Development of equations to predict the influence of floor space on average daily gain,average daily feed intake and gain : feed ratio of finishing pigs

Floor space allowance for pigs has substantial effects on pig growth and welfare. Data from 30 papers examining the influence of floor space allowance on the growth of finishing pigs was used in a meta-analysis to develop alternative prediction equations for average daily gain (ADG), average daily feed intake (ADFI) and gain : feed ratio (G : F). Treatment means were compiled in a database that contained 30 papers for ADG and 28 papers for ADFI and G : F. The predictor variables evaluated were floor space (m²/pig), k (floor space/final BW^0.67), Initial BW, Final BW, feed space (pigs per feeder hole), water space (pigs per waterer), group size (pigs per pen), gender, floor type and study length (d). Multivariable general linear mixed model regression equations were used. Floor space treatments within each experiment were the observational and experimental unit. The optimum equations to predict ADG, ADFI and G : F were: ADG, g=337.57+(16 468×k)−(237 350×k²)−(3.1209×initial BW (kg))+(2.569×final BW (kg))+(71.6918×k×initial BW (kg)); ADFI, g=833.41+(24 785×k)−(388 998×k²)−(3.0027×initial BW (kg))+(11.246×final BW (kg))+(187.61×k×initial BW (kg)); G : F=predicted ADG/predicted ADFI. Overall, the meta-analysis indicates that BW is an important predictor of ADG and ADFI even after computing the constant coefficient k, which utilizes final BW in its calculation. This suggests including initial and final BW improves the prediction over using k as a predictor alone. In addition, the analysis also indicated that G : F of finishing pigs is influenced by floor space allowance, whereas individual studies have concluded variable results.     

A natural interomone 2-methyl-2-butenal stimulates feed intake and weight gain in weaned pigs

A novel approach to potentially improve pig growth and welfare is to supplement environments with biologically meaningful odors that are deficient. The post-weaning environment lacks maternal odors that may contribute to the often-observed post-weaning lag in growth and health challenges. A recently reported rabbit maternal pheromone (2-methyl-2-butenal (2M2B)) may act as an interomone in the pig. The objective of this study was to determine if providing a maternal pheromone/interomone during transport and the post-weaning environment may enhance pig performance. A total of 40 replicated pens were used in a factorial arrangement of two transport olfactory experiences (Control v. 2M2B), two nursery olfactory experiences (Control v. 2M2B) and two sexes (barrow v. gilt). Pig body weight, average daily gain (ADG), average daily feed intake (ADFI) and gain : feed ratio (G : F) were measured and calculated over a 28-day post-weaning period. Pig sex and application of 2M2B during transport had no effect on pig performance. However, pigs that had 2M2B applied to their feeder at weaning had 15% greater feed intake (0.74 v. 0.64±0.03 kg/day, P<0.01) and 12% greater ADG (0.27 v. 0.24 kg/day, P<0.05) than control pigs. G : F ratio was not different between treatments. The interomone 2M2B is a novel, safe molecule that can improve pig post-weaning performance. This report highlights a new area of study and a natural class of compounds that can improve pig performance and potentially improve pig welfare.     

Performance,rumen fermentation,blood minerals,leukocyte and antioxidant capacity of young Holstein calves receiving high-surface ZnO instead of common ZnO

ABSTRACT

This study was conducted to assess the effect of feeding high-surface ZnO instead of common ZnO on the performance, rumen fermentation, blood minerals, leukocytes and antioxidant capacity of pre- and post-weaning calves. Thirty male suckling Holstein calves were allotted to one of three experimental groups (10 replicates) in a completely randomised design. Calves received: (1) a low Zn diet without Zn supplementation (control diet), (2) a high Zn diet containing 50 mg supplementary Zn/kg dry matter (DM) as common ZnO or (3) a high Zn diet containing 50 mg supplementary Zn/kg DM as high-surface ZnO (nano-ZnO). The control diet contained a native Zn content of 35.5, 34.7 or 33.7 mg/kg DM for the age periods of 7 to 30, 31 to 70 and 71 to 100 d, respectively. Supplementation of the diet with Zn did not change the dry matter intake (DMI) of calves during d 7 to 30 but increased the ADG in this period (p < 0.05). During age periods of 31 to 70 and 71 to 100 d, DMI and ADG of the Zn supplemented calves were higher (p < 0.05) than the control animals. The nutrient digestibility and the concentration of rumen volatile fatty acids were positively affected (p < 0.05) and the rumen ammonia-N concentration decreased (p < 0.05) by dietary Zn supplementation. Furthermore, the incidence of diarrhoea and pneumonia was lower in calves receiving the Zn supplemented diets. Irrespective of ZnO source, the blood total antioxidant capacity, leukocyte and haematocrit levels significantly increased (p < 0.05) with the ZnO supplemented diets. The post-weaning DMI, nutrient digestibility and blood haematocrit levels were higher in calves receiving high-surface ZnO, compared to those supplemented with common ZnO. With inclusion of the Zn sources in pre- and post-weaning diets, the blood Zn concentration increased (p < 0.05), but the blood Cu, Fe, Ca, P and Mg levels remained unchanged. Regardless of source, dietary supplementation of young calves with ZnO improved the performance and decreased rumen ammonia-N and the incidence of diseases. Moreover, high-surface ZnO had advantages over common ZnO in increasing the post-weaning feed intake, digestibility and blood Zn concentration.     

