Energy and nutrient digestibility in NutriDense corn and other cereal grains fed to growing pigs

Two experiments were conducted to measure the energy and nutrient digestibilities in NutriDense corn and other cereal grains. An additional objective was to evaluate the effect of balancing diets with AA on the values measured for DE and ME of corn varieties. In Exp. 1, 6 growing pigs were fitted with a T-cannula in the distal ileum and allotted to a 6 x 6 Latin square design to measure apparent ileal digestibility (AID) and standardized ileal digestibility (SID) values for CP and AA in NutriDense corn, yellow dent corn, barley, wheat, and sorghum. Diets based on each of the 5 cereal grains were formulated, along with a N-free diet. Results of this experiment showed that the AID for most indispensable AA were greater (P < 0.05) in NutriDense corn and wheat than in the other cereal grains. The SID for Lys in NutriDense corn (77.6%) was greater (P < 0.05) than in yellow dent corn (68.5%), and sorghum (56.9%), but not different from wheat (75.1%) and barley (71.7%). The SID for Arg and Met in NutriDense corn also were greater (P < 0.05) than in yellow dent corn (88.1 and 87.2% vs. 84.5 and 82.8%, respectively). For the remaining indispensable AA, no differences in SID between NutriDense corn and yellow dent corn were observed. For all AA, the lowest values (P < 0.05) for AID and SID were obtained for sorghum. If calculated as grams of standardized ileal digestible AA per kilogram of DM, concentrations of all indispensable AA in NutriDense corn were greater (P < 0.05) than in yellow dent corn, but barley and wheat had greater concentrations of most AA than yellow dent corn and NutriDense corn. In Exp. 2, 12 growing barrows were placed in metabolism cages, and the DE and ME of NutriDense corn and yellow dent corn were measured. Both grains were used in diets without or with crystalline AA supplementation. Each diet was fed to 6 pigs in a 2-period, changeover design. The DE and the ME in NutriDense corn (4,004 and 3,922 kcal/kg of DM, respectively) were greater (P < 0.01) than in yellow dent corn (3,878 and 3,799 kcal/kg of DM, respectively). Values for DE and ME were not affected by the addition of crystalline AA to the diets. It is concluded that NutriDense corn has a greater value than yellow dent corn in diet formulations due to increased concentrations of digestible, indispensable AA and energy. However, barley and wheat have greater concentrations, whereas sorghum has lower concentrations, of many digestible AA than NutriDense corn.     

Platelet function in dogs: breed differences and effect of acetylsalicylic acid administration

BACKGROUND: Clinical studies investigating platelet function in dogs have had conflicting results that may be caused by normal physiologic variation in platelet response to agonists. OBJECTIVES: The objective of this study was to investigate platelet function in clinically healthy dogs of 4 different breeds by whole-blood aggregometry and with a point-of-care platelet function analyzer (PFA-100), and to evaluate the effect of acetylsalicylic acid (ASA) administration on the results from both methods. METHODS: Forty-five clinically healthy dogs (12 Cavalier King Charles Spaniels [CKCS], 12 Cairn Terriers, 10 Boxers, and 11 Labrador Retrievers) were included in the study. Platelet function was assessed by whole-blood aggregation with ADP (1, 5, 10, and 20 microM) as agonist and by PFA-100 using collagen and epinephrine (Col + Epi) and Col + ADP as agonists. Plasma thromboxane B(2) concentration was determined by an enzyme immunoassay. To investigate the effect of ASA, 10 dogs were dosed daily (75 or 250 mg ASA orally) for 4 consecutive days. RESULTS: A higher platelet aggregation response was found in CKCS compared to the other breeds. Longer PFA-100 closure time (Col + Epi) was found in Cairn Terriers compared to Boxers. Plasma thromboxane B(2) concentration was not statistically different between groups. Administration of ASA prolonged the PFA-100 closure times, using Col + Epi (but not Col + ADP) as agonists. Furthermore, ASA resulted in a decrease in whole-blood platelet aggregation. CONCLUSIONS: Platelet function is influenced by breed, depending upon the methodology applied. However, the importance of these breed differences remains to be investigated. The PFA-100 method with Col + Epi as agonists, and ADP-induced platelet aggregation appear to be sensitive to ASA in dogs.     

