Breeding and genetics
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Gene expression in Sinclair swine with malignant melanoma
- M. Okomo-Adhiambo, A. Rink, W. M. Rauw, L. Gomez-Raya
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- Published online by Cambridge University Press:
- 22 September 2011, pp. 179-192
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Sinclair swine develop an aggressive form of melanoma, which, in many cases, spontaneously regresses after a complete metastatic phase. We used Affymetrix GeneChip® Porcine Genome Arrays consisting of 24 123 probe sets to compare gene expression in white blood cells (WBCs) and various tissues including the liver, lungs, inguinal lymph nodes and spleen harvested from a Sinclair piglet afflicted by melanoma at birth and exhibiting metastatic lesions at weaning (6 weeks) with those from a full-sibling piglet that showed no incidence of melanoma at birth and weaning. The highest number (3489; ∼14%) of significantly upregulated transcripts (fold change in gene expression ⩾2.0 and t-test P-value ≤0.05) was observed in the liver, while the spleen exhibited the lowest number of upregulated transcripts (528; ∼2%). Among significantly downregulated genes, the highest numbers were observed in the inguinal lymph nodes (3651; ∼15%) and the least in WBCs (730; ∼3%). Differentially expressed transcripts included genes involved in melanoma pathogenesis including SILV, TYR and RAB28. SILV was over-expressed 784-, 430- and 164-fold, while TYR was over-expressed 138-, 81- and 28-fold in the liver, lungs and inguinal lymph nodes, respectively. Quantitative real-time RT-PCR (qRT-PCR) confirmed the microarray data of 12 selected differentially expressed sequences. These results suggest that significant changes in gene expression occur during metastasis of malignant melanoma in the Sinclair swine model. In addition, qRT-PCR analysis of the above 12 differentially expressed sequences was carried out on liver samples collected from 22 pigs (12 of which had melanoma during the first 6 weeks of life), and an ANOVA test contrasting absolute RNA expression between pigs with regressing, progressing and without tumors was significant for TYR, TACSTD1, MATP, GPNMB and CYP4A22, with P-values of 0.034, 0.015, 0.007, 0.050 and 0.022, respectively.
A simple method for genomic selection of moderately sized dairy cattle populations
- J. I. Weller, M. Ron, G. Glick, A. Shirak, Y. Zeron, E. Ezra
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- Published online by Cambridge University Press:
- 26 September 2011, pp. 193-202
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An efficient algorithm for genomic selection of moderately sized populations based on single nucleotide polymorphism chip technology is described. A total of 995 Israeli Holstein bulls with genetic evaluations based on daughter records were genotyped for either the BovineSNP50 BeadChip or the BovineSNP50 v2 BeadChip. Milk, fat, protein, somatic cell score, female fertility, milk production persistency and herd-life were analyzed. The 400 markers with the greatest effects on each trait were first selected based on individual analysis of each marker with the genetic evaluations of the bulls as the dependent variable. The effects of all 400 markers were estimated jointly using a ‘cow model,’ estimated from the data truncated to exclude lactations with freshening dates after September 2006. Genotype probabilities for each locus were computed for all animals with missing genotypes. In Method I, genetic evaluations were computed by analysis of the truncated data set with the sum of the marker effects subtracted from each record. Genomic estimated breeding values for the young bulls with genotypes, but without daughter records, were then computed as their parent averages combined with the sum of each animal's marker effects. Method II genomic breeding values were computed based on regressions of estimated breeding values of bulls with daughter record on their parent averages, sum of marker effects and birth year. Method II correlations of the current breeding values of young bulls without daughter records in the truncated data set were higher than the correlations of the current breeding values with the parent averages for fat and protein production, persistency and herd-life. Bias of evaluations, estimated as a difference between the mean of current breeding values of the young bulls and their genomic evaluations, was reduced for milk production traits, persistency and herd-life. Bias for milk production traits was slightly negative, as opposed to the positive bias of parent averages. Correlations of Method II with the means of daughter records adjusted for fixed effects were higher than parent averages for fat, protein, fertility, persistency and herd-life. Reducing the number of markers included in the analysis from 400 to 300 did not reduce correlations of genomic breeding values for protein with current breeding values, but did slightly reduce correlations with means of daughter records. Method II has the advantages as compared with the method of VanRaden in that genotypes of cows can be readily incorporated into the Method II analysis, and it is more effective for moderately sized populations.