Effects of dietary supplementation with freshwater microalgae on growth performance,nutrient digestibility and gut health in weaned piglets

In pigs, digestive disorders associated with weaning lead to antibiotic use to maintain intestinal health. Microalgae have been studied in humans and rodents for their beneficial effects on health. The nutritional value of microalgae in animal diets has been assessed, but results were not conclusive. Dietary supplementation with microalgae as an alternative to antibiotic use was studied in two trials (72 piglets with initial BW=9.1±1.1 kg in trial 1 and 24 piglets with initial BW=9.1±0.9 kg in trial 2). All piglets were weaned at 28 days of age and then housed in individual cages. Piglets were randomly allocated to one of the four diets during 2 weeks after weaning: a standard diet with no supplementation (NC) or the standard diet supplemented with 1% Spirulina (SP), with 1% Chlorella (CV), or with 0.2% of colistin as positive control (PC). Trial 1 was performed to determine the effect of microalgae supplementation from 28 to 42 days on performance and incidence of diarrhoea. Animals received then a standard diet from 42 to 56 days of age. Trial 2 was performed from 28 to 42 days of age to assess nutrient digestibility of the experimental diets and to determine inflammatory status and intestinal morphology at 42 days of age. In trial 1, 94% of the pigs had diarrhoea in the 1st week after weaning with no beneficial effect of colistin on diarrhoea incidence, average daily feed intake (ADFI), average daily gain (ADG), and gain : feed (G : F) ratio. This suggests that the diarrhoea was due to digestive disorders that did not result from enterotoxigenic Escherichia coli infection. Supplementation with either Spirulina or Chlorella did not affect ADFI, ADG and G : F in trials 1 and 2 (P>0.10). Diarrhoea incidence was reduced in CV pigs compared with NC, SP and PC pigs (P<0.05). Total tract digestibility in pig receiving microalgae was greater for gross energy (P<0.05), and tended to be greater for dry matter, organic matter and NDF (P<0.10) compared with NC and PC pigs. Villus height at the jejunum was greater in SP and CV pigs compared with NC and PC pigs (P<0.05). This study shows a potential effect of both Spirulina and Chlorella supplementation on intestinal development and a potential of Chlorella supplementation to manage mild digestive disorders. Further investigation is necessary to determine the mechanism action of Spirulina and Chlorella on gut health and physiology.     

Lysine requirements of finishing boars and gilts: A meta-analysis

The expected increase in boar (pig entire male) production while societal concerns for castration increase requires good estimations of their nutrient requirements. In this work, a meta-analytical approach was used to overcome the inconsistent results between studies that compared lysine requirements of boars and gilts. For this meta-analysis, data from 14 different studies analysing the effect of increasing dietary lysine on growth performance of finishing pigs, 70–100 kg average body weight, were extracted from 11 publications. Those studies represented 128 different treatments (53 for boars and 75 for gilts). Diets were reformulated based on NRC (2012) ingredient values to calculate standardized ileal digestible lysine to net energy ratio (SID Lys:NE) and daily SID Lys intake using average daily feed intake (ADFI). As expected, no evidence for differences in ADFI (P = 0.303) was observed between boars and gilts. However, boars grew faster (P < 0.001) and had higher gain to feed (G:F; P < 0.001). The divergent effect of SID Lys:NE on average daily gain (ADG) and G:F was analysed in a quadratic polynomial model showing different parameters for each sex (P < 0.001). Although performance between sexes was similar at low SID Lys:NE, differences were greater at higher SID Lys:NE. Furthermore, broken-line linear, broken-line quadratic (BLQ) and quadratic polynomial (QP) models were fitted to each sex to determine SID Lys:NE and SID Lys daily intake requirements to maximize ADG and G:F. Overall, QP models showed the best fit, and reported that to reach maximum ADG 0.88 (95% CI:[0.82–0.94]) or 1.01 (95% CI:[0.91–1.11]) g SID Lys/MJ, NE was required for gilts and boars, respectively. However, boar ADG was best fitted by BLQ using SID Lys daily intake as independent variable, with the requirement for maximum ADG at 24.2 (95% CI:[21.3–27.2]) g SID Lys/day. The three models reported wide confidence intervals for the requirements at maximum performance, and consequently those were overlapped when comparing boars and gilts. Maximum boars’ productive performance when dietary lysine was not limiting was 116% of gilts, and at those levels the amount of SID Lys intake required per kg gain was similar between both sexes. Thus, because ADFI and Lys efficiency of gain was similar, the requirement differences were driven by the increased growth rate and gain to feed ratio between boars and gilts. In conclusion, the present study confirmed a greater productive response of boars compared to gilts when increasing dietary lysine.     

