AU2021103155A4

AU2021103155A4 - Use of guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle

Info

Publication number: AU2021103155A4
Application number: AU2021103155A
Authority: AU
Inventors: Zengmin Li; Huan LIANG; Mingren Qu; Long Wang; Junping Xin; Lanjiao Xu; Hanjing Yu; Wenjing Zhang
Original assignee: Jiangxi Agricultural University
Current assignee: Jiangxi Agricultural University
Priority date: 2021-03-24
Filing date: 2021-06-07
Publication date: 2021-07-22
Anticipated expiration: 2029-06-07
Also published as: CN113016939A

Abstract

OF THE DISCLOSURE The present disclosure relates to the field of feed additives, and in particular to use of guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle. The present disclosure provides the use of guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle. The guanidineacetic acid is administered at a daily dose of 5-40 g/cattle. The guanidineacetic acid of the present disclosure can ameliorate rumen fermentation, raise the average daily gain of the beef cattle, reduce feed-gain ratio, increase body antioxidant capacity, carcass weight, and loin eye area, lower drip loss of beef, and effectively improve the production performance, slaughter performance, and meat quality of the beef cattle.

Description

USE OF GUANIDINEACETIC ACID IN IMPROVING PRODUCTION PERFORMANCE, SLAUGHTER PERFORMANCE, AND MEAT QUALITY OF BEEF CATTLE TECHNICAL FIELD

[01] The present disclosure relates to the field of feed additives, and in particular to use of guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle.

BACKGROUNDART

[02] With the continuous improvement of people's living standard, people's demand for meat products is increasing rapidly in quantitative terms, and the demand for quality is increasing continuously. People are not satisfied with pork and poultry any more; beef, as high-quality and highly nutritious meat, is being demanded increasingly due to high quality thereof. At present, in China, beef has been the third largest meat after pork and poultry; relative to pigs and poultry, beef cattle has shortcomings of long breeding time, low reproduction rate, and high breeding cost, and further, the demand for beef exceeds the supply. Substantial experts and scholars are continuously investigating and exploring how to shorten the breeding time, reduce the cost and improve beef quality.

[03] Nutritional regulation is one of the most important and effective means for improving production performance of beef cattle. Guanidineacetic acid (GAA), a novel nutritional feed additive, is the only precursor for synthesizing creatine in vertebrates; in the animal body, GAA is methylated to form creatine to exert biological functions thereof, and serves as a key substance for energy transfer of all living cells in the animal body. Relative to creatine, GAA is inexpensive, structurally stable, and very convenient to use; so far, research on how GAA regulates the rumen fermentation, production performance, slaughter performance, and meat quality of the beef cattle has not been reported yet, and it is unclear whether to improve the production performance of the beef cattle.

SUMMARY

[04] Preferred embodiments of the present invention seek to use guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle. The guanidineacetic acid used can improve rumen fermentation, increase the average daily gain of the beef cattle, reduce feed-gain ratio, increase body antioxidant capacity, carcass weight, and loin eye area, drip loss of beef, and effectively improve the production performance, slaughter performance, and meat quality of the beef cattle.

[05] The present disclosure provides the following technical solutions:

[06] use of guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle, where the guanidineacetic acid is administered at a daily dose of 5-40 g/cattle.

[07] Preferably, the guanidineacetic acid may be administered at a daily dose of 20 g/cattle.

[08] The present disclosure provides a feed composition for improving production performance, slaughter performance, and meat quality of beef cattle, including individually packaged mixed concentrate and roughage; where the mixed concentrate includes guanidineacetic acid and concentrate; the concentrate includes the following components: 5 0 - 7 0 % by weight of corn, 5- 2 0

% by weight of wheat bran, 10-40% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix;

[09] based on 1 kg of premix, the premix includes 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 10 mg of Co, 130 g of Ca, and 30 g of P;

[10] the roughage includes one or more of Pennisetum purpureum (elephant grass) silage, Pennisetum sinese silage, corn silage, peanut hay, corn stalk, and rice straw.

[11] The present disclosure provides a method for improving production performance, slaughter performance, and meat quality of beef cattle, including the following steps:

[12] feeding the beef cattle with the foregoing mixed concentrate and roughage successively per meal.

[13] Preferably, the mixed concentrate and the roughage may be fed twice or thrice a day.

