• Animal Bioscience
• /
• v.36 no.4
• /
• pp.540-554
• /
• 2023

Heat stress is a major challenge to animal production in tropical and subtropical climates. Rabbits suffer from heat stress more than farm animals because they have few sweat glands, and their bodies are covered with thick fur. Intensive farming relies on antibiotics as antimicrobials or growth promoters to increase animals' productivity and health. However, the European Union and many countries have banned or restricted the use of antibiotics in animal feed for human health concerns. Several studies have found that replacing antibiotics in rabbit feed with natural plants or feed additives increases productivity and improves immune capacity, especially under heat stress conditions. Growth performance, immune response, gut microflora, and carcass yield may be increased in rabbits fed a diet supplemented with some natural plants and/or propolis. In this review article, we discuss and summarize the effects of some herbs and plant extracts as alternative feed additives on rabbit productivity, especially for those raised under hot ambient temperatures.

• Journal of Animal Science and Technology
• /
• v.44 no.6
• /
• pp.643-652
• /
• 2002

Data were consisted of the ten body measurements (withers height, rump height, body length, chest depth, chest width, rump width, rump length, thurls width, hipbone width and chest girth) of 642 steers (Korean cattle), which was entered in the National Beef Quality Contest hosted by the Korea Animal Improvement Association from 1997 to 2001. A principal components analysis was used to classify the body types of the steers, and estimate the correlations between carcass traits and principal components for the body measurements of the first, second, third and fourth period, respectively. The first principal component of body measurements at the first, second, third and fourth period accounted for 76.0%, 83.0%, 72.7% and 57.4% of the total variance, respectively. The sum of first, second and third principal component at each period accounted for 86.69%, 90.49%, 84.62% and 77.26% of the total variance, respectively. At each period, all the first principal component of the body measurements were positive and it generally showed large framed body shape. The size of body was influenced mostly by chest depth(0.328${\sim}$0.339) and rump length(0.325${\sim}$0.341). The second, third and fourth principal component at the each period were various. There were positive correlations between principal components index of each period and carcass traits such as carcass weight(0.539${\sim}$0.755), average daily gain(0.256${\sim}$0.564), backfat thickness(0.227${\sim}$0.280), and eye muscle area(0.187${\sim}$0.344). The correlation with yield grade index(－0.246${\sim}$－0.110), however, was negative. The correlation with marbling score(0.066${\sim}$0.099) was low or statistically insignificant. According to principal component indexes of the second, third, and fourth components, the correlations with the carcass traits were various. There were no large differences between the correlations of the single body measurement trait with the carcass traits and the correlations of the first principal component indexes with the carcass traits.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.8
• /
• pp.1201-1206
• /
• 2008

The effects of free-range farming, compared to a conventional production system, on carcass and meat qualities were studied using black-feathered Taiwan native chickens. Twenty 16-week old females were purchased separately from a free-range farm and a conventional production farm and used for this study. The results showed similarities in the live weight (roughly 2.1 kg), dressing percentage (69%) and meat percentage (19%) of deboned leg quarter. Significant differences (p<0.05) found for the free-range chickens included: a higher percentage of meat for the breast, an increased crude protein content and chewiness value for the breast, but decreased crude fat content and lower hardness and fracturablility values for the leg quarter. Significantly higher L* values were found for the breast and leg meat of conventionally produced chickens, whereas no significant differences were found for WHC and purge loss between the breast and the leg, and between the two production systems as well. Results of sensory evaluation showed a significant preference for leg over breast meat (p<0.05). The scores of all the attributes including aroma, flavor, firmness, tenderness, juiciness and overall acceptability of leg meat from free-range chickens were slightly higher than for conventional chickens, while the reverse was true for breast meat, though no significant difference could be found. Free-range Taiwan native chicken appeared to yield the best of the results, with flavorful yet tender leg meat for higher sensory satisfaction, and high-protein but low-fat breast meat for healthier diet choice.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.36 no.3
• /
• pp.191-198
• /
• 2016

This study evaluated the effects of TMC (trace mineral-fortified microbial culture) supplementation on growth performance, carcass characteristics, and meat quality parameters of Hanwoo steers during the last 4 months of finishing period. The TMC was a combination of 0.4% trace minerals, 20.0% Na-bentonite, and 79.6% feedstuffs, which was inoculated with a mixed microbial culture (Enterobacter ludwigii, Bacillus cereus, B. subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae). Twenty-four steers were blocked by initial BW ($634{\pm}16kg$) and randomly allocated to one of two treatments (control vs. 3.3% TMC). The effect of TMC supplementation on the growth performance was not significant. There was no incidence of urolithiasis in TMC-fed steers. However 3 out 12 steers (25%) fed the control diet were observed to have urinary calculi. The carcass yield and meat quality parameters were not affected by TMC supplementation, however marbling score was increased in TMC-fed steers (P = 0.08). There was no effect of TMC treatment on the chemical composition of longissimus dorsi muscle (LM). The TMC supplementation increased concentrations of manganese (P < 0.01), cobalt (P = 0.02), iron, and copper (P = 0.06) in LM. In conclusion, TMC treatment did not negatively affect growth performance and meat quality parameters, and positively affected the trace minerals profile of LM.

