The effect of gastric loads of sugars and amino acids on milk intake of suckling pigs

A 3 h fast of suckling pigs less than a week of age decreased plasma glucose (P less than .005), but did not affect plasma protein, osmolality or hematocrit. After fasting, solutions (40 ml/kg body weight) of 5% glucose, 5% fructose, 5% xylose, 5% mannitol, 5% sorbitol, 2.5% leucine, 2.5% phenylalanine (50 ml/kg), .9% NaCl, 5% lactose, 5% sucrose and a 50% egg yolk-distilled water mixture were administered by stomach tube and the piglet then returned to the sow. Weight gain was used as a measure of sow's milk intake. Milk consumption during the first 3 h after fasting was lower (P less than .05) for pigs given glucose than for sham-loaded controls, but no differences were observed between glucose and mannitol or sorbitol for the same period. Mannitol and sorbitol were more effective than NaCl (P less than .01) in lowering consumption for the 3 h after loading. Also during the first hour after loading, xylose caused lower (P less than .001) food intake than glucose. Egg yolk suppressed intake in comparison to sham-loaded controls (P less than .05). D-phenylalanine suppressed intake more than L-phenylalanine (P less than .05), but no differences were observed between the D and L isomers of leucine.     

母猪日粮中支链氨基酸水平对仔猪血液生化指标和部分免疫指标的影响

试验探讨了母猪日粮中添加支链氨基酸对哺乳仔猪血清生化指标和部分免疫指标的影响。选取胎次、体况、分娩期相近的法系(JALAX)母猪144头,随机均分成3个处理(对照组、处理A和处理B),每个处理6个重复,每个重复8头母猪。对照组饲喂基础日粮(总支链氨基酸为3.24%,缬氨酸:赖氨酸=0.86:1),处理A日粮添加低水平支链氨基酸(总支链氨基酸为3.56%,缬氨酸:赖氨酸=1.10:1),处理B日粮添加高水平支链氨基酸(总支链氨基酸为3.74%,缬氨酸:赖氨酸=1.20:1)。试验结果表明:①支链氨基酸添加组仔猪10、21日龄血清尿素氮水平有所降低,但10日龄血糖的浓度显著提高(P<0.05);②低水平支链氨基酸显著提高了10日龄仔猪血清白蛋白浓度(P<0.05)以及10、21日龄血清中乳酸脱氢酶活性(P<0.01);③与对照组相比,支链氨基酸的添加极显著提高了10、21日龄仔猪血清中IgG的浓度(P<0.01)。这说明母猪日粮中添加支链氨基酸能通过母体效应进而影响仔猪生长发育与免疫功能,但作用效果与添加水平有关。     

Utilization of milk amino acids by the suckling Iberian piglet

Sixteen pure-bred Iberian (IB) sows were used in two trials to determine the efficiency of utilization of milk protein and amino acid (AA) for growth in suckling piglets. It was hypothesized that there may be one or more strongly limiting essential AA (EAA) responsible for the slow rate of growth of the IB piglet. This AA will show the highest fractional retention. Daily milk yield and composition were determined weekly over a 34-day lactation period. Within each litter, one piglet at birth and four piglets on d 35 of life were slaughtered. The protein content of the IB sow milk was similar to that reported for conventional breeds. However, branched-chain AA, Thr, Pro, Asp and Ala were in concentrations somewhat below the range of literature values and Arg and Met, substantially above it. Milk intake per piglet tended to be greater in Trial 2 (832 vs. 893 g/day respectively; p = 0.066). However, the IB piglets grew at 168 ± 3.3 g/day, irrespective of the trial. The whole-body protein of piglets at weaning and the protein deposited in their body during the lactating period showed very close AA pattern. Among EAA, His and Arg show the highest fractional retentions (g AA retained/g AA ingested) in whole-body tissues (1.019 ± 0.025 and 0.913 ± 0.017 respectively) and also the highest body to milk ratios (1.50 and 1.41 respectively). Gly and Ala presented, among non essential AA, the highest efficiencies of utilization for tissue deposition (1.803 ± 0.057 and 1.375 ± 0.026 respectively) and body to milk ratios (2.75 and 2.12 respectively). These results suggest that the low efficiency of utilization of milk protein and the low rate of gain of the IB suckling piglet can be explained by a marked shortage in His supply, in addition to the suboptimal milk provision of Arg, Gly and Ala.     

Gastrointestinal zygomycosis in suckling pigs

Gastrointestinal zygomycosis was diagnosed in 3 suckling pigs (10, 14, and 28 days old) with diarrhea that was unresponsive to treatment with broad-spectrum antibiotics. The 3 pigs were from separate farms, and littermates of the 3 pigs with similar clinical signs had died. At necropsy, 2 of the 3 pigs had catarrhal to fibrinonecrotic gastroenteritis, and the third pig had hemorrhagic gastritis without intestinal lesions. Microscopically, transmural necrosis of the stomach and intestines was associated with marked inflammatory cell infiltration and thrombosis and vasculitis of vessels of the lamina propria and submucosa. Numerous broad, irregularly branching, nonseptate, mucoraceous fungi were seen in the lumens of blood vessels and in the necrotic mucosa and submucosa.     