[14] Preferably, the feeding amount of the guanidineacetic acid may be 2.5-20 g/cattle each time.

[15] Preferably, the daily consumption of the concentrate may be 0.8-1.8% of the body weight of the beef cattle.

[16] Preferably, the mixed concentrate and the roughage may have a mass ratio of (4-7):(3-6) based on the dry matter.

[17] Beneficial effects are as follows: The present disclosure provides the use of guanidineacetic acid in improving production performance, slaughter performance, and meat quality of beef cattle. The guanidineacetic acid is administered at a daily dose of 5-40 g/cattle. The guanidineacetic acid used can raise the average daily gain of the beef cattle, reduce feed-gain ratio, enhance body antioxidant capacity, ameliorate rumen fermentation, increase carcass weight and loin eye area, lower drip loss of beef, and effectively improve the production performance, slaughter performance, and meat quality of the beef cattle.

[18] Moreover, the guanidineacetic acid of the present disclosure is nontoxic, free of side effects, and environmentally friendly, and serves as a very excellent antibiotic alternative that avoids drug residues and other problems present in the existing antibiotics.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[19] Unless otherwise stated, all materials used in the present disclosure are conventionally purchased by those of skill in the art.

[20] The present disclosure provides use of guanidineacetic acid (GAA) in improving production performance, slaughter performance, and meat quality of beef cattle, where the GAA may be administered at a daily dose of 5-40 g/cattle, preferably 10-40 g/cattle, and more preferably 20 g/cattle.

[21] The GAA of the present disclosure may increase the content of creatine and adenosine triphosphate (ATP) in animal cells and the body energy reserve, is nontoxic, free of side effects, and environmentally friendly, and serves as a very excellent antibiotic alternative that avoids drug residues and other problems present in the existing antibiotics. The GAA may further raise average daily gain (ADG) of the beef cattle, reduce feed-gain ratio, perfect the feed efficiency, elevate the content of superoxide dismutase (SOD) in beef cattle serum, enhance the body antioxidant capacity of the beef cattle, ameliorate rumen fermentation, increase carcass weight and loin eye area, lower drip loss of beef, and effectively improve the production performance, slaughter performance, and meat quality of the beef cattle.

[22] The present disclosure provides a feed composition for improving production performance, slaughter performance, and meat quality of beef cattle, including individually packaged mixed concentrate and roughage; where the mixed concentrate includes guanidineacetic acid and concentrate; the concentrate may include the following components: 50-70% by weight of corn, 5 % by weight of wheat bran, 10-40% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix, and more preferably 60% by weight of corn, 10% by weight of wheat bran, 25% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix; based on 1 kg of premix, the premix includes 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 10 mg of Co, 130 g of Ca, and 30 g of P; the roughage includes one or more of elephant grass silage, P sinese silage, corn silage, peanut hay, corn stalk, and rice straw. In the present disclosure, an appropriate amount of the corn and the wheat bran used in the concentrate may provide sufficient energy for the beef cattle; meanwhile, the wheat bran is more inexpensive than the corn, and appropriate addition thereof may reduce feed costs; the soybean meal is the most important in livestock and poultry diets and serves as a vegetable protein feed with the best quality, providing proteins and essential amino acids for the beef cattle; the calcium bicarbonate belongs to a mineral feed that mainly provides calcium for the beef cattle; the premix mainly supplement vitamins and trace elements, and provides sufficient nutrients for the beef cattle in cooperation with the foregoing components, ensuring the normal growth of the beef cattle.

[23] In the specific examples of the present disclosure, the silage may preferably be prepared by rolling, cutting and fermentation of silage plants. In the present disclosure, the silage plants may include one and more of elephant grass, P sinese, and corn; the fermentation may preferably be conducted in a silo bin; the fermentation may preferably be implemented by anaerobic fermentation, and specific operations may preferably include the steps of filling of rolled and cut silage plants in the silo bin, compaction, sealing, and fermentation; the fermentation may preferably be conducted for 30-50 days, and more preferably 40-45 days; the fermentation may preferably be conducted at a temperature of 10-30°C, and more preferably 18-25°C.

[24] The present disclosure provides a method for improving production performance, slaughter performance, and meat quality of beef cattle, including the following steps:

[25] feeding the beef cattle with the foregoing mixed concentrate and roughage successively per meal.