Meta-analysis of feed intake and growth responses of growing pigs after a sanitary challenge

Sanitary challenges negatively affect feed intake and growth, leading to a negative impact on animal well-being and economic losses. The aim of this study was to carry out a meta-analysis to quantify the dynamic feed intake and growth responses of growing pigs after a sanitary challenge. A database was constructed using 122 published experiments reporting the average daily feed intake (ADFI) and the average daily gain (ADG) of pigs subjected to one of six sanitary challenges: digestive bacterial infections, poor housing conditions, lipopolysaccharide (LPS) challenges, mycotoxicoses, parasitic infections and respiratory diseases. The responses to experimental challenges were calculated relative to that of a control group. Statistical analyses were carried out for each challenge to quantify the mean and the dynamic responses in feed intake and growth and to identify the basis of the reduction in growth (i.e. reduction in feed intake or reduction in feed efficiency related to changes in maintenance requirements). All challenges resulted in a reduction in ADFI and ADG, with the strongest responses for mycotoxicoses, respiratory diseases and digestive bacterial infections (8% to 23% reduction in ADFI and 16% to 29% reduction in ADG). The reduction in ADG was linearly related to the reduction in ADFI for digestive bacterial infections, LPS challenge, parasitic infections and respiratory diseases. For poor housing conditions and mycotoxicoses, the relationship was curvilinear. A 10% reduction in ADFI resulted in a reduction in ADG varying from 10% for mycotoxicoses to 43% for digestive bacterial infections. More than 70% of the reduction in ADG could be explained by the reduction in ADFI for mycotoxicoses, LPS challenge and respiratory diseases. For challenges associated with the gastrointestinal tract, a large part of the reduction in ADG was due to an increase in maintenance requirements, suggesting digestive and metabolic changes. A dynamic pattern in the reduction in feed intake and growth rate could be identified for digestive bacterial infections, mycotoxicoses and respiratory diseases. For digestive bacterial infections and mycotoxicoses, pigs did not fully recover from the challenge during the experimental period. The results of this study can be used to quantify the effects of a sanitary challenge in growth models of pigs.     

Requirement of standardized ileal digestible valine to lysine ratio for 8- to 14-kg pigs

The objective was to define the Val requirement for weaned piglets in the context of reducing the dietary protein content. A dose–response experiment was conducted to estimate the standardized ileal digestible (SID) Val to Lys ratio required to support the optimum growth of post-weaned piglets. In this study, 96 pigs weighing 8 kg were allotted to one of six dietary treatments (16 pigs for each dietary treatment) and were housed individually. Diets were formulated to provide 0.58, 0.62, 0.66, 0.70, 0.74 and 0.78 SID Val : Lys by adding graded levels of crystallinel-Val to the 0.58 SID Val : Lys diet. Lysine was sub-limiting and supplied 90% of the recommendation (10.95 g SID Lys/kg equal to 11.8 g/kg total Lys). Average daily feed intake (ADFI), average daily gain (ADG) and gain to feed ratio (G : F) were determined during a 14-day period ofad libitum feeding. Blood and urine samples were taken at the end of each week (day 7 and 14 of the experiment) 3 h after feeding the experimental diets. The maximum ADFI and ADG were obtained in pigs fed the 0.78 SID Val : Lys diet; it was not different from the results of pigs fed 0.70 SID Val : Lys diet. The highest G : F was obtained in pigs fed 0.70 SID Val : Lys. The plasma concentration of Val increased linearly (P<0.001) as the dietary SID Val : Lys increased. The increasing dietary Val : Lys also resulted in a linear increase in Cys (P<0.001) and a quadratic increase in Arg (P=0.003), Lys (P=0.05) and Phe (P=0.009). The plasma Gly showed a quadratic decrease (P=0.05) as the dietary Val : Lys increased. Neither plasma nor urinary urea to creatinine ratio was affected by treatment. The minimum SID Val : Lys required to maximize ADFI, ADG and G : F was estimated at 0.67 SID Val : Lys by a broken-line model, and at 0.71 SID Val : Lys by a curvilinear plateau model. The Val deficiency caused a reduction in ADFI, and Val supplementation above the requirement did not impair animal performance. In conclusion, 0.70 SID Val : Lys is suggested as the Val requirement for 8 to 14 kg individually housed pigs.     

