Contents Of Pigs Research Articles

Heterozygote advantage: the effect of artificial selection in livestock and pets.

There are a number of mutants in livestock and pets that have a heterozygote advantage because of artificial selection for these mutants in heterozygotes and strong detrimental effects from natural selection in homozygotes. In livestock, these mutants include ones that influence milk yield in dairy cattle, fecundity in sheep, litter size in pigs, muscling in beef cattle, color in horses, lean meat content in pigs, and comb morphology in chickens. In pets, these mutants include ones that influence tail length in cats and hairlessness, muscling, color, or ridgeback hair in dogs. A large variety of mutants are responsible, including small or large deletions or insertions and single base-pair nonsynonymous changes. Many of the mutants cause loss of function for the genes involved, a change that results in the pleiotropic effects of a desired phenotype in heterozygotes and low fitness or an undesirable phenotype in mutant homozygotes. I examine how selection changes the frequency of these mutants and provide an approach to estimate the amount of artificial selection that is necessary to maintain these mutants at the high frequencies often observed. The amount of artificial selection ranges from low selection favoring heterozygotes for double muscling in whippet dogs to very strong selection favoring the "flash" (part white, part solid) heterozygote in boxer dogs and the rose comb in chickens. In several examples (rose comb in Wyandotte chickens and the hair ridge in Rhodesian ridgeback dogs), there is actually stronger selection for the mutant than against it, making the frequency of the mutant greater than 50%.

Вміст фосфоліпідів у крові свиней за умов стресу

The article is devoted to the researching of some phospholipids content in pigs’ blood plasma before slaughter. Obtained with the application of ultrasound spleen extract as the biologically active substances has been additionally entered to the pigs feed (I experimental group) at 5 days before slaughter. The results about influence biologically active compounds from the spleen extract at for pre-slaughter stress on separate phospholipids classes content in pigs’ blood plasma were obtained.

Overexpression of Banna mini-pig inbred line fatty acid binding protein 3 promotes adipogenesis in 3T3-L1 preadipocytes.

Fatty acid binding protein 3 (H-FABP, FABP3) has been significantly associated with intramuscular fat (IMF) content in pigs, which is positively correlated with palatability of pork. However, its underlying function is not fully elucidated. We have investigated the effects of overexpression of the FABP3 gene on differentiation and adipogenesis of 3T3-L1 preadipocytes in the fat Banna mini-pig inbred line (fBMIL). Eukaryotic vectors that expressed the FABP3 protein were constructed, and stably established in the 3T3-L1 preadipocytes cell line. Cells were induced in a standard differentiation cocktail. Morphological changes and the degree of adipogenesis were measured by Oil Red O staining assay and triacylglycerol content measurement, respectively. mRNA expression levels of triacylglycerol metabolism-related genes were measured by qPCR. FABP3 significantly promoted differentiation of 3T3-L1 cells and enhanced triacylglycerol levels (P < 0.05). mRNA of the peroxisome proliferator-activated receptor γ (PPARγ), adipocyte fatty acid binding protein (422/aP2) and glycerol-3-phosphate dehydrogenase (GPDH) gene increased markedly (P < 0.05). In conclusion, expression of the FABP3 gene enhances adipogenesis in 3T3-L1 preadipocytes primarily by upregulating lipogenic PPARγ, 422/aP2 and GPDH genes.

Association analysis of interleukin-18 gene with performance traits in Czech Large White pigs

