Effect of fumaric acid, calcium formate and mineral levels in diets on the intake and growth performance of newly weaned pigs

peer-reviewedThe weaned pig has limited ability to acidify its stomach contents. The objective of this study (comprising three experiments) was to examine the effect of feeding diets containing fumaric acid (FA), calcium formate (CF) or diets of low acid binding capacity (ABC) on post-weaning pig performance. In all three experiments, pigs (10 per treatment) were weaned at 19 to 24 days, blocked on sex and weight and assigned at random to one of six treatments. In Experiment 1, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) low Ca (2.8 g/kg) and P (5.1 g/kg) (LCaP) diet for seven days followed by the control diet, (5) LCaP diet for seven days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control 15 g/kg CF. In Experiment 2, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) LCaP diet for 14 days followed by the control diet, (5) LCaP diet for 14 days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control diet. In Experiment 3, treatments were: (1) high Ca (HC) diet (12 g/kg), (2) medium Ca (MC) diet (9 g/kg), (3) low Ca (LC) diet (6 g/kg), (4) HC 20 g/kg FA, (5) MC 20 g/kg FA, and (6) LC 20 g/kg FA. Pigs were individually fed for 26 days. In Experiment 1, CF tended to depress daily feed intake (DFI) in the final two weeks (691 v. 759 and 749, (s.e. 19) g/day, P = 0.07) and overall average daily gain (322 v. 343 and 361 (s.e. 11) g/day, P = 0.09) compared with the control and FA supplemented diets, respectively. Feeding diets with LCaP for seven days post weaning increased DFI (208 v. 178, (s.e. 8) g/day, P < 0.01) in week 1 and tended to improve feed conversion rate in the first two weeks (1.65 v. 1.85, s.e. 0.10, P = 0.09). In Experiment 2, treatment had no significant effect on pig performance but feed conversion rate in weeks three and four was improved for Treatment 5 compared with Treatment 4 (1.30 v. 1.39 (s.e. 0.06) g/g, P < 0.01). In experiment 3, FA increased (P < 0.05) pig weight at day 14 (8.4 v. 7.7 (s.e. 0.2) kg) and feed intake in weeks one and two (223 v. 251, (s.e. 9) g/day). It is concluded that CF did not improve performance but reducing diet ABC or including FA in the diet did improve performance

Enhancement of pigmeat quality by altering pre-slaughter management

End of project reportThe studies presented in this report were conducted to investigate the effect of breed, slaughter weight, castration of male pigs and strategic feeding strategies on the performance of pigs to slaughter and on their carcass quality. The effect of breed, gender and feeding regimen on the performance of pigs and their carcass quality was examined in the first study (Section 3). From weaning to slaughter Landrace-sired pigs grew at a similar rate but had a better feed conversion efficiency compared with Duroc-sired pigs. Landrace-sired pigs also had a higher carcass lean and greater muscle depth than Duroc-sired pigs. Entire male pigs grew more efficiently, had lower lean content in their carcasses and had a reduced kill out yield when compared with gilts. The eye muscle depth was greater for gilts than entire males. Diluting the diet with grass-meal (GM) reduced growth rate, caused a deterioration in feed conversion efficiency, reduced back fat thickness, reduced eye muscle thickness and reduced kill out yield compared to the control feeding regimen of a cereal based diet. Compensatory growth was observed during a re-alimentation period following a period of diet dilution with grass-meal. However, where it did occur, in most cases it was only partial. Adding 5% rapeseed oil instead of lard to the finisher diet increased nitrogen utilization efficiency and phosphorous utilization efficiency. The effect of gender (boar, castrate, gilt) and slaughter weight (80 to 120kg) on pig performance, carcass quality, meat quality, and nitrogen excretion was investigated in the second study (Section 4). Boars grew faster than gilts and more efficiently than castrates or gilts. Castrates had a higher kill out yield than boars. Nitrogen excretion from castrates was similar to gilts which were both higher than that from boars. The processing value of carcasses from castrates may be higher than that of boars and gilts. In particular castrates had heavier loins and bellies than either boars or gilts. Carcasses from castrates and gilts had a higher temperature (recorded 24 hours post slaughter) than boars. However, pH24 was not affected by gender. The intramuscular fat content of the l. dorsi in castrates was higher than that of boars or gilts, however at 1.65% this was well below the level (2.0%) above which any noticeable sensory attributes might be detected. Feed intake increased with increasing slaughter weight and feed conversion efficiency deteriorated. N excretion also increased with each increment in weight. Carcass lean content increased up to 90kg live EOP 4939.doc 4 25/10/2005 weight then reached a plateau and declined after 110kg live weight. Heavier carcasses yielded more product for approximately the same slaughtering cost and the associated larger muscles could make it easier to use seam butchery techniques that result in lean, well-trimmed, attractive cuts and joints. The pH45 and pH24 were reduced with increasing slaughter weight and drip loss increased. Heavier pigs may be more prone to the development of PSE than lighter pigs as their carcass temperature remains higher for longer than that of lighter pigs

