Introduction
The herbivorous animal husbandry
industry is undergoing the initial stage of transformation from "low
quality forage + high levels of concentrate" to "high quality forage
+ low levels of concentrate" mode in China. In the development of modern
herbivorous animal husbandry, the focus has been to reduce feed costs, increase
economic benefits, expand the use of forage resources, and improve forage
storage technology. A variety of forages such as alfalfa, oats, corn and sweet
sorghum forage have been widely planted for silage production, bringing forage
resource advantages to herbivorous livestock. The high-quality forages instead
of concentrate were encouraged in herbivore diets to overcome the shortcomings
such as occurrence of metabolic diseases, high feed costs, low nutrient
conversion efficiency and poor economic benefits caused by high-level
concentrate diets (Schwaiger et al. 2013; Touno et al. 2013; Alstrup
et al. 2016; Marques et al. 2016).
The needs of consumers for
high-quality and locally raised grass-fed beef have been paid attention to
(Marques et al. 2016). Previous studies have recommended beef cattle fed
with high-quality forage and a small number of concentrate (Vieira and
Fernández 2014) or use local by-products on the farm (Casasús et al.
2012) to improve the economic benefits of beef production and obtain quality
meat.
The carcass and meat quality of
ruminants is affected by many factors (Dannenberger et al. 2006), and of
these, diet is likely the foremost. The previous studies reported that bulls
could adapt to different feeding strategies without significant effect on
meat quality (Manni et al. 2018). Also, Alfaia et al. (2009)
considered that a high-forage diet had nutritional advantages for ruminants and
conducive for the activity of cellulose-decomposing bacteria, which synthesized
intermediate isomers, biohydrogenated intermediate isomers trans11-18:1
(t11-18:1) and cis9, trans11-18:2 (c9, t11-18:2)
and n-3 polyunsaturated fatty acid (PUFA) of meat.
In
this context, considering the importance of the cattle industry and forage
utilization needs of good beef as well as the continuous search for efficient
and low-cost feed method, we evaluated the effect of replacing corn
silage with various forage silage on slaughter performance and beef muscle
quality, providing scientific and effective guidance
for quality safety, and disease control of beef cattle. We hypothesized that beef cattle fed a TMR with various
combinations of silage and concentrate had no negative effects on carcass parameter and beef
quality compared with the corn silage on the diet.
Materials and Methods
This study was performed on basis of the
animal care and use protocol approved by the Institute of Ruminants of Lanzhou
University (China).
Experimental site
The experiment was
conducted from May 2017 to December 2017 in Dingxi City, Gansu Province, in
China. The experimental site (35°07'34" N, 104°59'23" E, altitude
1899 m) belongs to the typical place of the semi-arid and hilly region of the
Loess Plateau, with an average annual temperature range of 5.7 to 7.7°C,
frost-free period of 122 to 160 days, with an average annual rainfall range of
300 mm to 400 mm. The growing season for forage is short, only 120 to 180 days
of the year, and droughts are common. More than 3 million acres of artificial
forage were planted as alfalfa (Medicago sativa L.), corn (Zea mays
L.), oats (Avena fatua L.), and sorghum (Sorghum bicolor L.).
Experimental animals,
diets, and design
The thirty male
Simmental (440.5 ± 11.5 kg) were selected and randomly divided into two
treatments, each group consisting of fifteen animals. A total mixed ration
(TMR) with single corn silage + alfalfa hay + concentrate (CS), and TMR with
various silage (corn silage + oat silage + alfalfa silage) + wheat straw +
concentrate (VS) was used to feed the animals. The fifteen animals in each
group were fed in a 100-m2 housing unit, each animal was fed in an
individual pen, and was allowed access only to its individual ration. All
animals were fed twice daily (0700 and 1700 h) and water was supplied ad
libitum, feed considering 5 to 10% refusals. The period of 207 days
fattening trial was split into three stages as P1 (1 to 64 days), P2 (65 to 130
days), P3 (131 to 207 days), and the formulations were adjusted according to
the nutritional requirements of beef cattle at different growth stages using
the NRC guidelines (2000). During each fattening phase, the level of
concentrates in the diets increased from 52 to 61.75%, and finally to
69.35% in the CS diet, and from 38 to 42%, and finally to 50% in the VS
diet. Diet composition and nutritional levels are shown in Table 1 and 2.
Slaughter, carcass
measurement, and sample collection
Six bulls from each group were weighed as live BW after
12 h fast and slaughtered by the Islamic Halal way within 12 h at the end of
the experiment. The 12th and 13th ribs of the left
carcass were selected to measure the eye muscle area (EMA) and backfat
thickness (BFT). Longissimus lumborum (LL) was sampled from the
left side of the carcass. Four steaks were collected from each LL
sample, one for estimations of meat color and pH, the second piece for
measurement of cooking losses and followed by Warner-Bratzler shear force
(WBSF) determinations, the third piece for measurement of water loss rate in
muscle, and
the last piece for analysis of the routine
composition, fatty acids, and amino acids. All TMR diets were sampled 4
times a month (once a week) and stored at -20°C until mixed in units of one
fattening period. The content of fatty acids and amino acids were determined.
pH value and meat color measurements
The pH was determined at 45 min, 24 h, and 48 h
postmortem, by inserting a portable pH meter (Testo 205, TestoAG, Schwarzwald,
Germany) probe into the muscle. The meat color (L* = lightness, a*
= redness, b* = yellowness) was measured using a CM-2600d
spectrophotometer (Minolta CR-400, Japan) at 45 min postmortem. Each meat
sample was determined three times and the average value was taken as the final
value of pH and meat color.
Warner-Bratzler shear force, water holding capacity
measurements
The WBSF was determined using a meat tenderness tester
(RH-N50, Nanjing Xiyi Instrument equipment Co. Ltd, China) following the method
(Zhao et al. 2015) at 45 min postmortem. Briefly, the meat samples
were heated in a constant temperature water bath at 85°C. The samples were
taken out and cooled to room temperature after the central temperature reached
70°C. Then, the steak was cut into six cylindrical cores through a round
sampler (diameter = 1.27 cm) for WBSF measurement, the value of WBSF was the
average value after six measurements.