Some effects of protein deficiency in young growing pigs. II. Blood plasma free amino acids

The influence of protein deficiency, rehabilitation and total starvation on the free amino acid levels in the blood plasma of pigs has been investigated. It was found that the concentration of most amino acids was reduced during protein deficiency. The levels of leucine, isoleucine and valine were diminished by the greatest proportion, followed by threonine, tyrosine and citrulline. During the first few weeks of protein deficiency the levels of lysine, histidine and arginine were slightly increased, but later decreased below control values. Concentrations of glycine and alanine were altered in a similar way except that the initial increase was much more pronounced. The concentrations of most of these amino acids returned to control levels after rehabilitation. Total starvation led to an increase in concentration of leucine, isoleucine, valine, threonine and to a smaller extent phenylalanine, lysine, citrulline and arginine. The concentration of glycine, alanine and glutamic acid were very much reduced. The level of urea in the circulation dropped reversibly during protein deficiency and increased very much during total starvation.     

Impact of dietary tryptophan and behavioral type on growth performance and plasma amino acids of young pigs

Tryptophan (TRP) content in the protein of the weaning diet was varied from deficient (.70 g/16 g N) to adequate (1.15 g/16 g N) and excess (1.60 g/16 g N) in diets fed to 108 pigs from d 5 to d 26 after weaning (W) and in 72 pigs from d 26 after weaning to slaughter (100 kg live weight) to assess immediate and long-term effects of TRP on performance. Daily weight gain and feed efficiency were improved when dietary TRP was increased from deficient to adequate (+60 and +40%, respectively). Concurrently, daily feed intake was elevated moderately (+15%). No further improvement was observed with excess TRP. In the low TRP group, gain/feed was significantly poorer up to 25 kg live weight, but this effect did not continue later. Although no compensatory growth could be shown in the group fed the deficient diet, growth retardation was very small (1.5%; P greater than .10) at slaughter. Early changes in TRP supply did not affect either carcass or meat quality. Behavioral reactivity, as determined on day W + 5 in an "open-field" test, did not affect early performance, but growth rate during the growing-finishing stage (3.2%) or the whole period (2.5%) was greater by nonemotional than by emotional pigs. Plasma amino acid contents in blood samples, withdrawn on day W + 15 (fed state) and W + 17 (fasted state), were consistent with the effect of TRP on growth rates. However, in the fasted state, a diet x reactivity interaction suggested that TRP removal from the plasma was less rapid in nonemotional than in emotional pigs. Furthermore, increased plasma concentrations of essential amino acids and urea in the latter group suggested that protein and amino acid catabolism was more rapid in emotional than in nonemotional pigs. These data are discussed relative to the effect of the behavioral type of pig on its TRP requirement.     

评定猪饲料氨基酸营养价值的体外法

评定饲料氨基酸生物学效价的体外方法有化学方法、微生物方法、酶解方法和远红外反射光谱分析技术,本文对各种方法的优缺点作了分析和比较,从而为合理地评定猪饲料蛋白质氨基酸的营养价值提供了理论依据。     

Chronic lung inflammation affects plasma amino acid concentrations in pigs

Metabolic changes associated with inflammatory processes and immune response can modify protein and AA requirements. Improved knowledge of these processes will provide opportunities for nutritional intervention to sustain growth and animal defense at the same time. The objective of the study was to identify AA whose metabolism is affected by chronic lung inflammation. Six pairs of littermate piglets were selected at 28 d of age on the basis of their BW. After catheterization of the jugular vein, one littermate received complete Freund's adjuvant (CFA) intravenously, whereas its littermate was injected with a sterile saline solution (CON). Piglets within a litter were pair-fed in order to avoid confounding effects of feed intake and inflammation on plasma AA concentrations. Blood samples were taken after an overnight fast and 2 h after the morning meal for 9 d. Rectal temperature, food consumption, weight gain, plasma haptoglobin, and AA concentrations were measured. The CFA injection decreased food intake, and increased body temperature and plasma haptoglobin concentration. Plasma tryptophan, glutamine, proline, glycine, tyrosine, ornithine, total AA concentrations, and the ratio of tryptophan to large neutral AA were less in CFA than in CON (P < 0.05), independent of time and meal. In contrast, plasma histidine concentration was higher (P < 0.05) in CFA than in CON pigs. Plasma serine, arginine, alanine, asparagine, and total AA concentrations were lower in CFA than in CON pigs only in the fed state (P < 0.05). Among essential AA, only plasma tryptophan concentration was lower (P < 0.01) in CFA than in CON pigs in both fasted and fed state. These results show that chronic lung inflammation affects individual AA differently and suggest that the utilization of some AA increased during chronic lung inflammation in pigs. Activation of tryptophan catabolism enzyme indoleamine 2,3-dioxygenase seems a relevant hypothesis to explain the increased tryptophan utilization, although its incorporation in acute-phase proteins and the existence of other catabolic pathways cannot be excluded.     

