CN104605162A - Application of aspergillus oryzae as beef cattle intestinal tract and excrement methane inhibitor - Google Patents

Abstract

The invention discloses application of aspergillus oryzae as a beef cattle intestinal tract and excrement methane inhibitor. Aspergillus oryzae is added into a totally-mixed beef cattle fodder and the fodder is fed to beef cattle at the dosage of 8-12 mg/kg each day. The application of aspergillus oryzae as the beef cattle intestinal tract and excrement methane inhibitor has both environmental and economical benefits.

Description

Application of Aspergillus oryzae as Intestinal and Fecal Methane Inhibitor in Beef Cattle

technical field

The invention relates to the technical field of greenhouse gas emission reduction, in particular to the application of Aspergillus oryzae as an inhibitor of beef cattle intestinal tract and feces methane.

Background technique

Methane is an important greenhouse gas, and its greenhouse effect is 20-30 times that of carbon dioxide. The effect of methane on global warming accounts for 15%-20% of all factors affecting climate warming. And a large part of it comes from ruminants. Methane is a product of the digestion process of ruminants. Its chemical properties are stable, and it is generally difficult to digest and absorb in the body. It is mainly excreted in the form of belching. In addition, the amount of methane produced by ruminant feces cannot be ignored. The emission of methane means the loss of energy. Studies have shown that the energy lost by ruminants in the form of methane accounts for 2% to 15% of the total energy intake. Therefore, the research on methane inhibitors for ruminants has both environmental and economic advantages. benefit.

With the improvement of people's living standards, the demand for beef is constantly increasing. Therefore, the number of beef cattle breeding continues to increase, and the resulting environmental problems have gradually attracted people's attention. At present, the common methane inhibitors are mainly divided into polyhalogen compounds, ionophore compounds, organic acids, microbial agents, plant extracts, saponins and oils and other substances. All kinds of methane inhibitors are in the initial stage of research. Some methane inhibitors have unstable effects or damage the rumen environment, resulting in disadvantages such as reduced feed utilization. Therefore, it is necessary to develop effective ruminant methane inhibitors. Aspergillus oryzae is a food-grade strain recognized as safe by FAO/WHO. It is a microbial product that can be directly fed to animals. Previous studies have shown that Aspergillus oryzae can improve the digestibility of fiber in dairy cow diets, but there are also inconsistent results. There are also reports about Aspergillus oryzae as a feed additive in the prior art, wherein Aspergillus oryzae mainly improves the production performance and body condition of ruminants by improving the fermentation performance of rumen of ruminants. However, there is no report about whether Aspergillus oryzae can reduce the emission of methane in the intestinal tract and manure of beef cattle and the optimal addition effect.

Contents of the invention

The purpose of the present invention is to reduce beef cattle manure and intestinal methane emission by supplementing a certain amount of methane inhibitor to beef cattle.

The purpose of the present invention can be achieved through the following technical solutions.

Use of Aspergillus oryzae as an inhibitor of intestinal and fecal methane in beef cattle.

Method of use: Add Aspergillus oryzae to the whole mixed feed of beef cattle, and the daily unit weight feeding dosage is 8-12mg/kg body weight.

Beneficial effects of the present invention: the daily average methane output of the intestinal tract, the methane production per unit weight and the methane energy of the test beef cattle are respectively reduced by 18.77%, 20% and 18.73%. In addition, the average daily methane emission flux of the experimental beef cattle manure during natural stacking and storage (0-45 days) was reduced by 55.55%. The application of Aspergillus oryzae as an inhibitor of intestinal and fecal methane in beef cattle has both environmental and economic benefits.

Description of drawings

Figure 1 is a plot of fecal methane emission rate versus time.

Detailed ways

Effects of Aspergillus oryzae on intestinal and fecal methane emission and production performance of beef cattle

1 Materials and methods

1.1 Selection and feeding management of experimental animals

The experiment was carried out at the Maozhuang practice base of Henan Agricultural University. Select 8 healthy and disease-free Simmental crossbred beef cattle with similar body weight, monthly age, and daily gain, and randomly divide them into two groups (control, Aspergillus oryzae). At 18:00, the same full mixed ration was fed.

1.2 Experimental design

The feeding experiment was carried out from April to May 2014, with a total of 37 days (7-day pre-trial period, 30-day main trial period). The control group was fed with basal diet; the Aspergillus oryzae group was fed with 8-12 mg/kg body weight of Aspergillus oryzae additive in the basal diet; in the last 5 days of the test, the intestinal methane emission of test cattle was measured by SF ₆ tracer method.

