CC Pigs Research Articles

Novel saliva biomarkers for stress and infection in pigs: Changes in oxytocin and procalcitonin in pigs with tail-biting lesions

There is a need for feasible and reliable measures to improve and evaluate production animal health and welfare. Oxytocin is a promising novel stress-related biomarker and procalcitonin may be a measure of sepsis. Both have potential for use in pigs and can be measured from saliva, which allows on-farm sampling with minimal impact on the animals. The current study sought to further validate these measures using a spontaneous situation that causes both stress and an increased risk for infections in pigs, namely a tail-biting outbreak. Grower pigs on a commercial farm belonging to three different phenotype groups were selected: control pigs from control pens (CC, N = 30), control pigs (CTB, N = 10), and pigs with tail lesions from pens with a tail-biting outbreak (LTB, N = 27). A single sample of saliva was collected from each pig and analysed for a range of biomarkers related to stress, infection, inflammation, and immune activation. Oxytocin tended to be higher in CC pigs than in LTB pigs, while cortisol was higher in CTB than CC pigs. Procalcitonin tended to be higher, and haptoglobin was higher in LTB than in CC pigs. Adenosine-deaminase levels were similar between phenotypes. These results provide further evidence for the link between stress and tail biting, and indicate that tail-biting lesions are potential routes for systemic spread of bacteria. Further research into saliva oxytocin as a stress biomarker and saliva procalcitonin as a sepsis biomarker in pigs is warranted.

Age Evolution of Lipid Accretion Rate in Boars Selected for Lean Meat and Duroc Barrows.

Simple SummaryFat deposition profile and fatty acid biosynthesis in adipose tissues are two relevant metabolic processes for breeding companies as the fat content of meat relates to its technological, organoleptic, and nutritional quality. Age, breed, and sex have a great impact on fat metabolism. Therefore, in the present experiment, a labeled saturated fatty acid was added to the diet of pigs belonging to three different producing types during two growth phases, to define the rate of its incorporation into body fat. In addition, the activity of the enzyme stearoyl-CoA desaturase, which promotes the conversion of some saturated fatty acids into monounsaturated, was analyzed. In the growing phase, direct incorporation of fat from diet was higher than biosynthesis in most adipose tissues, whereas in the fattening phase it was higher only in the liver, revealing the changing roles of organs in fat metabolism with age. The leaner pigs also obtained a higher fat incorporation, denoting higher reliance on dietary fatty acids for fat deposition; overall, real stearoyl-CoA desaturase activity was higher in the fattening phase.Fatty acid (FA) deposition in growing–fattening pigs is mainly based on endogenous lipid synthesis, but also direct FA incorporation from the diet. To evaluate the direct fat incorporation rates and the endogenous desaturation action of the stearoyl-CoA desaturase (SCD) enzyme, a deuterium (D)-labeled saturated FA (d35-C18:0) was added to the diet. Sixteen three-way (3W) crossbred boars, and thirty-two purebred Duroc barrows homozygous for the SCD single nucleotide polymorphism rs80912566 (16 CC/16 TT), were used. Half of the animals of each genotype belonged to the growing and fattening phases. The fractional incorporation rate (FIR) of dietary fat in growing pigs was generally higher in adipose tissues, whereas in fattening pigs it was higher in the liver. Duroc pigs exhibited lower FIRs than 3W pigs, suggesting lower rates of endogenous synthesis by 3W pigs. Real fractional unsaturation rates (FURs) increased with age by the higher FIRs in 3W pigs and the de novo synthesis pathway in Duroc genotypes. Moreover, pigs carrying the SCD_T allele showed more enhanced oleic acid biosynthesis than Duroc CC pigs. In conclusion, suitable feeding protocols should be designed for each pig type to optimize production traits, considering that the metabolic pathway of FA for its deposition may differ.