Assessing priorities for conservation in Tuscan cattle breeds using microsatellites
- R. Bozzi, I. Álvarez, A. Crovetti, I. Fernández, D. De Petris, F. Goyache
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- Published online by Cambridge University Press:
- 22 August 2011, pp. 203-211
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Preservation of rare genetic stocks requires assessment of within-population genetic diversity and between-population differentiation to make inferences on their degree of uniqueness. A total of 194 Tuscan cattle (44 Calvana, 35 Chianina, 25 Garfagnina, 31 Maremmana, 31 Mucca Pisana and 28 Pontremolese) individuals were genotyped for 34 microsatellite markers. Moreover, 56 samples belonging to Argentinean Creole and Asturiana de la Montaña cattle breeds were used as an outgroup. Genetic diversity was quantified in terms of molecular coancestry and allelic richness. STRUCTURE analyses showed that the Tuscan breeds have well-differentiated genetic backgrounds, except for the Calvana and Chianina breeds, which share the same genetic ancestry. The between-breed Nei's minimum distance (Dm) matrices showed that the pair Calvana–Chianina was less differentiated (0.049 ± 0.006). The endangered Tuscan breeds (Calvana, Garfagnina, Mucca Pisana and Pontremolese) made null or negative contributions to diversity, except for the Mucca Pisana contribution to allelic richness (CT = 1.8%). The Calvana breed made null or negative within-breed contributions (W = 0.0%; CW = −0.4%). The Garfagnina and Pontremolese breeds made positive contributions to between-breed diversity but negative and high within-breed contributions, thus suggesting population bottleneck with allelic losses and increase of homozygosity in the population. Exclusion of the four endangered Tuscan cattle breeds did not result in losses in genetic diversity (T = −0.7%; CT = −1.2%), whereas exclusion of the non-endangered breeds (Chianina and Maremmana) did (T = 2.1%; CT = 3.9%); the simple exclusion of the Calvana breed from the former group led to losses in genetic diversity (T = 0.47%; CT = 2.34%), indicating a diverse significance for this breed. We showed how quantifying both within-population diversity and between-population differentiation in terms of allelic frequencies and allelic richness provides different and complementary information on the genetic backgrounds assessed and may help to implement priorities and strategies for conservation in livestock.
Random regression analyses using B-spline functions to model growth of Nellore cattle
- A. A. Boligon, M. E. Z. Mercadante, R. B. Lôbo, F. Baldi, L. G. Albuquerque
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- Published online by Cambridge University Press:
- 12 September 2011, pp. 212-220
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The objective of this study was to estimate (co)variance components using random regression on B-spline functions to weight records obtained from birth to adulthood. A total of 82 064 weight records of 8145 females obtained from the data bank of the Nellore Breeding Program (PMGRN/Nellore Brazil) which started in 1987, were used. The models included direct additive and maternal genetic effects and animal and maternal permanent environmental effects as random. Contemporary group and dam age at calving (linear and quadratic effect) were included as fixed effects, and orthogonal Legendre polynomials of age (cubic regression) were considered as random covariate. The random effects were modeled using B-spline functions considering linear, quadratic and cubic polynomials for each individual segment. Residual variances were grouped in five age classes. Direct additive genetic and animal permanent environmental effects were modeled using up to seven knots (six segments). A single segment with two knots at the end points of the curve was used for the estimation of maternal genetic and maternal permanent environmental effects. A total of 15 models were studied, with the number of parameters ranging from 17 to 81. The models that used B-splines were compared with multi-trait analyses with nine weight traits and to a random regression model that used orthogonal Legendre polynomials. A model fitting quadratic B-splines, with four knots or three segments for direct additive genetic effect and animal permanent environmental effect and two knots for maternal additive genetic effect and maternal permanent environmental effect, was the most appropriate and parsimonious model to describe the covariance structure of the data. Selection for higher weight, such as at young ages, should be performed taking into account an increase in mature cow weight. Particularly, this is important in most of Nellore beef cattle production systems, where the cow herd is maintained on range conditions. There is limited modification of the growth curve of Nellore cattle with respect to the aim of selecting them for rapid growth at young ages while maintaining constant adult weight.
Nutrition
Full Paper
Fe bioavailability from Fe-enriched yeast biomass in growing rats
- T. Pirman, A. Orešnik
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- Published online by Cambridge University Press:
- 19 September 2011, pp. 221-226
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The Fe content in animal feeds is highly variable. The availability of Fe in feeds varies with the feed and the form in which Fe is present. The present study reports the effect of the addition of different concentrations of Fe from yeast biomass on Fe bioavailability and Fe level in rat liver, compared with a diet containing Fe-sulphate (Fe-sulphate) addition (control) and with a diet without any addition of Fe. Male Wistar rats were fed ad libitum for 10 days a diet with different levels of Fe-enriched yeast biomass (20, 35 and 50 mg of Fe), or Fe-sulphate diet (50 mg of Fe) or without Fe addition. Faeces and urine were collected for Fe analyses during the last 5 days of the test period. The results clearly showed a highly significant (P < 0.001) better bioavailability of Fe from Fe-enriched yeast biomass, independent of the level of Fe in the diet. This was on average 36% higher than the availability of Fe from the Fe-sulphate-enriched diet. Liver Fe storage depended on the level of Fe in the diet from yeast biomass. A significantly lower amount of Fe was found to be incorporated in the liver in the group with an inorganic source of Fe (Fe-sulphate) in the diet.