[26] In the present disclosure, the beef cattle are fed with the foregoing mixed concentrate and roughage successively per meal. In the present disclosure, the concentrate may preferably be fed twice or thrice a day, and more preferably twice a day; the daily consumption of the concentrate may preferably be 0.8-1.8% and more preferably 1.0-1.5% of the body weight of the beef cattle. In the specific examples of the present disclosure, the ratio decreases as the body weight of the beef cattle increases, for example, a beef cattle weighing 350 kg requires 5.25 kg (1.5%) of concentrate per day, and that weighing 700 kg requires 7 kg (1%) of concentrate per day.

[27] In the present disclosure, the GAA may preferably be administered at a dose of 2.5-20 g/cattle, more preferably 5-20 g/cattle, and most preferably 10-15 g/cattle each time; the GAA is purchased from Shandong E.fine Pharmacy Co., Ltd.

[28] In the present disclosure, the concentrate and the roughage may preferably fed as follows: after the beef cattle eats up the concentrate, the roughage is fed to enable the beef cattle to eat up all concentrate, so that the GAA completely enters into the beef cattle, ensuring that the GAA can achieve an effect of improving the production performance of the beef cattle.

[29] In the present disclosure, the roughage may preferably be fed twice or thrice a day, and more preferably twice a day. In the present disclosure, the mixed concentrate and the roughage may preferably have a mass ratio of (4-7):(3-6), and more preferably 4:6, based on the dry matter.

[30] To further illustrate the present disclosure, the use of GAA in improving production performance, slaughter performance, and meat quality of beef cattle provided by the present disclosure will be described in detail below in conjunction with examples, but they should not be construed as limiting the protection scope of the present disclosure.

[31] Example 1

[32] (1) A mixed concentrate was obtained by stirring 2.5 g of GAA well with the concentrate that fed each beef cattle per meal; the daily consumption of the concentrate was 1.5% of the body weight of the beef cattle; herein, the concentrate was composed of the following raw materials: 60% by weight of corn, 10% by weight of wheat bran, 25% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix; the premix was as follows: each kilogram of premix contained: 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 10 mg of Co, 130 g of Ca, and 30 g of P.

[33] (2) The beef cattle was fed with the mixed concentrate obtained in step (1) and then roughage, twice a day; the mixed concentrate and the roughage had a mass ratio of 4:6 based on the dry matter. Herein, the roughage was elephant grass silage, and the elephant grass silage was prepared as follows: the elephant grass was mown on sunny days, with a stubble height of 10 cm; subsequently, the elephant grass was rolled and cut, filled in a silo bin, compacted, sealed, and fermented at 25°C for 42 days; after that, the silo bin was opened, and the silage was used.

[34] Example 2

[35] (1) A mixed concentrate was obtained by stirring 5 g of GAA well with the concentrate that fed each beef cattle per meal; the daily consumption of the concentrate was 1.5% of the body weight of the beef cattle; herein, the concentrate was composed of the following raw materials: 60% by weight of corn, 10% by weight of wheat bran, 25% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix; the premix was as follows: each kilogram of premix contained: 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 1 mg of Co, 130 g of Ca, and 30 g of P.

[36] The beef cattle was fed with the mixed concentrate obtained in step (1) and then roughage, twice a day; the mixed concentrate and the roughage had a mass ratio of 4:6 based on the dry matter. Herein, the roughage was elephant grass silage, and the preparation method of the elephant grass silage was the same as that in Example 1.

[37] Example 3

[38] (1) A mixed concentrate was obtained by stirring 10 g of GAA well with the concentrate that fed each beef cattle per meal; the daily consumption of the concentrate was 1.5% of the body weight of the beef cattle; herein, the concentrate was composed of the following raw materials: 60% by weight of corn, 10% by weight of wheat bran, 25% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix; the premix was as follows: each kilogram of premix contained: 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 10 mg of Co, 130 g of Ca, and 30 g of P.

[39] The beef cattle was fed with the mixed concentrate obtained in step (1) and then roughage, twice a day; the mixed concentrate and the roughage had a mass ratio of 4:6 based on the dry matter. Herein, the roughage was elephant grass silage, and the preparation method of the elephant grass silage was the same as that in Example 1.

