Efficacy of different commercial phytase enzymes and development of an available phosphorus release curve for Escherichia coli-derived phytases in nursery pigs

Posted in: Environment, Production by admin on August 5, 2011 | No Comments

In 2 experiments, a total of 184 pigs (PIC, initial BW of 10.3 and 9.7 kg for Exp. 1 and 2, respectively) were used to develop an available P (aP) release curve for commercially available Escherichia coli- derived phytases. In both experiments, pigs were fed a corn-soybean meal basal diet (0.06% aP) and 2 diets with added inorganic P (iP) from monocalcium phosphate (Exp. 1: 0.075 and 0.15% aP; Exp. 2: 0.07 and 0.14% aP) to develop a standard curve. In Exp. 1, 100, 175, 250, or 500 phytase units (FTU)/kg of OptiPhos 2000 or 200, 350, 500, or 1,000 FTU/kg of Phyzyme XP were added to the basal diet. In Exp. 2, 250, 500, 750, or 1,000 FTU/kg of OptiPhos 2000; 500, 1,000, or 1,500 FTU/kg of Phyzyme XP; or 1,850 or 3,700 FTU/ kg of Ronozyme P were added to the basal diet. One FTU was defined as the amount of enzyme required to release 1 μmol of iP per minute from sodium phytate at 37°C. For all phytase products, the manufacturer-guaranteed phytase activities were used in diet formulation. All diets were analyzed for phytase activity using both the Phytex and AOAC methods. Pigs were blocked by sex and BW and allotted to individual pens with 8 pens per treatment. Pigs were killed on d 21, and fibulas were collected and analyzed for bone ash. In both experiments, increasing iP improved G:F and percentage bone ash. Pigs fed increasing OptiPhos had improved percentage bone ash, as did pigs fed increasing Phyzyme XP. In Exp. 2, increasing Ronozyme P improved percentage bone ash. Using analyzed values from the AOAC method and percentage bone ash as the response variable, an aP release curve was developed for up to 1,000 FTU/kg of E. coli-derived phytases (OptiPhos 2000 and Phyzyme XP) in P-deficient diets. The prediction equation was Y = –0.000000125X2 + 0.000236X + 0.016, where Y = aP release (%) and X = analyzed phytase (FTU/kg) in the diet.

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Conjugated linoleic acid differentially regulates fat deposition in backfat and longissimus muscle of finishing pigs

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This experiment was conducted to investigate the effects of extracellular CLA on proliferation and differentiation of cultured adipocytes and its dietary supplementation on backfat and intramuscular fat deposition in finishing pigs. Seven-day-old Duroc × Landrace × Large White pigs were killed to obtain adipocytes for culture. Adding 3 forms of CLA (cis-9, trans-11 CLA, trans-10, cis-12 CLA, or CLA mixture) at concentrations of 50, 100, 150, 200, 250, 300, 350, and 400 μM to culture medium for 10 d increased cell differentiation. In addition, 3 forms of CLA enhanced cell proliferation at 50 to 350 μM and inhibited cell proliferation at a concentration of 400 μM. Seventy-two Duroc × Landrace × Large White crossbred gilts weighing 60.7 kg were randomly assigned to 1 of the 3 dietary treatments (control, 1.25% CLA, and 2.5% CLA). The pigs were slaughtered at 100.0kg. Dietary CLA increased lean percentage (3.5 to 4.7%), intramuscular fat content, and shear force, but reduced 10th- and first-rib backfat depth and lipid oxidation. The adipocyte diameter in backfat or LM was not affected by CLA. Supplemented CLA reduced Δ9-desaturase activity in backfat and LM, as well as fatty acid synthetase activity and lipoprotein lipase activity in backfat, but enhanced adipocyte fatty acid binding protein mRNA content in LM. These data indicate that dietary CLA regulates fat deposition by affecting adipocyte proliferation, adipocyte differentiation, gene expression, and key metabolic enzymes of lipid metabolism.