Apparent digestibility of wheat bran and extruded flax in horses determined from the total collection of feces and acid-insoluble ash as an internal marker
- M. De Marco, N. Miraglia, P. G. Peiretti, D. Bergero
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- Published online by Cambridge University Press:
- 22 August 2011, pp. 227-231
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Several studies have reported data on comparisons between two methods: the total collection of feces and the internal markers method. The aim of this study was to assess the apparent digestibility of two concentrates and to compare the apparent digestion coefficients using the total collection of feces and acid-insoluble ash (AIA) as the internal marker method. In 2009, six adult geldings aged between 3 and 11 years, with an average weight per trial of 543, 540 and 542 kg, respectively, were used to determine the apparent digestibility by means of three in vivo digestibility trials on hay, hay plus wheat bran (60 : 40) and hay plus extruded flax (80 : 20). Feces were collected over a 6-day period with a previous 14-day adaptation period. The three digestibility trials were carried out to determine the digestion coefficients of the three diets and, indirectly, of the two concentrates. The digestion coefficients of the diets were determined for the dry matter, organic matter, crude protein and gross energy, whereas the apparent digestion coefficients of the same parameters were calculated for wheat bran and extruded flax, by calculating the difference from the previous results. The data were analyzed using the Student t-test for paired samples. The digestion coefficients obtained were similar when the total collection of feces and the AIA method were used. Higher data variability, confirmed by a greater standard deviation, was observed using the AIA method to estimate the apparent digestion coefficients. It can be concluded that the use of AIA as an internal marker in digestibility trials on average leads to values similar to those obtained with the total collection of feces and can therefore be considered a less-expensive method to determine apparent digestion coefficients. Nevertheless, the total collection of feces should still be considered the best choice to determine the digestibility of some specific feedstuffs.
N-alkanes v. ytterbium/faecal index as two methods for estimating herbage intake of dairy cows fed on diets differing in the herbage : maize silage ratio and feeding level
- E. Pérez-Ramírez, J. L. Peyraud, R. Delagarde
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- Published online by Cambridge University Press:
- 30 August 2011, pp. 232-244
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The aim of this study was to compare the n-alkanes and the ytterbium (Yb)/faecal index techniques as two methods for estimating the herbage intake of dairy cows fed indoors on different herbage : supplement ratios and feeding levels. The supplement was a mixture of maize silage and soyabean meal (ratio of 87 : 13 on a dry matter (DM) basis). In all, four treatments were studied. The herbage : supplement ratio in the diet was 25 : 75, 50 : 50, 75 : 25 and 50 : 50 for treatments 1, 2, 3 and 4, respectively. Animals were offered for treatments 1, 2 and 3, 100% of ad libitum intake measured before the experiment and 70% of ad libitum intake for treatment 4. Cows were fed herbage in the morning and supplement in the evening. A total of six lactating Holstein dairy cows were used in a 4 × 4 Latin square with four 14-day periods. Herbage and supplement intakes, faecal output (FO), in vivo organic matter (OM) digestibility and faecal recovery of markers were measured on the last 5 days of each period. Intake was estimated with the two methods and from two faecal sampling techniques, that is, total faecal collection v. grab sampling during milking. Mean herbage intake as fed, or estimated from n-alkanes or from the Yb/faecal index was 7.7, 8.1 and 10.2 kg DM, respectively. The mean prediction error, expressed as a fraction of actual herbage intake, was 0.10 and 0.50 for the n-alkanes and Yb/faecal index methods, respectively. The n-alkanes method clearly showed much better accuracy than the Yb/faecal index method for estimating intake, irrespective of the faecal sampling method, herbage : silage proportion or feeding level. For the n-alkanes method, herbage intake was slightly overestimated (7%) when herbage proportion in the diet was high, due to a ratio of faecal C33 : C32 recovery >1. The high bias for the Yb/faecal index was due to the cumulative effect of overestimation of FO (mean recovery of Yb = 0.92) and underestimation of the diet indigestible fraction (−8%). Between-treatment variations of FO were on average well estimated by Yb. Between-treatment variations of OM digestibility estimated using the faecal index technique were lower than those observed in vivo. It is concluded that intake of grazing dairy cows receiving high levels of maize silage supplement should be estimated using the n-alkanes method.
