Food safety accidents like the occurrence of domestic animal diseases create an air of anxiety in consumers and increase their concerns about animal welfare. This study investigated consumer awareness of animal welfare livestock and attempted to look into the impacts of consumer awareness on the consumption of livestock product. It analyzed whether there was any difference in considerations of purchasing livestock products depending on awareness of animal welfare and consumption intention using Levene's equal variance test and independent sample t-test, and in order to inquire into the influence relationship of their considerations in purchasing livestock on animal welfare livestock product consumption intention, a binary logistic regression analysis was carried out. As a result of the analysis of consumer awareness, consumers were little aware of animal welfare while they were very interested in animal welfare and had the intent to consume livestock products produced following animal welfare. As a result of the analysis of the difference depending on the awareness and consumption intention of animal welfare using independent sample t-test, it turned out that there was no difference in considerations in purchasing livestock products between people who were aware of animal welfare and those who were not. In the difference depending on consumption intention, people who had the intent to consume animal welfare livestock products cared more than those who did not. Likewise, people who had the intent to consume animal welfare livestock products cared about the place of purchase, price, freshness, taste and quality more than those who were not. As a result of the binary logistic regression analysis of the two factors of internal property and external property of consideration in livestock products, it turned out that internal property only had impacts on consumption intention. Thus, considering the consumers' consciousness that they would like to be provided with safe livestock products relevant to items such as safety and reliability among their considerations in purchasing livestock products, the government and livestock industry should establish an appropriate marketing strategy for animal welfare livestock products
γ-Aminobutyric acid (GABA) is present in many vegetables and fruits, but not in dairy products. GABA is known to be beneficial for preventing neurological disorders and hypertension. The objective of this study was to measure the physicochemical changes, number of lactic acid bacteria, and GABA content in fermented goat milk containing rice (1%). The levels of pH and titratable acidity (TA) in each test samples were found to be pH 4.4∼4.5 and 0.74∼0.8%, respectively. The number of viable lactic acid bacteria between test samples ranged from 8.63 to 8.95 Log CFU/ml. Therefore, pH, TA, and number of viable cells in each test sample had no difference. Furthermore, the Lactobacillus delbrueckii subsp. bulgaricus SP5 (Lb. bulgaricus SP5) showed the highest GABA production in goat milk containing rice. Its maximum GABA yield was 3.4 mg/100 mL. The results suggest that GABA contents of fermented goat milk containing rice can be enriched using Lb. bulgaricus SP5.
The occurrence of mastitis in diary cattle has been caused by genetic, physiological, managemental and environment factors accounted for the highest percentage of worldwide disease in dairy cattle. The purpose of this study was to analyze the occurrences and causative bacteria of subclinical mastitis in milking cows and also examine the distribution of bacteria in milk by isolating and identifying bacteria both in whole milk and quarter milk. 31.4% of the milking cows suffered subclinical mastitis, and 9.5% had it in terms of quarter milk. According to the results of analyzing bacteria in quarter milk of which somatic cell count (SCC) was over 500 thousand, 15 kinds of bacteria were isolated, and among them, Pantoea spp. formed the biggest part as 15.8%. From whole milk, 37 kinds of bacteria were identified, and among them, Klebsiella oxytoca showed the highest identification rate as 30.1%. According to the results of bacteria analyzed from the quarter milk of entire milking cows, 52 kinds of bacteria were identified. Among them, 17 kinds of Staphylococci were isolated, and CNS (Coagulase-Negative Staphylococci) formed a large part as 44.9%. The findings of this study showed that various kinds of bacteria were isolated from cows having subclinical mastitis; therefore, when managing specifications about milking or such, dairy farm will have to take proper action like performing sanitary control or counting somatic cells regularly in order to do their best for reducing mastitis.
