Research Article

 

Assessing the Effect of Fermented Chestnuts on Growth Performance, Carcass Traits, and Meat Quality in Hanwoo Steers During the Late Fattening Period

 

Young-Ho Joo1, Dong-Hyeon Kim1, Hyuk-Jun Lee1, In-Hag Choi2, Hyen-Seok Lee3, Dimas Hand Vidya Paradhipta1,4, Sam-Churl Kim1*

1Gyeongsang National University, Division of Applied Life Science (BK21Plus, Institute of Agriculture & Life Science), Jinju, South Korea; 2Joongbu University, Department of Companion Animal & Animal Resources Sciences, Geumsan, South Korea; 3Ulsan Agricultural Technology Center, Ulsan, South Korea; 4Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta, Indonesia.

 

Received | March 31, 2018; Accepted | May 01, 2019; Published | August 26, 2019

*Correspondence | Sam-Churl Kim, Gyeongsang National University, Division of Applied Life Science (BK21Plus, Institute of Agriculture & Life Science), Jinju, South Korea; Email: kimsc@ gnu.ac.kr

Citation | Joo YH, Kim DH, Lee HJ, Choi IH, Lee HS, Paradhipta DHV, Kim SC (2019). Assessing the effect of fermented chestnuts on growth performance, carcass traits, and meat quality in hanwoo steers during the late fattening period. Adv. Anim. Vet. Sci. 7(9): 770-775.

DOI | http://dx.doi.org/10.17582/journal.aavs/2019/7.9.770.775

ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331

Copyright © 2019 Kim et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

INTRODUCTION

 

During the past 70 years, antibiotic growth promoters have been applied in farm animals to improve growth production and meat quality. Over time, farm animals are frequently exposed to not only the overuse of antibiotics but also antibiotic-resistant bacteria, which are important contributors to the increase in antibiotic resistance. Since 2006, countries in the European Union have banned the use of antibiotics growth promoters in the farm as animal diet (Kroismayr, 2007; Kim et al., 2013). Consequently, various strategies to manipulate cattle diets in the pursuit of improved productivity have been extensively studied. These strategies offer natural alternatives to in-feed antibiotics, such as plant compounds, organic acids, and herbs (Yang et al., 2015; Hunag et al., 2018). Chestnut was classified as a fruit rich in tannins, containing water-soluble polyphenolic compounds that exist abundantly in nature (Goel et al., 2005). Dietary chestnut at 5% for pig increase feed intake and digestibility (Lee et al., 2016). In poultry, supplementation of chestnut tannin at 250/500 mg/kg in the feed increase body weight and feed conversion (Jamroz et al., 2009). On the ruminants, there are numerous studies on the use of chestnuts tannins in nutrition and production that had benefit on N utilization and decreasing CH4 emission (Deaville et al., 2010; Liu et al., 2011).

 

In the past, tannins were considered as anti-nutritional substances that decreased the digestibility of grazing animals, but it is now known that the biological activities of dietary tannins positively affect average daily gain and reduce bloating in steers grazing winter wheat (Min et al., 2006). In terms of meat quality, evidence has shown that tannins are mainly related to color stability and shelf life (Luciano et al., 2009; Luciano et al., 2011). That evidence can support that dietary chestnut tannins have similar effects with antibiotics and its advance research can help to decrease the use of antibiotics for livestock production. However, few studies have investigated the effects of fermented chestnuts on the meat quality of animals. Chestnuts are produced annually in South Korea, but part of the annual chestnut production becomes waste. Thus, other strategies to utilize chestnuts include their application as a dietary supplement for Hanwoo steers through the fermentation process. In our hypothesis, application of chestnut tannins in beef cattle could improve performance and its meat quality considering beneficial effect of tannins. Therefore, the aim of this study was to examine the effect of growth performance and meat quality on Hanwoo steers fed fermented chestnuts during the late fattening period.

 

MATERIAL AND METHODS

 

All animal procedures were conducted at Woojung farm (Changwon, South Korea) and approved by the administration office of Gyeongsang National University (Jinju, South Korea) under the animal care and use guidelines of the Animal Research Unit.

