Effects of electrical stimulation and pre‐rigor conditioning temperature on aging potential of hot‐boned beef M. longissimus lumborum

The objective of this study was to create various pH/temp decline rates in hot‐boned bull beef M. longissimus lumborum (LL) through a combination of electrical stimulation (ES) and pre‐rigor holding temperature. The relationship between the pre‐rigor interventions, the activities of µ‐calpain and small heat shock proteins (sHSP), and the impacts on meat product quality were determined. Paired LL loins from 13 bulls were hot‐boned within 40 min of slaughter, immediately ES and subjected to various holding temperatures (5, 15, 25, and 35°C) for 3 hr. The rate of muscle pH decline, sarcomere length, shear force, and proteolysis of muscle proteins were measured. ES‐25°C had a longer sarcomere length compared to non‐electrical stimulation samples. ES‐25°C and ES‐35°C samples had lower shear force values, higher µ‐calpain activity and higher desmin, troponin‐T, and sHSP degradation. The above findings suggest that pH/temp decline rates created in hot‐boned muscle impacted muscle protein proteolysis by increasing the activity of proteases and degradation of sHSP.     

Physico‐chemical characteristics of Longissimus lumborum muscle in goats subjected to halal slaughter and anesthesia (halothane) pre‐slaughter

This study assessed the effect of halal slaughter and anesthesia pre‐slaughter followed by bleeding on meat quality characteristics of goats. Eleven male Boer cross goats were divided into two groups and subjected to either halal slaughter (HS) or anesthesia with halothane and propofol pre‐slaughter (AS). At pre‐rigor, HS had significantly lower (P < 0.05) muscle pH and glycogen than AS. However, no significant difference was observed in the pH and glycogen content between the treatments on 1, 3 and 7 days post mortem. The drip loss of HS was significantly lower (P < 0.05) than that of AS at all aging periods. Treatment had no effect on sarcomere length, myofibrillar fragmentation index and shear force values, loss of thiol groups and degradation of major myofibrillar proteins. It can be concluded that HS did not have deleterious effect on meat quality traits of goat when compared to AS.     

Changes of microbial spoilage,lipid‐protein oxidation and physicochemical properties during post mortem refrigerated storage of goat meat

Examined was the effect of post mortem refrigerated storage on microbial spoilage, lipid‐protein oxidation and physicochemical traits of goat meat. Seven Boer bucks were slaughtered, eviscerated and aged for 24 h. The Longissimus lumborum (LL) and Semitendinosus (ST) muscles were excised and subjected to 13 days post mortem refrigerated storage. The pH, lipid and protein oxidation, tenderness, color and drip loss were determined in LL while microbiological analysis was performed on ST. Bacterial counts generally increased with increasing aging time and the limit for fresh meat was reached at day 14 post mortem. Significant differences were observed in malondialdehyde (MDA) content at day 7 of storage. The thiol concentration significantly reduced as aging time increased. The band intensities of myosin heavy chain (MHC) and troponin‐T significantly decreased as storage progressed, while actin remained relatively stable. After 14 days of aging, tenderness showed significant improvement while muscle pH and drip loss reduced with increase in storage time. Samples aged for 14 days had higher lightness (P < 0.05) and lower (P < 0.05) yellowness and redness. Post mortem refrigerated storage influenced oxidative and microbial stability and physico‐chemical properties of goat meat.     

Assessment of calpain and caspase systems activities during ageing of two bovine muscles by degradation patterns of αII spectrin and PARP‐1

The activities of calpain and caspase systems during ageing in Longissimus lumborum (LL) and Infraspinatus (IS) muscles of Italian Simmental young bulls (Bos taurus) were assessed. Samples from 10 animals were collected within 20 min of exsanguination (T0), after 48 h (T1) and 7 days (T2) post mortem. Calpain and caspase activity were evaluated based on the formation of αII spectrin cleavage products of 145 kDa (SBDP145) and 120 kDa (SBDP120), respectively. Caspase activity was also assessed by the presence of poly (adenosine diphosphate‐ribose) polymerase‐1 (PARP‐1) cleavage product. At T0, LL showed higher levels of SBDP145 than IS (P < 0.01), while SBDP120 and PARP‐1 degradation products were similar between muscles. At T1, no difference was found in the level of SBDP145 between muscles, while SBDP120 and PARP‐1 cleavage products were not detected. At T2 neither αII spectrin nor PARP‐1 cleavage products were found. LL and IS showed different proteolysis after slaughter that was influenced more by calpain than caspase activity, which was detectable only in the early post mortem period.     

