Differential Impacts of Cereal and Protein Sources Fed to Pigs after Weaning on Diarrhoea and Faecal Shedding of Escherichia coli, Production, and Total Tract Apparent Digestibility.

Different cereal types, in combination with different protein sources, are fed to pigs after weaning, but their interactions and possible implications are not well researched. In this study, 84 male weaned piglets were used in a 21-day feeding trial to investigate the effects of feeding either medium-grain or long-grain extruded rice or wheat, in a factorial combination with protein sources of either vegetable or animal origin, on postweaning performance, shedding of ß-haemolytic Escherichia coli, and the coefficient of total tract apparent digestibility (CTTAD). Pigs fed either rice type performed the same (p > 0.05) as wheat-fed pigs after weaning. The use of vegetable protein sources reduced growth rate (p < 0.001) and feed intake (p = 0.007) and deteriorated the feed conversion ratio (p = 0.028) in weeks two and three compared to pigs fed animal protein sources. The number of antibiotic treatments given for clinical diarrhoea was similar (p > 0.05). However, the faecal E. coli score showed a trend for the main effect of protein source, with pigs fed animal proteins showing a higher E. coli score than pigs fed vegetable proteins (0.63 vs. 0.43, p = 0.057). There was also a tendency for an interaction (p = 0.069) between cereal type and protein source (p = 0.069), with this difference being associated with a greater faecal score in pigs fed diets with long-grain rice plus animal proteins and wheat plus animal proteins. Significant interactions occurred for the CTTAD when assessed in week three. In general, pigs fed diets with medium-grain rice or long-grain rice with animal proteins had a higher (p < 0.001) CTTAD for dietary components than pigs fed all other diets, and vegetable proteins depressed (p < 0.001) CTTAD compared to animal proteins (main effect of protein: p < 0.001). In summary, pigs tolerated the extruded rice-based diets well and performed equivalently to pigs fed wheat as the sole cereal, and the use of vegetable proteins decreased the E. coli score.

Dietary stimulation of the endogenous somatotropic axis in weaner and grower-finisher pigs using medium chain triglycerides and cysteamine hydrochloride.

BACKGROUND: Three experiments were conducted to examine the overall hypothesis that addition of medium chain triglycerides (MCT) and cysteamine hydrochloride (CSH) into the diets of young and growing pigs would stimulate the endogenous somatotropic axis to improve growth and performance. RESULTS: In Experiment 1, weaner pigs were given either a 5 d dietary supplement of 5 % MCT (n = 8) or a control diet (n = 8). MCT increased the plasma concentration of growth hormone (GH; P < 0.05) and the GH secretagogue, ghrelin (P < 0.05). Additionally, the MCT treatment reduced scouring (P < 0.05), maintained villous height in the small intestine (P < 0.05) and stabilised daily weight gain (P < 0.05), compared to the controls. Experiment 2 compared the effects of 4 levels (0, 1, 3 and 6 % v/v) of MCT supplementation in grower-finisher male pigs, of approximately 35 kg live weight (n = 15 per treatment). Blood samples taken after 7 wk of treatment showed that the MCT supplementation increased circulating ghrelin (P < 0.001), GH (P < 0.01) and insulin (P < 0.05) concentrations in a dose-dependent manner. Daily weight gain, feed intake and feed conversion ratio were not affected by the MCT diets. In Experiment 3, 64 female pigs of approximately 60 kg live weight were allocated to one of three dietary treatments: control (n = 20); 6 % MCT (n = 21); and 70 mg/kg CSH (n = 21). After 3 wk of supplementation, the MCT treated pigs had a higher plasma concentration of ghrelin compared to the control and CSH pigs (P < 0.05). Plasma concentrations of GH and weight were not affected by any of the dietary treatments. CONCLUSIONS: Evidence is provided in Experiment 1 to support the use of dietary MCT supplements, perhaps acting via stimulation of somatotropic endocrine pathways, to minimise weaning-associated disorders such as slowing of growth and diarrhoea. In Experiments 2 and 3, although there was no effect on weight gain or feed conversion ratio in either experiment, MCT and CSH increased endocrine components of the somatotropic axis.