 

Fermented Chestnut

Chestnut samples were obtained from the Hapcheon Agricultural Co-operative Society (Hapcheon, South Korea). The chestnut was dried in a forced-air oven at 60°C for 48 h and ground in a hammer mill to obtain particles with a diameter of 5–10 mm. For the fermentation process, 5 kg of chestnut powder was mixed with 2.4 L of distilled water, 15 g of molasses, and 100 mL of Bacillus subtilis (2 × 109 CFU/mL). After sealing, the mixture was incubated at 39°C for 48 h in a shaking incubator for seven days. During incubation, the mixture was gently shaken for 30 min at three-hour intervals.

 

Animals and Diets

A total of 18 castrated Hanwoo steers (average initial body weight of 615.8 ± 1.0 kg, 28 months old) were assigned to two groups (control vs. treatment). Each group consisted of nine Hanwoo steers that were placed in three pens as replications (three steers per pen) for 72 days of feeding period. The Hanwoo steers in the control group were fed a concentrate mix and rice straws, whereas those in the treatment group received the control diet plus 5% as fed of fermented chestnuts. The Hanwoo steers were placed in a pen (5 m × 8 m) installed with a feeder in a slatted floor. Water was offered ad libitum during the experimental period. The diet was fed at 2.5% dry matter (DM) of the body weight of the steers in two equal portions at 09:00 h and 17:00 h daily. The Hanwoo steer received concentrate/roughage at a ratio of 60:40 on the DM basis. The experimental diets were formulated isonitrogenous and isocaloric to supply nutrient requirement of late fattening period according to the Korean Feeding Standards for Korean Cattle developed by the National Livestock Research Institute (KFS, 2007). The composition of the ingredients in the experimental diets is summarized in Table 1. Analysis of experimental diets (Table 1) was performed according to the methods of the Association of Official Agricultural Chemists (AOAC, 2005). Feed intake was calculated daily by measuring orts before morning feeding. For growth performance, the Hanwoo steers were weighed at the beginning (initial body weight) and the end of feeding period (final body weight) to determine average daily gain and average daily feed intake for the entire feeding period. Feed efficiency was calculated as the ratio between average body weight gain and feed intake on the basis of DM.

 

Table 1: Chemical compositions of experimental diets (%, DM)

Item	Concentrates	Rice straw	Chestnut
Dry matter	90.64±0.211	87.94±0.34	89.12±0.30
Crude protein	12.91±0.12	5.02±0.10	9.41±0.23
Ether extract	4.36±0.08	2.01±0.03	1.67±0.19
Crude ash	23.84±0.17	60.03±0.06	1.99±0.13
Neutral detergent fiber	11.24±0.13	49.27±0.34	37.19±0.31
Acid detergent fiber	5.84±0.29	6.48±0.35	20.46±0.47

 

1Mean±standard deviation.

Values represent triplicate assays on triplicate samples.

 

Carcass Traits

At the end of the feeding period, all Hanwoo steers fasted for 24 h and were moved to a local municipal slaughterhouse (Gosung, South Korea) to evaluate carcass yield and quality. Following a 24-h carcass chill, cold carcass weights were measured, and the left side of the carcass was opened between the 13th rib and the 1st lumbar vertebrae to measure back fat thickness and the longissimus muscle area. The yield and quality grade in each carcass were determined according to the Korean carcass grading procedure classified by the Korean Livestock Enforcement Regulation (KMAF, 2007). The degree of marbling and scores of meat color and fat color were evaluated according to the Korean Beef Marbling Standard and the Color Standard (KAPE, 2012), respectively. Marbling score ranged from 1 (poor) to 9 (excellent) with higher numbers indicating better quality. The score of meat color ranged from 1 (scarlet) to 7 (dark red) and fat color was graded from 1 (white) to 7 (dark yellow).

 