[40] Example 4

[41] (1) A mixed concentrate was obtained by stirring 20 g of GAA well with the concentrate that fed each beef cattle per meal; the daily consumption of the concentrate was 1.5% of the body weight of the beef cattle; herein, the concentrate was composed of the following raw materials: 60% by weight of corn, 10% by weight of wheat bran, 25% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix; the premix was as follows: each kilogram of premix contained: 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 10 mg of Co, 130 g of Ca, and 30 g of P.

[42] The beef cattle was fed with the mixed concentrate obtained in step (1) and then roughage, twice a day; the mixed concentrate and the roughage had a mass ratio of 4:6 based on the dry matter. Herein, the roughage was elephant grass silage, and the preparation method of the elephant grass silage was the same as that in Example 1.

[43] Application Example 1

[44] Effects of diet supplemented with GAA on the production performance and nutrient digestibility of the beef cattle

[45] (1) Experimental design

[46] Single factor test design was used; according to the level of GAA added, 45 Jinjiang cattle were randomized into five groups: Group 1 was a control group, i.e., basal diet + 0 g/day GAA; Group 2 was fed according to the feeding method in Example 1, i.e., basal diet + 5 g/day GAA; Group 3 was fed according to the feeding method in Example 2, i.e., basal diet + 10 g/day GAA; Group 4 was fed according to the feeding method in Example 3, i.e., basal diet + 20 g/day GAA; Group 5 was fed according to the feeding method in Example 4, i.e., basal diet + 40 g/day GAA. Each group had three replicates, and each replicate had three cattle.

[47] The pretrial period was 7 days, and the trial period was 45 days. During the trial, the cattle were fed with equal amounts of concentrate and roughage successively in twice at 7:00 a.m. and 17:00 p.m. every day and raised in tethered stalls, and had free access to drinking water. Before each feeding, accurately weighed GAA was mixed well with the concentrate. Mangers were cleaned up and the cowshed was cleaned every day.

[48] (2) Sample collection

[49] Feed samples: Three days before the trial ended, concentrates and roughages of the day were collected from each group, respectively; samples were taken back to the laboratory, dried in a 65°C oven to constant weight, taken out, and dampened at room temperature for 24 h to prepare air-dried samples; the feed samples were pulverized, sieved through a 40 mesh screen, and stored in valve bags for later use. Fecal samples: Three days before the feeding trial ended, three experimental cattle with similar body weight were selected from each group, and fecal samples were collected for three consecutive days; the fecal samples collected for three days were mixed well, taken back to the laboratory, dried in a 65°C oven to constant weight, pulverized, sieved through a 40 mesh screen, and stored in valve bags for later use; the fecal samples were stored in the laboratory and nutrients were analyzed.

[50] (3) Index detection

[51] Average dry matter intake (ADMI): Feed intake and residual feed intake of each experimental cattle were accurately weighed and recorded, and finally ADMI of each experimental cattle was calculated.

[52] Average daily gain (ADG): Prior to the trial period, each experimental cattle was weighed in the fasting state at 07:00 a.m. for two consecutive days, and the average was used as initial weight; after the whole trial ended, each experimental cattle was weighed in the fasting state at 07:00 a.m. for two consecutive days, and the average was used as final weight; ADG and feed-gain ratio (F/G) were calculated according to the average of two weights plus number of trial days.

[53] ADMI = Z(Fed dry matter intake - Residual dry matter intake)/Days of trial, Formula I;

[54] ADG = (Final weight - Initial weight)/Number of trial days, Formula II;

[55] F/G = ADMI/ADG, Formula III;

[56] Nutrients: In terms of both diet and feces, acid insoluble ash (AIA), dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), organic matter (OM), and crude ash (Ash) were determined with reference to methods described in the Feed Analysis and Quality Test Technology. V2 Ai

[57] Apparent digestibility of feed nutrients(%)= 100 - (/V- -A ) x 100, Formula IV;

[58] where: NI is the content of nutrients in the diet (g/g); N2 is the content of nutrients in the feces (g/g); Al is the content of indicator in the diet (g/g); A2 is the content of indicator in the feces

(g/g).

[59] (4) Data processing and statistical analysis

[60] The experimental data were preliminarily processed in Excel 2010 and subjected to one-way ANOVA using SPSS 20.0 software; when the difference was significant, multiple comparison was conducted by Duncan's multiple range test; results were expressed as mean standard error (SE); P < 0.05 was considered as significantly different. Multiple regression analysis was used for regression analysis.

