Effects of Genotype on Pig Carcass, Meat Quality and Consumer Sensory Evaluation of Loins and Bellies.

The objective of the study was to compare carcass and meat quality among Lithuanian White, Lithuanian Indigenous Wattle and conventional hybrids as well as consumer sensory evaluations. The pigs were slaughtered at a live weight of approximately 95-100 kg. After 24 h of slaughter, carcasses were evaluated and sampled for the analysis of meat quality traits of loins and consumer evaluation of cooked loins and baked bellies. The pigs of both Lithuanian breeds had higher backfat thickness and depth of underbelly but lower loin area compared with hybrids. However, more fatty local breeds had higher intramuscular fat content but lower cholesterol content than hybrids. The loins from local pigs displayed higher pH and colour with lower lightness and yellowness but higher redness and also lower cooking loss, shear force and hardness than conventional hybrids. Pork from lean hybrids had a higher proportion of polyunsaturated fatty acids and more favourable lipid quality indices such as atherogenic (AI) and thrombogenic (TI) indices and the hypocholesterolemic/hypercholesterolemic (h/H) ratio; however, the peroxidisability index (PI) and iodine value (IV) were less favourable compared with local pigs. Consumers evaluated cooked loins and baked bellies. The loins from local breeds scored higher in juiciness, taste and overall acceptability compared with conventional hybrids. However, a higher overall acceptability was observed for the lean bellies of hybrids. The results can be used to increase pork consumption choices.

Comparison of the Pig Breeds in the Small Intestinal Morphology and Digestive Functions at Different Ages.

The small intestine is the main site for digestion and absorption of nutrients, and the development of the small intestine can be affected by several factors, such as diet composition, age, and genotype. Thus, this study aimed to compare the small intestinal morphology and digestive function differences at different ages of three pig breeds. Thirty litters of newborn Taoyuan black (TB), Xiangcun black (XB), and Duroc (DR) piglets (ten litters per breed) were selected for this study. Ten piglets from each breed were selected and sampled at 1, 10, 21, and 24 days old. The results showed that the TB and XB piglets had lower growth but had higher lactase and maltase activities in the jejunum compared with the DR piglets, while most of the digestive enzyme activities in the ileum were higher in the DR piglets at different ages. The expression levels of nutrient transporters, mainly including amino acids, glucose, and fatty acids transporters, differed in the jejunum at different ages among three pig breeds and were higher in the DR piglets at 1 day old and XB piglets at 24 days old. Collectively, these findings suggest that the phenotypic differences in the growth, intestinal morphology, and digestive function among the three pig breeds mainly resulted from the differences in digestive enzymes and nutrient transporters in the intestine.

Genotype and dietary lysine deficiency affect carcass and muscle amino acid composition of pigs growing from 10 to 25 kg body weight.

Amino acid (AA) composition of body protein is considered constant although there are evidences that AA pattern in pigs may be altered by different factors. Pigs with different body composition and protein deposition rates-like fatty and lean pigs-may differ in AA composition, with possible consequences on their AA requirements. This work investigates effects of genotype and dietary lysine deficiency on AA composition of carcass and muscles of Iberian and Landrace × Large White pigs. Twenty-eight barrows (10 kg body weight [BW]), 14 from each breed, were used. They were randomly assigned to two experimental diets according to a factorial arrangement (two breeds × two diets). Diets were isonitrogenous and isoenergetic (200 ± 1 g CP/kg dry matter (DM); 14.7 ± 0.1 MJ ME/kg DM) and with identical chemical composition except for lysine concentration (10.9 and 5.20 g lysine/kg DM, for lysine-adequate (AL) diet and lysine-deficient (DL) diet respectively). Pigs were individually housed, and daily feed allowance was adjusted on a weekly basis according to BW. Pigs were slaughtered at 25 kg BW. Isoleucine, valine and phenylalanine concentration were higher in carcass protein of Iberian pigs (p < .01). In longissimus muscle, higher concentration of arginine, isoleucine, phenylalanine, lysine and valine (p < .001-p < .05), and lower of methionine (p < .001) were detected in Iberian pigs, whereas phenylalanine, leucine, lysine, threonine and methionine concentration decreased and arginine increased (p < .001-p < .05) when pigs were fed DL diet. Genotype and lysine deficiency effects were moderate in the AA composition of protein of biceps femoris muscle. The results show that AA proportions in protein of carcass and longissimus muscle can be influenced by pig genotype and conditions of lysine shortage. The biceps femoris muscle, with different functional and metabolic properties, shows more constant AA composition than longissimus, which seem to prevail independent from genotype or nutritional challenges.

