The influence of nutritional and management factors on piglet weight gain to weaning in a commercial herd in Denmark

The effects of weaning age, type of creep diet and the classification of piglets as ‘eaters’ or ‘non eaters’ of creep feed on weight gain to weaning were examined. Four antimicrobial-free diets were offered from day 14 of lactation: (i) wheat-soy based diet with animal and vegetable (‘mixed’) protein sources (COMM), (ii) heat-processed rice (HPR) with barley hulls and potato starch and mixed protein sources (RBPS), (iii) HPR with sugar-beet pulp and mixed protein sources (RSBP), and (iv) HPR with mixed protein sources (R). Pigs were weaned at an average of either 27 (early) or 33 (late) days of age. A dye (indigo carmine) was added to each diet at day 24 of lactation in both groups to classify piglets as ‘eaters’ or ‘non eaters’ of creep feed, based on appearance or non-appearance, respectively, of dye in faeces. Pigs weaned late weighed 1.4 kg more (P < 0.001). Weaning age interacted with diet type and eating classification for weaning weight (P < 0.001). Of the 1067 piglets where classification of the faecal dye was possible, 829 (77.7%) were ‘eaters’ and 238 (22.3%) were ‘non eaters’. This qualitative estimate of creep feed consumption did not influence weight gain to weaning (P > 0.05).     

The effects of direct fed microbials delivered through the feed and/or in a bolus at weaning on growth performance and gut health

Weanling pigs (n = 188) were used in a 5-wk experiment to determine the effects of a bolus of direct fed microbials (DFM) at weaning and/or feeding DFM on growth performance and gastrointestinal histology. Dietary treatments were: 1) basal negative control (NC), 2) Trt. 1 + DFM in a bolus at weaning, 3) Trt. 1 + DFM in the feed for d 1–34, 4) Trt. 1 + DFM in a bolus at weaning, and in the feed for d 1–34, and 5) Trt. 1 + in-feed antibiotics (carbadox, 55 ppm). Dietary antibiotics (Trt. 5) improved ADG (P < 0.05) during phase 2 (d 7–21) compared to pigs fed DFM (Trt. 3). A bolus dose of DFM at weaning, with or without subsequent DFM in the feed (Trt. 2 and 4), resulted in similar growth performance to pigs on Trt. 1 or 5. However, providing DFM in the feed alone (Trt. 4), resulted in a reduced ADG during phases 1 (d 1–7; P < 0.05) and 2 (d 7–21; P < 0.10) compared to pigs fed the antibiotic diet (Trt. 5). Overall ADFI was higher for pigs fed antibiotics (Trt. 5) compared to all other treatments, except pigs given a bolus dose of DFM at weaning and provided with DFM in the feed (Trt. 4). On d 34, duodenal villus height was higher (P < 0.05) for pigs fed the antibiotic diet (Trt. 5) compared to pigs receiving the bolus dose of DFM at weaning with no subsequent treatment (Trt. 2). Ileal crypt depths were greater (P < 0.05) for pigs on the positive control diet (Trt. 5) compared to all other treatments on d 7. Cellular proliferation rates in ileal crypts were increased (P < 0.05) on d 21 for pigs fed antibiotics (Trt. 5) compared to pigs fed the negative control diet (Trt. 1). On d 34, increased ileal crypt proliferation rates (P < 0.05) were observed in pigs receiving DFM through the feed (Trt. 4) only compared to pigs receiving the combination bolus and in-feed DFM (Trt. 5) and pigs fed the negative control diet (Trt. 1).     

Creep feed intake during lactation enhances net absorption in the small intestine after weaning

The aim of the study was to measure the effect of creep feeding during lactation on net absorption in the small intestine at 4 days after weaning. Intermittent suckling was used to increase creep feed intake during lactation. Creep feed containing chromic oxide was provided. Based on the colour of the faeces, piglets were classified as ‘eaters’ or ‘non-eaters’, respectively. At day 4 after weaning, an in vivo small intestine segment perfusion test was performed at 5 sites along the small intestine in 24 piglets (12 eaters and 12 non-eaters). At both sides of each intestinal segment a tube was fitted to perfuse and drain fluid in order to assess net absorption. Net absorption was higher in eaters than in non-eaters (P < 0.001). Net absorption varied greatly between and within piglets and was highest in the caudal segments of the small intestine (P < 0.001). These data suggest that creep feeding could be a useful tool in the prevention of post-weaning diarrhoea.     