This research focused on recently described MspI and VspI SNPs in interleukin-18 gene and their association with selected performance traits (backfat thickness; lean meat content, average daily gain from birth, average daily gain in test, breeding value for average daily gain, for lean meat content, for reproduction and total breeding value) in a population of 344 Czech Large White sows. Both SNPs were genotyped by PCR-RFLP. In this work, these polymorphisms were associated with backfat thickness and lean meat content. Animals with genotype AA (MspI SNP) had significantly (P &lt; 0.05) lower backfat thickness and higher lean meat content (0.77 ± 0.02 and 62.16 ± 0.23, resp.) compared to GA (0.83 ± 0.02 and 61.40 ± 0.18, resp.). Animals with genotype AA (VspI SNP) had significantly (P &lt; 0.05) lower lean meat content and higher backfat thickness (61.10 ± 0.36 and 0.85 ± 0.03, resp.) compared to GA (62.02 ± 0.16 and 0.77 ± 0.02, resp.). No association between IL-18 polymorphisms and other performance traits was found. Our study revealed that IL-18 could be candidate gene for backfat thickness and lean meat content in pigs.

Thin-Capped Atheromata With Reduced Collagen Content in Pigs Develop in Coronary Arterial Regions Exposed to Persistently Low Endothelial Shear Stress

The mechanisms promoting the focal formation of rupture-prone coronary plaques in vivo remain incompletely understood. This study tested the hypothesis that coronary regions exposed to low endothelial shear stress (ESS) favor subsequent development of collagen-poor, thin-capped plaques. Coronary angiography and 3-vessel intravascular ultrasound were serially performed at 5 consecutive time points in vivo in 5 diabetic, hypercholesterolemic pigs. ESS was calculated along the course of each artery with computational fluid dynamics at all 5 time points. At follow-up, 184 arterial segments with previously identified in vivo ESS underwent histopathologic analysis. Compared with other plaque types, eccentric thin-capped atheromata developed more in segments that experienced lower ESS during their evolution. Compared with lesions with higher preceding ESS, segments persistently exposed to low ESS (<1.2 Pa) exhibited reduced intimal smooth muscle cell content; marked intimal smooth muscle cell phenotypic modulation; attenuated procollagen-I gene expression; increased gene and protein expression of the interstitial collagenases matrix-metalloproteinase-1, -8, -13, and -14; increased collagenolytic activity; reduced collagen content; and marked thinning of the fibrous cap. Eccentric thin-capped atheromata, lesions particularly prone to rupture, form more frequently in coronary regions exposed to low ESS throughout their evolution. By promoting an imbalance of attenuated synthesis and augmented collagen breakdown, low ESS favors the focal evolution of early lesions toward plaques with reduced collagen content and thin fibrous caps-2 critical determinants of coronary plaque vulnerability.

Assessment of pig carcass meatiness in Serbia

The objective of this study was to determine lean meat content in pigs from different farms and smallholdings, which were slaughtered in one abbatoir in Serbia. In Serbia one third of the total number of pigs is slaughtered in slaughterhouses and two thirds in rural households. Results of this examination carried out on 12 523 slaughtered pigs from 9 farms and smallholdings showed that lean meat content in farm pigs ranged from 51.16? 4.31% to 53.27?2.94%. The average quantity of meat in farm pig carcasses was 52.29? 2.04%. The average lean meat percentage of pig carcasses from smallholdings was 48.99?4.85 %. All farm pig carcasses were classified on the basis of meatiness into class U (50.0-54.9% of lean meat content) while pig carcasses from smallholdings were graded as class R (the percentage of meat ranging from 45.0-49.9). Data about lean meat content of pig carcasses in Serbia have not been published during the past twenty years, because lean meat percentage has not been determined. Today, only three abattoirs in Serbia determine lean meat percentage and pay pig producers according to meatiness.

Effect of IGF2 intron3-g.3072G>A on intramuscular fat (IMF) content in pigs raised in Poland

Imprinted IGF2 gene has been intensively studied with regard to its effect on muscularity of pigs. Positive effect of A allele of IGF2 intron3-g.3072G>A on meat percentage in the carcass is well documented, while its effect on meat quality traits and intramuscular fat (IMF) remains elusive. In the present study, performed on 628 Large White, Polish Landrace and Puławska pigs we show that IGF2 intron3-g.3072G>A is associated with the IMF of the meat (p<0.001). We observed highly significant additive effect (a=0.246, p<0.001) for IMF content when all breeds were analyzed together. Animals with G/G genotype had significantly higher IMF than A/A animals and heterozygotes. Our results suggest that IGF2 may influence IMF content in pigs.

