This study was conducted to investigate the effect of dietary total mixed ration (TMR) supplementation and dry-aging period on the physico-chemical and sensory quality of striploin (longissimus lumborum) from multiparous Hanwoo cows. The experimental cows were divided into two treatments (n=3/treatment) according to the type of feed: in one treatment (slaughter age: 87±6 months old, parity: 5±1) the cows were fed on TMR for 7 months before slaughter, while in the other treatment (slaughter age: 83±9 months old, parity: 5±2) the cows were fed on concentrate and rice straw (CRS) for the whole rearing period. After slaughtering, the striploins were dry-aged for 20 or 40 days at 2±1℃, 85% relative humidity and 2 m/sec air flow velocity and then utilized for quality measurements. The pH value, cooking loss, and hypoxanthine content were higher (p<0.05) for the striploins dry-aged for 40 days than for those dry-aged for 20 days. Notably, the inosine 5’-monophosphate content was decreased (p<0.05) by increasing the dry-aging time. With regard to microbiological quality, the striploins dry-aged for 40 days exhibited lower (p<0.05) lactic acid bacteria counts and higher (p<0.05) coliform counts than those dry-aged for 20 days. Moreover, the tenderness and overall liking scores based on sensory evaluation were higher (p<0.05) for the dry-aged striploins of the TMR treatment and those dry-aged for 40 days than for the CRS treatment and those dry-aged 20 days, respectively. These findings suggest that dietary TMR supplementation leads to an increase in the sensory preference of dry-aged striploins from multiparous Hanwoo cows, and alteration of the CRS into the TMR may improve the quality of dry-aged Hanwoo beef.
This study aimed to investigate the effects of probiotic treatment with IgY and Bacillus subtilis complex on diarrhea and weight gain in Hanwoo calves. Bacillus and E. coli levels were measured in the feces of calves post probiotic administration. Subsequently, calves with diarrhea were divided into two groups. The total and daily weight gain was measured in 23 calves after three months of suckling and divided into three groups. In Test 1, Bacillus was detected of the control group constantly at 104 CFU/g; a statistically significant difference was observed between the treatment and the control groups on the 1st and 3rd day (p<0.05) but not on the 7th day, confirming that the Bacillus subtilis survived in the intestine only until the 7th day. The treatment and control groups in Test 2 did not show any significant difference in the E. coli levels. However, comparison of changes in the E. coli levels showed a decreased of 6.39×108±9.80×108 CFU/g in the control group increase by 1.54×109±2.16×109 CFU/g, and, a decrease by 1.47×109±2.20×109 CFU/g; a decrease of by 4.20×107±3.90×108 CFU/g was observed in the treated group, an increase by 7.19×108±2.04×109 CFU/g, anda a decrease by 9.22×108±1.79×109 CFU/g. The changes in, control group were more rapid than in the treatment group. Therefore we hypothesize that probiotics inhibit E. coli growth. A concurrent improvement in weight gain was observed following probiotic administration. The IgY and Bacillus subtilis probiotics complex used in this study can be effectively used for the prevention and treatment of calf diarrhea.
The present study was conducted to investigate the effect of environmental temperature and backfat thickness (BT) on the reproductive performance of lactating sows. Sixty crossbred sows were allotted to four groups in a 2×2 factorial arrangement by environmental temperature (high temperature [HT], 27.5±1.76℃; low temperature [LT], 23.3±0.89℃) and BT (<20 mm, average 17.70 mm; ≥20 mm, average 23.20 mm) from July to August 2019. Sows in the HT group experienced a greater change in BT and a lower feed intake. Losses in body weight and BT were lower in sows with <20 mm BT than in those with ≥20 mm BT. Sows with low BT had a lower weaning-to-estrus interval than sows with high BT (5.20, 4.93 d vs. 5.87, 5.60 d, respectively). Piglet survivability was lower in the HT group (90.31%) than in the LT group (94.87%). Piglet weaning weight and average daily weight gain were greater in sows with <20 mm BT (5.75 kg and 201.46 g, respectively) than in those with ≥20 mm BT (5.49 kg and 188.41 g, respectively). Sows in the HT group had higher cortisol concentrations than those in the LT group (post-farrowing: HT 7.86 μg/mL vs. LT 6.04 μg/mL; weanling: HT 5.48 μg/mL vs. LT 4.40 μg/mL). In conclusion, environmental temperature adversely influenced sow performance and cortisol levels. Moreover, sows with low BT had a greater weaning-to-estrus interval when subjected to heat stress.