Microbial diversity in the large intestine of pigs born and reared in different environments

Pigs born outdoors and reared on deep litter (straw) have been reported to experience less of a growth check after weaning and have a higher dressing percentage than counterparts born and reared under conventional (indoor) systems. The reason(s) for this difference is/are presently unknown, but differences in the gut environment might contribute to these observations. PCR-DGGE techniques were used in this study to examine microbial diversity and banding patterns in the large intestine of piglets that were reared under different rearing conditions. Six piglets per treatment were euthanised at weaning (21 days) and at 7 days and 21 days after weaning from two extreme treatments [indoor-born: conventionally-raised after weaning (‘Indoor’) or outdoor-born, deep-litter raised after weaning (‘Outdoor’)]. The Shannon diversity index was calculated, and multivariate analysis of banding patterns was performed. Indoor pigs had a more diverse bacterial population at weaning and 21 days after weaning than Outdoor pigs. However at the end of the first week after weaning, outdoor-born and deep-litter pigs had a more diverse microbiota. The Shannon diversity index continued to increase with time after weaning in Outdoor pigs, which did not occur in Indoor pigs. Multivariate analysis of banding patterns showed there was a trend (P = 0.109) for a difference in microbial structure depending on housing type. There was also a significant (P < 0.001) effect of sampling time after weaning and a significant interaction (P < 0.001) between housing and time after weaning.     

Effects of low-protein diets supplemented with crystalline amino acids on performance and intestinal development in piglets over the first 2 weeks after weaning

This study was conducted to determine the effects of low-protein diets supplemented with crystalline amino acids (AA) on performance and intestinal development in barrows (n = 32) over 2 weeks after weaning at 18 ± 1 day. Four maize-soybean meal based diets providing 0.93 g standardized ileal digestible lysine/MJ ME were prepared. The treatments were a control diet containing 23.1% CP (crude protein) and three low-protein diets (21.2, 18.9, and 17.2% CP, respectively), which were supplemented with crystalline AA to achieve an ideal AA pattern. Piglets were raised individually and had free access to feed and water. Average daily gain (ADG) and average daily feed intake (ADFI) were measured weekly. Severity of diarrhea was monitored twice per day. Blood from all piglets was taken for determining serum urea nitrogen on d 0, 7, and 14 and serum free AA concentration on d 14. At the end of the experiment, all piglets were killed to measure morphology of the small intestine and disaccharidase activities. Reducing CP level did not affect ADFI (P > 0.10) but resulted in poorer (linear, P < 0.05; quadratic, P < 0.05) ADG and feed:gain ratio (F:G) over the 2-week study period. However, most of the effect of dietary CP was due to the significant deterioration of performance with the 17.2% CP diet. Faecal consistency was improved linearly (P < 0.01) with dietary CP decrease. Reducing dietary CP from 23.1 to 17.2% resulted in a linear (P < 0.001) and quadratic (P < 0.001) decrease in serum urea nitrogen levels on d 7 and 14. Serum arginine (P < 0.001), glutamine (P < 0.05), and proline (P < 0.05) concentrations were decreased in pigs fed the 17.2% CP diet compared with those fed the control diet on d 14. Villous height was decreased (P < 0.05) in the duodenum and jejunum by the reduction of dietary CP. As dietary CP declined, lactase and sucrase activities were reduced (P < 0.01) in the proximal jejunum. In conclusion, reducing CP concentration from 23.1 to 17.2% led to decreased growth performance associated with morphological changes of the gut and reduced disaccharidase activities in the small intestine. But reducing dietary CP from 23.1 to 18.9% did not affect intestinal morphology and disaccharidase activities.     