Horses are non-ruminant and monogastric animal. If concentrates are fed plentifully at a time, undigested starch reaches large intestine and it activates amyloytic bacteria. Finally, it lowers a pH level and causes colic. Therefore, standard feed of concentrates and period of feed are important factors to fat up horses. This study was conducted to evaluate the productivity and carcass quality, quantity grade for Jeju horse (24 month old) with different fattening periods (4-, 8- and 13.5-month). The body weights were increased as the fattening periods increased and the increase rate was highest at 4-month group. The daily weight gain was decreased as the fattening periods increased such as 0.46 kg for 4-month group, 0.39 kg for 8-month group and 0.34 kg for 13.5-month groups. The daily intake was increased as the fattening periods increased such as 4.42 kg for 4-month group, 5.00 kg for 8-month group and 5.26 kg for 13.5-month groups. The daily feed conversion was increased as the fattening periods increased such as 11.71% for 4-month group, 17.69% for 8-month group and 18.53% for 13.5-month group. The backfat thicknesses and loin-eye areas were 3.50 mm, 83.50 ㎠ and increased to 4.20 mm, 94.00 ㎠ until they were fattening up for 8-month then they were decreased to 4.00 mm, 89.40 ㎠ when they were fattening up to 13.5-month. There was no significant difference in the meat color among 3 fattening groups, however, the a-values (redness) of meat color and b-values of fat color were highest (5.0 and 3.80, respectively) for 13.5-month group. The texture was not significantly different among 3 fattening groups. The maturity levels were in the 3.8∼4.5. All horses used in the experiment had the quality grade 2 and the horses for 13.5-month group had the quantity grade A, whereas the horses for 4-month group had the quantity grade B or C. Jeju horse had the low quality grade (quality grade 2) although the carcass yield increased when they were fattened from 24 month to 37.5 month.
Antler of deer have been used in Asia as a dietary supplementary or alternative medical substance. The antler contains various biological active substances, including ganglioside has been known to promote growth, bone hyperactivity, immune function, protein synthesis and various pharmacological action. Therefore, this study was to investigate the effect of antler on productivity of broiler chicks. Feeding trial has a number of 240 broiler chicks was conducted to investigate the effect of antler extract (AE) treated feeds on body performance, breast meat composition and characteristics in broilers. Each treatment had 15 chicks with 4 replications. The supplementation level of AE treated feeds was 0.3, 0.6 and 0.9% in the experimental diets. The results obtained were summarized as follows: Average body weight gain was significantly (p<0.05) increased in broilers fed with AE compared to that of control during overall periods. Especially, the body weight gain of 0.9% AE treated chickens showed highly increased by 6.0% compare to the control. Average feed intake was not significantly different among the treatments. Average feed efficiency was significantly (p<0.05) improved by 4% in broiler chicks fed with AE compare to that of control. Average breast meat composition and concentration of cholesterol were also not different by feeding the AE. In breast meat characteristics, the shear force (kg/0.5inch2) of breast meat showed similar results in all treatments. The cooking loss of breast meat was significantly lower in the chick fed AE than that of control. But the water holding capacity (%) of breast meat was significantly (p<0.05) higher in the chicks fed AE than that of control. In breast meat color of chicks were not significantly different in all treatments. The thiobarbituric acid reactive substances (TBARS) and volatile base nitrogen (VBN) value were not showed different with all treatments. Also, the fatty acids composition of breast meat were showed similar results in all treatments. In conclusion, the dietary feed of AE tended to improve the body weight gain and feed efficiency, but did not influenced breast meat characteristics of broiler chicks