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The effect of diet composition on tryptophan requirement of young piglets

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 The aim of the study was to evaluate the requirement for Trp in relation to diet composition in piglets in the period after weaning (BW range of 9 to 24 kg). Two Trp-deficient [relative to the Dutch (CVB, 1996) and NRC (NRC, 1998) requirement values for piglets of 10 to 20 kg of BW] basal diets were formulated: one based on corn and soybean meal and a second one based on wheat, barley, soybean meal, peas, and whey powder [10.0 g/kg of apparent ileal digestible (AID) Lys; 1.4 g/kg of AID Trp; 1.5 g/kg of standardized ileal digestible (SID) Trp]. Both basal diets were supplemented with 0.3, 0.6, and 0.9 g of l-Trp per kg of diet to obtain diets with 1.7, 2.0, and 2.3 g of AID Trp per kg (1.8, 2.1, and 2.4 g of SID Trp per kg), respectively. Each of the 8 treatments was evaluated in 8 replicates (pens with 8 male or female piglets). Average daily feed intake, ADG, and G:F were measured as response criteria. Over the 28-d experimental period, ADG and G:F were greater for the treatments on the wheat/barley diet compared with those on the corn/ soybean meal and were increased by the level of Trp in the diet. Average daily feed intake was only increased by the level of Trp supplementation. Increasing the Trp level increased ADFI for the corn/soybean meal diet up to 2.3 g of AID Trp per kg (2.4 g of SID Trp per kg) and up to 2.0 g of AID Trp per kg (2.1 g of SID Trp per kg) in the wheat/barley diet. For both diet types supplementation of free l-Trp increased the G:F up to 1.7 g of AID Trp per kg (1.8 g of SID Trp per kg). Nonlinear regression analysis of the response curves for ADFI using an exponential model for estimating a requirement value for Trp (defined as the Trp level resulting in 95% of the maximum response) revealed a requirement estimate of 2.3 g of AID Trp per kg for the corn/soybean mealbased diet and 2.1 g of AID Trp per kg for the wheat/ barley-based diet, equivalent to 2.4 and 2.2 g of SID Trp per kg of diet, respectively. For ADG, a requirement estimate of 2.1 g of AID Trp per kg for both types of diets was derived, equivalent to 2.2 g of SID Trp per kg of diet. The Trp requirement for young piglets seems to be greater than indicated by some commonly used recommendations and does not seem largely dependent on diet ingredient composition.

Amino acid digestibility and energy concentration of high-protein corn dried distillers grains and high-protein sorghum dried distillers grains with solubles for swine

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A study was conducted to determine the AA digestibility and energy concentration of a specialized high-protein corn distillers dried grains (HPCDDG) product and a high-protein sorghum dried distillers grains with solubles (HPS-DDGS) product. Six growing barrows (BW = 22.7 kg) were surgically fitted with T-cannulas at the terminal ileum and allotted randomly to 3 treatments in a crossover design with 3 periods. The treatment diets were 1) 67% HPC-DDG and 2) 50% HPS-DDGS as the sole protein sources, and 3) an N-free diet for determining basal endogenous AA loss. All diets contained 0.25% chromic oxide as an inert marker. Digesta and fecal samples were collected and analyzed for AA and energy concentrations. After chemical analysis, standardized and apparent ileal digestible (SID and AID, respectively) AA and GE were determined for each coproduct. The DE, ME, and NE values for HPC-DDG and HPS-DDGS also were calculated. The chemical composition of HPC-DDG and HPS-DDGS on a DM basis was 40.8% CP, 5.4% fat, 22.9% ADF, 36.6% NDF, 0.04% Ca, and 0.42% P and 48.2% CP, 3.1% fat, 17.5% ADF, 20.4% NDF, 0.13% Ca, and 0.82% P, respectively. The DM content of HPC-DDG and HPS-DDGS was 89.50 and 91.88%, respectively. Analyzed AA content of HPC-DDG was greater than that of traditional corn DDGS. The Lys content of HPC-DDG was 1.36% (DM basis), resulting in a Lys-to-CP ratio of 3.2%. In HPS-DDGS, most AA were present in greater proportions than in HPC-DDG or conventional sorghum DDGS. The HPS-DDGS Lys content was 1.7% (DM basis), equivalent to a Lys-to- CP ratio of 3.5%. In HPC-DDG, the AID for Lys, Met, Thr, and Trp were 65.9, 87.0, 72.8, and 76.2%, respectively, and SID values were 67.8, 87.5, 75.0, and 78.6%, respectively. For HPS-DDGS, the AID for Lys, Met, Thr, and Trp were 51.9, 73.0, 60.6, and 71.7%, respectively, and SID values were 53.7, 73.8, 63.0, and 73.8%, respectively. The GE, DE, and calculated ME and NE values were 5,293, 3,703, 3,426, and 2,131kcal/ kg of DM, respectively, for HPC-DDG and 5,108, 3,878, 3,549, and 2,256 kcal/kg of DM, respectively, for HPSDDGS. Results indicate that both coproducts are well suited for use in swine diets and that actual AA digestibility values and calculated energy concentrations can now be used in swine diet formulation.