Table 1: Composition and
nutrient levels of experimental diets (DM basis)
|
Ingredients (DM/%) |
CS |
VS |
||||
|
P1 |
P2 |
P3 |
P1 |
P2 |
P3 |
|
|
Corn silage |
40.00 |
33.50 |
26.80 |
27.00 |
30.00 |
30.00 |
|
Oats silage |
15.00 |
14.00 |
10.00 |
|||
|
Alfalfa silage |
10.00 |
9.00 |
8.00 |
|||
|
Alfalfa hay |
8.00 |
4.75 |
3.85 |
|||
|
Wheat straw |
10.00 |
5.00 |
2.00 |
|||
|
Corn |
31.00 |
40.10 |
46.95 |
20.00 |
23.00 |
30.00 |
|
Bran |
9.00 |
6.00 |
6.00 |
9.00 |
6.00 |
6.00 |
|
Soybean meal |
3.00 |
4.30 |
4.30 |
1.00 |
2.00 |
2.00 |
|
linseed meal |
5.00 |
6.34 |
7.20 |
5.00 |
6.34 |
7.20 |
|
NaHCO3 |
0.80 |
1.09 |
1.00 |
0.80 |
1.09 |
1.00 |
|
CaHPO4 |
0.40 |
0.50 |
0.50 |
0.40 |
0.50 |
0.50 |
|
NaCl |
0.20 |
0.30 |
0.30 |
0.20 |
0.30 |
0.30 |
|
Premix1) |
2.50 |
3.10 |
3.10 |
2.50 |
3.10 |
3.10 |
|
Total |
100.00 |
100.00 |
100.00 |
100.00 |
100.00 |
100.00 |
|
Nutrient level |
||||||
|
ME (MJ/kg) |
13.34 |
14.07 |
14.46 |
13.32 |
14.07 |
14.45 |
|
CP (%) |
12.89 |
13.18 |
13.80 |
12.86 |
13.16 |
13.78 |
|
Ca (%) |
0.40 |
0.36 |
0.36 |
0.39 |
0.37 |
0.39 |
|
P (%) |
0.41 |
0.35 |
0.38 |
0.36 |
0.38 |
0.39 |
|
Neutral detergent fiber (%) |
32.77 |
27.62 |
24.08 |
38.90 |
29.30 |
25.45 |
|
Acid detergent fiber (%) |
17.39 |
13.96 |
11.63 |
19.61 |
15.07 |
13.60 |
CS group: trench-style corn silage, VS group: wrapped corn silage
Premix provided the following per
kg of the diet: VA 160 KIU, VD3 50 KIU, VE 900 IU, VB1
120 mg, nicotinic acid 500 mg, Fe 1200 mg, Cu 150 mg, Zn 1000 mg, Mn 500 mg
Table 2: Fatty acid and amino
acid content of experimental finishing diets fed to beef cattle during
different fattening phases
|
Parameter |
P1 |
P2 |
P3 |
|||
|
CS |
VS |
CS |
VS |
CS |
VS |
|
|
Fatty acid profile (g/kg) FAME1) |
|
|
|
|
|
|
|
C16:0 |
158.10 |
175.23 |
147.00 |
162.00 |
182.23 |
177.45 |
|
C18:0 |
110.80 |
77.30 |
121.20 |
80.34 |
118.00 |
95.56 |
|
C18:1 |
218.60 |
233.90 |
205.00 |
224.12 |
214.11 |
231.00 |
|
C18:2 |
528.00 |
522.00 |
524.11 |
516.34 |
509.00 |
518.70 |
|
C18:3 |
75.22 |
57.73 |
66.12 |
54.23 |
76.32 |
59.80 |
|
Amino acids (mg/g) |
|
|
|
|
|
|
|
Lysine |
6.12 |
8.40 |
8.76 |
8.78 |
9.02 |
8.98 |
|
Arginine |
5.72 |
9.67 |
10.45 |
10.12 |
10.44 |
10.89 |
|
Methionine |
2.12 |
3.02 |
2.27 |
2.34 |
2.67 |
2.56 |
|
Threonine |
5.02 |
5.24 |
5.78 |
5.68 |
6.01 |
6.12 |
|
Isoleucine |
0.55 |
0.58 |
0.57 |
0.51 |
0.66 |
0.61 |
|
Leucine |
1.01 |
0.81 |
0.82 |
0.79 |
1.00 |
0.96 |
|
Phenylalanine |
0.35 |
0.52 |
0.49 |
0.51 |
0.65 |
0.76 |
|
Aspartic acid |
10.70 |
9.67 |
10.23 |
10.26 |
11.23 |
11.21 |
|
Proline |
9.89 |
10.01 |
9.45 |
9.59 |
8.87 |
8.79 |
|
Histidine |
2.03 |
2.31 |
2.56 |
2.68 |
2.90 |
2.96 |
|
Cystine |
0.72 |
0.58 |
0.45 |
0.54 |
0.67 |
0.78 |
|
Valine |
4.27 |
4.34 |
3.98 |
4.06 |
3.86 |
3.69 |
|
Serine |
3.12 |
3.04 |
3.67 |
3.36 |
3.78 |
3.56 |
|
Glutamate |
11.20 |
11.56 |
11.03 |
11.23 |
10.76 |
10.91 |
|
Glycine |
2.13 |
2.02 |
1.89 |
1.87 |
2.04 |
2.45 |
|
Alanine |
1.23 |
1.34 |
1.45 |
1.61 |
1.56 |
1.76 |
|
Tyrosine |
1.81 |
1.73 |
1.92 |
1.88 |
2.02 |
2.00 |
CS group: TMR with single corn silage; VS
group: TMR with various silages (corn silage, alfalfa silage, and oat silage)
1) FAME = fatty acid methyl esters
For the cooking loss analysis at
45 min postmortem, 300 g of muscle was cooked in 85°C water bath to a 70°C
central temperature then the sample was taken out, blotted dry with filter
paper, and weighed again. The value of the cooking loss was the percentage of
weight change before and after cooking.
At 45 min postmortem, 3 × 3 × 1
cm meat slices were taken from the meat samples and weighed (W1). Then at room
temperature, 18 layers of neutral filter paper were put on the top and bottom
of the meat sample, and a 35 kg pressure was applied to the meat sample with a
meat quality hydraulic tester (RH-1000, Chongqing Corod Technology Co., Ltd.
China). After waiting for 5 min, the meat sample was taken out to weigh again
(W2), and calculated according to the following formula:
Water loss rate (%) = (W1-W2)/W1×100%.
