Effect of dietary inorganic sulfur level on growth performance, fecal composition, and measures of inflammation and sulfate-reducing bacteria in the intestine of growing pigs

Posted in: Environment, Production by admin on July 26, 2011 | No Comments

Two experiments investigated the impact of dietary inorganic S on growth performance, intestinal inflammation, fecal composition, and the presence of sulfate-reducing bacteria (SRB). In Exp. 1, individually housed pigs (n = 42; 13.8 kg) were fed diets containing 2,300 or 2,100 mg/kg of S for 24 d. Decreasing dietary S had no effect on ADG, ADFI, or G:F. In Exp. 2, pigs (n = 64; 13.3 kg) were fed diets containing 0, 0.625, 1.25, 2.5, or 5.0% CaSO4, thereby increasing dietary S from 2,900 to 12,100 mg/kg. Two additional diets were fed to confirm the lack of an impact due to feeding low dietary S on pig performance and to determine if the increased Ca and P content in the diets containing CaSO4 had an impact on growth performance. Pigs were fed for 35 d. Ileal tissue, ileal mucosa, and colon tissue were harvested from pigs fed the 0 and 5% CaSO4 diets (low-S and high-S, respectively) to determine the impact of dietary S on inflammation-related mRNA, activity of mucosal alkaline phosphatase and sucrase, and pathways of inflammatory activation. Real-time PCR was used to quantify SRB in ileal and colon digesta samples and feces. Fecal pH, sulfide, and ammonia concentrations were also determined. There was no impact on growth performance in pigs fed the diet reduced in dietary S or by the increase of dietary Ca and P. Increasing dietary S from 2,900 to 12,100 mg/kg had a linear effect on ADG and a cubic effect on ADFI and G:F. Real-time reverse-transcription PCR analysis revealed that pigs fed high-S increased the relative abundance of intracellular adhesion molecule-1, tumor necrosis factor-α, and suppressor of cytokine signaling- 3 mRNA, and tended to increase the relative abundance of IL-6 mRNA in ileal tissue. Likewise, pigs fed high-S had reduced abundance of nuclear factor of κ light polypeptide gene enhancer in B-cells inhibitor-α and increased phospho-p44/p42 mitogen-activated protein kinase in ileal tissue, but there was no effect of dietary S on mucosal alkaline phosphatase or sucrase activity. Pigs fed the high-S diet had decreased total bacteria in ileal digesta, but increased prevalence of SRB in colon contents. Fecal sulfide was increased and fecal pH was deceased in pigs fed high-S. The data indicate that growing pigs can tolerate relatively high amounts of dietary inorganic S, but high dietary S content alters inflammatory mediators and intestinal bacteria.

For more information the full article can be found at http://jas.fass.org/

Net energy of soybean oil and choice white grease in diets fed to growing and finishing pigs

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For more information the full article can be found at http://jas.fass.org/

Effects of dietary aflatoxin on the hepatic expression of apoptosis genes in growing barrows

Posted in: Production by admin on July 25, 2011 | No Comments

The most common and toxic form of aflatoxin, aflatoxin B1 (AFB1), is produced by molds growing on crops. Use of moldy corn can result in high concentrations of AFB1 in swine diets, which could potentially lead to an increased incidence of aflatoxicosis, a disease associated with decreased health and performance through reduced feed intake, reduced BW gain, and impaired liver function. The objective of this study was to determine the effects of AFB1 on the hepatic gene expression of growing barrows. Ninety Duroc × Yorkshire crossbred barrows (age = 35 +/- 5; initial BW = 14.2 +/- 3.0 kg) were allocated to 9 pens with 10 pigs per pen, and randomly assigned in a 3 × 3 factorial arrangements of treatments to receive diets containing 0 μg/kg of AFB1, 250 μg/kg of AFB1, or 500 μg/kg of AFB1 for 7, 28, or 70 d. Because performance was most affected in animals administered AFB1 for an extended period, liver samples from d 70 animals were used for RNA-sequencing analysis. Of 82,744 sequences probed, 179 had transcripts that were highly correlated with treatment. Of the 179 significant transcripts, 46 sequences were negatively and 133 sequences positively related to treatment. Forty-three unique functional groups were identified. Genes within the apoptosis regulation functional group were selected for confirmation of d 70 gene expression differences using real-time reverse-transcription (RT)-PCR (n = 4 genes), and investigation of d 7 expression to identify early responses to AFB1 (n = 15 genes) using real-time RT-PCR. Expression of the 4 apoptosis genes selected for confirmation, cyclin-dependent kinase inhibitor 1A, zinc finger matrin type 3, kininogen 1, and pim-1 oncogene, was confirmed with real-time RT-PCR. Of the 15 genes tested in d 7 liver samples, 4 were differentially expressed: cyclin-dependent kinase inhibitor 1A; zinc finger matrin type 3; tyrosine 3-monooxygenase/ tryptophan 5-monooxygenase activation protein, zeta polypeptide; and apoptosis enhancing nuclease. Results from this study demonstrate that administration of an AFB1-contaminated diet to growing barrows alters hepatic gene expression, and in particular apoptosis genes.

