Composition Of Basal Diet Research Articles

46 Efficacy of a biosynthetic 6-phytase depending on basal diet composition in weaning piglets

Abstract A study was conducted to evaluate the efficacy of biosynthetic 6-phytase depending on basal diet composition on growth performance and bone mineralization in weaned piglets. A total of 192 male weaned piglets with initial body weight (BW) of 8.47 ± 0.70 kg (at 33 d of age), distributed in a randomized block design with a 3 x 2 factorial arrangement of treatments. Three basal diet compositions (BD1: adequate in energy and nutrients with phytic P (PP) = 0.23%; BD2 = BD1 minus 70 kcal NE/kg, 0.15% points similarly in digestible P (dig.P) and calcium (Ca) with PP = 0.23%; and BD3 = BD1 minus 70 kcal NE/kg, 0.15% points similarly in dig.P and Ca with PP = 0.29%) and two phytase inclusion (Rovabio PhyPlus; 0 or 1,000 FTU/kg diet) were used in this experiment. The corn-soybean meal-based diets were fed into 2 phases: post-weaning 1 and 2 from 1 to 14 and 15 to 42 d, respectively. Body weight and feed intake were measured at the end of each phase, and average daily gain (ADG), average daily feed intake (ADFI) and feed to gain ratio (F:G) were calculated for the whole experimental period. At the end of the study, all piglets from 16 pens per treatment (n = 32 piglets/treatment) were euthanized and the metacarpi bones were collected for bone ash and P content determinations. There were significant interactions (P < 0.05) between basal diet composition and phytase inclusion on final BW, ADG, F:G, ash and P contents in metacarpal bones of piglets. Compared with unsupplemented diet, the addition of phytase in both nutrient-reduced diets improved final BW, ADG, F:G, ash and P contents in bones, while no improvements (P > 0.05) were observed on these parameters by phytase supplementation in adequate-nutrient diet. There was no significant interaction (P > 0.05) between basal diet composition and phytase inclusion on ADFI. Reduction in nutrients without (BD2) or with increasing dietary PP level (BD3) decreased (P = 0.004) ADFI, compared with adequate-nutrient diet. However, addition of biosynthetic 6-phytase improved (P = 0.03) ADFI by 5.3% compared with unsupplemented diets. The results of the present study highlight that adding biosynthetic 6-phytase to low energy and nutrient diets was more effective compared with the effects in an adequate-nutrient diet in weaned piglets.

Amino Acid Requirements for Nile Tilapia: An Update.

This review aims to consolidate the relevant published data exploring the amino acid (AA) requirements of Nile tilapia, Oreochromis niloticus, and to reach a new set of recommendations based on those data. There are still inconsistencies in lysine, sulfur-containing AA, threonine, tryptophan, branched-chain AA, and total aromatic AA recommendations in data that have appeared since 1988. This review finds that strain, size, basal diet composition, and assessment method may have contributed to the inconsistencies in AA recommendations. Currently, the expansion of precision AA nutrition diets for Nile tilapia is receiving more attention because of the demand for flexibility in widespread ingredient substitutions which will allow compliance with environmentally sustainable principles. Such approaches involve changes in diet ingredient composition with possible inclusions of non-bound essential and non-essential AAs. Increasing the inclusion of non-bound AAs into Nile tilapia diets may modify protein dynamics and influence AA requirements. Emerging evidence indicates that not only essential but also some non-essential amino acids regulate growth performance, fillet yield, and flesh quality, as well as reproductive performance, gut morphology, intestinal microbiota, and immune responses. Thus, this review considers current AA recommendations for Nile tilapia and proposes refinements that may better serve the needs of the tilapia industry.