Effect of early weaning on performance, carcass and meat quality of spring-born bull calves raised in dry mountain areas

Sixteen bull calves were born in the Spanish Central Pyrenees in spring. They were either early (EW, 90 days of age) or normal weaned (NW, 180 days of age). At day 90, EW calves were placed on an intensive diet while NW calves were turned out with their dams to high mountain pastures. After summer, at day 180, NW calves were weaned and placed with EW calves on a common finishing diet until slaughter at the fixed age of 1 year. From birth to early weaning date, no performance differences appeared. However, EW calves gained faster (1.549 kg/day) than their unweaned counterparts (0.783 kg/day) from early to normal weaning date (P < 0.001). During the finishing period, NW calves showed compensatory growth, with a 44% higher ADG than EW calves (P < 0.001), with a similar feed intake and a better feed conversion ratio. Early weaned calves had a longer fattening phase than NW calves (264 vs. 158 days, respectively; P < 0.001) and thus total feed intake and feed costs were greater. When slaughtered at 1 year of age, EW and NW calves attained similar weight (489 vs. 510 kg, respectively; P > 0.05), but dressing percentage was higher for EW calves (56.9%) than for NW calves (55.2%) (P < 0.01), which led EW calves to have heavier carcasses, without differences in fat score or conformation. The different growth paths, the result of weaning management, did not affect meat tenderness, chemical composition and fatty acid profile, but affected meat lightness, with higher values for compensating calves (NW) than calves in continuous growth (EW). In conclusion, advancing weaning age modified calf performance without affecting substantially carcass characteristics, except for an improvement in dressing percentage, or meat quality.     

Resistant starch for weaning pigs — Effect on concentration of short chain fatty acids in digesta and intestinal morphology

We investigated the effect of potato starch, a source of resistant starch (RS), in diets for newly weaned pigs on production of short chain fatty acids (SCFA) and intestinal morphology. At weaning, at 4 weeks of age, 24 pigs were divided into 3 groups and fed diets containing 0 (C), 80 (P80) or 160 (P160) g raw potato starch per kg feed for 12 days. Pigs fed P160 had the longest villi whereas pigs fed P80 had the deepest crypts. Villous height at the mid-small intestine and average daily gain were positively correlated (r = 0.59, P < 0.01). The daily gain tended to be lower (P = 0.08) for pigs fed P80 than for pigs fed C or P160. The colon weight increased in pigs fed RS which coincided with an increased crypt depth in the colon. The concentration of SCFA increased in the large intestine with increasing amount of RS. The proportion of acetic acid decreased and the proportion of butyric acid increased in pigs fed P80 and P160. The increased SCFA production, especially of butyrate, may explain the colonic growth.     

Association between butyrate and short-chain fatty acid concentrations in gut contents and faeces in weaning piglets

The concentration and composition of short-chain fatty acids (SCFA) in gastrointestinal and faecal samples were studied in weaning pigs fed different amounts and composition dietary fibre (DF). In Trial 1 a total of 50 castrated piglets were fed five experimental diets with varying contents of citrus pectin (soluble fibre) and barley hulls (insoluble fibre) and gastrointestinal contents were collected at euthanasia 9 days after weaning. In Trial 2, 120 pair-wise penned piglets were allocated to the same experimental diets as in Trial 1 (24 piglets per treatment), and fresh faecal samples were collected 5 and 32 days after weaning.

There was no difference in the concentrations of SCFA caused by dietary treatments, but across treatments there was a correlation between concentration of SCFA and the proportion of butyrate. The correlation was lowest in the caecum (r² = 0.22, P = 0.0007) and highest in the distal colon (r² = 0.45, P = 0.0001). In faeces there was no relationship 5 days after weaning (r² = 0.004. P = 0.64) but a correlation of r² = 0.25 (P = 0.0001) 32 days after weaning. The results suggest that adaptive changes and differences between piglets in fermentative capacity immediately after weaning are associated not only with a higher concentration of SCFA but also a changed fermentation profile.     

