Organic acids in diets for entire male pigs: Effect on skatole level, microbiota in digesta, and growth performance

The effect of different organic acids in diets of entire male pigs on the concentration of skatole in colon, plasma, and adipose tissue and on the composition of the microbiota in the gastrointestinal tract was evaluated. Entire male pigs (n = 60) of sows inseminated with boars disposition for high skatole levels (31.7 and 113.2 kg initial and final body weight, respectively) were fed either control, 1.0% formic acid, 0.85 % benzoic acid, 0.85% sorbic acid, 1.2% fat coated Ca-butyrate, or 1.5% fat and inulin coated Ca-butyrate diets. All levels of organic acids corresponded to 0.85% of pure acid. Digesta samples from colon descendens were analyzed for skatole, indole, and organic acids. Digesta samples for microbiological examinations were taken from proximal jejunum, colon descendens, and rectum. There were no differences in levels of skatole, indole, or organic acid levels in colon descendens among pigs fed organic acid supplemented diets and control diet. Plasma skatole levels were significantly reduced in pigs fed diets containing formic acid or benzoic acid compared with the control, but supplementing diets with organic acids did not affect skatole levels in adipose tissue. Pigs fed organic acids had significantly lower levels of coliforms, enterococci, and lactic acid producing bacteria (LAB) in all sampling sites of the gastro-intestinal tract. Pigs fed 1.5% fat and inulin coated Ca-butyrate had less reduction in the number of coliforms and LAB in the small intestine compared with pigs fed formic, benzoic and sorbic acid. Formic acid had a stronger antibacterial effect on coliforms than benzoic or sorbic acids in the small intestine. Pigs fed diets containing formic acid, benzoic acid, or sorbic acid had significantly higher average daily gain and better feed conversion ratio (FCR) than the control pigs during the grower phase, and tended to improve FCR during the overall period. The inclusion of fat coated Ca-butyrate or fat and inulin coated Ca-butyrate had no effect on growth performance of the pigs. In conclusion, supplementing diets with different organic acids reduced number of coliforms, enterococci, and LAB in the gastrointestinal tract, but did not affect skatole levels in colon or adipose tissue of entire male pigs.     

Effect of live weight and dietary supplement of raw potato starch on the levels of skatole, androstenone, testosterone and oestrone sulphate in entire male pigs

This study evaluated the effect of supplement of raw potato starch (RPS) on the levels of skatole, androstenone, testosterone and oestrone sulphate in plasma from entire male pigs. The study also evaluated relationships between plasma levels of skatole and testicular steroids at three different live weights (LW) of approximately 90, 100 and 115 kg. A total of 111 entire male pigs of a crossbred (Yorkshire dams×Swedish Landrace sires) were used. Animals were raised either in mixed pens, with females and males, or single-sex pens. Each pen contained seven or nine pigs. The most fast-growing three pigs from the pens with nine pigs were slaughtered when they reached 90 kg LW, and the remaining pigs were slaughtered at 115 kg LW. All pigs were fed the same commercial diet until the average pen weight reached 100 kg. Then, 33 out of 80 remaining pigs received RPS, 0.6 kg per pig and day, for 2 weeks prior to slaughter. Blood samples were taken from the pigs at three occasions: first, the day prior to first slaughter occasion, low-weight group; second, the day prior to change in diet, middle-weight group; and third, the day prior to second slaughter occasion, high-weight group. Plasma was analysed for the levels of skatole, androstenone, testosterone and oestrone sulphate. Fat samples were taken at slaughter and analysed for the levels of skatole and androstenone. The levels of skatole and testicular steroids in plasma were significantly higher in entire male pigs from the high-weight group fed no RPS compared to those from low- and middle-weight groups. The levels of the investigated compounds did not differ between low- and middle-weight groups (P>0.1). The diet with RPS induced a decline in skatole levels in plasma and fat (P<0.001), but not plasma levels of testicular steroids and fat levels of androstenone (P>0.05). Skatole levels were positively correlated to testosterone and oestrone sulphate levels in the middle- and high-weight pigs fed no RPS as well as to testosterone in the low-weight group. In the high-weight group fed RPS, skatole levels were not correlated to any of the analysed compounds. Approximately 26% of the entire male pigs (11 out of 43) from the high-weight group fed no RPS produced skatole levels in fat above 0.20 μg/g, whereas the pigs from the low- and high-weight group fed RPS did not produce skatole levels above 0.20 μg/g in fat. Androstenone levels in fat were high in all groups. In total 47% (52 out of 111) pigs expressed androstenone levels above the rejection levels in fat of 1.0 μg/g and 88% (98 out of 111) had androstenone levels above 0.5 μg/g. It was concluded that a lower slaughter weight and the supplement of raw potato starch to the diet could be used to reduce skatole levels in entire male pigs. Androstenone levels in fat, however, could not be reduced by either a lower weight at slaughter or dietary manipulation.     