Effect of the FABP3 and LEPR gene polymorphisms and expression levels on intramuscular fat (IMF) content and fat cover degree in pigs

Intensive breeding programs, designed to improve lean meat content in pigs, have considerably increased the amount of meat in carcass. It was influenced on poor meat quality and decrease of intramuscular fat (IMF) content. FABP3 and LEPR genes, which are associated with fatty acid metabolism, are regarded as candidate genes for carcass fatness traits in pigs. The objective of this study was to analyze FABP3 and LEPR genes polymorphisms and expression levels and their relationship with fatness parameters and IMF content of the most valuable cuts in carcass (m. longissimus dorsi and m. semimembranosus). The results obtained showed a significantly (P<0.001) higher level of the FABP3 transcript in ham muscle compared to loin, whereas considerably higher (P<0.001) expression of the LEPR gene was observed in loin. The IMF level was affected by FABP3 c.103C>T and c.1811G>C polymorphisms in ham muscle (P<0.05) and by c.103C>T polymorphism in loin (P<0.01). In addition, c.1811G>C polymorphism was associated with individual fatness traits of the loin and carcass (P<0.05). The fat content of whole carcass and primary cuts was positively and highly (P<0.01) correlated with the mRNA abundance of LEPR gene. Furthermore, the expression of FABP3 gene influenced IMF levels in both studied muscles (P<0.01).

Neuronal Genes for Subcutaneous Fat Thickness in Human and Pig Are Identified by Local Genomic Sequencing and Combined SNP Association Study

Obesity represents a major global public health problem that increases the risk for cardiovascular or metabolic disease. The pigs represent an exceptional biomedical model related to energy metabolism and obesity in humans. To pinpoint causal genetic factors for a common form of obesity, we conducted local genomic de novo sequencing, 18.2 Mb, of a porcine QTL region affecting fatness traits, and carried out SNP association studies for backfat thickness and intramuscular fat content in pigs. In order to relate the association studies in pigs to human obesity, we performed a targeted genome wide association study for subcutaneous fat thickness in a cohort population of 8,842 Korean individuals. These combined association studies in human and pig revealed a significant SNP located in a gene family with sequence similarity 73, member A (FAM73A) associated with subscapular skin-fold thickness in humans (rs4121165, GC-corrected p-value = 0.0000175) and with backfat thickness in pigs (ASGA0029495, p-value = 0.000031). Our combined association studies also suggest that eight neuronal genes are responsible for subcutaneous fat thickness: NEGR1, SLC44A5, PDE4B, LPHN2, ELTD1, ST6GALNAC3, ST6GALNAC5, and TTLL7. These results provide strong support for a major involvement of the CNS in the genetic predisposition to a common form of obesity.

Candidate gene expression and intramuscular fat content in pigs

Seventy-two pigs of three genetic groups (Brazilian indigenous breed Piau, Commercial line and Crossbred) of both sexes were slaughtered at four live weights (30, 60, 90 and 120 kg). Intramuscular fat (IMF) content in Longissimus dorsi muscle of each animal was extracted and correlated with candidate gene mRNA expression (ATN1, EEF1A2, FABP3, LDLR, MGP, OBSCN, PDHB, TRDN and RYR1). Within slaughter weight of 120 kg, Piau and Crossbred pigs showed higher IMF content (p < 0.05) than commercial animals, with 2.48, 2.08 and 1.00% respectively. Barrows presented higher values of IMF (p < 0.05) than gilts (1.54 and 1.30% respectively). Gene expression of EEF1A2, FABP3, LDLR, OBSCN, PDHB, TRDN and RYR1 were correlated with IMF (p < 0.05) using the whole dataset. For Piau data only, expression of FABP3, LDLR, MGP, OBSCN, PDHB, TRDN and RYR1 showed correlation with IMF (p < 0.05). Genes that have important roles in lipid transportation inside the cell (FABP3) and tissues (LDLR) showed correlation with IMF of, respectively, 0.68 and 0.63 using the whole data set, and 0.90 and 0.91 using data from Piau animals. The highly positive correlation of the LDLR and FAPB3 expression with IMF content may confirm that these genes are important for fat deposition in the porcine L. dorsi muscle.