Presently, the first pregnancy age of dairy heifers attended National Dairy Herd Improvement Program (NDHI) in Korea has increased, and more research have been requested to evaluate the possibility of decreasing the first pregnancy age of dairy heifers. Accordingly, this study was investigated the effects of the month of age at the first service and pregnancy on the reproductive efficiency of Holstein heifers. For these, the reproductive performance of heifers was analyzed by evaluating the effects of first insemination service at 12-14 months of age (12 month old), 15-16 months of age (15 month old), 17-19 months of age (17 month old), and > 20 months of age (20 month old) in Holstein heifers. The service numbers per conception in the first insemination months were 1.85±1.22, 1.59±0.77, 1.58±0.72, and 1.76±0.97 times at 12, 15, 17 and 20 months of age, respectively. The conception rates in the first service were 51.2, 57.8, 54.8, and 52.9% at 12, 15, 17 and 20 months of age, respectively. The conception ages were 453.2±78.9, 512.1±75.9, 590.1±98.0, and 713.0±74.5 days in the heifers serviced firstly at 12, 15, 17 and 20 months of age, respectively. There was significantly difference in the conception age among groups (p<0.05). The cumulative conception rates in the heifers serviced firstly at 12, 15, 17 and 20 months of age were 51.21, 57.8, 54.8 and 53.0% by the first service, 29.8, 30.1, 32.3, 23.5% by the second service, and 19.0, 12.1, 12.9 and 23.5% by the third service, respectively. The service numbers per conception in the first pregnancy months were 1.31, 1.55, 2.0, 2.05 times at 12, 15, 17 and 20 months of the first service age, respectively. The service numbers per conception in the 12 and 15 months of age were significantly lower than those in the 17 and 20 months of age (p<0.05). The rates of repeat-breeder were 6.0, 11.3, 22.0, and 41.0% in the heifers serviced firstly at 12, 15, 17 and 20 months of age, respectively. These results demonstrate that first pregnancy of Holstein heifers should be conducted at 15 months of age, because the age at first pregnancy in heifers can be substantially influenced through implementation of reproductive management and performance.
Cattle breeds were classified previously into three different haplogroups (Y1 and/or Y2 in Bos taurus and Y3 in B. indicus) based on Y chromosome-specific polymorphisms. In particular, a rapid and unambiguous classification method was reported recently. However, a haplogroup classification of Korean native cattle breeds has not been reported. In this study, 196 animal samples from four Korean native cattle breeds (Hanwoo, Chikso, Heugu, and Jeju black cattle) and six exotic breeds were used to determine the Y chromosome-specific haplogroup classification. We amplified an 81 bp indel region within intron 26 of the USP9Y gene and performed electrophoresis to classify the Y1 and Y2 haplogroups. Moreover, enzyme digestion was carried out with the SspI restriction enzyme to classify the Y2 and Y3 haplogroups. Finally, sequence variation in each haplogroup was confirmed by DNA sequencing. All animals in the four Korean native cattle and two exotic breeds (Charolais and Simmental) belonged to the Y2 haplogroup. Three other exotic breeds (Holstein, Angus, and Hereford) belonged to Y1 haplogroup. Japanese black cattle were divided into both the Y1 and Y2 haplogroups. The Y3 haplogroup corresponding to B. indicus was not found in this study. In conclusion, Korean native cattle breeds originated from B. taurus without introduction from B. indicus. In addition, they showed the same paternal heredity pattern which belonged to only Y2 haplogroup. These results can be used to investigate the origin of Korean native cattle breeds.
The objective of this study was to estimate genetic parameters for 18 linear conformation traits and overall conformation score in Holstein cattle. A total of 376,606 records for type traits were collected from 2001 to 2011 from Korea Animal Improvement Association. The model of estimation of variance components and correlations among lactations using VCE included both fixed effects (herd-year-season and stage of lactation parity-wise) and random effect (animal additive genetic). The estimated heritabilities (h2) for capacity class, such as stature, chest width, body depth, angularity, and body condition score were 0.32, 0.16, 0.27, 0.12, and 0.19, respectively. Rump angle and width from rump class also showed h2 of 0.31 and 0.17, respectively. The heritabilities in udder class were mostly low to medium; in which traits were fore udder attachment (0.13), rear udder height (0.17), udder support (0.11), udder depth (0.33), front teat placement (0.17), front teat length (0.21), and rear teat placement (0.21). For feet and legs composite class, the estimated heritabilities for rear leg set, foot angle, rear leg rear view, and locomotion were 0.12, 0.07, 0.08, and 0.03, respectively. The h2 estimated for overall conformation score was 0.16 in the study. The genetic and environmental variance components estimated from this study would be helpful to change from single lactation animal models to multiple lactation animal models in the national genetic evaluation system for the improvement of linear type traits. Moreover, The breeding values obtained using these variance components would be able to be used in the calculation of Korean type production index (KTPI), udder composite (UDC) and, feet and legs composite (FLC).