The effect of removing animals for slaughter on the behaviour of the remaining male and female pigs in the pen

The study was performed to investigate changes in the behaviour of male and female pigs when one or more pigs were removed from the pen and sent to slaughter. Twelve pens were included, half of them housed six female pigs each, while the other half housed six male pigs each. Skin lesions and behaviour were recorded on two occasions, four days before and two days after one or more animals per pen were sent to slaughter. On the first occasion the male pigs fought on average about twice as often as the females (2.6 vs. 1.0 per animal per hour) and had twice as many skin lesions (6.7 vs. 3.2). On the second occasion, the frequency of fighting among both males (6.8) and females (1.8) had increased, however, more in males than in females. The number of skin lesions was not significantly higher on the second occasion. In the male group there was also a tendency towards increased mounting on the second occasion (from 2.3 to 3.3 per animal per hour). The study shows that the very common practice of slaughtering pigs from one pen over more than one occasion results in an increase in unwanted behaviour. The effect is more pronounced in groups of entire male pigs than in groups of females.     

Effect of single-sex or mixed rearing and live weight on performance,technological meat quality and sexual maturity in entire male and female pigs fed raw potato starch

Abstract

The aim of our study was to investigate the effect of rearing system (mixed or single-sex) on performance and carcass quality of entire male and female pigs slaughtered at around 90 or 115 kg live weight. We also studied the combined effect of live weight and dietary supplement of raw potato starch (RPS) on technological meat quality for both sexes, and boar taint compounds in entire male pigs. Furthermore, we investigated pre-slaughter routines (pen-wise or mixing with unfamiliar pigs) and sexual maturity. A total of 408 growing/finishing pigs were included in this two-year study. Performance did not differ significantly between entire male and female pigs irrespective of rearing system, except for daily weight gain in the interval from 90 kg to slaughter. Mixed pigs had significantly higher daily weight gain in this interval than single-sex pigs. Entire male pigs had higher carcass lean meat content than female pigs (1.6 percentage units). Technological meat quality differed only slightly between the sexes. Females reared in mixed pens were sexually more mature than female pigs reared in single-sex pens, and mature females had higher growth rate but lower meat content in carcasses than immature females. In contrast, female contact did not influence sexual maturity of entire male pigs. Mixing entire male pigs with unfamiliar pigs at the abattoir resulted in more damaged skin compared with pen-wise keeping whereas female pigs had almost no visible skin damage. We therefore recommend that entire male pigs are not mixed with unfamiliar pigs during transport and at the abattoir, because of fighting and subsequent skin damage. The levels of skatole in fat were significantly lower in high-weight entire male pigs fed RPS compared to high-weight pigs without RPS. Androstenone levels in fat were high in all groups.     

Ileal digestibility of amino acids,phosphorus, phytate and energy in pigs fed sorghum‐based diets supplemented with phytase and Pancreatin®

The effects of phytase supplementation on the apparent ileal digestibility (AID) of amino acids (AA) have been inconsistent. Two experiments evaluated the effect of providing a mixture of pancreatic enzymes (Pancreatin^®) to growing pigs fed sorghum–soybean meal diets supplemented with phytase on the AID of AA, energy, and phosphorus (P), as well as the ileal digestibility (ID) of phytate; there were four periods per experiment. In Experiment 1, eight pigs (BW 22.1 ± 1.3 kg) were fitted with a T‐cannula at the distal ileum. Each period consisted of 9 days; 7 days for diet adaptation, and 2 days for digesta collection. Treatments (T) were: (i) basal sorghum–soybean meal diet, (ii) basal diet plus Pancreatin^®, (iii) basal diet plus phytase and (iv) basal diet plus phytase and Pancreatin^®. Phytase increased the digestibilities of phytate and P (p < 0.001), but did not affect the AID of AA and energy (p > 0.10). Except for methionine (p = 0.07), Pancreatin^® did not affect the AID of AA. Phytase and Pancreatin^® did not interact (p > 0.10). Experiment 2 was similar to Experiment 1, but Pancreatin^® was infused into duodenum. Pancreatin^® infusion did not affect the AID of AA (p > 0.10); and tended to reduce (p = 0.09) the AID of lysine. Phytase × Pancreatin^® interactions were not observed (p > 0.10). In conclusion, phytase and Pancreatin^® did not improve the AID of AA in growing pigs fed sorghum–soybean meal diets indicating that phytates did not affect AA digestibility.     