[61] Experimental results

[62] 1) Effects of GAA on growth performance indices of beef cattle

[63] Table 1 Effects of GAA on growth performance indices of Jinjiang cattle Item Supplemental level of GAA SEM P value Group 1 Group 2 Group 3 Group 4 Group 5 Initial weight (kg) 350.7 350.7 350.7 349.6 350.7 4.55 1.000 Final weight (kg) 392.9 394.5 395.6 402.6 397.1 5.27 0.966 ADG (kg) 0.81b 0.99ab 0.94ab 1.09a 1.01a 0.03 0.047 ADMI (kg/day) 8.05 8.14 8.10 8.36 8.54 0.09 0.501 F/G 9.94a 8.23bc 8.61b 7.67c 8.47b 0.26 <0.001

[64] NOTE: Data on the same line, designated by different letters, indicate significant differences (P< 0.05), and those designated by the same or no letter indicate insignificant differences (P > 0.05), similarly hereinafter.

[65] From Table 1, there is no significant difference in initial weight between groups of beef cattle (P> 0.05) prior to the trial, and there is also no significant difference in final weight between groups of beef cattle (P> 0.05) after the feeding trial; compared with Group 1, the diets supplemented with g/day (Example 3) and 40 g/day (Example 4) GAA significantly increase the ADG of the beef cattle (P < 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the ADFI of the beef cattle (P > 0.05); compared with Group 1, the diets supplemented with g/day (Example 1), 10 g/day (Example 2), 20 g/day (Example 3), and 40 g/day (Example 4) GAA significantly decrease the F/G of the beef cattle (P < 0.05), where the 20 g/day GAA group (Example 3) achieves the best effect, which is significantly lower than other groups (P < 0.05).

[66] 2) Effects of GAA on the apparent digestibility of nutrients of the beef cattle

[67] Table 2 Effects of GAA on the apparent digestibility of nutrients

Item Supplemental level of GAA SEM P value Group Group2 Group3 Group4 Group5 DM(%) 67.40 67.64 68.18 70.23 67.50 4.68 0.245 OM(%) 71.76 72.41 72.53 74.41 71.86 4.52 0.293 CP(%) 74.55 74.77 74.60 76.90 75.06 5.71 0.739 NDF(%) 59.57 47.17 50.40 62.87 54.52 8.47 0.155 ADF(%) 50.12 50.07 49.15 56.77 49.95 8.31 0.873

[68] From Table 2, compared with Group 1, the diets supplemented with 5 g/day (Example 1), 10 g/day (Example 2), 20 g/day (Example 3), and 40 g/day (Example 4) GAA numerically increase the apparent digestibility of DM, OM, and CP of the beef cattle (all P > 0.05); compared with Group 1, the diet supplemented with 20 g/day (Example 3) GAA numerically increases the apparent digestibility of NDF and ADF (both P > 0.05), by 5.54% and 13.27%, respectively.

[69] Application Example 2

[70] Effects of diet supplemented with GAA on blood biochemical indices of beef cattle

[71] (1) Experimental design

[72] The experimental design was the same as that in Application Example 1.

[73] (2) Sample collection

[74] Each beef cattle was fasted for 12 h one day before the trial ended, and blood samples were collected; 15 mL of jugular blood was collected into a non-anticoagulant vacuum blood collection tube; the blood collection tube was placed on a slant for 30 min and centrifuged at 3,500 r/min for 10 min; the centrifuged serum was dispensed into 1.5 mL EP tubes and stored in a -20°C refrigerator for later use.

[75] (3) Index detection

[76] Detection of serum biochemical indices: Levels of blood glucose (GLU), total cholesterol (TC), triglyceride (TG), total protein (TP), albumin (ALB), high-density lipoprotein (HDL), and low density lipoprotein (LDL) in serum were detected by using the corresponding kits.

[77] Detection of serum antioxidant indices: Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in serum were detected by using the corresponding kits.

[78] (4) Data processing and statistical analysis

[79] Data processing and statistical analysis methods were the same as those in Application Example 1.