Muscle transcriptomic profiles in pigs with divergent phenotypes for fatness traits

BackgroundSelection for increasing intramuscular fat content would definitively improve the palatability and juiciness of pig meat as well as the sensorial and organoleptic properties of cured products. However, evidences obtained in human and model organisms suggest that high levels of intramuscular fat might alter muscle lipid and carbohydrate metabolism. We have analysed this issue by determining the transcriptomic profiles of Duroc pigs with divergent phenotypes for 13 fatness traits. The strong aptitude of Duroc pigs to have high levels of intramuscular fat makes them a valuable model to analyse the mechanisms that regulate muscle lipid metabolism, an issue with evident implications in the elucidation of the genetic basis of human metabolic diseases such as obesity and insulin resistance.ResultsMuscle gene expression profiles of 68 Duroc pigs belonging to two groups (HIGH and LOW) with extreme phenotypes for lipid deposition and composition traits have been analysed. Microarray and quantitative PCR analysis showed that genes related to fatty acid uptake, lipogenesis and triacylglycerol synthesis were upregulated in the muscle tissue of HIGH pigs, which are fatter and have higher amounts of intramuscular fat than their LOW counterparts. Paradoxically, lipolytic genes also showed increased mRNA levels in the HIGH group suggesting the existence of a cycle where triacylglycerols are continuously synthesized and degraded. Several genes related to the insulin-signalling pathway, that is usually impaired in obese humans, were also upregulated. Finally, genes related to antigen-processing and presentation were downregulated in the HIGH group.ConclusionOur data suggest that selection for increasing intramuscular fat content in pigs would lead to a shift but not a disruption of the metabolic homeostasis of muscle cells. Future studies on the post-translational changes affecting protein activity or expression as well as information about protein location within the cell would be needed to to elucidate the effects of lipid deposition on muscle metabolism in pigs.

Genetic diversity of porcine enteric caliciviruses in pigs raised in Rio de Janeiro State, Brazil

Porcine enteric caliciviruses (PEC) belong to the genera Norovirus and Sapovirus within the family Caliciviridae. They are enteric pathogens and are considered potential zoonotic agents. In this study, the circulation of PEC was evaluated by RT-PCR of stool samples and intestinal contents of pigs raised in Rio de Janeiro State, Brazil. Both porcine norovirus (PoNoV) and porcine sapovirus (PoSaV) were detected. The PoNoV strains were classified as genogroup II, genotypes 11, 18 and 19. The PoSaV strains were classified as genogroups III and VII, though some strains could not be classified into any established genogroup, potentially representing a new one. PEC were detected mainly in animals without clinical signs of gastroenteritis.

Muscle lipid metabolism gene expression in pigs with different H-FABP genotypes

Previous studies indicated that polymorphism in heart fatty acid binding protein gene ( H-FABP) was significantly associated with pig intramuscular fat (IMF) content. However, the mechanism of it was not completely clear yet. This study was to investigate the expression level of lipid metabolism genes among H-FABP genotypes using Real-time PCR. Zhaotong Wujin pigs had polymorphism at Hinf I-RFLP and Hae III-RFLP location, and displayed genotypes of HH, Hh, hh and DD, Dd, dd, respectively. The effect of H-FABP genotypes at Hinf I and Hae III site on IMF content were HH > Hh > hh, dd > Dd > DD. Monounsaturated fatty acids (MUFA) exhibited the similar H-FABP genotypes as IMF content. Significantly higher H-FABP mRNA and protein expression levels were found for the Hinf I PCR-RFLP HH and Hae III PCR-RFLP dd genotypes comparing with other genotypes. Expression of genes, including FAS, SCD, SREBP-1c and LPL was significantly higher in Hinf I PCR-RFLP HH and Hae III PCR-RFLP dd genotypes ( P < 0.05) than in other genotypes. This result suggested that H-FABP genotypes affect the IMF content and fatty acid composition in Zhaotong Wujin pigs. Higher IMF content in pigs with Hinf I PCR-RFLP HH and Hae III PCR-RFLP dd genotypes may result from the higher H-FABP mRNA and protein expression, and the higher expression level of lipogenic genes.