Effects of dietary chromium picolinate and peppermint essential oil on growth performance and blood biochemical parameters of broiler chicks reared under heat stress conditions

A study was conducted using 240 female day-old broiler chicks to evaluate the effects of dietary chromium picolinate (CrPic), peppermint essential oil (P.mint), or their combination on growth performance and blood biochemical parameters of female broiler chicks raised under heat stress conditions (HS, 23.9 to 38 °C cycling). Average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) were obtained from 1 to 42 days of age. Furthermore, at the end of the experiment (day 42), birds were bled to determine some blood biochemical parameters and weighed for final body weight (BW). ADFI, ADG, and BW were not influenced significantly by dietary CrPic and P.mint (P?>?0.05). A significant interaction between dietary CrPic and P.mint on FCR (P?=?0.012) was detected. FCR significantly decreased in chicks fed the diet including both CrPic and P.mint compared with the CrPic group. Significant interaction between dietary P.mint and CrPic on serum concentrations of triglycerides, glucose, and albumin were observed (P?<?0.05), but the other measured blood biochemical parameters were not statistically affected by dietary treatments (P?>?0.05). The serum concentrations of glucose, triglycerides were decreased (P?<?0.05) in broilers fed the diet including both CrPic and P.mint. Plasma chromium (Cr) content increased significantly (P?<?0.05) in birds fed the CrPic-included diet compared with the control group (P?<?0.05). From the results of the present experiment it can be concluded that dietary supplementation with combined P.mint and CrPic could have beneficial effects on some blood biochemical parameters of female chicks reared under heat stress conditions.     

Effects of composition and density of the group on the performance,behaviour and age at puberty in swine

Two hundred and eighteen cross-bred pigs (Duroc × Hampshire × Landrace × Yorkshire) were assigned to a 3 × 2 factorial experiment; the factors being composition of the group and density. The composition of the group factor consisted of pigs not reaggregated (NR), re-aggregated below the median body weight (RBMW), and re-aggregated above the median body weight (RAMW) at the time of transfer to the finishing pens. The density factor consisted of groups of 6 or 12 pigs/pen. Two trials with 2 replications of each trial were conducted. Twenty-six gilts from Trial I were used to determine their age and ovulation rate at the pubertal oestrus. During the nursery phase, composition of the group had no effect (P>0.05) on average daily feed intake (ADFI) or feed efficiency (F/G). Pigs in the NR and RAMW groups had a similar (P>0.05) average daily gain (ADG), whereas, those pigs in the RBMW group gained (P<0.05) at a slower rate. Pigs housed in groups of 6 had a higher (P<0.05) ADFI, had similar (P>0.05) ADG and poorer (P<0.05) F/G than those housed in groups of 12. During the finishing phase, composition of the group had no effect (P>0.05) on ADFI, ADG or F/G. Pigs housed in groups of 6 had a greater (P<0.05) ADFI and ADG, but similar (P<0.05) F/G compared to those housed in groups of 12. Correlation coefficients between the various behaviours and the performance variables suggested that the more active pens of pigs gained less per day and were less efficient. Gilts housed in the NR groups of 6 were younger (P<0.05) at puberty than gilts in the other groups of 6 or 12. Also, gilts housed in the RBMW groups of 6 were younger (P<0.05) at puberty than those housed in the RAMW groups of 6, whereas those housed in the RBMW groups of 12 were older (P<0.05) at puberty than those housed in the RAMW groups of 12. Ovulation rate was not affected (P>0.05) by composition of the group, density or their interaction. In summary, composition and density of the group affected the performance of pigs and was correlated to some of the behavioural measurements. The most noticeable effect was that these same factors caused a delay in the onset of puberty in gilts.     

Thermoregulatory responses during thermal acclimation in pigs divergently selected for residual feed intake

The objective of this study was to evaluate the performance and thermoregulatory responses during acclimation to high ambient temperature (Ta) of pigs from two lines selected for high (RFI⁺) or low (RFI^?) residual feed intake with the hypothesis that RFI^? pigs producing less heat would better tolerate high Ta. Pigs (50 kg initial body weight; 17 per line among which 10 of them were catheterized) were individually housed in a climatic-controlled room where Ta was maintained at 24.2?±?0.4 °C during 7 days and thereafter at 30.4?±?0.7 °C during 14 days. Irrespective of Ta, RFI^? pigs had lower feed intake (ADFI) and similar average daily gain (ADG) than RFI⁺ pigs. Whatever the line, ADFI, ADG, and feed efficiency decreased with increased Ta. Overall, the Ta increase resulted in an increase in rectal temperature (RT), skin temperature (ST), and respiratory rate (RR) within the first 24–48 h and, subsequently, in a decrease followed by stabilization. The RT decrease during acclimation occurred 24 h earlier in RFI^? pigs than in RFI⁺. Thyroid hormones and cortisol decreased at high Ta and it was similar in both lines. Based on performance and RT, ST, and RR responses, it seems that selection for low RFI tends to ameliorate pigs’ tolerance to high Ta. Nevertheless, this selection does not induce significant differences between lines in endocrine and metabolite responses during thermal stress.     