Effect of rearing environment and age on gut development of piglets at weaning

Outdoor reared pigs are reported to be larger at weaning than indoor reared pigs and respond better to the weaning process. This may be due to enhanced gut development associated with increased size. Eighty sows were allocated to either indoor or outdoor farrowing on the basis of size, parity and past performance. Resulting litters were weaned at either 4 or 6 weeks of age. On days 26 and 40 of age, 40 (10/treatment) and 20 piglets (10/treatment still unweaned) were killed to measure intestinal morphology. Data were analysed as a 2 × 2 factorial using the GLM procedures of Minitab 12.2. Pigs reared outdoors were larger than those reared indoors at both weaning ages, pigs weaned at 6 weeks were heavier than those weaned at 4 weeks, 8.4 versus 7.4 kg at 4 weeks and 12.9 versus 10.5 kg at 6 weeks respectively (± 0.25, P ≤ 0.001). There were no differences in small intestine size relative to body weight due to rearing environment and no differences in gut morphology. When corrected for body weight, 6 week pigs had heavier small intestines than 4 week pigs, 0.39 (± 0.010) versus 0.34 (± 0.007) g/cm length, respectively (P ≤ 0.001). Six week unweaned pigs had similar villus heights to 4 week unweaned pigs but wider villi (P < 0.05) and deeper crypts, for example, at the 25% site crypt depths were 236 and 193 μm (± 7.7/5.5) respectively (P < 0.001). Hence increased piglet size due to outdoor rearing did not advance gut maturation whereas increased piglet size due to age did influence maturation of gut structure.     

The effect of dietary crude protein concentration and inulin supplementation on nitrogen excretion and intestinal microflora from finisher pigs

A 2 × 2 factorial experiment was used to investigate the interaction between dietary crude protein (CP) concentration (200 vs 140 g/kg) and inulin supplementation (0 vs 12.5 g/kg) on nitrogen (N) excretion and intestinal microflora from 16 boars (n = 4, 74.0 kg live weight). The diets were formulated to contain similar concentrations of digestible energy and lysine. Pigs offered the high CP diets had a higher excretion of urinary N (P < 0.01), faecal N (P < 0.01) and total N (P < 0.001) than the pigs offered the low CP diets. Inulin supplementation increased faecal N excretion (P < 0.05) and decreased urine: faeces N ratio (P < 0.05) compared to the inulin free diets. There was no significant effect (P > 0.05) of dietary treatment on N retention. There was an interaction (P < 0.05) between dietary CP concentration and inulin supplementation on caecal E.coli. Pigs offered the diet containing 200 g/kg CP plus inulin decreased the population of E.coli compared to the inulin supplemented 140 g/kg protein diet. However, CP concentration had no significant effect on the population of E.coli in the unsupplemented diets. Inulin supplementation increased caecal bifidobacteria (P < 0.01) compared to the inulin free diets. In conclusion, inulin supplementation favourably altered N excretion and lowered the population of E.coli at high CP concentrations.     

A diet moderately deficient in zinc induces limited intestinal alterations in weaned pigs

The aim of this work was to test the hypothesis that a moderate zinc deficiency induces intestinal alterations in weaned piglets. A diet based on maize and soybean meal was formulated without supplemental zinc (33 ppm, zinc-deficient) or with added zinc (113 ppm, control). These diets were pair-fed for 18 or 27 d to intra-litter pairs of piglets weaned at 21 d of age. The feed intake and growth, plasma concentrations of zinc and alkaline phosphatase (ALP) activity, and morphometry, enzyme activities and the microflora of the mid-jejunum were investigated. Feed intake and growth were similar between diets and diarrhoea was not observed. By contrast, plasma zinc and ALP activity were much lower in zinc-deficient piglets at slaughter (P < 0.001). The weight of organs was unaffected, except colonic tissue that was lighter in piglets fed the zinc-deficient diet (P < 0.05). Neither villus-crypt intestinal architecture nor mucosal enzyme activities were altered. Jejunal counts of lactic acid bacteria and coliforms tended to be higher in the zinc-deficient pigs (P ≤ 0.10). In conclusion, feeding a diet moderately deficient in zinc for 18–27 d induced limited intestinal alterations in weaned pigs.     