Transcriptome shifts triggered by vitamin A and SCD genotype interaction in Duroc pigs

BackgroundThe composition of intramuscular fat depends on genetic and environmental factors, including the diet. In pigs, we identified a haplotype of three SNP mutations in the stearoyl-coA desaturase (SCD) gene promoter associated with higher content of monounsaturated fatty acids in intramuscular fat. The second of these three SNPs (rs80912566, C > T) affected a putative retinol response element in the SCD promoter. The effect of dietary vitamin A restriction over intramuscular fat content is controversial as it depends on the pig genetic line and the duration of the restriction. This study aims to investigate changes in the muscle transcriptome in SCD rs80912566 TT and CC pigs fed with and without a vitamin A supplement during the fattening period.ResultsVitamin A did not affect carcass traits or intramuscular fat content and fatty acid composition, but we observed an interaction between vitamin A and SCD genotype on the desaturation of fatty acids in muscle. As reported before, the SCD-TT pigs had more monounsaturated fat than the SCD-CC animals. The diet lacking the vitamin A supplement enlarged fatty acid compositional differences between SCD genotypes, partly because vitamin A had a bigger effect on fatty acid desaturation in SCD-CC pigs (positive) than in SCD-TT and SCD-TC animals (negative). The interaction between diet and genotype was also evident at the transcriptome level; the highest number of differentially expressed genes were detected between SCD-TT pigs fed with the two diets. The genes modulated by the diet with the vitamin A supplement belonged to metabolic and signalling pathways related to immunity and inflammation, transport through membrane-bounded vesicles, fat metabolism and transport, reflecting the impact of retinol on a wide range of metabolic processes.ConclusionsRestricting dietary vitamin A during the fattening period did not improve intramuscular fat content despite relevant changes in muscle gene expression, both in coding and non-coding genes. Vitamin A activated general pathways of retinol response in a SCD genotype-dependant manner, which affected the monounsaturated fatty acid content, particularly in SCD-CC pigs.

Antagonistic maternal and direct effects of the leptin receptor gene on body weight in pigs.

Maternal effects on offspring growth can impact survival and evolution of natural and domesticated populations. Genetic correlation estimates often support a negative relationship between direct and maternal effects. However, the genetic underpinnings whereby this antagonism operates are unclear. In pigs, sow feeding status and body composition condition piglet development and growth. We hypothesized that variants in genes impacting these traits may be causative of maternal influences that could be antagonistic to the direct effects for piglet growth. A recessive missense mutation (C>T) in the porcine leptin receptor (LEPR) gene (rs709596309) has been identified as the possible causal polymorphism for increased feed intake and fatness. Using data from a Duroc line, we show that the TT sows exerted a negative impact on the body weight of their offspring at the end of the growing period of similar extent to the positive direct effect of the TT genotype over each individual. Thus, TT pigs from TT dams were about as heavy as CC and CT (C–) pigs from C–dams, but TT pigs from C–dams were around 5% heavier than C–pigs from TT dams. In contrast, body composition was only influenced by LEPR direct effects. This antagonism is due to a higher propensity of TT pigs for self-maintenance rather than for offspring investment. We show that TT pigs consumed more feed, favored fatty acid uptake over release, and produced lighter piglets at weaning than their C–counterparts. We conclude that LEPR underlies a transgenerational mechanism for energy distribution that allocates resources to the sow or the offspring according to whether selective pressure is exerted before or after weaning.

Identification of porcine CTLA4 gene polymorphism and their association with piglet diarrhea and performance traits.

The objective of this study was to evaluate the association between the cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) gene and piglet diarrhea. In this study, the mRNA expression of the CTLA4 gene increased significantly in IPEC-J2 cells after Escherichia coli K88 infection. Single nucleotide polymorphisms (SNPs) located in the 5' flanking region (SNPs g.107281989C>T) and 3'-untranslated region (3'-UTR; SNPs g.107288753C>A) were identified, and they were in linkage disequilibrium in both Min pigs and the Landrace population. Association analysis showed that Landrace piglets with a TT or AA genotype had a lower diarrhea index, and AA animals had higher average daily gain when compared to CC pigs, respectively (p < 0.05). However, the relationship between SNPs and diarrhea and performance traits in the Min population was not significant. Haplotype analysis indicated that the TC haplotype had the lowest diarrhea index. The 5' flanking deletion assay suggested that SNP g.107281989C>T was a molecular marker instead of the functional marker. This research demonstrated that genetic variances in the CTLA4 gene had significant effects on Landrace piglet diarrhea resistance.

