Effects of feeding system on growth performance, plasma Biochemical components and hormones, and carcass Characteristics in Hanwoo steers.
To maximize productivity and carcass traits of beef cattle, it is common practice to provide a high amount of formulated concentrate diet in the feeding systems of many countries. However, over the last decade, feed costs of beef cattle have increased by 70% to 80% mostly due to increasing grain prices. Accordingly, there is increasing demand for low-cost alternative feedstuff's in livestock operations. This has focused attention on a total mixed ration (TMR) for beef production, which contains agricultural by-products, several grains and functional herbs as sources of feed ingredients [1,2]. As a consequence of the attempt to lower production costs, beef producing farmers have increased using a TMR in recent years, although this method has been criticized for its quality of diet such as inconsistent feed ingredients, a lower nutrient value and contamination by harmful microbes and residues, etc.
Nevertheless, using a TMR feeding system in beef production provides advantages with precision, efficiency and convenience that may improve overall on-farm level of productivity . Several studies with steers have been conducted to assess the effects of a TMR on ruminal fermentation, animal performance, carcass quality, economic analyses, etc. [4,5]. Martin et al  reported that there was a significant difference in carcass fat score and intramuscular fatty acid compositions in cattle fed a high concentrate diet plus straw and a TMR contained cereal, soybean meal, corn silage and straw, although weight at slaughter was not different between two dietary feeding systems. However, Cortes et al  reported that carcass quality and composition of beef heifers fed a TMR were not significantly different from these fed a commercial concentrate (93%) and straw (7%). There is still a lack of published information on the effects of feeding system on beef performance and carcass traits because of the inherent complexity of feed ingredients and energy density, feeding duration, management practices, the effect of environmental conditions, etc. [8,9].
Thus, we applied two different feeding systems (CON vs TMR) in beef production to evaluate the effects of feeding system on growth performance, serum biochemical profiles, and carcass traits in Hanwoo steers.
MATERIALS AND METHODS
Experimental animals and design
Sixty Hanwoo steers aged 8 month (initial mean body weight [BW] 224[+ or -]3.88 kg, housed in 5 calves per pen) were weighed individually and randomly assigned to two different feeding system (CON vs TMR). Twenty steers were assigned to the formulated concentrate with rice straw separately (CON, n = 4, 5 head per pen), and forty steers were assigned to the TMR group (n = 8, 5 head per pen). Ingredient composition of experimental diets is presented in Table 1. Steers of the CON group fed a concentrate during each period (4 to 7 kg/d in growing period, 7 to 9 kg/d in fattening period, ad libitum in finishing period) with rice straw (ad libitum in growing period, 2 kg/d in fattening period, 1 kg/d in finishing period). Steers of TMR group were freely fed a TMR during each period for whole experimental period. The entire feeding period (8 to 30 month of age) was divided into growing (8 to 12 month), fattening (13 to 23 month), and finishing periods (24 to 30 month). All steers were allowed free access to feed, water and mineral blocks. Steers were daily given the corresponding experimental diet throughout the experiment period according to dietary feeding program, and fed same amounts of dry matter intake through the whole experimental period.
The pen (5 mx10 m) was installed with feeder, which allowed the animals free access to any part of the pen. Steers were weighed every 4 weeks with feed intake and average daily intake (ADG) for the entire feeding periods. The animal handling procedures in the present study followed the guidelines of the institutional animal care and use committee.
Analysis of chemical composition
The chemical composition of feeds including crude protein, ether extract, crude fiber, and crude ash was measured according to the guidelines of (Table 2). Neutral detergent fiber and acid detergent fiber were analyzed by the method of. All samples were performed in duplicate. Total digestible nutrient (TDN) in concentrate was obtained from the feed company based on their calculation.
Blood sampling and analysis of biochemical components and hormones
At the end of growing, fattening and finishing periods, blood samples (20 mL) were taken from the jugular veins of steers using syringe and then transferring the blood into heparin coated sterile vacutainer (Becton Dickinson, NJ, USA) wrapped with foil. Next, plasma was harvested by centrifugation (3,000 rpm, 20 min). All harvested plasma was rapidly frozen and stored at -70[degrees]C until further assay.
Blood biochemical components including aspartic acid transaminase (AST), alanine transaminase, blood urea nitrogen (BUN), glucose, total protein, albumin, cholesterol, and triglyceride were analyzed with the Automatic Biochemical Analyzer (HI System, Technicon, Tarrytown, NY, USA).