Involvement of μ/m‐calpain in the proteolysis and meat quality changes during postmortem storage of chicken breast muscle

The objective of this study was to investigate the role of calpain isotypes, especially poultry‐specific μ/m‐calpain in the proteolysis and meat quality changes of chicken breast muscle during postmortem storage. Calpain activity was detected by casein zymography, while the degradation of titin, desmin and Troponin‐T was analyzed by sodium dodecyl sulfate – polyacrylamide gel electrophoresis and western blot. Meat quality indicators such as water holding capacity and tenderness were also studied. The correlation analysis between calpain activity, proteolysis and the changes in meat quality indicators indicated that there were strong correlations for μ‐calpain during the first 12 h of storage, while such strong correlations for μ/m‐calpain were only found in samples stored from 12 h to 7 days. Our study suggested that μ‐calpain played a major role in meat quality changes while μ/m‐calpain could also be involved but played a limited role in the proteolysis and meat quality changes during 12 h to 7 days postmortem storage of chicken breast muscle.     

Effects of dietary oil blend on fatty acid composition,oxidative stability and physicochemical properties of Longissimus thoracis et lumborum muscle in goats

This study examined the effects of dietary blend of 80% canola oil and 20% palm oil (BCPO) on the physicochemical properties, antioxidant status, oxidative stability and fatty acid composition of Longissimus thoracis et lumborum (LTL) muscle from goats during chill storage. Over a 14‐week feeding trial, 24 Boer bucks were randomly assigned to and supplemented with diets containing 0, 4 or 8% BCPO on a dry matter basis, slaughtered and the LTL was subjected to a 7 day chill storage. Neither diet nor post mortem ageing influenced (P > 0.05) antioxidant enzyme activities, chemical composition and cholesterol. Diet had no effect on the carbonyl content, free thiol content, water‐holding capacity, tenderness, pH and glycogen. Oil‐supplemented goats had higher (P < 0.05) C18:1 trans‐11, C18:3n‐3 and C20:5n‐3, carotenoid, tocopherol and redness, and lower thiobarbituric acid reactive substances values than the control goats. Post mortem ageing decreased (P < 0.05) shear force and oxidative stability of chevon. No significant (P > 0.05) changes were found in the proportion of individual fatty acids throughout storage. Total polyunsaturated fatty acids (PUFA) decreased while total saturated fatty acids increased as storage progressed. Dietary BCPO enhanced n‐3 PUFA without compromising the quality attributes of chevon.     

Polysaccharides from Acanthopanax senticosus enhances intestinal integrity through inhibiting TLR4/NF‐κB signaling pathways in lipopolysaccharide‐challenged mice