Basal diet composition contributes to differential performance, intestinal health, and immunological responses to a microalgae-based feed ingredient in broiler chickens

Novel feed ingredients may improve poultry health, but functionality of these ingredients may vary across basal diet formulations. This study evaluated a proprietary algae ingredient's effects on broiler performance, intestinal health, systemic immunity, and metabolic/immune kinotypes between corn- or wheat-based diets. Ross 308 broilers were housed in 80 floor pens (14 birds/pen) and assigned to 1 of 4 corn or wheat-based diets ± 0.175% algae ingredient for 42 d. At the end of each 14 d starter, grower, and finisher period, 10 birds/treatment were euthanized for tissue collection to assess intestinal histomorphology, systemic immune cell populations by flow cytometry and kinotypes by peptide arrays. On d 28 and 29, forty-three birds/treatment underwent a 12 h feed restriction challenge followed by a fluorescein isothiocyanate-dextran intestinal permeability assay. For the entire 42 d study, wheat-based diets improved feed conversion rate (FCR) by 5 points compared to corn-based diets (P < 0.0001). Performance benefits related to algae inclusion were diet dependent, with algae inclusion improving 42 d FCR by 6 points only in corn-based diets (P=0.006). Birds fed wheat-based diets had reduced splenic monocyte/macrophage, CD1.1+, and T cell populations in the first 14 d (P < 0.0001) and reduced serum fluorescence on d 28/29 (P=0.0002). Algae inclusion in the corn-based diet increased villus height in the duodenum on d 28 and jejunum on d 42, while reducing splenic CD3+CD8α+ cytotoxic T cells 13.4 to 27.5% compared to the corn-based control at the same timepoints (P < 0.0001). Kinome results showed a significant innate immune toll-like receptor (TLR) response via MyD88 at d 14 in the small intestine of birds fed corn-based diets with algae that shifted to a more growth factor and adaptive immune-oriented response by d 42. Concurrent with immune changes, signaling changes indicative of lipid metabolism in the small intestine, ceca, and liver were seen in birds fed the corn-based diet with algae. The observed differential responses to basal diet composition and algae inclusion emphasize the need to comparatively evaluate feed ingredients in various diet formulations.

Role of choline in ruminant nutrition: a detailed review

Recent studies designate feed additives, such as rumen-protected choline (RPC), were seen decreasing the health disorders and upsurges the milk yield. Choline is an endogenous agent and the insufficiency of choline is very problematic. The deficiency has been documented in ruminants for a while. The scale of choline production is affected by administered dose, lactation stage, and basal diet composition. Endogenous synthesis through a pathway (PEMT) signifies a precarious source of choline. High occurrence of fatty liver disease happens in the dairy cows during lactation especially in the periparturient period and to lessen such incident high supply of choline is necessary. This supply is known to decrease the chances of hepatic fatty infiltration and upsurge the countenance of genes tangled in the transport of VLDL (very low-density lipoprotein). RPC typically provided as choline chloride is covered inside a shield of the fatty acid matrix. Therefore, to continue choline susceptibility on important mechanisms, like sparing of a methyl group (–CH3), supporting of animal metabolism, and remethylation of homocysteine via metabolite of betaine; choline must be provided in the rumen-protected form in the ration of dairy cows. Precisely concerning lactation, it is important to note that rumen-protected choline positively affects the performance of animals during the lactation period especially when supplementation started before calving and continues throughout the early lactation. But the difference of commercial products of rumen-protected choline in their rumen degradability and choline content is one of the big problems yet to be resolved.

Methane mitigation potential of 3-nitrooxypropanol in lactating cows is influenced by basal diet composition

