Effects of dietary lysine/protein ratio and fat levels on growth performance and meat quality of finishing pigs

Changes in the Objective Indices Related to Meat Quality of Porcine Longissimus Dorsi Induced by Different Thawing Methods

The quality of frozen pork is adversely affected upon thawing. In this study, the influence of various thawing methods for frozen pork, including cold water (18 °C), room temperature (18 °C), and refrigeration (4 °C) thawing, on physicochemical and nutrient substances were examined. The pork samples (a Chinese local breed: Anqing six-end-white pigs), which were thawed through the above conditions, were compared with controls (fresh porcine longissimus dorsi). Analyses were carried out to determine porcine longissimus dorsi shear force, pH value, crude protein content, antioxidant capacity, amino acid content, and fatty acid content. The results indicated that the shear force, pH value, crude protein content, total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) content of the porcine longissimus dorsi muscle significantly decreased via the three thawing methods compared with the control group (p < 0.05). However, malondialdehyde (MDA) content, intramuscular fat content, inosinate and cholesterol content, essential amino acid content, and umami amino acid proportion in the cold thawing group were not significantly different from the control group (p > 0.05), but there were significant differences between the other two groups. The MDA content of the air thawing and hydrostatic thawing groups significantly increased compared with the control group (p < 0.05), with it being 42.6% and 50.8% higher than the control group, respectively. In addition, the monounsaturated fatty acid content in the pork subjected to the three thawing methods significantly increased compared with the control group (p < 0.05), and the monounsaturated fatty acid content after cold thawing and hydrostatic thawing increased by 18.2% and 21.6%, respectively. In conclusion, refrigeration had less influence on the quality of the Anqing six-end-white pork and was the most suitable thawing method. This study provides a theoretical reference for frozen pork preservation for improving food quality and availing its economic benefits.

Influence of Fermented Broccoli Residues on Fattening Performance, Nutrient Utilization, and Meat Properties of Finishing Pigs

The study determined the impacts of dietary fermented residues' (FBR) inclusion on growth, nutrient utilization, carcass characteristics, and meat properties in fattening pigs. Seventy-two robust pigs were randomly assigned to two experimental groups (Duroc × Landrace × Yorkshire, thirty-six pigs each). Each group was subjected to a 52-day trial, during which they received either a corn-soybean meal-based diet or diet enhanced with a 10% addition of FBR. Consequently, adding 10% FBR caused a significant decrease in the digestive utilization of crude dietary components in fattening pigs (p < 0.05) but showed no significant impact on the growth performance. Additionally, FBR inclusion increased the marbling scores (p < 0.05) and total antioxidant functions (p < 0.05) of muscle tissues, indicating improved meat quality. Gender affected backfat depth, with barrows showing thicker backfat depth. In conclusion, dietary supplementation with 10% FBR in finishing pigs influenced the meat quality by improving the marbling score and antioxidant performance while reducing digestibility without compromising growth performance.

Genetic parameters for carcass and meat quality traits in Jinhua, Duroc, and their crossbred pigs

Jinhua pigs have excellent meat quality and intramuscular fat content (IMF). Crossbreeding of Jinhua with Duroc pigs with high productivity was conducted to develop a new composite breed that possesses the beneficial characteristics of both breeds. The objective of this study was to estimate the crossbreeding parameters (additive breed, dominance, and epistatic loss effects) using the Kinghorn model and genetic parameters (heritability and genetic correlation) for carcass and meat quality traits by analysing the phenotypic data of Jinhua, Duroc, and their crossbred pigs. Backfat thickness at the thinnest point above the 9th to 13th thoracic vertebrae (BF), longissimus muscle area between the 4th and 5th thoracic vertebrae (LMA), meat shear force value (SFV), and IMF were measured. The additive breed effects were significant for all traits: 1.59 cm, -8.30 cm2 , -6.38 lb/cm2 , and 1.76% for BF, LMA, SFV, and IMF, respectively. The dominance effect was significant for LMA (7.41 cm2 ) and IMF (-2.46%), whereas the epistatic loss effect was significant for only LMA (-15.18 cm2 ). The estimated heritability values were high, ranging from 0.58 for IMF to 0.76 for LMA. A negative but non-significant genetic correlation of -0.11 was estimated between BF and IMF; however, previous studies have reported that the genetic correlation between these traits is moderately positive in modern western pigs. Our results imply that, with the estimation of crossbreeding and genetic parameters, genetic improvement could be implemented to produce a new composite breed with good meat quality and productivity, to meet Japanese market requirements, by crossbreeding Jinhua and Duroc pigs.

