Influence of transport conditions and pre‐slaughter water shower spray during summer on protein characteristics and water distribution of broiler breast meat

This study investigated the effects of pre‐slaughter transport during summer and subsequent water shower spray on broiler meat quality and protein characteristics. Arbor Acres broiler chickens (n = 126, 42 days old, mixed sex, 2.5‐3 kg) were randomly categorized into three treatments: (i) control group without transport (C); (ii) 30 min transport (T); and (iii) 30 min transport followed by 10 min water shower spray and 20 min lairage (T/W). Each treatment consisted of six replicates with seven birds each. Ambient temperature was 32‐35°C during transportation. Results indicated that transport during high ambient temperature denatured myosin and sarcoplasmic proteins, led to decreased protein solubility and resulted in glycogen phosphorylase precipitated to the myofibrillar fraction. Furthermore, meat quality in the transport group showed a pale, soft and exudative (PSE)‐like syndrome. Water shower spray during lairage after transport reduced the degree of protein denaturation and lessened the deterioration of meat quality.     

Effect of animal age,postmortem chilling rate,and aging time on meat quality attributes of water buffalo and humped cattle bulls

The study was aimed to investigate the influence of animal age, post‐slaughter chilling rate, and aging time on meat quality of M. longissimus dorsi (LD) of water buffalo (Bubalus bubalis) and humped cattle (Bos taurus indicus) bulls. After slaughtering, one side of carcasses was subjected to rapid chilling (RC) (0 ± 2°C) and other side was hanged in controlled room temperature (25 ± 2°C) for 3 hr, then allowed to the chiller (0 ± 2°C). The meat quality traits were analyzed at 1, 7, and 14 days of storage. It was noted that rapidly chilled carcasses from the younger animals of both species missed the ideal pH/temperature window, which affects the toughness of the meat. Buffalo meat presented higher shear force, color L* values, and lower b* value as compared to the cattle meat. Moreover, meat shear force values decreased while all color coordinates and cooking loss values increased with lengthening the storage time in both age groups of cattle and buffalo. In conclusion, the tenderness of cattle meat was superior to that of buffalo and RC adversely affect the shear force values of young cattle and both age groups of buffalo bulls.     

Dose response of rumen‐protected conjugated linoleic acid supplementation to fattening bulls and heifers on growth,and carcass and meat quality

We investigated the influence of rumen‐protected conjugated linoleic acid (rpCLA) on growth performances, and carcass and meat quality traits in beef. Twenty‐four young bulls and 30 heifers obtained from double‐muscled beef sires and dairy cows were fed a low‐protein ration (110 g/kg DM of crude protein) supplemented with 0, 8 or 80 g/d of a commercial rpCLA product. The animals were monthly weighed and scored for body muscularity and fatness. Blood samples were collected after 140 days on feed. Animals were slaughtered when they reached average in vivo fatness scores of around 2.5 (heifers) and 2.0 (bulls) points respectively. At slaughter, carcasses, various organs and parts of the gastrointestinal tract were weighed; the 5th rib was dissected and its tissue and muscle chemical composition was determined. The rpCLA had little influence on growth performance but decreased the blood urea content by 28% (p < 0.01). The rpCLA × sex interactions for daily gain (p < 0.05), conformation scores (p < 0.01), and blood creatinine content (p < 0.05) suggest that males were more responsive to rpCLA than females when fed a low‐protein ration, probably because of the metabolic protein‐sparing effect of CLA. Only slight differences were observed in carcass weight and quality at slaughter. The results indicate that the response of beef cattle to rpCLA is dependent on sex or on their propensity for lean and fat accretion. It is also possible that counteracting feedback mechanisms compensate for the influence of rpCLA administration over the course of growth.     