Acetylsalicylic acid supplementation improves protein utilization efficiency while vitamin E supplementation reduces markers of the inflammatory response in weaned pigs challenged with enterotoxigenic E. coli.

BACKGROUND: This experiment was conducted to test the hypothesis that vitamin E (Vit E) and acetylsalicylic acid (ASA), a cyclooxygenase-2 (COX-2) inhibitor, will additively reduce the production of the immunosuppressive molecule prostaglandin E2 (PGE2) and hence reduce inflammatory responses in weaner pigs experimentally infected with an enterotoxigenic strain of E. coli. METHODS: The experiment was conducted in a research facility with 192 individually-housed male weaner pigs (Landrace × Large White) weighing 6.6 ± 0.04 kg (mean ± SEM). The pigs were experimentally infected with an enterotoxigenic strain of E. coli and were allocated to a 2 × 3 factorial design with the respective factors being without and with 125 ppm ASA and three levels of Vit E supplementation (50, 100 or 200 IU/kg diet, dl-α-tocopheryl acetate). RESULTS: Acetylsalicylic acid supplementation improved average daily gain (P < 0.05) and tended to improve feed:gain ratio (P < 0.10) during the first 14 d after weaning. Acetylsalicylic acid supplementation also improved (P < 0.001) amino acid utilization efficiency (as assessed by plasma urea level) and tended to decrease (P < 0.10) PGE2 production in the liver without affecting small intestinal histology and tight junction protein mRNA expression in the jejunal epithelium. Vitamin E supplementation greater than 100 IU/kg diet sustained both the plasma Vit E concentration (P < 0.001) and plasma haptoglobin content (P < 0.001) after weaning. However, there was no additive effects of the combined supplementation of ASA and Vit E on performance, intestinal barrier function and inflammatory responses of weaned pigs. CONCLUSIONS: Although ASA and vitamin E improved amino acid utilization efficiency and reduced acute inflammatory responses, ASA and vitamin E did not additively reduce production of PGE2 and inflammatory responses in weaner pigs experimentally infected with an enterotoxigenic strain of E. coli.

Dietary Lecithin Supplementation Can Improve the Quality of the M. Longissimus thoracis.

Forty crossbred (Large White × Landrace × Duroc) female pigs (16.4 kg ± 0.94 kg) were used to investigate the effect of dietary lecithin supplementation on growth performance and pork quality. Pigs were randomly allocated to a commercial diet containing either 0, 3, 15 or 75 g lecithin/kg of feed during the grower and finisher growth phase. Pork from pigs consuming the diets containing 15 g and 75 g lecithin/kg had lower hardness ( P < 0.001) and chewiness ( P < 0.01) values compared to the controls. Dietary lecithin supplementation at 75 g/kg significantly increased ( P < 0.05) the linoleic acid and reduced ( P < 0.05) the myristic acid levels of pork compared to the control and the 3 g/kg and 15 g/kg lecithin supplemented treatments. Pigs fed the 75 g/kg lecithin supplemented diet had lower plasma cholesterol ( P < 0.05) at slaughter compared to pigs fed the control diet and the 3 g/kg and 15 g/kg lecithin supplemented treatments. These data indicate that dietary lecithin supplementation has the potential to improve the quality attributes of pork from female pigs.

Effect of increasing the dietary tryptophan to lysine ratio on plasma levels of tryptophan, kynurenine and urea and on production traits in weaner pigs experimentally infected with an enterotoxigenic strain of Escherichia coli.