Effects of dietary protein levels on production performance, meat quality and flavor of fattening pigs

This study aimed to evaluate the effects of dietary protein level on the production performance, slaughter performance, meat quality, and flavor of finishing pigs. Twenty-seven Duroc♂ × Bamei♀ binary cross-bred pigs (60.86 ± 2.52 kg body weight) were randomly assigned to three groups, each group has three replicates, and each replicate has three pigs. Three groups of finishing pigs were fed 16.0, 14.0, and 12.0% crude protein levels diets, and these low-protein diets were supplemented with four limiting amino acids (lysine, methionine, threonine and tryptophan). The results showed that the pigs fed low-protein diets increased (P < 0.05) loin eye muscle area, and reduced (P < 0.05) heart weight, lung weight. The feed-weight ratio of the 14.0% protein group was reduced (P > 0.05); Dietary protein levels significantly affected the luminance (L_24h), yellowness (b_45min and b_24h) (P < 0.05), reduced shear stress, muscle water loss, drip loss, the levels of crude fat (P < 0.05), and increased marbling score (P < 0.05) in the muscle of finishing pigs; The low-protein diets improved PUFA/TFA, PUFA/SFA (P > 0.05), and increased hexanal, E-2-heptenal, 1-octen-3-ol, EAA/TAA in the muscle of finishing pigs (P < 0.05); The results indicated that reduced the crude protein levels of dietary by 2.0–4.0%, and supplementation with four balanced limiting amino acids had no significant effects on the production performance and slaughter performance of finishing pigs, and could effectively improve meat quality and flavor.

Improvement of Intramuscular Fat in longissimus Muscle of Finishing Thai Crossbred Black Pigs by Perilla Cake Supplementation in a Low-Lysine Diet

This study was conducted to find out the effects of perilla cake (PC) supplementation in a low-lysine diet on Thai crossbred finishing pigs’ productivity, carcass and meat quality, and fatty acid composition. For six weeks, a total of 21 barrows of finishing pigs were fed with three dietary treatments (T1: basal diet, T2: 2.5 percent PC supplementation in a low-lysine diet, and T3: 4.5 percent PC supplementation in a low-lysine diet). The results show that the intramuscular fat and marbling score was significantly increased by T2 and T3. On the other hand, it was found that the boiling loss and shear force value were significantly decreased by T2 and T3 (p < 0.05). In a low-lysine diet, dietary PC supplementation caused a significant increase in malondialdehyde levels in meat (p < 0.05) compared with the basal diet. It was also shown that alpha-linolenic acid level in backfat and the longissimus thoracis et lumborum muscle was increased considerably by T2 and T3. Therefore, supplementing PC in a low-lysine diet may be an alternative strategy for improving the meat quality of late-phase pigs.

iTRAQ-mediated analysis of the relationship between proteomic changes and yak longissimus lumborum tenderness over the course of postmortem storage

To identify differentially expressed proteins associated with energy metabolism and tenderness during the postmortem aging of yak longissimus lumborum muscle samples, we collected tissue samples from yaks raised at different altitudes. At 12 h post-slaughter, we identified 290 differentially expressed proteins (DEPs) in these samples, whereas 436 such DEPs were detected after 72 h. Identified DEPs were clustered into four main functional categories: cell structural proteins, glycogen metabolic proteins, energy reserve metabolic proteins, and cellular polysaccharide metabolic proteins. Further bioinformatics analysis revealed that these proteins were associated with carbon metabolism, glycolysis, and the biosynthesis of amino acids. Our functional insights regarding these identified proteins contribute to a more detailed molecular understanding of the processes of energy metabolism in yak muscle tissue, and represent a valuable resource for future investigations.

