日粮中不同蛋氨酸、苏氨酸水平对断奶仔猪有关血液生化指标的影响

试验采用早期断奶仔猪 72头 ,按 2× 3因素水平设计 ,即 2个蛋氨酸水平 (0 .2 9% ,0 .39% )和 3个苏氨酸水平 (0 .6 0 % ,0 .6 8%和 0 .76 % )分为 6种日粮处理。基础日粮为玉米 -小麦 -豆粕 -花生粕型日粮 ,试验期为 2 2d。试验第 2 1天 ,各重复选取 1头仔猪采前腔静脉血 ,分析血清尿素氮 (BUN)、总蛋白 (TP)、白蛋白 (ALB)的浓度及游离氨基酸质量浓度。结果表明 ,日粮中不同的苏氨酸水平影响血清BUN、TP的浓度 (P <0 .0 5 )及血清ALB的浓度 (P<0 .0 1)。血清BUN浓度与日粮苏氨酸水平呈显著负相关 ,随着日粮苏氨酸水平的提高 ,血清BUN浓度直线降低(P <0 .0 1)。随着日粮中苏氨酸水平和蛋氨酸水平的提高 ,血清中游离苏氨酸与蛋氨酸水平分别呈直线上升 (P<0 .0 1)。     

安普霉素对仔猪的促生长作用研究

采用单因子试验设计 ,72头 2 8日龄大长北三元杂交断奶仔猪随机分为 3组 ,分别饲喂含有 0 ,2 0 ,90mg/kg安普霉素的日粮。试验期为 4周 ,检测仔猪日增重、日采食量及饲料转化率等指标。研究结果表明 :在饲料中添加 90mg/kg安普霉素能明显降低仔猪腹泻发生率 ,对仔猪具有显著促生长作用。可提高断奶后 0～ 4周内仔猪日增重 19.1%～ 2 4 .6 % (P <0 .0 5 ) ,改善饲料转化率7.7%～ 8.5 % (P <0 .0 5 ) ,并可提高日采食量 8.4 %～ 13.1%。尤其在试验前期 (断奶后 0～ 2周 )作用更明显     

有机铬对母猪繁殖性能及其仔猪生长的影响

选择胎次、体重及体况相近的长×约二元杂交经产母猪 14头 ,随机分成对照组和试验组两组进行饲养试验。从配种日起 ,至仔猪断奶后母猪下一次发情为止。对照组饲喂实用饲粮 (不添加有机铬制剂 ,含铬 0 μg/kg) ;试验组饲喂试验饲粮 (实用饲粮中添加有机铬制剂 ,含铬2 0 0 μg/kg)。研究结果表明 ,与对照组比较 ,试验组母猪繁殖性能有所改善 ,窝产活仔数增加4.0 7% (P >0 .0 5 ) ,初生活仔猪窝重增加 7.48% (P >0 .0 5 ) ;2 1日龄窝活仔数增加 10 .0 0 %(P >0 .0 5 ) ,窝重增加 2 2 .39% (P <0 .0 5 ) ,个体重增加 11.33% (P <0 .0 5 ) ;2 9日龄断奶窝仔猪数增加 10 .30 % ,断奶窝重增加 12 .5 8%。     

蛋氨酸对宫内发育迟缓断奶仔猪血浆生化指标和肠道消化吸收功能的影响

目的:研究蛋氨酸对宫内发育迟缓(IUGR)断奶仔猪血浆生化指标和肠道消化吸收功能的调节作用。方法:所有仔猪于21 d龄断奶,30头正常出生体重(NBW)断奶仔猪饲喂基础日粮(NBW-CON组),60头IUGR断奶仔猪随机分成两个处理组,分别饲喂基础日粮(IUGR-CON组)和添加0.12%蛋氨酸的实验日粮(IUGR-MET组),每个处理组6个重复,每个重复5头猪,实验期为28 d。结果:与NBW-CON断奶仔猪相比,IUGR-CON断奶仔猪血浆尿素氮含量显著升高(p0.05),血浆总蛋白和D-木糖含量显著降低(p0.05)。IUGR-CON断奶仔猪粗蛋白和总能表观消化率、空肠食糜胰蛋白酶活性、黏膜碱性磷酸酶和Na+-K+-ATP酶活性均显著降低(p0.05)。与IUGR-CON断奶仔猪相比,IUGR-MET断奶仔猪血浆尿素氮含量显著降低(p0.05),血浆D-木糖含量显著升高(p0.05)。日粮添加0.12%蛋氨酸显著缓解IUGR介导断奶仔猪粗蛋白表观消化率、空肠食糜胰蛋白酶活性和黏膜Na+-K+-ATP酶活性降低(p0.05)。结论:日粮添加0.12%蛋氨酸可降低IUGR断奶仔猪血浆尿素氮含量,并在一定程度上缓解了IUGR对断奶仔猪肠道消化吸收功能的不良影响。     

