins on nutrient utilisation in the White Pekin duck.

1. Two experiments were conducted to determine the effects of tannins on nutrient utilisation in the White Pekin duck. 2.

Methodological aspects of measuring amino acid uptake in studies with porcine jejunal brush border membrane vesicles.

With L-glutamine, as a representative amino acid this study was undertaken to examine the effects of substrate concentrations on initial and equilibrium amino acid uptake and intravesicular volume determined with porcine jejunal brush border membrane vesicles prepared by Mg2+-aggregation and differential centrifugation. Transport measurements (24 degrees C) were conducted by the rapid filtration manual procedure. Glutamine uptake was shown to occur into an osmotically-active space ranging between 1.

Ontogenetic development of intestinal digestive functions in White Pekin ducks.

The ontogenetic development of intestinal digestive functions for avian species other than the domesticated chicken are not well documented. Therefore, this study was conducted to resolve the developmental patterns of some intestinal digestive functions in White Pekin ducks. The ducks were killed and their intestines harvested when they were 1, 3, 5 and 7 wk old.

The influence of cecectomy on metabolizable energy and amino acid digestibility of select feedstuffs for white Pekin ducks.

Twenty-four cecectomized and 24 intact White Pekin ducks were used in two experiments to assess the influence of cecectomy on ME and amino acid digestibility of several feed ingredients for ducks. Corn and soybean meal (SBM) were evaluated in Experiment 1, and bakery meal (BM), red dog (RD), and wheat middlings (WM) were evaluated in Experiment 2. Nitrogen-corrected true metabolizable energy and amino acid digestibility of the ingredients were assayed concurrently.

Nutrient management procedures to enhance environmental conditions: an introduction.

The advent of concentrated, large animal production units presents a monumental challenge for the effective management of nutrients in animal manure. This symposium was organized to address the issue of the environmental impact of animal production and to offer suggestions on nutrient management procedures for reducing the environmental impact. There were four presentations on environmental concerns of animal manure that covered the topics of using the severe Dutch legislation that limits the amounts of nitrogen and phosphate in the manure allowed for application on cropland, potential for reducing odorous compounds in swine manure, alternatives to reduce the environmental impact of large swine production units, and, finally, perspectives on nutrient management procedures from a swine integrator's viewpoint.

Microbial phytase in finisher diets of White Pekin ducks: effects on growth performance, plasma phosphorus concentration, and leg bone characteristics.

Two experiments (Exp.) were conducted to determine the growth response of White Pekin ducks to inclusion of microbial phytase in finisher diet. In Exp.

Kinetic analysis of L-glutamine transport into porcine jejunal enterocyte brush-border membrane vesicles.

L-Glutamine transport into porcine jejunal enterocyte brush border membrane vesicles was studied. Uptake was mediated by a Na(+)-dependent and a Na(+)-independent pathway as well as by diffusion. The initial rates of glutamine uptake over a range of concentrations is both Na(+)-gradient and Na(+)-free conditions were analyzed and kinetic parameters were obtained.

Nutritional evaluation of two agroindustrial by-products for ducks and pigs.

Forty-eight male White Pekin ducks and 24 crossbred barrows (Landrace or Yorkshire sows; PIC Line 355 boars) were used in three experiments to evaluate the nutritional value of two by-products generated from agricultural industries. In each experiment, test ingredients consisted of a dried meat solubles product (DMS) from swine processing facilities and a yeast fermentation product (YFP) from a commercial source. Soybean meal (SBM) with a CP content of 48% served as the control ingredient in the three experiments.

Bioavailability of tryptophan in soybean meal and tryptophan retention in the carcasses of four-week-old ducks.

The objectives of the experiment were to determine the bioavailability of tryptophan in soybean meal for 4-wk-old ducks using the slope-ratio bioassay with L-tryptophan as the reference diet and estimate the efficiency of dietary tryptophan retention in the carcasses of 4- to 7-wk-old ducks. An initial representative group of 12 ducks with an average body weight of 1,951 g (SD = 69) were killed for carcass compositional analysis. A basal diet formulated to contain 1.

Changes in pars esophageal tissue appearance of the porcine stomach in response to transportation, feed deprivation, and diet composition.

Experiment 1 used 48 pigs to evaluate the effect of diet particle size, fat content, and a 24-h fast (FST) on pars esophageal (PE) tissue damage. Following a FST, a 750-microm, 550-microm, or 550-microm diet with 7.9% added fat was fed for 28 d.

Erythrocyte membrane digoxin-sensitive (Na(+)-K+)-ATPase of non-insulin dependent diabetic humans.

Erythrocyte plasma membranes of non-insulin dependent diabetic humans (NIDDM) and healthy humans were prepared by hypotonic lysis. The specific activity of (Na(+)-K+)-ATPase of NIDDM membranes, both in the absence and presence of digoxin were lower than the specific activity of normal enzymes (83.6 percent and 74.

Apparent and true metabolizable energy values of feedstuffs for ducks.

Two experiments were conducted, each with 24 White Pekin ducks, to determine the AME and TME content of five feedstuffs for ducks. In each experiment, fasting losses were obtained from six ducks and six ducks were used for each feedstuff. Each experiment lasted 102 h with an initial 48-h period and a 54-h excreta collection period.

Determination of metabolizable energy contents of feed ingredients for ducks.

The objective of the present experiments was to determine the AMEn and TMEn of various feed ingredients used in duck diets. In each of two experiments, 48 mature, male, White Pekin ducks were assigned in pairs to 24 cages based on initial weight. In each experiment, 12 ducks were assigned to each of three test ingredients and 12 ducks received dextrose for determination of endogenous losses of nitrogen and energy.