True Digestibility of Phosphorus in Different Resources of Feed Ingredients in Growing Pigs

Wu, X.,Ruan, Z.,Zhang, Y.G.,Hou, Y.Q.,Yin, Y.L.,Li, T.J.,Huang, R.L.,Chu, W.Y.,Kong, X.F.,Gao, B.,Chen, L.X. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.1

To determine the true digestible phosphorus (TDP) requirement of growing pigs, two experiments were designed with the experimental diets containing five true digestible P levels (0.16%, 0.20%, 0.23%, 0.26% and 0.39%) and the ratio of total calcium to true digestible P (TDP) kept at 2:1. In Experiment 1, five barrows (Duroc${\times}$Landrace${\times}$Yorkshire) with an average initial body weight of 27.9 kg were used in a $5{\times}5$ Latin-square design to evaluate the effect of different dietary P levels on the digestibility and output of P and nitrogen. In Experiment 2, sixty healthy growing pigs (Duroc${\times}$Landrace${\times}$Yorkshire) with an average body weight (BW) of 21.4 kg were assigned randomly to one of the five dietary treatments (12 pigs/diet), and were used to determine the true digestible phosphorus (TDP) requirement of growing pigs on the basis of growth performance and serum biochemical indices. The results indicated that the true digestibility of P increased (p<0.05) linearly with increasing dietary TDP level below 0.26%. The true P digestibility was highest (56.6%) when dietary TDP was 0.34%. Expressed as g/kg dry matter intake (DMI), fecal P output increased (p<0.05) linearly with increasing P input. On the basis of g/kg fecal dry matter (DM), fecal P output was lowest for Diet 4 and highest (p<0.05) for Diet 5. The apparent digestibility of crude protein (CP) did not differ (p>0.05) among the five diets, with the average nitrogen output of 12.14 g/d and nitrogen retention of 66% to 74% (p>0.05), which suggested that there was no interaction between dietary P and CP protein levels. During the 28-d experimental period of Experiment 2, the average daily gain (ADG) of pigs was affected by dietary TDP levels as described by Eq. (1): $y=-809,532x^4+788,079x^3-276,250x^2+42,114x-1,759$; ($R^2=0.99$; p<0.01; y = ADG, g/d; x = dietary TDP, %), F/G for pigs by Eq. (2): $y=3,651.1x^4-3,480.4x^3+1,183.8x^2-172.5x+10.9$ ($R^2=0.99$; p<0.01; y = F/G; x = dietary TDP, %), and Total P concentrations in serum by Eq. (3): $y=-3,311.7x^4+3,342.7x^3-1,224.6x^2+195.6x-8.7$ (R2 = 0.99; p<0.01; y = total serum P concentration and x = dietary TDP, %). The highest ADG (782 g/d), the lowest F/G (1.07) and the highest total serum P concentration (3.1 mmol/L) were obtained when dietary TDP level was 0.34%. Collectively, these results indicate that the optimal TDP requirement of growing pigs is 0.34% of the diet at a total Ca to TDP ratio of 2:1.

Effect of the Transformed Lactobacillus with Phytase Gene on Pig Production Performance, Nutrient Digestibility, Gut Microbes and Serum Biochemical Indexes

Yin, Q.Q.,Chang, J.,Zuo, R.Y.,Chen, L.Y.,Chen, Q.X.,Wei, X.Y.,Guan, Q.F.,Sun, J.W.,Zheng, Q.H.,Yang, X.,Ren, G.Z. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.2