樱桃谷肉鸭C.V.Super-MO-50日龄营养需要的研究(初报)

由于我国肉鸭饲养标准还未制定,用 C、V、Super—M 分两个阶段,各以三种营养水平进行试验。结果:0—21日龄,以 ME2830大卡/kg、CP18.5%、DCP161.5g/kg、CF5.9%、EE4.3%、Ca2.3%、P0.9%、Lys1.26%、Met0.58%、Met Cys0.88%为佳,达到体重1049.8g(800—1285)。日增重47.85g,增重1004.8g。增重1kg 耗饲料1.45kg,成活率100%,接近C.V.Farms Ltd 1985年水平。22—50日龄,虽选出以 ME2870大卡/kg、CP16.2%、DCP135g/kg、EE2.9%、Ca1.596%、P0.7%、Lys1.22%、Met0.48%、Met Cys0.77%为好,但生长速度只有C.V.Farms Ltd 的87.16%,主要原因可能是 ME、EE 和 Met 偏低,应考虑 ME3000大卡/kg、EE4%、Met0.52%的营养水平。0—50日龄到全期达到:体重2718g(2200—3250)、增重2673g。日增重52.41g。每增重1kg 耗饲料3.00kg。屠宰率88.74%,全净膛率79.72,胸肌重218.94g。胸肌率11.6%。成活率100%。试验中发现,41日龄前生长率呈直线上升,21—41日龄阶段,绝对增重最大,生长速率最高,饲料报酬最佳,N 积存率最高。42日龄后降慢持平。商品肉鸭要强化41日龄前这阶段的饲养管理和营养水平,42日龄结束饲养,使体重达2750g 上市。     

玉米赤霉烯酮饲粮添加蒙脱石对断奶仔猪脾脏和外周血免疫指标的影响

选择(28±1)日龄、平均体重为(8.84 ±0.21)kg的健康三元(斯格×长×大)杂交断奶仔猪(公母各半)18头,研究1 mg/kg玉米赤霉烯酮(zearalenone,ZEA)污染饲粮对断奶仔猪脾脏和外周血淋巴细胞增殖率和IL-2产量的影响,同时评价改性蒙脱石的脱毒效应.将试验仔猪按照体重随机分为3个处理(公母各半),仔猪采用试验笼单独饲养.试验处理为:Contr.=基础饲粮;ZEA+CZ0=基础饲粮+1 mg/kg ZEA;ZEA+ CZ4=基础饲粮+1 mg/kg ZEA+4g/kg改性蒙脱石.预饲期7d,正式期22 d.结果表明:1)与对照组相比,饲粮添加1 mg/kg ZEA显著降低断奶仔猪脾脏相对重量、外周血和脾脏淋巴细胞增殖率以及IL-2产量(P＜0.05).2)1 mg/kg的ZEA处理饲粮添加4 g/kg改性蒙脱石能够显著改善ZEA诱导的脾脏和外周血淋巴细胞增值率以及IL-2的改变(P＜0.05).结果揭示,1 mg/kg的ZEA足以影响断奶仔猪脾脏的生长发育及其细胞免疫功能,添加4 g/kg改性蒙脱石具有显著的脱毒效应,以上结果对指导动物生产和人类健康具有重要的借鉴意义.     