Microsensor analysis of oxygen and pH in the rice rhizosphere under field and laboratory conditions

 O₂ and pH microsensors were used to analyse the microdistribution of O₂ and pH inside and outside roots of lowland rice (Oryza sativa L.). The roots of 3-week-old transplants had O₂ concentrations of about 20% air saturation at the surface, but due to a high rate of O₂ consumption in the rhizosphere, the oxic region only extended about 0.4 mm into the surrounding soil. Also the fine lateral roots created an oxic zone extending about 0.15 mm into the soil. The O₂ concentration within the roots approached air saturation close to the base, but only about 40–60% of air saturation in a region about 8 cm below the base where lateral rootlets were present. A shift from air to N₂ around the leaves led to a drop of 50% in the O₂ concentration after 12 min at a distance of 8.5 cm from the base. Flowering plants did not export O₂ to the soil from the majority of their roots, but high microbial activity was present in a very thin biofilm covering the root surface. A brown colour around the thin lateral roots indicated some O₂ export from these also during flowering. No oxidized zone was present around the roots at later stages of crop growth. The roots caused only minor minima in pH (<0.2 pH units) in the rhizosphere as compared to the bulk soil. Illumination of the plants had no effect on rhizosphere pH. Received: 28 April 1998     

Experimental infections with Actinobacillus pleuropneumoniae in pigs--II. Comparison of antibiotics for oral strategic treatment.

The present study was aimed at scrutinizing the efficacy of oral antimicrobial treatments at experimental challenge using a strain of Actinobacillus pleuropneumoniae serotype 2 known to cause severe disease. SPF pigs aged 10 weeks were infected intranasally and the antimicrobial treatments were initiated 5 h prior to that exposure. Several antimicrobial drugs, as well as the length of the treatment period, were elucidated. The outcome of the challenge was monitored by registration of clinical symptoms, weight gains and the development of serum antibodies to A. pleuropneumoniae. At necropsy, the magnitude of pathological lesions in the respiratory tract and the rate of reisolation of the infective strain were recorded. Animals that became diseased displayed a decreased growth rate caused, to a large extent, by a reduced feed intake. The performance with respect to daily weight gain and feed conversion corresponded well with the clinical signs developed and serologic reactions, as well as with the findings made at necropsy. The results obtained among pigs treated with enrofloxacin, but also with florfenicol or chlortetracycline, were superior to those of pigs treated with penicillin, tiamulin or tilmicosin. A positive effect was obtained using a strategic in-feed medication against infection with A. pleuropneumoniae. Provided that the drug used is effective against the target microbe, initiating treatment prior to infection appeared to be more important than the length of the treatment. It should, however, be remembered that A. pleuropneumoniae was reisolated from all but one medicated group following an experimental challenge given after initiating the medication. Consequently medical treatment as described did not eradicate the microbe.     

The effect of cell density on biomass and fatty acid productivity during cultivation of Rhodomonas salina in a tubular photobioreactor

The microalga Rhodomonas salina is widely used in aquaculture. There is a need for optimization of the growth of the microalgae and its content of essential fatty acids. Here, the fatty acid profile of Rhodomonas in relation to cell density during cultivation in a tubular PBR is investigated. It is expected that cell density is an important factor in controlling productivity and fatty acid content of the microalgae because cell density is important in determining light availability due to the self‐shading of the algae. The carbon productivity as a function of cell density is described by a saturation curve. The carbon productivity and the productivity of total fatty acids are lowest at the lowest cell density, and independent of cell density at higher cell densities. The relative contribution of the two poly‐unsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) increases with increasing cell density and saturates at 1 × 10⁶ cells/ml. We conclude that large‐scale production of Rhodomonas in this tubular PBR should take place at cell densities of 1 × 10⁶ cells/ml, while there are indications for increasing difficulties in maintaining steady‐state production in this PBR at higher cell densities.     

Development of Nondestructive Screening Methods for Single Kernel Characterization of Wheat

The development of nondestructive screening methods for single seed protein, vitreousness, density, and hardness index has been studied for single kernels of European wheat. A single kernel procedure was applied involving, image analysis, near‐infrared transmittance (NIT) spectroscopy, laboratory density determination, single kernel characterization system (SKCS), and finally Kjeldahl protein determination on the crushed single kernels. Single kernel NIT spectroscopy showed excellent ability to determine protein content, and some ability for determination of single kernel vitreousness. Nondestructive determination of single kernel density, either based on NIT spectroscopy or based on image analysis and kernel weight, needs to be further improved for practical use. The use of SKCS hardness index as a true single kernel hardness reference in a NIT prediction model resulted in a poor predictability. However, by applying an averaging approach, in which single seed replicate measurements are mathematically simulated, a very good NIT prediction model was achieved. This suggests that the single seed NIT spectra contain hardness information, but that a single seed hardness method with higher accuracy is needed to achieve a good NIT prediction model for single kernel hardness.     

