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The study aimed to assess the effects of vitamin E (VE) supplementation and fat source on fatty acid (FA) composition, VE concentrations, and antioxidant capacity in plasma and tissues of pigs fed to a heavy slaughter weight (150 kg). A total of 64 pigs (32 barrows, 32 gilts; 28.41 ± 0.83 kg) were blocked by sex and weight, and randomly assigned to one of eight dietary treatments (n = 8 per treatment) in a 4 × 2 factorial arrangement. Fat sources included corn starch (CS), 5% tallow (TW), 5% distiller's corn oil (DCO), and 5% coconut oil (CN); VE supplementation levels were 11 and 200 ppm. Five-phase diets were formulated to meet requirement estimates of NRC (2012) and fed to pigs for each period of 25 kg from 25 to 150 kg. Increasing VE supplementation level increased C16:1 (P 0.05) content but decreased C20:0 (P 0.05) content in backfat and belly fat, while in liver, it increased C17:0 (P 0.05) but decreased C18:0 (P 0.05). Compared to the pigs fed the CS diet, the pigs fed the CN diet had greater (P 0.05) content of total saturated FA, the pigs fed the DCO diet had greater (P 0.05) content of total polyunsaturated FA content and iodine value, and the pigs fed the TW diet had greater (P 0.05) content of total monounsaturated FA in backfat, belly fat, and liver. Plasma VE concentrations increased linearly (P 0.05) with increasing length of feeding but faster (P 0.05) in the pigs fed the CN and TW diets compared with the CS and DCO diets within the 200 ppm VE level; the pigs fed the DCO diet had the highest plasma VE concentrations (P 0.05) from Phase 2 to Phase 5 within the 11 ppm VE level. The VE concentrations in liver and loin muscle (P 0.05) increased with increasing dietary VE level from 11 to 200 ppm, but it was not affected by dietary fat source. There was no effect of VE supplementation and fat source on antioxidant capacity in plasma and liver except that pigs fed the DCO diet had greater liver SOD activity (P 0.05) than the pigs fed the CN diet. In conclusion, dietary VE supplementation did not affect FA profile in backfat, belly fat, and liver consistently, while dietary FA composition with different fat sources affected much of the FA profile in backfat, belly fat, and liver. The higher level of VE supplementation increased liver and muscle VE concentrations and dietary fat sources affected plasma VE concentrations differently (P 0.05), wherein the TW and CN diets increased the VE absorption greater than the DCO diet.The study evaluated vitamin E (VE) supplementation and fat source on fatty acid (FA) composition and VE concentrations in pigs. Three fat sources with distinctive fatty acid profiles were used; VE levels were 11 (the requirement estimate) and 200 (a high level to assure any responses could be seen) ppm. Increasing VE affected very few FA in tissues. Compared with the control pigs, pigs fed the coconut oil diet had greater content of saturated FA, pigs fed the distiller’s corn oil diet had greater content of polyunsaturated FA content, and pigs fed the tallow diet had greater content of monounsaturated FA in tissues. Plasma VE increased with increasing length of feeding but faster in pigs fed the coconut oil and tallow diets compared with the control and distiller’s corn oil diets when the 200 ppm VE level was fed; pigs fed the distiller’s corn oil diet had the highest plasma VE concentrations when the 11 ppm VE level was fed. In conclusion, dietary VE did not affect FA profile in backfat, belly fat, and liver consistently, while different dietary fat sources affected much of the FA profile in tissues. The higher level of VE, as expected, increased liver and muscle VE concentrations.