微生物发酵配合饲料对断奶仔猪生产性能的影响

试验选用25日龄体重相近、健康度良好的杜长大三元杂交断奶仔猪120头,随机分为3组,每组5个重复,每个重复8头猪(公母各半)。对照组为基础日粮+抗生素+酸化剂,试验1组为基础日粮+发酵剂A(1 kg/t)发酵,试验2组为基础日粮+发酵剂B(1 kg/t)发酵,旨在研究微生物发酵配合饲料对断奶仔猪生产性能的影响。结果表明,配合饲料添加微生态制剂发酵后,饲料pH值分别降低0.77和0.68(P0.01)。与对照组相比,饲喂发酵配合饲料的2个试验组仔猪采食量有提高的趋势,腹泻率有降低的趋势,料重比有增加的趋势,但差异均未达到显著水平(P0.05)。     

日粮亮氨酸水平与宫内发育迟缓对断奶仔猪肝脏抗氧化功能的影响

研究日粮亮氨酸水平与宫内发育迟缓(IUGR)对断奶仔猪肝脏抗氧化功能的影响。挑选16头正常初生重(NBW)仔猪和16头IUGR仔猪,公母各半。仔猪于14日龄断奶,采用2×2因子设计,一半NBW与IUGR断奶仔猪饲喂基础日粮,剩余断奶仔猪饲喂添加0.35%亮氨酸的实验日粮,即4个处理组,每个处理组8个重复,每个重复1头仔猪。实验期为21 d。结果表明:与NBW断奶仔猪相比,IUGR断奶仔猪肝脏总超氧化物歧化酶(T-SOD)活力显著降低,丙二醛(MDA)含量显著升高(p0.05)。IUGR断奶仔猪肝脏线粒体锰超氧化物歧化酶(Mn-SOD)活力、谷胱甘肽过氧化物酶(GSH-Px)活力、还原型谷胱甘肽(GSH)含量较NBW断奶仔猪均显著降低(p0.05)。另外,IUGR显著降低断奶仔猪肝脏核转录因子2(Nrf2)、超氧化物歧化酶1(SOD1)、超氧化物歧化酶2(SOD2)、谷胱甘肽过氧化物酶1(GPx1)mRNA表达量(p0.05)。日粮添加0.35%亮氨酸可显著降低断奶仔猪肝脏MDA含量,显著提高SOD2 mRNA表达量(p0.05)。高亮氨酸水平日粮可显著缓解IUGR介导断奶仔猪线粒体GSH含量降低与肝脏SOD2和GPx1mRNA表达下调(p0.05)。因此,日粮添加0.35%亮氨酸,可降低断奶仔猪肝脏脂质过氧化程度,一定程度缓解了IUGR对断奶仔猪肝脏抗氧化功能的不良影响。     

7种酿酒酵母培养物成分分析及对仔猪的应用效果

对市售的7种酿酒酵母培养物用国标方法或通用方法对其质量指标检测。各个样品的蛋白质质量分数为12.3%～25.1%、粗灰分1.3%～13.2%、粗纤维1.8%～12.3%、甘露聚糖(未检出～1.5%)、黄曲霉毒素B120μg/kg,赤霉烯酮20～820μg/kg,呕吐毒素50～4 700μg/kg。在断奶仔猪上进行了饲喂试验,以考察酿酒酵母培养物对仔猪生产性能的影响。选取320头28d断奶的仔猪(体重7.3～7.5kg),随机分为8组。对照组饲喂基础日粮,自由采食。酿酒酵母培养物1～7组按每个产品推荐量在基础日粮中添加酵母培养物,考察日增重、采食量和料肉比。结果有3组日增重、采食量与对照组相比有明显提高;有2组采食量与对照组相比显著提高,日增重却无明显差异。另2组各指标与对照组无明显差异。     

低聚木糖和酸化剂对断奶仔猪生产性能的影响

试验通过在仔猪日粮中添加低聚木糖和酸化剂,来研究其对早期断奶仔猪增重、料重比以及腹泻率的影响,并探讨低聚木糖与酸化剂是否具有协同作用.按体重和性别分成4个处理组:对照组(饲喂玉米-豆粕基础日粮)、低聚木糖(200 mg/kg)组、酸化剂(8 g/kg)组、合用组(添加低聚木糖(200 mg/kg)和酸化剂(8 g/kg)).结果表明,试验组平均日增重、料重比得到改善(P＜0.05),腹泻率显著下降(P＜0.01).研究认为低聚木糖和酸化剂合用可在一定程度上提高断奶仔猪的生产性能.     