This experiment examined if immune system stimulation of weaner pigs, initiated by inoculation an enterotoxigenic strain of Escherichia coli (ETEC), increased the requirement for dietary tryptophan (Trp), modulated the inflammatory response, altered plasma levels of Trp and its metabolite kynurenine (Kyn) and effected post-weaning diarrhoea. Individually housed pigs (n = 72) weaned at 21 d of age were allocated to one of six treatments (n = 12) according to a two by three factorial arrangement of (1) with or without ETEC infection and (2) three dietary ratios of standardised ileal digestible (SID) Trp to lysine (Lys) (SID Trp:Lys) of 0.16, 0.20 or 0.24, in a completely randomised block design. Pigs had ad libitum access to diets (per kg 14.13 MJ ME, 12.4 g SID Lys, 195 g crude protein) for 3 weeks after weaning. Pigs were infected with ETEC (O149:K98:K88) at 72, 96 and 120 h after weaning and then bled on day 3, 11 and 19. An increased dietary Trp:Lys ratio increased plasma Trp and Kyn (p < 0.001) without effect of infection. On day 3, pigs fed 0.24 SID Trp:Lys had lower levels of plasma urea than at 0.20 Trp:Lys (p = 0.047) and on day 11, plasma urea was lower at 0.20 than at 0.16 SID Trp:Lys (p = 0.007). Infection increased (p = 0.039) the diarrhoea index and deteriorated faecal consistency from day 4-10 (p < 0.05). Treatments did not affect haptoglobin and acid soluble glycoprotein levels or daily gain and feed intake. However, 0.24 SID Trp:Lys improved (p = 0.021) feed efficiency without an effect of infection. In conclusion, in the absence of dietary antibiotic growth promotants, increasing the dietary SID Trp:Lys ratio to 0.24 improved feed conversion ratio after weaning and increased plasma levels of Trp and Kyn regardless of infection with E. coli.

Decreasing dietary particle size of lupins increases apparent ileal amino acid digestibility and alters fermentation characteristics in the gastrointestinal tract of pigs.

Two experiments were conducted to examine the effects of lupin particle size on amino acid (AA) and energy digestibility and fermentation characteristics in pigs. Expt 1 examined the effects of lupin variety (cv. Tanjil and Mandelup) and lupin particle size (746, 888, 1099 and 1136 mum) on the total-tract apparent digestibility of dietary components in 63.5 (sd 7.28) kg pigs. While variety had no effect on total-tract apparent digestibility, decreasing particle size of lupins linearly increased total-tract apparent digestibility of crude protein of diets containing 350 g lupins per kg (P < 0.01). Expt 2 examined the effect of lupin particle size (567, 995, 1198, 1250 and 1304 mum) on digestion and fermentation characteristics in 29.8 (sd 2.9) kg pigs. Pigs were fed the respective diets ad libitum for the first 2 weeks and fed at three times maintenance energy level in the third week. Pigs were euthanised under sedation at 46.7 (sd 4.21) kg to collect digesta samples along the intestinal tract. Decreasing particle size increased apparent ileal and total-tract digestible N (P < 0.01) and the apparent and standardised ileal digestible AA content (P < 0.05- < 0.001) of lupins. Decreasing particle size of lupins linearly decreased the molar proportion of straight-chain volatile fatty acids (sum of acetic, propionic and butyric acids; VFAAPB), while branched-chain fatty acids (sum of valeric, caproic, isobutyric and isovaleric acids) were linearly increased (P < 0.001). The results demonstrated that particle size of lupins is a critical factor influencing nutrient, especially AA, utilisation efficiency and fermentation characteristics in the gastrointestinal tract of pigs.

Effect of dietary supplementation with inulin and/or benzoic acid on the incidence and severity of post-weaning diarrhoea in weaner pigs after experimental challenge with enterotoxigenic Escherichia coli.

The purpose of this study was to evaluate the effects of feeding pigs with inulin and/or benzoic acid on post-weaning diarrhoea (PWD), indices of fermentation in the gastrointestinal tract, and production in pigs experimentally infected with an enterotoxigenic strain of Escherichia coli (ETEC). Forty-eight entire male pigs (Large White×Landrace) aged 21 ± 3 days of age and weighing 4.97 ± 0.08 kg (mean ± SE) were used in a 2×2 factorial experiment, with the respective factors being inulin (0 versus 8%) and benzoic acid (0 vs. 0.5%). Feeding inulin-supplemented diets improved (p = 0.022) the faecal consistency (FC) and reduced (p = 0.001) the incidence of PWD; however, the use of benzoic acid had no effects on PWD or faecal ETEC shedding. Wet faeces (a higher FC score) were associated with increased faecal ETEC shedding (R(2) = 0.394, p = 0.001). Inulin reduced the total concentrations of short chain fatty acids (p = 0.029) in the proximal colon. The total concentration of lactic acid was increased by inulin in the caecum (p = 0.007) and proximal colon (p = 0.002). Feeding inulin or benzoic acid had no effects on production after weaning.