Effect of lairage time,behaviour and gender on stress and meat quality parameters in pigs

The objective of this study was to determine the effects of lairage time (short vs. long), behavior (aggressive vs. non‐aggressive) and gender (gilts, barrows and boars) on stress and meat quality parameters in pigs (n = 100). In the group with short lairage, aggressive behavior of gilts and boars was observed. At exsanguination, blood samples were collected and levels of blood lactate and plasma cortisol were determined. Post mortem pH value, temperature, drip loss, sensory and instrumental color and meat quality class were determined on the muscle Longissimus dorsi. Higher blood lactate concentration (P < 0.05) and skin blemish score (P <0.001), lower temperature (P < 0.05) and drip loss (P < 0.01), as well as darker, less red and yellow meat color (P < 0.001) were found after long lairage compared to short lairage. Gilts had higher plasma cortisol concentrations than barrows (P < 0.05), while barrows had lower skin blemish scores (P < 0.05) than gilts and boars after long lairage. The highest incidence of PSE (pale, soft and exudative) meat was observed in barrows (100.00%) and boars (91.67%) after short lairage, while the lowest incidence of PSE meat was found in barrows (28.89%) after long lairage. Aggressiveness affected meat temperature, as aggressive pigs had higher meat temperature (P < 0.05) than non‐aggressive pigs.     

Effect of dietary methionine on growth performance and insulin‐like growth factor‐I mRNA expression of growing meat rabbits

An experiment was conducted to determine the effects of different amounts of dietary methionine on growth performance, serum protein, growth hormone (GH), insulin‐like growth factor‐I (IGF‐I) concentrations and IGF‐I mRNA expression of growing meat rabbits. One hundred weaned growing meat rabbits were allocated to individual cages and randomly divided into five groups. The methionine addition concentrations of the five groups were 0, 2, 4, 6 and 8 g/kg diet (as‐fed basis) and sulphur amino acids (SAA) concentrations ranging from 3.8 to 11.6 g/kg diet, respectively. The results obtained were as follows: the average daily gain of 2, 4 and 6 g/kg diet groups was higher than that of 0 g/kg diet group (p < 0.01). The feed gain ratio of the 4 g/kg diet group was lower than those of 0 and 8 g/kg diet group (p < 0.01). Methionine concentrations did not affect serum urea nitrogen, total protein, insulin and IGF‐I concentration (p > 0.05). The quadratic effects of methionine on the serum concentration of albumin (Alb) and GH were obtained (p = 0.013, p = 0.018). The quadratic effect of methionine amount on IGF‐I mRNA expression was obtained (p = 0.045). The serum concentration of Alb of the 4 g/kg diet group was higher than those of 0 and 8 g/kg diet group (p < 0.01). The serum concentration of GH of 8 g/kg diet group was higher than that of the 0 g/kg diet group (p < 0.05). The liver IGF‐I mRNA expression of 4 g/kg diet group was higher than those of the 0 and 8 g/kg diet group (p < 0.05). Providing a diet mainly consisted of corn, wheat bran and peanut vine, the optimum dietary methionine addition concentration and SAA concentration for a weaner to 2‐month‐old growing meat rabbits were shown to be 2 and 5.7 g/kg diet respectively.     

Evaluation of T2‐weighted versus short‐tau inversion recovery sagittal sequences in the identification and localization of canine intervertebral disc extrusion with low‐field magnetic resonance imaging