• Food Science of Animal Resources
• /
• v.31 no.4
• /
• pp.530-536
• /
• 2011

It is well established that uncoupling protein 3 (UCP3) is expressed largely in skeletal muscle, white adipose tissue and brown adipose tissue and has been suggested to play important roles in regulating energy expenditure, body weight, thermoregulation as well as fatty acid metabolism and obesity. Therefore, the UCP3 gene was selected as a candidate gene for carcass and meat quality traits in Korean cattle. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the UCP3 gene and to evaluate the association of UCP3 SNP markers with carcass and meat quality traits in Korean cattle. The five exons in the UCP3 gene were sequenced, and ten SNPs were identified. The PCR-SSCP method was then developed to genotype the individuals examined. The g.3076A>G genotype was significantly associated with marbling score (MS) of Korean cattle. Animals with the AA genotype had a higher MS than those with the AG and GG genotypes. No significant associations of the SNP g.3076A>G were observed for any traits. In conclusion, although SNP g.3076A>G, which showed an association with MS, does not cause amino acid changes, this SNP may be used as a DNA marker to select animals that have higher intramuscular fat content.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.11
• /
• pp.1569-1575
• /
• 2016

Two experiments were conducted to examine the influence of kaolinite clay supplementation (0%, 1%, or 2% diet dry matter [DM] basis) on characteristics of digestion (Trial 1) and growth performance (Trial 2) in calf-fed Holstein steers fed a finishing diet. In Trial 1, 6 Holstein steers ($539{\pm}15kg$) with ruminal and duodenal cannulas were used to evaluate treatment effects on characteristics of digestion. Kaolinite clay supplementation decreased total tract DM digestion (linear effect, p<0.01) without effects ($p{\geq}0.10$) on site and extent of digestion of organic matter, neutral detergent fiber, starch and N, or ruminal microbial efficiency. There were no treatment effects on ruminal pH, volatile fatty acids molar proportions or estimated methane production. In Trial 2, 108 Holstein steers ($132.4{\pm}5.6kg$) were used in a 308-d study to evaluate growth performance and carcass characteristics. There were no treatment effects (p>0.10) on average daily gain (ADG) and gain efficiency (ADG/dry matter intake). Kaolinite supplementation tended (linear effect, p = 0.08) to increase dietary net energy (NE) during the initial 112-d period. However, the overall (308-d) effect of supplementation dietary NE was not appreciable (p>0.20). However, due to the inertness of kaolinite, itself, the ratio of observed-to-expected dietary NE increased with kaolinite supplementation. This effect was more pronounced (linear effect, $p{\leq}0.03$) during the initial 224 d of the study. Overall (308 d), kaolinite supplementation tended to increase (linear effect, p = 0.07) dietary NE by 3% over expected. Kaolinite supplementation did not affect carcass weight, yield grade, longissimus area, kidney, pelvic and heart fat, and quality grade, but decreased (linear effect, p = 0.01) dressing percentage. It is concluded that kaolinite supplementation up to 2% of diet DM may enhance energetic efficiency of calf-fed Holstein steers in a manner independent of changes in characteristics of ruminal and total tract digestion.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.4
• /
• pp.538-544
• /
• 2005

The present experiment was conducted to assess the effect of reconstitution (R) on utilization of red sorghum (S) in diets of broiler chickens. Day-old broiler chicks (n=360) were randomly divided into 36 groups of 10 chicks each, and 9 dietary treatments were allotted to 4 groups (replicates) in a completely randomized design. Out of the 9 treatments, one was corn-soy based control (D1). The rest of the treatments were diets consisting of four levels (25, 50, 75 and 100% part of corn) of raw red sorghum (S25-S100) or four levels of reconstituted red sorghum (RS25-RS100). The tannin content reduced from 2.3% to 1.6% after reconstitution of red sorghum. Body weight gain reduced significantly (p<0.01) in diets containing unprocessed red sorghum beyond 33% in diet or reconstituted red sorghum at any level. However, during finishing growth phase the birds receiving either processed or unprocessed sorghum (barring S75) had statistically similar gains in body weight. During over all growth phase (0-6 wk), live weight gains in all the dietary treatments did not differ statistically. Feed intake during 0-6 wk was significantly higher (p<0.05) in diets containing sole red sorghum than corn-soy based control diets Feed conversion ratio during 0-3 wk period in control and unprocessed red-sorghum diets were similar but statistically poorer (p<0.01) FCR emanated from reconstituted groups, while during 3-6 wk of age FCR was poorer (p<0.05) in diets containing 75% red sorghum, either processed or unprocessed. FCR, in overall growth phases, in control diet was statistically similar to the groups fed diets containing up to 33% unprocessed or 16% reconstituted group. The carcass traits and yield of organs did not differ (p>0.05) due to the various levels of red-sorghum. It was concluded that though the tannin content was reduced by 30% by the reconstitution process, but this did not give any additional advantage in broiler performance. More over, red-sorghum can be used effectively up to 33% in diet replacing 50% of corn after proper adjustment of proteins, energy and amino acids.