Plasma insulin and leptin were assayed by enzyme-immuno assay using Multi-species Insulin RIA kit and Multi-species Leptin RIA kit (Linco Research, Inc, St. Charles, MO, USA), respectively. I125 radioactivity was monitored using y-counter (COBRATM II, Packard Bioscience, Downers Grove, IL, USA).
Analysis of plasma retinol by high-performance liquid chromatography
High-performance liquid chromatography (HPLC, Perkin-Elmer, Series 200, Waltham, MA, USA) was used for the analysis of retinol in the plasma of Hanwoo steers according to the methods of The Vitamin Society of Japan . In brief, the plasma (50 [micro]L) were placed into brown centrifuge tubes containing 50 [micro]L of ethanol and tubes were vortexed for 10 seconds. Next, 300 [micro]L of n-hexane were added into tubes and vortexed for 60 seconds. These tubes were then centrifuged at 3,000 rpm for 5 min to isolate the supernatant of the n-hexane layer extract (250 [micro]L). After that, 300 [micro]L of n-hexane was added to the remaining n-hexane layer and re-centrifuged at 3,000 rpm for 5 min to isolate the supernatant of the n-hexane layer (250 [micro]L). The harvested supernatant of the extract was evaporated under [N.sub.2] injection and the residue was dissolved into 50 [micro]L iso-propanol for HPLC analysis. For the quantification of retinol, an aliquot was injected into the HPLC system with Brownlee Validated C-18 column (5 pm, 4.6 mmx150 mm). A calibration curve was prepared using retinol standard (Sigma-Aldrich, St. Louise, MO, USA).
Carcass trait assessment
After feeding trial, all steers were fasted for 24 h and slaughtered at a commercial meat abattoir to assess carcass yield and quality. Carcasses were chilled for 24 h at 4[degrees]C, after which the left sides were opened between the 13th rib and the 1st lumbar and the longissimus dorsi was then used for grading yield and quality of carcass according to the standard criteria guided by . Cold carcass weight, back-fat thickness, and size of loin-eye were evaluated for the determination of yield grade index, and yield grade ranged from 1 to 3. Marbling score (1 to 9), fat color (1 to 9), meat color (1 to 9), texture (1 to 3), and maturity (1 to 9) were evaluated for the assessment of carcass quality, and quality grade was ranged from 1 to 5.
The effects of two different feeding system on BW, ADG, feed intake, blood biochemical components and hormones, and carcass traits were analyzed by PROC t-test . The correlation coefficients between blood parameters in fattening and finishing phases and carcass traits were analyzed by Pearson's methods. The level of probability for statistical difference was established at p<0.05. Data are presented as means[+ or -]standard error.
Dry matter and total digestible nutrient intakes, and growth performance
The dry matter (DM) and TDN intakes, and growth performance of Hanwoo steers in the two different feeding systems are presented in Table 3. Average DM and TDN intakes during whole experimental period were not significant different between the treatments. But there were significant (p<0.05) differences in DM intake during the finishing period, and in TDN intake during growing and fattening periods between the treatments. The BW of the CON group was significantly (p<0.05) heavier during finishing period compared to the TMR group, while there was no difference in BW during growing and fattening periods. Daily body gain was also significantly (p<0.05) higher in the CON group than the TMR group during fattening and finishing periods. Overall daily body gain during the entire period was also significantly higher (p<0.05) in the CON group. But feed conversion ratio did not appear to be statistically different between the two feeding system.
Blood biochemical components, retinol, leptin, and insulin
Data on blood biochemical profiles and the levels of retinol, leptin and insulin of Hanwoo steers by different feeding system are shown in Table 4, 5, respectively. The CON group had significantly (p<0.05) lower AST and BUN level during growing period, and higher cholesterol and triglyceride levels during fattening and finishing periods compared to the TMR group (Table 4). Blood retinol concentration in the TMR group was significantly (p<0.05) higher for growing period, and inclined to sustain a higher level for fattening and finishing periods compared to the CON group. Blood insulin and leptin levels were not affected by feeding system (Table 5).
Carcass traits and the correlations between blood components and carcass traits
Carcass yield and quality traits of Hanwoo steers by different feeding system are shown in Table 6. Cold carcass weight, back fat thickness and meat yield index and grade were also not affected by feeding system. However, rib-eye area of longissimus dorsi in the CON group was greater (p<0.05) than that of the TMR group. In carcass quality traits, marbling score index, one important meat quality, tended to be higher (p = 0.098) in the CON group compared to the TMR group, but there was no significant difference in meat quality grade between two groups except for meat color. Meat color was darker (p<0.05) red in the TMR group compared to the CON group.