Sagittal T2‐weighted sequences (T2‐SAG) are the foundation of spinal protocols when screening for the presence of intervertebral disc extrusion. We often utilize sagittal short‐tau inversion recovery sequences (STIR‐SAG) as an adjunctive screening series, and experience suggests that this combined approach provides superior detection rates. We hypothesized that STIR‐SAG would provide higher sensitivity than T2‐SAG in the identification and localization of intervertebral disc extrusion. We further hypothesized that the parallel evaluation of paired T2‐SAG and STIR‐SAG series would provide a higher sensitivity than could be achieved with either independent sagittal series when viewed in isolation. This retrospective diagnostic accuracy study blindly reviewed T2‐SAG and STIR‐SAG sequences from dogs (n = 110) with surgically confirmed intervertebral disc extrusion. A consensus between two radiologists found no significant difference in sensitivity between T2‐SAG and STIR‐SAG during the identification of intervertebral disc extrusion (T2‐SAG: 92.7%, STIR‐SAG: 94.5%, P = 0.752). Nevertheless, STIR‐SAG accurately identified intervertebral disc extrusion in 66.7% of cases where the evaluation of T2‐SAG in isolation had provided a false negative diagnosis. Additionally, one radiologist found that the parallel evaluation of paired T2‐SAG and STIR‐SAG series provided a significantly higher sensitivity than T2‐SAG in isolation, during the identification of intervertebral disc extrusion (T2‐SAG: 78.2%, paired T2‐SAG, and STIR‐SAG: 90.9%, P = 0.017). A similar nonsignificant trend was observed when the consensus of both radiologists was taken into consideration (T2‐SAG: 92.7%, paired T2‐SAG, and STIR‐SAG = 97.3%, P = 0.392). We therefore conclude that STIR‐SAG is capable of identifying intervertebral disc extrusion that is inconspicuous in T2‐SAG, and that STIR‐SAG should be considered a useful adjunctive sequence during preliminary sagittal screening for intervertebral disc extrusion in low‐field magnetic resonance.     

Effect of L‐theanine on meat quality,muscle amino acid profiles,and antioxidant status of broilers

This study investigated the effect of L ‐theanine on carcass traits, meat quality, muscle antioxidant capacity, and amino acid (AA) profiles of broilers. Three hundred 1‐day‐old Ross 308 male broilers were randomly allotted to five groups with six replicates. Birds were fed the basal diet or basal diet with 300, 600, 900, or 1,500 mg/kg L ‐theanine for 42 consecutive days. The results showed that L ‐theanine quadratically increased dressing percentage, eviscerated percentage, and leg muscle yield (p < .05). Meanwhile, drip loss, cooking loss, shear force, L*_24h, and muscle lactate content decreased quadratically in response to dietary L ‐theanine supplementation (p < .05), while pH_24h and muscle glycogen content were quadratically improved by L ‐theanine (p < .05). Notably, the contents of muscle malondialdehyde and protein carbonyl, and the activities of muscle total antioxidant capacity, catalase, and glutathione peroxidase decreased quadratically in response to dietary L ‐theanine supplementation (p < .05), suggesting that the oxidative stress level of muscle was decreased quadratically. Moreover, L ‐theanine quadratically increased the concentrations of most of muscle essential AA, nonessential AA, and flavor AA (p < .05). In conclusion, L ‐theanine can be used as a valuable feed additive to modulate carcass traits, meat quality, muscle antioxidant status, and AA profiles of boilers, and its optimum addition level is 600 mg/kg based on the present study.     

Effect of posttransportation grazing on the physiological condition and meat quality traits of Black Bengal goats

This study was designed to reveal the role of posttransportation grazing on the physiological condition and meat quality traits of Black Bengal goats. Twenty‐four castrated male Black Bengal goats were divided into a control (untransported) group and three treated groups: Walking and Transportation with Human Interference group (WTHI) (30 min walking before 6 hr transport and then 30 min walking with human interference), posttransportation grazing for 48 hr (PTG1), and posttransportation grazing for 72 hr (PTG2). The WTHI and PTG1 groups had a significant reduction in their blood concentrations of tri‐iodothyronine (T₃) and thyroxine (T₄), and a significantly higher neutrophil and lymphocyte (N:L) ratio compared with those of the control group. Blood concentrations of T₃ and T₄ and the N:L ratio of PTG2 returned to the control level after 72 hr of grazing. The final pH and water‐holding capacity values of meat were significantly higher in the WTHI group than in the control group, but those in the PTG2 group returned to the control level after 72 hr of grazing. These results demonstrate that posttransportation grazing for 72 hr is effective for recovering from damage induced by transportation stress.     