Meta-analysis of phosphorus utilization by growing pigs: effect of dietary phosphorus,calcium and exogenous phytase

Optimizing phosphorus (P) utilization in pigs requires improving our capacity to predict the amount of P absorbed and retained, with the main modulating factors taken into account, as well as precisely determining the P requirements of the animals. Given the large amount of published data on P utilization in pigs, a meta-analysis was performed to quantify the impact of the different dietary P forms, calcium (Ca) and exogenous phytases on the digestive and metabolic utilization criteria for dietary P in growing pigs. Accordingly, the amount of phytate P (PP) leading to digestible P (g/kg) was estimated to be 21%, compared with 73% for non-phytate P (NPP) from plant ingredients and 80% for NPP from mineral and animal ingredients (P < 0.001). The increase in total digestible dietary P following the addition of microbial phytase (PhytM) from Aspergillus niger (P < 0.001) was curvilinear and about two times higher than the increase following the addition of plant phytase, which leads to a linear response (P < 0.001). The response of digestible P to PhytM also depends on the amount of substrate, PP (PhytM² × PP, P < 0.001). The digestibility of dietary P decreased with dietary Ca concentration (P < 0.01) independently of phytase but increased with body weight (BW, P < 0.05). Although total digestible dietary P increased linearly with total NPP concentration (P < 0.001), retained P (g/kg), average daily gain (ADG, g/day) and average daily feed intake (ADFI, g/day) increased curvilinearly (P < 0.001). Interestingly, whereas dietary Ca negatively affected P digestibility, the effect of dietary Ca on retained P, ADG and ADFI depended on total dietary NPP (NPP × Ca, P < 0.01, P < 0.05 and P < 0.01, respectively). Increasing dietary Ca reduced retained P, ADG and ADFI at low NPP levels, but at higher NPP concentrations it had no effect on ADG and ADFI despite a positive effect on retained P. Although the curvilinear effect of PhytM on digestible P increased with PP (P < 0.001), this effect was lessened by total NPP for ADG and ADFI (PhytM × NPP and PhytM² × NPP, P < 0.05) and depended on both total NPP and Ca for retained P (PhytM² × NPP × Ca, P < 0.01). This meta-analysis improves our understanding of P utilization, with major modulating factors taken into account. The information generated will be useful for the development of robust models to formulate environmentally friendly diets for growing pigs.     

Animal and management factors influencing grower and finisher pig performance and efficiency in European systems: a meta-analysis

A meta-analysis on the effects of management and animal-based factors on the performance and feed efficiency of growing pigs can provide information on single factor and interaction effects absent in individual studies. This study analysed the effects of such factors on average daily gain (ADG), feed intake (FI) and feed conversion ratio (FCR) of grower and finisher pigs. The multivariate models identified significant effects of: (1) bedding (P<0.01), stage of growth (P<0.001) and the interaction bedding×lysine (P<0.001) on ADG. ADG was higher on straw compared with no bedding (710 v. 605 g/day). (2) FI was significantly affected by stage of growth (P<0.01), bedding (P<0.01), group composition (P<0.05), group size (P<0.01), feed CP content (P<0.01), ambient temperature (P<0.01) and the interaction between floor space and feed energy content (P<0.001). Pigs housed on straw had a lower FI in comparison with those without (1.44 v. 2.04 kg/day); a higher FI was seen for pigs separated by gender in comparison with mixed groups (2.05 v. 1.65 kg/day); FI had a negative linear relationship with group size, the CP content of the feed and ambient temperature. (3) Stage of growth (P<0.001), feed CP (P<0.001) and lysine content (P<0.001), ambient temperature (P<0.001) and feed crude fibre (CF) content (P<0.01) significantly affected FCR; there were no significant interactions between any factors on this trait. There was an improvement in FCR at higher ambient temperatures, increased feed CP and lysine content, but a deterioration of FCR at higher CF contents. For ADG, the interaction of bedding×lysine was caused by pigs housed without bedding (straw) having higher ADG when on a feed lower in lysine, whereas those with bedding had a higher ADG when on a feed higher in lysine. Interaction effects on FI were caused by animals with the least amount of floor space having a higher FI when given a feed with a low metabolisable energy (ME) content, in contrast to all other pigs, which showed a higher FI with increased ME content. The meta-analysis confirmed the significant effect of several well-known factors on the performance and efficiency of grower and finisher pigs, the effects of some less established ones and, importantly, the interactions between such factors.     