Nutritional composition of beef muscle
The muscle fresh samples were brought back to the laboratory
for freeze-drying and ground into a powdered form for the test. Protein,
intramuscular fat (IMF), and ash contents of meat were analyzed following AOAC
(1995) method. The analyses were performed in triplicate.
The fatty acids (FA) were
extracted through the fatty acid methyl ester (FAME) synthesis modified
version method of O'Fallon et al. (2007). A 0.5 g desiccated sample was
put into a 10 mL glass tube with a stopper, 6.3 mL methanol solution (0.1
mol/L) and 0.7 mL KOH (10 mol/L) was added, and subjected to incubation in a
water bath for 90 min at 55°C, the glass tube was shaken for 5 s every 20 min.
After the water bath, the glass tube was taken out, cooled to room temperature,
and then 0.58 mL H2SO4 (12 mol/L) was added. The
glass tube was subjected to 55℃ for 90 min and shaken for 5 s every 20 min. After the second water
bath, the glass tube was taken out, cooled to room temperature, then added 3 mL
n-hexane, shaken, and transferred the solution to a centrifuge tube. Finally,
centrifuged at 3000 r/min for 5 min, then filtered the supernatant into a
sample bottle by the organic phase filter membrane, and placed at -20°C for GC
detection. The internal standard C19:0 methyl ester (standard no. N-21M, Nu-Chek, USA) was added to n-hexane (1 g/L) in advance. The 37
FAME Standards (Supelco, USA) and mixture standard of
conjugated linoleic acid (CLA) (Sigma-Aldrich Chemie, Germany) were used. The
FA analysis was performed by Agilent technologies 6890N gas chromatograph
(Thermo Scientific, TRACE, 1300, Milan, Italy). The chromatographic column
model is HP-88 (100 m × 0.25 mm × 0.20 μm, Agilent Technologies, USA),
compensation gas flow rate: 40.0 mL/min; flow rate of hydrogen: 35.0 mL/min;
air flow rate: 35.0 mL/min; detector temperature: 250°C; inlet temperature:
250°C; split ratio: 15:1. FA analysis was an automatic sampler and reference
fatty acid standard for retention time identification of individual FA.
The amino acids were determined
by the hydrochloric acid hydrolysis method. The desiccated sample was weighed
at 10 mg, and 10 mL HCl (6 mol/L) was added, then added 0.2 mL phenol solution,
vacuumed and filled with nitrogen, hydrolyzed at 110°C for 24 h, and then
filtered into 50 mL volumetric bottle. After vacuum drying, it was washed with
a small amount of deionized water. After steaming, 1 mL HCl was added (0.02
mol/L) and put through a 0.22-μm filter membrane. Hitachi 835-50 amino
acid automatic analyzer was used (Jiao et al. 2020). The ion-exchange
chromatographic column (650–0042, MembraPure, Bodenheim, Germany) was used,
where the amino acids were eluted by the natrium buffer system. After reacting
with ninhydrin, the derivatives were tested at 570 nm.
Muscle histological properties
The three pieces muscle (1 × 1 × 1 cm) of each sample was
fixed in 4% formalin and stained using the hematoxylin-eosin (HE) staining
method to make sections (Wang et al. 2009). After the slices were
prepared, it was observed with a microscope (ScopeIm-age 9.0) at 4 × 10
magnification and stored for photos. For the measurement method of muscle fiber
diameter, area, and density referenced to Wang et al. (2018). Briefly,
three areas were selected randomly from each sample, and not less than 300
roots muscle fibers were observed, 30 roots muscle fibers were randomly
measured for muscle fiber diameter and muscle fiber area. ScopeIm-age 9.0 was
used to measure the long and short diameters of muscle fiber cross-sections,
both the geometric mean was regarded as the muscle fibers diameter, and the
muscle fibers area of the cross-section was directly measured. The number of
muscle fibers in each visual field was measured, and a final, converted to the number
of roots per square millimeter to serve as the muscle fiber density of the
sample.
Statistical analysis
Statistical analysis was performed by independent sample
t-test with S.P.S.S. (v. 19.00). The
normality test is carried out before the test, and further analysis can be
carried out after the normality is satisfied. Each animal was taken as the
experimental unit, P-value of 0.05 as the significance criterion.
Results
Slaughter performance of beef cattle
As expected, the slaughter BW, carcass weight, slaughter
rate, and BFT of the Simmental were similar between the two groups (Table 3). The
EMA was significantly greater in the VS group (149.59 cm2) compared
with the CS group (137.87 cm2) (P
< 0.05) (Table 3).
Table 3: Slaughter
performance of beef cattle fed TMR with various forage silage (n = 6 per group)
|
Parameter |
Groups |
|
|
CS |
VS |
|
|
Slaughter BW1)
(kg) |
723.94 ± 14.73 |
730.50 ± 11.10 |
|
Carcass weight (kg) |
415.18 ± 8.89 |
422.50 ± 6.99 |
|
Slaughter rate (%) |
57.35 ± 0.69 |
57.84 ± 0.32 |
|
Backfat thickness (mm) |
10.53 ± 0.96 |
10.55 ± 1.08 |
|
Eye muscle area (cm2) |
137.87 ± 16.55b |
149.59 ± 4.10a |
CS group: TMR with single corn silage;
VS group: TMR with various silages (corn silage, alfalfa silage, and oat
silage)
1) BW: body weight
a,
b
Means with different superscript letters in the same row differ from each other
(P < 0.05)
Table 4: Effects of TMR with
various forage silage on meat quality of Longissimus lumborum from
fattening beef cattle (n = 6 per group)
|
Parameter |
Groups |
||
|
CS |
VS |
||
|
Meat color |
L* (lightness) |
30.95 ± 1.62 |
29.15 ± 0.73 |
|
a* (redness) |
7.54 ± 1.09 |
6.50 ± 0.46 |
|
|
b* (yellowness) |
9.20 ± 1.80 |
7.80 ± 0.51 |
|
|
pH |
0 h |
6.01 ± 0.11 |
5.93 ± 0.13 |
|
24 h |
5.57 ± 0.19 |
5.54 ± 0.22 |
|
|
48 h |
5.41 ± 0.13 |
5.48 ± 0.17 |
|
|
Water loss rate (%) |
5.09 ± 0.56 |
5.89 ± 0.51 |
|
|
Cooked meat rate (%) |
61.94 ± 0.26 |
62.83 ± 0.19 |
|
|
Shearing force (N) |
58.86 ± 0.09 |
58.24 ± 0.15 |
|
CS group: TMR with single corn silage;
VS group: TMR with various silages (corn silage, alfalfa silage, and oat
silage)
Table 5: Effect of TMR with various
forage silage on the chemical composition of muscle (Longissimus lumborum)
from fattening beef cattle (n = 6 per group) (DM basis, %)
|
Groups |
||
|
CS |
VS |
|
|
Protein |
76.84 ± 0.99 |
77.13 ± 0.89 |
|
Intramuscular fat |
7.15 ± 0.49 |
6.14 ± 0.54 |
|
Ash |
4.41 ± 0.04 |
4.34 ± 0.04 |
CS group: TMR with single corn silage;
VS group: TMR with various silages (corn silage, alfalfa silage, and oat
silage)
Meat quality of beef cattle
Table 4 showed that neither treatment nor acid drainage
time showed significant differences in muscle pH value. We found that the shear
force values were not significantly different between the two groups. The type
of diets did not affect the WHC of beef muscle. No difference was observed in the cooking
loss of beef between the two groups in the present study. And more, the L*
(lightness), a* (redness), and b* (yellow) chromaticity of meat were not
influenced by diet composition.