Effects of feeding low protein diets to piglets on plasma urea nitrogen, faecal ammonia nitrogen, the incidence of diarrhoea and performance after weaning.

This study evaluated the effects of feeding pigs low protein (LP) diets for different lengths of time after weaning on indices of protein fermentation, the incidence of postweaning diarrhoea (PWD), growth performance, and total-tract apparent digestibility. Sixty weaner pigs weighing 6.1 +/- 0.13 kg (mean +/- SEM) were used in a completely randomised design having five treatments: (i) a high protein diet (HP, 243 g/kg CP) fed for 14 d after weaning (HP14); (ii) a low protein diet (LP, 173 g CP/kg) fed for 5 d after weaning (LP5); (iii) LP diet fed for 7 d after weaning (LP7); (iv) LP diet fed for 10 d after weaning (LP10), and (v) LP diet fed for 14 d after weaning (LP14). All diets were supplemented with lysine, methionine, tryptophan and threonine, with all LP diets additionally fortified with crystalline isoleucine and valine to conform to a proposed ideal amino acid (AA) pattern. A second-stage diet (215 g CP/kg) was fed to pigs at the conclusion of each treatment. None of the diets contained antimicrobial compounds. Feeding a LP diet, regardless of duration of feeding, decreased plasma urea nitrogen (p < 0.001) and faecal ammonia-nitrogen (p < 0.001) contents. Feeding a LP diet, irrespective of feeding duration, decreased the incidence of PWD at day 8 after weaning (p = 0.044), and pigs fed diets LP7, LP010 and LP14 had firmer faeces (p = 0.030, p = 0.047 and p = 0.007, respectively) between days 10 and 12 after weaning. Treatments LP5, LP7, LP10 and LP14 did not reduce (p > 0.05) growth performance up to 106 days after weaning compared to pigs fed the HP diet. Total-tract apparent digestibility of dry matter, energy and crude protein were similar (p > 0.05) between treatments. Our data suggest that feeding a LP diet, supplemented with AA to conform to an ideal AA pattern, for 7-10 days after weaning can reduce PWD in pigs fed antibiotic-free diets without compromising production.

Addition of oat hulls to an extruded rice-based diet for weaner pigs ameliorates the incidence of diarrhoea and reduces indices of protein fermentation in the gastrointestinal tract.

An experiment was conducted to determine whether adding oat hulls to weaner pig diets based on extruded rice or unprocessed wheat influenced post-weaning diarrhoea (PWD) and protein fermentation in the large intestine. Ninety-six male piglets (5.16 (SEM 0.08) kg) were allocated to (i) extruded rice plus animal proteins (RAP); (ii) RAP with added oat hulls (20 g/kg); (iii) wheat plus animal proteins (WAP); (iv) WAP with added oat hulls (20 g/kg). Blood and faecal samples were collected on days 7 and 14 after weaning at about age 21 d. Pigs fed RAP had more PWD than pigs fed WAP (P < 0.05). Oat hull supplementation to diet RAP decreased the incidence of PWD (P < 0.05). The total-tract digestibility of DM, starch and energy was higher in rice-based diets than in wheat-based diets (P < 0.001); however, oat hulls decreased digestibility of DM and gross energy (P < 0.001). Pigs fed RAP had higher plasma creatinine concentrations (P < 0.01), which were positively correlated to cumulative beta-haemolytic Escherichia coli scores after weaning (R2 0.928; P = 0.015). Addition of oat hulls decreased plasma urea concentrations only in pigs fed RAP (interaction; P < 0.05). Pigs fed RAP had lower faecal total biogenic amine concentrations than pigs fed WAP (P < 0.001). Oat hull supplementation tended to decrease total biogenic amine concentrations (P = 0.103). These data indirectly suggest that a mostly insoluble dietary fibre source such as oat hulls can decrease PWD in dietary situations where there may be a misbalance of carbohydrate to protein entering the hindgut.

Piglet growth before and after weaning in relation to a qualitative estimate of solid (creep) feed intake during lactation: a pilot study.