This study investigated the effects of π-ray treated feeds on the growth performance, carcass composition, internal organ weight, and sensory evaluation of broilers. One hundred and eighty broiler chicks were used as experimental animals. These were divided into four treatment groups according to the π-ray treated feed supplement level: 0% (control) 1%, 3%, and 5%. The π-ray treated feeds did not significantly affect on the body weight gain (2,484–2,602 g), feed intake (4,747–4,944 g), and feed efficiency (1.90–1.98) in broilers (p>0.05). Also, carcass protein (20.2–20.4%) and fat (4.6–4.9%) contents were not affected. The lengths (178.0, 182.7, 198.0, and 190.3 cm) and weights (38.4, 41.2, 44.2, and 38.9 g/kg of body weight) of the small intestine were slightly but not significantly higher in the π-ray treatments than in the control. Further, there were no overall effect of the π-ray treatment on the abdominal fat pad (2.3, 2.1, 2.1, and 1.8%), and cecum (6.7, 4.0, 5.6, and 6.0 g/kg of body weight) and gizzard (16.8, 15.2, 18.0, and 16.6 g/kg of body weight) weights of the broilers in the present study (p>0.05). The stickiness (2.25, 4.25, 4.50, and 4.38) and flavor (2.44, 4.25, 4.31, and 4.38) of cooked breast meat were higher in the π-ray treatments than in the control (p<0.01). This study also found that, in humans, eating cooked breast meat of broilers that were fed π-ray treated feeds had a positive effect on the blood circulation in the capillaries. Thus, the findings of this study suggest that dietary π-ray treatment has a positive effect on the sensory evaluation of broilers, without any negative effect on their body weight gain, feed intake, and feed efficiency, and that the consumption of these broilers is beneficial for humans on their blood circulation.
The senior dog population (ages 7+) is increasing worldwide because of a larger interest in the health of companion dogs. In this study, we aimed to develop dog foods via fermentation to address the nutritional needs of senior dogs. The dog food ingredients were fermented with candidates of starter culture and then the fermentation efficiency was compared using pH and ammonia nitrogen for selection of optimum strains. The fermentation was carried out with a moisture content of 60% and starter culture of 1.0×107 cfu/g at 3 7℃ for 24 h. And there were manufactured pre- and post-senior dog foods (treatments) including fermented rice, fermented pinto bean, and fermented soybean meal and it compared with non-fermented dog foods (controls) on fermentation characteristics, in vitro dry matter and crude protein digestibility, and palatability. As results of this study, fermentation efficiency was higher when rice or wheat was inoculated with Lactobacillus brevis (ΔpH; -2.74 ~ -2.94) and meat and bone meal with Lactobacillus reuteri (ΔNH3-N conc.; 4.29 g/L). The ammonia nitrogen level, total volatile fatty acid content, in vitro dry matter and crude protein digestibility of L. brevis-fermented dog food were significantly greater than those of non-fermented dog food (p<0.05). Further, in case of palatability tests, fermented foods tended to have higher palatability compared to non-fermented foods, and no negative effect was observed in fermented foods. These results suggest that fermented food is suitable for senior dogs and could help to maintain adult dog health.