Acetyl-CoA carboxylase and stearoyl-CoA desaturase protein expression in subcutaneous adipose tissue is reduced in pigs selected for decreased backfat thickness at constant intramuscular fat content1

The objectives of this study were 1) to determine whether selection toward less subcutaneous fat thickness at constant intramuscular fat content in pigs is related to tissue-specific changes in the expression of lipogenic enzymes acetyl-CoA carboxylase (ACC), stearoyl-CoA desaturase (SCD), and Delta(6)-desaturase (Delta6d); and 2) to investigate tissue specific distribution of the porcine ACC, SCD, and Delta6d. The study was conducted on 20 purebred Duroc barrows. Ten animals were from a group selected for decreased subcutaneous fat thickness at constant intramuscular fat content (experimental group). The other 10 animals were from the unselected (control) group. Distribution of ACC, SCD, and Delta6d was investigated in semimembranosus muscle (SM), subcutaneous adipose tissue (SA), liver (L), kidney (K), heart (H), diaphragm (D), rectus capitis muscle (RCM), and abdominal fat (AF). The enzyme expression was studied in 10 animals in the case of SM and SA and in 4 animals in the case of other tissues. The following expression pattern was established for ACC: SM <or= H = K <or= D < RCM < L < AF = SA, whereas the expression patterns for SCD and Delta6d proteins were SM < H < RCM < D < L < K < AF = SA and RCM = SM = D < L <or= H < SA < K < AF, respectively. Expression of ACC and SCD proteins was less in subcutaneous adipose tissue of the experimental animals when compared with the control group (P < 0.001). However, no difference (P > 0.1) in ACC and SCD protein expression between the control and experimental groups was observed in SM. Expression of Delta6d protein did not differ between the control and experimental groups for SA (P = 0.47) or SM (P = 0.31). There was a positive relationship between muscle SCD protein expression and intramuscular fat content (r = 0.48, P < 0.05). Intramuscular fat content did not correlate with ACC or Delta6d protein expression (P = 0.23 and P = 0.80, respectively). We conclude that SCD might be an effective potential biomarker for intramuscular fat deposition.

An age-dependent association between a leptin C3469T single nucleotide polymorphism and intramuscular fat content in pigs

The objective of this work was to investigate whether the C3469T mutation at exon 3 of the pig leptin ( Lep) gene is associated with fatness and if the magnitude and direction of these associations is consistent within age. Repeated measurements on body weight (BW), ultrasonic subcutaneous backfat (SB) and loin-muscle (LT) thickness, and intramuscular fat (IMF) content and composition were taken at 160, 180, 215 and 225 days of age on 162 Duroc barrows previously genotyped for the C3469T mutation. Plasma leptin concentration was determined at 180 days. A total of 505 records of IMF content and composition, which were determined both in live samples of longisimus dorsi muscle (LM) and in carcass samples of LM and gluteus medius muscle, were used in the analyses. The genotypic frequencies associated with the C3469T Lep mutation were 0.76, 0.23, and 0.01 for TT, TC, and CC genotypes, respectively. The effect of the Lep genotypes was assessed using a Bayesian approach based on a polynomial mixed model on age. No evidence was found for an association of the Lep genotypes neither with BW, SB thickness nor with plasma leptin concentration. The posterior mean of the difference TT–TC ranged, for LT, from 0.82 (160 days, posterior probability density (PP)> 0 of 87%) to 1.98 mm (220 days, PP > 0 of 96%) and, for IMF, from 0.96 (160 days, PP > 0 of 84%) to − 1.64 mg/g DM (220 days, PP > 0 of 2%). The results suggest an age-dependent association of the C3469T Lep polymorphism with LT and IMF, which may be useful to explain some controversial results in the literature concerning the association of this polymorphism with IMF content.