To investigate the role of polysaccharide from Acanthopanax senticosus (ASPS) on lipopolysaccharide (LPS)‐induced intestinal injury, mice in three treatments were administrated orally with or without ASPS (300 mg/kg body weight) for 14 days, followed by challenge with LPS or saline. At 4 h post‐injection, blood and intestinal samples of six mice / treatment were collected. The results showed ASPS ameliorated LPS‐induced intestinal morphological deterioration, proven by improved villus height (P < 0.05) and villus height : crypt depth ratio (P < 0.05). ASPS also elevated the mucosal barrier of LPS‐challenged mice, supported by reduced plasma diamine oxidase (DAO) activity (P < 0.05) and L‐lactate (P < 0.05), increased mucosal DAO activity (P < 0.05) as well as enhanced intestinal tight junction proteins expression involving occludin‐1 (P < 0.05) and zonula occludens‐1 (P < 0.05). In addition, ASPS decreased LPS‐induced secretion of inflammatory mediators, including tumor necrosis factor (TNF)‐α (P < 0.05) and prostaglandin E₂ (P < 0.05). Also, ASPS down‐regulated messenger RNA expression of toll‐like receptor 4 (TLR4) and its downstream signals, including myeloid differentiation factor 88 (P < 0.05), TNF‐α receptor‐associated factor 6 (P < 0.05), as well as nuclear factor (NF)‐κB p65 (P < 0.05) and its protein expression. These findings suggest that ASPS improves intestinal integrity under inflammation conditions connected with inhibiting TLR4/NF‐κB signaling pathways.     

Changes in water‐holding capacity and textural properties of chicken gizzard stored at 4°C

The water‐holding capacity (WHC), and toughness (shear force) of chicken gizzard were evaluated during postmortem storage for 4.5, 7, 12, 24, 48, 72 and 96 h at 4°C. Degradation of the cytoskeletal proteins desmin, talin and vinculin were monitored by sodium dodecyl sulfate – polyacrylamide gel electrophoresis and Western blotting during the same designated storage period. The WHC of the gizzards decreased significantly from 12 h to 72 h of storage, but by 96 h the WHC was restored to the level measured after storage for 12 h. The shear force value of the gizzards increased rapidly until 12 h and then decreased until 24 h, with a further slight decrease by 48 h. Degradation products of desmin, talin and vinculin appeared at 96 h, 12 h and 48 h postmortem, respectively. The intensity of immunolabeling for desmin, talin and vinculin after storage for 96 h decreased to 51%, 25% and 52% of the initial value. The appearance of desmin degradation products was accompanied by an increase in WHC. This suggests that the postmortem degradation of desmin is involved in the increase of WHC in chicken gizzard during storage at 4°C, and talin and vinculin may be involved.     

Effects of concentrate levels on fattening performance, carcass and meat quality attributes of Small East African × Norwegian crossbred goats fed low quality grass hay

To assess the effects of finishing Small East African × Norwegian crossbred goats with concentrate diets on the fattening performance, carcass and meat quality, 32 castrated crossbred goats (9.5 months old, 17.1 kg BWT) were equally allocated into four levels of concentrate supplementation. The concentrate levels were: Zero access to concentrate (T0), 33% access to ad libitum concentrate allowance (T33), 66% access to ad libitum concentrate allowance (T66) and 100% access to ad libitum concentrate allowance (T100). Each animal had access to ad libitum grass hay. Ad libitum concentrate intake for the goats was 663 g/d, which supported ME intake of 8.7 MJ/head/d. The attained maximum daily gain was 96 g/d. T100 and T66 goats were comparable in slaughter weight but the former had 2 kg heavier (P < 0.05) carcasses than the latter. T100 and T66 goats were similar in carcass fatness scores, though both were fattier (P < 0.05) than other diet groups. Dressing percentage (DP) was expressed in three different ways. In all but commercial DP, T100 were comparable to T66 goats, but all were higher than the other diet groups. For T0 goats, pH-values remained above 6 even after 24 h post-mortem. Cooking losses increased (P < 0.05) with increasing levels of concentrate supplementation. Moreover, among the muscles assessed, M. rectus abdominis had the least cooking loss. Warner–Bratzler shear force values of cooked muscles were highest (P < 0.05) in M. gluteobiceps, followed by M. vastus lateralis, while M. psoas major and longismus dorsi aged for 6 days had the least values. Finishing Small East African × Norwegian crossbred goats at 66% access to their ad libitum concentrate intake gives optimum carcass and meat quality, and that any increase above this level seems not to improve meat production.     