In order to improve the availability of phytase and probiotics together, a phytase gene from Aspergillus ficuum has been expressed in Lactobacillus. In this study, the transformed Lactobacillus with phytase gene was fed to pigs to determine its effect on pig production, feed conversion and gut microbes. Forty eight, 60-day-old, castrated pigs (Duroc${\times}$Landrace${\times}$Pietrain) were assigned to 6 groups, 8 pigs for each group. Group 1 was the control, group 2 was added with chlortetracycline (500 mg/kg), group 3 was added with the transformed Lactobacillus (500 mg/kg) with 20% (w/w) of calcium monohydrogen phosphate (CMP, $CaHPO_{4}$) removed, group 4 was added with the natural Lactobacillus (500 mg/kg) with 20% (w/w) of CMP removed, group 5 was added with the transformed Lactobacillus (500 mg/kg) with 40% (w/w) of CMP removed, group 6 was added with phytase (500 mg/kg) with 40% (w/w) of CMP removed. The results showed: i) the average daily gain (ADG) was improved in groups 2, 3 and 4 (p<0.05); ii) the diarrhea rates in the groups added with Lactobacillus were lower than in the other groups (p<0.05), in which the transformed Lactobacillus had more effect on reducing digestive disease; iii) the transformed Lactobacillus was most effective in improving the digestibilities of crude protein (CP), calcium (Ca), phosphorus (P), compared with the other groups (p<0.05); iv) Lactobacillus could increase lactic acid bacterium number and ammonia concentrations, and decrease pH values and E. coli number in pig feces (p<0.05); v) the phytase activity in the feces of pigs fed with the transformed Lactobacillus was 133.32 U/g, which was higher than in group 4 (9.58 U/g, p<0.05), and was almost the same as group 6 (135.94 U/g); vi) the transformed Lactobacillus could increase serum concentrations of IgA, triglyceride, and glutamic oxaloacetic transaminase activity (p<0.05), and had no significant effect on other serum indexes (p>0.05).

Research on force and temperature characteristics of novel point grinding wheels

G. Q. Yin,Y. D. Gong,Y. W. Li,J. Cheng 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.8

We propose a novel point grinding wheel (NPGW) with coarse grinding zone angle θ. According to earlier studies, this type of grinding wheel has high grinding efficiency, long service life, and generates very little surface roughness. The contact zone between the grinding wheel and workpiece is modified by the addition of the NPGW with the coarse grinding zone angle θ and the inclined angle α of point grinding process, and as a result, grinding force and grinding zone temperature are also altered. The grinding force theoretical model of NPGW was established and the grinding zone temperature was simulated by the finite element method, based on the theory of grinding heat generation and distribution and triangular heat source distribution model. At the same time, seven pieces of NPGW with different angles θ used for grinding experiments were fabricated. The theoretical model of grinding force and the simulation of grinding temperature coincided with experimental results. Therefore, the grinding force theoretical model and the grinding temperature simulation provide an auxiliary and predictive method for the actual process. Moreover, the influence of parameters on grinding force and grinding zone temperature can be obtained, and the results indicate that the NPGW and point grinding process can reduce grinding force and grinding zone temperature. Finally, plastic deformation is attributed to the production of compressive stress and grinding heat is attributed to the production of tensile stress. Therefore, the residual stress is influenced by the grinding force and the grinding temperature coupled. The residual stress of workpiece surface and subsurface was studied. In conclusion, the NPGW and point grinding process can reduce residual stress of workpiece surface and subsurface, in the case of tensile and compressive stress.

Effect of Galacto-mannan-oligosaccharides or Chitosan Supplementation on Cytoimmunity and Humoral Immunity in Early-weaned Piglets

Yin, Y.-L.,Tang, Z.R.,Sun, Z.H.,Liu, Z.Q.,Li, T.J.,Huang, R.L.,Ruan, Z.,Deng, Z.Y.,Gao, B.,Chen, L.X.,Wu, G.Y.,Kim, S.W. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.5