庄河大骨鸡GHR、IGF-Ⅰ基因的多态性及基因聚合对产肉性能的影响

本文旨在探究庄河大骨鸡GHR和IGF-Ⅰ基因产肉性能的遗传标记及聚合基因型的效应,为庄河大骨鸡的选育奠定理论基础。利用PCR-RFLP标记技术和最小二乘法分析了GHR、IGF-Ⅰ单基因型和聚合基因型与17周龄产肉性能的关联。结果发现:GHR基因和IGF-Ⅰ基因都存在3种基因型且处在哈代温伯格平衡状态;GHR基因AA型的活体重、屠体重、半净膛重、全净膛重、胸肌重和平均日增重分别显著高于AB型和BB型(P<0.05);IGF-Ⅰ基因DD型的活体重、屠体重、半净膛重、全净膛重、腿肌重和平均日增重分别显著高于CC型和CD型(P<0.05);聚合基因型AADD、AACD和ABDD的活重、屠体重、半净膛重、全净膛重、胸肌重、平均日增重显著高于其他各基因型(P<0.05)。GHR基因的AA型,IGF-Ⅰ基因的DD型和聚合基因型AADD、AACD、ABDD对鸡的产肉性能有显著影响,但是能否作为庄河大骨鸡选育的理论依据还需进一步研究。     

Effect of fructo‐oligosaccharides on nutrient digestibility and digesta retention time in adult guinea pigs

A previous study suggested that addition of fructo‐oligosaccharides (FOS) to the diet improved nitrogen (N) utilization and decreased acid detergent fiber (ADF) digestibility in guinea pigs. The present study was conducted to clarify the relationship between ADF digestibility and gastrointestinal mean retention time (MRT) in guinea pigs under FOS supplementation. Adult male guinea pigs were fed a commercial diet (50 g/day) with either 5% glucose (glucose group) or 5% FOS (FOS group) for 12 days in individual metabolism cages. Unlike the glucose group, N utilization improved, but ADF digestibility significantly (P < 0.05) decreased in the FOS group. MRT of solid digesta also significantly (P < 0.05) decreased in the FOS group compared with that in the glucose group. We concluded that reduction of MRT of solid digesta containing FOS decreased ADF digestibility in guinea pigs.     

Effect of time at pasture and herbage intake on profile of volatile organic compounds of dairy cow milk

Volatile organic compounds (VOCs) in milk were investigated as quantitative markers of herbage intake (HI) at pasture. Eight Holstein cows were fed indoors with concentrate and conserved forages (grass silage, corn silage and hay) (NG), then were divided into three treatments according to the duration of access to pasture: 4 h (G4), 8 h (G8), and 20 h (G20) per day. The HIs were 4.3, 8.6, and 13.0 kg dry matter/day for the G4, G8 and G20 treatments, respectively. Milk from cows was sampled and analyzed VOCs by the steam distillation‐extraction method and gas chromatography‐mass spectrometry (GC‐MS). From the intensity of the GC peak area, the levels of 1‐phytene (3,7,11,15‐tetramethyl‐1‐hexadecene) and 2‐phytene (3,7,11,15‐tetramethyl‐2‐hexadecene) were lowest in NG treatment and markedly increased with grazing time at pasture. With simple regression analysis on the HI to each diterpenoid, a strong correlation was found between the intensity of 1‐phytene in the milk and the HI (r = 0.807, P < 0.001). 1‐phytene content in milk could be useful as a quantitative marker of the HI of grazing cows.     

Effect of D‐mannitol on nitrogen retention,fiber digestibility and digesta transit time in adult rabbits

The aim of the current study was to elucidate the effect of gastrointestinal retention time of digesta on fiber digestibility in adult rabbits fed indigestible, but fermentable, sugar D‐mannitol. Six adult rabbits were fed alternately a commercial diet containing 5% glucose and a diet containing D‐mannitol. Total feces and urine were collected during the experimental period. Nitrogen (N) balance, digestibility of nutrients, and gastrointestinal mean retention time (MRT) were measured. The results indicated that urinary excretion was significantly lowered, whereas N retention and N accumulation rates were significantly increased in the D‐mannitol group compared with the glucose group (P < 0.05). However, fecal N excretion was unaffected. Absorption of crude ash (CA) and acid detergent fiber (ADF) digestibility were significantly higher in the D‐mannitol group compared with the glucose group (P < 0.05). The addition of D‐mannitol to the diet did not affect the MRT of liquid digesta, but increased the MRT of solid digesta compared with the glucose group (P < 0.05). These results suggest that the addition of D‐mannitol to the diet stimulates cecal bacterial growth, thereby increasing N utilization and digesta retention time.     

