Formulating diets based on digestible calcium instead of total calcium does not affect growth performance or carcass characteristics,but microbial phytase ameliorates bone resorption caused by low calcium in diets fed to pigs from 11 to 130 kg

An experiment was conducted to test the hypothesis that the requirement for Ca expressed as a ratio between standardized total tract digestible (STTD) Ca and STTD P obtained in short-term experiments may be applied to pigs fed diets without or with microbial phytase from 11 to 130 kg. In a 5-phase program, 160 pigs (body weight: 11.2 ± 1.8 kg) were randomly allotted to 32 pens and 4 corn–soybean meal-based diets in a 2 × 2 factorial design with 2 diet formulation principles (total Ca or STTD Ca), and 2 phytase inclusion levels (0 or 500 units/kg of feed) assuming phytase released 0.11% STTD P and 0.16% total Ca. The STTD Ca:STTD P ratios were 1.40:1, 1.35:1, 1.25:1, 1.18:1, and 1.10:1 for phases 1 to 5, and STTD P was at the requirement. Weights of pigs and feed left in feeders were recorded at the end of each phase. At the conclusion of phase 1 (day 24), 1 pig per pen was euthanized and a blood sample and the right femur were collected. At the end of phases 2 to 5, a blood sample was collected from the same pig in each pen. At the conclusion of the experiment (day 126), the right femur of 1 pig per pen was collected and carcass characteristics from this pig were measured. No interactions were observed between diet formulation principle and phytase inclusion for growth performance in any phase and no differences among treatments were observed for overall growth performance. Plasma Ca and P and bone ash at the end of phase 1 were also not influenced by dietary treatments. However, on day 126, pigs fed nonphytase diets formulated based on total Ca had greater bone ash than pigs fed STTD Ca-based diets, but if phytase was used, no differences were observed between the 2 formulation principles (interaction P < 0.05). At the end of phases 2 and 3, pigs fed diets without phytase had greater (P < 0.05) plasma P than pigs fed diets with phytase, but no differences were observed at the end of phases 4 and 5. A negative quadratic effect (P < 0.05) of phase (2 to 5) on the concentration of plasma Ca was observed, whereas plasma P increased (quadratic; P < 0.05) from phases 2 to 5. However, there was no interaction or effect of diet formulation principle or phytase inclusion on any carcass characteristics measured. In conclusion, STTD Ca to STTD P ratios can be used in diet formulation for growing-finishing pigs without affecting growth performance or carcass characteristics and phytase inclusion ameliorates bone resorption caused by low dietary Ca and P.     

Effects of single or carbohydrases cocktail in low-nutrient-density diets on growth performance, nutrient digestibility, blood characteristics, and carcass traits in growing–finishing pigs

This study was conducted to evaluate the effects of single or carbohydrases cocktail in low-nutrient-density diets on growth performance, nutrient digestibility, blood characteristics, and carcass traits of growing–finishing pigs. A total of 96 pigs with an average initial BW of 47.50 ± 1.25 kg were used in this 8-week growth trial. Pigs were randomly allocated to 1 of the 4 treatments according to its BW and sex (4 pigs/pen, 6 replicate pens/treatment). The diets included: 1) control (CON) corn–soybean meal diet (DE, 3400 kcal/kg; CP, 17%), 2) low-nutrient-density (LC) diet with 6% DDGS and 5% tapioca (DE, 3280 kcal/kg; CP, 15%), 3) LC + 0.05% β-mannanase (LCS), and 4) LC + 0.05% enzyme mixture (LCM). The LC treatment had a lower ADG, and G/F compared to the other treatments in 0–4 weeks and the overall period of the feeding trial (P < 0.05). The ADFI were decreased in LC, LCS, and LCM groups related to CON (P < 0.05). The LCS treatment had higher DM digestibility than pigs in both the LC and LCM groups (P < 0.05) on 4 weeks while LCM improved N and energy digestibility compared to LC treatment. Blood urea nitrogen and creatinine values were not affected by the experimental treatments. After the feeding period, pigs (2 per pen) which reached marketing BW were collected meat samples from slaughter house. Backfat thickness was decreased in LC, LCS and LCM groups (P < 0.05). No numerical differences were observed in meat color, pH value and water holding capacity among four treatments. In conclusion, the results of this study indicate that single or carbohydrases cocktail in low-density diets can partially improve ADG, G/F, nutrient digestibility, and meat quality in finishing pigs, which can counteract the negative effects caused by the decreased nutrient concentration.     