Effects of condensed tannins in wrapped silage bales of sainfoin (Onobrychis viciifolia) on in vivo and in situ digestion in sheep
- K. Theodoridou, J. Aufrère, D. Andueza, A. Le Morvan, F. Picard, J. Pourrat, R. Baumont
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- Published online by Cambridge University Press:
- 07 September 2011, pp. 245-253
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The objective of this study was to characterize the condensed tannins (CTs) in wrapped silage bales of sainfoin (Onobrychis viciifolia) and examine their potential action on in vivo and in situ digestive characteristics in sheep. Silage was made from sainfoin, cut at two phenological stages. The first phenological stage, at which silage was made, was from the first vegetation cycle at the end of flowering and the second stage silage was made from regrowth, 5 weeks after the first cut, but before flowering. The silages made from the two phenological stages were fed to 12 rumen-fistulated sheep in a crossover design. Of the 12 sheep, six received polyethylene glycol (PEG) to bind with and remove the effects of CT, whereas the other six were dosed with water. Organic matter digestibility, total-tract N digestibility and N (N) balance were measured over 6 days. Kinetic studies were performed on total N, ammonia N (NH3-N) and volatile fatty acids (VFAs) in rumen fluid before and 1.5, 3 and 6 h after feeding. The kinetics of degradation of dry matter and N from Dacron bags suspended in the rumen were also determined. Biological activity of CT (protein-binding capacity) and CT concentration were greater for the silage made from sainfoin at the early flowering stage. Total-tract N digestibility was increased by the addition of PEG (P < 0.001) to the sainfoin silage before flowering (P < 0.001). CTs decreased N excretion in urine (P < 0.05) and increased faecal N excretion (P < 0.001), but had no effect on body N retention, which is beneficial for the animal. Ruminal N degradability was smaller in the presence of active CT (P < 0.001) at both phenological stages; however, soluble N (P = 0.2060) and NH3-N (P = 0.5225) concentrations in rumen fluid remained unchanged. The results of this experiment indicate that CT in the sainfoin retain their ability to affect the nutritive value of preserved forage legumes.
Physiology and functional biology of systems
Full Paper
Metabolic regulation of fatty acid esterification and effects of conjugated linoleic acid on glucose homeostasis in pig hepatocytes
- J. A. Conde-Aguilera, M. Lachica, R. Nieto, I. Fernández-Fígares
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- Published online by Cambridge University Press:
- 22 September 2011, pp. 254-261
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Conjugated linoleic acids (CLAs) are geometric and positional isomers of linoleic acid (LA) that promote growth, alter glucose metabolism and decrease body fat in growing animals, although the mechanisms are poorly understood. A study was conducted to elucidate the effects of CLA on glucose metabolism, triglyceride (TG) synthesis and IGF-1 synthesis in primary culture of porcine hepatocytes. In addition, hormonal regulation of TG and IGF-1 synthesis was addressed. Hepatocytes were isolated from piglets (n = 5, 16.0 ± 1.98 kg average body weight) by collagenase perfusion and seeded into collagen-coated T-25 flasks. Hepatocytes were cultured in William's E containing dexamethasone (10−8 and 10−7 M), insulin (10 and 100 ng/ml), glucagon (0 and 100 ng/ml) and CLA (1 : 1 mixture of cis-9, trans-11 and trans-10, cis-12 CLA, 0.05 and 0.10 mM) or LA (0.05 and 0.10 mM). Addition of CLA decreased gluconeogenesis (P < 0.05), whereas glycogen synthesis and degradation, TG synthesis and IGF-1 synthesis were not affected compared with LA. Increased concentration of fatty acids in the media decreased IGF-1 production (P < 0.001) and glycogen synthesis (P < 0.01), and increased gluconeogenesis (P < 0.001) and TG synthesis (P < 0.001). IGF-1 synthesis increased (P < 0.001) and TG synthesis decreased (P < 0.001) as dexamethasone concentration in the media rose. High insulin/glucagon increased TG synthesis. These results indicate that TG synthesis in porcine hepatocytes is hormonally regulated so that dexamethasone decreases and insulin/glucagon increases it. In addition, CLA decreases hepatic glucose production through decreased gluconeogenesis.