Apparent and standardized ileal digestibility of amino acids in diverse barley cultivars fed to growing pigs

The objectives of this study were to determine the chemical composition, ileal amino acid (AA) digestibility of barley varieties and to develop equations to predict the AA digestibility based on the chemical characteristics of individual barley. A wide selection of nine barley varieties in the main growing regions of China was used in the experiment. Ten crossbred pigs (30.9 ± 1.8 kg) were allotted to a 6 × 10 Youden Square. The treatments included a nitrogen‐free diet and nine barley test diets. Considerable variation was observed in the content of neutral detergent fiber, acid detergent fiber, crude protein (CP) and all AAs among the barley samples. The standardized ileal digestibility (SID) of indispensable AAs with the exception of arginine, phenylalanine and threonine were different (P < 0.05) among the nine barley sources tested. With R² values exceeding 0.50, significant linear regression equations for CP and threonine were obtained. In conclusion, significant differences existed in the ileal digestibility of CP and AAs among barley varieties. It is difficult to predict the SID of most of the amino acids in barely based upon chemical characteristics.     

Optimum tryptophan: Lysine ratio in diets for growing pigs: Analysis of literature data

Optimum tryptophan supply in diets for growing pigs shows considerable variation between studies; therefore, an attempt was made to analyse all available data reported in the literature. Due to the fact that, in most studies, lysine was the second-limiting amino acid, which means that lysine limits growth at a certain level of tryptophan intake, optimum supply has to be expressed as a ratio to lysine. The database was too small to give optimum supply as a concentration in the diet or as a daily amount. In total, 33 experiments were found, where tryptophan intake was offered in graded levels resulting in a tryptophan-dependent and -independent response phase. An additional 13 experiments showed either no dependent or no independent phase, which did not allow an optimum determination. The optimum tryptophan : lysine ratio (T : L_opt) was defined as the beginning of the plateau response-phase in feed intake or body weight gain. Mean T : L_opt was 0.174 (SD = 0.023; n = 33) and seemed to be unaffected by body weight, growth rate, lysine and protein concentration in the diet, or genetic improvement of the animals. However, precise detection of the optimum ratio is generally restricted due to the relatively large intervals between the ratios tested in the respective studies. Mean difference between T : L_opt and the nearest T : L ratio tested below (T : L_opt − 1) was 0.028 (SD = 0.011; n = 32). Therefore, it is likely that the true optimum ratio is below 0.174, and that the mean of both ratios ((T : L_opt + T : L_opt − 1) / 2) can be taken as a good estimation (mean = 0.160; SD = 0.024; n = 33). With respect to feed formulation for growing pigs, it was concluded that a figure of 0.17 for the optimum T : L ratio includes a safety margin large enough to cover most of the biological variations.     

Dietary levels of protein and free amino acids affect pancreatic proteases activities,amino acids transporters expression and serum amino acid concentrations in starter pigs