Effects of methionine plus cysteine inclusion on performance and body composition of liquid-fed crossbred calves fed a commercial milk replacer and no starter feed

This experiment aimed to evaluate the effects of supplying 4 different inclusion levels of Met + Cys to crossbred liquid-fed calves on animal performance and body composition. Thirty-six Holstein-Gyr male calves were separated into 2 age groups: 16 calves, slaughtered at an age of 30 d, representing the physiological phase from 8 to 30 d, and 20 calves, slaughtered at an age of 60 d, representing the physiological phase from 30 to 60 d. At 8 d of age, the animals were randomly distributed among the experimental treatments: 4 Met + Cys inclusion levels (Met + Cys: 8.0, 8.7, 9.4, and 10.2 g/d), provided by an AA supplement added to 1.0 kg (as fed) of commercial milk replacer containing soy protein concentrate and wheat protein isolate reconstituted at 13.8% (dry matter basis). The diet was supplied without allowing leftovers and no starter feed was provided. The experimental diets were supplied without allowing orts, so that the dry matter, crude protein, and ether extract intakes were the same for all animals, independent of Met + Cys level. Total weight gain, average daily gain, gain composition, and body composition were evaluated for both age groups separately. Digestibility of organic matter, crude protein, and ether extract was lower for 8 to 30 d than for 30 to 60 d. The effect of Met + Cys levels on the digestibility of nutrients was not observed; there also was no significant interaction between physiological phase and Met + Cys levels. For the 8 to 30 d group, no responses in performance were observed according to the different Met + Cys levels, which indicates that 8.0 g/d of Met + Cys met the requirements for this physiological phase. The 30 to 60 d group responded positively to higher Met + Cys inclusion in the diet. In conclusion, an optimal Met + Cys dietary level to ensure best performance and protein gain ranges from 8.41 to 9.81 g/d.     

Optimal concentrations of lysine, methionine, and threonine in milk replacers for calves less than five weeks of age

The AA requirements of herd-replacement calves less than 5 wk old and fed milk replacers are not clearly defined and have been estimated in a limited number of studies using milk-fed calves ranging from 5 to 20 wk of age. The objective of these 4 studies was to investigate the effect of supplementing milk replacers containing 24 to 28% crude protein (CP; from milk sources) and 17% fat with Lys, Met, and Thr to estimate the optimum requirements for calves less than 5 wk of age. Holstein bull calves (initially 3 and 4 d old, 43 ± 1 kg of body weight, BW) were fed an 18% CP (as-fed) starter ad libitum and weaned at 31 to 32 d of age (28-d studies). Calves were housed in an unheated, curtain-sided nursery. In study 1, 6 milk replacer treatments were fed based on the combination of 3 CP concentrations (24, 26, and 28% CP) each with or without added Lys and Met. In studies 2 and 3, 26% CP and 2.34% Lys milk replacer treatments were fed to test the concentration of Met (0.64, 0.68, and 0.72% Met in study 2 and 0.64, 0.72, and 0.80% Met in study 3). In study 4, 26% CP, 2.34% Lys, and 0.72% Met milk replacer treatments were fed to test the concentration of Thr (1.06, 1.43, and 1.80%). There was a 17% improvement in average daily gain (ADG) in study 1 from adding Lys and Met that was maximized with 2.34% Lys. The ADG response to added Met in studies 2 (linear) and 3 (quadratic) were 13 and 7%, respectively, with a plateau at 0.72% Met. There was no ADG or efficiency response to added Thr in study 4. Formulating 17% fat, whey-based milk replacers fed at 0.68 kg/d to 26% CP, 2.34% Lys, and 0.72% Met appeared optimum based on responses of body weight gain, feed efficiency, and serum concentrations of urea nitrogen, while feeding calves more CP and essential AA did not improved ADG and efficiency. Requirements for calves less than 5 wk old, averaging 48 kg of BW, consuming 204 g of CP/d, and gaining 0.46 kg of BW/d, appeared to be met with 17 g of Lys, 0.31 Met:Lys ratio, 0.54 Met+Cys:Lys ratio, and a Thr:Lys ratio less than 0.60.     