In vivo effect of a TLR5 SNP (C1205T) on Salmonella enterica serovar Typhimurium infection in weaned, specific pathogen-free Landrace piglets.

Toll-like receptor 5 is a pattern-recognition receptor for bacterial flagellin. We previously reported that a single nucleotide polymorphism (SNP) of swine TLR5, C1205T, impairs recognition of Salmonella typhimurium (ST) flagellin and ethanol-killed Salmonella Choleraesuis (SC). In the present study, weaned, specific pathogen-free (SPF) Landrace piglets with CC, CT or TT genotypes were orally infected with ST (L-3569 strain) to determine the effect of this specific SNP on ST infection in vivo. Eighteen ST-infected piglets (six each with CC, CT, or TT) exhibited fever and diarrhea for 1 week after infection. TT piglets had the longest duration of fever. TT piglets had the greatest mean diarrhea score during the experimental period, followed by CT and CC piglets. Fecal ST shedding was greater in CT and TT pigs than CC pigs from 2 days after infection. Serum haptoglobin concentration increased in ST-infected piglets and to greater extents in CT and TT pigs than CC pigs. Daily weight gain was lower in infected pigs, particularly TT piglets, than control pigs. To the best of our knowledge, this study is the first to demonstrate that impairment of TLR recognition affects pig susceptibility to disease in vivo. Thus, piglets with the T allele of swine TLR5 (C1205T) exhibit impaired resistance to ST infection. Furthermore, elimination of the T allele of this SNP from Landrace pigs would lead to enhancement of their resistance to ST infection.

Investigation of the Perilipin 5 gene expression and association study of its sequence polymorphism with meat and carcass quality traits in different pig breeds

The growing request for healthier fatty acid composition of animal products is raising the necessity of a deeper knowledge of the main factors controlling fatty acids storage in muscle and backfat. Perilipin (PLIN) 5, and the whole Perilipin family, seem to play a crucial role in the regulation of lipids deposition as code for proteins coating intracellular lipid droplets surface. Nevertheless, the knowledge of these genes in pig is still incomplete. The present research was aimed at investigating in different pig breeds the PLIN5 gene, analysing its expression level and the associations of the variability in its downstream gene region with pork meat and carcass quality traits. Moreover, the PLIN5 protein localisation in porcine skeletal muscle was investigated through immunofluorescence, resulting to be widespread in Semimembranosus muscle (SM) myofibers. The identified single nucleotide polymorphism (SNP) rs327694326 (NC_010444.4:g.74314701T>C) located in PLIN5 downstream region was analysed in different pig populations, represented by 512 Italian Large White (ILW) pigs, 300 Italian Duroc (IDU) samples, 100 Italian Landrace, 100 Pietrain and 60 pigs belonging to three Italian native breeds (20 samples of Cinta Senese, 20 Calabrese and 20 Casertana pigs). The C allele was found in ILW, IDU and Pietrain pigs. In ILW pigs this SNP showed results indicating a possible association with oleic and cis-vaccenic fatty acid contents in backfat tissue. Furthermore, as PLINs are known to regulate lipases activity, we tested if the rs327694326 SNP was associated with differences in Hormone-sensitive lipase (LIPE) gene expression levels. In SM of ILW pigs, PLIN5 C allele was associated with significantly lower LIPE transcription levels than T allele (P=0.02 for Student’s t test of TT v. CT samples, P<0.0001 for TT v. CC pigs), whereas in IDU breed no significant difference was noticed in LIPE transcription levels between TT and TC animals. The results may suggest that variations in the PLIN5 sequence may be linked to LIPE expression through a still poorly known regulative molecular process.

