Effects of a novel bacterial phytase expressed in Aspergillus Oryzae on digestibility of calcium and phosphorus in diets fed to weanling or growing pigs

In 2 experiments, 48 weanling (initial BW: 13.5 ± 2.4 kg, Exp. 1) and 24 growing pigs (initial BW: 36.2 ± 4.0 kg, Exp. 2) were used to determine effects of a novel bacterial 6-phytase expressed in Aspergillus oryzae on the apparent total tract digestibility (ATTD) of phosphorus and calcium in corn-soybean meal diets fed to weanling and growing pigs. In Exp. 1 and 2, pigs were randomly allotted to 6 dietary treatments using a randomized complete block design and a balanced 2 period changeover design, respectively. In both experiments, 6 diets were formulated. The positive control diet was a corn-soybean meal diet with added inorganic phosphorus (Exp. 1: 0.42 and 0.86% standardized total tract digestible phosphorus and total calcium, respectively; Exp. 2: 0.32 and 0.79% standardized total tract digestible phosphorus and total calcium, respectively). A negative control diet and 4 diets with the novel phytase (Ronozyme HiPhos, DSM Nutritional Products Inc., Parsippany, NJ) added to the negative control diet at levels of 500, 1,000, 2,000, and 4,000 phytase units (FYT)/kg were also formulated. In Exp. 1, the ATTD of phosphorus was greater (P < 0.01) for the positive control diet (60.5%) than for the negative control diet (40.5%), but increased (linear and quadratic, P < 0.01) as phytase was added to the negative control diet (40.5% vs. 61.6%, 65.1%, 68.7%, and 68.0%). The breakpoint for the ATTD of phosphorus (68.4%) was reached at a phytase inclusion level of 1,016 FYT/kg. In Exp. 2, the ATTD of phosphorus was greater (P < 0.01) for the positive control diet (59.4%) than for the negative control diet (39.8%) and increased (linear and quadratic, P < 0.01) as phytase was added to the negative control diet (39.8% vs. 58.1%, 65.4%, 69.1%, and 72.8%). The breakpoint for the ATTD of phosphorus (69.1%) was reached at a phytase inclusion level of 801 FYT/kg. In conclusion, the novel bacterial 6-phytase improved the ATTD of phosphorus and calcium in both weanling and growing pigs. The optimum level of inclusion for this phytase is 800 to 1,000 FYT/kg of complete feed to maximize ATTD of phosphorus and calcium in weanling and growing pigs.     

Pharmacokinetics and pharmacodynamics of chlorpyrifos in male and female cattle after topical administration

The aim of this work was to study the pharmacokinetic behaviour and the inhibitory effect on acetylcholinesterase and butyrylcholinesterase activities of chlorpyrifos in male and female cattle after pour-on administration. Determination of cholinesterase activity in plasma and erythrocyte was carried out according to Ellman kinetic method. The mean baseline activities were 9338.39 ± 1331.61 and 13220.69 ± 2274.18 to acetylcholinesterase and 624.65 ± 39.32 and 641.68 ± 88.08 IU/L to butyrylcholinesterase in females and males, respectively. Acetylcholinesterase was the predominant form of cholinesterase analyzed, with low levels of butyrylcholinesterase. The basal acetylcholinesterase activities of the bulls were significantly greater than those of cows. The inhibitory effect of topical chlorpyrifos administration was lower on butyrylcholinesterase than on acetylcholinesterase. Chlorpyrifos peak plasma concentration (male:10.920 ± 4.18; female:12.12 ± 3.88 μg/L) were reached at 11.92 ± 9.19 and 8.17 ± 7.67 h in male and female, respectively. The values of area under curve were 185.96 ± 168.45 and 278.89 ± 270.00 μg·h/L and mean residence time were 13.95 ± 8.10 and 14.90 ± 9.80 h in male and female, respectively.     