The study aimed to assess the effect of vitamin E (VE) supplementation and fat source on growth performance, lean growth, organ size, carcass characteristics, and pork quality of pigs at a heavy slaughter weight of 150 kg. A total of 64 pigs (32 barrows and 32 gilts; 28.41 ± 0.83 kg) were blocked by sex and body weight, and randomly assigned to one of eight dietary treatments (n = 8 per treatment) in a 4 × 2 factorial arrangement with main effects of fat source (corn starch [CS; no fat added], 5% tallow [TW], 5% distiller's corn oil [DCO], and 5% coconut oil [CN]) and VE supplementation level (11 and 200 ppm). Five-phase diets were formulated to meet requirement estimates of NRC and fed to pigs with each period of 25 kg from 25 to 150 kg. Increasing dietary VE supplementation from 11 to 200 ppm tended to increase average daily gain (ADG) in phase 5 (P = 0.08), and gain to feed ratio (G/F) in phase 4 (P = 0.06) and phase 5 (P = 0.06) resulting in increased G/F in the overall period (P = 0.10). Compared with the pigs fed the CS diet in the overall period, the pigs fed DCO diets had greater ADG (P0.05), the pigs fed the TW and CN diets had lower average daily feed intake (P0.05), and the pigs fed the fat-added diets had greater G/F (P0.05). Belly firmness was greatest in the pigs fed the CN diet and lowest in those fed the DCO diet (P0.05). Increasing dietary VE level from 11 to 200 ppm increased absolute and relative liver weight, absolute ham yield (P0.05), and tended to increase the relative yield of picnic shoulder (P = 0.07) and ham (P = 0.06) and the pigs fed the corn oil diet tended to have greater belly yield (P = 0.08) than the other fat treatments. Increasing dietary VE level increased 45-min pH and ΔpH at slaughter but decreased a* value, chroma (P0.10), and belly depth (P0.05). However, no effects of VE supplementation and fat source were observed on the other carcass traits and meat quality measurements. In conclusion, increasing dietary VE level from 11 to 200 ppm slightly increased growth rate and feed efficiency in the late finishing periods, and the addition of fat increased feed efficiency and backfat thickness, decreased lean content, and altered belly firmness. While there were some effects of VE supplementation and fat source observed on organ weight, primal cuts, carcass traits, and meat quality, there was no strong evidence that VE supplementation and fat source materially affected these measurements except for belly firmness.The study aimed to assess the effect of vitamin E (VE) supplementation and fat source on growth performance, carcass characteristics, and pork quality of pigs slaughtered at 150 kg. Fat sources included corn starch (no fat added), or 5% tallow, distiller’s corn oil (DCO), or coconut oil (CN); VE supplementation levels were 11 and 200 ppm. Increasing dietary VE from 11 to 200 ppm tended to increase the efficiency of conversion of feed to body weight gain for the overall study period. The pigs fed the DCO diet had greater backfat depth at slaughter. Belly (from which bacon is made) firmness was greatest in the pigs fed the CN diet and lowest in those fed the DCO diet. In conclusion, increasing dietary VE levels from 11 to 200 ppm slightly increased growth rate and feed efficiency, and the addition of fat increased feed efficiency and backfat thickness, decreased lean muscle content, and altered belly firmness. While there were some effects of VE supplementation and fat source, there was no strong evidence that VE supplementation and fat source materially affected these measurements except for belly firmness.

At 8-wk post-weaning, pens of split-sexed pigs (26.0 ± 0.25 pigs/pen; 31.3 ± 0.11 kg; DNA genetics) being housed in a commercial research unit were randomly assigned to one of two dietary treatments to compare the growth performance and efficiency of the system’s commercial nutritional program that included narasin (Skycis™, Elanco Animal Health, Greenfield, IN) at 13.6 g/tonne to a product (2 kg/tonne) containing a combination of bioactive peptides and enzymes (PEP; Peptiva® Optimo, Vitech Bio-Chem Corporation, Orange, CA). Dietary treatments were fed through 4 phases based on feed budgets. Pens were weighed bi-weekly through 59-d on test. There were 12 replications or pens per treatment. Feed was delivered and measured using a Feed Logic system and weigh backs were conducted utilizing a calibrated ruler. Average daily gain and feed intake were calculated on a pen basis. Data were analyzed as a mixed model with dietary treatment, gender, and treatment x gender interaction included. There were no interactions reported (P ≥ 0.0965). During the study pigs performed at or above their commercial counterparts. Overall, body weight, ADG, and ADFI were not impacted by treatment, but pigs fed PEP had an 2.1% improvement in feed efficiency compared to the narasin fed pigs. These results indicate that feeding bioactive peptides plus enzymes may improve feed efficiency without the need of an ionophore in the grower period in a commercial swine facility.