Immunomodulatory feed additives might offer alternatives to antimicrobial growth promoters in pig production. This experiment was designed to determine the effects of dietary galacto-mannan-oligosaccharide (GMOS) and chitosan oligosaccharide (COS) supplementation on the immune response in early-weaned piglets. Forty 15-day-old piglets (Duroc$\times$Landrace$\times$Yorkshire) with an average live body weight of $5.6{\pm}0.51kg$ were weaned and randomly assigned to 4 treatment groups that were fed maize-soybean meal diets containing either basal, 110 mg/kg of lincomycin, 250 mg/kg of COS or 0.2% GMOS, respectively, over a 2-week period. Another six piglets of the same age were sacrificed on the same day at the beginning of the study for sampling, in order to obtain baseline values. Interleukin (IL)-1${\beta}$gene expression in peripheral blood monocytes, jejunal mucosa and lymph nodes, as well as serum levels of IL-1${\beta}$ IL-2 and IL-6, IgA, IgG, and IgM, were evaluated for 5 pigs from each group at 15 and 28 days of age. The results indicate that weaning stress resulted in decreases in serum antibody and cytokine levels. Dietary supplementation with GMOS or COS enhanced (p<0.05) IL-1${\beta}$gene expression in jejunal mucosa and lymph nodes, as well as serum levels of IL-1${\beta}$ IL-2, IL-6, IgA, IgG and IgM compared to supplementation with lincomycin. These findings suggest that GMOS or COS may enhance the cell-mediated immune response in early-weaned piglets by modulating the production of cytokines and antibodies, which shows that GMOS or COS have different effects than the antibiotic on animal growth and health.

Optimal Conditions for Lactobacillus parafarraginis ZH1 Producing Hexadecanoic Acid

J. G. Zhang,Q. H. Liu,G. L. Yin 한국초지조사료학회 2016 한국초지조사료학회 학술대회논문집 Vol.2016 No.08

Research on simulation and experiment for surface topography machined by a novel point grinding wheel

Y. D. Gong,G. Q. Yin,X. L. Wen,M. Han,J. B. Yan,J. Cheng 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.10

Grains motion path will be changed in the point grinding process due to the existence of variable angle α. To verify the difference betweenpoint grinding and traditional grinding, the moving relationship and coordinate transformation between grinding wheel and workpieceare used to put the grain movement function equivalent to parabola, then point grinding cutting path is concluded. Based on grainsdistribution on the grinding wheel surface, the 3D geometry simulation topography of workpiece is obtained by extending the effectiveinterference trails along the axial direction. Furthermore, a vitrified bond CBN wheel with a coarse grinding area angle θ is proposed andthe principle of design and preparation of these novel grinding wheels are studied. The typical processing parameters are chosen to grindQT700 ladder shaft; the simulation results are verified by using the VHX-1000E microscope and the non-contact 3D surface profilometerto observe the workpiece surface topography and measure the surface roughness. The results indicated that the simulation microstructurescoincide well with the experimental measurements and the values of simulation roughness are 0.5 times of experiments. So, the geometricsimulation model provided an auxiliary and prediction method for the actual processing topography analysis. In addition, grindingwheels with different θ are used to grind ladder shafts with a series of grinding parameters. The influence trend of inclining angle α, cuttingdepth ap, axial feeding speed vf and grinding wheel speed vs on surface roughness is obtained. It is concluded that the values ofworkpiece surface roughness using novel grinding wheel are less than using the traditional grinding wheel under the condition of thesame processing parameters.

Nitrogen-corrected True Metabolizable Energy and Amino Acid Digestibility of Chinese Corn Distillers Dried Grains with Solubles in Adult Cecectomized Roosters

Li, F.,Liu, Y.,Yin, R.Q.,Yang, X.J.,Yao, J.H.,Sun, F.F.,Li, G.J.,Liu, Y.R.,Sun, Y.J. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.6