The potential effects of antioxidant feed additives in mitigating the adverse effects of corn naturally contaminated with <Emphasis Type="Italic">Fusarium</Emphasis> mycotoxins on antioxidant systems in the intestinal mucosa,plasma, and liver in weaned pigs

Seventy-two piglets (6.0 kg BW) were randomly distributed within six different dietary treatments to evaluate the effect of deoxynivalenol (DON) and the potential of four antioxidant feed additives in mitigating the adverse effects of DON on growth performances and oxidative status. Dietary treatments were as follows: control diet 0.8 mg/kg DON; contaminated diet (DON-contaminated diet) 3.1 mg/kg DON; and four contaminated diets, each supplemented with a different antioxidant feed additive, DON + vitamins, DON + organic selenium (Se)/glutathione (GSH), DON + quercetin, and DON + COMB (vitamins + Se/GSH + quercetin from the other treatments). Although DON was the main mycotoxin in the contaminated diet, this diet also contained 1.8 mg/kg of zearalenone (ZEN). The “mycotoxin” effects therefore included the combined effect of these two mycotoxins, DON, and ZEN. The DON-ZEN ingestion did not affect growth performances, average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F ratio), but partially induced oxidative stress in weaned pigs as shown by increased malondialdehyde (MDA) content in the plasma and superoxide dismutase (SOD) activity in liver (P?<?0.05). However, no change in the activity of other antioxidant enzymes or GSH concentrations was observed in plasma and liver of piglets fed the DON-contaminated diet (P?>?0.05). Supplementation with individual antioxidant feed additive had a limited effect in weaned pigs fed DON-ZEN-contaminated diets. Combination of antioxidants (vitamins A, C, and E, quercetin, and organic Se/GSH) reduced plasma and liver MDA content and SOD activity in liver (P?<?0.05) of piglets fed DON-ZEN-contaminated diets. Furthermore, this combination also reduced MDA content in the ileum (P?<?0.05), although activity of glutathione peroxidases (GPx), SOD or catalase (CAT) in the ileum was not affected by DON-ZEN contamination or antioxidant supplements. In conclusion, DON-ZEN contamination induced oxidative stress in weaned pigs and combination of antioxidant feed additives restored partially the oxidative status. Further studies will be necessary to assess whether the effects of antioxidant feed additives on oxidative status are specific when feed is contaminated with DON-ZEN.     

The effect of zinc oxide supplementation on the stability of the intestinal flora with special reference to composition of coliforms in weaned pigs

The effect of a dietary supplementation of zinc oxide (ZnO) on the stability of the intestinal flora and on the composition of coliforms in weaned pigs was investigated. Faecal floras were characterized by their metabolic activities and fermentative capacity (FC) using the Phene Plate generalized microplate. Coliforms were characterized by conventional enumeration and by the Phene Plate-RS plates. The latter measured FC, phenotypic diversity, persistence of each coliform strain in piglets, and similarity among the coliform populations within groups. From weaning onwards, the control pigs (n = 5) were fed a basal diet ad libitum, while experimental pigs (n = 5) were given the same food supplemented with 2500 ppm ZnO. Metabolic fingerprinting of faecal floras indicated marked differences between the composition of floras of treated and control pigs during the first 2 weeks post-weaning. The FC of faecal flora in both groups decreased as pigs aged, but it was significantly (P 相似文献   

Comparative effect of different dietary inulin sources and probiotics on growth performance and blood characteristics in growing–finishing pigs

The study was focused on assessment of the effect of an extract of long-chain inulin (LCI) and dried tubers of Jerusalem artichoke (JA) and a multispecies probiotic preparation as well as a combination thereof on growth performance and blood parameters of fattening pigs. In total, 144 pigs (initial body weight 30.0 ± 0.5 kg) were used in a 98-d experiment. The six dietary treatments consisted of the control diet (Con), diet Con supplemented with probiotics (ConP) and four diets supplemented with LCI or JA alone or with probiotics (diets LCIP and JAP). Throughout the fattening period, there was a beneficial effect of the probiotic supplementation to the inulin-containing diets and the average daily gain (ADG) was increased by supplementation of probiotics in combination with inulin sources (p < 0.05). At the end of the fattening period, ADG and feed conversion ratio (FCR) were higher after supplementation of LCI only (p < 0.05). Compared with group ConP, in groups LCI and JA, the ADG and FCR were improved (p < 0.05). Only in the first fattening stage, the addition of the prebiotics and/or probiotics had an impact on the level of white blood cells and some biochemical indices in pigs. In younger animals, probiotic or LCI supplementation increased the IgG level (p < 0.05). There was also an interaction between the probiotics and JA resulting in increased IgG and IgA concentrations (p < 0.05). In the finishing period, LCI addition increased the IgM level (p < 0.05), whereas JA addition increased IgG and IgM levels as well (p < 0.05). In conclusion, both dietary sources of inulin and probiotic supplementation can improve the fattening performance and health status of growing pigs.     