The experimental objectives were to verify whether a qualitative measure of creep feed consumption using a dye was related to performance, and associate this with teat order. Indigo carmine (5 g/kg) was added to a starter diet between days 12 and 31 (weaning) of lactation. On days 19, 23, 27 and 31, faeces from each piglet were assessed for colouration. Each piglet was categorized as a 'good', 'moderate' or 'small/non' eater of feed. There were no differences in pre-weaning growth rate between categories. Piglets classed as 'good' or 'moderate' eaters in lactation grew fastest (p = 0.009) in the first three days after weaning, but between days 4 and 7, the highest growth rate occurred in 'moderate' eaters. 'Small/ non' eaters grew slower (p < 0.01) between weaning and 28 days after weaning. Piglets drinking milk from anterior teats were heavier at weaning (p < 0.001) and for the first 14 days after weaning (p = 0.104) compared to piglets sucking posterior teats. Data from this study demonstrated that creep feed intake of piglets could qualitatively be assessed using indigo carmine, and that this categorization was related to performance in the immediate post-weaning period.

Feeding different types of cooked white rice to piglets after weaning influences starch digestion, digesta and fermentation characteristics and the faecal shedding of beta-haemolytic Escherichia coli.

Forty-eight, 21-d-old pigs were used to examine the effects of different types of cooked white rice on starch digestion, digesta and fermentation characteristics, shedding of beta-haemolytic Escherichia coli and performance after weaning. Pigs received one of three rice-based diets: (i) medium-grain Amaroo (AM), (ii) long-grain Doongara (DOON), and (iii) waxy (WAXY). The remainder of the diet consisted predominantly of animal proteins. A fourth diet contained mainly wheat, barley and lupins (WBL). On days 1, 3, 7 and 9 after weaning, a faecal swab was taken for assessment of beta-haemolytic E. coli and faecal consistency. Apparent digestibility of starch measured in the ileum 14 d after weaning was highest (P = 0.004) in AM and WAXY and lowest, but the same (P>0.05), in DOON and WBL. Starch digestibility in the rectum was highest in all rice diets (P < 0.001). Digesta viscosity was highest in pigs fed WBL in both the ileum (P < 0.001) and caecum (P = 0.027). Pigs fed rice generally had lighter (P < 0.05) gastrointestinal organs than pigs fed WBL. Performance of pigs was similar for all treatments; however, pigs fed rice-based diets had a higher (P < 0.001) carcass percentage than pigs fed WBL. Pigs fed WBL produced more acid (P < 0.05) but had lower molar proportions of acetate (P < 0.05), isobutyrate (P < 0.01) and isovalerate (P < 0.001) and a higher molar proportion of butyrate (P < 0.01) in the large intestine than pigs fed rice. Shedding of E. coli was low; however, pigs fed AM and WBL shed less E. coli than pigs fed other diets.

Evaluation of large-intestinal parameters associated with dietary treatments designed to reduce the occurrence of swine dysentery.

Diets containing soluble NSP (sNSP) and resistant starch (RS) increase hindgut fermentation in pigs, which in turn increases the incidence of swine dysentery (SD) after infection with the intestinal spirochaete Brachyspira hyodysenteriae. In the present study pigs were fed diets based on either wheat or sorghum, fed either raw or treated by extrusion, and/or with the addition of dietary enzymes to reduce RS and/or sNSP content. The aim was to determine the effects of these treatments on pig performance, large intestinal fermentation and expression of SD. Weaned pigs (n 132) were fed experimental diets for 4 weeks, when half the pigs in each treatment group were euthanased and samples collected to assess the influence of the diet on hindgut fermentation. The remaining pigs then were infected with B. hyodysenteriae, and monitored for development of SD. In general, compared with pigs fed raw wheat, fermentation in all parts of the large intestine was reduced either by feeding raw sorghum-based diets, or by feeding diets that were extruded. The addition of enzymes that degrade RS or sNSP reduced fermentation only in the distal parts of the large intestine. The incidence of SD was lower in pigs fed sorghum-based diets, and some of the extruded diets, but none of the dietary treatments offered full protection against SD. Multiple regression analysis of the results from all three experiments showed that colonisation by spirochaetes was highly related to dietary sNSP concentrations, whilst development of SD was similarly influenced by RS content of the diet.