The dietary contents of crude protein and free amino acids (AA) may affect the protein digestion and AA absorption in pigs. Trypsin and chymotrypsin activities, AA serum concentrations and expression of AA transporters in the small intestine of pigs fed a low protein, AA‐supplemented (19.2%, LPAA) or a high protein (28.1%, HP), wheat‐soybean meal diet were measured in two 14‐d trials. The LPAA diet contained free L‐Lys, L‐Thr, DL‐Met, L‐Leu, L‐Ile, L‐Val, L‐His, L‐Trp and L‐Phe. All pigs were fed the same amount of feed (890 and 800 g/d for trial 1 and 2 respectively). In trial 1, samples of mucosa (duodenum, jejunum and ileum) and digesta (duodenum and jejunum) were collected from 14 pigs (17.2 ± 0.4 kg); in trial 2, blood samples were collected from 12 pigs (12.7 ± 0.3 kg). The trypsin and chymotrypsin activities in both intestinal segments were higher in pigs fed the HP diet (p < 0.01). Trypsin activity was higher in jejunum than in duodenum regardless the dietary treatment (p < 0.05). Pigs fed the LPAA diet expressed more b^0,+AT in duodenum, B⁰AT1 in ileum (p < 0.05), and tended to express more y⁺LAT1 in duodenum (p = 0.10). In pigs fed the LPAA diet, the expression of b^0,+AT was higher in duodenum than in jejunum and ileum (p < 0.01), but no difference was observed in pigs fed the HP diet. Ileum had the lowest b^0,+AT expression regardless the diet. The serum concentrations of Lys, Thr and Met were higher in LPAA pigs while serum Arg was higher in HP pigs (p < 0.05). Serum concentrations of AA appear to reflect the AA absorption. In conclusion, these data indicate that the dietary protein contents affect the extent of protein digestion and that supplemental free AA may influence the intestinal site of AA release and absorption, which may impact their availability for growth of young pigs.     

Chicory (Cichorium intybus L.) and cereals differently affect gut development in broiler chickens and young pigs

Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastrics. Furthermore, it can be used as in-feed antibiotic alternative. Chicory (Cichorium intybus L.) forage with high content of pectin (uronic acids as building blocks) is a novel class of dietary fiber that is chemically different from cereal grains (with high content of arabinoxylans). In the present study, we investigated effects of dietary inclusion of chicory forage on digestibility, gut morphology and microbiota in broilers and young pigs. In the chicken experiment, 160 1-d old broiler chicks were fed 3 nutritionally balanced diets for 30 d including a cereal-based diet and 2 diets with part of the cereals substituted with 60 and 120 g/kg chicory forage (CF60 and CF120), whereas in the pig experiment, 18 seven-wk old Yorkshire pigs were fed 3 diets for 18 d including a cereal-based diet and 2 diets with 80 and 160 g/kg chicory forage inclusion (CF80 and CF160). Our results showed that young pigs were capable to utilize chicory forage well with higher total tract apparent digestibility (TTAD) of all fiber fractions, particularly uronic acid, compared with the control (P < 0.01). In contrast, a decreased TTAD of all fiber fractions was observed in chickens fed on diet CF120 (P < 0.05). Moreover, diet induced changes in gut morphology were observed in the large intestine of chickens. The alteration of cecal mucosal thickness was further positively correlated with TTAD of non-starch polysaccharides (NSP) and its constituent sugars (P < 0.05). In addition, in pigs, terminal restriction fragment length polymorphism (T-RFLP) analysis of intestinal microbiota revealed substantial dietary effects (cereal control diet vs. chicory forage inclusion) on the relative abundance of 2 dominant bacterial phylotypes (Prevotella sp. vs. Roseburia sp.) respectively (P < 0.05). In conclusion, our data showed that chicory forage (Cichorium intybus L.), a novel dietary fiber source in animal nutrition, have potential beneficial properties as fiber ingredient in diets for both pigs and chickens.     

Chicory （Cichorium intybus L.） and cereals differently affect gut development in broiler chickens and young pigs

Dietary fiber, resistant to host-mediated digestion in the small intestine due to lack of endogenous enzymes, impacts many facets of animal health and is associated with gut development especially in young monogastrics. Furthermore, it can be used as in-feed antibiotic alternative. Chicory （Cichorium intybus L.） forage with high content of pectin （uronic acids as building blocks） is a novel class of dietary fiber that is chemically different from cereal grains （with high content of arabinoxylans）. In the present study, we investigated effects of dietary inclusion of chicory forage on digestibility, gut morphology and microbiota in broilers and young pigs. In the chicken experiment, 160 1-d old broiler chicks were fed 3 nutritionally balanced diets for 30 d including a cereal-based diet and 2 diets with part of the cereals substituted with 60 and 120 g/k9 chicory forage （CF60 and CF120], whereas in the pig experiment, 18 seven-wk old Yorkshire pigs were fed 3 diets for 18 d including a cereal-based diet and 2 diets with 80 and 160 g/kg chicory forage inclusion （CF80 and CF160）. Our results showed that young pigs were capable to utilize chicory forage well with higher total tract apparent digestibility （TTAD） of all fiber fractions, particularly uronic acid, compared with the control （P 〈 0.01）. In contrast, a decreased TTAD of all fiber fractions was observed in chickens fed on diet CF120 （P 〈 0.05）. Moreover, diet induced changes in gut morphology were observed in the large intestine of chickens. The alteration of cecal mucosal thickness was further positively correlated with TTAD of non-starch polysaccharides （NSP） and its constituent sugars （P 〈 0.05）. In addition, in pigs, terminal restriction fragment length polymorphism （T-RFLP） analysis of intestinal microbiota revealed substantial dietary effects （cereal control diet vs. chicory forage inclusion） on the relative abundance of 2 dominant bacterial phylotypes （Prevotella sp. vs. Roseburia sp.） respective     