The objective of this study was to investigate whether the CH4 mitigation potential of 3-nitrooxypropanol (3-NOP) in dairy cattle was affected by basal diet (BD) composition. The experiment involved 64 Holstein-Friesian dairy cows (146 ± 45 d in milk at the start of trial; mean ± SD) in 2 overlapping crossover trials, each consisting of 2 measurement periods. Cows were blocked according to parity, d in milk, and milk yield, and randomly allocated to 1 of 3 diets: a grass silage-based diet (GS) consisting of 30% concentrates and 70% grass silage (DM basis), a grass silage- and corn silage-mixed diet (GSCS) consisting of 30% concentrates, 42% grass silage, and 28% corn silage (DM basis), or a corn silage-based diet (CS) consisting of 30% concentrates, 14% grass silage, and 56% corn silage (DM basis). Two types of concentrates were formulated, viz. a concentrate for the GS diet and a concentrate for the CS diet, to meet the energy and protein requirements for maintenance and milk production. The concentrate for the GSCS diet consisted of a 50:50 mixture of both concentrates. Subsequently, the cows within each type of BD received 2 treatments in a crossover design: either 60 mg of 3-NOP/kg of DM (NOP60) and a placebo with 0 mg of 3-NOP/kg of DM (NOP0) in one crossover or 80 mg of 3-NOP/kg of DM (NOP80) and NOP0 in the other crossover. Diets were provided as total mixed ration in feed bins, which automatically recorded feed intake. Additional concentrate was fed in the GreenFeed system that was used to measure emissions of CH4 and H2. The CS diets resulted in a reduced CH4 yield (g/kg DMI) and CH4 intensity (g/kg milk). Feeding 3-NOP resulted in a decreased DMI. Milk production and composition did not differ between NOP60 and NOP0, whereas milk yield and the yield of major components decreased for NOP80 compared with NOP0. Feed efficiency was not affected by feeding 3-NOP. Interactions between BD and supplementation of 3-NOP were observed for the production (g/d) and yield (g/kg DMI) of both CH4 and H2, indicating that the mitigating effect of 3-NOP depended on the composition of the BD. Emissions of CH4 decreased upon 3-NOP supplementation for all BD, but the decrease in CH4 emissions was smaller for GS (-26.2% for NOP60 and -28.4% for NOP80 in CH4 yield) compared with both GSCS (-35.1% for NOP60 and -37.9% for NOP80 for CH4 yield) and CS (-34.8% for NOP60 and -41.6% for NOP80 for CH4 yield), with no difference between the latter 2 BD. Emissions of H2 increased upon 3-NOP supplementation for all BD, but the H2 yield (g/kg DMI) increased 3.16 and 3.30-fold, respectively, when NOP60 and NOP80 were supplemented to GS, and 4.70 and 4.96 fold, respectively, when NOP60 and NOP80 were supplemented to CS. In conclusion, 3-NOP can effectively decrease CH4 emissions in dairy cows across diets, but the level of CH4 mitigation is greater when supplemented in a corn silage-based diet compared with a grass silage-based diet.

Haematology, Carcass and Fatty Acid Composition of Finishing Broilers Fed Enzyme Supplemented Expeller Copra Meal in Corn-Animal Protein Diets

ABSTRACT This study analyzes the effect of different levels of expeller copra meal (ECM) in animal protein-based diets with enzyme on the haematology, carcass and fatty acid composition of broilers. One hundred and sixty 20 days old Cobb broilers were assigned 8 different diets, 2 of them being controls and 6 others containing ECM at 150, 300 and 450 g/kg, with or without enzymes. Four replicate cages of 5 birds each were fed the diets in a completely randomized design. Higher white blood cell (WBC) counts were obtained in chickens fed the control and 150 g/kg ECM with enzyme (p 0.05). In conclusion, inclusion of ECM up to 300 g/kg in corn-animal protein diets has no adverse effects on most broiler haematological variables, but meat fatty acid composition may be altered. More research into basal diet composition, enzyme source and concentration is recommended.

Enzyme Supplementation of Commercial Feed Diluted with Copra Meal for Growing Pullets

Two hundred 42 days old Shaver Star-cross pullets were subjected to five dietary treatments comprising of a commercial pullet feed alone and commercial pullet feed diluted with two levels of copra meal (CM) at two levels ( 200 and 300g/kg) with or without Challenzyme. Data were collected on growth performance (feed intake, weight gain and feed conversion ratio) for a period of 84 days (42-126 days). Results showed no significant difference between supplemented and control groups in growth performance across the dietary treatments at (P > 0.05). Cost of the kg feed was linearly reduced on the dilution diets but feed cost per unit live weight gain was not different among the treatments (P > 0.05). In conclusion, diluting commercial feed with CM up to 300g/kg does not compromise pullet performance during the growing period. These findings will reduce cost of pullet rearing and add value to copra meal in coconut producing regions. There is need for more research into higher rates of dilution, composition of basal diet, enzyme source and inclusion level.