Selection based on phenotype in the traditional manner does not help in tracking the selected gene. Molecular genetics has revolutionized the old established breeding techniques. A new epoch of molecular markers has been acquainted for genetic improvement of livestock. This study is engaged on the neoteric molecular markers used in various fields of livestock. DNA markers are more encouraging in selecting genomes that have recombination events close to the target gene. Molecular markers rely on DNA assay and are better than the morphological and biochemical markers. In this study DNA-based molecular markers developed during the past decagons for animal genome analysis are reviewed. Mapping of molecular markers provide a framework, required for its subsequent use in the selection procedure. Molecular techniques help in the utilization of genetic variability in breeding population. At the same time livestock genomes play important role in human genomics and their role for understanding human genomics cannot be overlooked. Recently, in the epigenetic and transcriptomic studies, RNA sequencing as a part of next generation sequencing has revolutionized the approach and ongoing trends of analysis. Keeping in mind the goals, these molecular techniques can be implemented successfully by following well defined, crisp and integrated strategy.
With increasing concerns for the animal welfare, it is required to do a study on consumer's awareness about the necessity of animal welfare products. Thus, the purpose of this study was to analyze the consumers awareness about the necessity of animal welfare products. Especially, in this study, animal welfare egg was focused in Korea. Data were collected by consumer survey at Hanaromart in Chuncheon on November 4th, 2011. SAS 9.1 and Excel 2007 were used as statistical packages and ranked logit model was used as a tool for analysis. The results of this study were as follows. Variable c1 had significant probabilities in categories of “over 40s” for age and “under 3 persons" for family size. Variable c2 had significant probabilities in categories of “over 40s” for age, “over 3 million won” for monthly income and “under 3 persons” for family size. Variable c3 had significant probabilities in categories of “over 3 million won” for monthly income and “under 3 persons” for family size. Variable c4 had significant probabilities in categories of “married” for marital status, “over 40s” for age, “over 3 million won” for monthly income and “under 3 persons" for family size. Variable c5 had significant probabilities in categories of “married” for marital status, “over 40s” for age, “over 3 million won" for monthly income and “under 3 persons" for family size. Variable c7 was ranked as the first reason in the categories of “male” for gender, “under 3 million won" for monthly income and “under 3 persons" for family size. Variable c2 was ranked as the first reason in the categories of “single” for marital status, “under 40s” for age and “over 4 persons" for family size. Variable c3 was ranked as the first reason in the categories of “married” for marital status and “over 40s” for age. The results of this study provide important information to policy makers and farmers. The policy makers can use the results when they will make policies related with the animal welfare, and the farmers can use the results when they will make marketing strategies. This study had a few limitations that the survey was conducted at a city, and at a mart. In spite of the limitations, this study will provide important information to future studies
The aim of this study was to compare the effects of different thawing methods including; refrigerated at 4℃ for 6 hr, soaked in 15℃ water for 40 min, exposed to room temperature (25℃) for 4 hr, and microwaved (600 W) for 2 min on the water-soluble nutritional component and meat quality trait of Hanwoo beef. The thawing beef by the refrigerated method resulted in significantly lower cooking loss, drip loss and loss of water-soluble vitamin B group, whereas the water-soaked method had higher loss of vitamin B group (p<0.05). Furthermore, total aerobic counts and coliforms were significantly lower in the meat samples thawed by the refrigerated method than that in the samples thawed by the other methods when stored for 6 days at 4℃. However, the thiobarbituric acid reactive substance (TBARS) content was found significantly (p<0.05) higher in the microwaved method than that in the other thawing methods. Based on the results obtained in the present study, it is concluded that the thawing methods had remarkable impact on the water-soluble nutritional components, quality properties and storage stability of meat. Therefore, the present study recommends that the thawed meat needs to be consumed and should not be stored for long time due to the acceleration of its quality deterioration