Analysis

The moisture, crude protein, and crude fat contents of meat samples were determined following the methods of the AOAC (2005). After 24 h postmortem, approximately 10 g of minced meat was added to 90 mL of distilled water and homogenized for 1 min. The pH of the homogenized sample was determined using a pH meter. For cooking loss, approximately 100 g of meat sample in a polyethylene bag was boiled in a water bath at 70℃ for 30 min and cooled at room temperature for 30 min. Cooking loss was calculated as the difference in meat weight before and after cooking. Water-holding capacity was measured according to the method described by Kristensen and Purslow (2001). First, 0.5 g of muscle sample in each line was placed in a centrifugation tube with filter units. The samples were heated for 20 min at 80℃ and then cooled for 10 min. After centrifuging at 2,000 × g for 10 min at 4℃, the water-holding capacity was calculated as the change in sample weight. Shear force values were measured using a rheometer (CR-300, Sun Scientific Co., Tokyo, Japan). Each core was sheared in parallel to the muscle fibers using Warner-Bratzler attachment to the load cell with 5 kg applied at a cross-head speed of 30 mm/min. Fatty acids were extracted from the LD muscle using a mixture of chloroform/methanol (2:1, vol/vol) following the method described by Folch et al. (1957). Fatty acid methyl esters were analyzed by gas chromatography (GA-17A, Shimadzu, Tokyo, Japan) equipped with a flame ionization detector and a CP-Sil 88 column (100 m × 0.25 mm × 0.2 µm; Chrompack, Middelburg, Netherlands). Fatty acid peaks (C14:0 to 24:1) were identified by comparison of the retention times in the standard fatty acid methyl ester mixtures (Sigma-Aldrich, Germany). Fatty acid data were presented as a percentage of each individual fatty acid relative to total fatty acids.

 

Statistical Analysis

All data are expressed as the mean ± standard error of the mean. All statistical procedures were carried out using the generalized linear model procedure of the SAS statistical package (SAS Institute, 2004). The model was Yij = µ + Ti + eij, where Yij = response variable, µ = overall mean, Ti = the effect of treatment i, eij = error term. The significant differences between the means were declared at p < 0.05 using Student’s t-test, while the tendency differences were declared at p < 0.1.

 

RESULTS AND DISCUSSION

 

The growth performance of Hanwoo steers fed fermented chestnuts during the late fattening period are shown in Table 2. The chestnut tannin reduces the N loss production and CH4 emission in the ruminants that indicate an improvement on digestive utilization of feed (Deaville et al., 2010; Liu et al., 2011). Moreover, it increases flow rate of amino acid in small intestine that can be absorbed highly by ruminant. By these effects, the chestnut tannin may influence the growth performance of ruminant (Frutos et al., 2004). However, initial body weight, final body weight, average daily gain, average daily feed intake, and feed efficiency were not different between the two groups (p > 0.05) in the present study. Similar results were reported by Krueger et al. (2010), where tannin treatment did not improve growth performance during the 42-day fattening period. In the current study, supplementation of fermented chestnut at 5% had lower beneficial effects on growth performance and meat quality than control. This might be due to the characteristics of the fermented chestnuts, which depend on the origin of tannins and the fermentation process (Frutos et al., 2004). For example, high tannin intake has no positive effect on productivity, voluntary feed intake, and digestibility, whereas nutrient availability is decreased because of the strongly formed complexes between tannins and other macromolecules (Frutos et al., 2004). Ultimately, the 5% fermented chestnuts applied in our study did not show detrimental effects on growth performance.

 

Table 2: Effects of fermented chestnut supplementation on growth performance of Hanwoo steer

 

Item	Control	5% FCN1	SEM2	p-value
Initial bodyweight (kg)	615.2	616.4	5.006	0.971
Final body weight (kg)	679.0	669.1	6.220	0.807
Average daily gain (kg/d)	0.886	0.732	0.343	0.497
Average daily feed intake (kg/d, DM)	12.0	10.2	1.358	0.538
Feed efficiency (Gain:Intake)	5.32	5.16	1.785	0.325

 

15% FCN: 5% fermented chestnut.

2SEM: Standard error of the mean.

 

Table 3 presents the carcass traits of Hanwoo steers supplemented with fermented chestnuts. The addition of 5% fermented chestnuts to the diet exhibited no remarkable effect on cold carcass weight, backfat thickness, longissimus muscle area, marbling score, and fat color (p > 0.05). The results of this study agree with those of Krueger et al. (2010), as different types of tannins (chestnut tannin and mimosa tannin) exerted no effect on selected carcass traits in steers. However, back fat thickness and longissimus muscle area were lower in Hanwoo steers fed 5% fermented chestnuts. Although the most important factors in evaluating beef quality are marbling score, meat color, and fat color, the mechanisms of fermented chestnuts with respect to carcass traits are uncertain. Moreover, the type and concentration of tannin could be different among sources, which might not always be a promising improvement in animal performance and carcass quality (Krueger et al., 2010).