Effect of intensified feeding of heifer calves on growth, pubertal age, calving age, milk yield, and economics

The objective of this study was to determine if increasing the energy and protein intake of heifer calves would affect growth rates, age at puberty, age at calving, and first lactation milk yield. A second objective was to perform an economic analysis of this feeding program using feed costs, number of nonproductive days, and milk yield data. Holstein heifer calves born at the Michigan State Dairy Cattle Teaching and Research Center were randomly assigned to 1 of 2 dietary treatments (n = 40/treatment) that continued from 2 d of age until weaning at 42 d of age. The conventional diet consisted of a standard milk replacer [21.5% crude protein (CP), 21.5% fat] fed at 1.2% of body weight (BW) on a dry matter basis and starter grain (19.9% CP) to attain 0.45 kg of daily gain. The intensive diet consisted of a high-protein milk replacer (30.6% CP, 16.1% fat) fed at 2.1% of BW on a dry matter basis and starter grain (24.3% CP) to achieve 0.68 kg of daily gain. Calves were gradually weaned from milk replacer by decreasing the amount offered for 5 and 12 d before weaning for the conventional and intensive diets, respectively. All calves were completely weaned at 42 d of age and kept in hutches to monitor individual starter consumption in the early postweaning period. Starting from 8 wk of age, heifers on both treatments were fed and managed similarly for the duration of the study. Body weight and skeletal measurements were taken weekly until 8 wk of age, and once every 4 wk thereafter until calving. Calves consuming the intensive diet were heavier, taller, and wider at weaning. The difference in withers height and hip width was carried over into the early post-weaning period, but a BW difference was no longer evident by 12 wk of age. Calves fed the intensive diet were younger and lighter at the onset of puberty. Heifers fed the high-energy and protein diet were 15 d younger at conception and 14 d younger at calving than heifers fed the conventional diet. Body weight after calving, daily gain during gestation, withers height at calving, body condition score at calving, calving difficulty score, and calf BW were not different. Energy-corrected, age-uncorrected 305-d milk yield was not different, averaging 9,778 kg and 10,069 kg for heifers fed the conventional and intensive diets, respectively. However, removing genetic variation in milk using parent average values as a covariate resulted in a tendency for greater milk from heifers fed the intensive diet. Preweaning costs were higher for heifers fed the intensive diet. However, total costs measured through first lactation were not different. Intensified feeding of calves can be used to decrease age at first calving without negatively affecting milk yield or economics.     

Effects of providing two forms of supplemental methionine to periparturient Holstein dairy cows on feed intake and lactational performance

Eighteen primiparous and 42 multiparous Holstein cows were blocked according to parity and expected calving date and assigned randomly to 1 of 3 dietary treatments: 1) a basal diet (negative control), 2) the basal diet plus 2-hydroxy-4-methylthio butanoic acid isopropyl ester (MetaSmart, Adisseo Inc., Antony, France), or 3) the basal diet plus rumen-protected Met (Smartamine M, Adisseo Inc., Alpharetta, GA). Treatments were initiated 21 d before expected calving and continued through 140 d postpartum. Diets were similar in ingredient and chemical composition, except for the content of Met in metabolizable protein. MetaSmart [0.35% prepartum and 0.54% postpartum in diet dry matter (DM)] and Smartamine M (0.06% prepartum and 0.10% postpartum in diet DM) were added to the basal diet in amounts needed to achieve a 3.0:1 ratio of Lys to Met in metabolizable protein. Prepartum DM intake (DMI; 13.5 kg/d), body weight (687 kg), body condition score (3.81), postpartum milk yield (42.0 kg/d), milk fat yield (1,549 g/d), milk fat content (3.66%), milk true protein yield (1,192 g/d), and milk urea N content (12.9 mg/dL) were not different among treatments. Postpartum DMI and body condition score were greater and the ratios of milk:DMI and milk N:feed N were less for cows fed the MetaSmart diet than for cows fed the control and Smartamine M diets. Milk protein content was greater for the Smartamine M (2.87%) and MetaSmart (2.81%) treatments than for the control treatment (2.72%). Concentrations of Met and Met + Cys in total plasma AA were different among treatments, with values for the Smartamine M treatment being the highest, followed by the MetaSmart and control treatments. The results indicated that both MetaSmart and Smartamine M are effective in providing metabolizable Met, but clarification of their relative contributions to metabolizable Met is still needed.     