Growth performance and nitrogen metabolism in weaned pigs fed diets containing different sources of starch

This study was conducted to determine the performance and N metabolism in weaned pigs fed diets containing different sources of starch. Pigs were weaned at 28 days of age, and assigned randomly into 4 soybean meal-based diets containing different sources of starch: corn, brown rice, sticky rice, and Hi-Maize 1043 (resistant starch). There were 12 pigs per treatment group in the growth-performance trial. Additionally, a 4 × 4 Latin design was used for a nitrogen (N) balance study, with 5 days for each experimental period (n = 4). Average daily gains were 0.38, 0.34, 0.31, and 0.28 kg/day (P < 0.01), respectively, for pigs fed the corn, brown rice, sticky-rice, and Hi-Maize 1043 diets. Feed:gain ratios were 1.65, 1.78, 1.95, and 1.86 (P < 0.01), for the above 4 diets, respectively. Fecal N and urinary N excretion as well as the apparent fecal digestibility of crude protein in pigs fed the corn, brown rice, and sticky-rice diets were higher (P < 0.01) compared with pigs fed the Hi-Maize 1043 diet. Collectively, our results indicate that dietary sources of starch affected both growth performance and N utilization in weaned pigs.     

Effects of pre- and postnatal exposure to garlic and aniseed flavour on pre- and postweaning feed intake in pigs

The low nutrient intake shortly after weaning is a major cause of post-weaning problems. Feed intake after weaning is strongly related to feed intake during lactation. Feed intake during lactation, however, varies considerably between litters. We hypothesised that prenatal and postnatal exposure to certain flavours would increase the intake of feed containing the same flavours pre- and postweaning. Multiparous sows did (n = 17) or did not (n = 14) receive 50 g garlic granulate/powder and 25 g aniseed as daily additive to their diet during the last month of gestation and during lactation. From day 14 of lactation, litters were submitted to intermittent suckling: 12 h separation form the sow each day. During lactation, all litters had 40 g garlic and 20 g aniseed per kg added to their creep feed. After weaning, half of the litters had no additive in their diet. Piglets were weaned at 4 weeks (13 litters) or at 6 weeks (18 litters). At 6 weeks of lactation, litters of which the dam received the flavour in her diet, had a higher feed intake (309 ± 43 vs 233 ± 35 g/p/d) than litters of dams without the flavour, although the difference was not significant. Sow diet had no effect on postweaning feed intake, but postweaning piglet diet did. Late (week 6) weaned litters receiving the flavoured feed had a higher feed intake from 3 to 10 days after weaning (833 ± 38 vs 687 ± 58 g/p/d). Weight gain during the first 10 days after weaning was not affected by sow or pig diets. Feed intake and weight gain shortly after weaning were strongly related to feed intake during lactation (overall R = 0.64, P < 0.05 and R = 0.77, P < 0.05). We conclude that early experience with flavours increases later acceptance and improves adaptation to post weaning conditions.     

Intermittent suckling improves post-weaning feed uptake but does not change functional gut characteristics of piglets

Suckling pigs were separated from their dam for 24 h on day 21 (1 × 24 h fasting, n = 10) or day 21 and 24 (2 × 24 h fasting, n = 10). Pigs in the control group (n = 10) were not fasted before weaning. All pigs were weaned on day 28 postpartum. Feed intake during the first 4 days post-weaning was higher (P < 0.05) for pigs exposed to 1 × 24 h fasting compared with controls. Water consumption was not affected by fasting prior to weaning. The difference in post-weaning feed uptake was not reflected in any clinical traits, intestinal morphology, or activity of digestive enzymes (maltase, dipeptidylpeptidase IV, aminopeptidases A and N; P > 0.15). In conclusion, a short period of fasting prior to weaning can increase post-weaning feed uptake, although this had no clinical impact under the present experimental conditions.     