 

Table 3: Effects of fermented chestnut supplementation on carcass traits loin in Hanwoo steer

 

Item	Control	5% FCN1	SEM2	p-value
Cold carcass weight (kg)	397.2	391.4	38.38	0.807
Backfat thickness (mm)	11.2	10.0	3.820	0.633
Longissimus muscle area (cm2)	83.2	79.2	6.321	0.346
Marbling score3	4.4	4.4	2.000	0.760
Meat color4	5.0	4.8	0.592	0.608
Fat color5	3.0	2.8	0.316	0.347

 

15% FCN: 5% fermented chestnut.

2SEM: Standard error of the mean.

3Scored: grade 1 (poor) through grade 9 (excellent).

4Scored: grade 1 (scarlet) through grade 7 (dark red).

5Scored: grade 1 (white) through grade 7 (dark yellow).

 

Table 4 summarizes the data concerning the chemical composition, physicochemical characteristics, and fatty acid profiles in Hanwoo steers fed fermented chestnuts. With regards to chemical composition, moisture and crude protein content in the loins of Hanwoo steers fed 5% fermented chestnuts were equal to those of control Hanwoo steers loins. There was a numerical lower crude fat content was observed in Hanwoo steers fed 5% fermented chestnuts compared with control. At present, the reasons for the reduction in crude fat by 5% fermented chestnuts are unclear. In addition, the biological activities of plant tannins and animal responses to tannins have been extensively reviewed, mainly focusing on ruminant nutrition and production with respect to proteins (Hunag et al., 2018). In terms of physicochemical characteristics, changes in meat quality parameters, which contribute to cooking loss, water-holding capacity, and shelf life, can markedly influence meat pH (Li et al., 2014). In the current study, the addition of 5% fermented chestnuts to the diet of Hanwoo steers during the late fattening did not affect these factors. To the best of our knowledge, information on meat quality using fermented chestnuts as a source of tannins for ruminants is

 

Table 4: Effects of fermented chestnut supplementation on chemical compositions, physico-chemical characteristics, and fatty acid profiles of loin in Hanwoo steer

 

Item	Control	5% FCN1	SEM2	p-value
Chemical compositions (%)
Moisture	66.97	65.44	0.63	0.163
Crude protein	17.33	17.45	0.60	0.174
Crude fat	9.74	6.00	0.73	0.106
Physicochemical characteristics
pH	5.46b	5.68a	0.02	0.001
Cooking loss (%)	33.78	32.98	0.63	0.628
Water-holding capacity (%)	78.27	79.26	1.92	0.762
Shear force (kg/cm2)	3.48	3.51	0.15	0.821
Fatty acid profiles (%)
Myristic acid (C14:0)	3.81	3.20	0.789	0.256
Palmitic acid (C16:0)	29.2	28.0	1.982	0.708
Palmitoleic acid (C16:1)	5.03	4.61	0.728	0.256
Margaric acid (C17:0)	0.57	0.54	0.257	0.084
Margaroleic Acid (C17:1)	0.63a	0.49b	0.067	0.014
Stearic acid (C18:0)	9.91b	11.9a	0.644	0.041
Oleic acid (C18:1c-9)	47.3	46.2	1.469	0.257
Linoleic acid (C18:2n-6)	3.04	3.97	1.473	0.101
Arachidonic acid (C20:4n-6)	0.51b	1.09a	0.396	0.049
Saturated fatty acid (SFA)	43.5	43.6	2.135	0.612
Unsaturated fatty acid (UFA)	56.5	56.4	2.135	0.612
SFA/UFA	0.76	0.77	0.067	0.613

 

a,bMeans in the same row with different superscripts differ significantly (p < 0.05).

15% FCN: 5% fermented chestnut.

2SEM: Standard error of the mean.

 

rather limited. Considering individual fatty acids, our result showed no significant difference in the percentages of myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), margaric acid (C17:0), oleic acid (C18:1c-9), and linoleic acid (C18:2n-6) between the two groups (p > 0.05). However, fermented chestnut supplementation exerted an effect on the percentages of margaroleic acid (C17:1), stearic acid (C18:0), and arachidonic acid (C20:4n-6) (p < 0.05). As the major fatty acid profile, stearic acid largely is produced throughout biohydrogenated oleic acid by ruminal microbes. Moreover, dietary fiber increases stearic acid concentration in duodenal flow (Smith et al., 2009). Addition of fermented chestnut in the present study could increase the total fiber content in the diet, which might increase stearic acid concentration in the loin. Overall, the percentages of individual fatty acids were similar between the two groups. In the present study, the addition of fermented chestnuts into Hanwoo steers diets did not increase or decrease the relative percentages of saturated fatty acids (SFA) and unsaturated fatty acids (UFA), and the SFA:UFA ratio compared with those in the control groups (p > 0.05). This implied that the use of fermented chestnuts led to poor efficiency in improving fatty acids via antioxidant effects. Recently, the potential application of tannins as biological antioxidants has been reported in several studies in cattle and sheep (Dey and De, 2014; Peng et al., 2016). However, the antioxidant mechanism of fermented chestnuts in Hanwoo steers is unknown.