Recently, with the increase of meat production, high quality and safety of meat have been strongly emphasized by Korean consumers. Marbling in beef has been regarded as an important criterion deciding meat quality in Korea. The purpose of this study was to identify the transcriptional level of insulin-like growth factor-1 (IGF-1) in longissimus muscle samples of 46 Hanwoo. The level of IGF-1 transcripts was measured by real-time polymerase chain reaction (PCR) and molecular connection of IGF-1 was analyzed using the Pathway Studio program (Ver 9.0). Increase of marbling score (MS) induced increase of IGF-1 transcripts level in the muscle and there is a significant correlation (p<0.05) between IGF-1 mRNA expression and MS. The pathway study showed that IGF-1 genes are regulated in insulin, fatty acid synthase, leptin, and corticotrophin releasing hormone. These results suggest that IGF-1 might be used as a useful marker for the improvement of economic traits in Hanwoo.
This research was conducted to estimate the effect of packaging methods on the color and taste-related precursors in Hanwoo (Korean cattle) beef during aging. Following packaging with vacuum (VACP), low oxygen-modified atmosphere (LOMAP; 0% O2/20% CO2/80% N2) or vacuum skin+LOMAP (VSP+LOMAP), the loins and top rounds were aged at 2℃ for 14 days and lipid oxidation (TBARS content), surface color, glucose and lactate contents were measured. TBARS and glucose contents were not different by packaging methods in both loins and top rounds. The a* (redness), b* (yellowness) and C* (chroma) values were higher (p<0.05) in VACP-aged beef as compared to the other beef. Lactate content was significantly higher (p<0.05) in both LOMAP- and VSP+LOMAP-aged beef than in VACP-aged beef at day 14 of aging. These findings suggested that VACP was the most effective in maintaining color stability but LOMAP was more effective in maintenance of some taste-related precursor compared to VACP.
The aim of this study was to develop the production of crossbred pigs suitable to the Korean consumers’demand. Crossbred (Jeju native pig × Landrace) pigs (n=175) at the age of 200 days, approximately classified into three slaughter weight groups (59~95 kg, 96~110 kg and 111~148 kg) were used to investigate the carcass traits and retail cuts characteristics. We have chosen longissimus dorsi, triceps brachii, biceps femoris, semimembranosus muscles, shoulder butt, thoracic vertebra (5-11th) and last thoracic vertebra for investigations of aforementioned parameters. The results showed that the 111~148 kg group had larger loin area, higher scores for meat color, quality and carcass grade than the other remaining groups (p<0.05). Weights of shoulder butt, rib, picnic shoulder, loin, belly, tenderloin, ham retail cuts, lean meat, fat and bone increased with increasing carcass weight (p<0.05). Ratios of shoulder butt, picnic shoulder, tenderloin, ham, lean meat, skin and bone in the 59~95 kg group were higher than that of the other groups (p<0.05). Ratios of belly in the 96~110 kg group were higher than that in the 59~95 kg group (p<0.05) but similar to the ratios of the 111~148 kg group. Total length, longest length and shortest length of belly increased with increasing carcass weight (p<0.05). Additionally, the longest width and shortest width of belly in 59~95 kg group were lower (p<0.05) than that in the other remaining groups. Length of shoulder butt increased with increasing carcass weight (p<0.05) whereas, the width of shoulder butt showed no differences between the groups. Weights of triceps brachii of picnic shoulder, biceps femoris and semimembranosus muscles of ham increased with increasing carcass weight (p<0.05). Overall, the crossbred pigs of 111~148 kg group possessed better quality and carcass grade however, the yield of belly in 96~110 kg group was higher than the other groups. Based on the consumption preference of Korean consumers therefore, the slaughter weight of crossbred pigs at ≥96 kg could produce higher economic benefit.