[80] Experimental results

[81] 1) Effects of GAA on beef cattle serum biochemical indices

[82] Table 3 Effects of GAA on Jinjiangcattle serum biochemical indices

Item Supplemental level of GAA SEM P value Group 1 Group 2 Group 3 Group 4 Group 5 GLU (mmol/L) 5.25a 4.34b 4.38b 4.52b 4.63b 0.12 0.046 TC (mmol/L) 2.76 2.62 2.23 2.48 2.47 0.12 0.780 TG (mmol/L) 0.24 0.22 0.20 0.23 0.17 0.02 0.650 TP (g/L) 77.93 79.23 79.53 78.30 80.27 1.04 0.214 ALB (g/L) 40.57 39.27 39.80 37.10 39.27 0.61 0.523 HDL (mmol/L) 2.43 2.28 1.94 2.13 2.18 0.11 0.765 LDL (mmol/L) 1.16 1.04 0.87 1.00 1.02 0.07 0.856

[83] From Table 3, compared with Group 1, the diets supplemented with GAA significantly decrease the level of GLU in beef cattle serum (P < 0.05), which is decreased by 17.33%, 16.57%, 13.90%, and 11.81% in Groups 2 to 5 compared with Group 1, respectively (all P < 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the level of TC in beef cattle serum (P > 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the level of TG in beef cattle serum (P> 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the level of TP in beef cattle serum (P> 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the level of HDL in beef cattle serum (P > 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the level of LDL in beef cattle serum (P> 0.05).

[84] 2) Effects of GAA on beef cattle serum antioxidant indices

[85] Table 4 Effects of GAA on Jinjiangcattle serum antioxidant indices

Item Supplemental level of GAA SEM P value Group 1 Group 2 Group 3 Group 4 Group 5 MDA (nmol/mL) 3.59 3.62 4.76 4.10 3.92 0.36 0.837 SOD (U/mL) 25.25d 33.18bc 39.06a 35.41ab 29.37cd 1.19 <0.001 T-AOC (U/mL) 4.87 4.77 4.70 4.22 4.31 0.15 0.603

[86] From Table 4, compared with Group 1, the diets supplemented with GAA have an insignificant effect on the level of MDA in beef cattle serum (P> 0.05); compared with Group 1, the diets supplemented with 5 g/day (Example 1), 10 g/day (Example 2), and 20 g/day (Example 3) GAA significantly increase the level of SOD in beef cattle serum (all P < 0.05), which is increased by 31.41%, 54.69, and 40.23%, respectively (all P < 0.05); compared with Group 1, the diets supplemented with GAA have an insignificant effect on the T-AOC in beef cattle serum (P> 0.05).

[87] Application Example 3

[88] Effects of diet supplemented with GAA on rumen fermentation of beef cattle

[89] (1) Experimental design

[90] The experimental design was the same as that in Application Example 1.

[91] (2) Sample collection

[92] On the day of completion of the feeding trial, five cattle with similar body weight were selected from Groups 1 to 5, respectively; before slaughter, the cattle were fasted, drank sufficient water, and rested well; after 24 h, the cattle were weighed to obtain pre-slaughter live weights; subsequently, the experimental cattle were transported to a slaughter room for slaughter; slaughter, inspection and quarantine were conducted according to the slaughtering process of the slaughter room; rumen fluids were collected immediately after slaughter, and filtered through 4 layers of gauzes; partial filtrates were cryopreserved at -20°C for the detection of ruminal fermentation parameters (pH, NH 3 -N, and VFA).

[93] (3) Index detection

[94] Measurement of pH: The rumen fluids filtered through four layers of gauzes were measured by a portable pH meter immediately after slaughter.

[95] Ammonia nitrogen (NH 3 -N) was detected by colorimetry with reference to the method provided by FENG Zongci et al. (1993).

[96] Ruminal microbial protein (MCP) was detected by the Coomasie brilliant blue staining method (ZINN, R.A et al., 1986); the content of MCP in the culture solution was detected by using 752 UV-Visible Spectrophotometer.

[97] Detection of rumen fluid volatile fatty acids (VFA): Using 2-ethylbutyric acid as an internal standard, VFA was detected by gas chromatography; 2 mL of rumen fluid was centrifuged at 5,000 xg for 10 min; 1 mL of supernatant was pipetted into a 2 mL centrifuge tube, mixed well with 0.2 mL of 25% metaphosphoric acid solution, and stored in a 4°C refrigerator overnight. The next day, the centrifuge tube was removed and centrifuged at 10,000 xg for 10 min; the supernatant was placed in a sample vial, and the content of total volatile fatty acids (TVFA) and various VFAs in the rumen fluid was determined by using Agilent 7890B Gas Chromatograph. Determination conditions were as follows: the detector temperature was 220°C, the column temperature was 180°C, the vaporization temperature was 200°C, highly pure nitrogen was used as a carrier gas, the pressure was 90 kPa, the total flow rate was 37.2 mL/min, the air flow rate was 400 mL/min, the hydrogen flow rate was 40 mL/min, the purge gas flow rate was 3 mL/min, the split ratio was 50:1, and the linear velocity was 23.4 cm/s.