The correlation coefficients between blood biochemical components and carcass traits in Hanwoo steers are presented in Table 7. Retinol had a significantly (p<0.05) negative correlation with marbling score and rib-eye area. Leptin showed a significantly (p<0.05) positive correlation with back fat thickness, whereas it had a negative correlation with carcass yield index. Glucose was negatively correlated with back fat thickness, while cholesterol and triglyceride appeared to have a significantly (p<0.05) positive correlation with carcass weight and rib-eye area.
In comparison of feeding systems (CON vs TMR) in beef cattle production, there are complicated practical difficulties including nutrient composition, feed ingredients, energy density, etc. in designing an experiment. There are several studies showing that feeding system did not affect growth performance and carcass traits [3,15], but there are also studies demonstrating that TMR feeding system improved animal performance and carcass traits [4,5,16]. In agreement with the report of , the present study demonstrated that the steers fed the higher proportion of concentrates in finishing periods had an increased DM intake compared with those fed a TMR. Caplis et al  also concluded that feeding method (concentrate and straw vs TMR) did not affect any of the growth performance parameters, suggesting that dietary energy value and dry matter intake are more important factors to increase growth performance rather than type of feeding system. It is evident that dietary energy level in finishing steers plays a crucial role in the production of high quality beef rather than feeding method [7,13]. Martin et al  also reported that weight at slaughter was not different in steers fed high concentrate diet compared with those fed a TMR. By contrast, Cooke et al  observed that TMR feeding increased feed intake, weight gain and carcass weight compared with separate feeding. From our study, it was concluded that feeding CON diet had advantages over a TMR especially during finishing period in beef production. This advantage might be attributed to increased DM intake during finishing periods in the CON group compared to the TMR group.
With the biochemical parameters in blood, steers fed concentrate and roughage separately showed a more desirable plasma biochemical profile including lower AST and BUN during growing period. While the steers of CON group showed higher levels of cholesterol and triglyceride during finishing period, which might be associated with the increased marbling score in the CON group compared to the TMR group. In general, it is known that increased circulating blood triglyceride is derived from the mobilization of the deposited fat content . In agreement with the present study, Kim et al  demonstrated that blood cholesterol concentration was positively correlated with BW of Hanwoo steers.
Blood retinol level in the steers of CON group was a significantly lower than that in the TMR group during growing period. This result might be due to lower [beta]-carotene concentration in concentrates with straw than in a TMR containing forages . Recent studies have demonstrated that depletion of retinol in the diet of beef cattle increased intramuscular fat and subsequently improved the quality of meat [20,21]. Leptin, a hormone secreted by adipocytes and recognized as a biomarker of body fat deposition, has been shown to increase when animal had a higher fat deposition [22,23]. Geary et al  reported that serum leptin level was significantly related to marbling score and back fat deposition in beef cattle, indicating that serum leptin may be a good indicator of body fat content in beef cattle. However, Yonekura et al  reported that serum leptin level in Japanese black cattle was not significantly associated with the marbling score of the longissimus dorsi. The level of blood insulin typically increases in well-fed and concentrate-fed cattle than in fastedand forage-fed cattle [25,26]. In the present study, we did not see any statistical difference in insulin and leptin levels between two feeding systems, reflecting that blood leptin and insulin levels were not directly affected by the feeding system in Hanwoo steers.
In carcass yield traits, most indicators including carcass weight, yield grade, and back fat thickness except rib-eye area were not affected by dietary feeding system. However, rib-eye area in the longissimus dorsi of the CON group was greater than that of the TMR group.
In carcass quality traits, meat color score was significantly lower in the steers fed concentrates with straw than those fed a TMR without affecting the other carcass quality indicators between two groups. In general, the present study is similar to a study of , who reported that carcass traits were not differ between finishing steers fed a TMR and those self-fed rations consisted of corn, wheat and barley with free-choice grass hay. Several studies also reported that feeding system itself did not influence carcass traits in steers [8,21,27]. However, not all studies have reported that feeding system did not affect carcass traits in beef cattle. In particular, it is widely accepted that meat color is much lighter in concentrates-fed beef cattle than in forage-fed cattle . This is also in agreement with our observation that the steers fed concentrate with rice straw showed a lower meat color compare with those fed a TMR containing higher level of forage. Consistent with the present data, Caplis et al  reported that steers fed silage had less bright and darker red muscle color than those fed concentrates. This difference may be attributed to higher carotene level of the forage in TMR. According to the reports of , carotenoid content was measured at 30 mg and 2 mg/kg DM for the TMR and high concentrate, respectively, although there are complicating factors in comparison of a TMR with concentrate diet. It seemed that the response of carcass traits to feeding method in beef steers could be differently affected, mostly depending upon the sort and percentage of feed ingredients, the level of forage, the density of energy level, etc. .