The fatty acid binding protein 4 (FABP4) gene plays an important role in lipid metabolism and homeostasis in adipocytes. The objective of this study was to analyze the association between a single nucleotide polymorphism (SNP), g.7516G>C, in the FABP4 gene and economic traits of Korean native cattle, Hanwoo. Primers were designed to target a region of the FABP4 gene between nucleotides 7417 and 7868 (AAFC01136716). The SNP, which was detected by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) method using restriction enzyme MspA1I, was genotyped in 319 animals of Hanwoo steer population. Statistical analysis showed that the SNP genotype of the FABP4 gene significantly affected carcass weight (CW, p<0.01), longissimus muscle area (LMA, p<0.001), and marbling score (MS, p<0.001). GG allele of the SNP on 246 animals in a Wagyu × Limousin F2 reference population showed a higher MS (p<0.05) and subcutaneous fat depth (p<0.05) in previous report. But CC allele of the SNP showed greater values for MS, LMA, and CW in Hanwoo steers. These results suggest that the g.7516G>C SNP located in the FABP4 gene may affected differently depending on the cattle breed and can be used as a genetic selection marker in Korean native cattle.
The creation of probiotic-containing fermented milk products for use by human is an important research topic and has high potential for development. Also, studies have shown that heat-killed probiotics are more stable and easier to use than live probiotics. However, as of this time, research has not been reported in Korea that has evaluated the product or functionality of fermented milk after the addition of heat-killed probiotics. This study was conducted to verify the physiological activity of heat-killed Enterococcus faecalis EF-2001 after its addition to Lactobacillus-fermented milk. Briefly, NFM normal fermented milk (NFM) was used as the control sample, whereas fermented milk with 100 μg/mL EF-2001 (EFM1) and fermented milk with 500 μg/mL EF-2001 (EFM2) were used as the treated samples. Among the samples, EFM2 had the highest acidity of 1.15, but no other factors significantly differed (p<0.05). Furthermore, EFM2 had the highest Lactobacillus count of 9.22 (p<0.05). ABTS, DPPH and FRAP were measured to determine the antioxidant activity of the samples. With respect to those parameters, EFM2 had the highest antioxidant measurements. Therefore, the study confirmed that the addition of E. faecalis EF-2001 to NFM is suitable with the standard and does not affect the quality of characteristics. In conclusion, the treatment sample had higher antioxidant activity than did NFM; this result may be used as a basic for further research and as a guideline for the manufacturing of heat-killed probiotic-containing NFM.
The objective of this study was to investigate the quality characteristics of emulsion-type pork sausage manufactured with various levels of Eutrema Japonicum (E. Japonicum)(1, 2, and 3%). The crude fat contents of samples containing 2 and 3% E. Japonicum were 27.46-28.38%, significantly higher than those in the control (p<0.05). The cooking yields samples containing 1 and 2% E. Japonicum were 74.99-75.54%, significantly higher than those in the control (p<0.05). Water holding capacities (WHC) of the samples containing 1% and 2% E. Japonicum were 92.22-92.26% significantly higher than those in the control (p<0.05). while the water losses of sample containing 1% E. Japonicum group was 16.41%, significantly lower than those in the control (p<0.05). And fat losses samples containing 1, 2, and 3% E. Japonicum were 0.03-0.64% significantly lower than those in the control (p<0.05) in emulsion stability. Additionally, viscosity increased with increasing E. Japonicum concentration of E. Japonicum. Texture profile analysis (TPA) showed increased with increasing E. Japonicum concentration for hardness, springiness, cohesiveness, gumminess, chewiness. Thiobarbituric acid reactive substances (TBARS) in the samples containing 2 and 3% E. Japonicum were 0.64-0.69 mg MDA/kg significantly lower than those in the control and 1% E. Japonicum group (p<0.05). These results indicate that emulsion-type pork sausage containing 2% E. Japonicum was increasing WHC, emulsion stability, cooking yield, and was decreasing TBARS compared to other E. Japonicum groups. Therefore, emulsion-type pork sausage containing 2% E. Japonicum is high qualified.
