• Journal of Animal Science and Technology
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• 제65권2호
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• pp.387-400
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• 2023

Ruminal protozoa, especially entodiniomorphs, engulf other members of the rumen microbiome in large numbers; and they release oligopeptides and amino acids, which can be fermented to ammonia and volatile fatty acids (VFAs) by amino acid-fermenting bacteria (AAFB). Studies using defaunated (protozoa-free) sheep have demonstrated that ruminal protozoa considerably increase intraruminal nitrogen recycling but decrease nitrogen utilization efficiency in ruminants. However, direct interactions between ruminal protozoa and AAFB have not been demonstrated because of their inability to establish axenic cultures of any ruminal protozoan. Thus, this study was performed to evaluate the interaction between Entodinium caudatum, which is the most predominant rumen ciliate species, and an AAFB consortium in terms of feed degradation and ammonia production along with the microbial population shift of select bacterial species (Prevotella ruminicola, Clostridium aminophilum, and Peptostreptococcus anaerobius). From an Ent. caudatum culture that had been maintained by daily feeding and transfers every 3 or 4 days, the bacteria and methanogens loosely associated with Ent. caudatum cells were removed by filtration and washing. An AAFB consortium was established by repeated transfers and enrichment with casamino acids as the sole substrate. The cultures of Ent. caudatum alone (Ec) and AAFB alone (AAFB) and the co-culture of Ent. caudatum and AAFB (Ec + AAFB) were set up in three replicates and incubated at 39℃ for 72 h. The digestibility of dry matter (DM) and fiber (NDF), VFA profiles, ammonia concentrations, pH, and microscopic counts of Ent. caudatum were compared among the three cultures. The co-culture of AAFB and Ent. caudatum enhanced DM degradation, VFA production, and Ent. caudatum cell counts; conversely, it decreased acetate: propionate ratio although the total bacterial abundance was similar between Ec and the Ec + AAFB co-culture after 24 h incubation. The ammonia production and relative abundance of C. aminophilum and P. anaerobius did not differ between AAFB alone and the Ec + AAFB co-culture. Our results indicate that Ent. caudatum and AAFB could have a mutualistic interaction that benefited each other, but their interactions were complex and might not increase ammoniagenesis. Further research should examine how such interactions affect the population dynamics of AAFB.

• Animal Bioscience
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• 제36권7호
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• pp.1067-1074
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• 2023

Objective: Better feed efficiency can be achieved by selecting rabbit genotypes with lower residual feed intake (RFI) under high ambient temperatures. Methods: Two genotypes of rabbits (Jabali, Saudi local breed and imported, Spanish V-line) were used to derive RFI and to investigate the relationship between RFI and productive traits. In total, 250 animals (125 each) were housed in individual wire mesh cages in a semi-closed rabbitry. Growth performance, feed criteria, carcass evaluation, biochemical blood analysis, and immune responses were determined. Results: Superiority in growth performance, feed efficiency, carcass characteristics, and cellular immunity was recorded in the Jabali breed compared to the V-line genotype. According to regression analysis, a significant effect of daily body weight gain was found, upon computing the expected feed intake in both genotypes. Moreover, mid-body weight^0.75 had a significant effect only in the Jabali breed. Positive correlation coefficients between RFI and dry matter feed intake or feed conversion ratio were found. The same trend in this relationship between RFI and productive traits was observed in some cases for both genotypes. An opposite trend in correlations was observed in the studied genotypes for some traits. Conclusion: The results suggest that the relationship between RFI and productive traits must be taken into consideration in rabbit breeding programs under the prevailing environment. However, further studies are required to investigate the effect of rabbit genotype and environmental factors on computing RFI.

• Animal Bioscience
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• 제36권8호
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• pp.1199-1208
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• 2023