Comparison of the effects of different transport conditions and lairage times in a Mediterranean climate in South Africa on the meat quality of commercially crossbred Large white x Landrace pigs

Information on the effect of road transportation conditions and lairage times on the meat quality of pork under South African conditions is very sparse. In this investigation, the effects of 2 road conditions (rough road with frequent stops - A; smooth road, few stops - B) and 2 lairage holding periods (2 h and 24 h) on the physical meat quality attributes of commercially produced pigs during summer (ambient temperatures > 30 degrees C) in the Western Cape (South Africa) were investigated. Pig meat from pigs transported on a road that caused more stress (A), had lower pH 45 (measured 45 min post mortem) values after 2 h lairage than pigs transported over a smoother road. Pigs B had a lower muscle pH 24 (measured 24 h post mortem) than group A, indicating that they had more glycogen reserves available for post mortem glycolysis. Road conditions A were more stressful resulting in a higher incidence of PSE pork, as shown by the percentage drip loss and the L* values. When the lairage period was increased to 24 h prior to slaughter, pigs transported under road conditions A had time to replenish their energy reserves and the pH 45, drip loss and L* values were within an acceptable range. However, pigs transported under road conditions B had lower pH 45 and higher pH 24 values, indicating that the lairage period was too long and that energy reserves were depleted in order to adapt to the stressful conditions. Results from this investigation indicate that improvement of the transport/road conditions will result in better pork quality.     

Influence of ante‐ and peri‐mortem factors on biochemical and physical characteristics of turkey breast muscle

Summary

The course of post‐mortem breakdown of glycogen and ATP in turkey pectoralis major muscle was markedly influenced by several ante‐ and peri‐mortem variables. Application of a proper stunning procedure was highly effective in preventing peri‐ and post‐mortem muscle stress reactions.

The physiological level of glycogen and ATP was not significantly affected by road transportation covering 260 km. Birds which rested for 24 hrs following transportation had lower glycogen and ATP levels at the moment of slaughter than non‐rested birds.

According to the changes in the rate and extent of post‐mortem biochemical reactions, several meat characteristics such as water‐holding capacity, colour, and tenderness were significantly changed.

Furthermore, the results also indicate that turkey breast muscle is susceptible to a PSE‐like condition as described in pork.     

Effects of 2‐hydroxy‐4‐(methylthio) butanoic acid isopropyl ester on growth and blood components in growing Holstein steers

Twenty‐four Chinese Holstein growing steers were randomly divided into three groups and fed a diet containing 0 (the control group), 15 (treatment I group, or TG1) or 25 (treatment II group, or TG2) g/day 2‐hydroxy‐4‐(methylthio) butanoic acid isopropyl ester (HMBi). Compared with the control group, the final body weights, total gains and average daily gains in the treatment groups increased (P < 0.01). The concentration of total protein (TP) for TG1 increased (P < 0.01). The levels of albumin in TG1 were higher than those in TG2 and the control group (P < 0.05). The concentration of alanine aminotransferase (ALT) in TG2 increased (P < 0.05), but concentrations of aspartate aminotransferase (AST) in the treatment groups decreased (P < 0.05). HMBi improved the concentrations of selenium in both TG1 (P < 0.05) and TG2 (P < 0.01). The levels of glutathion peroxidase (GSH‐Px) in TG2 were higher than those of the control group (P < 0.05). Moreover, HMBi increased the concentrations of growth hormone (GH) in both TG1 (P < 0.05) and TG2 (P < 0.01). These results indicate that the addition of HMBi increases growth performance, serum concentrations of GH and AST; 15 g/day HMBi increases concentrations of total protein and albumin, and 25 g/day HMBi increases concentrations of ALT and GSH‐Px.     