Effect of the duration of feeding of a protein‐free diet on endogenous ileal nitrogen and amino acid loss in the growing pig

The aim of the study was to determine whether endogenous nitrogen and amino acid excretions at the terminal ileum change over time in the growing pig fed a protein‐free diet for 8 days. Seven entire male pigs with an overall mean live weight of 81.6 kg (SEM 3.3 kg) and surgically implanted post‐valve T caecum cannulas were fed a semi‐synthetic casein‐based diet for 8 days. Food was withheld from the pigs for 24 h, after which they were fed a protein‐free diet for a further 8 days at a rate of 10% of metabolic body weight per day. Chromic oxide was included in the protein‐free diet as an indigestible marker. Ileal digesta were collected continuously from 13:00 to 18:00 h on each day of the experimental period. Endogenous ileal nitrogen flows were determined for each pig each day the protein‐free diet was given, and endogenous ileal amino acid flows for the first and eighth days. There were no significant (P > 0.05) effects of the duration of feeding of the protein‐free diet on endogenous ileal total nitrogen or amino acid flows, except for the amino acids glycine and cysteine, the flows of which significantly decreased over the 8 day period (P < 0.01 and P < 0.05 for glycine and cysteine respectively), from (mean ± SEM) 1639 ± 217 to 892 ± 212 µg g⁻¹ dry matter intake (DMI) for glycine and from 173 ± 13 to 127 ± 19 µg g⁻¹ DMI for cysteine. The relative contributions (moles of each amino acid as a proportion of total moles of amino acids) of threonine, glycine and cysteine decreased significantly (P < 0.05) and that of proline increased significantly (P < 0.05) during the 8 days that the protein‐free diet was fed to the pigs. © 2000 Society of Chemical Industry     

Effects of Selenium and Methionine Supplementation of Breeder Hen Diets on Selenium Concentration and Oxidative Stability of Lipids in the Thigh Muscles of Progeny

ABSTRACT:  The effects of dietary supplementation to female chickens with selenium (Se) and methionine (Met) on the next generation were studied. Lang-shan breeding hens (450) were obtained at 52 wk of age and randomly allotted to 9 treatments; 5 replicates of each treatment were carried out. The breeders were fed a basal corn–soybean meal diet (0.13 mg Se/kg) supplemented with 0, 0.30, or 0.60 mg/kg Se from Sel-Plex and 0.32%, 0.40%, or 0.54% Met for the 30-d adapting period and 70-d experiment period. Se and glutathione (GSH) concentrations, glutathione peroxidase (GSH-Px) activity, and the oxidative stability of muscular lipids of 90-d progeny were determined by testing the TBARS values. When breeders received the highest levels of Met or Se, GSH-Px activity was decreased, the Se concentration and the oxidative stability of muscular lipids were increased with the supplementation of Se or Met. When breeder hens were given a Met-deficient diet, supplementing with Se decreased the Se deposition in progeny thigh. With regard to lipid oxidation, 0.3 mg/kg maternal dietary Se supplementation decreased the oxidative stability of muscle lipid and 0.6 mg/kg Se supplementation showed no difference from the control. When breeders were fed a Se-deficient diet, the GSH-Px activity was increased significantly and the oxidative stability of progeny muscles was decreased with the supplementation of Met. It was concluded that supplementation of the maternal diet with higher Se and Met can increase Se deposition in progeny muscle and lead to more effective protection against lipid oxidation in progeny thighs.     

Intestinal disappearance and mesenteric and portal appearance of amino acids in dairy cows fed ruminally protected methionine

An experiment was conducted to compare the rates of disappearance of amino acids (AA) from the small intestine and their net appearance in the blood draining only the small intestine (mesenteric-drained viscera) and the whole gastrointestinal tract (portal-drained viscera) of cows fed a silage-based diet supplemented or not with ruminally protected Met. Five lactating dairy cows (118+/-4 DIM) equipped with duodenal and ileal cannulae (n = 2) or a duodenal cannula only (n = 3), two of which were multicatheterized, were fed a TMR top dressed with 0 or 72 g of ruminally protected Met per day. The addition of ruminally protected Met to the diet increased the duodenal flux of Met leading to a higher apparent digestibility of Met in the small intestine. Sixty-six percent of Met from ruminally protected Met bypassed the rumen and 82% of that Met disappeared from the small intestine. Arterial plasma Met concentrations numerically increased with ruminally protected Met (45 vs. 18 microM), while total AA concentration decreased. Feeding ruminally protected Met resulted in higher concentrations of urea-N and glucose in arterial plasma. Milk production and milk composition were unaffected. The disappearance of essential AA across the small intestine was equivalent (101%) to their flux through the mesenteric-drained viscera while the portal:mesenteric-drained viscera flux ratio for each essential AA varied from 38% for Thr to 76% for Phe. The portal:mesenteric-drained viscera flux ratio for Met was 66%. These results confirm observations made with pigs and sheep.     