Effect of water‐soluble carbohydrate content in orchardgrass pasture on grazing time and rumen fermentation in dairy cows

Two experiments were conducted to clarify the effect of water‐soluble carbohydrate (WSC) content in orchardgrass pasture on the diurnal distribution of grazing time. Six ruminally cannulated, non‐lactating dairy cows were grazed on either of two pastures with different orchardgrass cultivars containing low WSC (LWSC; cultivar: ‘Hokkai 28’) or high WSC (HWSC; cultivar: ‘Harunemidori’). The cows were grazed in morning and evening sessions in experiment 1, whereas the cows were grazed throughout the day in experiment 2. In experiment 1, grazing time of the cows on HWSC was longer than that of the cows on LWSC (P < 0.01). This difference was larger in the morning session than in the evening session (pasture × grazing session: P < 0.05). Effects on herbage intake were similar to those on grazing time. In experiment 2, daily total grazing time was longer for the cows on HWSC than for those on LWSC (P < 0.05). The cows on HWSC spent a longer time grazing than those on LWSC in the morning between 03.00 and 09.00 hours (P < 0.01). The results indicated that prolonged grazing time in the period between dawn and early morning could increase daily herbage intake in cows grazed on pastures of orchardgrass cultivars with high‐WSC content.     

Effects of calcium soap of rice bran oil fatty acids supplementation alone and with DL‐α‐tocopherol acetate in lamb diets on performance,digestibility, ruminal parameters and meat quality

Thirty‐six Malpura lambs (28 day old and 6.7 ± 0.25 kg BW) were distributed equally in three groups having six males and six female. They were ad libitum fed individually three different experimental diets containing calcium soap of fatty acids (CA‐FA) at 0 (T₁) and 40 (T₂ and T₃) g/kg concentrate up to six months of age. Animals in T₃ were supplemented additionally with 40 mg DL‐α‐tocopherol acetate/kg of concentrate. The roughage moiety included ad libitum dry Prosopis cineraria and fresh Azadirachata indica leaves. All the lambs were allowed to suckle from their dam up to weaning (90 day of age). Supplementation of Ca‐FA improved weight gain and feed conversion ratio during both pre‐ (28–90 days) and post‐weaning (91–180 days) phases; however, no effect of DL‐α‐tocopherol was observed. Metabolic parameters during post‐weaning phase revealed non‐significant effect on digestibility but improved nitrogen balance in the test groups. The effect on biochemical attributes did not show any significant alteration in ruminal parameters, blood biochemicals and urinary purine derivatives. Carcass traits revealed higher (p < 0.05) dressing yield and loin eye area with Ca‐FA supplementation. The value of thiobarbituric reactive substances for nuggets prepared from frozen carcasses revealed significant (p < 0.05) reduction in T₃ compared to the other dietary groups. Fatty acid profile of adipose tissue revealed higher (p < 0.001) 9‐octadecanoic, 9‐12‐octadecadienoic, polyunsaturated fatty acids (PUFA), higher ratio of PUFA/saturated fatty acids (SFA), ω‐6/ω‐3 and lower SFA in Ca‐FA‐supplemented groups. It is concluded that supplementation of 40 g/kg calcium soap prepared from industrial grade rice bran oil in lamb ration provided additional energy intake, improved N utilization, gain and feed conversion ratio besides improving dressing yield and meat quality with CLA enriched fatty acid profile. DL‐α‐tocopherol acetate when supplemented at 40 mg/kg feed reduced lipid oxidation of meat products thus improving its keeping quality.