Linoleic and α-linolenic acid as precursor and inhibitor for the synthesis of long-chain polyunsaturated fatty acids in liver and brain of growing pigs
- W. Smink, W. J. J. Gerrits, M. Gloaguen, A. Ruiter, J. van Baal
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- Published online by Cambridge University Press:
- 07 September 2011, pp. 262-270
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Studies suggested that in human adults, linoleic acid (LA) inhibits the biosynthesis of n-3 long-chain polyunsaturated fatty acids (LC-PUFA), but their effects in growing subjects are largely unknown. We used growing pigs as a model to investigate whether high LA intake affects the conversion of n-3 LC-PUFA by determining fatty acid composition and mRNA levels of Δ5- and Δ6 desaturase and elongase 2 and -5 in liver and brain. In a 2 × 2 factorial arrangement, 32 gilts from eight litters were assigned to one of the four dietary treatments, varying in LA and α-linolenic acid (ALA) intakes. Low ALA and LA intakes were 0.15 and 1.31, and high ALA and LA intakes were 1.48 and 2.65 g/kg BW0.75 per day, respectively. LA intake increased arachidonic acid (ARA) in liver. ALA intake increased eicosapentaenoic acid (EPA) concentrations, but decreased docosahexaenoic acid (DHA) (all P < 0.01) in liver. Competition between the n-3 and n-6 LC-PUFA biosynthetic pathways was evidenced by reductions of ARA (>40%) at high ALA intakes. Concentration of EPA (>35%) and DHA (>20%) was decreased by high LA intake (all P < 0.001). Liver mRNA levels of Δ5- and Δ6 desaturase were increased by LA, and that of elongase 2 by both ALA and LA intakes. In contrast, brain DHA was virtually unaffected by dietary LA and ALA. Generally, dietary LA inhibited the biosynthesis of n-3 LC-PUFA in liver. ALA strongly affects the conversion of both hepatic n-3 and n-6 LC-PUFA. DHA levels in brain were irresponsive to these diets. Apart from Δ6 desaturase, elongase 2 may be a rate-limiting enzyme in the formation of DHA.
Expression and activities of hepatic cytochrome P450 (CYP1A, CYP2A and CYP2E1) in entire and castrated male pigs
- C. Brunius, M. K. Rasmussen, H. Lacoutière, K. Andersson, B. Ekstrand, G. Zamaratskaia
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- Published online by Cambridge University Press:
- 22 September 2011, pp. 271-277
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This study aimed to provide further insights into the mechanism of in vivo regulation of cytochrome P450 (CYP450) 1A, 2A and 2E1 activities in pigs with different levels of testicular steroids. Hepatic mRNA and protein expression and enzymatic activity of CYP1A, CYP2A and CYP2E1 were compared between entire male and castrated pigs. Castration was performed either surgically or immunologically. The pigs were divided into four groups. In the first group, piglets were surgically castrated without anaesthesia. Immunological castration was performed by vaccination with Improvac® (Pfizer Ltd). Vaccinated pigs were subdivided into two groups according to the vaccination regimen: early and standard vaccination. Pigs in the early vaccination group were vaccinated when aged 11 and 15 weeks. Pigs in the standard vaccination group were vaccinated when aged 17 and 21 weeks. In the control group, pigs remained intact throughout the study. Hepatic CYP450 mRNA expression, measured by real-time RT-PCR, differed significantly between groups for all isoforms measured: CYP1A2 (P = 0.002), 2A (P = 0.000) and 2E1 (P = 0.002). Lower CYP450 mRNA in entire male pigs suggests suppression of CYP1A2, CYP2A and CYP2E1 by testicular steroids at the transcriptional level. However, this suppression was not always reflected in decreased protein expression and activities of these isoforms, suggesting that at least some CYP450s (e.g. CYP2E1) are regulated by a post-transcriptional mechanism.
Fusarium mycotoxin-contaminated wheat containing deoxynivalenol alters the gene expression in the liver and the jejunum of broilers
- B. Dietrich, S. Neuenschwander, B. Bucher, C. Wenk
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- Published online by Cambridge University Press:
- 19 September 2011, pp. 278-291
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The effects of mycotoxins in the production of animal feed were investigated using broiler chickens. For the feeding trial, naturally Fusarium mycotoxin-contaminated wheat was used, which mainly contained deoxynivalenol (DON). The main effects of DON are reduction of the feed intake and reduced weight gain of broilers. At the molecular level, DON binds to the 60 S ribosomal subunit and subsequently inhibits protein synthesis at the translational level. However, little is known about other effects of DON, for example, at the transcriptional level. Therefore, a microarray analysis was performed, which allows the investigation of thousands of transcripts in one experiment. In the experiment, 20 broilers were separated into four groups of five broilers each at day 1 after hatching. The diets consisted of a control diet and three diets with calculated, moderate concentrations of 1.0, 2.5 and 5.0 mg DON/kg feed, which was attained by exchanging uncontaminated wheat with naturally mycotoxin-contaminated wheat up to the intended DON concentration. The broilers were held at standard conditions for 23 days. Three microarrays were used per group to determine the significant alterations of the gene expression in the liver (P < 0.05), and qPCR was performed on the liver and the jejunum to verify the results. No significant difference in BW, feed intake or feed conversion rate was observed. The nutrient uptake into the hepatic and jejunal cells seemed to be influenced by genes: SLC2A5 (fc: −1.54, DON2.5), which facilitates glucose and fructose transport and SLC7A10 (fc: +1.49, DON5), a transporter of d-serine and other neutral amino acids. In the jejunum, the palmitate transport might be altered by SLC27A4 (fc: −1.87, DON5) and monocarboxylates uptake by SLC16A1 (fc: −1.47, DON5). The alterations of the SLC gene expression may explain the reduced weight gain of broilers chronically exposed to DON-contaminated wheat. The decreased expressions of EIF2AK3 (fc: −1.29, DON2.5/5) and DNAJC3 (fc: −1.44, DON2.5) seem to be related to the translation inhibition. The binding of DON to the 60 S ribosomal subunit and the subsequent translation inhibition might be counterbalanced by the downregulation of EIF2AK3 and DNAJC3. The genes PARP1, MPG, EME1, XPAC, RIF1 and CHAF1B are mainly related to single-strand DNA modifications and showed an increased expression in the group with 5 mg DON/kg feed. The results indicate that significantly altered gene expression was already occurring at 2.5 mg DON/kg feed.