Effect of fast freezing then thaw‐aging on meat quality attributes of lamb M. longissimus lumborum

The objective of this study was to determine the effect of two different freezing rate then thaw‐aging regimens on the quality attributes of lamb loins. The loins were randomly allocated to one of five different freezing/thawing/aging regimes: fast‐(FF1A0) and slow‐(SF1A0) frozen only; fast‐(FF1A2) and slow‐(SF1A2) frozen then thaw‐aged for 14 days; aged for 14 days never frozen (A2). FF1A2 samples had a significantly higher water‐holding capacity compared to the slow frozen regardless of further aging periods. FF1A2 samples had lower (p < 0.05) shear force values than A2 and higher (p < 0.05) water‐holding capacity compared to the SF1A2. Fast freezing resulted in more intracellular cryo‐damage, whereas slow freezing resulted in extracellular cryo‐damage. FF1A0 and SF1A0 samples had lower (p < 0.05) myofibrillar proteins degradation. This study demonstrated that fast freezing then thaw‐aging can result in an improved water‐holding capacity and tenderness through the minimization of extracellular ice crystal formation, reduction in purge and drip losses, and improved proteolysis in thawed lamb.     

Effects of nutritional level of concentrate‐based diets on meat quality and expression levels of genes related to meat quality in Hainan black goats

The present study investigated the effects of the nutritional levels of diets on meat quality and related gene expression in Hainan black goat. Twenty‐four goats were divided into six dietary treatments and were fed a concentrate‐based diet with two levels of crude protein (CP) (15% or 17%) and three levels of digestive energy (DE) (11.72, 12.55 or 13.39 MJ/kg DM) for 90 days. Goats fed the concentrate‐based diet with 17% CP had significantly (P < 0.05) higher average daily gains (ADG) and better feed conversion rates (FCR). The pH _24h value tended to decrease (P < 0.05) with increasing DE levels. The tenderness of Longissimus dorsi muscle (LD) and Semimembranosus muscle (SM) reduced with increasing CP levels (P < 0.05). With increasing DE levels, tenderness was increased (P < 0.05). The heart fatty acid‐binding protein (H‐FABP) mRNA expression levels in LD and SM increased with increasing DE levels (P < 0.05), but decreased with increasing CP levels (P < 0.05). The calpastatin (CAST) and μ‐calpain mRNA expressions levels in LD and SM were affected significantly (P < 0.05) by CP and DE levels in the diet. Therefore, the nutritional levels of diets affect meat quality and expression levels of genes associated with meat quality in Hainan black goats.     

Calming effect of orally administered γ‐aminobutyric acid in Shih Tzu dogs

The calming effects of γ‐aminobutyric acid (GABA) by oral administration were investigated in four adult Shih Tzu dogs. Three dosage levels (1, 2 and 4 mg/kg body weight) and non‐administration were tested by an increase and decrease method. Changes in activity (for 1.5 h) and urinary cortisol levels (pre‐administration, 3 and 7 h later) of dogs were monitored after administration. Without reference to dosage level, the mean times spent standing (P = 0.06), sitting (P < 0.05) and walking (P < 0.05) tended to decrease compared to non‐administration. A significant depression in the urinary cortisol level was observed at 7 h after administration (P < 0.05). These results indicate that orally administrated GABA exerts calming effects on dogs as well as humans.     

An assessment of reproductive and lifetime performances of Kagoshima Berkshire gilts and sows

We investigated the reproductive and lifetime performances of Kagoshima Berkshire gilts and sows. We examined 20 605 parity records of 4419 pigs for 2008 to 2012 on a farrow‐to‐finish commercial farm. The mean parity (± SD) of all animals was 3.0 ± 2.1. For farrowing performance, the highest numbers of total pigs born and pigs born alive were found in sows with parities 5 and 6 and with parity 3–6, respectively (P < 0.05). Regarding weaning and mating performance, sows with parity 2 had the lowest preweaning mortality (P < 0.05). The longest weaning‐to‐first‐mating interval was found in parity 1 pigs, and the interval decreased as parity increased (P < 0.05). Parities 0 and 1 pigs had the lowest farrowing rate and those with parity 4 had the highest farrowing rate (P < 0.05). The mean parity at culling, total number of pigs born alive in a lifetime, and nonproductive days in a lifetime were 5.5 ± 2.93, 49.2 ± 24.72 pigs, and 132.1 ± 83.34 days, respectively. These animals had a lower litter size and fertility that the F₁ crossbred sows mainly used in Japan, but a similar tendency for performance by parity.     