Studies on the measurement of ileal calcium digestibility of calcium sources in broiler chickens

Results from 3 experiments relating to the measurement of ileal calcium (Ca) digestibility in 4 different Ca sources for broiler chickens are presented herein. The first experiment was conducted to determine the effect of basal diet composition on the true Ca digestibility of limestone, meat and bone meal (MBM), monocalcium phosphate (MCP), and dicalcium phosphate (DCP). Eight experimental diets were developed based on 2 basal diets (corn-based or corn starch-based) with each of the 4 Ca sources. Two Ca-free diets representing both basal diets were used to determine the endogenous Ca losses. Each diet was randomly allotted to 6 replicate cages (6 birds per cage) and fed from 21 to 24 D post-hatch. Calcium digestibility of corn-based diet was higher (P < 0.05) than the corn starch-based purified diet. The average true Ca digestibility coefficients of limestone, MBM, MCP, and DCP were determined to be 0.51, 0.41, 0.43, and 0.32, respectively. The second experiment was conducted to examine the effect of indicator type on the apparent Ca digestibility of limestone. Two experimental diets with either titanium dioxide or acid insoluble ash (Celite) were developed. Each diet was randomly allotted to 6 replicate cages (8 birds per cage) and fed from 21 to 24 D post-hatch. Total tract Ca retention was also measured using the indicator ratios. Indicator type had no influence (P > 0.05) on the digestibility measurements. Ca retention determined using acid insoluble ash was higher (P < 0.05) compared to that determined using titanium dioxide. The third experiment was conducted to determine the effect of dietary adaptation length on apparent Ca digestibility of limestone. The experimental diet was offered from day 21 to 6 replicates (6 birds per cage) each for 24, 72, 120, or 168h and the ileal digesta were collected. Calcium digestibility at 24h was higher (P < 0.05), and increasing the adaptation length from 72 to 120h had no effect (P > 0.05) on the digestibility.

Effects of feeding extruded linseed on production performance and milk fatty acid profile in dairy cows: A meta-analysis

The objectives of this study were to quantify the effects on production performance and milk fatty acid (FA) profile of feeding dairy cows extruded linseed (EL), a feed rich in α-linolenic acid, and to assess the variability of the responses related to the dose of EL and the basal diet composition. This meta-analysis was carried out using only data from trials including a control diet without fat supplementation. The dependent variables were defined by the mean differences between values from EL-supplemented groups and values from control groups. The data were processed by regression testing the dose effect, multivariable regression testing the effect of each potential interfering factor associated with the dose effect, and then stepwise regression with backward elimination procedure with all potential interfering factors retained in previous steps. This entire strategy was also applied to a restricted data set, including only trials conducted inside a practical range of fat feeding (only supplemented diets with <60 g of fat/kg of dry matter and supplemented with <600 g of fat from EL). The whole data set consisted of 17 publications, representing 21 control diets and 29 EL-supplemented diets. The daily intake of fat from EL supplementation ranged from 87 to 1,194 g/cow per day. The dry matter intake was numerically reduced in high-fat diets. Extruded linseed supplementation increased milk yield (0.72 kg/d in the restricted data set) and decreased milk protein content by a dilutive effect (-0.58 g/kg in the restricted data set). No effect of dose or diet was identified on dry matter intake, milk yield, or milk protein content. Milk fat content decreased when EL was supplemented to diets with high proportion of corn silage in the forage (-2.8 g/kg between low and high corn silage-based diets in the restricted data set) but did not decrease when the diet contained alfalfa hay. Milk trans-10 18:1 proportion increased when EL was supplemented to high corn silage-based diets. A shift in ruminal biohydrogenation pathways, from trans-11 18:1 to trans-10 18:1, probably occurred when supplementing EL with high corn silage-based diets related to a change in the activity or composition of the microbial equilibrium in the rumen. The sum of pairs 4:0 to 14:0 (FA synthesized de novo by the udder), palmitic acid, and the sum of saturated FA decreased linearly, whereas oleic acid, vaccenic acid, rumenic acid, α-linolenic acid, and the sums of mono- and polyunsaturated FA increased linearly when the daily intake of fat from EL was increased. In experimental conditions, EL supplementation increased linearly proportions of potentially human health-beneficial FA in milk (i.e., oleic acid, vaccenic acid, rumenic acid, α-linolenic acid, total polyunsaturated FA), but should be used cautiously in corn silage-based diets.

Prenatal exposure to soy and selenium reduces prostate cancer risk factors in TRAMP mice more than exposure beginning at six weeks.