Nutritional regulation of body condition score at the initiation of the transition period in primiparous and multiparous dairy cows under grazing conditions: milk production, resumption of post-partum ovarian cyclicity and metabolic parameters
- M. L. Adrien, D. A. Mattiauda, V. Artegoitia, M. Carriquiry, G. Motta, O. Bentancur, A. Meikle
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- Published online by Cambridge University Press:
- 22 August 2011, pp. 292-299
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The objective of this study was to investigate the effect of different body condition score (BCS) at 30 days before calving (−30 days) induced by a differential nutritional management from −100 days until −30 days on productive parameters, the interval to first ovulation and blood parameters in primiparous and multiparous Holstein cows under grazing conditions until 60 days post partum. The experimental arrangement was a randomized complete block design, where cows were blocked according to BW and expected calving date and then randomly assigned to different nutritional treatments from –100 to –30 days relative to calving to induce different BCS. As the assignment of cows to treatments was random, cows had to lose, maintain or gain BCS; thus, different planes of nutrition were offered with approximately 7, 14 or 20 kg dry matter per day. The BCS score was assessed every 15 days and animals were reassigned in order to achieve the desired BCS at –30 days. Only animals that responded to nutritional treatment were considered and this was defined as follows: primiparous and multiparous high cows (PH and MH) had to gain 0.5 points of BCS, primiparous low (PL) had to lose 0.5 points of BCS and multiparous low (ML) had to maintain BCS at least in two subsequent observations from −100 to −30 days. From −30 days to calving, primiparous and multiparous cows (P and M cows) were managed separately and cows were offered a diet once a day. From calving to 60 days post partum, cows of different groups grazed in separate plots a second year pasture. Cows were also supplemented individually with whole-plant maize silage and commercial concentrate. Cows had similar BCS at −100 days and differed after the nutritional treatment; however, all groups presented similar BCS at 21 days post partum. The daily milk production and milk yield at 60 days post partum was higher in M than P cows. The percentage of milk fat was higher in PH cows compared with PL cows. Concentrations of non-esterified fatty acids (NEFA) were affected by the BCS at −30 days within parity, and in PH cows the concentration of NEFA was higher than in PL cows. The concentrations of total protein were higher in M cows. A lower probability of cycling was found in PL than in PH cows (P < 0.05) and in ML than in MH cows (P < 0.05). Treatment affected various endocrine/metabolic profiles according to parity, suggesting that the metabolic reserves signal the productive/reproductive axis so as to induce a differential nutrient partitioning in adult v. first-calving cows.
Effects of propylene glycol drenching before and after luteolysis on blood glucose, ovarian steroids and follicular dynamics in heifers
- A. Umeki, T. Tanaka, H. Kamomae
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- Published online by Cambridge University Press:
- 07 September 2011, pp. 300-304
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The effect of propylene glycol drenching on ovarian and hormonal dynamics was studied in heifers. Five cycling heifers were used twice (as control and treatment) with crossover design. After the confirmation of ovulation (day 0), the heifers in the treatment group received propylene glycol on days 6, 7 and 8 as an oral drench (250 ml of 90% propylene glycol). On day 10, prostaglandin F2α (PGF2α), 15 mg per head of dinoprost, was administered intramuscularly to induce luteal regression followed by the follicular phase and then propylene glycol was again administered twice daily (500 ml/day) on days 10, 11 and 12. Palpation per rectum and ovarian ultrasonography were performed every other day from days 0 to 10, and daily after PGF2α administration until the subsequent ovulation (second ovulation) for analysis of follicular and luteal dynamics. Blood samples were also collected every other day from days 0 to 10, and then at 6 h intervals after PGF2α administration until the second ovulation. For the samples taken at 6-h intervals after PGF2α administration, the concentrations of glucose showed clear daily fluctuations in both groups. Changes in the plasma concentration of glucose in the treatment group were significantly (P < 0.05) higher than those of the control groups during the period between 0 and 72 h after PGF2α administration. No significant difference was detected in the growth of dominant follicles, maximum diameter of the ovulatory follicles and the changes in oestradiol and progesterone during the follicular phase between treatment and control groups. This study showed the clear daily fluctuations and stimulatory changes in the blood glucose concentrations at 24-h intervals during the short-term treatment of propylene glycol drenching in heifers. However, no significant changes in ovarian and hormonal dynamics were found under such metabolic conditions.