Study on differentiation during embryonic development across selective and ancestral breeds

In order to explore the effect of strain on diverging post‐hatch muscle properties, muscle regulation during embryo development was investigated in selected and unselected breeds. Four broiler strains were used: JingNing (JN) chicken (a Chinese native chicken), HuangYu (HY) broiler, BaiYu (BY) broiler and Hyline layer (commercial crossbred chickens). Results showed that the four breeds had almost the same characteristic during different incubation periods. BY broilers moved more than JN and Hyline layers from Hamburger & Hamilton stage (HH)24 to HH31 (P < 0.05). HY broilers moved more than JN and Hyline layers from HH27 to HH31 (P < 0.01). All the embryos were heavier daily from HH24 to ED18 (P < 0.05); broilers presented greater body weights than JN and hyline layers (P > 0.05); broilers presented smaller fiber diameter than JN chickens before HH31 (P > 0.05). From then on, JN chicken exhibited smaller fiber diameter compared to the broilers (P > 0.05). Western blotting indicated all the breeds had continuous insulin‐like growth factor‐I (IGF‐I) expression, with the highest expression level in broilers from HH19 to HH24 and highest expression level in JN chicks from HH27 to HH31. The results indicated that the diverging growth among breeds was already shown in embryonic stages; the different expression patterns of IGF‐I may be involved in cell proliferation and differentiation.     

Early postmortem biochemical factors influence tenderness and water-holding capacity of three porcine muscles

The objective of this study was to determine whether differences in pork tenderness and water-holding capacity could be explained by factors influencing calpain activity and proteolysis. Halothane-negative (HAL-1843 normal) Duroc pigs (n = 16) were slaughtered, and temperature and pH of the longissimus dorsi (LD), semimembranosus (SM), and psoas major (PM) were measured at 30 and 45 min and 1, 6, 12, and 24 h postmortem. Calpastatin activity; mu-calpain activity; and autolysis and proteolysis of titin, nebulin, desmin, and troponin-T were determined on muscle samples from the LD, SM, and PM at early times postmortem. Myofibrils from each muscle were purified to assess myofibril-bound (mu-calpain. Percentage drip loss was determined, and Warner-Bratzler shear (WBS) force was analyzed. Myosin heavy-chain (MHC) isoforms were examined using SDS-PAGE. The pH of PM was lower (P < 0.01) than the pH of LD and SM at 30 and 45 min and 1 h postmortem. The PM had a higher (P < 0.01) percentage of the MHC type IIa/IIx isoforms than the LD. The-LD had the greatest proportion of (P < 0.01) MHC IIb isoforms of any of the muscles. The PM had the lowest (P < 0.01) percentage of MHC IIb isoforms and a greater (P < 0.05) percentage of type I MHC isoforms than the LD and SM. The PM had less (P < 0.01) drip loss after 96 h of storage than the SM and LD. The PM had more desmin degradation (P < 0.01) than the LD and SM at 45 min and 6 h postmortem. Degradation of titin occurred earlier in the PM than the LD and SM. At 45 min postmortem, the PM consistently had some autolysis of mu-calpain, whereas the LD and SM did not. At 6 h postmortem, some autolysis of mu-calpain (80-kDa subunit) was observed in all three muscles. The rapid pH decline and increased rate of autolysis in the PM paralleled an earlier appearance of myofibril-bound mu-calpain. The SM had higher calpastatin activity (P < 0.05) at 45 min, 6 h, and 24 h and had higher WBS values at 48 h (P < 0.01) and 120 h (P < 0.05) postmortem than the LD. At 48 and 120 h postmortem, more degradation of desmin, titin, and nebulin were observed in the LD than in the SM. These results show that mu-calpain activity, mu-calpain autolysis, and protein degradation are associated with differences in pork tenderness and water-holding capacity observed in different muscles.