Two studies were conducted to determine if corn can be replaced by wheat and if wheat can be combined with corn distillers dried grains with solubles (DDGS) and a commercial carbohydrase in phase 2 and 3 nursery diets. In Exp. 1, 144 pigs were blocked by weight and randomly allotted to 6 dietary treatments: 0%, 20%, 40%, 60%, 80%, and 100% wheat replacing corn. In Exp. 2, 210 pigs were blocked by weight and randomly allotted to 5 dietary treatments: control diet (CO); 30% wheat (W); wheat with carbohydrase (W + Enz); 30% wheat with 30% corn DDGS (WCD); and WCD with carbohydrase (WCD + Enz). In both experiments, pigs were fed a standard phase 1 diet from d 0 to 7 post-weaning. In both experiments, TiO2 was used as an indigestible marker to determine apparent total tract digestibility (ATTD) of N, ether extract (EE), gross energy (GE), P, neutral detergent fiber (NDF), and acid detergent fiber (ADF). In Exp. 1, there was a quadratic effect of increasing wheat on overall (d 0–35) average daily gain (ADG, P

A total of 135 pigs (initial weight=7.2±0.2 kg) were used to evaluate the effect of xylanase (XYL) and β-glucanase (BGL) alone or in combination (XB) on growth performance and nutrient digestibility in nursery pigs fed diets with corn/SBM and 30% corn distillers dried grains with solubles (CDDGS). Pens (n=30, 4–5 pigs per pen) were randomly assigned to one of five treatments: positive control (PC, Corn/SBM+0% CDDGS), negative control (NC, 30% CDDGS replacing a portion of the corn and SBM with no enzyme addition), negative control+4000 unit/kg xylanase (XYL), negative control +450 unit/kg β-glucanase (BGL), and negative control+4000 unit/kg xylanase+450 unit/kg β-glucanase (XB). All pigs were fed a common phase 1 diet for one week post-weaning, and were switched to experimental diets in phase 2 (d7-21) and phase 3 (d21-35). Pigs fed the NC diet had reduced growth rate (P

The study objective was to assess the contribution of fat source and vitamin E (VE) supplementation on growth performance, antioxidant status, and fatty acid profile in the liver of pigs at heavy slaughter weight (148.09 ±1.64 kg). A total of 72 individually-fed pigs (36 barrows, 36 gilts; 28.55 ±1.16 kg) were randomly assigned to 12 dietary treatments in a 2 × 6 factorial arrangement. Fat treatments were tallow and corn-oil. The VE treatments included four levels of α-tocopheryl-acetate (ATA; 11, 40, 100, and 200 ppm) and two levels of mixed tocopherols (primarily γ-tocopherol; 40 and 100 ppm). Liver samples were collected at slaughter. Data analysis were performed by ANOVA using GLM in SAS. No effect of dietary fat sources, isoforms of VE, and levels of γ-tocopherol were detected on growth performance or liver antioxidant status (GSH, GSSG, SOD, and MDA). Increasing dietary ATA linearly increased overall ADG (0.98, 1.02, 1.02, and 1.08 kg/day; P = 0.02) from 28 to 150 kg; overall ADG of pigs fed γ-tocopherol-diets was 1.07 and 1.04 kg/day, respectively. An interaction between fat sources and ATA was observed on cumulative ADG during Phase1-3 (28-100 kg; P = 0.04) and Phase1-4 (28-125 kg; P = 0.03) wherein pigs fed corn-oil-diet, but not tallow-diet, had increased ADG with increased dietary ATA. Increasing dietary ATA quadratically increased SOD activity (P < 0.05; highest at 100 ppm), and quadratically decreased MDA content (P < 0.05; lowest at 40 ppm) in the liver. Liver fatty acid profile was affected by fat source (P < 0.05) but not VE treatment, pigs fed corn-oil-diets had less SFA (34.23 vs. 35.45%; P = 0.02) and MUFA (11.98 vs. 18.38%; P < 0.0001), but more PUFA (49.14 vs. 40.78%; P < 0.0001) than pigs fed tallow-diets in the liver. Beneficial effects of dietary VE supplementation were observed on growth performance and antioxidant status of pigs under conditions of this study.