In in vitro fermentation studies, feed samples can either be included in the in vitro rumen medium using filter bags or can be directly dispersed. The objective of this study was to investigate the effects of different pore sizes of filter bags on the rumen fermentation characteristics in an in vitro system. Corn, soybean meal, and timothy were ground to pass through a 1.0-mm screen and were formulated in the ratio of 70:7:23 based on DM, respectively. The formulated experimental diet (2g/DM) was put in F57 filter bags and R510 nylon bags (Ankom®) which pore sizes were 25 and 50 μm, respectively. An in vitro study was conducted to determine the rumen fermentation characteristics for 3, 6, 12, 24, and 48 h and rumen microbial community at 48 h of incubation. A significantly higher production of gas was observed in the R510 bags than in F57 at all the incubation times (p<0.01). IVDMD (p<0.01) and IVNDFD (p<0.01) were significantly higher, whereas pH (p<0.01) and NH3-N (p<0.01) were lower when R510 bags were used. In the VFA composition, acetate and butyrate were significantly higher (p<0.01) in R510 bags, and propionate and total VFA concentration did not differ (p=0.55 and 0.25, respectively) between F57 and R510 bags. The log copy numbers of bacteria and protozoa did not differ (p=0.69 and 0.94, respectively) between F57 and R510 bags, whereas those of fungi were significantly higher in R510 than in F57 bags (p<0.01). Therefore, the use of R510 may reflect actual rumen fermentation characteristics more precisely than those of F57 because increased gas production, nutrient digestibility and acetate, butyrate proportion were founded in R510.
The long-tailed goral (Naemorhedus caudatus) is an endangered animal species in all its habitats worldwide, including South Korea. The imbalanced sex ratio in fragmented habitats is closely associated with extinction. Therefore, sex identification using wild animal samples would be necessary. However, only a few studies have been reported about the sex identification of gorals. In this study, we thus aimed at comparing the efficiency of sex identification using various goral sample types as templates and the amelogenin (AMEL) and DEAD-box polypeptide 3 (DDX3) genes as target sequences. We extracted DNA from goral feces, tissues, and blood samples, then amplified the AMEL (SE47/SE48 and SE47/SE53 primer pairs) and DDX3 genes for sex identification, comparing the goral DDX3X and DDX3Y target sequences to those in cattle. Our results indicated that the tissue- and blood sample-derived AMEL amplicons showed an unspecific band pattern containing the sex-specific band in the case of both primer pairs we used, whereas the DDX3 amplicon showed only the sex-specific band. In the case of the feces samples, only the sex-specific band was amplified using both the AMEL and DDX3 primer pairs. However, we found that the DDX3 amplicon exhibited a clearer band pattern than the AMEL amplicon. Then, we compared the DDX3X and DDX3Y target sequences between cattle and gorals. We found 5 and 8 nucleotide differences in the DDX3X and DDX3Y sequences, respectively. In conclusion, the DDX3 gene-related sex identification of the long-tailed goral appears to be more efficient and precise than the AMEL gene-related approach. This method could be used for the sex identification of the members of the Bovidae family.
The experiment was undertaken to measure the potential impact of animal welfare on the pork quality under two different farming systems: C1 and C2, two conventional farms; W, an animal welfare farm. Ten pigs (Landrace × Yorkshire × Duroc) of live weight 110 kg were randomly selected from each treatment, and slaughtered under uniform conditions. The left loins were collected, and subsequently analyzed for proximate composition, meat quality traits, fatty acids, free amino acids, and antioxidative dipeptides. Pork from the welfare farm (W) had greater back-fat depth and fat content, but the values were not significantly different from C1 or C2. The W loins had significantly lower moisture contents and pH values compared to C1 or C2. The C2 loins showed highest contents of unsaturated fatty acids, whereas C1 had higher polyunsaturated fatty acids as compared to W. The treatments did not show any significant differences in the contents of free aspartic acid. Anserine (an antioxidant dipeptide) from the W loins was significantly lower than that from the conventional farms. The results indicate that pork quality characteristics from animal welfare-farmed pigs were not different from those of conventional farms. Therefore, it would be appropriate to evaluate the industrial value of animal welfare livestock only at the stage of pig production, rather than the meat quality of pork.