 

CONCLUSION

 

The study revealed that the addition of 5% fermented chestnuts to Hanwoo steers diets had no obvious effects on growth performance, carcass traits, and meat quality. In turn, no negative effect of fermented chestnuts was demonstrated. The effects of optimal levels of fermented chestnuts on production and meat quality and their mechanisms in Hanwoo steers fatteners warrant further investigation.

 

ACKNOWLEDGEMENTS

 

This research was supported (Project No. 315017-05-2-SB030) by IPET (Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry and Fisheries), and Ministry of Agriculture, Food and Rural Affairs, Republic of Korea.

 

CONFLICT OF INTEREST

 

The author declares there is no conflict of interests.

 

AUTHORS CONTRIBUTION

 

Young-Ho Joo, Dong-Hyeon Kim, Sam-Churl Kim: Conception and design of study.

Young-Ho Joo, Hyuk-Jun Lee, Hyen-Seok Lee: Acquisition and analysis of data.

Young-Ho Joo, In-Hag Choi, Hyen-Seok Lee, Sam-Churl Kim: Drafting the manuscript.

Dong-Hyeon Kim, In-Hag Choi, Dimas Hand Vidya Paradhipta, Sam-Churl Kim: Critical review.

 

REFERENCES

 

• AOAC (2005). Official methods of analysis (18th ed.). Washington, DC: AOAC.

• Deaville ER, Givens DI, Mueller-Harvey I (2010). Chestnut and mimosa tannin silages: Effects in sheep differ for apparent digestibility, nitrogen utilisation and losses. Anim. Feed. Sci. Technol. 157(3-4): 129-138. https://doi.org/10.1016/j.anifeedsci. 2010. 02.007.

• Dey A, De PS (2014). Influence of condensed tannins from Ficus bengalensis leaves on feed utilization, milk production and antioxidant status of crossbred cows. Asian-Australas J. Anim. Sci. 27(3): 342-348. https://doi.org/10.5713/ajas.2013.13295.

• Folch J, Lees M, Sloane-Stanley GH (1957). A simple method for the isolation and purification of total lipides from animal tissues. J. Biolog. Chem. 226(1): 497-509.

• Frutos P, Hervás G, Giráldez FJ, Mantecón AR (2004). Review. Tannins and ruminant nutrition. Span Jagri. Res. 2(2): 191-202. https://doi.org/10.5424/ sjar/2004 022-73.

• Goel G, Puniya AK, Aguilar CN, Singh K (2005). Interaction of gut microflora with tannins in feeds. Naturwissenschaften. 92(11): 497-503. https://doi.org/10.1007/s00114-005-0040-7

• Hunag Q, Liu X, Zhao G, Hu T, Wang Y (2018). Potential and challenges of tannins as an alternative to in-feed antibiotics for farm animal production. Anim. Nutri. 4(2): 137-150. https://doi.org/10.1016/j.aninu.2017.09.004.

• Jamroz D, Wiliczkiewicz A, Skorupinska J, Orda J, Kuryszko J, Tschirch H (2009). Effect of sweet chestnut tannin (SCT) on the performance, microbial status of intestine and histological characteristics of intestine wall in chickens. Br. Poult. Sci. 50: 687–699. https://doi.org/10.1080/00071660903191059.

• Kim YJ, Chung TH, Choi IH (2013). Influence of supplemental Schisandra chinensis powder on growth performance, serum cholesterol, and meat quality of broilers. Acta. Agri. Scand. A. 63(4): 175-182. https://doi.org/10.1080/09064702.2013.861861.

• KFS (2007). Korean Feeding Standard for Korean Cattle (Hanwoo). National Livestock Research Institute, Rural Development Administration, Ministry of Agriculture and Forestry, South Korea.