For more information the full article can be found at http://jas.fass.org/

Effect of maternal protein restriction on lipid metabolism in Meishan piglets at weaning

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The present study aimed to determine the effects of maternal protein restriction on lipid metabolism of piglets at weaning and the associated underlying mechanism employing Meishan pigs as model. Sixteen Meishan sows were assigned to the control group and the maternal protein restriction group (MPR). The treated group was fed a low-protein diet containing 6% protein during pregnancy followed by 7% protein during lactation, whereas the control group received 12% and 14% protein during pregnancy and lactation, respectively. Blood and subcutaneous fat of piglets were sampled at weaning. The results showed that in MPR piglets’ body weight and backfat thickness were significantly decreased compared to control piglets. Leptin mRNA expression was significantly down-regulated and the leptin content showed a decreased tendency in subcutaneous fat of MPR group though the serum leptin concentration was unchanged. The lipolytic lipase activity (including Hormone sensitive lipase, HSL and adipose tissue triglyceride lipase, ATGL) in subcutaneous fat was significantly increased in MPR group. The fatty acid synthase (FAS) mRNA expression decreased significantly although CCTTA enhancer-binding protein (C/ EBP-β) and peroxisome proliferators-activated receptor γ (PPAR-γ) mRNA expression showed no obviously changes in MPR group compared with the control. Furthermore, though no alteration was detected for total perilipin protein level, the mRNA expression of perilipin was significantly decreased and the phosphorylation level of perilipin protein demonstrated an increased tendency in the MPR group. The present study indicates that the lower lipid deposition in piglets of maternal protein restriction group at weaning may be mediated by the increased lipolysis in the subcutaneous fat demonstrated by increased lipolytic lipase activity and higher perilipin phosphorylation level. These alterations may influence the lipid metabolism of later life.

The effect of phosphorus restriction during the weaner-grower phase on compensatory growth, serum osteocalcin and bone mineralization in gilts

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 Ninety-six female pigs with an initial bodyweight (BW) of 10.0±1.6 kg were assigned to 4 dietary treatments to determine the effects of restricting dietary phosphorus (P) level during the weaner-grower [approximately 10 to 50 kg BW; day (d) 0 to 59] and finisher (approximately 50 to 100 kg BW; d 59 to 131) period on growth performance, serum osteocalcin concentration, bone development and calculated P utilization. The dietary treatments were: 4.0 g total P (tP)/kg from d 0 to 131 (LL); 4.0 g tP/kg from d 0 to d 59 and 6.0 g tP/kg from d 59 to 131 (LH); 6.0 g tP/kg from d 0 to 131 (HH) and 6.0 g tP/kg from d 0 to 59 and 4.0 g tP/kg from d 59 to 131 (HL). During the weaner-grower period (d 0 to 59), pigs offered high P diets had higher daily gain, feed intake, P intake, bone ash and serum osteocalcin concentration compared to pigs offered low-P diets. Pigs offered LH, HH and HL diets had higher average daily gain compared to pigs offered LL diet from d 59 to 131. Pigs offered LL diet had a lower carcass weight compared to pigs offered LH, HH and HL diets on d 131. Pigs offered LL diet had a lower bone ash, bone P and bone calcium concentration than pigs offered LH, HL and HH diets on d 131. Pigs offered LH diet had higher concentration of osteocalcin compared to pigs offered LL, HH and HL diets on d 88 and 108. In conclusion, compensatory effect occurred in growth performance and bone mineral concentration at the termination of the finisher stage when high P was introduced at the initiation of the finisher stage, following consumption of a low-P diet during the weaner-grower stage. However, pigs offered LH diet did not surpass the level of growth performance or bone mineralization achieved by pigs offered HH diet.