Effects of dietary supplemental phytoncide instead of zinc oxide on growth performance,nutrient digestibility,blood profiles,and faecal microflora in growing pigs

This study was aimed to evaluate the effect of phytoncide (PTC) instead of zinc oxide on growth performance, blood profile, nutrient digestibility and faecal microflora in growing pigs. A total of 120 growing pigs [(Landrace × Yorkshire) × Duroc] with initial body weight 24.48 ± 1.62 kg were randomly assigned to four dietary treatments for a 6 weeks feeding trials, the treatments as follow: CON (base diet),ZO (CON + 0.03% Zinc Oxide), PTC1 (CON + 0.5% PTC), PTC2 (CON + 1.0% PTC). Compared to basal diet, during weeks 1–3, 3–6, and overall experimental period, the ADG of growing pigs fed phytoncide diet trend to be increased, and fed ZO diet was significantly increased (p < 0.05). During weeks 3–6 and overall experiment period, pigs fed the ZO diet showed improvement in feed intake compared to pigs fed basal diet as a trend. Compared with basal diet, the pigs receiving phytoncide diet significantly increased the digestibility of DM and reduced the concentration of aspartate transaminase in pigs receiving 1.0% phytoncide diet. These results suggested that dietary supplement of phytoncide, Korean pine extract, could be used as an alternative to zinc oxide by decreasing detoxify to soil and plants without influencing the performance of growing pigs. Further study is needed to determine the systemic estimation of the dose of phytoncide.     

Effects of fermented mushroom (Flammulina velutipes) by‐product diets on growth performance and carcass traits in growing‐fattening Berkshire pigs

This study was conducted to investigate effects of fermented mushroom (Flammulina velutipes) by‐product diets on the growth performance and carcass traits in growing‐fattening Berkshire pigs. The fermented diets mainly contained 40.0% mushroom by‐product, 20.0% formula feed, 26.0% rice bran and supplemental 0.1% probiotics. The mixed ingredients were fermented for 5 days at room temperature. Berkshire pigs (n = 225) were divided into five groups and three replications. The basal diets (C) were substituted by 10% (T1), 30% (T2), 50% (T3) and 70% (T4) fermented mushroom by‐product diets. Crude protein concentration and total calorie in fermented diets were significantly increased (P < 0.05) at the end of fermentation days compared with initial fermentation day. Body weight gain, feed efficiency and carcass weight were significantly lower (P < 0.05) in the T2, T3 and T4 groups than in the control group. Carcass grade was significantly better (P < 0.05) in the pigs fed fermented diets than in the pigs fed control diet and the ratio of high grade (1 plus 2 grades) was higher in the fermented diet groups compared with the control group. Therefore, although a diet of fermented mushroom by‐product decreased growth performance and feed efficiency, it improved the carcass grade in Berkshire pigs.     

Influence of a novel consensus bacterial 6-phytase variant on mineral digestibility and bone ash in young growing pigs fed diets with different concentrations of phytate-bound phosphorus