精油对生长猪蛋白质和氨基酸等回肠末端表观消化率的影响

试验旨在通过采用T型瘘管法,研究精油对生长猪蛋白质和氨基酸等回肠末端表观消化率的影响。试验选用6头(杜×长×大)去势公猪([28.6±1.3)kg],采用3×3双拉丁方试验设计,分别饲喂正对照日粮:玉米-豆粕型基础日粮+抗生素;负对照日粮:无抗基础日粮;精油组日粮:负对照+0.01%精油。每个试验期为7 d,前5 d为适应期,后2 d为食糜收集期。结果表明,在日粮中添加精油可提高(P<0.05)蛋白质、能量、精氨酸、赖氨酸、亮氨酸、色氨酸、蛋氨酸、丙氨酸、总必需氨基酸、总氨基酸的回肠末端表观消化率,并有提高干物质、苏氨酸、天冬氨酸、丝氨酸和酪氨酸表观消化率的趋势(P<0.10)。在日粮中添加0.01%的精油可提高生长猪蛋白质、能量、总必需氨基酸和总氨基酸的回肠末端表观消化率,并有提高干物质表观消化率的趋势。     

Standardized ileal digestibility of amino acids in European soya bean and rapeseed products fed to growing pigs

This study was conducted to determine the chemical composition and standardized ileal digestibility coefficients (SID) of crude protein (CP) and amino acids (AA) of European soya bean and rapeseed products in pigs. Six soya bean and two rapeseed products were used as the sole dietary source of CP and AA, including raw (FFSB) and roasted full‐fat soya beans (FFSB_Roasted), soya bean (SBC) and rapeseed cake (RSC), and rapeseed meal (RSM) from Bavaria (Germany), soya bean meal (SBM) from the Danube region (Austria; SBM_Austria), a commercially available standard SBM (SBM_Std) and an imported genetically modified organism‐free SBM (SBM_GMO‐free). Eight ileal‐ cannulated pigs with an initial body weight of 32 ± 2 kg were allotted to a row‐column design with eight diets and six periods of seven days each. Trypsin inhibitor activity (TIA) ranged from 1.8 in SBM_Std to 24.5 mg/g DM in FFSB. The SID of CP and all AA in FFSB_Roasted were greater than in FFSB, but lower when compared to SBC and SBM_Austria (p < .05). The SID of CP and all AA (except glutamic acid) were not different between SBC and SBM_Austria, but the SID of CP and all AA (except methionine) were greater (p < .05) in SBC than in SBM_GMO‐free. Furthermore, the SID of CP and most AA showed a quadratic response with decreasing TIA, and there exists a quadratic response in SID of CP and all AA with increasing lysine to CP ratio and neutral detergent insoluble nitrogen (p < .05). In conclusion, variation in chemical composition and SID of CP and AA was observed in different European soya bean and rapeseed products as influenced by differences in processing conditions. European SBC and SBM_Austria can be used as alternative to imported SBM_GMO‐free and SBM_Std in diets for growing pigs.     

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.     