In summary, the feeding system of CON compared to the TMR system may give more desirable growth performance and carcass traits in Hanwoo steers under the circumstances of the present study. However, it is still required to explore the effects of feeding system on beef production under the various conditions of feeding and management. Through correlating data between the blood biochemical compositions during the fattening and finishing phase in Hanwoo steers and subsequent carcass traits, it may be possible to find a biomarker for beef quality prior to slaughter.
CONFLICT OF INTEREST
We certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript.
This work was supported by IPET (No. 315022-3) grant and the 2016 fund of Gyeongnam National University of Science & Technology in Korea.
[1.] Jeong CD, Mamuad LL, Ko JY, et al Rumen fermentation and performance of Hanwoo steers fed total mixed ration with Korean rice wine residue. J Anim Sci Technol 2016;58:4.
[2.] Lee SJ, Kim DH, Guan LL, et al Effect of medicinal plant by-products supplementation to total mixed ration on growth performance, carcass characteristics and economic efficacy in the late fattening period of Hanwoo steers. Asian-Australas J Anim Sci 2015;28:1729-35.
[3.] Moya D, Holtshausen L, Marti S, et al. Feeding behavior and ruminal pH of corn silage, barley grain, and corn dried distillers' grain offered in a total mixed ration or in a free-choice diet to beef cattle. J Anim Sci 2014;92:3526-36.
[4.] Cooke DWI, Monahan FJ, Brophy PO, Boland MP. Comparison of concentrates or concentrates plus forages in a total mixed ration or discrete ingredient format: effects on beef production parameters and on beef composition, colour, texture and fatty acid profile. Irish J Agric Food Res 2004;201-16.
[5.] Kim SH, Alam MJ, Gu MJ, et al. Effect of Total mixed ration with fermented feed on ruminal in vitro fermentation, growth performance and blood characteristics of Hanwoo steers. Asian-Australas J Anim Sci 2012;25:213-23.
[6.] Marin AM, Blanco FP, Ramirez CA, Alba LP, Polo OP. Selecting the best set of gas chromatography-derived fatty acids to discriminate between two finishing diets using linear discriminant analysis. Meat Sci 2013;95:173-6.
[7.] Cortes X, Mora J, Oliva P, et al. Comparison of two beef fattening diets: concentrate and straw vs. total mixed ration. XV Jornadas sobre Produccion Animal, Zaragoza 14 y 15 de mayo de 2013. pp. 61-3.
[8.] Caplis J, Keane MG, Moloney AP, O'Mara FP Effects of supplementary concentrate level with grass silage, and separate or total mixed ration feeding, on performance and carcass traits of finishing steers. Irish J Agric Food Res 2005;44:27-43.
[9.] Marti S, Perez M, Aris A, Bach A, Devant M. Effect of dietary energy density and meal size on growth performance, eating pattern, and carcass and meat quality in Holstein steers fed high-concentrate diets. J Anim Sci 2014;92:3515-25.
[10.] AOAC. Official methods of analysis of the AOAC International. 17th edn. Gaithersberg, MD: AOAC International; 2000.
[11.] Goering HK, Van Soest PJ. Forage fiber analysis (apparatus, reagents, procedures and some applications). Washington, DC, USA: USDA Agricultural Handbook No. 379, 1970. p. 1-20.
[12.] The vitamin analysis: The vitamin society of Japan; 1989. p. 3-18.
[13.] Korea Institute for Animal Products Quality Evaluation. Grading of carcass of methods, standard and enforcement, 2009.
[14.] SAS Institute. SAS/STAT user's guide, version 8: Cary, NC: SAS Institute; 1999.
[15.] Kreft B, Cargo R, Kreft J, Schmidt D. Low input cattle finishing. Beef Production Field Day Report Carrington Research Extension Center, NDSU 2002;25:16-7.
[16.] Engel CL, Ilse BR, Anderson VL. Finishing beef cattle on totally mixed and self-fed rations. North Dakota Beef Report; 2013. p. 41.
[17.] Pendlum LC, Boling JA, Bradley NW Energy level effects on growth and conception rates of heifers. J Anim Sci 1977;44:18-22.
[18.] Mouffok C-E, Madani T, Semara L, Ayache N, Rahal A. Correlation between body condition score, blood biochemical metabolites, milk yield and quality in Algerian Montbeliarde cattle. Pakistan Vet J 2013; 33:191 -4.
[19.] Knight TW, Death AF. Effects of oral and injected vitamin A (retinol) supplements on liver vitamin A and plasma carotenoid and cholesterol concentrations in cattle. J Anim Sci 1999;69:607-12.
