• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.94-102
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• 1991

This study was directed to further clarify the effect of resting time or dietary condition for the improvement of exercise capacity and physical fitness, and the changes of some body consitiuents and physiological functions which are related to the exercise metabolism. Sixteen male students(8 athletes and 8 nonathletes)were participated during 3 weeks(Aug. 20-Sep.9, 1989). Each subject performed two treadmill running trials at an absolute intensity (1 mintute in 3.4mph/15% slope and 2 minutes in 5.5mph/20% slope). In the resting time trials, general diet was fed before 1, 2, 4 and 12 hours of the treadmill exercise loaded. in the dietary condition trials, high carbohydrate(HC), high fat(HF) and high protein(HP) diet were fed before 2 hours of the treadmill exercise loaded. Control trial was that of resting time before treadmill exercise loaded after 12 hours of general diet feeding. Measurement were made to study the change of blood glucose, palmitate, lactate, blood pressure and heart rate. The results obtained are summarized as follows: Mean daily metabolizable period. In resting time trial, the blood glucose concentration of athlete and nonathlete from 2 hours group was similar to control group. The blood palmitate concentration of athlete was increased in 1 and 2 hours group but those of nonathlete was not only increased in 1 and2 hours group but was more increased in 12 hours group, compared with both control group. The blood lactate concentration was increased in all experimental group, compared with both control group and those of nonathlete was much higher than athlets. The elevation rate of blood pressure in pre-and after-exercise of athlete was lower than those of nonathlete. In dietary composition trial, the blood glucose concentration of athlete and nonathlete in HC group was higher than other diet groups. The blood lactate concentration of athlete and nonathlete in HC group was lower than other diet groups. There was no remarkable change of the blood palmitate concentration and heart rate in each dietary composition trial, but those of nonathlete was low in HC and high in HP group. In above results, it was suggested that the effective condition of resting time and dietary composition for the improvement of exercise capacity of nonathlete may be 2 hours and HC diet, respectively. But it was showed that the exercise capacity of athlete may not be affected by experimental condition of resting time, except 1 hour after feeding or of dietary composition because of well adaptation in new exercise condition.

• Animal Bioscience
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• v.35 no.5
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• pp.690-697
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• 2022

Objective: This study aimed to evaluate the effect of the ad libitum and restricted feeding regimen on fasting heat production (FHP) and body composition. Methods: Twelve Hubbard broilers breeders were selected with the same body weight and submitted in two feeding regimes: Restricted (T1) with feed intake of 150 g/bird/d and ad libitum (T2). The birds were randomly distributed on the treatments in two runs with three replications per treatment (per run). The birds were adapted to the feed regimens for ten days. After that, they were allocated in the open-circuit chambers and kept for three days for adaptation. On the last day, oxygen consumption (VO₂) and carbon dioxide production (VCO₂) were measured by 30 h under fasting. The respiratory quotient (RQ) was calculated as the VCO₂/VO₂ ratio, and the heat production (HP) was obtained using the Brower equation (1985). The FHP was estimated throughout the plateau of HP 12 hours after the feed deprivation. The body composition was analyzed by dual-energy X-ray absorptiometry scanning at the end of each period. Data were analyzed for one-way analysis of variance using the Minitab software. Results: The daily feed intake was 30 g higher to T2 (p<0.01) than the T1. Also, the birds of the T2 had significatively (p<0.05) more oxygen consumption (+3.1 L/kg^0.75/d) and CO₂ production (+2.2 L/kg^0.75/d). That resulted in a higher FHP 359±14 kJ/kg^0.75/d for T2 than T1 296±17.23 kJ/kg^0.75/d. In contrast, the RQ was not different between treatments, with an average of 0.77 for the fasting condition. In addition, protein and fat composition were not affected by the treatment, while a tendency (p<0.1) was shown to higher bone mineral content on the T1. Conclusion: The birds under ad libitum feeding had a higher maintenance energy requirement but their body composition was not affected compared to restricted feeding.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1225-1233
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• 2009