The effect of mutations in the insulin-like growth factor-II and ryanodine receptor-1 genes on biochemical and histochemical muscle fibre characteristics in pigs

Mutations in IGF-II (insulin-like growth factor-II) and RYR1 (ryanodine receptor-1) increase lean meat content in pigs but with different effects on meat quality. Differences in biochemical and histochemical muscle fibre characteristics between the two mutations can thus be suspected. Therefore, the aim of this study was to investigate the effect of the IGF-II mutation (Apat vs. Gpat) on biochemical and histochemical muscle fibre characteristics in relation to the RYR1 genotype (Nn vs. NN). A prenatal effect of the IGF-II mutation could not be excluded but the increased leanness in both mutations was clearly related to postnatal muscle hypertrophy due to an increase in muscle fibre diameter and a higher proliferative capacity in animals carrying the IGF-II mutation. No effect of the IGF-II or RYR1 mutation was found on fibre type composition and metabolic enzyme activities. Interactions between IGF-II and RYR1 genotypes suggest that the mechanism involved in increased leanness due to the impaired RYR1 receptor might influence the underlying mechanisms of the IGF-II mutation.

Sterol regulatory element binding transcription factor 1 expression and genetic polymorphism significantly affect intramuscular fat deposition in the longissimus muscle of Erhualian and Sutai pigs1

Two experiments were performed to elucidate the role of sterol regulatory element binding transcription factor 1 (SREBF1) in i.m. fat (IMF) deposition in pigs. In Exp. 1, LM samples were removed from 4 male and 4 female Erhualian piglets at 3, 20, and 45 d of age, and SREBF1 mRNA expression level and IMF content were measured. Intramuscular fat content and expression of SREBF1 mRNA was greater (P < 0.05) in females than males at all 3 stages of age, providing initial evidence that the level of SREBF1 mRNA expression is related to IMF deposition in muscle of suckling pigs. Additionally, in Exp. 2 there was a positive correlation between the SREBF1 mRNA level and IMF content (r = 0.67, P < 0.01) in 100 Sutai finishing pigs, a synthetic line produced by crossing Erhualian and Duroc pigs. Single-strand conformation polymorphism (SSCP) analysis of the reverse transcription PCR products of the SREBF1 gene revealed 3 genotypes in Sutai pigs with frequencies of 50% for AA, 36% for AB, and 14% for BB, respectively. Both SREBF1 mRNA level and IMF content in muscle were greater (P < 0.05) in AB and BB animals than in AA animals, whereas no difference in backfat thickness was observed among the 3 genotypes. Sequencing analysis identified 2 SNP at T1006C and C1033T within the open reading frame of the SREBF1 gene (NM_214157). Although both are silent mutations, they affected the secondary structure of SREBF1 mRNA. These results suggest that SREBF1 might play an important role in regulation of muscle fat deposition during postnatal growth of pigs. The SNP identified in the SREBF1 gene suggest that it could be used as a genetic marker to improve IMF content in pigs.