Uptake of α-tocopherol in porcine plasma and tissues

The effect of feeding α-tocopheryl acetate to pigs on the rate and extent of uptake of α-tocopherol in various tissues was investigated. The rate of iron ascorbate-induced lipid peroxidation was also studied. One hundred and eight Landrace × Large White pigs were assigned at random to one of the following barley-based diets: 20 mg α-tocopheryl acetate/kg feed for up to 126 days; 20 mg/kg feed to day 91, followed by 200 mg/kg feed to day 126, or 200 mg/kg feed for up to 126 days: Pigs from each group were slaughtered at specified intervals. For pigs fed the diet supplemented with 200 mg α-tocopheryl acetate/kg feed, α-tocopherol levels increased with increasing supplementation time up to day 126 in all tissues studied. The highest levels of α-tocopherol were observed in kidney fat and subcutaneous fat (inner layer) followed by subcutaneous fat (outer layer), liver, lung, heart, kidney, with muscle and brain containing approximately the same level. The α-tocopherol concentrations in all tissues examined, from pigs fed 200 mg α-tocopheryl acetate/kg feed from weaning to day 126 were greater than those fed the supplemented diet for 35 days. Iron-induced lipid peroxidation was reduced by dietary α-tocopheryl acetate supplementation, and muscle samples from pigs supplemented for 126 days were significantly (p < 0.05) less susceptible to peroxidation compared to muscle from pigs fed the same supplemented diet for 35 days.     

Body composition and feed intake of young pigs postweaning

Thirty-five female Large White pigs were weaned at 14 days of age, penned individually, given a single diet and slaughtered serially at 25, 40, 55 and 70 days of age. A control group was fed to appetite throughout while three groups were subjected to feed restriction at various ages postweaning. For the periods 25 to 40, 40 to 55, 55 to 70 days of age pigs fed to appetite gained 321 (±19.9), 532 (±35.4) and 601 (±35.5) g liveweight day^?1. Pigs restricted between 25 and 55 days, followed by refeeding from 55 to 70 days, gained 192 (±14.0), 169 (±44.8) and 508 (±81.0) g liveweight day^?1; pigs restricted between 40 and 55 days, followed by refeeding from 55 to 70 days, gained 425 (±42.8), 409 (±49.6) and 480 (±70.1) g liveweight day^?1. A group given 200 g feed day^?1 gained 42 (±4.2) g liveweight daily between 25 and 70 days. Refed groups did not differ significantly from controls in their feed intakes for the period 55 to 70 days, either in absolute intakes or in feed intake kg^?1 mean liveweight. Refed pigs grew no faster, and made no greater protein gains than controls of equivalent weight; however, lipid gains were elevated.     

Effect of feeding different diets on the exocrine pancreatic secretion of nitrogen,amino acids and enzymes in growing pigs

Five barrows were fitted with permanent pancreatic re-entrant cannulas to determine the influence of diet on exocrine pancreatic secretions in the weight range from 40 to 65 kg. The pigs were fed four diets. Diets 1 and 2 were based on corn starch and contained 18.6 and 16.9 % crude protein (dry matter basis) from soybean meal and canola meal, respectively. Diets 3 and 4 contained 93.9 % wheat and barley, respectively. In the same order, the crude protein contents (dry matter basis) of these diets were 14.4 and 11.2%, respectively. The experiment was carried out according to 4 × 4 Latin square design. Each experimental period comprised 12 days. Following an adaptation period of 8 days, pancreatic juice was collected from 08:00 on day 9 to 08:00 h on day 10 and from 08:00 on day 11 to 08:00 h on day 12. The pigs were fed twice daily, at 08:00 and 20:00 h, 800 g each meal. Despite large differences, up to 23%, between the overall mean values of the parameters that were measured there was no effect (P > 0.05) of diet on the volume of secretion of pancreatic juice, the pH and the secretion of total and TCA-precipitable nitrogen. Due to the high level of within-study variation there was also no effect (P > 0.05) of diet on the secretion of amino acids and the total activity of trypsin, chymotrypsin, α-amylase and lipase in pancreatic juice.