Case Study: Differences in social behaviors and mortality among piglets housed in alternative lactational systems

Farrowing crate alternatives allow greater sow locomotion and behavioral expression but may affect piglet welfare. This study compared productivity and piglet behavior in 3 lactational housing systems: a pen (PN, n = 30); a closed crate (CC, n = 19); and a hinged crate (OC, n = 19). Until piglets reached 2 wk of age, CC and OC were identical with sows fixed in a crate within a pen (CRT). After 2 wk, OC sows were released. At 27 d of age, 2 female and 2 male pigs per litter were observed separately in an exploratory behavior test and a different, but equivalent, set of 4 pigs were observed with an unfamiliar pig in a social test. In the social test, PN (P < 0.001) and CC (P = 0.02) pigs spent longer in nonaggressive touch than OC pigs. Housing also affected pig productivity. Prior to d 15, pig weight was 9% and daily gain was 7% greater in CRT than PN (both, P < 0.001). Concurrently, PN mortality (27%) was greater than CRT (13%; P = 0.006). However, from d 16 to weaning, pig weight (P = 0.55), gain (P = 0.75), and mortality (P = 0.98) did not differ between systems. Overall, housing had little effect on piglet behavior but affected productivity and welfare. Pigs from the PN treatment had decreased early growth and increased mortality, but pigs from OC and CC crates did not differ. In sum, although limited to the study farm, the findings of this investigation suggest that the OC crate appears to provide the best balance of the sow and piglet needs.

Association of missense MTTP gene polymorphism with carcass characteristics and meat quality traits in pigs

Microsomal triglyceride transfer protein, coded by MTTP gene, has multiple functions including participation in formation of chylomicrons, low-density lipoproteins, and very low-density lipoproteins. Therefore MTTP protein plays a key role in the transport of fats and cholesterol between membrane vesicles, which can be associated with lipid metabolism. In the present study, ENSSSCT00000010052.2:c.2518C&amp;gt;T (rs335896411) missense polymorphism (Leu&amp;gt;Phe) located in exon 18 of MTTP gene was investigated in order to estimate its potential association with production traits of pigs. The analysis was performed with five breeds (Duroc, Landrace, Large White, Pietrain, Pulawska pigs) and totally 678 pigs, for which the genotypes of c.2518C&amp;gt;T polymorphism were identified by the polymerase chain reaction–restriction fragment length polymorphism method. The present study showed a significant association of c.2518C&amp;gt;T polymorphism with carcass yield. When analyzing the whole population, CC homozygotes showed significantly higher carcass yield than heterozygotes (P ≤ 0.05). Moreover, c.2518C&amp;gt;T single nucleotide polymorphism (SNP) affected pH measured in loin (m. longissimus dorsi) and ham (m. semimembranosus) 45 min after slaughter. For both parameters, the highest pH values were obtained for CC pigs, while the lowest for heterozygotes (P ≤ 0.05). The SNP analyzed was also related with meat colour (yellowness intensity (b*)). Previous research confirmed that ENSSSCP00000009789.2:p.Leu840Phe polymorphism, via affecting MTTP protein activity, influences metabolism of fatty acids. Additionally, results obtained in the present study suggest that the analyzed missense mutation in porcine MTTP gene can be one of the potential genetic factors associated with meat quality (pork pH and colour) and carcass yield.

Short-term effect of supplemental yeast extract without or with feed enzymes on growth performance, immune status and gut structure of weaned pigs challenged with Escherichia coli lipopolysaccharide.