饲粮蛋白源对早期断奶仔猪生产性能的影响

试验选用64头25日龄杜×(大×长)三元杂交断奶仔猪,随机分为4组:A、B、C为试验组,分别用猪肠膜蛋白粉(DPS)、大豆浓缩蛋白(SPC)、喷雾干燥猪血浆蛋白粉(SDPP)部分取代基础饲粮的鱼粉;D为对照组,饲喂基础饲粮(玉米-豆粕-鱼粉)。试验从仔猪25日龄断奶开始,70日龄结束。结果显示:试验组日增重均显著高于对照组,其中B组比对照组高13.18%(P<0.05);A组、C组分别比对照组高11.53%(P<0.05)、4.43%(P<0.05);B组和A组日增重差异不显著(P>0.05),但均显著高于C组,分别高8.38%(P<0.05)、6.80%(P<0.05)。B组日采食量比对照组高4.82%(P<0.05),A组、C组与对照组相比,日采食量有提高的趋势,但差异不显著(P>0.05)。A组、B组与对照组相比,料肉比有降低的趋势(P>0.05)。由此可见,本试验条件下,大豆浓缩蛋白、猪肠膜蛋白粉、猪血浆蛋白粉对早期(25日龄)断奶仔猪的饲喂效果均优于鱼粉,且大豆浓缩蛋白、猪肠膜蛋白粉对仔猪日增重的改善幅度大于喷雾干燥猪血浆蛋白粉(P<0.05)。     

Free versus microencapsulated organic acids in medicated or not medicated diet for piglets

Aim of the study was to investigate the growth performance of weaned piglets fed either a medicated or not medicated diet supplemented with either a blend of formic and lactic (64/36) acids (FL, 11 kg/ton) or a microencapsulated blend of organic acids and flavors (T) (1 kg/ton, Tetracid®S, EU patent 1391155B1,Vetagro srl, Italy). 480 three-week old SCAAPAG × Goland piglets were fed four diets (4 pens of 30 piglets per diet): FL or T with or without the medication (M) comprising colistin 180 ppm + amoxicillin 600 ppm for the 1st phase and chlortetracycline 1000 ppm + sulphadiazine 1250 ppm + trimetoprim 250 ppm for the 2nd phase. The piglets received a two-phase diet (I:18% CP, 1.3% Lys, 7.5% CF and 2600 kcal/kg NE; II:18% CP, 1.2% Lys, 5.6% CF and 2400 kcal/kg NE). All data were analysed by ANOVA. After 49 days, animals fed the medicated diets had higher feed intake (+ 24.5% for group FL + M vs FL − M and + 22.3% for group T + M vs T − M; P < 0.01) and lower mortality (overall 1.2% for the medicated diets fed animals vs 9.2% for the non-medicated ones). Final weights were: 26.8 ± 1.0 kg, 25.7 ± 0.8 kg for FL + M, T + M, 20.9 ± 0.7 kg, 21.6 ± 0.8 kg for FL − M and T − M, respectively (P < 0.05). The medication resulted in maintaining animals in good health status. The microencapsulation technique allowed to lower the acids dose to be included in the feed by ten fold at least maintaining the same effects that a high dose can give without medication.     

Effect of excess levels of lysine and leucine in wheat‐based,amino acid‐fortified diets on the mRNA expression of two selected cationic amino acid transporters in pigs

An experiment was conducted to evaluate the effect of excess levels of Leu and Lys on the expression of b^0,+ and CAT‐1 mRNA in jejunum, liver and the muscles Longissimus dorsi (LDM) and Semitendinosus (STM). Twenty pigs with an average initial BW of 16.4 ± 1.7 kg were used in a Randomized Complete Block. Dietary treatments (T) were as follows: T1, basal diet; T2, basal plus 3.5 g l ‐Lys/kg diet; T3, basal plus 1.5 g l ‐Leu/kg diet; T4, basal plus 3.5 g l ‐Lys plus 1.5 g l ‐Leu/kg diet. Diets in T1 and T3 met 100% the requirement of Lys for pigs within the 10 to 20 kg body weight range; diets in T2 and T4 contained 35% excess of Lys. Also, diets in T1 and T2 supplied 104%, whereas diets in T3 and T4 supplied 116% the requirement of Leu. The expression of b^0,+ in jejunum was reduced (p = 0.002) because of the supplementation of l ‐Leu, but l ‐Lys supplementation had no effect (p = 0.738). In contrast, the expression of b^0,+ in STM (p = 0.012) and liver (p = 0.095) was reduced by the high level of Lys, but Leu had no effect (p > 0.100). CAT‐1 expression in STM increased by high Lys (p = 0.023) and Leu (p = 0.007) levels. In liver, the expression of CAT‐1 substantially increased (p = 0.001) because of Lys. In conclusion, excess levels of dietary Lys and Leu affect the expression of cationic amino acid transporters, and this effect varies depending on the studied tissue.     