[98] (4) Data processing and statistical analysis

[99] Data processing and statistical analysis methods were the same as those in Application Example 1.

[100] Experimental results

[101] 1) Effects of GAA on beef cattle ruminal fermentation parameters

[102] Table 5 Effects of GAA on Jinjiangcattle ruminal fermentation parameters Supplemental level of GAA Item SEM P Group 1 Group 2 Group 3 Group 4 Group 5 pH 6.88a 6.83b 6.68d 6.74c 6.77c 0.02 <0.001 NH3N (mg/dL) 6.54a 5.85b 5.54b 6.00b 6.12b 0.15 <0.001 Ruminal MCP (mg/L) 66.41b 66.55b 67.08ab 67.49a 67.24ab 0.14 0.078 TVFA (mmol/L) 71.32c 72.65c 73.24bc 78.06a 75.84ab 0.73 0.003 Acetic acid (mmol/L) 46.21c 46.71c 47.8lbc 49.95a 48.63ab 0.41 0.004 Propionic acid (mmol/L) 14.86b 15.05b 14.98b 16.21a 15.35b 0.16 0.026 Butyric acid (mmol/L) 10.14b 10.88b 10.57b 11.89a 11.86a 0.21 0.002 Acetic acid/propionic acid 3.22 3.10 3.08 3.08 3.17 0.02 0.211

[103] From Table 5, compared with Group 1, the diets supplemented with GAA have significant effects on rumen fluid pH and the content of NH 3 N, MCP, TVFA, acetic acid, propionic acid, and butyric acid; herein, the diet supplemented with 20 g/day GAA (Example 3) has the most significant effect, significantly increases the concentrations of MCP, TVFA, acetic acid, propionic acid, and butyric acid, and significantly decreases pH and the concentrations of NH 3 N.

[104] Application Example 4

[105] Effects of diet supplemented with GAA on the slaughter performance and meat quality

[106] (1) Experimental design

[107] The experimental design was the same as that in Application Example 1.

[108] (2) Sample collection

[109] Slaughtered beef carcass was split in half, two longissimus dorsi samples were collected between the 1 2 th and 1 3 th ribs of the left carcass; one sample (200 g) was stored in a -20°C refrigerator for conventional nutrient composition analysis of muscles; the other (500 g) was placed in a 4°C aging room, and the drip loss, cooking percentage, and shear force of the beef samples were measured after 24 h. Detection results are shown in Tables 6 and 7.

[110] (3) Index detection

[111] Carcass weight: After electrical stunning, each cattle was exsanguinated, the head, fur, hooves, tail, and offals were removed, the carcass was split along the median dorsal line, and either half carcass was weighed, respectively.

[112] Backfat thickness: The thickness of the subcutaneous fat (excluding the skin) between the 1 2 th and 1 3 th ribs on both sides of the left carcass and perpendicular to the back was measured by using a vernier caliper; each side was measured twice repeatedly, and an average of four measured values served as the backfat thickness.

[113] Loin eye area: A longissimus dorsi cross-section pattern between the 1 2th and 1 3 th ribs of the carcass was drawn on the transparent parchment paper, and the area of the pattern drawn was the loin eye area.

[114] Dressing percentage: (Carcass weight/Live weight*100). Formula V.

[115] Beef pH measurement: pH values of longissimus dorsi samples were measured by using a portable pH meter at 45 min post-mortem and 24 h after aging at 4°C, respectively. Each sample was measured thrice and averaged.

[116] Meat color measurement: The color of post-mortem loin eye was measured by using a colorimeter; the lightness (L*), redness (a), and yellowness (b) of each sample was recorded by the CIE standard colorimetric system. Each sample was measured thrice and averaged.

[117] Drip loss (calculation formula refers to Honikel 1998): Drip loss = [(Initial weight - Final weight)/Initial weight]*100%, Formula VI.