Nutrient content, fatty acid profile, amino acid
composition of the longissimus lumborum
Nutrient content: There were no
significant differences in the protein, IMF, and ash content between the two
groups (P > 0.05), however, the
content of IMF was 6.14 and 7.15% in the VS group and CS group, respectively
(Table 5).
Fatty acid profile: The diet
treatment did not significantly affect the fatty acid composition of the muscle
(Table 6). The main fatty acid included palmitic (C16:0), stearic (C18:0), and
octadecenoic (C18:1n9c) acids, which together accounted for 75.27% of the total
fatty acids. The main intermediate products of rumen biohydrogenation were trans-vaccenic
acid (C18:1n9t), vaccenic acid (C18:1n9c), linolelaidic acid (C18:2n6), conjugated linoleic acids (CLA), and
linolenic acid (C18:3n3), which accounted for 44.89 and 47.04% of the total fatty acids in the
CS and VS groups respectively. The CLA which have great benefits for human
health was 0.25 and 0.32% in the CS and VS groups respectively. Overall, the
saturated fatty acid (SFA) was 47.41% in the CS vs. 45.44% in the VS group of
the total fatty acids, the monounsaturated fatty acids (MUFA) were 39.40% in
the CS vs. 40.02% in the VS group,
and polyunsaturated fatty acids (PUFA) were 12.94% in the CS vs. 14.23% in the VS group. Within PUFA,
the n-6: n-3 PUFA were 3.32 and 3.02 in the CS and VS group, respectively. Likewise,
the ratio of P/S was 0.27 and 0.31 in the CS and VS group.
Amino acid composition: There were no significant differences in the contents of amino acids,
which are essential amino acid (EAA), nonessential amino acid (NEAA), delicious
amino acid (DAA), and functional amino acid (FAA) between the two groups,
except histidine (P > 0.05). The content of histidine in the VS group was
significantly higher than that in the CS group (P < 0.05). The content of
EAA was 41.54 and 42.62% in the CS group and VS group respectively. The ratio
of Table 6: Effect of TMR with various forage silage on the fatty acid
profile (mg/g, DM basis) of muscle (Longissimus lumborum) from fattening
beef cattle (n = 6 per group)
|
Parameter |
Groups |
|
|
CS |
VS |
|
|
∑Fatty acids
(mg/g) |
100.21 ± 2.56 |
92.79 ± 2.16 |
|
C10:0 |
0.64 ± 0.06 |
0.60 ± 0.07 |
|
C12:0 |
0.59 ± 0.05 |
0.48 ± 0.04 |
|
C14:0 |
2.22 ± 0.10 |
1.90 ± 0.09 |
|
C14:1 |
0.27 ± 0.01 |
0.29 ± 0.01 |
|
C15:0 |
0.34 ± 0.02 |
0.30 ± 0.02 |
|
C16:0 |
25.32 ± 0.15 |
22.77 ± 0.17 |
|
C16:1 |
3.14 ± 0.16 |
2.66 ± 0.14 |
|
C17:0 |
1.33 ± 0.10 |
1.13 ± 0.11 |
|
C17:1 |
0.65 ± 0.05 |
0.52 ± 0.04 |
|
C18:0 |
16.88 ± 0.16 |
14.90 ± 0.18 |
|
C18:1n9t |
1.81 ± 0.12 |
1.67 ± 0.09 |
|
C18:1n9c |
33.42 ± 0.26 |
31.99 ± 0.23 |
|
C18:2n6t |
2.37 ± 0.11 |
2.11 ± 0.10 |
|
C18:2n6c |
5.85 ± 0.07 |
5.64 ± 0.09 |
|
CLA |
0.45 ± 0.06 |
0.30 ± 0.01 |
|
C18:3n3 |
1.91 ± 0.06 |
1.94 ± 0.08 |
|
C20:0 |
0.09 ± 0.01 |
0.08 ± 0.01 |
|
C20:1 |
0.12 ± 0.02 |
0.12 ± 0.02 |
|
C20:3n6 |
0.68 ± 0.03 |
0.61 ± 0.01 |
|
C20:4n6 |
1.74 ± 0.09 |
1.56 ± 0.12 |
|
C20:5n3 |
0.67 ± 0.03 |
0.65 ± 0.01 |
|
C22:5n3 |
0.71 ± 0.04 |
0.69 ± 0.02 |
|
∑SFA |
47.41 ± 1.26 |
42.16 ± 1.16 |
|
∑MUFA |
39.41 ± 0.76 |
37.13 ± 0.87 |
|
∑PUFA |
12.94 ± 0.56 |
13.20 ± 0.56 |
|
n-6/n-3PUFA |
3.32 ± 0.02 |
3.02 ± 0.06 |
|
P/S |
0.27 ± 0.04 |
0.31 ± 0.03 |
CS group: TMR with single corn silage;
VS group: TMR with various silage (corn silage, alfalfa silage, and oat
silage).
CLA: cis-9. trans-11
conjugated linoleic acid
SFA: Saturated fatty acid
MUFA: Monounsaturated fatty
acids
PUFA: Polyunsaturated fatty
acids
P/S: Polyunsaturated fatty
acids/ Saturated fatty acid
EAA/NEAA in the two groups was about 0.91 (Table 7).