Effect of organic acids in drinking water during the last 2 weeks prior to slaughter on Salmonella shedding by slaughter pigs and contamination of carcasses

In this study, we investigated the effect of adding organic acids to the drinking water of finishing pigs 2 weeks prior to slaughter on the shedding and prevalence rate of Salmonella at slaughter. Approximately 600 animals from four Belgian pig herds infected with Salmonella were included. At two herds, the study was conducted twice. Before the start of the study, overshoes were taken at the different herds. Two weeks prior to the expected slaughter date, the pigs were randomly divided into two groups (treatment and control group) each containing on average 50 animals within each herd. The treatment group received from this day onwards acidified drinking water (pH = 3.6-4.0), the control group received non-treated water (pH = 7.8-8.5). All other housing, feeding and management factors were identical in both groups. At the slaughterhouse, 10 pigs of each group (20 pigs for each group of study group 6) were randomly selected and sampled (blood, contents of ileum and rectum, mesenteric lymph nodes and carcass swabs). All samples were immediately transported to the laboratory and submitted to Salmonella isolation. Salmonella was isolated out of 11.9% (66/554) of the samples taken at the slaughterhouse, with the highest frequency found in the content of the ileum (18.7%), followed by 17.8% in the lymph nodes, 7.2% in the content of the rectum and 3.6% in the carcass swabs. The results did not reveal a significant difference between the treatment and control groups for the different slaughterhouse samples. The study documented that the investigated control strategy namely, the strategic application of organic acids during the last 2 weeks prior to slaughter was insufficient to decrease Salmonella shedding and contamination shortly before and during slaughter.     

Effect of arginine supplementation on the morphology and function of intestinal epithelia and serum concentrations of amino acids in pigs exposed to heat stress

The exposure of pigs to heat stress (HS) appears to damage their intestinal epithelia, affecting the absorption of amino acids (AAs). Arg is involved in the restoration of intestinal epithelial cells but HS reduces Arg intake. The effect of dietary supplementation with Arg on the morphology of intestinal epithelia, AA transporter gene expression, and serum concentration (SC) of free AAs in HS pigs was analyzed. Twenty pigs (25.3 ± 2.4 kg body weight) were randomly assigned to two dietary treatments: Control (0.81% Arg), wheat–soybean meal diet supplemented with l-Lys, l-Thr, dl-Met, and l-Trp, and the experimental diet where 0.16% free l-Arg was supplemented to a similar Control diet (+Arg). All pigs were individually housed and exposed to HS, fed ad libitum with full access to water. The ambient temperature (AT), recorded at 15-min intervals during the 21-d trial, ranged on average from 29.6 to 39.4 °C within the same day. Blood samples were collected on day 18 at 1600 hours (AT peak); serum was separated by centrifugation. At the end of the trial, five pigs per treatment were sacrificed to collect samples of mucosa scratched from each small intestine segment. The expression of AA transporters in intestinal mucosa and the SC of AAs were analyzed. Villi height (VH) was higher (P < 0.01) in the duodenum, jejunum, and ileum but the crypt depth did not differ between the Control and the +Arg pigs. Supplementation of l-Arg increased the mRNA coding for the synthesis of the cationic AA transporter b^0,+ (P < 0.01) and the neutral AA transporter B⁰ (P < 0.05) in the duodenum by approximately 5-fold and 3-fold, respectively, but no effect on mRNA abundance was observed in the jejunum and ileum. The supplementation of l-Arg increased serum Arg, His, Met, Thr, Trp, and urea (P < 0.05) and also tended to increase Val (P < 0.10) but did not affect Ile, Lys, Leu, and Phe. These results indicate that supplementing 0.16% l-Arg to the Control diet may help to improve the function of the small intestine epithelium, by increasing the VH, the abundance of AA transporters, and the SC of most indispensable AAs in pigs exposed to HS conditions. However, the lack of effect of supplemental Arg on both Lys SC and weight gain of pigs suggests that increasing the Lys content in the +Arg diet might be needed to improve the performance of HS pigs.