[118] Cooking loss (calculation formula refers to Honikel 1998): Cooking loss= [(Initial weight Final weight)/Initial weight]*100%, Formula VII.

[119] Shear force measurement: Each beef sample after measurement of cooking loss was trimmed into three 1*1*3 cm cutlets along the course of the muscle fiber, and the shear force was measured in the vertical direction of the muscle fiber using a meat tenderness tester. Each sample was measured six times and averaged.

[120] Determination of nutritional indices of the meat product: Moisture content conformed to GB/T9695.15-2008 Meat and Meat Products - Method for Determination of Moisture Content; proteins conformed to GB/T9695.11-2008 Meat and Meat Products - Methodfor Determination of Nitrogen Content; fats conformed to GB/T9695.7-2008 Meat and Meat Products - Method for Determinationof Total Fat Content.

[121] Table 6 Effects of GAA on the slaughter performance and carcass quality indices of Jinjiang cattle

Item Supplemental level of GAA SEM P Group 1 Group 2 Group 3 Group 4 Group 5 Pre-slaughter live weight (kg) 383.7b 385.5b 387.3b 396.Oa 390.9ab 9.11 0.031 Carcass weight/kg 192.9c 195.6bc 197.2bc 204.1a 200.4b 4.49 0.044 Dressing percentage % 50.67 50.74 50.91 51.54 51.28 0.00 0.372 Backfat thickness/cm 0.76 0.78 0.81 0.96 0.85 0.05 0.096 2 Loin eye area/cm 110.3c 112.3c 118.3bc 126.8a 120.6ab 3.93 0.006

[122] Table 7 Effects of GAA on longissimus dorsi quality indices of Jinjiang cattle Item Supplemental level of GAA SEM P Group 1 Group 2 Group 3 Group 4 Group 5 pH at 45 min 6.67 6.62 6.63 6.64 6.66 0.10 0.890 pH at 24 h 5.68 5.66 5.67 5.59 5.62 0.07 0.550 Lightness L* 30.81 30.25 29.34 29.97 29.66 0.56 0.952 Redness a* 13.38b 13.55b 14.38ab 15.07a 14.66ab 0.39 0.013 Yellowness b* 2.91 3.31 3.34 3.83 3.76 0.26 0.685 Drip loss % 1.56a 1.34ab 1.05b 0.76c 0.88c 0.11 0.026 Cooking loss % 20.15 20.36 20.68 21.81 21.33 1.16 0.516 Shear force kgf 2.96 2.94 2.86 2.70 2.77 0.17 0.480

[123] From the experimental data recorded in Tables 6 and 7, in terms of slaughter performance, the pre-slaughter live weight, the carcass weight, the dressing percentage, the backfat thickness, and the loin eye area increase in Groups 2 to 5 compared with Group 1; in terms of meat quality indices, the longissimus dorsi samples at 45 min post-mortem and 14 h after aging at 4°C show decreases in pH value, lightness L*, drip loss, and shear force and increases in redness a*, yellowness b*, and cooking loss in Groups 2 to 5 compared with Group 1; it is thus clear that the diet supplemented with GAA has significant effects on the slaughter performance and meat quality of the beef cattle compared with Group 1.

[124] Although the present disclosure has been disclosed as above in the preferred examples, the content thereof is not intended to limit the present disclosure. Any person skilled in the art can make alterations and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure should be subject to the protection scope defined by the claims.

Claims

WHAT IS CLAIMED IS:

1. A feed composition for improving production performance, slaughter performance, and meat quality of beef cattle, comprising individually packaged mixed concentrate and roughage; wherein the mixed concentrate comprises guanidineacetic acid and concentrate; the concentrate comprises the following components: 50-70% by weight of corn, 5-20% by weight of wheat bran, 10-40% by weight of soybean meal, 1% by weight of calcium bicarbonate, and 4% by weight of premix; based on 1 kg of premix, the premix comprises 150,000 IU of vitamin A, 320,000 IU of vitamin D, 3,000 IU of vitamin E, 3,200 mg of Fe, 1,500 mg of Mn, 2,000 mg of Zn, 650 mg of Cu, 35 mg of I, 10 mg of Se, 10 mg of Co, 130 g of Ca, and 30 g of P; the roughage comprises one or more of Pennisetum purpureum (elephant grass) silage, Pennisetum sinese silage, corn silage, peanut hay, corn stalk, and rice straw.