For more information the full article can be found at http://www.journals.elsevierhealth.com/periodicals/livsci

Effects of feeding whole crop rice combined with soybean oil on growth performance, carcass quality characteristics, and fatty acids profile of Longissimus muscle and adipose tissue of pigs

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This study was conducted to determine the effects of soybean oil supplementation on growth performance, carcass characteristics and fatty acids composition in muscle and adipose tissue of pigs fed on whole crop rice (WCR). Forty-eight pigs (Duroc × Landrace × Yorkshire, 36 kg) were randomly assigned to four treatments with three replications each. The diets included the ground WCR at levels of 0, 8, 12 or 16% and supplemented with soybean-oil at levels of 0, 2, 3 and 4 %, accordingly replacing the maize, and designated as control C, T1, T2 and T3, respectively. All pigs at about 90 kg were slaughtered to determine carcass quality and fatty acid composition. In growing period, the daily feed intake was significantly lower for pigs fed the diets containing WCR than for those on the control diets. The pigs on T3 diet had significantly lower average daily gain than those on C, T1 or T2 diets. The feed conversion ratio was significantly lower in pigs on T1 or T2 diets than on the control.No significant difference was found in daily feed intake, average daily gain and feed conversion ratio among pigs on different diets in finishing period. The carcass characteristics did not differ among different treatments. The water holding capacity of loin muscle was significantly lower for pigs fed diets containing WCR than for those on the control. There were no significant differences in meat color, marbling, pH and cooking loss among pigs on different diets. The concentration of saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) in back fat decreased significantly with the inclusion of soybean oil in the diet. The same trend was showed in Longissimus muscle, and SFA in T1 and MUFA in T3 were significantly lower than those in the control, respectively. The polyunsaturated fatty acid (PUFA), n-6 PUFA and n-3 PUFA were significantly higher in the Longissimus muscle and backfat of pigs fed diet with soybean oil and WCR than those in the control. The Longissimus muscle and back fat of pigs fed the diet with soybean oil and WCR were significantly higher in PUFA/SFA and lower in n-6/n-3 ratio than those of the control, with exception of the ratio of n-6/n-3 in muscle for T1. The study suggests that whole crop rice could be used as a feed ingredient for growing-finishing pigs with soybean-oil supplementation and that the treatment including soybean oil would improve the fatty acid profile of the carcass as food for humans.

For more information the full article can be found at http://www.journals.elsevierhealth.com/periodicals/livsci

Effect of selection for residual feed intake on feeding behavior and daily feed intake patterns in Yorkshire swine

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Residual feed intake (RFI) is a measure of feed efficiency defined as the difference between observed and predicted feed intake based on average requirements for growth and maintenance. The objective of this study was to evaluate the effect of selection for decreased RFI on feeding behavior traits and to estimate their relationships with RFI. Three data sets from the 4th and 5th generations of a selection experiment with a line selected for reduced RFI (LRFI) and a randomly selected control line (CTRL) were analyzed. Lines were mixed in pens of 16 and evaluated for feeding behavior traits obtained from a single-space electronic feeder over a growing period of ~3 mo before ~115 kg. The following traits were evaluated as averages over the entire test period and over the first and second half of the test period: number of visits per day and hour; occupation time per day, visit, and hour; feed intake (FI) per day, visit, and hour; and FI rate per visit. Models used included fixed effects of line and feeder, covariates of on-test age and FI per day, and random effects of pen, on-test group, sire, and litter. Repeated measures models were used to analyze feeding patterns during the day. The LRFI pigs had significantly less FI per day than CTRL pigs for all 3 data sets. With adjustment for FI per day, line differences of all traits were in the same direction for all 3 data sets but differed in significance and size. Feed intake per visit and hour and visits per day and hour did not differ between lines, but the trend was for LRFI pigs to have fewer visits, in particular during peak eating times. The LRFI pigs had a greater feeding rate and less occupation time per day, visit, and hour than CTRL pigs, but this was not significant for all data sets. Correlations of RFI with FI per day and visit and visits per day were positive. Average daily gain was positively correlated with FI per day and visit and occupation time per visit but negatively correlated with visits per day. Feed intake per day was positively correlated with backfat. In conclusion, feed efficiency may be affected by FI behavior because selection for decreased RFI has resulted in pigs that spend less time eating and eat faster.

For more information the full article can be found at http://jas.fass.org/

Drinking behavior in nursery pigs: Determining the accuracy between an automatic water meter versus human observers