This study investigated the antioxidant properties of the Radix isatidis extract and the effect of substituting it with sodium nitrite (SN) in a pork patty. The antioxidant activity of the Radix isatidis water extract (RIWE) was compared to those of the methanol and chloroform extracts (RIME and RICE, respectively). Patties were prepared with five different treatments: (1) a control with no RIWE and SN, (2) T1 with 150 ppm SN, (3) T2 with 100 ppm SN + 0.1% RIWE, (4) T3 with 50 ppm SN + 0.3% RIWE, and (5) T4 with 0.5% RIWE. They were used to compare the oxidation stability for 12 days at 4℃. The extraction yield of RIWE was 3.2 and 18.7 times higher (p<0.05) than those of RIME and RICE, respectively, but RIWE had the lowest (p<0.05) 1,1`-diphenyl-2-picrylhydrazyl radical scavenging activity, superoxide dismutase-like activity, and total reducing ability. Patties with RIWE and SN exhibited lower (p<0.05) pH values after 12 days, compared to the control. After 4 days, the 2-thiobarbituric acid reactive substances content was lower (p<0.05) in T1, T2, T3, and T4 than in the control. The oxidation-reduction potential value was the lowest (p<0.05) in T3 and T4 after 4 days (p<0.05). T1, T2, T3, and T4 had a lower (p<0.05) volatile basic nitrogen content after 12 days, compared to the control. These findings suggest that RIWE has an antioxidant effect similar to that of SN, but further research on its antimicrobial effect may be required to determine if it is a good substitute for SN.
This study examined the quality characteristics of chicken breast emulsion-type sausages manufactured with different contents of Zanthoxylumschinifolium (Z.S.) powder (0, 1, 2 and 3%). The changes to the samples upon inclusion of Z.S. powder were monitored by measuring the proximate composition, pH, color, cooking yield, viscosity, texture profile analysis and protein solubility. The sausages manufactured with increasing amounts of Z.S. powder showed a decrease significantly in fat content (p<0.05), whereas the ash content increased. The pH of the cooked samples also decreased significantly with the increasing content of Z.S. powder (p<0.05). Before and after cooked lightness significantly decreased as the Z.S. powder content increased (p<0.05). The redness of the cooked samples also increased significantly with an increasing amount of Z.S. powder (p<0.05). Samples that contained 2% and 3% of Z.S. powder resulted in a significantly larger cooking yield compared to the control sample and the one containing 1% of Z.S. powder (p<0.05). The viscosity of the uncooked samples also increased with increasing amount of Z.S. powder. Furthermore, the samples containing 3% of Z.S. powder showed significantly lower levels of hardness and springiness than the control sample (p<0.05). In addition, the sample with 3% of Z.S. powder contained showed significantly higher total protein and myofibrillar protein levels than the other samples (p<0.05). Overall, the 3% of Z.S. powder chicken breast emulsion-type sausage performed well in most quality characteristic categories, and this formulation would be suitable for use in food manufacturing.
The objectives of this study were to estimate genetic parameters and breeding values of four carcass traits of the Hanwoo cattle breed: carcass weight (CWT), back fat thickness (BFT), eye-muscle area (EMA), and marbling score (MAR). Genetic parameters and breeding values were estimated based on data (“estimating dataset”) collected from September 2004 to March 2019. Predictability of parental breeding value estimates (EBVs) for the performances of progeny of the control group was evaluated on another dataset (“testing dataset”) using linear model equations involving parental EBVs classified into sex and age groups. The parental EBVs of animals in the testing dataset were traced by pedigree relationships of animals in the estimating dataset. Heritability estimates of CWT, BFT, EMA, and MAR were 0.53, 0.43, 0.38, and 0.54, respectively. Genetic correlation coefficients of CWT with BFT, EMA, and MAR were +0.32, +0.59, and +0.11, respectively. Environmental correlation coefficients of CWT with BFT, EMA, and MAR were +0.46, +0.55, and +0.29, respectively. In the testing dataset, partial regression coefficients of phenotypic values of progeny on sire EBVs ranged from +0.43 to +0.60 depending on traits fit into the models, while those on dam EBVs ranged from +0.54 to +0.67. All partial regression coefficients were statistically significant and were approximated to the expected value of +0.5. Together, these values validate the use of parental EBVs for predicting progeny carcass phenotypes in the Hanwoo herd.