[20.] Gorocica-Buenfil M, Fluharty F, Bohn T, Schwartz S, Loerch S. Effect of low vitamin A diets with high-moisture or dry corn on marbling and adipose tissue fatty acid composition of beef steers. J Anim Sci 2007;85:3355-66.
[21.] Siebert BD, Kruk ZA, Davis J, et al. Effect of low vitamin a status on fat deposition and fatty acid desaturation in beef cattle. Lipids 2006; 41:365 -70.
[22.] Geary TW, McFadin EL, MacNeil MD, et al. Leptin as a predictor of carcass composition in beef cattle. J Anim Sci 2003;81:1-8.
[23.] Houseknecht KL, Baile CA, Matteri RL, Spurlock ME. The biology Of leptin: a review. J Anim Sci 1998;76:1405-20.
[24.] Yonekura S, Oka A, Noda M, et al. Relationship between serum leptin concentrations and the marbling scores in Japanese Black Cattle. Anim Sci J 2002;73:51-7.
[25.] Burgwald-Balstad LA, Caton JS, Burke VI, Olson KC. Influence of forage level and naloxone injection on feed intake, digestion, and plasma hormone and metabolite concentrations in dairy heifers. J Anim Sci 1995;73:2677-86.
[26.] Montoro C, Ipharraguerre I, Bach A. Blocking opioid receptors alters short-term feed intake and oro-sensorial preferences in weaned calves. J Dairy Sci 2012;95:2531-9.
[27.] Honeyman MS, Russell JR, Morrical DG, et al. Finishing beef cattle on grass supplemented with self-fed by-products. Ames, IA: Iowa State Univ. Anim Indust Report; 2006. 652:13.
[28.] French P, O'Riordan E, Monahan F, et al. Meat quality of steers finished on autumn grass, grass silage or concentrate-based diets. Meat Sci 2000;56:173 -80.
[29.] Loughery HA. The effect of forage level and vitamin A supplements on bovine carcass fat colour [PhD thesis]. Dublin, Ireland: Univ. College Dublin; 2001.
Chan Sung Chung (1,a), Woong Ki Cho (2,a), In Seok Jang (3), Sung Sill Lee (2), Yea Hwang Moon (3,*)
* Corresponding Author: Yea Hwang Moon Tel: +82-55-751-3265, Fax: +82-55-751-3267, E-mail: email@example.com
(1) Gyeonggido Livestock and Veterinary Service, Suwon 16381, Korea
(2) Division of Applied Life Science(Institute of Agriculture & Life Science), BK21 plus, Gyeongsang National University, Jinju 52828, Korea
(3) Department of Animal Science and Biotechnology, Gyeongnam National University of Science and Technology Jinju 52725, Korea
(a) These authors contributed equally to this work. Submitted Mar 3, 2017; Revised Apr 18, 2017; Accepted May 27, 2017
Table 1. Ingredient composition of experimental diets (%) Item CON (1) TMR (1) GP (2) EP (2) LP (2) GP EP LP Corn flake 22.5 30 30 12.5 22 20.5 Wheat bran 30 36.5 33.5 3.85 3.85 3.85 Corn gluten feed 4 4.4 4.8 5 5 5 Molasses 6.5 6.5 6.5 4.5 4.5 4.5 Palm mix 7 12 10 7.2 7.8 10 Soybean meal - 4 12 - - - Soybean hull 13.2 2.1 - - - - Brewer's grain - - - 24 22 23 Wheat hull 12 - - - - - Rye grass - - - 6 8.1 Lupin - - - 1.5 1.5 1.5 Alfafa+timothy - - - 20 18 - hay (3) Rice straw+Mugwort (4) - - - 9.25 9.25 9.25 Base feed (5) - - - - - 8.5 Salt+limestone 2.5 2.5 1.7 1.2 1.1 1.15 Premix (6) 2.3 2 1.5 5 5 4.65 TMR, total mixed ration; GP, growing period; EP, fattening period; LP, finishing period. (1) CON, steers fed concentrate and rice straw separately; TMR, steers fed a TMR. (2) GP, 8-12 month of age; EP, 13-23 month of age; LP, 24-30 month of age. (3) Alfalfa, 50%; Timothy, 50%. (4) Rice straw, 80%; Mugwort, 20%. (5) Corn flake, 38%; corn gluten feed, 6%; wheat bran 41%; soybean meal, 