Diets high in soy and selenium (Se) decrease prostate cancer risk factors in healthy rats. The purpose of this study was to determine whether treatment with high levels of soy and/or supplemental Se would decrease prostate cancer risk factors in the Transgenic Adenocarcinoma of Mouse Prostate (TRAMP) mouse, and whether timing of the introduction of these nutrients would affect risk reduction. Male hemizygous [C57BL/6 × FVB]F1 TRAMP mice were exposed to stock diets high or devoid of soy, with or without a supplement of Se-methylselenocysteine (MSC) starting at conception (10 mg Se/L in drinking water of pregnant/nursing dams; daily bolus of 4 mg Se/kg body weight to pups after weaning) or at 6 weeks of age in a 2 × 2 factorial design. Mice were killed at 12 weeks (n per dietary treatment = 20-30). Liver and serum Se concentrations were increased by MSC supplementation (P < 0.001), high-soy diet (P < 0.05), and initiation of dietary treatments at conception (P < 0.05). MSC supplementation had greater effects in mice fed the zero-soy basal diet, compared to the high-soy formulation (Pinteraction < 0.01). These same three interventions, individually and interactively, decreased body weight and epididymal fat pad weights, and steady state levels of mRNA for Cyp19a1 (aromatase) and Srd5a1 (5α-reductase). In contrast, MSC was the only treatment that decreased urogenital tract weights (P < 0.001), serum IGF-1 levels (P < 0.002), and Gleason scores (P < 0.05). Supplemental MSC reduces risk of prostate cancer in TRAMP mice. Basal diet composition (zero- vs. high-soy) can modify MSC's chemopreventive effects. Initiation of dietary treatments from conception maximizes chemopreventive effects of MSC. Prenatal Se status may have long-lasting effects on development and progression of prostate cancer.

Effects of Coriander (Coriandrum sativumL.) Seed Powder on Growth Performance of Broiler Chickens

This study was conducted to investigate the effects of different levels of coriander (Coriandrum sativum) seed powder on growth performance of broiler chickens. A total of 90 day-old broiler chicks procured from Central Poultry Development Organization Chandigarh were allocated randomly into three treatments group. Control group (T1): basal diet. Test group (T2): basal diet + 1.5 g coriander seed powder/kgdiet and test group (T3): basal diet + 2.5 g coriander seed powder/kg diet. The ingredient composition of basal diet was maize (46%), groundnut cake (30%), rice polish (10%), fish meal (13%) and mineral mixture (1%) fortified with vitamin A, D, E, K and water soluble vitamins. Result showed that the inclusion of coriander seed powder in broiler ration (T3 group) significantly increased overall body weight and weight gain and feed consumption as compared to other groups. These results suggest that coriander powder in the diet could replace synthetic antibiotics and could be regarded as natural feed additives and growth promoters in poultry diets.

Reductions in milk Δ9-desaturation ratios to oral dosing of cobalt-acetate are accompanied by the downregulation of SCD1 in lactating ewes

Oral administration of cobalt has been proven to alter milk fatty acid (FA) composition consistent with an inhibition of mammary stearoyl-coenzyme A desaturase (SCD) activity in ruminants, but the mechanisms explaining its mode of action remain uncertain. In this study, Co (as Co-acetate) was dosed to lactating ewes with the aims of examining mammary gene expression during Co-induced changes in milk FA composition, and estimating the endogenous synthesis of SCD products in milk of sheep fed an 18:3n-3-enriched diet. Twelve Assaf ewes fed a diet supplemented with 2% linseed oil were allocated to 2 experimental groups and received an oral drench supplying either 0 (control) or 9mg of Co/kg of body weight per day. Treatments were administered in 3 equal doses at 8-h intervals for 6 d. No effects of Co administration on animal performance were observed. The changes in milk FA (namely, reductions in most cis-9-containing FA) were consistent with an inhibition of SCD in the absence of detectable effects on the relative importance of mammary de novo synthesis and FA uptake. The high proportion of endogenous cis-9 trans-11 18:2 observed in this study (89%) would agree with a greater supply of trans-11 18:1 of ruminal origin in ewes fed linseed oil, compared with previous estimates in sheep fed a diet without lipid supplementation. Differences between studies could also be related to diet-induced changes in SCD activity. Altogether, both mechanisms would support that basal diet composition is a major determinant of the relative contribution of Δ9-desaturation to milk FA profile. Similarly, the consumption of a diet rich in 18:3n-3might also explain the low proportion of milk cis-9 18:1 estimated to derive from Δ9-desaturation (29%). The administration of Co to ewes fed linseed oil allowed to discriminate minor 18:3 isomers in milk, such as cis-9 trans-12 cis-15 18:3, as SCD products. Finally, Co dosing lowered the mRNA abundance of SCD1 in the mammary secretory tissue (33%), whereas no changes were detected in the SCD5 isoform or in the studied transcription factors (SREBF1, PPARG, SP1, and EGR2). These results suggest that the mode of action of Co in dairy ewes would be at least partly mediated by the downregulation of SCD1.