Studies on growth rates in pigs and the effect of birth weight

End of project reportThe purpose of this study was to assess some environmental and management factors that affect growth performance on commercial pig units. In experiment 1, a survey was carried out on 22 pig units of known growth performance in south-west Ireland to compare management factors between those showing poor and good growth rates. Low growth rate appears to be due to the cumulative effect of a combination of factors. Experiment 2 was conducted to determine the effects of providing an additional feeder on performance of weaned piglets. No benefits were recorded. Feed consumed from the additional feeder was a replacement for feed that otherwise would have been consumed from the control hopper feeder. Experiment 3 was designed to determine if pig performance and efficiency of growth were affected by weight at birth and at weaning. Lightweight pigs showed inferior growth performance up to the finisher period. Although they compensated some of the inferior growth towards the time of slaughter, they never reached the weights of the heavy birth-weight animals. Males were either significantly heavier or tended to be heavier than females throughout. There was no significant difference between the sexes in the number of days to slaughter. Light and heavy pigs did not differ in the levels of IGF-1 in their blood plasma; however lightweight pigs had significantly lower IgG preweaning. Experiment 4 aimed to determine whether piglet birth weight influenced growth performance, plasma IGF-1 concentrations and muscle fibre characteristics at day 42 of life. At slaughter (Day 42) light birth weight pigs were significantly (P < 0.001) lighter. Plasma IGF-1 concentration was lower by 28% (P=0.06) in light pigs. Muscle fibre cross sectional area and total fibre number were not significantly different between groups. This study should be repeated with bigger numbers

Association of plasma uric acid with ischaemic heart disease and blood pressure: mendelian randomisation analysis of two large cohorts

Objectives: To assess the associations between both uric acid levels and hyperuricaemia, with ischaemic heart disease and blood pressure, and to explore the potentially confounding role of body mass index. Design: Mendelian randomisation analysis, using variation at specific genes (SLC2A9 (rs7442295) as an instrument for uric acid; and FTO (rs9939609), MC4R (rs17782313), and TMEM18 (rs6548238) for body mass index). Setting: Two large, prospective cohort studies in Denmark. Participants: We measured levels of uric acid and related covariables in 58 072 participants from the Copenhagen General Population Study and 10 602 from the Copenhagen City Heart Study, comprising 4890 and 2282 cases of ischaemic heart disease, respectively. Main outcome: Blood pressure and prospectively assessed ischaemic heart disease. Results: Estimates confirmed known observational associations between plasma uric acid and hyperuricaemia with risk of ischaemic heart disease and diastolic and systolic blood pressure. However, when using genotypic instruments for uric acid and hyperuricaemia, we saw no evidence for causal associations between uric acid, ischaemic heart disease, and blood pressure. We used genetic instruments to investigate body mass index as a potentially confounding factor in observational associations, and saw a causal effect on uric acid levels. Every four unit increase of body mass index saw a rise in uric acid of 0.03 mmol/L (95% confidence interval 0.02 to 0.04), and an increase in risk of hyperuricaemia of 7.5% (3.9% to 11.1%). Conclusion: By contrast with observational findings, there is no strong evidence for causal associations between uric acid and ischaemic heart disease or blood pressure. However, evidence supports a causal effect between body mass index and uric acid level and hyperuricaemia. This finding strongly suggests body mass index as a confounder in observational associations, and suggests a role for elevated body mass index or obesity in the development of uric acid related conditions

Differences in intestinal size, structure, and function contributing to feed efficiency in broiler chickens reared at geographically distant locations