Estimation of the leucine and histidine requirements for piglets fed a low-protein diet

Reduction of the CP content in the diets of piglets requires supplementation with crystalline essential amino acids (AA). Data on the leucine (Leu) and histidine (His) requirements of young pigs fed low-CP diets are limited and have primarily been obtained from nonlinear models. However, these models do not consider the possible decline in appetite and growth that can occur when pigs are fed excessive amounts of AA such as Leu. Therefore, two dose-response studies were conducted to estimate the standardised ileal digestible (SID) Leu: lysine (Lys) and His: Lys required to optimise the growth performance of young pigs. In both studies, the average daily gain (ADG), average daily feed intake (ADFI) and gain-to-feed ratio (G: F) were determined during a 6-week period. To ensure that the diets had sub-limiting Lys levels, a preliminary Lys dose-response study was conducted. In the Leu study, 60 35-day-old piglets of both sexes were randomly assigned to one of five treatments and fed a low-CP diet (15%) with SID Leu: Lys levels of 83%, 94%, 104%, 115% or 125%. The His study used 120 31-day-old piglets of both sexes, which were allotted to one of five treatments and fed a low-CP diet (14%) with SID His: Lys levels of 22%, 26%, 30%, 34% or 38%. Linear broken-line, curvilinear-plateau and quadratic-function models were used for estimations of SID Leu: Lys and SID His: Lys. The minimum SID Leu: Lys level needed to maximise ADG, ADFI and G: F was, on average, 101% based on the linear broken-line and curvilinear-plateau models. Using the quadratic-function model, the minimum SID Leu: Lys level needed to maximise ADG, ADFI and G: F was 108%. Data obtained from the quadratic-function analysis further showed that a ±10% deviation from the identified Leu requirement was accompanied by a small decline in the ADG (−3%). The minimum SID His: Lys level needed to maximise ADG, ADFI and G: F was 27% and 28% using the linear broken-line and curvilinear-plateau models, respectively, and 33% using the quadratic-function model. The preferred model to estimate the His requirement was the curvilinear-plateau model. However, a 10% reduction in the SID His: Lys level was associated with an 11% reduction in the ADG. In conclusion, the SID Leu: Lys level needed to maximise growth was 108% when using the quadratic-function model as the best-fitting model. The minimum SID His: Lys level required to optimise growth was 28% when using the curvilinear-plateau model as the best-fitting model.     

Effect of high dietary copper on weight gain and neuropeptide Y level in the hypothalamus of pigs

An experiment was performed to examine the effect of dietary copper supplementation on weight gain, neuropeptide Y (NPY) concentration and NPY mRNA expression level in the hypothalamus of pigs. Forty-five crossbred pigs were randomly assigned to three groups of 15 pigs, each comprising five replicates of 3 animals. Pigs were allocated to diets that contained 10 mg/kg (as a control), 125 and 250 mg/kg copper as CuSO₄. Live weight gain and feed conversion efficiency was determined at the end of the experiment and five pigs, selected at random from each group, were slaughtered and the hypothalami collected for determination of NPY concentration and NPY mRNA expression level. The results showed that average daily gain (ADG) and average daily feed intake (ADFI) were higher and feed:gain (F:G) ratio was lower in pigs fed the diets with 125 and 250 mg/kg copper (P<0.05), respectively, than in pigs fed a diet with 10 mg/kg copper, but that there was no statistically significant difference in growth performance between animals of the 125 mg/kg and the 250 mg/kg copper groups. Furthermore, pigs fed diets with 125 and 250 mg/kg copper had higher NPY concentrations and NPY mRNA expression levels in their hypothalamus than control animals. The data indicated that 125 and 250 mg/kg copper gave similar responses in terms of weight gain, whilst high dietary copper could enhance NPY concentration and NPY mRNA expression level in the hypothalamus of pigs. High dietary copper appears to increase feed intake and promote weight gain by enhancing NPY concentration and NPY mRNA expression level in the hypothalamus of pigs.     