Green tea and its catechins have been shown to ameliorate high fat diet-induced oxidative stress and hyperlipidemia. However, low bioavailability of catechins limits their therapeutic potential. Lemon juice (LJ) has been suggested to enhance the bioavailability of catechins in vitro. This study investigated the antioxidative and hypolipidemic efficacy of a single dose of green tea extract (GTE) or GTE plus LJ (GTE + LJ) in high-fat diet fed pigs. Sixteen pigs ingested a single dose of GTE (190 mg/kg/day) or GTE + LJ (0.75 mL/kg/day) mixed with low-fat (LF, 5% fat) or high-fat (HF, 22% fat) diets and blood samples were collected for 24 h. Plasma catechin level peaked at two hours, and gradually returned to baseline after six hours following the intake. The addition of LJ significantly increased plasma catechin level. The diet containing GTE did not lower plasma cholesterol and triacylglycerol (TG) concentrations, superoxide dismutase (SOD) and catalase activity, or malondialdehyde concentration in 24 h in HF-fed pigs. Addition of a single dose of LJ, however, significantly decreased plasma TG level in LF groups but did not cause further changes on any other markers compared to the GTE alone. Our findings indicate limited effect of a single meal containing GTE on plasma antioxidant enzymes, lipid profile, and lipid peroxidation in pigs and no significant synergistic/additive action of adding LJ to GTE within 24 h in pigs. A study with a longer treatment period is warranted to further understand the potential role of GTE in reducing HF diet-induced oxidative stress and the possible synergistic role of LJ.

OBJECTIVES: Lutein (LUT) and docosahexaenoic acid (DHA) accumulate in the brain and are positively associated with neurocognitive function. Maternal nutritional status in pregnancy and lactation impact the brain development of the offspring. The objective of this study was to determine the impact of maternal supplementation of LUT and DHA during the perinatal period on the cognitive outcomes and regional brain volumes of the offspring. METHODS: Pregnant sows (n = 11) were fed a control diet only (CON), CON containing LUT (LUT, 2 mg/kg BW/day), or CON containing DHA (DHA, 75 mg/kg BW/day) from late gestation to lactation period for 60 days. At weaning (21d), piglets (n = 4/litter, total n = 44) underwent open field test (OFT) and object recognition test (ORT) to assess exploratory behaviors and memory formation, respectively. In addition, magnetic resonance imaging (MRI) was performed (n = 12) to measure the volumes of 19 brain regions. RESULTS: In the OFT, piglets from LUT-fed sows showed 96% higher sniffing wall frequency compared to controls (P = .022), demonstrating that maternal LUT supplementation may enhance the exploratory behavior of its offspring at weaning. In the ORT, male LUT pigs (P = .034), and both male and female DHA pigs (P = .016, P = .035, respectively) spent significantly longer time exploring the novel object than familiar object, while controls spent similar time with both objects (P > .05), suggesting that maternal supplementation with either LUT or DHA during the perinatal period may improve hippocampal-dependent memory formation of the offspring. MRI volumetric assessments showed that piglet brains were composed of 63.4% cortex, 11.39% cerebellum, 2.76% thalamus, 1.84% hippocampus, and 4.63% olfactory bulb and other subcortical regions. Maternal LUT or DHA supplementation did not affect the volumes of these regions except for the internal capsule. The volume of the internal capsule was significantly larger in the DHA pigs compared to controls (P = .026). CONCLUSIONS: Maternal supplementation of LUT or DHA may increase exploratory behaviors and memory function of the offspring at weaning without affecting the volume of major brain structures. Further analysis is ongoing to elucidate the mechanisms of the neurocognitive changes by assessing functional connectivity of brains via functional MRI. FUNDING SOURCES: The study was supported by Georgia Experimental Agricultural Station, HATCH #GEO00795 and Faculty research grant from Office or Research at the UGA. DHA was kindly provided by DSM, Inc.

The objective of this study was to determine the effect of altering dietary levels of manganese and selenium on growth performance and MnSOD specific activity. Weaned piglets were blocked by weight (n = 216; 5.21 ± 1.17 kg; 21 ± 3 d) and sex (2 barrows and 2 gilts/pen). Pens within a block were randomly assigned to dietary treatments in a factorial design with main effects of Se (0.1 and 0.3 ppm) and Mn (0, 12, and 24 ppm). Diets (n = 9 pens/treatment) were fed in three phases (P1 = d 1–7, P2 = d 7–21, P3 = d 21–35). Pigs and orts were weighed weekly and pigs were bled on d 0, 7, 21, and 35 for analysis of specific activity of red blood cell MnSOD. Data were analyzed as 2x3 factorial design via SAS PROC GLM. There were no Se effects or Mn x Se interactions observed. There was a linear increase (P < 0.05) in overall ADG (397, 424, and 438 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). There was a linear trend (P < 0.1) in overall ADFI (557, 560, 592 g day-1pig-1 for 0, 12, 24 ppm Mn, respectively). Feed efficiency (d 0–35) across increasing Mn levels were 0.71, 0.76, 0.74 (P > 0.1). MnSOD activity in RBC increased from d 0–7, peaked on d 7 and decreased to d 35. On d 7, diets with 12 and 0 ppm Mn had significantly increased (P < 0.05) MnSOD activity (0.91 and 0.87 IU mg-1 protein, respectively) compared to diets with 24 ppm Mn (0.67 IU mg-1 protein). The dietary treatment that best maintained MnSOD activity was 0.3 ppm Se and 12 ppm Mn supplemented, while ADG was maximized in the diet with 0.3 ppm Se and 24 ppm Mn supplementation.