BackgroundThis study investigated the response of piglets receiving a yeast extract without or with a multi-enzyme mixture compared with an antimicrobial growth promoter (AGP) on performance, immune status and gut structure after an E. coli lipopolysaccharide (LPS) challenge. Thirty-six pigs were allotted to six treatments including: a non-challenged control (NCC); LPS-challenged control (CC); CC + AGP; CC + yeast extract; CC + enzymes; and CC + enzymes + yeast extract. On d 7, pigs were bled and thereafter injected with LPS or sterile saline. Blood samples were collected at 6, 48, and 96 h post-challenge. After 96 h post-challenge, pigs were euthanized to obtain duodenal, jejunal and ileal samples.ResultsOverall (d 1 to 11), compared with CC pigs, AGP attenuated the LPS-induced reduction in ADG (P = 0.004), ADFI (P = 0.03) and gain/feed ratio (P = 0.01). At 6 h post-challenge, AGP pigs had lower plasma urea N (PUN; P = 0.02) and serum TNF- α concentration (P = 0.07), and higher platelet count (P = 0.04) and serum IL-10 concentration (P = 0.02) than CC pigs. At 48 h post-challenge, AGP pigs had lower PUN (P = 0.02) than CC pigs, whereas enzymes + yeast extract interacted non-additively (P = 0.001) to reduce PUN. At 96 h post-challenge, AGP pigs had lower PUN (P = 0.02) and higher duodenal (P = 0.03), jejunal (P = 0.01) and ileal (P = 0.07) villus height than CC pigs. In addition, enzymes + yeast extract interacted additively and non-additively to reduce ileal IFN-γ (P < 0.0001) and IL-10 (P = 0.012) expression, respectively. Generally, no differences (P > 0.10) were observed between AGP and enzymes + yeast extract pigs on other measured parameters except for the downregulation of ileal IFN-γ (P < 0.0001) and TNF-α (P = 0.003) in enzymes + yeast extract pigs at 96 h post-challenge.ConclusionsThe LPS challenged piglets receiving enzymes + yeast extract showed beneficial responses in gut structure and immunity commensurate with those receiving antibiotics, though the latter had better overall growth performance.

Analysis on the Relationship between an Intronic Polymorphism in &lt;em&gt;Troponin C&lt;/em&gt; Gene (TNNC1) with Pork Quality Traits

The objective of this study was to investigate the distribution of genotype and analyze the effect of the intronic polymorphism (g.C716G) of TNNC1 gene on meat quality traits of Mong Cai (MC) pig. In total, 118 animals were used for phenotype record and genotyping by PCR-RFLP method. Results showed that the presence of allele G was more than twice as frequent as allele C at the polymorphic site (0.70vs. 0.30) and the frequency of CC genotype was very low (0.07) compared to CG (0.47) and GG (0.46) genotypes. The pH value at 45 min post- mortem was different (p<0.01) among three genotype groups with the lowest found in pigs bearing CC genotype (6.43). Significantly higher compression force value (6.16 kg) found in CC pigs implied that loins from these animals were less tender than those from CG animals. Other parameters of meat quality including drip loss and meat color were not affected by this polymorphism. Moreover, in the analysis of thirty MC pigs, although the relationship between genotypes and muscle fiber type composition was unclear, there was a trend of increasing IIa fiber and decreasing IIb fiber percentage in pigs with GG genotype (p = 0.059 and p = 0.082, respectively). In conclusion, the SNP examined in TNNC1 gene may be of interest in selection for meat tenderness in MC pigs; however as this is not a causative polymorphism, further studies on the association of TNNC1 with meat quality traits regarding to the interaction with other functional genes in surrounding regions are recommended.