A study was performed to investigate the effect of reseeding rates of Italian ryegrass (IRG)〔Lolium multiflorum L.〕on its nutritive value and productivity in native grasssland of Jeju region from Oct. 2011 to Jul. 2012. IRG was sown at reseeding rates (0 30, 40 and 50 kg/ha) in native grassland. When IRG was sown, there was no draught and lodging damage. Plant height in treatment 30 kg/ha of reseeding IRG was the tallest at all harvest stages (p<0.05). DM yield in treatment of 30 kg/ha of reseeding IRG was 12,790 kg/ha and increased 2.7 folds as compared to control. However, there was no significant difference among the treatments. The content of neutral detergent fiber (NDF) significantly decreased in treatment of reseeding, compared to control (p<0.05). In general, the content of NDF in second harvest stage was lower than that of control in first harvest stage. The content of acid detergent fiber (ADF) also showed simliar trend as content of NDF. The content of total digestible nutrients (TDN) in treatments of 30 kg/ha and 50 kg/ha of reseeding were approximately 45.2% each. The content of TDN in treatments of 30 kg/ha and 50kg/ha of reseeding increased as compared to 40 kg/ha and control of reseeding (p<0.05). Therefore, it is conclued that reseeding rate of IRG may improve the yield and nutritive values of IRG at 30 kg/ha.
This experiment was conducted to investigate effect of brine mineral water (BMW) on growth performance and properties of blood in weaning pigs. Treatments allotted were 0% (general water), 2%, 3% and 5% BMW. In growth trial, a total of 36 weaning pig barrows [(Landrace×Yorkshire)×Duroc] weaned after 21 days with an average initial weight of 5.38±0.89 kg were used. Each treatment had 3 replications of 3 pigs per pen in a randomized complete block design. Weaning pigs were investigated for growth performance, complete blood corpuscle count and blood biochemical assay. In results, growth performance of 2% and 3% treatment groups were significantly higher than other groups (p<0.05). In addition, high density lipoprotein cholesterol was significantly (p<0.05) higher in 2% group than other treatment groups. On the other hand, mean corpuscular volume of supplement of BMW treatment groups were significantly (p<0.05) increased than control. Therefore, this study suggests that supplementation of BMW could improve growth performance and level of red blood cell in weaning pigs.
The objectives of this study were to estimate genetic parameters for 10 linear conformation traits and final score in Hanwoo cows. A total of 53,277 records for type traits of Hanwoo cows were collected from 2008 to 2012 from Korea Animal Improvement Association. Ten linear traits studied were stature, body length, chest depth, body rump angle, rump length, pin bone width, udder volume, foot angle, rear legs side view, and rear legs rear view. The model included the fixed effects of herd-year-classifier, age at measurement and age after calving, the random animal additive genetic effect and residual effect. Heritability estimates for linear type traits were ranged from 0.003 for rear legs side view to 0.213 for final score. Genetic correlations among linear type traits were ranged from -0.068 (for rear legs side view and rear legs rear view) to 0.982 (for body length and rump length). The final score was found to be in a strongest genetic correlation with rear legs rear view (0.947), followed by pin bone width (0.918), body length (0.887), rump length (0.883), chest depth (0.883), udder volume (0.811), stature (0.802), rump angle (0.637), foot angle (0.519) and rear legs side view (0.176). Corresponding phenotypic correlations for pairs of linear type traits were mostly similar in direction, but smaller than the genetic correlations.