Effects of lysine deficiency on carcass composition and activity and gene expression of lipogenic enzymes in muscles and backfat adipose tissue of fatty and lean piglets.

The purpose of this study was to investigate potential mechanisms involved in fat deposition promoted by dietary lysine deficiency, particularly intramuscular fat (IMF), and differential responses between fatty and lean pigs. Carcass traits and lipogenic enzyme activities and gene expression levels in muscles and adipose tissue were investigated in Iberian (fatty) and Landrace × Large White (LDW) pigs under identical feeding level (based on body weight (BW)) and management conditions. Twenty-eight barrows of 10 kg initial BW, 14 per breed, were fed two isoproteic (200 g CP /kg DM) and isocaloric (14.7 MJ metabolizable energy/kg DM) diets with identical composition except for the lysine content (1.09% for diet adequate in lysine and 0.52% for diet deficient in lysine). At a BW of 25 kg, pigs were slaughtered. Compared with pigs fed the lysine-adequate diet, in both genotypes lysine-deficient diet led to lower carcass protein concentration, lower relative proportions of leaner components (loin, ham and shoulder; P < 0.01), and higher carcass fatty components and carcass lipid concentration (P < 0.001). Irrespective of diet, the activity and gene expression of lipogenic enzymes (fatty acid synthase (FAS), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G6PDH)) were greater in Iberian than in LDW pigs, particularly in adipose tissue where transcriptional regulators involved in the control of adipogenesis and lipogenesis were also upregulated in Iberian animals. In backfat tissue, there was a small decrease induced by or no effects of lysine-deficient diet on the activity and gene expression of lipogenic enzymes, nor in gene expression levels of upstream regulators of lipogenesis and adipogenesis. In longissimus muscle, the activity of FAS, G6PDH and ME increased with lysine deficiency in both genotypes (P < 0.01) and an upregulation of gene expression of lipogenic enzymes was specifically observed in Iberian pigs (P < 0.05 to P < 0.001). In biceps femoris muscle of lysine-deficient pigs, the activity of FAS and ME enzymes increased, ME1 gene was upregulated (added to FASN gene in the case of Iberian pigs; P < 0.01 to P < 0.001) and PPARA gene was downregulated (P < 0.05). The results show that in both fatty and lean pigs, the effect of lysine deficiency on lipid metabolism was tissue-specific, with an activation of lipogenesis in longissimus and biceps femoris muscle but no apparent stimulation in backfat adipose tissue. Suitable feeding protocols including lysine-deficient diets should be designed for each pig type in order to increase intramuscular lipids without penalizing the growth of lean carcass components.

Occurrence, clinical involvement and zoonotic potential of endoparasites infecting Swiss pigs.