This study was conducted to evaluate chemical composition, nitrogen-corrected true metabolizable energy (TMEn) and true amino acids digestibility of corn distillers dried grains with solubles (DDGS) produced in China. Twenty five sources of corn DDGS was collected from 8 provinces of China. A precision-fed rooster assay was used to determine TMEn and amino acids digestibility with 35 adult cecectomized roosters, in which each DDGS sample was tube fed (30 g). The average content of ash, crude protein, total amino acid, ether extract, crude fiber and neutral detergent fiber were 4.81, 27.91, 22.51, 15.22, 6.35 and 37.58%, respectively. TMEn of DDGS ranged from 1,779 to 3,071 kcal/kg and averaged 2,517 kcal/kg. Coefficient of variation for non-amino acid crude protein, ether extract, crude fiber and TMEn were 55.0, 15.7, 15.9 and 17.1%, respectively. The average true amino acid digestibility was 77.32%. Stepwise regression analysis obtained the following equation: TMEn, kcal/kg = -2,995.6+0.88${\times}$gross energy+$49.63{\times}a^*$ (BIC = 248.8; RMSE = 190.8; p<0.01). Removing gross energy from the model obtained the following equation: TMEn, kcal/kg = 57.88${\times}$ether extracts+$87.62{\times}a^*$ (BIC = 254.3, RMSE = 223.5; p<0.01). No correlation was found between color scores and lysine true digestibility (p>0.05). These results suggest that corn DDGS produced in China has a large variation in chemical composition, and gross energy and $a^*$ value can be used to generate TMEn predict equation.

Effects of a Stair-step Growth Pattern on Improvements in Meat Quality and Growth in Hanwoo Steers

Li, Z.H.,Lee, H.G.,Xu, C.X.,Hong, Z.S.,Jin, Y.C.,Yin, J.L.,Zhang, Q.K.,Piao, D.C.,Yang, U.M.,Choi, Y.J. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.11

The present study was conducted to examine the effect of a stair-stepped feed intake pattern on growth, feed efficiency, and meat quality of Hanwoo steers. Twenty-seven 11-month-old Hanwoo steers were randomly divided into three groups. The control group was fed according to the Korean steer feeding program, and the other two groups were fed according to an alternated feeding schedule of 3-2-4-2 months. During the first three months of the experiment, treatment group 1 (T1) and treatment group 2 (T2) were fed 20% and 30% less than the control group, respectively. For the following two months, the T1 group was fed 20% more than the control group while the T2 group was fed 20% less than the control group. In the third step, T1 and T2 groups were fed 20% and 10% less, respectively, than the control group for four months. In the last two months, T1 and T2 groups were fed 20% more than the control group. After the stair-step feeding trial, steers were fed concentrated feed ad libitum for five months. The altered feed intake pattern did not affect daily body weight gain. However, daily feed intake tended to decrease and growth efficiency tended to increase in the two treatment groups compared to the control group. Altered feed intake also affected blood metabolite levels. The serum glucose and BUN level of the T1 group increased in the first re-fed period compared to the T2 and control groups. The serum cholesterol level of the T2 group decreased in the first restricted-re-fed growth period compared to the T1 and control groups. The serum NEFA levels of the two treatment groups increased from the first restricted period compared to the controls. The serum insulin level of the T2 group increased in the last period compared to the T1 and control groups. Regarding meat yield index, the control group was significantly higher than the T2 group (p<0.05). Regarding meat yield grade, the carcass back fat thickness of the T2 group was significantly higher than the control group (p<0.05). In marbling score, the T1 group was the highest (4.9), followed by the control group (4.1) and the T2 group (4.0). These results indicate that using a stair-stepped growth pattern (T1) can contribute to improvements in growth efficiency and muscle marbling.

Experimental study on fabrication and evaluation of a micro-scale shaft grinding tool

Y. D. Gong,X. L. Wen,J. Cheng,G. Q. Yin,C. Wang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.3

This paper presents a micro-grinding experiment on AISI 1020 steel and Ti-6Al-4V to study micro-grinding principle and the changerule of the force and surface with different grinding parameters. A novel micro shaft grinding tool is fabricated by cold sprayed withCBN grains, the manufacturing is carried out on a desktop micro machine developed by NEU. Influences caused by particle size on surfacequality has been discussed, it has been tested that low surface roughness could be achieved on 3000 particle size of micro shaftgrinding tool, the roughness of AISI 1020 steel accomplished in the experiment is about 0.086 μm. Measured micro-grinding force of Ti-6Al-4V decreases with the increasing spindle speed and the decreasing cutting depth. The surface roughness decreases with the increasingspindle speed and the decreasing feed rate. The minimum surface roughness is 325 nm with the spindle speed of 48000 r/min and thefeed rate of 20 μm/s.