Behaviour, welfare and health
Full Paper
Evaluation of chronic immune system stimulation models in growing pigs
- A. Rakhshandeh, C. F. M. de Lange
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- Published online by Cambridge University Press:
- 08 September 2011, pp. 305-310
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Two experiments (EXPs) were conducted to evaluate models of immune system stimulation (ISS) that can be used in nutrient metabolism studies in growing pigs. In EXP I, the pig's immune response to three non-pathogenic immunogens was evaluated, whereas in EXP II the pig's more general response to one of the immunogens was contrasted with observations on non-ISS pigs. In EXP I, nine growing barrows were fitted with a jugular catheter, and after recovery assigned to one of three treatments. Three immunogens were tested during a 10-day ISS period: (i) repeated injection of increasing amounts of Escherichiacoli lipopolysaccharide (LPS); (ii) repeated subcutaneous injection of turpentine (TURP); and (iii) feeding grains naturally contaminated with mycotoxins (MYCO). In EXP II, 36 growing barrows were injected repeatedly with either saline (n = 12) or increasing amounts of LPS (n = 24) for 7 days (initial dose 60 μg/kg body weight). Treating pigs with TURP and LPS reduced feed intake (P < 0.02), whereas feed intake was not reduced in pigs on MYCO. Average daily gain (ADG; kg/day) of pigs on LPS (0.50) was higher than that of pigs on TURP (0.19), but lower than that of pigs on MYCO (0.61; P < 0.01). Body temperature was elevated in pigs on LPS and TURP, by 0.8°C and 0.7°C, respectively, relative to pre-ISS challenge values (39.3°C; P < 0.02), but remained unchanged in pigs on MYCO. Plasma concentrations of interleukin-1β were increased in pigs treated with LPS and TURP (56% and 55%, respectively, relative to 22.3 pg/ml for pre-ISS; P < 0.01), but not in MYCO-treated pigs. Plasma cortisol concentrations remained unchanged for pigs on MYCO and TURP, but were reduced in LPS-treated pigs (30% relative to 29.8 ng/ml for pre-ISS; P < 0.05). Red blood cell glutathione concentrations were lower in TURP-treated pigs (13% relative to 1.38 μM for pre-ISS; P < 0.05), but were unaffected in pigs on LPS and MYCO. In EXP I, TURP caused severe responses including skin ulceration and substantial reductions in feed intake and ADG, whereas MYCO did not induce effective ISS. In EXP II, ISS increased relative organ weights, eye temperature, white blood cell count and plasma acute-phase proteins (P < 0.05), confirming that repeated injection with increasing amounts of LPS induced chronic and relatively mild ISS. Repeated injection with increasing amounts of LPS is a suitable model for studying nutrient metabolism and evaluating the efficacy of nutritional intervention during chronic ISS in growing pigs.
Coronary angiography and percutaneous coronary intervention in the porcine model: a practical guide to the procedure
- P. D. Williams, N. Malik, P. A. Kingston
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- Published online by Cambridge University Press:
- 20 September 2011, pp. 311-320
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Assessment of safety and efficacy within the porcine coronary artery model remains a standard requirement for new therapies delivered to the coronary arteries before proceeding to clinical testing. Human coronary procedures carry a very low mortality rate; however, procedural mortality for porcine experiments is often high, despite these animals being young and free of atherosclerosis. Some of these deaths are due to poor technique, and therefore avoidable. However, despite the wide use of this model, a systematic description of the procedure has never been published. This article will detail how porcine angiography and stent implantation is performed in our institution and will discuss the relevant differences between humans and pigs with regard to anaesthesia, pharmacotherapy, vascular access, catheter selection and angiographic views. Important variations to the technique that have been reported are also covered.
Longitudinal analysis of acute-phase proteins in saliva in pig farms with different health status
- A. M. Gutiérrez, J. J. Cerón, P. Fuentes, A. Montes, S. Martínez-Subiela
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- Published online by Cambridge University Press:
- 20 September 2011, pp. 321-326
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This study assesses the utility of saliva samples to monitor the time course of the acute-phase response to different viruses in pigs under field conditions by using time-resolved immunofluorometric assays (TR-IFMA). A total of 30 pigs from three different farms, located in Southeast Spain, were used. Farm 1 had outbreaks of porcine circovirus type 2, farm 2 had infections with porcine reproductive and respiratory syndrome virus and farm 3 had concomitant infections with both viruses. Serology was used to determine the time of seroconversion of pigs to two different pathogens. The levels of two acute-phase proteins (APPs), C-reactive protein (CRP) and haptoglobin (Hp), were measured in saliva and serum samples and compared with pig's serology. Kinetic curves of both APPs across the study obtained in saliva samples were similar to those of serum, with R of 0.68 and 0.78 for CRP and Hp, respectively. The median CRP and Hp concentrations in saliva were higher around the theorized time of infection, according to previous experimental studies, and at seroconversion of animals. CRP increments were apparent 1 week before the increments obtained in Hp. These findings indicate that salivary APP concentrations, by using TR-IFMA, can be used in longitudinal studies as non-invasive early indicators of health status.