Metabolic adaptation of two pig muscles to cold rearing conditions1

Cold environment represents an external stress modulating animal growth and energy use. At muscle level, adaptation to cold conditions potentially involves energy homeostasis regulation gauged by the adenosine monophosphate (AMP)-activated protein kinase (AMPK). Our study aimed at evaluating the bare effects of short- and long-term cold exposure on growth performance, carcass traits, and metabolic characteristics of the oxidative semispinalis (SS) muscle and glycolytic LM and to evaluate the reversibility of short-term effects, with a special emphasis on AMPK activity. A total of 84 pigs fed ad libitum and individually housed were submitted after weaning to either Cold (from 23 ± 1 to 15 ± 3°C) or thermoneutral (T; from 28 ± 1 to 23 ± 1°C) temperature up to 24.7 ± 1.6 kg BW (25 BW). Twelve Cold and 12 T piglets were then slaughtered the same day. Eighteen remaining Cold piglets were reared at 12 ± 2°C (CC) whereas 18 Cold and 24 T piglets were reared at 23 ± 4°C (CT and TT, respectively) and slaughtered at 114.3 ± 5.9 kg (115 BW). The LM and SS samples were analyzed to determine glycolytic potential (GP), activities of lactate dehydrogenase (LDH), citrate synthase (CS), and β-hydroxy-acyl-CoA dehydrogenase (HAD) and to quantify AMPK phosphorylation Threonine 172 phosphorylated form of AMPK α1+α2 isoforms (pAMPK) / total AMPK α1+α2 isoforms (AMPK). Despite a greater ADFI (P < 0.001), Cold piglets exhibited less ADG (P < 0.001) and body fatness (P < 0.03) attesting an acute adaptation to a short-term cold exposure. A long-term cold adaptation evaluated on 115 BW pigs increased ADFI (P < 0.001) but did not influence ADG and carcass lean meat content. Cold environment influenced the dynamic of muscle metabolism in a muscle type dependent manner corresponding to an earlier and acute adaptation in SS from 8 kg onward and a belated adaptation in LM from 25 BW to 115 BW. Cold exposure was associated with a progressive increase of muscle oxidative capacity, first in the SS with greater HAD (P = 0.002) and CS activities (P = 0.03) at 25 BW and then both in SS and LM at 115 BW (P < 0.001). Conversely, in LM of CC pigs, increased GP (P < 0.001) and LDH activity (P = 0.03) were observed in addition to increased CS and HAD activities, highlighting the ability of LM to increase both its glycolytic and oxidative metabolism and to diversify its energy substrates. Pigs from CC group exhibited also less pAMPK/AMPK (P < 0.01) specifically in red SS muscle, denoting a reduced metabolic stress of this muscle after a long-term cold adaptation.

Characterization of Porcine Matrix Metalloproteinase 23 (pMMP-23) Gene and Its Association with Litter Size Traits

The matrix metalloproteinase 23 (MMP-23), which might play a role in ovulation in mammals, was one of the promising candidate genes for litter size traits in pigs. In the present research, partial sequence of porcine MMP-23 (pMMP-23) gene, including exons 2–8 (GenBank: EU360790), was obtained. Real-time PCR analysis revealed that pMMP-23 gene was highly expressed in ovary. PCR-Sau3A I-RFLP and PCR-Acc II-RFLP assay were established to detect a C/T mutation in exon 3 (EU360790: g. 269C>T) and an A/G mutation in exon 4 (EU360790: g. 505A>G), respectively. Association study for these two SNPs with litter size was assessed in three independent populations (Minzhu, Landrace I and Landrace II). Statistical analysis demonstrated that for second and subsequent litters, TT sows produced more TNB than CC pigs in Landrace breed (P<0.05) at g. 269C>T locus, and the additive effect was significant (P<0.05); GG sows produced more TNB and NBA than AA pigs in Minzhu (P<0.01) and Landrace breeds (P<0.05) at g. 505A>G locus, and the additive effect was significant (P<0.01 or P<0.05). Our study suggested that the pMMP-23 gene might be a novel candidate gene for litter size traits, and g. 505A>G locus might be a useful molecular marker for marker assisted selection (MAS).

The effects of leptin receptor (LEPR) and melanocortin-4 receptor (MC4R) polymorphisms on fat content, fat distribution and fat composition in a Duroc × Landrace/Large White cross

The effects of mutations LEPR c.1987C>T and MC4R c.1426G>A on leptin receptor and melanocortin receptor genes, which are involved in regulating appetite, have been studied in a Duroc×Landrace/Large White cross. To the best of our knowledge, this is the first report of the presence of LEPR c.1987C>T effects outside the Iberian breed or crosses of Iberian with other breeds. Both mutations modify several traits related to adipose tissue content. LEPR TT pigs have a lower percentage of joints rich in muscle tissue and a higher percentage of joints rich in adipose tissue in the carcass (5.8% lighter loins, 6.0% heavier lard) than LEPR CC pigs. LEPR TT pigs also have a greater adipose tissue content in their hams (8.0%) and shoulders (24%) than LEPR CC homozygous pigs. They also have larger backfat thickness values (between 1.5 and 7.5mm depending on anatomical location). LEPR TT pigs show a clear increase in saturated fatty acid content at the expense of monounsaturated and polyunsaturated content when compared to LEPR CC pigs. MC4R GG pigs have a higher percentage of joints rich in muscle tissue and a lower percentage of joins rich in adipose tissue in the carcass (6.3% heavier loins and 4.7% lighter lard), lower fat cover and higher muscle fraction in hams (9.3% and 3.4%, respectively), and a larger fat content in B. femoris (12.2%) and in whole ham muscle mass (8.6%) than MC4R AA pigs. Whereas most effects of both mutations can be explained by an increase in feed intake, the strong effects of LEPR c.1987C>T on saturated fatty acid content in several anatomical locations are probably due to the local effect of a compromised leptin signaling system. The consequences of selecting these mutations for cured meat production are discussed.