Objective: The purpose of this study was to perform a comparative analysis of metabolite levels in serum and milk obtained from cows fed on different concentrate to forage feed ratios. Methods: Eight lactating Holstein cows were divided into two groups: a high forage ratio diet (HF; 80% Italian ryegrass and 20% concentrate of daily intake of dry matter) group and a high concentrate diet (HC; 20% Italian ryegrass and 80% concentrate) group. Blood was collected from the jugular vein, and milk was sampled using a milking machine. Metabolite levels in serum and milk were estimated using proton nuclear magnetic resonance and subjected to qualitative and quantitative analyses performed using Chenomx 8.4. For statistical analysis, Student's t-test and multivariate analysis were performed using Metaboanalyst 4.0. Results: In the principal component analysis, a clear distinction between the two groups regarding milk metabolites while serum metabolites were shown in similar. In serum, 95 metabolites were identified, and 13 metabolites (include leucine, lactulose, glucose, betaine, etc.) showed significant differences between the two groups. In milk, 122 metabolites were identified, and 20 metabolites (include urea, carnitine, acetate, butyrate, arabinitol, etc.) showed significant differences. Conclusion: Our results show that different concentrate to forage feed ratios impact the metabolite levels in the serum and milk of lactating Holstein cows. A higher number of metabolites in milk, including those associated with milk fat synthesis and the presence of Escherichia coli in the rumen, differed between the two groups compared to that in the serum. The results of this study provide a useful insight into the metabolites associated with different concentrate to forge feed ratios in cows and may aid in the search for potential biomarkers for subacute ruminal acidosis.

• 농업과학연구
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• 제48권4호
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• pp.965-973
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• 2021

The intention of this research is to analyze the effects of lactulose (LAC) supplementation on the growth performance, nutrient digestibility, microbial shedding, and fecal noxious gas emissions on weaning pigs in a 42-day trial. Based on the initial body weight and sex, a total of 255 piglets (21 day old) were randomly allocated into one of three dietary treatments with 15 replications and five pigs (two female and three male) per pen. The dietary treatments were as follows: a corn-soybean meal-based basal diet (CON) supplemented with 0, 1, and 2 g·kg^-1 of LAC. During phase 1, significant (p < 0.05) increases in the average daily feed intake and average daily gain (ADG) were observed, whereas during phase 2 and overall experimental period, significant improvements (p < 0.05) in the body weight, ADG, and gain to feed ratio were observed in pigs fed a graded level of LAC compared to those fed the CON diet. Additionally, dietary LAC supplementation significantly improved (p < 0.05) the nutrient digestibility dry matter, nitrogen, and gross energy in both phase 1 and phase 2. Moreover, the inclusion of LAC supplementation significantly increased (p < 0.05) the fecal Lactobacillus counts and reduced (p > 0.05) the E. coli counts in pigs. Furthermore, LAC supplementation reduced (p > 0.05) fecal ammonia and hydrogen sulfide gas emissions during phase 2. The results here indicate that the addition of lactulose at 1 g·kg^-1 and/or 2 g·kg^-1 would be optimal to improve the performance outcomes of weaning piglets.

• Journal of Animal Science and Technology
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• 제65권6호
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• pp.1270-1289
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• 2023

This study evaluates how different feeding systems impact ruminal fermentation, methane production, and microbiota of Hanwoo steers native to Korea. In a replicated 2 × 2 crossover design over 29 days per period, eight Hanwoo steers (507.1 ± 67.4 kg) were fed twice daily using a separate feeding (SF) system comprising separate concentrate mix and forage or total mixed rations (TMR) in a 15:85 ratio. The TMR-feeding group exhibited a considerable neutral detergent fiber digestibility increase than the SF group. However, ruminal fermentation parameters and methane production did not differ between two feeding strategies. In addition, TMR-fed steers expressed elevated Prevotellaceae family, Christensenellaceae R-7 group, and an unidentified Veillonellaceae family genus abundance in their rumen, whereas SF-fed steers were rich in the Rikenellaceae RC9 gut group, Erysipelotrichaceae UCG-004, and Succinivibrio. Through linear regression modeling, positive correlations were observed between the Shannon Diversity Index and the SF group's dry matter intake and methane production. Although feeding systems do not affect methane production, they can alter ruminal microbes. These results may guide future feeding system investigations or ruminal microbiota manipulations as a methane-mitigation practice examining different feed ingredients.

• Animal Bioscience
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• 제37권1호
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• pp.142-150
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• 2024