Soy Content of Basal Diets Determines the Effects of Supplemental Selenium in Male Mice

The effects of supplemental Se in rodent models may depend upon composition of the basal diet to which it is added. Wild-type male littermates of Transgenic Adenocarcinoma of Mouse Prostate mice were fed until 18 wk of age 1 of 2 Se-adequate stock diets high in soy (HS) or low in phytoestrogens (LP) or the same diets supplemented with 3.0 mg Se/kg diet as seleno-methylselenocysteine. Body and abdominal fat pad weights were lower (P < 0.01) in mice fed the HS diet. Supplemental Se reduced fat pad weights in mice receiving the LP diet but increased body and fat pad weights in mice consuming the HS formulation (P-interaction < 0.005). Serum free triiodothyronine concentrations were unaffected by supplemental Se in mice fed the LP diet but were decreased by Se supplementation of mice given the HS feed (P-interaction < 0.02). Free thyroxine concentrations were higher in mice consuming the HS diet regardless of Se intake (P < 0.001). Hepatic mRNA for iodothyronine deiodinase I was lower (P < 0.001) in mice fed the HS diet. Supplementation of Se increased this mRNA (P < 0.001) in both diet groups. Results from this study show a significant interaction between the composition of basal diets and the effects of supplemental Se with respect to body composition. These findings have important implications for future studies in rodent models of the effects of supplemental Se on heart disease, cancer, diabetes, and other conditions related to body weight and composition.

Effects of Supplementation of Dietary Bamboo Charcoal on Growth Performance and Body Composition of Juvenile Japanese Flounder, Paralichthys olivaceus

A 50‐d feeding trial was conducted to determine the effect of dietary bamboo charcoal (BC) on growth performance, body composition, and ammonia nitrogen excretion of juvenile Japanese flounder, Paralichthys olivaceus. Six levels of BC (0, 0.25, 0.5, 1, 2, and 4%) were supplemented to the basal diet composition and fed to fish (initial body weight [BW], 3 ± 0.1 g). At the end of the trial, fish were used for the determination of apparent digestibility of dry matter and protein, and cumulative ammonia nitrogen excretion rates. Weight gain, specific growth rate, feed efficiency ratio, and protein efficiency ratios of fish fed 0.5% BC diet were significantly (P &lt; 0.05) higher than those of fish fed the control diet (without BC). Moreover, apparent digestibility of dry matter and protein of fish fed BC diets were significantly (P &lt; 0.05) higher than those of fish fed the control diet. Cumulative ammonia nitrogen excretion over a subsequent 12‐h period decreased with increasing dietary BC. In conclusion, the diet supplemented with 0.5% BC was found to have a suitable level to fulfill the maximum growth performance and to decrease the ammonia nitrogen excretion of flounder, under the conditions applied in this study.