The conformational characteristics and performance of the horse breed should be evaluated to establish the breeding goals for a riding horse breed. Halla horses are cross-bred from Thoroughbred horses and Jeju ponies. Halla horses have been bred for speed as racing horses in Jeju Island in South Korea. However, some horses have also been used for riding purposes. Thus, the main purpose of this study was to evaluate the characteristics of Halla horses for riding purposes, which can be used as a guideline to define the breeding goals of Halla horses. Therefore, we evaluated the athletic performance of Halla horses by analyzing 3-year records of dressage (from S-3 Class to F Class) and show-jumping competitions (from S-2 Class to G Class) held in South Korea. We also examined the conformational characteristics of 15 Halla horses and compared them with those of 15 Thoroughbred and 15 Warmblood horses. In the results of dressage competitions over 3 years, Halla horses were awarded in D Class dressage only. In contrast, in the show-jumping competition, Halla horses were awarded in the D, E, F, and G classes. Overall, most body parts measured were smaller than those of Thoroughbred and Warmblood horses. When the rate of body parts per the average height of each breed was compared, Halla horses showed a higher rate of head length, head perimeter, and lumbar back length and croup length. In contrast, Halla horses had a shorter neck length. Based on the results of horse competition and conformation analysis, it is concluded that Halla horses are suitable for youth show-jumping competitions and have the potential to be representative riding horses in South Korea.
This study was designed to investigate the effect of parity and lactation stage of sows on the behavior of nursing sows and their suckling piglets. In total 18 Yorkshire × Landrace F1 sows (range of parity: 1 to 6) and their litters (range of litter size: 10 to 14 piglets) were assigned according to the sow's parity (1-2, 3-4 and 5-6) and lactation stage (early, middle, and late). The sows were housed in farrowing crates (0.8 × 2.1 m) located in pens (2.1 × 1.75 m) with totally perforated flooring. The behaviors of the sows and their piglets were recorded over a 72-h period for each parity and lactation stage. The sows and piglets were conventionally managed. All nursing sows in both group showed lying behavior for more than 80% of the experimental period, regardless of parity and lactation stage. The behavioral frequency of sows was, in descending order, as follows: lateral lying, ventral lying, eating, standing, and sitting. The parity of sows did not affect their behavior, but the lactation stage did. Ventral lying showed decreased frequency in late stage compare to that in the early or middle stage. The lying, standing, sitting, and eating behavior of sows were not affected by their parity. Sow parity did not affect the behavior of suckling piglets, but the lactation stage did. The behavioral frequency of piglets for the whole lactation period was, in descending order, as follows: lying, suckling, and walking. The lying frequency of piglets was higher in the sow's middle lactation stage than in the early or late lactation stage. It is concluded that the sow parity did not affect the behavior of nursing sows and suckling piglets, but the lactation stage did.
The objective of this study was to investigate the effects of gender on meat quality traits and sensory characteristics of pork loin. A total of 90 pork carcasses (180 days old, 45 barrows and 45 gilts, each gender group was consisted of fifteen 1+, 1 and 2 carcass grades) were selected and loin cuts were excised to investigate meat quality, electronic tongue measures and sensory panel test. There were significant differences in drip loss (1.66% vs 1.21%), released water (12.19% vs 10.68%) and cooking loss (23.67% vs 21.04%) between loins from barrow and gilt (p<0.05). However, no significant differences in meat color (CIE L* a* b*) and shear force were observed between gender groups (p>0.05). Umami and richness values of barrow were significantly higher than those of gilt, while barrow had significantly lower sourness value compared to gilt (p<0.05). On the sensory evaluation, barrow scored higher in flavor, juiciness and tenderness both, and as a result, barrow (5.51 points) also scored significantly higher than gilt (4.86 points). These results suggest that the umami intensity and sensory taste of barrow loin are superior to gilt loin due to its high water-holding capacity.