Diversidad genética en cerdos criollos mexicanos con genes candidatos asociados a características productivas

El objetivo de este trabajo fue comparar la variabilidad, diversidad y distancias genéticas entre cerdos criollos, Pelón Mexicano (CPM) y Cuinos (CC), con Yorkshire, cuanto a los genes candidatos CAST, DECR1, HAL, HFABP4, LEP, LIPE, MCR4, MYOG, RN y CHX, a través de analysis por PCR-RFLP. Se evaluaron 180 cerdos: 59 CPM, 65 CC y 56 Yorkshire. Se analizaron las frecuencias génicas y genotípicas, heterocigosidad, distancias genéticas y árboles filogenéticos entre grupos raciales. Para CAST, DECR1, HFABP4, LEP, MCR4 y CHX las frecuencias génicas y genotípicas fueron diferentes al comparar las tres razas. En LIPE, los CC fueron iguales a los Yorkshire; en cuanto a MYOG, los CPM fueron iguales a los Yorkshire. No hubo diferencias entre poblaciones criollas y Yorkshire en las frecuencias génicas y genotípicas para HAL y RN. Los cerdos Yorkshire presentaron mayor frecuencia en alelos favorables para CAST, LIPE, MCR4 y MYOG, menor frecuencia de DECR1, HFABP4, CHX, y moderada en LEP. La heterocigosidad promedio para todos los genes fue mayor en CPM (0,42±0,05) y similar en CC (0,33±0,06) y Yorkshire (0,35±0,05). Al calcular distancias genéticas con todos los genes, los CC se encuentran más distantes de los Yorkshire.

Diet‐Dependent Effects of Minimal Enteral Nutrition on Intestinal Function and Necrotizing Enterocolitis in Preterm Pigs

A rapid advance in enteral feeding is associated with necrotizing enterocolitis (NEC) in preterm infants. Therefore, minimal enteral nutrition (MEN) combined with parenteral nutrition (PN) is common clinical practice, but the effects on NEC and intestinal function remain poorly characterized. It was hypothesized that a commonly used MEN feeding volume (16-24 mL/kg/d) prevents NEC and improves intestinal structure, function, and microbiology in preterm pigs. After preterm birth pigs were stratified into 4 nutrition intervention groups that received the following treatments: (1) PN followed by full enteral formula feeding (OF group, n = 12); (2) PN supplemented with formula MEN and followed by full formula feeding (FF, n = 12); (3) PN plus colostrum MEN followed by formula feeding (CF, n = 12); (4) PN plus colostrum MEN followed by colostrum feeding (CC, n = 10). NEC was absent in the CC group but frequent in the other groups (50%-67%). Compared with other groups, CC pigs showed improved mucosal structures, brush border enzyme activities, and hexose absorption (all P < .05). Relative to formula MEN, colostrum MEN thus improved gut function but did not prevent later formula-induced gut dysfunction and NEC. However, in CF pigs, intestinal lesions were restricted to the colon, compared with all regions in OF and FF pigs, which indicated proximal protection of colostrum MEN. Bacterial composition was not affected by MEN, diet, or NEC outcomes, but bacterial load and concentrations of short-chain fatty acids were reduced in the MEN groups. Colostrum MEN improves intestinal structure, function, and NEC resistance in preterm pigs but does not protect against gut dysfunction and NEC associated with later full enteral formula feeding.