Basal diet composition determines effects of supplemental selenium

The effects of supplemental selenium (Se) in animal models of prostate cancer and diabetes may depend upon the composition of the basal diet to which Se is added. In this study, we examined effects of dietary Se and isoflavones, alone and in combination, on body weight, fat mass, and serum T3 levels. Non‐transgenic male littermates of TRAMP mice, produced for a study of tumorigenesis, were weaned to one of two Se‐adequate stock diets, either low (Zeigler Bros. Phytoestrogen‐Red. Diet I) or high (Harlan Teklad 8604) in isoflavones, or the same diets supplemented with 3.0 ppm Se as Se‐methylselenocysteine. Mice were killed at 18 weeks of age. Serum levels of T3 were measured using ELISA kits. Hepatic expression of the iodothyronine deiodinase I gene was determined by real time RT‐PCR. Values in a column not sharing a common subscript are significantly different (p &lt; 0.05). These data show a significant interaction between isoflavones and Se, and demonstrate opposite effects of supplemental Se based on the isoflavone content of the basal diet. (Supported by NIH CA122235 to MJC). Final Body Wt (g) Abdom. Fat (g/35 g BW) T3 (pg/ml serum) Relative DIO1 Exprsn. Se − Iso 38.1 ± 4.9a 2.78 ± 0.29a 0.70 ± 0.13cd 1.0 ± 0.12b +Se − Iso 35.2 ± 4.2ab 1.75 ± 0.51bc 0.93 ± 0.11bc 1.49 ± 0.12a Se +Iso 31.4 ± 2.5b 1.23 ± 0.13c 1.99 ± 0.37a 1.47 ± 0.23a +Se +Iso 35.5 ± 2.8a 1.90 ± 0.17b 1.31 ± 0.19b 1.11 ± 0.14b

Prevention of insulin resistance by n-3 polyunsaturated fatty acids

Review results from recent human and animal studies regarding the effects of n-3 polyunsaturated fatty acid (PUFA) in the prevention of insulin resistance. Overall, results from animal studies indicate that fish oil and individual n-3 PUFA [alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)] prevented insulin resistance in animal models; results from two studies in mice showed that EPA increased insulin secretion. ALA, EPA, and DHA may act at different sites and involve different mechanisms. Fish oil or purified EPA reduced insulin resistance in some but not other human studies in normal weight and obese individuals. Discrepancies may be due to differences in health status of participants, macronutrient, fatty acid, and antioxidant nutrient composition of basal diet; amount, duration, and fatty acid composition of n-3 PUFA, and methods used to assess insulin resistance. Moderate amounts of n-3 PUFA did not improve or deteriorate glucose control in type 2 diabetics. n-3 PUFA supplementation has clinical significance in the prevention and reversal of insulin resistance. However, increased intake of n-3 PUFA should be part of an overall healthy lifestyle that includes weight control, exercise, and reduction in the intake of refined sugars, n-6, saturated, and trans fatty acids.

Effect of blueberry feeding on plasma lipids in pigs

Two feeding trials were conducted with pigs to determine the effects of blueberry supplementation on plasma lipid levels and other indices of cardiovascular benefit. In the first trial, where basal diets contained a high level of plant-based components (70 % soya, oats and barley), supplementation with 1, 2 and 4 % blueberries resulted in a decrease in total, LDL- and HDL-cholesterol. The greatest reduction was observed in the 2 % blueberry-fed pigs, where total, LDL- and HDL-cholesterol were reduced 11.7, 15.1 and 8.3 %, respectively. In the second trial where basal diets contained only 20 % (w/w) of soya, oats and barley, the lipid-modulating effect of blueberries was attenuated, so that supplementation with 1.5 % blueberries reduced total cholesterol by 8 %, which occurred only in pigs whose diets had been supplemented with cholesterol (0.08 %), NaCl (0.11 %) and fructose (9 %). In the first feeding trial, blueberry supplementation had no effect on blood platelet activity. Blueberry supplementation also had no effect on the susceptibility of leucocyte DNA to oxidation in the first trial and no effect on the susceptibility of LDL to oxidation in the second trial. Results of these two feeding trials are discussed in relation to the effects of basal diet composition on lipid-modulating effects of blueberries.