Ileal digestibility of amino acids in pigs fed barleys differing in protein content

The apparent digestibility of nitrogen and amino acids was measured by the ileal and faecal methods in pigs fed nine barleys differing in nitrogen content (from 1.73 to 2.16 per cent/DM). A positive (r = 0.87) and significant relationship was found between the apparent nitrogen digestibility at the end of the ileum and the crude protein content of barley. Generally, the higher the protein of the grain, the higher the ileal digestibilities of the amino acids. For most amino acids the faecal values were greater than the ileal ones. This being specially so for threonine, tryptophan, histidine and cystine belonging to the nutritionally important amino acid group. When the relationship between the amino acid and nitrogen digestibilities at the level of ileum is considered, the values were found to be similar to that of nitrogen in the case of tryptophan, higher for isoleucine, valine (both 2-3 units), cystine, histidine, leucine, methionine (all 5-6 units) and phenylalanine (10 units) and lower only for lysine and threonine (7-8 dig. units).     

液态或颗粒饲料添加精氨酸对21～42 d断奶仔猪生长性能和血浆氨基酸水平的影响

文章旨在研究饲喂颗粒料或液态料以及日粮添加精氨酸对断奶仔猪生长性能及血浆必需氨基酸和非必需氨基酸含量的影响。试验选择21 d断奶的健康仔猪672头,随机分为4组,每组6个重复,每个重复28头。试验日粮采用2×2多因素方差设计,2种饲料形态(液态料或颗粒料),2个精氨酸水平(0或6 g/kg精氨酸),试验共进行21 d。断奶后前10 d饲喂液态料较颗粒料显著改善了仔猪的平均日采食量、平均日增重和料比(P<0.05);在断奶后第11~13天液态料向颗粒料过渡阶段,液态料组较颗粒料组对日增重和料比具有负面影响(P<0.05);饲料形态和添加精氨酸以及饲料形态和仔猪日龄对断奶仔猪的平均日采食量的影响具有显著交互效应(P<0.05)。断奶后前10 d,饲喂液态料的仔猪较颗粒显著提高了干物质摄入量(P<0.05);断奶后前10 d饲喂添加精氨酸的液态料仔猪,由液态料向固体料过渡,显著提高了采食量和日增重(P<0.05)。液态或颗粒饲料添加精氨酸显著降低了断奶仔猪血浆尿素氮含量(P<0.05);饲喂液态料的断奶仔猪在28和37 d较颗粒料组显著降低了血浆尿素氮含量(P<0.05)。除了色氨酸、组氨酸、谷氨酸和甘氨酸外,液态料较颗粒料均显著提高了断奶仔猪血浆氨基酸水平(P<0.05);颗粒料或液态料添加精氨酸显著提高了断奶仔猪血浆亮氨酸、异亮氨酸、精氨酸和甘氨酸水平(P<0.05)。综上所述,断奶后仔猪饲喂液态料可以提高生长性能,但无论颗粒料还是液态料添加精氨酸均可以显著提高血浆精氨酸水平,降低尿素氮含量。     

Effect of dietary excess of branched‐chain amino acids on performance and serum concentrations of amino acids in growing pigs

Depressed performance and availability of some amino acids (AA) in pigs fed excess Leu diets appear to be related to lower feed intake. Surplus Ile and Val may help to overcome this effect. An experiment was conducted with 24 pigs (31.8 ± 1.2 kg initial BW) to evaluate the effect of dietary excess of either Leu alone or with surplus Ile and Val on performance and serum concentration (SC) of essential AA. Treatments were as follows: T1, basal diet; T2, basal plus 0.43% L‐Leu (excess Leu); T3, basal added with 0.43% L‐Leu, plus 0.20% L‐Ile and 0.25% L‐Val (excess LIV). The basal diet was formulated to contain 0.90% standardized ileal digestible Lys and added with crystalline L‐Lys, L‐Thr, DL‐Met, L‐Trp, L‐Leu, L‐Ile, L‐His and L‐Val to create essential AA:Lys ratios close to an ideal protein for growing pigs. All pigs were fed the same amount of feed twice a day (average, 3.42× the requirement of NEm). Blood samples were collected at 2.5 (absorptive) and 11.0 h (post‐absorptive) post‐prandial to analyse SC of AA. Excess of either Leu or LIV did not affect growth rate nor feed conversion. Excess Leu increased Leu SC and decreased Ile and Val SC (p < 0.05) at both absorptive and post‐absorptive phases, but excess LIV restored the SC of Ile and Val. The SC of other essential AA was not affected by excess of either Leu or LIV. The SC of all AA during absorptive, on average, was about two times higher than that of post‐absorptive phase. These results suggest that the reduced availability (SC) of Ile and Val in pigs consuming excess Leu diets is attributed to a reduced absorption and increased cellular degradation rates of them.