Also, the content of TAA and the percentage of each amino acid in the VS group
were higher than that in the CS group.
Muscle histological properties
The diameter of muscle fiber was greater for the VS
group compared to the CS group (P = 0.04), and connective tissue content was
lower (P = 0.05) (Table 8; Fig. 1).
Discussion
Carcass weight is an individual trait influenced by
factors such as heredity, breeding method, live weight before slaughter, and
market time (Petit 2005). The slaughter rate should be more than 55%, and was
larger in beef cattle when the BW is more than 600 kg before slaughter,
consistent with the results of this study. Back fat is an important parameter
to reflect fat deposition, as a higher back fat was negatively related to the
lean meat percentage. Lerch et al. (2015) found that the BFT of beef
cattle was greatly affected by breed. In the present study, the experimental
animals were Simmental; the BFT had no significant difference between the two
groups. Besides, there is a positive correlation between EMA, as a growth
index, and meat production performance, and lean meat percentage. In the
present study, the EMA in the VS group was higher compared with the CS group;
illustrating that TMR with various forage silage might be beneficial for
increasing meat yield. It should be related to the VS group increased dry
matter intake with an increase in roughage proportion compared with the CS
group. Further studies should analyze the relationship between the forage ratio
and meat yield.
Neither treatment nor acid drainage time showed
significant differences in muscle pH, which was consistent with previous
studies (Blanco et al. 2018), only a steady decrease in meat pH was
observed in both groups. The final pH value (5.41 and 5.48 for CS group and VS
group respectively) is range from 5.4 to 5.6 after slaughter 72 h within the
normal range (Judge et al. 1988). In the present study, the shear force
value (approximately 58.6 N) indicated that the meat not be called tender meat
with a shear force value equal to or less than 40 N (Perry et al. 2001).
Meat tenderness is affected by many factors, Table 7: Effect of TMR with
various forage silage on the total amino acid profile of muscle (Longissimus
lumborum) from fattening beef cattle (n = 6 per group) (DM basis)
|
Parameter |
Groups |
|
|
CS |
VS |
|
|
Essential |
|
|
|
Threonine (%) |
4.41 ± 0.09 |
4.54 ± 0.04 |
|
Valine (%) |
4.66 ± 0.08 |
4.76 ± 0.05 |
|
Methionine (%) |
0.84 ± 0.05 |
0.78 ± 0.08 |
|
Phenylalanine (%) |
3.75 ± 0.08 |
3.84 ± 0.03 |
|
Isoleucine (%) |
4.49 ± 0.09 |
4.59 ± 0.04 |
|
Leucine (%) |
7.82 ± 0.16 |
8.05 ± 0.07 |
|
Lysine (%) |
5.60 ± 0.12 |
5.76 ± 0.05 |
|
Histidine (%) |
3.88b ± 0.05 |
4.09a ± 0.04 |
|
Arginine (%) |
6.10 ± 0.12 |
6.23 ± 0.07 |
|
Nonessential |
|
|
|
Aspartic acid (%) |
8.93 ± 0.17 |
9.22 ± 0.09 |
|
Serine (%) |
15.99 ± 0.40 |
16.40 ± 0.19 |
|
Glutamate (%) |
3.65 ± 0.07 |
3.76 ± 0.04 |
|
Proline (%) |
3.65 ± 0.07 |
3.68 ± 0.06 |
|
Glycine (%) |
4.23 ± 0.06 |
4.31 ± 0.10 |
|
Alanine (%） |
5.51 ± 0.09 |
5.63 ± 0.05 |
|
Tyrosine (%) |
3.00 ± 0.05 |
3.09 ± 0.03 |
|
Cystine (%) |
1.82 ± 0.03 |
1.85 ± 0.01 |
|
Total AA (mg/g) |
868.10 ± 16.56 |
887.11 ± 9.12 |
|
Limited Amino Acids
(%) |
6.44 ± 0.13 |
6.53 ± 0.12 |
|
Essential amino acids
(%) |
41.54 ± 0.79 |
42.62 ± 0.43 |
|
Taste amino acids (%) |
41.60 ± 0.83 |
42.56 ± 0.50 |
|
Functional amino acids
(%) |
29.91 ± 0.68 |
30.67 ± 0.33 |
|
EAA/NEAA |
0.91 ± 0.04 |
0.91 ± 0.05 |
CS group: TMR with single corn silage;
VS group: TMR with various silages (corn silage, alfalfa silage, and oat
silage)
AA: amino acid;
EAA/NEAA: essential amino
acid/nonessential amino acid
a,
b
Means with different superscript letters in the same row differ from each other
(P < 0.05)
Table 8: Effects of histological
characteristics of lion-eye muscle beef cattle fed TMR with forage silage (n = 6
per group) (4 × 10 μm)
|
Parameter |
Groups |
|
|
CS |
VS |
|
|
Diameter of muscle fiber (μm) |
25.24b ±
0.56 |
30.00a ±
1.01 |
|
Area of muscle fiber (μm2) |
557.14 ± 2.06 |
812.79 ± 1.56 |
|
Density of muscle fiber (mm-2) |
1109.10 ± 10.06 |
1070.43 ± 9.56 |
|
Connective tissue content (%) |
41.21a ±
0.96 |
29.23b ±
1.16 |
CS group: TMR with single corn silage;
VS group: TMR with various silages (corn silage, alfalfa silage, and oat
silage)
a,
b Means
with different superscript letters in the same row differ from each other (P < 0.05)
%20895-903_files/image002.png)
Fig. 1a, b: Histological
characteristics of beef muscle
CS group: TMR with single corn silage;
VS group: TMR with various silages (corn silage, alfalfa silage, and oat
silage)
M: Muscle fibers
C: Connective tissue
including diet, age, growth
rate, and length of fattening period (Campo et al. 2008). Previous
reports indicated that beef tenderness decrease with the length of the
fattening time (French et al. 2000). Probably, the animals are fed for a
relatively long period to obtain greater slaughter weight, may help explain greater
shear force values in the present study.