15%. (6) Contained per kg diet: Vitamin A, 180,000 IU;3, 53,000 IU; Vitamin E, 1,500 IU; Mn, 4,400 mg; Zn, 4,400 mg; Fe, 13,200 mg; Cu, 2,200 mg; I, 440 mg; Co, 440 mg. Table 2. Chemical composition of experimental diets Item CON1) GP (2) EP (2) LP (2) Rice straw GP Dry matter (%) 89.23 90.14 89.53 88.00 68.07 Crude protein (% DM) 15.68 13.31 13.40 5.11 14.55 Ether extract (% DM) 2.80 2.77 2.79 2.39 2.98 Crude fiber (% DM) 9.98 8.85 7.23 32.16 16.70 Crude ash (% DM) 7.88 7.22 6.50 17.16 7.24 N-free extract (% DM) 52.89 57.99 59.61 43.18 26.60 NDF (% DM) 49.15 51.25 40.95 75.41 67.71 ADF (% DM) 14.27 13.61 12.26 51.02 25.55 TDN (% DM) 68.50 70.00 73.00 43.23 70.30 Item TMR1) EP LP Dry matter (%) 65.58 65.41 Crude protein (% DM) 13.60 13.36 Ether extract (% DM) 2.22 1.35 Crude fiber (% DM) 15.20 15.20 Crude ash (% DM) 7.10 6.20 N-free extract (% DM) 27.46 29.30 NDF (% DM) 66.55 59.88 ADF (% DM) 25.35 25.45 TDN (% DM) 72.10 77.20 TMR, total mixed ration; GP, growing period; EP, fattening period; LP, finishing period; DM, dry matter; NDF, neutral detergent fiber and; ADF, acid detergent fiber; TDN, total digestible nutrient. (1) CON, steers fed concentrate and rice straw separately; TMR, steers fed a TMR. (2) GP, 8-12 month of age; EP, 13-23 month of age; LP, 24 -30 month of age. Table 3. Effect of feeding system on DM and TDN intakes, body weight gain, and feed conversion of Hanwoo steers Treatments1),2) CON TMR DM intake (kg/d) Growing period (3) 6.55 [+ or -] 0.37 6.65[+ or -]0.21 Fattening period (3) 8.81 [+ or -]0.15 8.96[+ or -]0.06 Finishing period (3) 9.00 [+ or -]0.11 8.29[+ or -]0.19 Average 8.46 [+ or -]0.14 8.33[+ or -]0.10 TDN intake (kg/d) Growing period 4.25 [+ or -]0.13 4.68[+ or -]0.15 Fattening period 6.03[+ or -]0.07 6.42[+ or -]0.04 Finishing period 6.57 [+ or -] 0.08 6.38[+ or -]0.14 Average 5.88[+ or -]0.09 6.09[+ or -]0.08 Body wt. (kg) Initial body wt. 220.9[+ or -]4.58 226.5[+ or -]3.18 Growing period 266.9[+ or -]3.68 273.4[+ or -]2.81 Fattening period 468.7 [+ or -]6.06 465.7[+ or -]3.81 Finishing period 672.7 [+ or -]5.97 640.3[+ or -]3.70 Final body wt. 730.2 [+ or -]14.11 695.7 [+ or -] 10.34 Total body gain 509.3 [+ or -]18.99 469.2[+ or -]22.25 Daily body gain (kg) Growing period 0.79[+ or -]0.04 0.86[+ or -]0.03 Fattening period 0.90[+ or -]0.03 0.77[+ or -]0.02 Finishing period 0.63[+ or -]0.02 0.57[+ or -]0.02 Average 0.79[+ or -]0.02 0.73[+ or -]0.01 Feed conversion Growing period 9.01 [+ or -]0.78 8.30[+ or -]0.72 Fattening period 10.30 [+ or -] 0.52 11.64[+ or -]0.76 Finishing period 14.16 [+ or -] 0.90 14.68[+ or -] 0.92 Average 11.01 [+ or -]0.54 11.23 [+ or -]0.74 p value DM intake (kg/d) Growing period (3) 0.793 Fattening period (3) 0.334 Finishing period (3) 0.002 Average 0.444 TDN intake (kg/d) Growing period 0.038 Fattening period 0.000 Finishing period 0.219 Average 0.105 Body wt. (kg) Initial body wt. 0.312 Growing period 0.173 Fattening period 0.677 Finishing period 0.000 Final body wt. 0.056 Total body gain 0.279 Daily body gain (kg) Growing period 0.160 Fattening period 0.002 Finishing period 0.038 Average 0.010 Feed conversion Growing period 0.592 Fattening period 0.215 Finishing period 0.484 Average 0.226 DM, dry matter; TDN, total digestible nutrient; TMR, total mixed ration; SE, standard error. (1) Mean[+ or -]SE. (2) CON, steers fed concentrate and rice straw