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An application of change-point recursive models to the relationship between litter size and number of stillborns in pigs

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We developed and implemented change-point recursive models and compared them with a linear recursive model and a standard mixed model (SMM), in the scope of the relationship between litter size (LS) and number of stillborns (NSB) in pigs. The proposed approach allows us to estimate the point of change in multiple-segment modeling of a nonlinear relationship between phenotypes. We applied the procedure to a data set provided by a commercial Large White selection nucleus. The data file consisted of LS and NSB records of 4,462 parities. The results of the analysis clearly identified the location of the change points between different structural regression coefficients. The magnitude of these coefficients increased with LS, indicating an increasing incidence of LS on the NSB ratio. However, posterior distributions of correlations were similar across subpopulations (defined by the change points on LS), except for those between residuals. The heritability estimates of NSB did not present differences between recursive models. Nevertheless, these heritabilities were greater than those obtained for SMM (0.05) with a posterior probability of 85%. These results suggest a nonlinear relationship between LS and NSB, which supports the adequacy of a change-point recursive model for its analysis. Furthermore, the results from model comparisons support the use of recursive models. However, the adequacy of the different recursive models depended on the criteria used: the linear recursive model was preferred on account of its smallest deviance value, whereas nonlinear recursive models provided a better fit and predictive ability based on the cross-validation approach. 

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Nutrient and energy retention in weaned Iberian piglets fed diets with different protein concentrations

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Fifty-eight purebred castrated male Iberian (IB) piglets (initial BW 9.9 kg) were used in an experiment to determine the effect of dietary protein content (PC) and feeding level (FL) on the rates of BW gain, whole body protein deposition (PD), and energy utilization between 10 and 25 kg of BW using the serial slaughter method. Treatments followed a 4 × 2 factorial arrangement with 4 PC (201, 176, 149, and 123 g of CP/kg of DM) and 2 FL (0.95 and 0.70 × ad libitum) and 6 or 7 piglets per combination of treatments. All diets were formulated to have an optimal AA pattern. Six piglets were slaughtered at the start of the trial to estimate initial body composition. The experimental pigs were individually housed in an environmentally controlled room (27°C) until they reached 25 kg of BW, when they were slaughtered and analyzed for body composition. Positive linear effects of dietary PC on ADG, G:F, and gain:ME intake were observed. Piglets fed at the highest FL showed greater ADG, G:F, and gain:ME intake. An average increase was estimated to be 38.0 g of gain/MJ of ME intake. Protein deposition increased linearly from 35.6 to 50.9 g/d with increasing dietary PC. A daily increase was estimated to be 0.35 g of PD/g of CP intake. Although the maximal genetic potential for PD of the IB piglet was not attained, a maximal value of 59.9 g/d for whole-body PD was achieved when the diet provided 201 g of CP/ kg of DM and was fed at 0.95 × ad libitum. Piglets on the highest FL deposited on average 39% more body protein than restricted piglets. An average value of 4.39 g increase in PD/MJ of ME intake was obtained for diets containing 201 and 176 g of CP/kg of DM. Maintenance energy requirements and net efficiency of utilization of ME for growth, calculated by linear regression of ME intake on body retained energy, were 427 kJ/kg of BW0.75・d−1 and 0.552, respectively. The corresponding partial efficiencies of utilization of ME for protein and fat deposition were 0.378 and 0.672, respectively, considerably less than the accepted values for conventional pig breeds. Practical diets of the young IB piglet should contain at least 201 g of ideal CP/kg of DM.