Regulation of the muscle‐specific AMP‐activated protein kinase α2β2γ3 complexes by AMP and implications of the mutations in the γ3‐subunit for the AMP dependence of the enzyme

The AMP-activated protein kinase is an evolutionarily conserved heterotrimer that is important for metabolic sensing in all eukaryotes. The muscle-specific isoform of the regulatory gamma-subunit of the kinase, AMP-activated protein kinase gamma3, has a key role in glucose and fat metabolism in skeletal muscle, as suggested by metabolic characterization of humans, pigs and mice harboring substitutions in the AMP-binding Bateman domains of gamma3. We demonstrate that AMP-activated protein kinase alpha2beta2gamma3 trimers are allosterically activated approximately three-fold by AMP with a half-maximal stimulation (A(0.5)) at 1.9 +/- 0.5 or 2.6 +/- 0.3 microm, as measured for complexes expressed in Escherichia coli or mammalian cells, respectively. We show that mutations in the N-terminal Bateman domain of gamma3 (R225Q, H306R and R307G) increased the A(0.5) values for AMP, whereas the fold activation of the enzyme by 200 microm AMP remained unchanged in comparison to the wild-type complex. The mutations in the C-terminal Bateman domain of gamma3 (H453R and R454G), on the other hand, substantially reduced the fold stimulation of the complex by 200 microm AMP, and resulted in AMP dependence curves similar to those of the double mutant, R225Q/R454G. A V224I mutation in gamma3, known to result in a reduced glycogen content in pigs, did not affect the fold activation or the A(0.5) values for AMP. Importantly, we did not detect any increase in phosphorylation of Thr172 of alpha2 by the upstream kinases in the presence of increasing concentrations of AMP. Taken together, the data show that different mutations in gamma3 exert different effects on the allosteric regulation of the alpha2beta2gamma3 complex by AMP, whereas we find no evidence for their role in regulating the level of phosphorylation of alpha2 by upstream kinases.

Heart fatty acid binding protein is upregulated during porcine adipocyte development1

Heart fatty acid binding protein (H-FABP) has been associated with intramuscular fat content in pigs. In the current study, we showed that expression of H-FABP mRNA in adipose tissue of adult pigs was 8.5% of that in heart and 30% of that in skeletal muscle, and that H-FABP mRNA level was more than 10% of that of adipocyte fatty acid binding protein mRNA in adipose tissue. Levels of H-FABP mRNA reached a maximum in adipose tissue from 7-d neonates, with no further increase in the adult. Also, H-FABP mRNA was induced during adipogenic differentiation of stromal-vascular cells derived from adipose tissue and skeletal muscle. In conclusion, H-FABP may play a role in adipose tissue development and function in the pig.

The digestible energy and net energy content of two varieties of processed rice in pigs of different body weight

An experiment was conducted to examine the effects of two varieties of extruded rice (medium-grain variety Amaroo and long-grain variety Doongara) on the digestible energy (DE) and net energy (NE) content in pigs of two body weight groups (8 and 55 kg). Diets contained 857 g rice/kg, 50 g meat and bone meal/kg, 82 g fish meal/kg and other trace ingredients. Diets were fed at 0.05 proportion of body weight for 8 kg pigs (≈400 g/day) and at 0.0375 of body weight for 58 kg pigs (≈2175 g/day). Digestibility of gross energy (GE) was determined using titanium dioxide as an indigestible marker, and the DE content of rice was calculated by subtracting the DE content of ingredients other than rice. The mean (±S.E.M.) coefficient of total tract apparent digestibility (CTTAD) of GE and DE content (MJ/kg air-dry basis) of rice were 0.92 (0.003) and 15.1 (0.06), respectively. The rice variety did not influence the DE content. However, the body weight of the pig significantly influenced the DE content of rice such that weaner pigs extracted less energy from a given rice than grower pigs (up to 0.5 MJ/kg, P<0.001). In the second experiment, the CTTAD of GE and DE content (MJ/kg DM) of cooked medium-grain rice Amaroo (autoclaved for 20 min at 120 °C; rice:water ratio of 1:2, w/w) was examined in 10 kg pigs. The mean CTTAD of GE and DE values (±S.E.M.) were 0.918 (0.001) and 15.10 (0.031), respectively. The estimated mean NE content of rice using CVB and INRA formulae was 11.5 MJ/kg (air-dry basis).