Effects of dietary iodine value product on growth performance and carcass fat quality of finishing pigs

A total of 120 barrows (initial BW = 47.9 ± 3.6 kg; PIC 1050) were used in an 83-d study to determine the effects of dietary iodine value (IV) product (IVP) on growth performance and fat quality. Pigs were blocked by BW and randomly allotted to 1 of 6 treatments with 2 pigs per pen and 10 pens per treatment. Dietary treatments were fed in 3 phases and formulated to 3 IVP concentrations (low, medium, and high) in each phase. Treatments were 1) corn-soybean meal control diet with no added fat (low IVP), 2) corn-extruded expelled soybean meal (EESM) diet with no added fat (medium IVP), 3) corn-soybean meal diet with 15% distillers dried grains with solubles and choice white grease (DDGS + CWG; medium IVP), 4) corn-soybean meal diet with low CWG (medium IVP), 5) corn-EESM diet with 15% DDGS (high IVP), and 6) corn-soybean meal diet with high CWG (high IVP). On d 83, pigs were slaughtered and backfat and jowl fat samples were collected and analyzed. The calculated and analyzed dietary IVP values were highly correlated (r(2) = 0.86, P < 0.01). Pigs fed the control diet, EESM, or high CWG had greater (P < 0.05) ADG than pigs fed EESM + DDGS. Pigs fed the control diet had greater (P < 0.05) ADFI than pigs fed all other diets. Pigs fed EESM + DDGS and high CWG had improved (P < 0.05) G:F compared with pigs fed the control diet or DDGS + CWG. Pigs fed diets with DDGS had greater (P < 0.05) backfat and jowl fat IV, C18:2n-6, and PUFA and less SFA than pigs fed all other treatments. Pigs fed EESM had greater (P < 0.05) backfat and jowl fat IV, C18:2n-6, and PUFA than pigs fed the control diet, low CWG, or high CWG. Pigs fed low CWG or high CWG had greater (P < 0.05) jowl fat IV than control pigs. Feeding ingredients high in unsaturated fatty acids, such as DDGS and EESM, had a greater impact on fat IV than CWG, even when diet IVP was similar. Therefore, IVP was a poor predictor of carcass fat IV in pigs fed diets with different fat sources and amounts of unsaturated fats formulated with similar IVP. Dietary C18:2n-6 content was a better predictor of carcass fat IV than diet IVP.     

仔猪教槽(一):不同教槽持续时间对窝采食仔猪比例及仔猪断奶前生长性能的影响

本研究共选用54头PIC 1050系母猪及其所产仔猪,以研究不同的教槽持续时间对教槽窝的仔猪教槽料采食量和断奶前生长性能的影响.试验进行时根据胎次和分娩日期将母猪分成2组,并利用随机化完全区组设计法将它们分成3个处理.试验仔猪从出生后第7、14和18天开始教槽,持续时间依次为13、6和2 d.利用带有送料斗的旋转式教槽料饲喂器给仔猪供应添加了氧化铬的教槽日粮(含1 585大卡代谢能/lb、1.56%真回肠可消化赖氨酸),直至断奶时(20日龄)结束.教槽期间仔猪实行自由采食,自由饮水.母猪在整个哺乳期采取自由采食,哺乳期日粮含1 586大卡代谢能/lb和0.97%真回肠可消化赖氨酸.仔猪在出生当日、出生后第7、14、18和20天进行个体称重,以计算总增重和日增重,记录并计算每窝仔猪的每日教槽料采食量.用无菌棉拭分别在仔猪出生后第14、18和20天(第一处理组)、或第18和20天(第二处理组)、或第20天(第三处理组)每天两次对所有仔猪采集粪样.在采样日的任一天中,凡仔猪粪便有一次呈绿色,则该仔猪就被认定为"采食仔猪".总体而言,采用不同教槽持续时间的试验仔猪,在断奶体重(P<0.61)、总增重(P<0.38)和日增重(P<0.38)上无显著差异.教槽持续13 d和6 d的仔猪其每窝教槽料总采食量高于教槽持续2 d的每窝仔猪教槽料采食量(P<0.0001).教槽13 d和6 d的仔猪在窝教槽料采食量上无显著差异(P<0.69).教槽持续13 d的仔猪在每窝"采食仔猪"比例上比教槽持续6 d和2 d的多10%(80%比70%;P<0.03);教槽6 d和2 d的仔猪在窝采食仔猪百分比上无显著差异(P<0.98).总之.较长的教槽持续时间并不会影响仔猪断奶前增重和断奶体重,但的确会提高整窝仔猪中的采食仔猪数;然而,在断奶前仅教槽持续2 d的仔猪窝中具有相时较高的采食仔猪比例(70%).     