Comparison of growth performances, carcass characteristics, and meat qualities of Okinawan indigenous Agu pigs and crossbred pigs sired by Agu or Duroc boar

Indigenous Okinawa Agu pigs are crossed with Large White × Landrace (WL) pigs to improve their meat production, but there is little information regarding the crossbreeding effects. The study aims to compare growth, carcass characteristics, and meat qualities of Agu pigs with those of WL crossbreeds with Agu sires (WLA) or Duroc sires (WLD). WLA pigs showed better growth performance and carcass characteristics and less intramuscular fat (IMF) contents than Agu ones, but they had higher fat deposition, smaller longissimus dorsi muscle area, and higher IMF contents than WLD pigs. Agu pigs showed higher water holding capacity than the other two breeds. The inner layer of Agu backfat contains higher and lower proportions of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acid (PUFA), respectively, than that in WLD animals. WLA animals had intermediate values for the fatty acid content in the inner backfat, although MUFA contents were equal to those of Agu pigs. Fatty acid profiles in IMF were similar to those in the backfat. These results indicate that crossbreeding of Agu with WL pigs improves growth performance and carcass quality. Particularly, WLA pigs have higher IMF contents and MUFA concentrations and lower PUFA concentrations than WLD pigs.

Integrating RNA-sequencing and untargeted LC-MS metabolomics to evaluate the effect of lysine deficiency on hepatic functions in Holstein calves

Lysine (Lys) is majorly metabolized in the liver. The liver functional consequences of a dietary Lys deficiency in young Holstein calves are unknown. This study aimed to investigate the effects of Lys deficiency in Holstein calf livers using RNA-sequencing and untargeted LC-MS metabolomics. Calves (n = 36; initial body weight 101.2 ± 10.8 kg; 90-day-old) were fed restricted diets, for 90 days, containing 19.2% crude protein that varied in Lys content (PC group 1.21%; PC-Lys group 0.85%; dry matter basis) for 90 days. Body weight, average daily gain, gain/feed, and Lys intake were significantly decreased in response to Lys deficiency (P < 0.05). Dry matter intake was not altered (P > 0.05). Network and pathway analyses revealed that noradrenaline, adenosine 5'-monophosphate, acetyl-CoA, and coenzyme A were significantly decreased. Regulating of lipolysis in adipocytes pathway and fatty acid degradation pathway were downregulated. We also identified eight significantly differentially expressed genes (SDEGs), among which adrenoceptor beta 2 (ADRB2), WAP four-disulfide core domain 2 (WFDC2), and claudin-4 (CLDN4) were associated with inhibition of lipolysis, and carbon catabolite repression 4-like (CCRN4L), FOS like 2 (FOSL2), and arginase 2 (ARG2) were associated with inhibiting lipid synthesis. Correlation tests showed that coenzyme A was strongly correlated with SDEGs (0.82 ≤|r|≤ 0.96). Acetyl-CoA and adenosine 5'-monophosphate were strongly correlated with CCRN4L (0.90 ≤|r|≤ 0.92), indicating a strong correlation between the changes in SDEGs and these metabolites. In conclusion, Lys deficiency caused dysplasia and affected lipid metabolism in the liver by inhibiting lipolysis and lipid synthesis in calves.