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Effects of different moving devices at loading on stress response and meat quality in pigs

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Although there is increasing evidence regarding the negative welfare and meat quality implications of electric prod use for slaughter-weight pigs, this handling tool continues to be used. Therefore, the behavioral and physiological response and carcass and meat quality of 360 pigs being loaded onto a truck for transportation to slaughter according to 3 handling procedures were studied. The 3 handling procedures were 1) moving with an electric prod and board from the finishing pen to the truck (EP); 2) moving with a board and a paddle from the finishing pen to the truck (PAD); 3) moving with a board and a paddle from the finishing pen and using a compressed air prod in the ramp before going into the truck (CAP). A subpopulation of 144 pigs (48 pigs/treatment) was equipped with heart rate monitors. Blood samples were collected from the same animals at exsanguination for the analysis of creatine phosphokinase and lactate. Data were analyzed using an ANOVA for factorial design, with the animal as the experimental unit. Behavior was analyzed with MIXED model procedure with treatment as a fixed effect. During loading, EP pigs slipped and fell and overlapped more often, but stopped and attempted turns less often than CAP or PAD. With CAP, pigs made more 180° turns than with PAD or EP. Loading with EP led to more and longer vocalizations than loading with CAP or PAD. Loading took longest with CAP and was quickest with EP. Pigs handled with EP had a greater heart rate than those moved with PAD and CAP at loading, wait at loading, at unloading, and in lairage. Pigs loaded with EP had greater lactate concentrations in blood at exsanguination compared with pigs handled with CAP, with pigs loaded with PAD being intermediate. Furthermore, ultimate pH values in the semimembranosus and adductor muscles of EP pigs were greater compared with those from PAD and CAP pigs. Greater incidence of blood-splashed hams was found in EP pigs compared with PAD and CAP pigs. Therefore, considering animal welfare, carcass bruising, and blood splashes standpoints, EP should be replaced with PAD or CAP. However, additional research is necessary to identify methods that improve the loading efficiencies of PAD and CAP without adversely affecting animal welfare parameters.

Persistence of blood changes associated with alteration of the dietary electrolyte balance in commercial pigs after feed withdrawal, transportation, and lairage, and the effects on performance and carcass quality

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Increasing dietary electrolyte balance (dEB) has previously been shown to reduce the incidence of nonambulatory and noninjured swine, improve meat quality, and reduce the incidence of gastric ulcers. The objective of this study was to evaluate the effect of dEB under commercial conditions. Due to the variability in feed withdrawal, transport, and lairage conditions in the swine industry, it was necessary to determine first the persistence of blood changes during the marketing process after alteration of dEB. Sixteen pens of 8 crossbred barrows were assigned to a low (121 mEq/kg) or high (375 mEq/kg) dEB diet, calculated as Na+ + K+ − Cl−, to determine the persistence of blood changes associated with the alteration of dEB. Diets were formulated to meet or exceed NRC (1998) requirements for energy, protein, vitamins, and minerals. Dietary treatments were provided for ad libitum intake for 3 d before slaughter. Before transport, animals were fasted in the barn for approximately 10 h. After fasting, animals were shipped to the packing plant, rested for 8 h, and subsequently slaughtered. Initial and final BW of the animals were obtained. Blood was sampled at baseline (2 d before administration of diets), before feed withdrawal (0 h), after feed withdrawal (10 h), and at exsanguination (20 h). Consumption of the high dEB diet for 3 d resulted in an increase in blood TCO2, HCO3−, and base excess and a decrease in Cl− and anion gap. These differences, however, were not maintained for any of the blood components after the 10-h feed withdrawal. Increasing dEB had no adverse effects on growth performance, meat quality, or carcass yield and did not decrease pars esophageal ulcer scores. This study demonstrated that the effect of dEB on blood components was not maintained after a 10-h feed withdrawal. Therefore, it is likely that the ability of the animal to withstand any increased metabolic acid load associated with the stress of transport was lost after feed withdrawal. Further research is needed to determine the effects of dEB alteration in animals that have not been fasted before shipment and using diets with a larger difference in dEB.