A 20-d experiment was conducted to test the hypothesis that phytase increases nutrient digestibility, bone ash, and growth performance of pigs fed diets containing 0.23%, 0.29%, or 0.35% phytate-bound P. Within each level of phytate, five diets were formulated to contain 0, 500, 1,000, 2,000, or 4,000 phytase units (FTU)/kg of a novel phytase (PhyG). Three reference diets were formulated by adding a commercial Buttiauxella phytase (PhyB) at 1,000 FTU/kg to diets containing 0.23%, 0.29%, or 0.35% phytate-bound P. A randomized complete block design with 144 individually housed pigs (12.70 ± 4.01 kg), 18 diets, and 8 replicate pigs per diet was used. Pigs were adapted to diets for 15 d followed by 4 d of fecal collection. Femurs were collected on the last day of the experiment. Results indicated that diets containing 0.35% phytate-bound P had reduced (P < 0.01) digestibility of Ca, P, Mg, and K compared with diets containing less phytate-bound P. Due to increased concentration of total P in diets with high phytate, apparent total tract digestible P and bone ash were increased by PhyG to a greater extent in diets with 0.29% or 0.35% phytate-bound P than in diets with 0.23% phytate-bound P (interaction, P < 0.05). At 1,000 FTU/kg, PhyG increased P digestibility and bone P more (P < 0.05) than PhyB. The PhyG increased (P < 0.01) pig growth performance, and pigs fed diets containing 0.35% or 0.29% phytate-bound P performed better (P < 0.01) than pigs fed the 0.23% phytate-bound P diets. In conclusion, the novel phytase (i.e., PhyG) is effective in increasing bone ash, mineral digestibility, and growth performance of pigs regardless of dietary phytate level.     

Modulation of jejunal mucosa-associated microbiota in relation to intestinal health and nutrient digestibility in pigs by supplementation of β-glucanase to corn–soybean meal-based diets with xylanase

This study aimed to evaluate the effects of increasing levels of β-glucanase on the modulation of jejunal mucosa-associated microbiota in relation to nutrient digestibility and intestinal health of pigs fed diets with 30% corn distiller’s dried grains with solubles and xylanase. Forty pigs at 12.4 ± 0.5 kg body weight (BW) were allotted in a randomized complete block design with initial BW and sex as blocks. Dietary treatments consisted of a basal diet with xylanase (1,500 endo-pentosanase units [EPU]/kg) and increasing levels of β-glucanase (0, 200, 400, and 600 U/kg) meeting nutrient requirements and fed to pigs for 21 d. Blood samples were collected on day 19. On day 21, all pigs were euthanized to collect intestinal tissues and digesta. Tumor necrosis factor-alpha, interleukin (IL)-6, and malondialdehyde were measured in the plasma and mid-jejunal mucosa. Viscosity was determined using digesta from the distal jejunum. Ileal and rectal digesta were evaluated to determine apparent ileal digestibility (AID) and apparent total tract digestibility (ATTD) of nutrients. Mucosa samples from the mid-jejunum were utilized for microbiota sequencing. Data were analyzed using the MIXED procedure on SAS 9.4. Overall, increasing dietary β-glucanase tended to increase (linear; P = 0.077) the average daily gain of pigs. Increasing dietary β-glucanase affected (quadratic; P < 0.05) the relative abundance of Bacteroidetes, reduced (linear; P < 0.05) Helicobacter rappini, and increased (linear, P < 0.05) Faecalibacterium prausnitzii. β-Glucanase supplementation (0 vs. others) tended to increase (P = 0.096) the AID of crude protein in the diet, whereas increasing dietary β-glucanase tended to increase (linear; P = 0.097) the ATTD of gross energy in the diet and increased (linear; P < 0.05) the concentration of IL-6 in the plasma of pigs. In conclusion, increasing β-glucanase up to 600 U/kg feed in a diet containing xylanase (1,500 EPU/kg) modulated mucosa-associated microbiota by increasing the relative abundance of beneficial bacteria and reducing potentially harmful bacteria. Furthermore, increasing β-glucanase up to 600 U/kg feed in a diet containing xylanase (1,500 EPU/kg feed) enhanced the status of the intestinal environment and nutrient utilization, as well as reduced systemic inflammation of pigs, collectively resulting in moderate improvement of growth performance. Supplementing β-glucanase at a range of 312 to 410 U/kg with xylanase at 1,500 EPU/kg feed showed the most benefit on jejunal mucosa-associated microbiota and reduced systemic inflammation of pigs.