separately; TMR, steers fed a TMR. (3) Growing period, 8-12 month of age; fattening period, 13-23 month of age; finishing period, 24-30 month of age. Table 4. Effects of feeding system on plasma biochemical components in Hanwoo steers Treatments1),2) Item CON Aspartate transaminase (U/L) Growing period (3) 57.25[+ or -] 2.98 Fattening period (3) 72.75[+ or -]5.39 Finishing period (3) 82.50[+ or -]2.25 Alanine transaminase (U/L) Growing period 21.75[+ or -]1.11 Fattening period 24.25 [+ or -] 0.98 Finishing period 23.33[+ or -]0.94 Blood urea-N (mg/100 mL) Growing period 11.43 [+ or -] 1.93 Fattening period 13.75[+ or -]1.10 Finishing period 13.33[+ or -] 0.43 Glucose (mg/100 mL) Growing period 91.00 [+ or -]3.19 Fattening period 88.63[+ or -]3.01 Finishing period 90.42[+ or -]3.21 Total protein (g/100 mL) Growing period 6.95[+ or -] 0.10 Fattening period 6.84[+ or -]0.30 Finishing period 7.68[+ or -]0.08 Albumin (g/100 mL) Growing period 3.43[+ or -]0.03 Fattening period 3.49[+ or -]0.14 Finishing period 3.53[+ or -]0.07 Cholesterol (mg/mL) Growing period 183.50[+ or -] 26.57 Fattening period 246.88[+ or -]28.25 Finishing period 208.75 [+ or -] 16.47 Triglyceride (mg/100 mL) Growing period 15.75[+ or -]3.57 Fattening period 14.63 [+ or -] 0.68 Finishing period 13.75[+ or -]1.36 p value Item TMR Aspartate transaminase (U/L) Growing period (3) 80.11[+ or -] 5.09 0.016 Fattening period (3) 91.00 [+ or -]4.29 0.200 Finishing period (3) 89.23[+ or -]2.83 0.119 Alanine transaminase (U/L) Growing period 26.22 [+ or -] 1.48 0.087 Fattening period 28.56[+ or -]1.23 0.390 Finishing period 25.23[+ or -]0.87 0.177 Blood urea-N (mg/100 mL) Growing period 17.27 [+ or -] 0.91 0.009 Fattening period 13.54[+ or -] 0.68 0.868 Finishing period 12.58[+ or -]0.59 0.396 Glucose (mg/100 mL) Growing period 96.78[+ or -]4.58 0.447 Fattening period 93.59[+ or -]4.57 0.488 Finishing period 92.86[+ or -]3.08 0.615 Total protein (g/100 mL) Growing period 6.91 [+ or -]0.29 0.933 Fattening period 6.87[+ or -]0.21 0.928 Finishing period 7.46[+ or -]0.07 0.079 Albumin (g/100 mL) Growing period 3.40[+ or -]0.15 0.917 Fattening period 3.36[+ or -]0.10 0.490 Finishing period 3.42 [+ or -] 0.03 0.138 Cholesterol (mg/mL) Growing period 161.89 [+ or -]8.51 0.486 Fattening period 166.00[+ or -] 7.17 0.024 Finishing period 1 55.23[+ or -]4.53 0.008 Triglyceride (mg/100 mL) Growing period 10.44 [+ or -] 1.40 0.115 Fattening period 10.76 [+ or -] 0.79 0.005 Finishing period 10.59[+ or -] 0.92 0.007 TMR, total mixed ration; SE, standard error. (1) Mean[+ or -]SE. (2) CON, steers fed concentrate and rice straw separately; TMR, steers fed a TMR. (3) Growing period, 8-12 month of age; fattening period, 13-23 month of age; finishing period, 24-30 month of age. Table 5. Concentration of retinol, insulin and leptin of plasma in Hanwoo steers Item Treatments1),2) CON TMR Retinol (lU/mL) Growing period (3) 252.98 [+ or -]37.56 385.88[+ or -]34.53 Fattening period (3) 280.13 [+ or -]49.01 365.05[+ or -]36.62 Finishing pWeriod (3) 294.58[+ or -]35.6, 367.57 [+ or -]34.61 Insulin (ng/mL) Growing period 0.72[+ or -]0.25 0.69[+ or -]0.34 Fattening period 2.18[+ or -]0.38 1.94 [+ or -] 0.30 Finishing period 2.56[+ or -]0.44 2.55[+ or -]0.29 Leptin (ng/mL) Growing period 0.87 [+ or -]0.10 1.52 [+ or -]0.38 Fattening period 2.42[+ or -]0.38 3.47 [+ or -] 0.34 Finishing period 4.93[+ or -]0.42 4.52 [+ or -] 0.23 Item p value Retinol (lU/mL) Growing period (3) 0.021 Fattening period (3) 0.192 Finishing pWeriod (3) 0.185 Insulin (ng/mL) Growing period 0.963 Fattening period 0.652 Finishing period 0.992 Leptin (ng/mL) Growing period 0.291 Fattening period 0.770 Finishing period 0.356 TMR, total mixed ration; SE, standard error. (1) Mean [+ or -]SE. (2) CON, steers fed concentrate and rice straw separately; TMR, steers fed a TMR. (3) Growing period, 8-12 month of age; fattening period, 3 -23 month of age; finishing period, 24-30 month of age. Table 6. Effect of feeding system on carcass yield and quality traits of Hanwoo steers Item Treatments1),2) CON TMR Yield traits3' Carcass wt. (kg) 431.75 [+ or -] 10.70 408.73[+ or -]7.14 Back fat thickness (mm) 11.95 [+ or -] 0.87 13.95 [+ or -]0.72 Rib-eye area ([cm.sup.2]) 96.85[+ or -]2.33 89.88[+ or -]1.59 Meat yield index 66.17[+ or -]0.75 64.54[+ or -]0.52 Meat yield grade 2.15[+ or -]0.67 1.98 [+ or -] 0.62 Quality traits4) Marbling score 5.65[+ or -] 0.48 5.25 [+ or -] 0.32 Fat color 4.75[+ or -]0.10 4.83 [+ or -]0.09 Meat color 3.00[+ or -]0.00 3.13 [+ or -]0.05 Texture 1.15[+ or -] 0.08 1.28 [+ or -]0.07 Maturity 2.15[+ or -] 0.08 2.18 [+ or -]0.06 Meat quality grade 3.65[+ or -]0.23 3.30 [+ or -]0.16 Item p value Yield traits3' Carcass wt. (kg) 0.730 Back fat thickness (mm) 0.980 Rib-eye area ([cm.sup.2]) 0.015 Meat yield index 0.800 Meat yield grade 0.320 Quality traits4) Marbling score 0.098 Fat color 0.599 Meat color 0.023 Texture 0.288 Maturity 0.810 Meat quality grade 0.122 TMR, total mixed ration; SE, standard error. (1) Mean[+ or -]SE. (2) CON, steers fed concentrate and rice straw separately; TMR, steers fed a TMR. (3) Rib-eye area, longissimus dorsi muscle area; meat yield index = 68.184- (0.625xBack fat thickness)+(0.130x Rib-eye area)-(0.024xcarcass weight)+3.23; meat yield grade, highest (3 point) to lowest (1 point). (4) Marbling score, highest (9 point) to lowest (1 point); meat color, very light red (1 point) to very dark red (9 point); fat color, white (1 point) to yellow (9 point); texture, soft (1 point) to rough (3 point); maturity, mature (9 point) to youthful (1 point); quality grade, highest (5 point) to lowest (1 point). Table 7. The correlation coefficients between plasma biochemical compositions and carcass traits of Hanwoo steers Item Yield traits Carcass wt. Back fat Rib-eye Yield thickness area index Retinol -0.406 0.123 - -0.233* -0.060 Insulin -0.018 0.063 - 0.009 -0.047 Leptin -0.030 0.286* - -0.121 -0.274* Glucose 0.137 -0.252* 0.112 0.203 Total protein 0.180 0.167 0.032 -0.183 Albumin 0.172 0.006 0.073 -0.033 Cholesterol 0.312* 0.135 0.255* -0.098 Triglyceride 0.324* -0.161 0.409* 0.207 Item Quality traits Marbling Fat Texture Maturity score color Retinol -0.628* -0.167 0.128 -0.343 Insulin 0.081 -0.229 -0.215 0.030 Leptin -0.028 -0.245 -0.079 -0.082 Glucose 0.124 -0.229 0.182 -0.025 Total protein -0.121 -0.245 0.051 0.054 Albumin -0.180 -0.167 0.230 0.004 Cholesterol -0.243 0.204 0.081 0.201 Triglyceride -0.073 -0.199 -0.015 0.116 * p < 0.05.
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|Author:||Chung, Chan Sung; Cho, Woong Ki; Jang, In Seok; Lee, Sung Sill; Moon, Yea Hwang|
|Publication:||Asian - Australasian Journal of Animal Sciences|
|Date:||Aug 1, 2017|
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