Effects of dietary crude protein levels and cysteamine supplementation on meat quality and related indices of finishing pigs

The aim of this study was to investigate the effects of dietary crude protein levels and cysteamine (CS) supplementation on meat quality and related indices in longissimus dorsi muscle of finishing pigs. One hundred and twenty barrows were randomly allocated to a 2 × 2 factorial arrangement with five replicates of six pigs each. The primary variations were crude protein levels (14% or 10%) and CS supplemental levels (0 or 140 mg kg−1). After 41 d, 10 pigs per treatment were slaughtered. The results showed that low-protein level diets (LPDs) decreased Warner–Bratzler shear force (P < 0.01) and increased the content of intramuscular fat (P < 0.01). The mRNA expressions of lipogenic genes were up-regulated (P < 0.01), and the mRNA expressions of lipolytic genes were down-regulated (P < 0.01) in pigs fed LPD. LPDs increased the mRNA expressions of μ-calpain, and decreased the mRNA expression of calpastatin (P < 0.01). In addition, CS supplementation increased the mRNA expression of μ-calpain (P < 0.01). In conclusion, LPD improved the meat quality probably through regulating the lipogenesis, lipolysis, and the proteolysis process in muscle. The CS supplementation did not affect the meat quality of finishing pigs. Moreover, no significant interaction between dietary protein levels and CS supplementation for the meat quality of finishing pigs was observed.

Effect of dietary kapok oil supplementation on growth performance, carcass traits, meat quality and sensory traits of pork in finishing-pigs

Kapok seed and oil from the tropical zone are widely used as pig feed to harden porcine fat in Japan. This study evaluated the effect of dietary kapok oil supplementation on pork quality and sensory traits. Five Duroc pigs each were assigned to an experimental group supplemented with kapok oil and a control group. Dietary kapok oil supplementation had no effect on growth performance and intramuscular fat content in the Longissimus dorsi muscle (LM). Supplemental kapok oil increased saturated fatty acid contents in subcutaneous and intramuscular fat and decreased monounsaturated fatty acid levels (P < 0.05). Off-flavor detection by a trained panel was higher in the experimental than the control group (P < 0.05), but tenderness, juiciness, texture and flavor intensity of LM chops were similar in both groups. The overall palatability of pork as judged by a consumer panel decreased with kapok oil supplementation (P < 0.01). These results indicate that while growth performance, intramuscular fat contents and carcass characteristics were unchanged, while dietary kapok oil supplementation makes firm fat to prevent inferior soft fat in pork, it can lower the palatability of pork due to a decrease in monounsaturated fatty acids.

Effect of including sweet potato (Ipomoea batatas Lam) meal in finishing pig diets on growth performance, carcass traits and pork quality

The partial replacement of a commercial concentrate at 10-20% and 15-30% (the first percentage of each dietary treatment corresponded to weeks 1-3 and the second to weeks 4-7 of the experiment, respectively) by sweet potato meal (SPM; 70% foliage: 30% roots) was evaluated for growth performance, carcass yield, instrumental and sensory pork quality using 36 commercial crossbred pigs (56.8 ± 1.3 kg initial body weight). Three dietary treatments were compared in a randomized complete block design. Most growth, carcass traits and pork quality variables were not affected by the SPM inclusion. Growth performance averaged 868 g/day and feed efficiency 0.24 kg/kg. However, feed intake increased 2.2% (P = 0.04) in pigs fed the 10-20% SPM diets, in a similar order of magnitude as the decrease in dietary energy. Despite an increase in gastrointestinal tract as a percent of hot carcass weight (+14.7%) (P = 0.03) with SPM inclusion, carcass yield averaged 69.4%. Conversely, decreases in loin yield (-4.2%) (P = 0.05), backfat thickness (-6.0%) (P < 0.01) and pork tenderness (-13%) (P = 0.02) were observed with 15-30% SPM inclusion. Results suggest that up to 20% SPM inclusion is a viable feed strategy for finishing pigs, easily replicable in small farm settings. © 2016 Japanese Society of Animal Science.