Effect of supplemented fungal phytase on performance and phosphorus availability by phosphorus-depleted juvenile rainbow trout (Oncorhynchus mykiss), and on the magnitude and composition of phosphorus waste output

The effect of a supplemental fungal phytase on performance and phosphorus availability by juvenile rainbow trout fed diets with a high inclusion of plant based protein and on the magnitude and composition of the waste phosphorus production was tested in a 2 × 3 factorial design at a temperature of 11 °C. Two factors comprised of two dietary fungal phytase levels (0 or 1400 U kg^? 1 feed^? 1), and three dietary total phosphorus levels (0.89, 0.97 or 1.12%). All fish were acclimated to the lowest total phosphorus diet for 16 days, which included 0.29% phytate-phosphorus and no supplemental fungal phytase, to ensure that they were depleted of phosphorus prior to the feeding trial.Growth and feed conversion ratios were not significantly affected by the increasing dietary phosphorus level or supplemental fungal phytase. Phosphorus availability increased significantly as a result of phytase supplementation, reaching an upper level of 74% at an available dietary phosphorus concentration of 0.71%. Adding fungal phytase to the diets improved the availability of phytate-phosphorus from an average of 6 to 64%. The fish retained 53–79% of the ingested phosphorus, while 24–44% was recovered in the faeces. The particulate phosphorus waste output was significantly higher in faeces from fish fed diets without fungal phytase compared to fish fed phytase supplemented diets. The dissolved/suspended phosphorus waste output represented 2–13% of the ingested phosphorus, and there was a significant increase in the dissolved/suspended phosphorus waste output from fish fed the phytase supplemented diet containing 0.71% available phosphorus, suggesting that the phosphorus requirement was reached at this phosphorus level. Consistent with this, there was a substantial increase in the dissolved/suspended phosphorus waste output from fish fed the phytase supplemented diet containing 0.81% available phosphorus, suggesting that the phosphorus requirement was exceeded in this group.This study demonstrated that phytase supplementation will be advantageous to the fish and the environment if supplemented to low-phosphorus diets containing a large share of plant-derived protein. Conversely, the results demonstrated that fungal phytase should not be supplemented to diets in which the available phosphorus level already meets the requirement of the fish, as this will lead to a significant increase in the dissolved/suspended phosphorus waste output.     

Can plot edge bias be reduced by means of airborne laser scanning?

This paper presents new methods for plot edge bias (PEB) correction of individual tree competition indices (CIs) using airborne laser scanning (ALS) as auxiliary information in multivariate ratio and multivariate regression models. I applied the methods to 557 plots from the Norwegian National Forest Inventory located in Hedmark County in South East Norway and compared them to the benchmarks methods linear expansion and simulated annealing by studying the individual tree growth predictions before and after PEB correction. Generally, the simulated annealing method seemed to improve growth prediction most and overall the existing methods performed better than those based on ALS. All PEB-correction methods tested gave minor changes in growth predictions and the absolute change in percent in adj. R² and Akaike's Information Criterion (AIC) was numerically small, with an average percentage change for the tested CIs between 1.8 for adj. R² and 0.6 for AIC of the observed values in the original data. The small differences in the results between the original data and the PEB-corrected data show that on average PEB remains a minor problem for individual tree growth prediction. Whether the results are valid for forests with significantly different spatial composition than that of this database remains to be confirmed.     

Effects of salinity on osmoregulation,growth and survival in Asian swamp eel (Monopterus albus) (Zuiew 1793)

The Asian swamp eel Monopterus albus is normally considered a freshwater species, but can also occasionally be found in brackish water. It is an obligate air‐breather with highly reduced gills, making its osmoregulation physiology interesting because the gills normally represent the primary site of osmoregulation in teleosts. Being a popular fish for human consumption, the swamp eel is cultured extensively in freshwater ponds in the Mekong Delta of Vietnam. However, very little is known about its salinity tolerance, which is becoming topical due to the increasing salt‐water intrusions into tropical deltas. We therefore studied how increased salinity affects survival, growth, blood pressure, heart rate, blood osmolality and plasma ions. All eels survived prolonged exposure to 5 and 10 g L^?1, although plasma osmolality increased significantly at 10 g L^?1. Further elevation to 15 and 20 g L^?1 was associated with significantly elevated mortality, with a corresponding increase in plasma osmolality and ion con‐centrations. Our results show that swamp eels thrive in 0–10 g L^?1 with an optimum growth between 0 and 9 g L^?1, indicating that utilization of low saline brackish waters for aquaculture is possible.     

Evaluation of Waxy Grain Sorghum for Ethanol Production

The objective of this research was to investigate the fermentation performance of waxy grain sorghum for ethanol production. Twenty‐five waxy grain sorghum varieties were evaluated with a laboratory dry‐grind procedure. Total starch and amylose contents were measured following colorimetric procedures. Total starch and amylose contents ranged from 65.4 to 76.3% and from 5.5 to 7.3%, respectively. Fermentation efficiencies were in the range of 86.0–92.2%, corresponding to ethanol yields of 2.61–3.03 gallons/bushel. The advantages of using waxy sorghums for ethanol production include easier gelatinization and low viscosity during liquefaction, higher starch and protein digestibility, higher free amino nitrogen (FAN) content, and shorter fermentation times. The results showed a strong linear relationship between FAN content and fermentation rate. Fermentation rate increased as FAN content increased, especially during the first 30 hr of fermentation (R² = 0.90). Total starch content in distillers dried grains with solubles (DDGS) was less than 1% for all waxy varieties.