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Assimilating accurate behavioral events over a long period can be labor-intensive and relatively expensive. If an automatic device could accurately record the duration and frequency for a given behavioral event, it would be a valuable alternative to the traditional use of human observers for behavioral studies. Therefore, the objective of this study was to determine the accuracy in the time spent at the waterer and the number of visits to the waterer by individually housed nursery pigs between human observers scoring video files using Observer software (OBS) and an automatic water meter Hobo (WM, control) affixed onto the waterline. Eleven PIC USA genotype gilts (22d of age; 6.5kg of BW) were housed individually in pens with ad libitum access to a corn-based starter ration and one nipple waterer. Behavior was collected on d 0 (day of weaning), 7, and 14 of the trial using 1 color camera positioned over 4 attached pens and a RECO-204 DVR at 1 frame per second. For the OBS method, 2 experienced observers recorded drinking behavior from the video files, which was defined as when the gilt placed her mouth over the nipple waterer. Data were analyzed using nonparametric methods and the general linear model and regression procedures in SAS. The experimental unit was the individual pen housing 1 gilt. The GLM model included the method of observation (WM vs. OBS) and time (24 h) as variables, and the gilt nested within method was used as the error term. Gilts consumed more water on d 14 than on d 0. The time of day affected the number of visits and the time spent at the waterer regardless of the method. However, the OBS method underestimated the number of visits to the waterer (3.48 visits/h for OBS vs. 4.94 for WM) and overestimated the time spent at the waterer (22.6 s/h for OBS vs. 13.9 for WM) compared with WM. The relationship between the 2 methods for prediction of time spent at the waterer and number of visits made by the gilts was weak. Collectively, these data indicate that the use of the traditional OBS method for quantifying drinking behavior in pigs can be misleading. Quantifying drinking behavior and perhaps other behavioral events via the OBS method must be more accurately validated. 

For more information the full article can be found at http://jas.fass.org/

The effect of selection for residual feed intake on general behavioral activity and the occurrence of lesions in Yorkshire gilts

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The objectives of this study were to determine the effect of selection for improved residual feed intake on behavior, activity, and lesion scores in gilts in their home pen. A total of 192 gilts were used, 96 from a line that had been selected for decreased residual feed intake over 5 generations (LRFI) and 96 from a randomly bred control line. Gilts were housed in 12 pens (16 gilts/pen; 0.82 m2/gilt) containing 8 gilts from each line in a conventional grow-finish unit. Twelve hours of video footage were collected on the day of placement and then every 4 wk for 3 more observational periods. Video was scored using a 10-min instantaneous scan sampling technique for 4 postures (standing, lying, sitting, and locomotion) and 1 behavior (at drinker). Categories of active (standing, locomotion, and at drinker) and inactive (sitting and lying) were also created. Lesion scores were collected 24 h after behavior collection had begun. The body of a gilt was divided into 4 regions, with each region receiving a score of 0 (0 lesions) to 3 (5+ lesions). All statistical analyses used Proc Mixed of SAS. Data were analyzed separately for the day of placement and the subsequent 3 rounds. General activity was summarized on a percentage basis by each posture and behavior and subjected to an arcsine square root transformation to normalize data and stabilize variance. Analysis was performed on each behavior and posture. Lesion scores for each region of the body were analyzed as repeated measures. There were no differences between genetic lines for all postures and the behavior at drinker on the day of placement. However, over subsequent rounds it was observed that LRFI gilts spent less time standing, more time sitting, and were less active overall. Gilts from the LRFI line had decreased lesion scores on the day after placement. However, over subsequent rounds there were no differences between the genetic lines. In conclusion, on the day of placement there were no postural, behavior, or general activity differences between genetic lines, but LRFI gilts had decreased lesion scores. Behavioral differences were observed between genetic lines over subsequent rounds, with LRFI gilts becoming less active, but there were no differences in lesion scores. 

For more information the full article can be found at http://jas.fass.org/

Endocrine response of gilts to various common stressors: A comparison of indicators and methods of analysis

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The first aim of the present study was to determine whether various common events encountered by pigs in commercial farms or experimental units induce activation of the sympathetic and hypothalamo-pituitary adrenal (HPA) axes. The second aim was to compare the efficiency of various indicators and methods of analysis to detect the occurrence of a stress reaction. Responses to two blood sampling methods, immobilization by snaring, brief electric shocks, loud noise, ear tagging, tattooing, biopsy, pen relocation or delayed feeding time have been evaluated. Series of blood and saliva samplings (from 10 min before to 120 min after stressor application) were collected for each stressor on a total of 8 catheterized sows. Plasma glucose, lactate, cortisol and ACTH levels as well as salivary cortisol were measured. Acute increases of cortisol or ACTH (at least at time points+5 or+15 min) were observed for intense noise, electric shocks, ear tagging, tattooing, biopsy, cava blood sampling, snaring and pen relocation. Snaring, relocation and vena cava blood sampling generated longer stress responses whereas delayed meal and tail blood sampling had no influence. Plasma lactate was also significantly increased in several time-points after stressor application contrarily to plasma glucose. Comparison of successive time points with the starting basal level and comparison with the control group were more sensitive methods to detect a stress response to moderate stressors like electric shocks and tattooing, than comparing the area under the curve. These data confirmed that salivary cortisol is a good indicator to measure the HPA response to a stressor, provided that post-treatment levels can be compared with pre-treatment levels.

For more information the full article can be found at http://www.sciencedirect.com/science/journal/00319384