Influences of lipopolysaccharide-induced immune challenge on performance and whole-body protein turnover in weanling pigs

The objective of this study is to characterize the influence of immune stress induced by lipopolysaccharide (LPS) on protein utilization and turnover for early-weaned pigs. A total of 15, crossbred weanling pigs (initial body weight 10.15 ± 0.39 kg) were assigned to one of three treatments. Pigs were injected with LPS and fed ad libitum (LPS-challenge), or injected with endotoxin-free physiological salt solution (PSS) and fed ad libitum (control), or injected with PSS and fed the same amount of feed as LPS-challenged pigs (pair-feed). All pigs received a 4-d nitrogen balance trial. On d 1 and 3 of the trial, LPS-challenged pigs were injected intramuscularly with 200 μg/kg BW of LPS dissolved in 1 ml PSS. Pigs in other treatments were injected with 1 ml PSS. ¹⁵N-Glycine (5 mg/kg BW) was gastrically infused after the second injection. Feces and urine were collected daily to determine the N output throughout the duration of the trial. Lymphocyte blastogenesis (LB) and serum immunoglobulins (IgA, IgG, IgM) were also detected to illustrate the LPS-induced immune responses. Results indicated that the injection of LPS significantly (P < 0.01) elevated the LB and resulted in lower average daily gain (ADG), feed intake (ADFI) and efficiency of feed utilization than control pigs. Pair-fed pigs had higher performance than LPS-challenged pig but poorer than control pigs. Injection of LPS also resulted in significantly (P < 0.01) lower nitrogen intake and efficiency of utilization than controls, and more fecal N excretion than Pair-fed pigs (3.19 ± 0.85 vs. 2.19 ± 0.67 g/d, P < 0.05). The whole-body nitrogen flux (4.34 ± 0.19 vs. 11.35 ± 0.12 g N/kg BW^0.75/d) and N accretion (5.57 ± 0.59 vs. 10.17 ± 1.12 g Pr/kg BW^0.75/d) were acutely (P < 0.01) reduced as the feed intake decreased, but there was no significant difference between LPS-challenged and pair-fed pigs. Injection of LPS markedly (P < 0.05) increased the protein degradation (16.76 ± 1.09 vs. 14.53 ± 1.24 g N/kg BW^0.75/d). It is concluded that LPS-induced immune challenge depresses growth performance and feed utilization efficiency by enhancing protein degradation rate and decreasing protein utilization for body protein retention.     

Effect of coarse ground corn, sugar beet pulp and wheat bran on the voluntary intake and physicochemical characteristics of digesta of growing pigs

The aim of this work was to evaluate the influence of a coarse ground cereal and two fibrous ingredients incorporated in the diet on the physicochemical properties of digesta and productive parameters of pigs during the first stage of the growing period. A total of 96 pigs (initial body weight, BW, 15 kg) were distributed into four experimental treatments: the control diet (CT) consisted of corn, barley and soybean meal milled to pass through a 2.5 mm screen; the coarse corn diet (CC) was prepared by milling the corn to a coarser particle size (4.0 mm screen); the sugar beet pulp diet (SBP) and the wheat bran diet (WB) were prepared by replacing some of the corn for sugar beet pulp (80 g/kg) or wheat bran (100 g/kg) respectively, in order to contain a higher amount of non-starch polysaccharides (NSP). Three experimental periods were considered (7, 21 and 42 days) during which body weight (BW) and voluntary feed intake were assessed. At the end of each period eight animals per diet were slaughtered. Weight of the gastrointestinal tract and its compartments (full and empty) was recorded and the contents were sampled. Digesta samples were analysed for water concentration, water retention capacity (WRC), ammonia and short-chain fatty acids concentration (SCFA). Histological study of the proximal colon tissues was also performed. In general, the different parameters evaluated showed differences between the experimental periods, but few interactions were recorded. Animals fed CC, SBP and WB diets presented a lower feed intake (P ≤ 0.009) compared to CT fed animals. Compared to the control diet, coarse grinding of corn provoked an increase in the colonic digesta content (P = 0.032). Similarly, animals fed the SBP diet compared to CT animals, showed an increase in the contents (P = 0.009) of hindgut, and in the concentration of water in the digesta (P ≤ 0.011). Compared to CT diet the SBP diet lowered the ammonia concentration in the hindgut contents (P ≤ 0.045) and increased the concentration of SCFA in the distal colon (P ≤ 0.025). Animals fed the SBP diet also showed a lower number of lymphoid nodes in the colonic mucosa compared to the other diets (P ≤ 0.043). Minor modifications were observed associated with the incorporation of wheat bran in the diet, but colonic water from WB fed animals showed a tendency to increase cytolytic capacity. The results confirm major changes in the voluntary intake and physicochemical properties of digesta as affected by the incorporation in the diet of a fibrous ingredient or coarse grinding of cereals.     