Fat composition of beef, taken here to mean marbling, can be manipulated by time on feed, finishing diet, and breed type. These three factors also strongly influence the fatty acid composition of beef. Both the amount of marbling and the concentration of monounsaturated fatty acids (MUFA) increase with time on feed in grain-fed and pasture-fed cattle, but much more dramatically in grain-fed cattle. High-concentrate diets stimulate the activity of adipose tissue stearoyl-CoA desaturase (SCD), which is responsible for the conversion of saturated fatty acids (SFA) to their $\Delta{9}$ desaturated counterparts. Also, grain feeding causes a depression in ruminal pH, which decreases those populations of ruminal microorganisms responsible for the isomerization and hydrogenation of polyunsaturated fatty acids (PUFA). The net result of elevated SCD activity in marbling adipose tissue and depressed ruminal isomerization/hydrogenation of dietary PUFA is a large increase in MUFA in beef over time. Conversely, pasture depresses both the accumulation of marbling and SCD activity, so that even though pasture feeding increases the relative concentration of PUFA in beef, it also increases SFA at the expense of MUFA. Wagyu and Hanwoo cattle accumulate large amounts of marbling and MUFA, and Wagyu cattle appear to be less sensitive to the effects of pastures in depressing overall rates of adipogenesis and the synthesis of MUFA in adipose tissues. There are small differences in fatty acid composition of beef from Bos indicus and Bos taurus cattle, but diet and time on feed are much more important determinants of beef fat content and fatty acid composition than breed type.

• Journal of Animal Science and Technology
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• v.51 no.6
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• pp.537-542
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• 2009

For a period of over 6 years, more than 160,000 milk samples were collected and analyzed to determine the influence of different seasonal temperatures and geographic regional location on milk composition in South Korea. Fat, protein, lactose, non fat milk solids (NFMS) and total solids (TS) contents were significantly higher among dairy cows milked in winter season than other seasons (p<0.05). In contrast, freezing point (FP), milk urea nitrogen (MUN) and somatic cell count (SCC) were significantly higher in summer season than other seasons (p<0.05). The average SCC in the autumn season was $358{\times}10^3$/ml, which was lower than any other seasons (p<0.05). These results may be due to the changes in temperature during different seasons. Meanwhile, milk produced by dairy cows in central region had higher fat, protein, lactose, NFMS, TS and MUN and had lower SCC compared to other regions (p<0.05). Fat, TS, FP, MUN and citric acid in northeast region were lower than other regions (p<0.05). The SCC was significantly higher in southeast region than those of other regions (p<0.05). As a result, it might be possible that the differences in feeding management in each different region may affect the milk composition. In conclusion, present results indicated that milk composition is clearly influenced by both season and regional location. Therefore, based on these results, development of different feeding systems, according to season and region is needed to produce high quality and satiable milk production.

• Asian-Australasian Journal of Animal Sciences
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• v.7 no.4
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• pp.493-498
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• 1994

The response of crossbred Holstein milking cows to the neutralized urea-treated rice straw feeding was investigated. Rice straw was treated with 6% urea for at least 21 days and further with sulfuric acid for overnight to complete the neutralization. The neutralized straw was then sun-dried and its feeding value was compared with that of the dried non-neutralized urea-treated straw. They were fed to the cows with concentrates either by the ration formulation based on the nutrient requirements for milk production recommended by NRC or by the traditional way in which straw was fed ad libitum and concentrates at 1 kg/2 kg of milk production. The results showed that milk production as well as milk composition of cows were not different between neutralized and non-neutralized straw. The feeding of the neutralized straw could significantly reduce the supply of protein-rich feed such as soybean oil meal, and it was demonstrated that ammonium sulfate in the neutralized straw could be utilized as effective as the plant origin protein. The results also suggested that if the traditional feeding method is applied to the dairy cattle, protein content of the supplementing concentrates should be increased to meet the requirement.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.498-506
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• 2015

We examined the feeding habits of larval Clupea pallasii using 148 specimens collected from December 2010 to April 2011 in the Nakdong River estuary, Korea. We found that larval C. pallasii [8.3-26.0 mm NL (notochord length)] are carnivorous, consuming mainly copepods, rotifers, cirripeds, and free-living flatworms (Macrostomida). Their diet also include small quantities of shrimp nauplii, tintinnids, cladocerans, and larval bivalves, among other food sources. To evaluate ontogenetic changes in dietary composition, we split larvae into four size groups: 8-12 mm, 12-16 mm, 16-20 mm, and > 20 mm NL. Rotifers were the most important prey items for the smallest group, but all other groups predominantly consumed copepods. The largest group frequently preyed on rotifers, cirripeds and flatworms, in addition to copepods. Larvae also showed bi-modal feeding, with peaks in the late afternoon and at midnight, wherein the mean number of prey per individual peaked at 1,800-1,900 h.