Hydrolytic Activity toward Pyridoxine-5′-β-d-Glucoside in Rat Intestinal Mucosa Is Not Increased by Vitamin B-6 Deficiency: Effect of Basal Diet Composition and Pyridoxine Intake

Pyridoxine-5'-beta-D-glucoside (PNG), a glycosylated form of dietary vitamin B-6, is partially hydrolyzed in the small intestine by the cytosolic enzyme pyridoxine-5'-beta-D-glucoside hydrolase (PNG hydrolase) and by the brush border enzyme lactase phlorizin hydrolase (LPH) to release free pyridoxine (PN). This laboratory has previously shown that PNG hydrolase activity is inversely related to dietary vitamin B-6 in rats and guinea pigs. The current investigation was done to examine the effect of dietary PN on PNG hydrolytic activity and its distribution. Nutrient compositional differences between the AIN-76A and AIN-93G purified diets that were unrelated to vitamin B-6 were also examined in relation to PNG hydrolysis in rat small intestinal mucosa. Study one included rats (n = 29) that were fed the AIN-93G diet providing a range of PN concentrations for 5 wk. Rats (n = 49) in study two were fed either AIN-76A or AIN-93G each with graded concentrations of PN. In both studies, rat growth and plasma and liver pyridoxal 5'-phosphate (PLP) concentrations increased (P < 0.05) with increasing concentrations of dietary PN. PNG hydrolytic activity localized to the brush border membrane was five times that measured in the cytosol. Cytosolic PNG hydrolytic activity increased significantly with increasing dietary PN concentration in rats fed the AIN-76A, but not AIN-93G diet. Activity in the mucosal total membrane fraction did not increase in proportion to dietary PN concentration for either diet. Regardless of dietary PN concentration, the basal nutrient composition of the diets affected growth and PNG hydrolytic activity in intestinal mucosa. In contrast to previous results from this laboratory, intestinal hydrolytic activity toward PNG did not increase in vitamin B-6-deficient rats.

Effects of Dietary Pigeon Pea (Cajanus cajan L.) Seed Meal on Growth Performance in Piglets and Growing Pigs

To investigate the effects of dietary pigeon pea (Cajanus cajan L.) seed meal (PM) on growth performance in early life stage of pigs and whether the raw PM could be used as a plant protein resource, 32 piglets were randomly allotted into 0, 10, 20 and 30% dietary PM groups of 8 pigs (2 pigs per pen×4 replicates) at 15kg. All pigs were given ad libitum access to water and feed until they attained to the final 30kg body weight. Then, the composition of basal diet was changed from piglet diet to growing pig (30-60kg) diet. In both experimental feeding periods, feed intake, body weight gain, feeding period (day) until respective final body weights and feed conversion ratio were measured. Up to 20% PM group in growing pigs, there was no definite difference in the feed intake between each group, but the body weight gain tended to insignificantly decrease with the increasing dietary PM level, resulting in the insignificant increase of the feeding period and feed conversion ratio. However, all parameters significantly changed (P<0.05) at 30% PM level in growing pigs except in the feed conversion ratio which showed a significant difference (P<0.05) between 10 and 30% PM levels.This suggests that as a plant protein source the PM could be incorporated beyond the 30% level for piglet diet (53.4% substitution rate of PM for soybean meal) and up to the 20% level for growing pig diet (76% substitution rate of PM for soybean meal) and that the effective utilization of PM enables to reduce the feed cost in pig production.

Effect of Ratio of Unsaturated to Saturated Fatty Acids of the Dietary Lipid Fraction on Utilization and Metabolizable Energy of Added Fats in Young Chicks

Relationships between the ratio of unsaturated to saturated fatty acids (U:S) in the diet and the utilization and AMEn of added fat were studied using the results of a number of previously reported experiments. Mathematical equations relating fat AMEn, fat utilization, and palmitic, oleic, and linoleic acid utilization to the U:S were calculated for young broiler chicks. Best fit regression equations for added fat utilization and fat AMEn were exponential, showing fat utilization increased very steeply in the U:S range of 0 to 2.5, reaching a near asymptotical maximum at a U:S of 4 or more. Synergism between added fats, due to blending vegetable oils with animal fats or using basal diets with unsaturated lipid fractions, led to increased animal fat utilization values. The utilization of saturated fatty acids was especially affected by synergism, whereas utilization of unsaturated fatty acids was not influenced by changing U:S. The origin of effects of factors influencing fat utilization, such as level of fat inclusion and basal diet composition, appeared to be through variation in degree of saturation of the total dietary lipid fraction. For young broilers, about 75% of the variation in fat utilization and AMEn, was due to differences in the chemical composition of the fat fraction.