Dietary protein and fermentable carbohydrates contents influence growth performance and intestinal characteristics in newly weaned pigs

Increasing the dietary amount of fermentable carbohydrates (FC) may counteract the negative effects of protein fermentation in newly weaned piglets. To study this hypothesis, 272 newly weaned piglets were allotted to 4 dietary treatments in a 2 × 2 factorial arrangement with low and high FC (7.5 and 13.5%) and crude protein (CP, 15 and 22%) content as respective factors. Intestinal histology, enzyme activity, microbiota and fermentation products were determined in 8 pigs per treatment 7 days post-weaning.

In the 4 wk experimental period, interactions between dietary CP and FC content were found for feed intake (P = 0.022), daily gain (P = 0.001), and gain:feed (P = 0.033). The high-FC content reduced daily gain by 50 g/d in the low-CP diet, whereas the FC content did not affect growth performance in the high-CP diet. Over the 4 wk experimental period, daily gain (350 g/d) and feed intake (519 g/d) were highest for piglets on the low-CP low-FC diet. The high-FC content resulted in an increase in number of lactobacilli (P = 0.047) and a decrease of total coliforms (P = 0.06) in the small intestine. It increased the lactic acid content (P = 0.08) and reduced the ammonia content (P = 0.04) in the small intestine and increased the VFA content in the colon (P = 0.009). The reduction in CP content reduced ammonia concentration in the small intestine (P = 0.003). We concluded that dietary FC influenced microbial population and fermentation products in the gut. However, this was not reflected in an increased growth performance.     

The effect of dietary protein supply on carcass composition, size of organs, muscle properties and meat quality of pigs

This study investigated the effect of dietary protein supply on growth performance, carcass composition and size of organs in pigs slaughtered at the age of 165 ± 2 d. In addition, we analysed muscle fibre properties and glycolytic potential of light muscles longissimus lumborum (LD), semimembranosus (SM), and gluteus superficialis (GS), and dark muscles infraspinatus (IS) and masseter (M) of 20 gilts and 20 barrows. Of these pigs, 16 were Finnish Landrace, 16 were Finnish Yorkshire, and 8 were crosses of these breeds. The pigs were fed low-or high-protein diets formulated to contain 6.0 and 9.5 g of apparent ileal digestible lysine/feed unit (1 fu = 9.3 MJ NE), respectively. The pigs were fed according to a restricted weight-based feeding scale (13–30 MJ NE/d). Lean meat, fat, bones, and skin of the carcasses as well as organs were dissected and weighed. The pH value was measured 45 min post mortem from LD, and 24 h post mortem from LD, SM and GS. Drip loss, lightness (L) and redness (a) were measured from LD, SM and GS. Pigs with a low-protein supply showed a lower growth rate (P < 0.01), carcass weight (P < 0.01), and carcass lean meat content (P < 0.01), but higher carcass fat content (P < 0.01) and smaller kidneys (P < 0.01) than did pigs with a high-protein supply. In LD, the differences in cross-sectional areas in all muscle fibre types (P < 0.05) between the feeding groups were significant; in GS we found significant differences in cross-sectional areas of type IIA and type IIB (P < 0.05), while in SM we found no differences in muscle fibre cross-sectional areas between the feeding groups (P > 0.05). We found no such differences in the dark muscles studied. We also took into account the effect of both the breed and sex on the studied properties. The low-protein diet increased glycolytic potential in porcine LD and SM, and decreased the pH value measured 45 min post mortem from LD. The dietary protein supply affected no other meat quality traits studied. A more rapid drop in pH in LD resulted in a lighter and less red meat with higher drip loss.     