• Journal of Aquaculture
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• v.20 no.2
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• pp.90-95
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• 2007

Artificially-produced juvenile black sea bream, Acanthopagrus schlegeli (total length $10.4{\pm}1.1\;cm$, body weight $18.7{\pm}3.4\;g$) were released into the Gamak Bay in Korea. And their initial feeding habits and body compositions were compared with those of cultured fish (CUL) for a period of one month after release. The released black sea bream commenced feeding on the 1st day after release, and predation rate was more than 80% during the sampling period. The stomach content of fish was composed of mainly fishing bait and krill in fish sampled on 15th days after release; however, its content changed to the natural organisms such as algae and small crustaceans when the fish was sampled on 20th days after release. Crude lipid content of carcass of fish in the sampling station A (SA) were lower than that of fish in the initial, sampling station B (SB) and CUL for the 5th and 10th days after release. Carcass n-3 HUFA composition, total amino acid and essential amino acid contents of released fish showed high trend compared to that of cultured fish in 30th days after release. The released fish have the ability to adjust their feeding habits and biochemical metabolism to the natural environment within a short period even though they showed preference to artificial feed in the early days after release.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1475-1481
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• 2002

The study was conducted to evaluate the effect of early feed restriction on growth, fat accumulation and meat composition in unsexed broiler chickens. In experiment 1, three hundred and fifty one-day-old broiler chicks were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chicks at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, five hundred broiler chicks were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three initial age at which broilers were restricted (2, 4 or 6 days of age) and three type of feed restriction (physical restriction, meal feeding and diet dilution) ($3{\times}3$) were examined. They were restricted feeding for 6 days. Experimental results showed that broilers fed 25% ad libitum for 4-6 days tended to reduce leg meat fat with lower abdominal fat (p<0.05) (experiment 1). Breast meat fat was significantly higher in restricted broilers (p<0.01). Plasma triglyceride was higher in broilers fed 75% ad libitum for 4-6 days. In experiment 2, abdominal fat was lower in restricted broilers (p<0.05). Breast meat fat was significantly higher (p<0.01), whereas leg meat fat was significantly lower (p<0.05) in restricted broilers. Plasma triglyceride was significantly higher in physical feed restriction for 4 days, meal feeding for 4 days and diet dilution for 6 days (p<0.05). In conclusion, to reduce fat accumulation in abdomen and leg meat, broilers should be fed 25% ad libitum for 6 days started at 4 days, or subjected to meal feeding (6 hours per day for 6 days) started at 6 days.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.5
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• pp.490-495
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• 1992

The effects of high levels of vitamin E and cholesterol feeding on the lipid composition of the plasma lipoproteins were tested between 4 experimental groups. The concentrations of vitamin E and cholesterol in the plasma lipoproteins were significantly increased with the feedings. But the concentrations of cholesterol and various lipid fractions showed significant low levels on the vitamin E feeding group, which vitamin E was fed after the cholesterol diet. Vitamin E showed the hypocholesterolemic effect when it was fed after the high cholesterol containing diet. But, vitamin E was less effective to decrease the content of cholesterol on the diet which contained the both vitamin E and 2% cholesterol. It also showed that vitamin E could stimulate the absorption of cholesterol and lipid when the both dietary factors were simultaneously fed. The vitamin E feeding also resulted in increase of the cholesterol concentration in HDL/LDL ratios.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1433-1442
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• 2021

In this study, Saccharomyces cerevisiae culture fluid (SCCF) has been added to a diet of lactating dairy cows to attempt to improve the ruminal fermentation and potentially increase the dry matter intake (DMI) and milk yield. This study was conducted to investigate the effects of SCCF on the milk yield and blood biochemistry in lactating cows during the summer. Twenty-four Holstein dairy cows were randomly assigned to one of four treatments: (1) total mixed ration (TMR-1) (Control); (2) TMR-1 supplemented with SCCF (T1); (3) TMR-2 (containing alfalfa hay) (T2); and (4) TMR-2 supplemented with SCCF (T3). SCCF (5 ml/head, 2.0×10⁷ CFU/mL) was mixed with TMRs daily before feeding to dairy cows. The mean daily temperature-humidity index (THI) during this trial was 76.92 ± 0.51 on average and ranged from 73.04 to 81.19. For particle size distribution, TMR-2 had a lower >19 mm fraction and a higher 8-9 mm fraction than TMR-1 (p < 0.05). The type of TMR did not influence the DMI, body weight (BW), milk yield and composition, or blood metabolites. The milk yield and composition were not affected by the SCCF supplementation, but somatic cell counts were reduced by feeding SCCF (p < 0.05). Feeding SCCF significantly increased the DMI but did not affect the milk yield of dairy cows. The NEFA concentration was slightly decreased compared to that in the control and T2 groups without SCCF. Feeding a yeast culture of S. cerevisiae may improve the feed intake, milk quality and energy balance of dairy cows under heat stress.