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Estimation of the standardized ileal digestible valine-to-lysine ratio in 13- to 32-kilogram pigs

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Three experiments were conducted to determine the optimum standardized ileal digestible Val-to-Lys (SID Val:Lys) ratio for 13- to 32-kg pigs. In Exp. 1, 162 pigs weaned at 17 d of age (8 pens/treatment) were used, and a Val-deficient basal diet containing 0.60% l-Lys・HCl, 1.21% SID Lys, and 0.68% SID Val was developed (0.56 SID Val:Lys). Performance of pigs fed the basal diet was inferior to a corn-soybean meal control containing only 0.06% l-Lys・HCl, but was fully restored with the addition of 0.146% l-Val to the basal diet (68% SID Val:Lys). In Exp. 2, 54 individually housed barrows (21.4 kg) were utilized in a 14-d growth assay. Pigs were offered a similar basal diet (1.10% SID Lys), ensuring Lys was marginally limiting with no supplemental l-Val (55% SID Val:Lys). The basal diet was fortified with 4 graded levels of l-Val (0.055% increments) up to a ratio of 75% SID Val:Lys. In Exp. 3, 147 barrows (13.5 kg) were fed identical diets, only with 1 additional level at a SID Val:Lys of 80% and fed for 21 d. In Exp. 2 and 3, a high protein, control diet was formulated to contain 1.10% SID Lys and 0.20% l-Lys・HCl. In Exp. 2, linear effects on ADG (713, 750, 800, 796, and 785 g/d) and G:F were observed with increasing SID Val:Lys, characterized by improvements to a ratio of 65% and a plateau thereafter. In Exp. 3, quadratic improvements in ADG (600, 629, 652, 641, 630, and 642 g/d) and G:F were observed with increasing SID Val:Lys, as performance increased to a ratio of 65% but no further improvement to a ratio of 80%. Pigs fed the control diet did not differ from those fed a ratio of 65% SID Val:Lys in Exp. 2, but did have improved G:F in Exp. 3. To provide a more accurate estimate of the optimum SID Val:Lys, data from Exp. 2 and 3 were combined. With single-slope broken-line methodology, the minimum ratio estimate was 64 and 65% SID Val:Lys for ADG and G:F, respectively. With combined requirement estimates, the data indicate that a SID Val:Lys of 65% seems adequate in maintaining performance for pigs from 13 to 32 kg.

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Effects of spray-dried animal plasma on serous and intestinal redox status and cytokines of neonatal piglets

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The study investigated the effects of dietary supplementation with spray-dried animal plasma (SDAP) on growth performance, intestinal morphology, as well as serum and intestinal cytokines and antioxidant indicators of artificially reared neonatal piglets. Three diets, 1) control (a fish meal basal diet), 2) SDAP (containing 10% SDAP), and 3) autoclaved SDAP (auSDAP; containing 10% auSDAP), were fed to 36 weaned piglets (3 d old), which were randomly allotted to 3 groups. At 21 d of age, blood and intestinal mucosal samples were collected from all piglets after they were slaughtered. Compared with the control, both SDAP and auSDAP improved ADFI and duodenal villus height of piglets, whereas SDAP increased ADG and duodenal villus height to crypt depth ratio. Piglets fed SDAP and auSDAP had reduced malondialdehyde (MDA) content in mucosa. The concentration of serum MDA was decreased and mucosal catalase (CAT) activities were increased in piglets fed SDAP diet than those fed the control diet. In the mucosa, both SDAP and auSDAP decreased tumor necrosis factor α, IL-6, transforming growth factor β, and soluble IL-2 receptor contents. Mucosal IL-1β was decreased in SDAP compared with auSDAP and control groups. The SDAP and control groups had increased mucosal IL-2 compared with auSDAP group. The cytokines in serum were not affected by SDAP and auSDAP. The results indicate that both SDAP and auSDAP improved the growth performance of neonatal piglets, whereas the SDAP had a greater effect. The benefits of SDAP probably resulted from the promotion of the intestinal development, which were accompanied by the increased antioxidant capacity and the decreased production of inflammatory factors in the intestinal mucosa.

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