Objective: This study was conducted to assess effects of heat stress on growth performance, physiological parameters, and blood profiles of Hanwoo steers during early-fattening period in climate chambers. Methods: Four Hanwoo steers (body weight, 454.3±10.9 kg; age, 14±0.1 month) were allocated into four levels of temperature-humidity index (THI) in a 4×4 Latin square design for 21 days (pre-adaptation, 7 d; heat stress, 7 d; post-adaptation, 7 d) per period. Experimental treatments were assigned according to THI chart based on National Institute Animal Science (NIAS, 2022): Comfort (25.5℃ to 26.5℃, 60%; THI 73 to 75), Mild (28℃ to 29℃, 60%; THI 77 to 79), Moderate (29.5℃ to 30.5℃, 80%; THI 82 to 84), and Severe (31℃ to 32℃, 80%; THI 85 to 86) in separate climatic controlled chambers. Results: The dry matter intake (DMI) of the formula feed was lower in Severe compared to Mild and Comfort (p<0.05). The DMI of rice straw was the lowest in Severe and lower in Moderate than Comfort and Mild (p<0.05). Both average daily gain and feed conversion ratio of Severe and Moderate were lower than those of Mild and Comfort (p<0.05). Water intake was the highest in Severe and lower in Moderate compared with Comfort and Mild (p<0.05). Heart rate and rectal temperature increased as THI level increased (p<0.05). Glucose was the lowest in Severe and lower in Moderate compared to Comfort (p<0.05). On the contrary, non-esterified fatty acid was the highest in Severe and lower in Moderate compared with Comfort (p<0.05). Blood urea nitrogen of Moderate and Severe were higher than those of Comfort and Mild (p<0.05). Cortisol increased as THI increased (p<0.05). Conclusion: This study demonstrated the negative effects of heat stress on the performance and physiological responses of Hanwoo steers during the early-fattening period. In addition, it is judged that the THI chart for Hanwoo steers of National Institute of Animal Science (2022) was properly calculated.

• Journal of Animal Science and Technology
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• 제66권1호
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• pp.103-114
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• 2024

This study was done to investigate the effects of the incorporation of Achyranthes japonica extracts (AJE) in diet on the production parameters of growing pigs. Exp 1: Total, 105 crossbred pigs (average body weight: 24.47 ± 2.46 kg) were used in a 6-week feeding trial. Pigs (seven replicates, five pigs per pen) were allotted randomly to three treatments. Dietary treatments: CON (basal diet); basal diet with 0.025% AJE, and basal diet + 0.050% AJE). Growth performance, nutrient digestibility, fecal microbial count, and fecal noxious gas were assessed in this study. Average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F) were not affected by the addition of up to 0.05% AJE. In the case of apparent total tract digestibility (ATTD), dry matter (DM), nitrogen (N), and digestible energy (DE) were not changed in 3rd and 6th weeks of the feeding trial through the addition of AJE up to 0.05% in the growing pig diet. In microbial count, Lactobacillus and Escherichia coli count at 3rd and 6th week was similar in all the treatment diets. The inclusion of AJE at levels up to 0.05% in growing pig diet had no effect on the production of NH3, H2S, acetic acid, and CO₂ in the feces. After ending the Exp 1, a total of nine pigs were divided into three treatment groups. Treatment diets were included, TRT1, basal diet + powder quercetin 30 g; TRT2, basal diet + powder quercetin 150 g; TRT3, basal diet + powder quercetin 300g. Rate of absorption in blood was increased with the higher dose of quercetin. The results suggested incorporation of AJE up to 0.05% has no significant effect on ADG, ADFI, and G:F, as well as DM, N, and DE digestibility, fecal microbial count, and fecal noxious gas emission in growing pigs, even though no negative effect was found.

• Animal Bioscience
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• 제37권6호
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• pp.1130-1139
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• 2024

Objective: The daily maximum temperature and seawater level continuously increase as global warming continues. We examined the adaptability and production performance of heat-stressed goats with a supply of low-saline drinking water. Methods: Twelve Kacang and Kacang Etawah cross goats were exposed to two climatic conditions (control, 25℃ to 33℃, 83% relative humidity [RH], temperature humidity index [THI]: 76 to 86; and hot environment, 26℃ to 39℃, 81% RH, THI: 77 to 94) and two salt levels in drinking water (0% and 0.4% NaCl). The experimental design was a Latin Square (4×4) with four treatments and four periods (28 days each). Results: Temperature of the rectal, skin, and udder, and respiration rate rose, reached a maximum level on the first day of heat exposures, and then recovered. Plasma sodium rose at 0.4% NaCl level, while the hot environment and salinity treatments increased the drinking water to dry matter (DM) intake ratio. Water excretion was elevated in the hot environment but lowered by the increase in salinity. Total lying time increased, whereas change position frequency decreased in the hot condition. Lying and ruminating and total ruminating time increased and explained the enhanced DM digestibility in the hot conditions. Conclusion: The goats exhibited a high level of plasma sodium as salinity increased, and they demonstrated physiological and behavioral alterations while maintaining their production performances under increasing daily maximum temperatures.