The water holding capacity (WHC)
of meat may be influenced by the rate and extent of pH descends (Oliveira et
al. 2018). In the present study, the type of diets did not affect the WHC
of beef muscle, possibly due to a lack of significant differences in the
final pH of the meat. Additionally, there was a negative correlation
between WHC and the water loss rate of meat. According to Luciano et al. (2009)
and Schafer et al. (2002), the loss of water on the meat could decrease
the heme content in the muscle, affecting the superficial color and weight of
the meat, and reducing the economic benefit.
The lower the cooking loss, the
less loss of protein and fat, and the higher the nutritional value of the
muscle (McKenna et al. 2005). No difference was observed in the cooking
loss of beef between the two groups in the present study. Similarly, Wales et
al. (1998) and Dewhurst et al. (2009) also reported that, little
evidence was known as diet composition influenced cooked meat percentage.
The meat color may be affected
by diet, especially grass-fed (Priolo et al. 2001). Meat color is not
only related to intramuscular fat content, muscle pH value, animal age, and
carcass weight (Priolo et al. 2001), but also changes when beef is
oxidized by air (Liu et al. 1995). In this study, the L* (lightness), a*
(redness), and b* (yellow) chromaticity of meat were not influenced by diet
composition. The study results are consistent with previous findings that
forage itself had little effect on muscle color (Duckett et al. 2007, 2013).
Our findings may also be due to the fact that most factors affecting meat color
are not affected by dietary treatment.
Kobayashi et al. (2012)
reported that IMF in the muscle was positively related to the level of dietary
concentrate level. Similarly, the IMF content was higher in the muscle of
cattle fed with concentrate than cattle fed with roughage (Dannenberger et
al. 2004). Thus, differences in the ratio of concentrate could lead to
differences in the IMF content.
The composition of fatty acid affects
the health of meat, and is closely related to the flavor, tenderness, and
juiciness of the meat (Fisher et al. 2000). The World Health
Organization (WHO) (2003) indicates that the nutritional value of beef is
positively correlated with the PUFA ratio, especially the n-3 PUFA ratio.
Researchers generally believed that fatty acid composition was significantly
affected by diet factors (Enser et al. 1998; Scollan et al. 2001;
Dannenberger et al. 2004; Nuernberg et al. 2005). French et al.
(2000) found that fatty acid composition in beef could be improved by adding
forage in the diet. According to Yu et
al. (1995); Wood et al. (2004), compared with concentrate-based
feeding method, forage feeding could affect some meat quality indicators,
including meat color, flavor, and fatty acid composition. Previous studies'
results showed that the n-6: n-3 PUFAs were higher in some high-concentrate
diets, while that of livestock mainly fed forage was only about 1.2 (Joy et
al. 2014; French 2000). The n-6: n-3 PUFAs ratio of 4:1 is recommended by
the WHO in a healthy diet (2003). The present study showed that the n-6: n-3
PUFAs of the two groups was 3.32 (CS) and 3.02 (VS) respectively, which were
close to the recommended value. The WHO (2003) recommended that PUFA/SFA (P/S)
should be higher than 0.40. In this experiment, the ratio of P/S (average 0.30)
was lower than 0.40, which was still far from the reasonable nutritional
recommendation value of 0.40. As
has been also
reported the generality of livestock products for the P/S lower
than 0.40, which was necessary to devote ourselves to producing high-quality
livestock products in the future.
The amino acid is the basic unit
of protein, and important indicators for evaluating the nutritional value of
protein, which directly affects the nutritional value of beef (Ludden and
Kerley 1998; Gan et al. 2010). The EAA (lysine, threonine, leucine,
isoleucine, valine, methionine, tryptophan, phenylalanine, etc.) are the basic indicators for assessing the bioavailability of
proteins. They are important nutritional and physiological effects that can
only be obtained from outside the body. Histidine and arginine are
semi-essential amino acids in the human body, which cannot meet the needs of
the human body, and need to be taken from food, acting on the regulation of
metabolism, dilated blood vessels, cut down blood pressure (O'Connor et al.
1993; Semba et al. 2016). The DAA includes glycine, glutamate, alanine,
and aspartic acid, their content influences the degree of freshness to some extent
(Li et al. 2001).
The content of histidine in the
VS group was significantly higher than that in the CS group, indicating that
increase with the content and type of silage forage in the diet could
potentially reduce the negative effect. The content of EAA was 41.54 and 42.62%
in the CS group and VS group, respectively, which are close to the ideal amino
acid value (40%). The ratio of EAA/NEAA in the two groups was about 0.91, which
was greater than the recommended value (approximately 0.6) of FAO (1973),
indicated that the two groups diet from this study produces relatively
nutritious meat. Thus, the content of amino acid in the VS group was more
likely to approach or exceed the corresponding content of amino acid in the
ideal protein, which may be beneficial to improve the utilization of protein in
the human body, resulting from the overall interaction effect between nutrients
in different feeds combinations.
Previous studies had shown that
the histological characteristics of muscle fibers determined meat quality and
were closely related to food quality traits (Zeng et al. 1999). The
muscle fibers could be affected by the nutritional status, breed, age, and
athletic ability of the animal. Guo and Li (2008) showed that muscle fibers
were related to the shear force and tenderness of muscle. Also, the muscle
fiber diameter of meat products was negatively correlated with muscle fiber
density. There was a positive correlation between the diameter of muscle fibers
and the slaughter rate and eye muscle area for the same species (Li et al.
2017). Zhao and Yang (2003) showed that muscle fiber area increased with an
increase of the diet nutrient levels in pigs of the same weight. Also, Swatland
(1997) found that the structural distribution and content of connective tissue
are related to water loss and muscle succulence. Hence, the results of this
study indicate that diets with various silage matchings, a small number of
concentrates in beef cattle can improve muscle fiber, and thus meat quality.
Conclusion
Beef cattle can be fed TMR including corn silage, or a
mixture of corn silage, alfalfa silage, and oat silage during the fattening
stages with little difference in beef quality. A TMR
based on various forage silages can improve eye muscle area of beef cattle, increase
histidine content in muscle, and diameter of muscle fiber. Furthermore,
connective tissue content of the VS group was lower compared with the CS group.
In conclusion, substituting corn silage with various forage silages in the diet
for beef cattle could be a feasible strategy to raise fattening beef cattle in
the intensive feedlot system.
Acknowledgments
We thank the support from National Key R&D Program of China (No. 2017YFE0104300), the Second
Tibetan Plateau Scientific Expedition and Research (STEP) program
(2019QZKK0302), and Dingxi City Science and Technology Plan (071100032).