The objective of this study was to determine the performance response to changes in dietary fat, protein, and fiber content in finishing barrows while maintaining a constant apparent ileal digestible (AID) Lys to metabolizable energy (ME) ratio (AID Lys:ME). The experiment was conducted in 2 trials, each containing 25 individually penned pigs. In both trials, barrows (initial wt=85.3 kg) were blocked by weight and assigned to one of five experimental diets (0.40, 0.44, 0.48, 0.52, and 0.56% digestible Lys) with a constant AID Lys:ME (1.44 g/MCal). Lysine content was changed by altering the proportions of corn and soybean meal and energy was altered by the addition or removal of cellulose and fat. Diets contained 0.2% titanium dioxide as a digestibility marker. Pigs were fed experimental diets for 28 d, and body weights, feed intakes, and ultrasound measurements of tenth rib backfat (BF) and loin eye area (LEA) were recorded on d 14 and 28. Blood samples were taken on d 28 to determine serum urea nitrogen (SUN), insulin, T3, and T4. A quadratic effect of increasing dietary Lys was seen on ADG on d 28 showing that the addition of Lys increased gain (P

Epidemiologic studies associate maternal docosahexaenoic acid (DHA)/DHA-containing seafood intake with enhanced cognitive development, although, it should be noted that interventional trials show inconsistent findings. We examined perinatal DHA supplementation on cognitive performance, brain anatomical and functional organization, and the brain monoamine neurotransmitter status of offspring using a piglet model. Sows were fed a control (CON) or a diet containing DHA (DHA) from late gestation throughout lactation. Piglets underwent an open field test (OFT), an object recognition test (ORT), and magnetic resonance imaging (MRI) to acquire anatomical, diffusion tensor imaging (DTI), and resting-state functional MRI (rs-fMRI) at weaning. Piglets from DHA-fed sows spent 95% more time sniffing the walls than CON in OFT and exhibited an elevated interest in the novel object in ORT, while CON piglets demonstrated no preference. Maternal DHA supplementation increased fiber length and tended to increase fractional anisotropy in the hippocampus of offspring than CON. DHA piglets exhibited increased functional connectivity in the cerebellar, visual, and default mode network and decreased activity in executive control and sensorimotor network compared to CON. The brain monoamine neurotransmitter levels did not differ in healthy offspring. Perinatal DHA supplementation may increase exploratory behaviors, improve recognition memory, enhance fiber tract integrity, and alter brain functional organization in offspring at weaning.

One-day-old chicks were assigned one of four dietary treatments in a 2 &times, 2 factorial design in which the main effects were diet (adequate vs. low protein) and the addition of protease (0 vs. 200 g/1000 kg of feed). Chick performance (days 0&ndash, 14) was recorded and their excreta were analyzed for short chain fatty acids, ammonia, and composition of the microbiota using 16S rRNA gene sequencing. Birds fed the low protein diet had lower body weight gain and poorer overall feed conversion ratio (FCR) (p 0.04), however, these parameters were not affected by the inclusion of protease (p 0.27). Protease inclusion did not affect any particular bacterial genus in the excreta, but it increased the total number of observed OTUs (p = 0.04) and Faith&rsquo, s phylogenetic diversity (p = 0.05). Abundance of Proteus and Acinetobacter were lower in the excreta of chicks fed the low protein diet (p = 0.01). Abundance of Bacteroides was associated with poorer FCR, while Proteus was associated with improved FCR (p 0.009). Although diet had a stronger impact than protease on chick performance, both diet and protease yielded some changes in the intestinal microbiotas of the birds.