In order to estimate the diversity, clinical involvement and zoonotic potential of parasites in pigs submitted for diagnosis to the PathoPig project of the Swiss Federal Food Safety and Veterinary Office, faeces (n=125) from suckling piglets (n=39), weaners (n=60) and piglets beginning fattening (n=26) from 74 Swiss farms were examined by 3 coproscopical methods (i.e. sedimentation/zinc chloride-flotation; SAFC and Ziehl-Neelsen staining). Samples microscopically positive for Cryptosporidium were further tested by PCR/sequencing for species assessment. The most frequently detected parasite was Balantidium coli, a facultative pathogenic ciliate with zoonotic potential, in 5.1, 36.7 and 50.0% of suckling, weaners and fatteners and 43.2% of farms; however, no association with disease was observed. Isospora (syn. Cystoisospora) suis infections were detected in 13.3 and 11.1% of suckling piglets with and without diarrhoea, and in 10.0 and 13.3% of weaners and fatteners with diarrhoea, respectively, and were significant associated with emaciation. Cryptosporidium infections were detected in 10.3, 15.0 and 19.2% of sucklings, weaners and fatteners, respectively, and in 18.9% of the farms. Interestingly, two age-related species were identified: C. suis in younger piglets (2 to 6weeks) and C. scrofarum in older ones (6 to 17weeks). None of the pigs infected with C. scrofarum (n=8), but 3 of 4 piglets infected with C. suis (co-infection with I. suis in 2 cases) had diarrhoea. The zoonotic species C. parvum was not detected, nevertheless, sporadic cases of human infection with the porcine-adapted species have been reported. Ascaris suum, Trichuris suis and Strongylida were rarely detected (<4%) in all age categories.

Restriction of dietary protein does not promote hepatic lipogenesis in lean or fatty pigs.

The influence of genotype (lean v. fatty) and dietary protein level (normal v. reduced) on plasma metabolites, hepatic fatty acid composition and mRNA levels of lipid-sensitive factors is reported for the first time, using the pig as an experimental model. The experiment was conducted on forty entire male pigs (twenty lean pigs of Large White×Landrace×Pietrain cross-breed and twenty fatty pigs of Alentejana purebreed) from 60 to 93 kg of live weight. Each pig genotype was divided into two subgroups, which were fed the following diets: a normal protein diet (NPD) equilibrated for lysine (17·5 % crude protein and 0·7 % lysine) and a reduced protein diet (RPD) not equilibrated for lysine (13·1 % crude protein and 0·4 % lysine). The majority of plasma metabolites were affected by genotype, with lean pigs having higher contents of lipids, whereas fatty pigs presented higher insulin, leptin and urea levels. RPD increased plasma TAG, free fatty acids and VLDL-cholesterol compared with NPD. Hepatic total lipids were higher in fatty pigs than in the lean genotype. RPD affected hepatic fatty acid composition but had a slight influence on gene expression levels in the liver. Sterol regulatory element-binding factor 1 was down-regulated by RPD, and fatty acid desaturase 1 (FADS1) and fatty acid binding protein 4 (FABP4) were affected by the interaction between genotype and diet. In pigs fed RPD, FADS1 was up-regulated in the lean genotype, whereas FABP4 increased in the fatty genotype. Although there is a genotype-specific effect of dietary protein restriction on hepatic lipid metabolism, lipogenesis is not promoted in the liver of lean or fatty pigs.

Age-related infection with Cryptosporidium species and genotype in pigs in China.

OBJECTIVE: Pigs, as hosts of zoonotic Cryptosporidium species/genotypes, are domestic animals with public health significance. The present study was to characterize the infection rate and species/genotype of Cryptosporidium in pre-weaned and post-weaned pigs from Shanghai and Shaoxing, China. METHODS: A total of 208 fecal samples (42 from pre-weaned piglets, and 166 from post-weaned pigs) were examined by nested PCR of the 18S rRNA gene and analyzed by phylogenetic DNA fragment sequencing of secondary PCR products. RESULTS: Infection was detected in 79 samples (19/42 pre-weaned piglets, and 60/166 post-weaned pigs). C. suis (14/79) and Cryptosporidium pig genotype II (65/79) were identified; piglets were more susceptible to the former (13/14) and post-weaned pigs to the latter (59/65). CONCLUSION: Infection of Cryptosporidium spp. in pigs was age-specific; piglets were more susceptible to C. suis while pigs were more susceptible to Cryptosporidium pig genotype II. These findings combined with the isolation of the two Cryptosporidium from water suggest that pigs may be a source of zoonotic Cryptosporidium water pollution. Improvements in pig feeding practices, sewage discharge, feces disposal and field worker protection are therefore important to prevent potential public health problems.