The contribution of the intestinal tract to differences in residual feed intake (RFI) has been inconclusively studied in chickens so far. It is also not clear if RFI-related differences in intestinal function are similar in chickens raised in different environments. The objective was to investigate differences in nutrient retention, visceral organ size, intestinal morphology, jejunal permeability and expression of genes related to barrier function, and innate immune response in chickens of diverging RFI raised at 2 locations (L1: Austria; L2: UK). The experimental protocol was similar, and the same dietary formulation was fed at the 2 locations. Individual BW and feed intake (FI) of chickens (Cobb 500FF) were recorded from d 7 of life. At 5 wk of life, chickens (L1, n = 157; L2 = 192) were ranked according to their RFI, and low, medium, and high RFI chickens were selected (n = 9/RFI group, sex, and location). RFI values were similar between locations within the same RFI group and increased by 446 and 464 g from low to high RFI in females and males, respectively. Location, but not RFI rank, affected growth, nutrient retention, size of the intestine, and jejunal disaccharidase activity. Chickens from L2 had lower total body weight gain and mucosal enzyme activity but higher nutrient retention and longer intestines than chickens at L1. Parameters determined only at L1 showed increased crypt depth in the duodenum and jejunum and enhanced paracellular permeability in low vs. high RFI females. Jejunal expression of IL1B was lower in low vs. high RFI females at L2, whereas that of TLR4 at L1 and MCT1 at both locations was higher in low vs. high RFI males. Correlation analysis between intestinal parameters and feed efficiency metrics indicated that feed conversion ratio was more correlated to intestinal size and function than was RFI. In conclusion, the rearing environment greatly affected intestinal size and function, thereby contributing to the variation in chicken RFI observed across locations

Intrauterine Growth and Intelligence Within Sibling Pairs: Findings From the Mater-University Study of Pregnancy and its Outcomes

Objective: To examine the association between intrauterine growth and intelligence. Design: Population based birth cohort study of sibling pairs born within a maximum of three years of each other. Setting: Mater-University women and children's hospital, Brisbane, Australia. Participants: 235 (470 children) sibling pairs. Results: Among one randomly selected sibling from each pair verbal comprehension at age 5, general intelligence at age 14, and reading ability at age 14 increased linearly with increasing gestational age and sex standardised birth weight z scores. With adjustment for maternal age, race, and smoking during pregnancy, birth order, family income, and parental education the associations with verbal comprehension at age 5 and general intelligence at age 14 remained, whereas the association with reading ability at age 14 was attenuated to the null. Within sibling pairs, differences in intrauterine growth were positively associated with differences in verbal comprehension at age 5 (test score difference per one unit difference in birth weight z score = 1.52 (0.11 to 3.26)) and general intelligence at age 14 (1.09 (0.01 to 2.18)), but not with reading ability at age 14. Conclusions: Socioeconomic position or other fixed maternal characteristics do not seem to explain the positive association between intrauterine growth and childhood intelligence

Variation in the SLC23A1 gene does not influence cardiometabolic outcomes to the extent expected given its association with L-ascorbic acid

Background: Observational studies showed that circulating l-ascorbic acid (vitamin C) is inversely associated with cardiometabolic traits. However, these studies were susceptible to confounding and reverse causation. Objectives:We assessed the relation between l-ascorbic acid and 10 cardiometabolic traits by using a single nucleotide polymorphism in the solute carrier family 23 member 1 (SLC23A1) gene (rs33972313) associated with circulating l-ascorbic acid concentrations. The observed association between rs33972313 and cardiometabolic outcomes was compared with that expected given the rs33972313-l-ascorbic acid and l-ascorbic acid–outcome associations. Design: A meta-analysis was performed in the following 5 independent studies: the British Women's Heart and Health Study (n = 1833), the MIDSPAN study (n = 1138), the Ten Towns study (n = 1324), the British Regional Heart Study (n = 2521), and the European Prospective Investigation into Cancer (n = 3737). Results: With the use of a meta-analysis of observational estimates, inverse associations were shown between l-ascorbic acid and systolic blood pressure, triglycerides, and the waist-hip ratio [the strongest of which was the waist-hip ratio (−0.13-SD change; 95% CI: −0.20-, −0.07-SD change; P = 0.0001) per SD increase in l-ascorbic acid], and a positive association was shown with high-density lipoprotein (HDL) cholesterol. The variation at rs33972313 was associated with a 0.18-SD (95% CI: 0.10-, 0.25-SD; P = 3.34 × 10−6) increase in l-ascorbic acid per effect allele. There was no evidence of a relation between the variation at rs33972313 and any cardiometabolic outcome. Although observed estimates were not statistically different from expected associations between rs33972313 and cardiometabolic outcomes, estimates for low-density lipoprotein cholesterol, HDL cholesterol, triglycerides, glucose, and body mass index were in the opposite direction to those expected. Conclusions: The nature of the genetic association exploited in this study led to limited statistical application, but despite this, when all cardiometabolic traits were assessed, there was no evidence of any trend supporting a protective role of l-ascorbic acid. In the context of existing work, these results add to the suggestion that observational relations between l-ascorbic acid and cardiometabolic health may be attributable to confounding and reverse causation