仔猪教槽(二):不同设计类型的教槽料饲喂器和采食便利性对仔猪采食教槽料和窝生产性能的影响

本试验的目的是测定不同设计类型的教槽料饲喂器和较高的采食便利性对仔猪教槽料采食量及其断奶前生产性能的影响.试验选用54头PIC 1050系母猪及其所产仔猪,根据胎龄和分娩日期将试验母猪分成两批,再根据随机完全区组设计将每批试验母猪分入三个试验处理组中.处理1组为对照组,仔猪使用料斗型旋转式饲喂器;处理2组仔猪使用非料斗型旋转式饲喂器;处理3组仔猪使用长条式饲喂器.试验仔猪从分娩后第18天至断奶(第21天)进行自由采食教槽料,日粮含代谢能1 585kcal/lb、真回肠可消化赖氨酸(TID Lys)1.56%,并添加1.0%的三氧化二铬.母猪在整个哺乳期自由采食单一日粮(ME:1 586kcal/lb,TID Lys:0.97%).仔猪在出生后第0(出生当日)、18和21天(断奶时)进行个体称重,以计算总增重和日增重.计算饲喂器内饲料消耗量,并以此作为窝教槽料采食量.在断奶前3～12h,用无菌棉签对所有处理组的仔猪采集两次粪便样本.在两次取样中,仔猪粪便颜色至少有一次为绿色时,该仔猪就被认为采食教槽料仔猪(简称采食仔猪).结果表明,使用不同设计类型的饲喂器进行饲喂的仔猪,断奶时在个体重(P<0.18)和窝重(P<0.51)上均没有显著差异,在个体和窝的总增重(P<0.20)及日增重(P<0.31)上也很接近.采用非料斗型旋转式饲喂器或长条式饲喂器饲喂的仔猪,所消耗的总教槽料比使用料斗型旋转式饲喂器饲喂的仔猪多2.7倍(P<0.0001).对于料斗型旋转式、非料斗型旋转式和长条式饲喂器饲喂的仔猪,每12h平均饲喂频率分别是1、2.3和4.2次.饲喂器设计类型对饲喂教槽料仔猪中采食仔猪的比例有显著影响(P<0.0001).在使用料斗型旋转式、非料斗型旋转式和长条式饲喂器的仔猪中,采食仔猪分别占69%、47%和42%.总之,在饲喂教槽料的仔猪中,采食仔猪的比例会受非日粮因素的影响,例如饲喂器设计类型.     

Pharmacokinetic behavior and pharmacokinetic/pharmacodynamic integration of marbofloxacin after subcutaneous administration in goats

The pharmacokinetic behavior of marbofloxacin was studied in goats after single-dose subcutaneous (SC) administration of 2mg/kg bodyweight. Drug concentration in plasma was determined by high performance liquid chromatography and the data obtained were subjected to non-compartmental kinetic analysis. Marbofloxacin peak plasma concentration (C(max)=1.77+/-0.24microg/mL) was reached 1.25+/-0.50h (T(max)) after SC administration. The elimination half-life (t(1/2beta)) and area under curve (AUC) were 5.74+/-1.21h and 8.15 vs 2.33microg h/mL, respectively. Taking into account the values obtained for the efficacy indices, it was concluded that a SC dose of 2mg/kg/24h of marbofloxacin could be adequate to treat infections caused by high susceptible bacteria like Escherichia coli or Salmonella spp.     

Pharmacokinetic behaviour of enrofloxacin in greater rheas following a single-dose intramuscular administration

The pharmacokinetic behaviour of enrofloxacin in greater rheas was investigated after intramuscular (IM) administration of 15 mg/kg. Plasma concentrations of enrofloxacin and its active metabolite, ciprofloxacin, were determined by high performance liquid chromatography. Enrofloxacin peak plasma concentration (C(max)=3.30+/-0.90 microg/mL) was reached at 24.17+/-9.17 min. The terminal half-life (t(1/2lambda)) and area under the curve (AUC) were 2.85+/-0.54 h and 4.18+/-0.69 microg h/mL, respectively. The AUC and C(max) for ciprofloxacin were 0.25+/-0.06 microg/mL and 0.66+/-0.16 microg h/mL, respectively. Taking into account the values obtained for the efficacy indices, an IM dose of 15 mg/kg of enrofloxacin would appear to be adequate for treating infections caused by highly susceptible bacteria (MIC(90)<0.03 microg/mL) in greater rheas.     