This study was conducted to investigate the effects by supplementing concentrates during the late fattening phase in TMR (total mixed ration) feeding of Korean steer on the performance, carcass traits, physico-chemical characteristics and sensory test of the longissimus dorsi muscle. Eight Korean steers (24 months of age) averaging 604 kg in body weight were fed the TMR (Control) or the TMR supplemented with concentrates (TMR+conc.) until 30 months of age, then they were slaughtered. Steers fed the TMR supplemented with concentrates had a higher (p<0.05) intakes of dry matter and TDN (total digestible nutrient), carcass weight and marbling score compared to those fed TMR only, but carcass grade did not differ (p>0.05) between treatments. Amino acid concentration of the longissimus dorsi muscle did not differ between treatments, However, the highest concentrations were for glutamic acid and lowest for cystine; further, and the content of essential amino acids was highest for lysine, leucine, threonine, arginine, and isoleucine in that order. Cis-oleic acid and arachidonic acid of fatty acids in the longissimus dorsi muscle were higher (p<0.05) in the control condition compared to TMR+conc. The contents of oleic acids, palmitic acid, stearic acid constituted about 88% of the total fatty acids. Although the physico-chemical characteristics of the longissimus dorsi muscle did not significantly differ between treatments (p>0.05), but the sensory test results were lower for the TMR+conc. condition. These results suggest that supplementing concentrates during the late fattening phase of Korean steers resulted in increasing the carcass weight and marbling score. However, the cis-oleic acid content of the longissimus dorsi muscle was decreased as a result of supplementing concentrates, which could affect negatively in meat sensory evaluation.
collected from approximately 1100 purebred Duroc pigs between 2011 and 2017. The meat quality traits evaluated were: moisture content (MC), fat content (FC), water holding capacity (WHC), cooking loss (CL), and shear force (SF). Meat samples were evaluated for the following fatty acids: palmitic, stearic, oleic, linoleic, and linolenic acids. We evaluated the meat for the following sensory traits: color, flavor, tenderness, juiciness, and acceptability of the meat. Variance and covariance components were estimated using restricted maximum likelihood procedures on different animal models. The results showed that the estimates of heritability for MC, FC, WHC, CL, and SF were 0.17, 0.58, 0.34, 0.31, and 0.42, respectively. The heritability estimates for fatty acid composition were moderate to high (0.34 to 0.63). The estimates of genetic correlation were -0.60 and 0.46 between MC and FC, and MC and SF, respectively. Generally, phenotypic correlation between meat quality traits was low. Linoleic acid had moderate to high negative phenotypic and genotypic correlation with both palmitic and oleic acid. Comparison of meat quality traits and sensory traits revealed a positive correlation (0.208) between acceptability and WHC, while the correlation between acceptability and SF was negative (-0.207). The estimated genetic parameters among meat quality traits, sensory traits, and fatty acid composition in this study are expected to be used to improve pork to suit consumer preferences.
Due to lack of established operating conditions, the swine manure management process circulates bio-liquor between the slurry pit and the bioreactor process cannot be effectively used yet. Therefore, a lab scale study comprising a single bio-reactor and slurry pit was conducted to investigate the optimal operating conditions. The main experiment was performed after conducting a preliminary study on the operating conditions. In the preliminary study, the volume ratio of the bioreactor to the slurry pit was fixed at 1 and hydraulic retention time (HRT) of the bioreactor was set as 5, 10 and 15 d. In the main experiment, the HRT of the bioreactor was fixed at 5 d based on preliminary results and the ratio of bioreactor to slurry pit was set at 1:3, 1:5, 1:7 and 1:10. Since, a decrease in bioreactor performance occurred when NH4-N loading rate reached 60 g/m3/d, the loading rate of NH4-N was required to be maintained below 55 g/m3/d to achieve stable operation. Although manure excretion can definitely increase the loading rate into the bioreactor as well as NH4-N concentration in the slurry pit, the NH4-N in slurry pit can be kept consistent with the circulation rate above 9.5Q (ratio to manure excretion). The optimal volume ratio of the bioreactor to the slurry pit and HRT of the bioreactor to fulfill these operating conditions was 1:3 and 5d, respectively. Notably, studying of the individual farm situation is very important to establish an ideal method to apply the optimal operation conditions suggested in this study.