We gratefully acknowledged Prof. An
Jizhong, Mr. Wang Weizhong, Ms. Ma Peilin, and all staff of the Jia Tianxia
beef cattle farm in Dingxi City, Gansu Province for their help. We also thank
Ali Sher Bacha for guidance on English correction.
Author Contributions
Hu-Cheng Wang conceptualized the work and provided
laboratory facilities for analyzing and financial support; Xia Zhang collected
and analyzed the data, and visualized the results; Xia Zhang and Mahaboubil-haq
Muhaiden wrote and edited the paper.
Conflict of Interest
There is no conflict of interest among the authors and
institutions where the research has been conducted
Data Availability Declaration
Primary and supplementary data reported in this article
are available with the corresponding authors
Ethics Approval
This study involving animals
was reviewed and approved by the Institutional Animal Care and Use Committee of
the author(s). Animals were humanely sacrificed as necessary to ameliorate
suffering. Procedures were performed in accordance with the ARRIVE guidelines
available at: PLoS Bio 8(6), e1000412,2010
(authors are strongly encouraged to carefully read these guidelines)
References
Alfaia CPM,
SP Alves, SIV Martins, ASH Costa, CMGA Fontes, JPC Lemos, JAM Prates (2009).
Effect of the feeding system on intramuscular fatty acids and conjugated
linoleic acid isomers of beef cattle, with emphasis on their nutritional value
and discriminatory ability. Food Chem 114:939‒946
Alstrup L, K Söegaard, MR Weisbjerg (2016). Effects of
maturity and harvest season of grass-clover silage and forage-to-concentrate
ratio on milk production of dairy cows. J Dairy Sci 99:328‒340
AOAC (1995). Official Methods of Analysis, 16th edn.
Association Official Analytical Chemists, Arlington, Virginia, USA
Campo MD, G Brito,
JMSD Lima, DV Martins, C Sañudo, RS Julián, F Montossi (2008). Effects of
feeding strategies including different proportion of pasture and
concentrate, on carcass and meat quality traits in Uruguayan steers. Meat
Sci 80:753‒760
Casasús G Ripoll, P Albertí
(2012). Use of maize silage in beef heifers fattening diets: Effects on
performance, carcass, and meat quality. Inform Technol Econ Agrar 108:191‒206
Dannenberger D, K Nuernberg, G Nuernberg, K Ender (2006). Carcass and meat
quality of pasture vs. concentrate
fed German Simmental and German Holstein bulls. Arch Anim
Breed 49:309‒414
Dannenberger D, G Nuernberg, W Schabbel, H Steinhart, K Ender, K Nuernberg
(2004). Effect of diet on the deposition of n-3 fatty acids, conjugated
linoleic and C18:1 trans fatty acid isomers in muscle lipids of German Holstein
bulls. J Agric Food Chem 52:6607‒6615
Dewhurst RJ, L Delaby, A
Moloney, T Boland, E Lewis (2009). Nutritive value of forage legumes used for
grazing and silage. Irish J Agric Food Res 48:167‒187
Duckett SK, JP Neel, RM Lewis, JP Fontenot, WM Clapham
(2013). Effects of forage species or concentrate finishing on
animal performance, carcass, and meat quality. J Anim
Sci 91:1454‒1467
Duckett SK, JPS Neel, RNJ Sonon,
P Fontenot, WM Clapham, G Scaglia (2007). Effects of winter stocker
growth rate and finishing system on: II. Nineteenth-eleventh rib
composition, muscle color, and palatability. J Anim Sci 85:2691‒2698
Enser M, KG Hallett, B
Hewett, GAJ Fursey, JD Wood, G Harrington (1998). Fatty acid content and
composition of UK beef and lamb muscle in relation to production system and
implications for human nutrition. Meat Sci 49:329‒341
FAO (1973). Energy and Protein Requirements. Food
and Agriculture Organization of the United Nations and the World Health
Organization, FAO Food and Nutrition
Fisher AV, M Enser, RI
Richardson, JD Wood, GR Nute, E Kurt, RG Wilkinson (2000). Fatty acid
composition and eating quality of lamb types derived from four diverse breed × production
systems. Meat Sci 55:141‒147
French P (2000). Fatty acid composition, including
conjugated linoleic acid, of intramuscular fat from steers offered grazed
grass, grass silage, or concentrate-based diets. J Anim Sci 78:2849‒2855
French P, EG O'Riordan, FJ Monahan, PJ Caffrey, M
Vidal, MT Mooney, AP Moloney (2000). Meat quality of steers finished on
autumn grass, grass silage or concentrate-based diets. Meat Sci 56:173‒180
Gan CI, SS Guo, JH Rong, SB Xiong (2010). Analysis of
the main nutritional components of crisp meat sole muscle. J Nutr 32:513‒515
Guo Y, B Li (2008). Study on physico-chemical
properties and meat qualities of different parts of small-tail han sheep carcass. Food Sci 29:143‒147
Jiao J, T Wang, J Zhou, AA Degen, N Gou, S Li, Y Bai, X
Jing, W Wang, Z Shang (2020). Carcass parameters and meat quality of Tibetan
sheep and Small‐tailed Han sheep consuming diets of low‐protein
content and different energy yields. J Anim Physiol Anim Nutr104:1010–1023
Joy M, R Ripoll-Bosch, A Sanz, F Molino, I Blasco, J Álvarez-Rodríguez
(2014). Effects of concentrate supplementation on forage intake, metabolic
profile and milk fatty acid composition of unselected ewes raising lambs. Anim
Feed Sci Technol 187:19‒29
Judge MD, ED Aberle, JC Forrest, RA Merkel (1988). Principles
of Meat Science. Kendall Hunt Publishing Company, Iowa, USA
Kobayashi H, A Ishida, A Ashihara, K Nakashima, M
Katsumata (2012). Effects of dietary low level of threonine and lysine on the
accumulation of intramuscular fat in porcine muscle. Biosci Biotechnol
Biochem 76:2347‒2350
Lerch S, JAA Pires, C Delavaud, KJ Shingfield, D Pomiès,
B Martin, A Ferlay (2015). Rapeseed or linseed in dairy cow diets over 2
consecutive lactations: Effects on adipose fatty acid profile and carry-over
effects on milk fat composition in subsequent early lactation. J Dairy Sci
98:1005‒1018
Li K, Y Chen, C Moran, B Fan, S Zhao (2001). Analysis of
diversity and genetic relationships between four Chinese indigenous pig breeds
and Australian commercial pig breed. Anim Genet 31:322‒325
Li XJ, CX Liu, KL Yang, MJ Liu (2017). Study on
differentiation of fetal skeletal muscle development characteristics between
German and Chinese merino sheep. Grass-feed Livest 4:1‒6
Liu Q, MC Lanari, DM Schaefer
(1995). A review of dietary vitamin E supplementation for improvement of beef
quality. J Anim Sci 73:3131‒3140
Luciano G, FJ Monahan, V Vasta, L Biondi, M Lanza, A
Priolo (2009). Dietary tannins improve lamb meat color stability. Meat Sci
81:120‒125
Ludden PA, MS Kerley (1998). Amino acid and energy
interrelationships in growing beef steers: Effects of energy intake and
metabolizable lysine supply on growth. J Anim Sci 76:3157‒3168
Marques RS, LJ
Chagas, FN Owens, FAP Santos (2016). Effects of various
roughage levels with whole flint corn grain on performance of finishing cattle.