Cohort profile: the avon longitudinal study of parents and children: ALSPAC mothers cohort

The Avon Longitudinal Study of Children and Parents (ALSPAC) was established to understand how genetic and environmental characteristics influence health and development in parents and children. All pregnant women resident in a defined area in the South West of England, with an expected date of delivery between 1st April 1991 and 31st December 1992, were eligible and 13 761 women (contributing 13 867 pregnancies) were recruited. These women have been followed over the last 19–22 years and have completed up to 20 questionnaires, have had detailed data abstracted from their medical records and have information on any cancer diagnoses and deaths through record linkage. A follow-up assessment was completed 17–18 years postnatal at which anthropometry, blood pressure, fat, lean and bone mass and carotid intima media thickness were assessed, and a fasting blood sample taken. The second follow-up clinic, which additionally measures cognitive function, physical capability, physical activity (with accelerometer) and wrist bone architecture, is underway and two further assessments with similar measurements will take place over the next 5 years. There is a detailed biobank that includes DNA, with genome-wide data available on &gt;10 000, stored serum and plasma taken repeatedly since pregnancy and other samples; a wide range of data on completed biospecimen assays are available. Details of how to access these data are provided in this cohort profile

Measurements of the acid-binding capacity of ingredients used in pig diets

peer-reviewedSome feed ingredients bind more acid in the stomach than others and for this reason may be best omitted from pig starter foods if gastric acidity is to be promoted. The objective of this study was to measure the acid-binding capacity (ABC) of ingredients commonly used in pig starter foods. Ingredients were categorised as follows: (i) milk products (n = 6), (ii) cereals (n = 10), (iii) root and pulp products (n = 5), (iv) vegetable proteins (n = 11), (v) meat and fish meal (n = 2), (vi) medication (n = 3), (vii) amino acids (n = 4), (viii) minerals (n = 16), (ix) acid salts (n = 4), (x) acids (n = 10). A 0.5 g sample of food was suspended in 50 ml distilled de-ionised water with continuous stirring. This suspension was titrated with 0.1 mol/L HCl or 0.1 mol/L NaOH so that approximately 10 additions of titrant was required to reach pH 3.0. The pH readings after each addition were recorded following equilibration for three minutes. ABC was calculated as the amount of acid in milliequivalents (meq) required to lower the pH of 1 kg food to (a) pH 4.0 (ABC-4) and (b) pH 3.0 (ABC-3). Categories of food had significantly different (P < 0.01) ABC values. Mean ABC-4 and ABC-3 values of the ten categories were: (i) 623 (s.d. 367.0) and 936 (s.d. 460.2), (ii) 142 (s.d. 79.2) and 324 (s.d. 146.4), (iii) 368 (s.d. 65.3) and 804 (s.d. 126.7), (iv) 381 (s.d. 186.1) and 746 (s.d. 227.0), (v) 749 (s.d. 211.6) and 1508 (s.d. 360.8), (vi) 120 (s.d. 95.6) and 261 (s.d. 163.2), (vii) 177 (s.d. 60.7) and 1078 (s.d. 359.0), (viii) 5064 (s.d. 5525.1) and 7051 (s.d. 5911.6), (ix) 5057 (s.d. 1336.6) and 8945 (s.d. 2654.1) and (x) -5883 (s.d. 4220.5) and -2591 (s.d. 2245.4) meq HCl per kg, respectively. Within category, ABC-3 and ABC- 4 values were highly correlated: R2 values of 0.80 and greater for food categories i, iv, v, vi, vii and viii. The correlation between predicted and observed ABC values of 34 mixed diets was 0.83 for ABC-4 and 0.71 for ABC-3. It was concluded that complete diets with low ABC values may be formulated through careful selection of ingredients. The final pH to which ABC is measured should matter little as ABC-3 and ABC-4 are highly correlated