The purpose of this study is to evaluate the accuracy of an oscillometric blood pressure monitor in anesthetized pigs. Invasive blood pressure (IBP) and noninvasive blood pressure (NIBP) measurements were taken using a DRE Waveline Pro multiparameter monitor at four different time points in 17 pigs undergoing injectable anesthesia. NIBP measurements were taken on both the thoracic and pelvic limbs. Bland Altman analysis was used to assess agreement between methods and a linear mixed-effects model was used to evaluate the effect of cuff position and blood pressure on bias. Invasive systolic arterial pressure (SAP) ranged between 112 and 161 mmHg (mean ± SD: 138.8 ± 13.3; median: 139.5). Invasive diastolic arterial pressure (DAP) ranged between 60 and 104 mmHg (mean ± SD: 86.0 ± 9.1; median: 87.0). Invasive mean arterial pressure (MAP) ranged between 79 and 121 mmHg (mean ± SD: 103.2 ± 9.3; median 103.0). Only the diastolic and mean measurements obtained from the pelvic limb met criteria outlined by the American College of Internal Medicine for required accuracy of NIBP monitors. Bias was significantly higher in the thoracic limb in comparison to the pelvic limb and was significantly higher at blood pressures above median. In general, NIBP measurements underestimated IBP measurements. In conclusion, the use of the DRE Waveline Pro to assess NIBP in anesthetized pigs may be useful in monitoring trends in mean and diastolic blood pressure and is most accurate when used on the pelvic limb.

The use of agricultural animals in biomedical research is increasing. Their overall size and metabolic rate, organ size, longer gestation period, and other physiological similarities make them good candidates for animal models of human disease. There are a number of special considerations for use of traditional farm animals for biomedical research. Differences in physical plant infrastructure, handling equipment, training of personnel, and potential zoonoses are some of the important considerations when traditional farm animals are used in biomedical research. This article provides an overview of some of the special considerations for using traditional agricultural animals in biomedical research. With the growing need for improved translational research, it is reasonable to predict significant growth in these animal models.

A cooperative study comprising growth performance, bone mineralization, and nutrient balance experiments was conducted at 11 stations to determine the standardized total-tract digestible (STTD) P requirement of 20-kg pigs using broken-line regression analysis. Monocalcium phosphate and limestone were added to a corn-soybean meal-based diet at the expense of cornstarch to establish 6 concentrations of STTD P from 1.54 to 5.15 g/kg in increments of 0.62 g/kg at a constant Ca:total P of 1.52:1.0. Diets were fed to 936 pigs (average initial BW of 19 kg) in 240 pens for 20 replicate pens of barrows and 20 replicate pens of gilts per diet. As STTD P increased from 1.54 to 5.15 g/kg of the diet for d 0 to 14, 14 to 28, and 0 to 28, the ADG, ADFI, and G:F increased ( < 0.01). Barrows gained and ate more ( < 0.05) than gilts during d 14 to 28 and 0 to 28. There was no interaction between sex and STTD P concentration for any of the growth performance response criteria. There were both linear and quadratic increases ( < 0.05) in mineral density and content of ash, Ca, and P in the femur expressed as a percentage of dry, fat-free metacarpal as dietary STTD P increased. Furthermore, the maximum load of the femur and mineral density and content and maximum load as well as the Ca and P expressed as a percentage of metacarpal ash linearly increased ( < 0.01) with increasing dietary concentrations of STTD P. There were both linear and quadratic increases ( < 0.01) in apparent digestibility and retention of P with increasing concentrations of STTD P in the diets. Digestibility and retention of Ca linearly ( < 0.01) increased with increasing dietary concentrations of STTD P. Breakpoints determined from nonlinear broken-line regression analyses revealed estimates of 4.20 ± 0.102, 3.20 ± 0.036, or 3.87 ± 0.090 g/kg for ADG during d 0 to 14, 14 to 28, or 0 to 28, respectively. Corresponding estimates using G:F as the response criterion were 4.34 ± 0.146, 3.38 ± 0.139, or 4.08 ± 0.195 g/kg. When mineralization of the femur was used as criteria of response, estimates of STTD P requirement were 4.28, 4.28, or 4.34, g/kg for mineral density, mineral content, or maximum load, respectively. Using mineralization of the metacarpal as criteria of response, estimates of STTD P requirement ranged from 3.5 to 5.0 g/kg depending on the metacarpal response criteria. The study provided empirical estimates of STTD P requirements of 20- to 40-kg pigs.