• KAPE (2012). The beef carcass grading. Retrieved on May 15, 2012 from www. kormeat.co.kr/01-intro/13-2.asp.

• KMAF (2007). Carcass grading standards. Livestock Regulation Practice (Appendix no. 4). Sejong, KOR: KMAF.

• Kristensen L, Purslow PP (2001). The effect of ageing on the water-holding capacity of pork; role of cytoskeletal proteins. Meat Sci. 58(1): 17-23. https://doi.org/10.1016/S0309-1740 (00)00125-X.

• Kroismayr A (2007). Natural growth promoters-a worldwide opportunity [online]. Accessed 1 May 2007, available at: http://www.pigprogress.net/Growing-Finishing/Management/ 2007 /5/Natural-growth-promoters---a-worldwide-opportunity-PP005740W/.

• Krueger WK, Gutierrez-Banuelos H, Carstens GE, Mind BR, Pinchak WE, Gomez RR, Andersonc RC, Krueger NA, Forbes TDA (2010). Effects of dietary tannin source on performance, feed efficiency, ruminal fermentation, and carcass and non-carcass traits in steers fed a high-grain diet. Anim. Feed. Sci. Technol. 159(1-2): 1-9. https://doi.org/ 10.1016/j.anifeedsci.2010.05.003.

• Lee HJ, Choi IH, Kim DY, Amanullah SM, Kim SC (2016). Nutritional characterization of tannin rich chestnut (Castanea) and its meal for pig. J. Appl. Anim. Res. 44(1): 258-262. https://doi.org/ 10.1080/09712119.2015.1031779.

• Li P, Wang T, Mao Y, Zhang Y, Niu L, Liang R, Zhu L, Luo X (2014). Effect of ultimate pH on postmortem myofibrillar protein degradation and meat quality characteristics of Chinese Yellow crossbreed cattle. Sci. World J. 2014(174253): 1-8. https://doi.org/10.1155 /2014/ 174253.

• Liu HW, Vaddella V, Zhou D (2011). Effects of chestnut tannins and coconut oil on growth performance, methane emission, ruminal fermentation, and microbial populations in sheep. J. Dairy. Sci. 94(12): 6069-6077. https://doi.org/10.3168/jds.2011-4508.

• Luciano G, Monahan FJ, Vasta V, Biondi L, Lanza M, Priolo A (2009). Dietary tannins improve lamb meat colour stability. Meat Sci. 81(1): 120-125. https://doi.org/10.1016/j. meat sci.2008.07.006.

• Luciano G, Vasta V, Monahan FJ, Lopez-Andres P, Biondi L, Lanza M, Priolo A (2011). Antioxidant status, colour stability and myoglobin resistance to oxidation of longissimus dorsi muscle from lambs fed a tannin-containing diet. Food Chem. 124(3): 1036-1042. https://doi.org/10.1016/j.foodchem.2010.07.070.

• Min BR, Pinchak WE, Anderson RC, Fulford JD, Puchala R (2006). Effects of condensed tannins supplementation level on weight gain and in vitro and in vivo bloat precursors in steers grazing winter wheat. J. Anim. Sci. 84(9): 2546-2554. https://doi.org/10.2527/jas. 2005-590.

• Peng K, Shirley DC, Xu Z, Huang QQ, Mcallister TA, Chaves AV (2016). Effect of purple prairie clover (Dalea purpurea, vent.) hay and its condensed tannins on growth performance, wool growth, nutrient digestibility, blood metabolites and ruminal fermentation in lambs fed total mixed rations. Anim. Feed Sci. Technol. 222: 100-110. https://doi.org/10.1016/j.anifeedsci.2016.10.012.

• Smith SB, Gill CA, Lunt DK, Brooks MA (2009). Regulation of fat and fatty acid composition in beef cattle. Asian-Australas. J. Anim. Sci. 22(9): 1225-1233. https://doi.org /10.571/ajas.2009.r.10.

• SAS (2004). SAS/STAT User guide, version 9.1.2. Cary, NC: SAS Institute Inc.

• Yang C, Chowdhury MA, Huo Y, Gong J (2015). Phytogenic compounds asalternatives to in-feed antibiotics: potentials and challenges in application. Pathogens. 4(1): 137-56. https://doi.org /10.3390/pathogens4010137.