Effects of feeding linseed and linseed expeller meal to newly weaned piglets on growth performance and gut health and function

The effects were evaluated of the inclusion of full fat linseed (125 g/kg) (LS) or linseed expeller meal (85 g/kg) (LSM) in diets for weaned piglets on growth performance and parameters of gut health and function. The diets were fed to groups of 12 post weaning single housed piglets. Three of the five treatments (Control (C)+, LS+, LSM+) were challenged with an enterotoxigenic strain of E. coli on day 6. Two treatments were not challenged (C− and LS−). The main response criteria were daily feed intake, body weight gain, faecal shedding of the E. coli, faecal consistency score, faecal nutrient digestibility and gut wall morphology and histology of the jejunal mucosa on day 18/19 of the study. Over the total experimental period (day 0–18) feed intake and body weight gain were highest in treatment C− and lowest in treatment LSM+ (P < 0.05). Feed conversion ratio did not differ between treatments over the total experimental period. Over day 10–12 of the study, the faecal digestibility of dry matter, ash and energy was higher for treatments C− and C+ compared to treatments LS−, LS+ and LSM+ (P < 0.05). There was no significant difference in the faecal shedding of E. coli between treatments C+, LS+ and LSM+. Intestinal mucosal histology and morphology were only slightly affected by the dietary treatments. It was concluded that the use of full fat linseed or linseed expeller meal did not show to be functional ingredients in diets for post-weaning piglet in terms of supporting gut health.     

Dietary nucleotide supplementation reduces occurrence of diarrhoea in early weaned pigs

In the weaning period, transition from sow's milk to the post-weaning diet causes the withdrawal of important nutrients as milk nucleotides, which are known to be determinant for the development of the gastrointestinal tract and immune function. The objective of these investigations was to study the effect of including these nucleotides in solid diets for piglets. Nucleotide composition of sow's milk was analyzed using 5 sows at 21 days of lactation. The average free nucleotide concentration was 102.8 ± 9.16 μmol/100 mL. Two experiments were performed to assess the effect of a product based on this composition (Nucleoforce Piglets®) on digestive adaptation and incidence of diarrhoea of nursery piglets. In Exp. 1, three groups of 6 piglets were weaned at 21 days of age and fed with a diet supplemented with 0 (control), 1000 or 2000 ppm of nucleotides, and a fourth group of 6 piglets was maintained in lactation. Seven days after weaning, piglets were euthanized and samples of jejunal mucosa were processed for histological measurements. Villus height decreased from 448 μm in un-weaned pigs to 275 μm in the control group 7 days after weaning. Although there were no differences in feed intake among groups, the reduction in villous height was less pronounced (P < 0.001) in nucleotide supplemented groups showing a villous height of 351 and 378 μm with the doses of 1000 or 2000 ppm respectively. In Exp. 2, 384 early weaned pigs were fed during 14 days with a diet supplemented with 0 (control), 750 and 1000 ppm of nucleotides. ADG and ADFI were not modified by the treatment, but nucleotide supplementation reduced the number of pigs treated with antibiotic as a result of diarrhoea (15.63% vs 3.13% and 1.56%; for control, 750 and 1000 ppm; P < 0.001). These results suggest that dietary supplementation with nucleotides from yeast might help to prevent post-weaning diarrhoea in piglets.