Zinc and Copper Levels in Bladder Cancer: A Systematic Review and Meta-Analysis

It is well documented that oxidative stress is involved in the pathogenesis of bladder cancer. Zinc (Zn) and copper (Cu) are important components of antioxidants. However, the association between Zn or Cu levels and bladder cancer remains elusive. The present study was designed to investigate the alteration of serum and urinary levels of Zn or Cu in bladder cancer patients compared with controls by performing a systematic review. We searched the PubMed, Embase, and Cochrane databases from January 1990 to March 2013 to identify studies that met our predefined criteria. Six studies were included. Bladder cancer patients demonstrated significantly lower levels of serum Zn (three studies, random effects standard mean deviation (SMD): ?1.072, 95 % CI: ?1.489 to ?0.656, P <0.0001), markedly higher levels of serum Cu (three studies, random effects SMD: 1.069, 95 % CI: 0.302 to 1.836, P?=?0.006) and urinary Zn (three studies, random effects SMD: 2.114, 95 % CI: 0.328 to 3.899, P?=?0.02) compared with controls. No obvious difference was observed in urinary Cu levels between bladder cancer patients and controls (two studies, random effects SMD: 0.153, 95 % CI: ?0.244 to 0.55, P?=?0.449). No evidence of publication bias was observed. In conclusion, the disorder of Zn and Cu is closely associated with bladder cancer. Frequent monitoring and early intervention should be recommended.     

Impact of Porcine Epidemic Diarrhea on Performance of Growing Pigs

The impact of porcine epidemic diarrhea virus (PEDv) infection on the US pork industry has mainly been attributed to the mortality that it causes in suckling piglets, and, consequently, much effort has been invested in the quantification of its effect in sow farms. However, no information on the performance of surviving pigs that were exposed to the PEDv as piglets is available. Here, a retrospective cohort study to evaluate the impact of porcine epidemic diarrhea virus (PEDv) infection on growing pigs’ performance, as indicated by mortality, average daily gain (ADG), average daily feed intake (ADFI), and feed conversion ratio (FCR) was performed using production records from weaned pigs in nursery and wean-to-finish sites from sow farms that became PEDv-infected between May 2013 and June 2014. Production records from the first batch of growing pigs weaned in infected flows after the PEDv outbreak (“infected batches”) were compared with those from pigs weaned within the previous 14 to 120 days (“control batches”). Performance records from infected and control batches, paired by flow, were compared using non-parametric paired tests. Mortality, ADG and FCR were significantly different in PEDv-positive (infected) compared with PEDv-negative (control) batches, with a mean increase of mortality and FCR of 11% and 0.5, respectively, and a decrease of ADG of 0.16 lb/day. Our results demonstrate a poorer performance of growing pigs weaned after a PEDv outbreak compared with those weaned within the previous 14-120 days, suggesting that in addition to the mortality induced by PEDv in suckling pigs, the disease also impairs the performance of surviving pig. These findings help to quantify the impact of PEDv infection in the US and, ultimately, contribute to efforts to quantify the cost-effectiveness of disease prevention and control measures.     

Dietary supplementation with <Emphasis Type="Italic">Astragalus</Emphasis> polysaccharide enhances ileal digestibilities and serum concentrations of amino acids in early weaned piglets

Two experiments were conducted to evaluate the effects of dietary supplementation with Astragalus polysaccharide (APS) on growth performance, apparent ileal digestibilities (AID) of amino acids (AA), and their serum concentrations in early weaned piglets. In Exp. 1, 60 pigs were weaned at 21 days of age (BW 7.35 ± 0.23 kg) and allocated to three treatments (20 pigs/treatment), representing supplementing 0.0% (control), 0.02% colistin (antibiotic), or 0.1% APS to a corn- and soybean meal-based diet. Average daily gain (ADG), average daily feed intake (ADFI), and feed/gain ratio (F/G) were measured weekly. Blood samples were obtained from five pigs selected randomly from each treatment for the measurement of serum free AA concentrations on days 7, 14, and 28. In Exp. 2, 12 pigs were weaned at 21 day of age (BW 7.64 ± 0.71 kg), assigned to three treatment groups as in Exp. 1, and surgically fitted with a simple T-cannula at the terminal ileum. Ileal digesta samples were obtained for the measurement of AID of AA on days 7, 14 and 28. Dietary APS did not affect ADFI, but enhanced (P < 0.05) ADG by 11 and 4.4%, and improved F/G by 5.6 and 8.4%, respectively, compared with the control and antibiotic groups. Addition of APS to the diet increased AID and serum concentrations of most nutritionally essential and non-essential AA (including arginine, proline, glutamate, lysine, methionine, tryptophan, and threonine) on days 14 and 28. Circulating levels of total AA were affected by the age of pigs and treatment × time interaction. Collectively, these findings indicate that APS may ameliorate the digestive and absorptive function and regulate AA metabolism to beneficially increase the entry of dietary AA into the systemic circulation, which provide a mechanism to explain the growth-promoting effect of APS in early weaned piglets.