A C/T mutation in microRNA target sites in BMP5 gene is potentially associated with fatness in pigs

Bone morphogenetic protein 5 ( BMP5) gene was suggested to be a potential positional candidate gene for fatness trait QTLs on SSC7. Here by comparative sequencing of BMP5 gene in Meishan (MS) and Large White (LW) pigs, one SNP *131C > T in 3′ un-translated region was detected. Association analysis results in 322 LW × MS F 2 pigs showed that CC pigs had thinner back fatness and heavier ham than TC ( P < 0.05 or P < 0.1), and had a higher fat percentage and a lower lean meat percentage ( P < 0.1) than TT. Moreover, this C/T transition was predicted to alter BMP5 interaction with let-7c and miR- 184 by using RNA22 and RNAhybrid. The negative expression of BMP5 gene with let-7c and miR-184 detected from miRNAs overexpression in swine fibroblast, indicating these 2 miRNAs might participate in the translational inhibition of BMP5 gene. Overall, SNP *131C > T might be a good marker for fatness traits.

Sequence Characterization, Tissue-specific Expression and Polymorphism of the Porcine( Sus scrofa) Liver-type Fatty Acid Binding Protein Gene

In this study, the full-length cDNA of porcine liver-type fatty acid binding protein gene ( L-FABP) was obtained by the rapid amplification of cDNA ends (RACE). The nucleotide sequence and the predicted protein sequence share a high sequence identity with their mammalian counterparts. Semi-quantitative RT-PCR revealed that porcine L-FABP gene is expressed in all twelve tissues studied, but a transcript is more abundant in liver and small intestine than in other tissues. The part genomic DNA of the porcine L-FABP gene was amplified by PCR. The coding region of the pig L-FABP gene is organized in four exons and spans an approximate 2.62 kb genomic region. Comparative sequencing of four pig breeds revealed a C→T single nucleotide polymorphism (SNP) within exon 2. The allele and genotype frequencies differed significantly between indigenous Chinese Zang, Dahe, and Yanan pigs with higher frequencies of allele C and genotype CC and Yorkshire pigs with higher frequencies of allele T and genotype TT ( P < 0.01). The association analysis suggested that the C<T polymorphism was associated with intramuscular fat content, indicating that the SNP is a potential molecular marker for intramuscular fat content.

Endogenous Gut Nitrogen Losses in Growing Pigs Are Not Caused by Increased Protein Synthesis Rates in the Small Intestine

The purpose of this study was to establish, using a flooding dose of L-[ring 2, 6-(3)H] phenylalanine, whether feeding pigs diets that induce high endogenous gut nitrogen losses (ENL) also increases protein synthesis rates in (PSR) the visceral organs. Twelve 18-kg Yorkshire barrows with catheters in the right and left jugular veins were fed for 3 wk either casein-cornstarch- (CC) or barley-canola meal- (BCM) based diets formulated to a similar digestible energy /crude protein ratio and designed to induce either low or high ENL, respectively. Pigs were infused with 10 mL/kg body weight of a 150 mmol. L(-1) phenylalanine solution containing 230 MBq. L(-1) labeled phenylalanine for 12 min and killed 20 min later. Plasma phenylalanine specific radioactivity (SRA) rose to a plateau value within 3 min of starting the infusion and did not change (P > 0.10) thereafter. Fractional rates of protein synthesis (K(s), %/d) based on SRA in plasma- or intracellular-free phenylalanine did not differ (P > 0.10) in all tissues except pancreas (P < 0.05). Diet affected K(s )in liver (P < 0.01) and colon (P < 0.05) but not in pancreas, duodenum, jejunum and cecum. Based on plasma-free phenylalanine SRA, liver K(s)were 85.4 +/- 11.0 vs. 60.5 +/- 5.2 (mean +/- SEM) in CC- and BCM-fed pigs, respectively; these values were 82.3 +/- 4.7 vs. 98.2 +/- 5.8 in the colon. The absolute amount of protein synthesis (g.d(-1)) was higher in the liver (P < 0.05) and pancreas (P < 0. 05) of the CC pigs compared to BCM pigs. No dietary effects were observed in all other organs (P > 0.10). The present results suggest that feeding growing pigs a BCM diet that induces high ENL does not affect PSR in the small intestine of growing pigs from which >50% of ENL originates.