Product quality, human health and well-being
Review
Factors in pig production that impact the quality of dry-cured ham: a review
- M. Čandek-Potokar, M. Škrlep
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- Published online by Cambridge University Press:
- 19 September 2011, pp. 327-338
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This study reviews the factors of pig production that impact the quality of dry-cured ham. When processing is standardized, the quality of the final dry-cured product is primarily determined by the quality of the meat before curing (green ham). This has been defined as the aptitude for seasoning and is determined by the green ham weight, adipose tissue quantity and quality, meat physico-chemical properties and the absence of visual defects. Various ante-mortem factors including pig age and weight, genetic type, diet, feeding strategy and slaughter conditions determine green ham properties such as the dynamics of water loss, salt intake and, as a consequence, proteolysis and lipolysis. Muscle conditions (pH, salt concentration, water content and availability, temperature) influence enzymatic activity and development of characteristic texture and flavor. Generally, hams of older and heavier pigs present better seasoning aptitude because of higher adiposity. Adiposity is also positively correlated with fat saturation, which is desired to avoid rancidity and oiliness. The fatty acid profile of tissue lipids can be manipulated by diet composition. Feeding strategy affects tissue accretion and protein turnover, thus directly impacting proteolysis. With respect to the impact of pig genotype on dry-cured ham quality, local breeds are generally considered more suitable for producing quality dry hams; however, the majority of dry-cured hams on the market today are from modern pig breeds raised in conventional systems, providing lean hams. The importance of all these factors of pig production is discussed and synthesized, with an emphasis on the main difficulties encountered in dry-cured ham production.
Full Paper
Probiotics in milk replacer influence lamb immune function and meat quality
- A. Santillo, G. Annicchiarico, M. Caroprese, R. Marino, A. Sevi, M. Albenzio
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- Published online by Cambridge University Press:
- 19 September 2011, pp. 339-345
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This study was undertaken to assess the effect of milk replacer (MR) containing Lactobacillus acidophilus and a mix of Bifidobacterium animalis subsp. lactis and Bifidobacterium longum subsp. longum on lamb immune response and on lamb meat quality. A 6-week-trial was conducted on 40 male Comisana lambs, divided into four groups, fed maternal milk (MM), MR, MR with L. acidophilus supplementation (MRL) and MR with a mix (1 : 1) of B. animalis subsp. lactis and B. longum subsp. longum supplementations (MRB). Lambs fed MR containing a mix of bifidobacteria showed the highest in vivo cellular immune response to phytohemagglutinin, whereas MM and MRB showed the highest antibody response to ovalbumin. At day 11 of the trial, MRL displayed the highest value of Interleukin-10; differences disappeared among groups subsequently. Blood cholesterol levels in lambs fed MR containing L. acidophilus was almost halved compared with that found in MM and MR groups. Meat from artificially reared lambs was characterized by trans-11 18:1 and total conjugated 18:2n-6, whereas meat from the dam-suckled lambs was characterized by 14:0, cis-9 14:1 and 16:0. Polyunsaturated to saturated fatty acid ratio was higher in meat of MR, MRL and MRB than in MM lambs. Meat from artificially reared lamb fed MR containing probiotics showed an improved fatty acid profile for human diet.
Mitochondrial respiratory and antioxidative enzyme activities in turkey meat
- S. Janisch, M. Wicke, C. Krischek
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- Published online by Cambridge University Press:
- 22 September 2011, pp. 346-352
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Meat quality and (anti)oxidative metabolism of m. pectoralis superficialis (MPS), m. gastrocnemius (MG) and m. iliotibilialis lateralis (MIL) from turkey toms were analysed. After slaughter, pH of MPS and MG decreased and electrical conductivity of the MPS increased. The MG had generally higher pH values. The meat lightness (L*) and redness (a*) increased in MG and MPS after slaughter. The MPS always had higher L* and lower a* values. Mitochondrial respiratory activities (MRA) were higher in the MIL than the MPS. The activities of superoxide dismutase (SOD) and glutathione peroxidase, analysed in the MPS, increased and the glutathione reductase activity decreased after slaughter. Meat samples with lower pH24 h p.m. had higher drip loss and L* values. The MRA were tendentially lower and the SOD activities higher in these samples. These results indicate a relation between the meat quality, the antioxidative metabolism and mitochondrial respiration.