The objective of this study was to estimate genetic parameters on days to 90 kg body weight and ultrasound measured traits (back fat thickness, eye muscle area, retail cut percentage) and predict genetic progress when the weights for selection on the paternal traits of Duroc, which can be incorporated into sire line selection indexes. A simulation program, ZPLAN+, was used for the simulation. Genetic parameters of days to 90 kg body weight (D90KG), back fat thickness (BFT), eye muscle area (EMA) and retail cut percentage (RCP) used in the simulation were estimated from 27,972 heads of farm tested Duroc pigs from 2005 to July, 2012. Parameters of simulation used genetic parameters with parturition rates, ratios of test pigs and replacement rates that were dependent on selection protocols of simulated farms. Different weights of selection for traits of days to 90 kg and backfat thickness were compared. Estimates of heritability were 0.406, 0.355, 0.159 and 0.379 for D90KG, BFT, EMA and RCP, respectively. Genetic correlation of D90KG with BFT, EMA and RCP were –0.043, 0.049 and 0.021, respectively. Genetic correlation of BFT with EMA and RCP were –0.394 and –0.937. And genetic correlation between EMA with RCP were 0.524. Simulation result showed that index weight of 3:1 on D90KG and BFT was effective to shorten days to 90 kg without any significant changes in backfat thickness. Generally the genetic changes were greater as parturition rate and ratios of test pigs increased. Increase in replacement rate had a small effect on genetic changes in negative way. Thus, we recommend that index weight of 3:1 on days to 90 kg and backfat thickness could be utilized for sire line selection.
Single nucleotide polymorphisms (SNPs), that usually occurs with a modification in single nucleotide among the population of 1000 nucleotides. Such changes in nucleotides have been investigated and been associated by meat scientist for economically important traits and to increase economical profits in stock breeding. Pluralities in the study have correlated SNPs of potential candidate gene with economically important traits in domestic animals have been put forward. In chickens, INS, IGF1, IGF1R, IGFBP, CAPN1, CAPN3, GHSR, FATP1, FGFBP1, FGFBP2, apoVlDL-Ⅱ, PB1, miR-1614-3p, DAAM1, Wnt3A, LRP5, CHP, RHOA, MAPK9, SFRP1, ATGL, PGC-1α, NPY, GnRHR, PRL, TGFβ2, CASR. UCP, ADSL, STAT5b, LRP2 and CTSD genes have been found to have significant effects on body weight, breast muscle weight, carcass weight and egg number. For the similar reasons, SNPs of these genes have been considered useful DNA markers for the improvement economic value of poultry. Although further studies on different breeds of chickens would be required to segregate such dataset for different breeds of chickens.
The purpose of the study was to investigate an effect of water temperature on a non-specific immune response and mortality of tilapia, Oreochromis niloticus, following a bacterial infection. Seventy five tilapia acclimated to 25℃ were then transferred at 16 and 36℃, and examined for non-specific immune responses over 12-96 h. Respiratory burst activity was reduced significantly in the group of fish cultured at 16 and 36℃ over 24-96 h, whereas phagocytic activity decreased significantly in the group of fish reared at a low temperature (16℃) over 12 and 24 h and high temperatures (36℃) over 12-96 h. Lysozyme activity diminished significantly in the group of fish transferred to 16℃ over 12-48 h, but increased significantly in the group of fish at 36℃ over 48 and 96 h. Alternative complement pathway (ACH50) decreased significantly when transferred to 16℃ after 12 h, but increased significantly when transferred to 36℃ after 24 h. In a challenging test, 30 tilapia reared at 25℃ were injected intraperitoneally with Streptococcus iniae at a dose of 2x107 cfu/fish, and then reared onward at water temperatures of 15, 25 (control), and 36℃. Over 12-96 h, the cumulative mortality of S. iniae-injected fish held in 16 and 36℃ was significantly higher than that of injected-fish held in 25℃ In conclusion, transfer of tilapia from 25℃ to low temperature (16℃) after 12 h, and transfer of fish from 25℃ to high temperature (35℃) reduced their immune capability. Furthermore, tilapia under temperature stress at 16 and 36℃ from 25℃ decreased its resistance against S. iniae