J Anim Sci 94:339‒348
McKenna DR, PD Mies, BE Baird, KD Pfeiffer, JW
Ellebracht, JW Savell (2005). Biochemical and physical factors affecting
discoloration characteristics of 19 bovine muscles. Meat Sci 70:665‒682
NRC (2000). Nutrient
requirements of beef cattle 7th edn.
National Academy Press, Washington DC, USA
Nuernberg K, D Dannenberger, G Nuernberg, K Ender, J Voigt, ND Scollan, RI
Richardson (2005). Effect of a grass-based and a concentrate feeding system on
meat quality characteristics and fatty acid composition of longissimus muscle
in different cattle breeds. Livest Prod Sci 94:137‒147
O'Connor JD, CJ Sniffen, DG
Fox, W Chalupa (1993). A net carbohydrate and protein system for evaluating
cattle diets: iv. Predicting amino acid adequacy. J Anim Sci 71:1298‒1311
O'Fallon JV, JR Busboom, ML Nelson, CT Gaskins (2007). A
direct method for fatty acid methyl ester synthesis: Application to wet meat
tissues, oils, and feedstuffs. J Anim Sci
85:1511–1521
Oliveira PPA, RRS Corte, SL Silva, PHM Rodriguez, LS Sakamoto, AF Pedroso, RR Tullio, A Berndt (2018). The effect of grazing system
intensification on the growth and meat quality of beef cattle in the Brazilian
Atlantic Forest biome. Meat Sci 139:157‒161
Perry D, JM Tompson, IH Wang,
A Butchers, A Ean (2001). Relationship between objective measurements and taste
panel assessment of beef quality. Aust J Exp Agric 41:981‒989
Petit HV (2005). Digestion, milk production, milk
composition, and blood composition of dairy cows fed whole flaxseed. J Dairy
Sci 85:1482‒1490
Priolo A, D Micol, J Agabriel (2001). Effects of
grass feeding systems on ruminant meat colour and flavour. A review. Anim
Res 50:185‒200
Schafer A, K Rosenvold, PP Purslow, HJ Andersen, P
Henckel (2002). Physiological and structural events post mortem of importance
for drip loss in pork. Meat Sci 61:355‒366
Schwaiger T, KA
Beauchemin, GB Penner (2013). The duration of
time that beef cattle are fed a high-grain diet affects the recovery from a
bout of ruminal acidosis: Dry matter intake and ruminal fermentation. J Anim
Sci 91:5729‒5742
Scollan ND, NJ Choi, E Kurt, AV Fisher, M Enser, JD Wood
(2001). Manipulating the fatty acid composition of muscle and adipose tissue in
beef cattle. Brit J Nutr 85:115–124
Semba RD, M Shardell, FA Sakr Ashour, R
Moaddel, I Trehan, KM Maleta, M Isabel Ordiz, K Kraemer, MA Khadeer, L
Ferrucci, MJ Manary (2016). Child stunting is associated with low circulating
essential amino acids. Ebiomedicine
6:246‒252
Swatland HJ (1997). Internal Fresnel reflectance from
meat microstructure in relation to pork paleness and pH. Food Res Intl
30:565‒570
Vieira C, AM Fernández (2014). Effect of ageing time on suckling lamb meat
quality resulting from different carcass chilling regimes. Meat Sci
96:682‒687
Wales WJ, JB Moran, RW Harris (1998). A comparison of
growth rates and carcass quality of steers receiving maize silage as a
supplement to annual pasture or as a component of a feedlot ration. Aust J
Exp Agric 38:1‒6
Wang CL, ZL Hao, FD Li, Y Yu, X Lang, YJ Ma, F Nian, JP
Guo (2009). Histomorphometric changes of stomach in grazing Gansu Alpine
Fine-wool Sheep at 0–56 day of age. J Gansu Agric Univ 44:10‒15
Wang
T, MJ Hou, ZH Shang, HC Wang (2018). Characteristics of muscle fibers and
relative meat quality of fattening sheep fed sweet sorghum silage and corn
silage diets. Pratac Sci 35:2722‒2727
WHO – World Health Organization (2003). Diet, nutrition and the prevention of
chronic diseases: Report of a joint WHO/FAO expert consultation, Vol. 916.
World Health Organization, Geneva, Switzerland
Wood JD, RI Richardson, GR Nute, AV
Fisher, MM Campo, E Kasapidou, PR Sheard, M Enser (2004). Effects of fatty
acids on meat quality: A review. Meat Sci
66:21‒32
Yu S, J Derr, TD Etherton, PM Kris-Etherton
(1995). Plasma cholesterol-predictive equations demonstrate that stearic acid
is neutral and monounsaturated fatty acids are hypocholesterolemic. Amer J
Clin Nutr 61:1129‒1139
Zeng YQ, YM Sun, H Wang, TS Li (1999). Studies on physicochemical properties and eating quality of
grey goat meat. J Shand Agric Univ 30:384‒389
Zhao JX, XD Liu, JX Zhang, YW Wang, HQ Li (2015).
Effect of different dietary energy on collagen accumulation in
skeletal muscle of ram lambs. J Anim Sci 93:4200‒4210
Zhao YA, YF
Yang (2003). Study on the law of muscle fiber growth of landrace rong chang pigs. Sich Anim Husb Vet 30:22‒23