Amino acid digestibility and energy content of deoiled (solvent-extracted) corn distillers dried grains with solubles for swine and effects on growth performance and carcass characteristics

A study with 3 experiments was conducted to determine the AA digestibility and energy concentration of deoiled (solvent-extracted) corn distillers dried grains with solubles (dDGS) and to evaluate its effect on nursery pig growth performance, finishing pig growth performance, and carcass traits. In Exp. 1, a total of 5 growing barrows (initial BW = 30.8 kg) were fitted with a T-cannula in the distal ileum and allotted to 1 of 2 treatments: 1) a diet with dDGS as the sole protein source, or 2) a N-free diet for determining basal endogenous AA losses in a crossover design at 68.0 kg of BW. Apparent and standardized (SID) ileal digestibility of AA and energy concentration of dDGS were determined. In Exp. 2, a total of 210 pigs (initial BW = 9.9 kg) were used in a 28-d experiment to evaluate the effect of dDGS on nursery pig performance. Pigs were allotted to 5 dietary treatments (0, 5, 10, 20, or 30% dDGS) formulated to contain equal ME (increased added fat with increasing dDGS) and SID Lys concentrations based on the values obtained from Exp. 1. In Exp. 3, a total of 1,215 pigs (initial BW = 29.6 kg) were used in a 99-d experiment to determine the effect of dDGS on growth and carcass characteristics of finishing pigs. Pigs were allotted to dietary treatments similar to those used in Exp. 2 and were fed in 4 phases. The analyzed chemical composition of dDGS in Exp. 1 was 35.6% CP, 5.29% ash, 4.6% fat, 18.4% ADF, and 39.5% NDF on a DM basis. Apparent ileal digestibility values of Lys, Met, and Thr in dDGS were 47.2, 79.4, and 64.1%, respectively, and SID values were 50.4, 80.4, and 68.9%, respectively. The determined GE and DE and the calculated ME and NE values of dDGS were 5,098, 3,100, 2,858, and 2,045 kcal/kg of DM, respectively. In Exp. 2, nursery pig ADG, ADFI, and G:F were similar among treatments. In Exp. 3, increasing dDGS reduced (linear; P < 0.01) ADG and ADFI but tended to improve (linear; P = 0.07) G:F. Carcass weight and yield were reduced (linear; P < 0.01), loin depth tended to decrease (linear; P = 0.09), and carcass fat iodine values increased (linear; P < 0.01) as dDGS increased. No difference was observed in backfat, percentage of lean, or fat-free lean index among treatments. In conclusion, dDGS had greater CP and AA but less energy content than traditional distillers dried grains with solubles. In addition, when dietary fat was added to diets to offset the reduced ME content, feeding up to 30% dDGS did not affect the growth performance of nursery pigs but did negatively affect the ADG, ADFI, and carcass fat quality of finishing pigs.     

Effects of age on the pharmacokinetics of single dose sulfamethazine after intravenous administration in cattle

Sulphonamides are still being used widely, influenced by the low cost and the efficacy against many common bacterial infections, since they present a broad spectrum of activity. The aim of this study was to determine the effect of age on the pharmacokinetic/pharmacodynamics (PK/PD) integration of intravenous sulfamethazine (60 mg/kgbw) in cattle, and the possible therapeutic outcomes. Six healthy female calves, at the age of one, three, seven and fifteen weeks were used. Normality analysis was assessed with the Shapiro-Wilk test. Non-parametric tests for paired data were used. Plasma concentrations were quantified using HPLC/uv. Differences were found between one-three-weeks-old calves and seven-fifteen-weeks-old calves, in pharmacokinetic parameters (clearance, area under the concentration-time curve and elimination half-life) and in the PK/PD integration. The ratios obtained in PK/PD integration (T>MIC, WAUC) confirm that it is necessary to apply twice the dose of sulfamethazine in ≥ 7 weeks-old cattle to reach a satisfactory dosage regimen (MIC ≥ 32 μg/mL).