• Korean Journal of Poultry Science
• /
• v.44 no.3
• /
• pp.161-172
• /
• 2017

This study was conducted to determine the effect of Saccharomyces cerevisiae (SC) as a dietary probiotic and evaluated the most suitable feeding interval for this probiotic on growth performance, carcass yield, and meat quality parameters in broiler chickens. In total, 1,050 one-day-old Cobb 500 chicks were randomly assigned to one of seven dietary treatment groups, in a $2{\times}3$ factorial arrangement with 3 SC dosages (0.6%, 1%, and 1.4%) and two feeding intervals [long term (LT) for 35 days and short term (ST) for 28 days after hatching], with a negative control diet (NC; 0% SC). Triplicate experiments were performed with 50 birds per cage. Broilers fed a diet including SC showed increased (p<0.01) daily gain and feed efficiency compared to the control. Further, broilers fed the 1.4% SC supplemented diet showed a significantly increased (p<0.01) average daily gain (ADG) and feed conversion ratio (FCR) compared to broilers fed the 0.6% and 1% SC incorporated diets. Similarly, broilers fed an LT SC diet showed a greater (p<0.01) increase in ADG and FCR compared to broilers fed an ST SC diet. Moreover, broilers fed an LT SC diet displayed a reduced (p<0.05) meat pH, gizzard weight, and increased (p<0.05) meat water-holding capacity compared to broilers fed an ST SC diet. Broilers fed the 1.4% SC supplemented diet showed increased (p<0.05) thigh muscle weight compared to broilers fed the 0.6% and 1% SC supplemented diets. In conclusion, broilers fed LT SC diets showed improved growth performance and carcass quality parameters compared to broilers fed ST SC diets, and the NC diet, from hatching to day 35.

• Animal Bioscience
• /
• v.36 no.2
• /
• pp.322-332
• /
• 2023

Objective: We determined the impact of maintaining pasture-based dairy cows and calves together over 100 days on cow milk production, cow and calf behavior, and calf liveweight and carcass quality. Methods: Six Holstein-Friesian cows and their male calves were monitored for 106±8.6 days. Cows were temporarily separated twice a day for milking with calves remaining in the paddock. Cow and calf behaviors were recorded via scan sampling at 6 different timepoints, for the first 7 days and twice a week thereafter. Calves were weighed weekly and immediately processed for meat quality and rumen development analysis at 106±8.6 days. Daily cow milk yields were collected from enrollment until 109±8.6 days (3 days post-weaning). Results: The average daily gain of calves was 1.4±0.73 kg/d, with an average carcass dressing percentage of 59%. Calves had the greatest frequency of observed close proximity to cow and suckling in the first two weeks and decreased with experiment duration. During separation for milking, cow vocalizations and attempts to return to their calf decreased over time. Reticulorumen weight was on target for calf age, but as a proportion of total stomach weight was lower than industry averages of calves the same age due to the larger abomasum. Cows produced an average of 12±7.6 kg of milk yield per day over the 3-days before the calves were weaned and increased to mean of 31±8.3 kg/d the 3 days after weaning, indicating a consumption of close to 20 kg per calf per day. Conclusion: The impact of a pasture-based cow-calf rearing system on cow and calf behavior and the potential for high levels of calf liveweight gain when provided ad-libitum milk and feed were determined. Further research is required to determine the practicality of replicating such systems with large herds and impact on reared calves post-weaning.

• Korean Journal of Environmental Agriculture
• /
• v.42 no.4
• /
• pp.457-464
• /
• 2023

The rendering residue generated by rendering disposal, an eco-friendly livestock carcass disposal method, is a useful agricultural resource. Methods for recycling this are being actively researched, and this study investigated the impact of applying rendered residue directly to soil on crop productivity and the agricultural environment. The chemical properties of the rendering residue were examined. The pH, OM, T-N, T-P, CaO, K₂O, and MgO content values were 5.47%, 59.8%, 9.22%, 2.96%, 2.16%, 0.51% and 0.10%, respectively. Treatment conditions were divided into control, inorganic fertilizer, and rendering residue, and rendering residue corresponding to 50, 100, and 200% nitrogen content was applied based on the amount of inorganic fertilizer nitrogen input. Greenhouse gases and ammonia were collected during the cultivation period. Rendering residue increased both the yield and growth of peppers and was effective in improving nutrients such as pH and OM of the soil after harvest. However, compared to inorganic fertilizer treatment, it increased emissions of nitrous oxide and methane as well as ammonia. It is judged that the direct agricultural use of rendering residue is difficult, and a utilization method is needed.