• Journal of Animal Science and Technology
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• 제47권6호
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• pp.955-962
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• 2005

본 시험은 두충 잎을 저질 조사료인 볏짚의 일부로 대체․이용할 목적으로 평균체중 50.2 $\pm$1.6kg의 건강한 숫 면양(Corriedale$\time$Polwarth) 4두로 4$\time$4 라틴 방각법으로 실시하였으며, 이때 농후사료 : 조사료의 비율은 3：7이었다. 시험구는 두충을 대체하지 않은 대조구와 조사료인 볏짚의 건물을 기준으로 음건 두충 잎을 3, 5 및 10% 대체한 4개 처리구를 공시하였으며, 영양소 이용율, 기호성, 반추위 내 발효 특성 및 미생물체단백질 합성량을 조사․분석하였다. 조지방 소화율은 3% 구와 5% 구가 대조구에 비하여 약 12.5-17.5%로 증가하였다(p<0.05). 조섬유 소화율은 두충잎을 대체한 모든 처리구가 대조구에 비하여 약 10.6-13.7%로 개선되었다(p<0.05). 건물 섭취량은 10% 구가 844g으로 가장 많았으며 5% 구는 그 다음으로 많이 섭취하였으며, 대조구와 3% 구는 가장 낮았다(p<0.05). 질소 축적량은 3% 구가 대조구에 비하여 약 97%가 개선되었으며, 5% 구와 10% 구가 약 173-192%가 개선되었다(p<0.05). 유기물 이용율은 3% 구와 5% 구가 대조구에 비해 높았다(p<0.05). PD(purine derivatives) 배설량은 5% 구가 2.90mmol/d로 대조구와 3% 구에 비하여 높았다(p<0.05). 미생물체단백질 합성량은 5% 구가 2.51gN/d로 대조구와 3% 구에 비하여 높았다(p<0.05). 반추위내 total VFA 함량은 두충 잎 처리구에서 높게 나타났다. RAN 함량은 두충 잎 급여 후 1-4시간에 15-19mg/100ml로 높게 유지되었다. 이상의 결과를 종합하면, 두충 잎을 음건하여 반추동물에게 5-10%를 대체하여 급여할 경우 영양소 소화율, 기호성 및 반추위 내 발효조건 개선에 유리할 것으로 생각된다.

• 한국초지조사료학회지
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• 제22권2호
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• pp.115-122
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• 2002

본 시험은 알팔파 건초의 혼합비율을 60%(A), 50%(B), 40%(C) 및 30%(D)의 4가지로 달리하여 조제한 시험사료를 이유 후 한국 재래산양에게 급여하여 사료 섭취량과 소화율 및 증체에 미치는 영향을 조사하여 이유 후 초기 사료 개발을 위한 기초자료로서 활용하고자 본시험을 실시하였으며, 그 결과를 요약하면 다음과 같다. 시험사료의 화학적 조성분은 조단백질 함량을 모두 18%로 고정시켜 동일하였으며 ADF, NDF 및 조회분의 함량은 A구가 각각 26.1, 37.0 및 9.0%로 가장 높았고 D구가 20.3, 30.4, 6.6%로 가장 낮았으나 비구조적 탄수화물(NSC) 함량은 반대의 경향을 나타내었다. 1일 두당 건물 섭취량은 A와 B구가 각각 414.4와 417.7g으로 가장 높았고 D구가 362.6g으로 유의하게 낮았다(p<0.05). 대사체중 당 건물섭취량(DM g/kg of $BW^{0.75}$)은 A구가 73.9g으로 가장 높았고, D구가 64.0g으로 가장 낮았다. 일당 증체량과 사료 효율은 각각 33.3~48.7g과 8.1~13.4%의 범위로 처리간 유의차는 인정되지 않았지만 조사료 혼합비율이 낮을수록 높았다. 재래산양에 의한 건물, 유기물, 조단백질, ADF, NDF, 조회분 및 NSC의 소화율은 농후사료 함량이 높은 처리구일수록 높고 조사료 함량이 높은 처리구일수록 낮은 경향을 보였다. 재래산양에 있어 서의 질소축적량과 질소축적율은 A구가 각각 1.8g과 15.5%로 가장 낮았고 D구가 각각 2.7g과 25.7%로 가장 낮았다. 이상의 결과를 종합하여 볼 때 어린 재래산 양의 초기사료로서 알팔파 건초를 조사료원으로 할 때 30~40%의 알팔파 건초의 혼합비율이 그 이상의 경우보다 산양의 일당 증체량 및 사료효율이 우수하였으며 이 때 사료내 조단백질 함량을 18%로 유지하는 것이 이유 후 어린 재래산양의 성장에 효과적이었다.