The fecal methane emission test was conducted from May to July 2014 for a total of 45 days. At the later stage of the feeding experiment, the feces excreted by the test cows in the control group and the Aspergillus oryzae group were collected, and they were respectively piled up in manure piles with a length × width × height of 2.00 × 1.00 × 0.10m, stored in the open air, and measured by static box-gas chromatography. The methane emission fluxes excreted by beef cattle in the three groups were measured at three points for each test group. The methane emission flux of the two groups of feces was collected from 8:30 to 9:00 every day for 9 days before stacking, and then measured every other day.

1.3 Test materials

The methane inhibitor is Aspergillus oryzae.

1.4 Test indicators and methods

1.4.1 Production performance

Average daily gain: measure the weight of each cow with a weighbridge at the beginning of the pre-test period and at the end of the test, and calculate the average daily gain according to the following formula.

Calculation formula:

Feed intake: Measure the feed intake of the cattle every 5 days, and at the same time collect samples of the total mixed ration, measure the dry matter content (70°C), and calculate the average daily dry matter intake of each cow.

1.4.2 Enteric methane emissions

1.4.2.1 At the beginning of the gas collection test, the SF ₆ permeation tube with known permeation rate was put into the rumen, and the gas exhaled by the test cow was collected every day in the last 5 days of the official period, with 24 hours as a cycle. The collected samples were sent back to the test on the same day to measure the concentration of SF ₆ and CH ₄ , and the intestinal methane emission of the test cattle was calculated according to the following formula:

(1)

In the formula:

R _CH4 －Ruminant methane emission rate, L/d;

R _SF6 - permeation rate of SF ₆ , mg/d;

6.518 - the density of SF ₆ , kg/m ³ ;

[ CH ₄ ] - the concentration of CH ₄ in the sample gas, 10 ^-6 (mol fraction);

[ SF ₆ ] - the concentration of SF ₆ in the sample gas, 10 ^-12 (mole fraction).

1.4.2.2 Gas concentration measurement

Determination of SF6 concentration:

A gas chromatograph equipped with an electron capture detector (ECD) was used on a 5Å molecular sieve column. The column temperature was 50°C, the inlet temperature was 100°C, and the detector temperature was 250°C. Injection volume: 1mL.

CH4 Concentration Determination:

A gas chromatograph equipped with a hydrogen flame ionization detector (FID) was used, and the PQ packed column. The column temperature was 55°C, the inlet temperature was 150°C, and the detector temperature was 200°C. Injection volume: 1 mL.

1.4.3 Fecal methane emission flux

1.4.3.1 Gas sampling When sampling, fasten the lid of the box and seal it with water. At 0, 10, 20, and 30 minutes after buckling the lid, take air from the airway with a 50mL syringe, inject the collected air into a 0.1L all-plastic switching valve aluminum foil composite film air collection bag, and bring it back to the experiment The chamber analyzes the gas samples for the concentration of methane using a gas chromatograph. After sampling, open the box cover and maintain natural ventilation.

Calculate the discharge flux of manure with the following formula:

In the formula: R is the greenhouse gas emission flux (mg.m ^-2 .min ^-1 ); M is the gas molar mass (g.mol ^-1 ); V ₀ is the gas molar volume under standard conditions (0°C, 1013hPa) , (22.41×10 ^-3 m ³ .mol ^-1 ); T ₀ and P ₀ are the absolute temperature (K) and air pressure (hPa) of the air in the standard state, respectively; T and P ₀ are the actual temperature (K) and actual air pressure (hPa); dC _t /d _t is the slope of the regression line of the greenhouse gas concentration in the box during the observation period, and C _t is the volume mixing ratio concentration of the measured gas in the box at time t (v /v); t is the time (min); h is the height of the sampling box (m).

1.4.3.2 Gas sample analysis The methane content was determined by gas chromatography. Detector temperature (F1D) 200°C; inlet temperature 120°C; column temperature 65°C; standard sample concentration 20.1ppm.

1.4.3.3 Determination of environmental indicators

While collecting gas, a barometer was used to measure the actual air pressure of the test site, which was used to calculate the emission flux of fecal methane. And use the automatic temperature and humidity measuring instrument to record the ambient temperature during the test every 5 minutes.

1.5 Data processing

Data statistics using spss17.0 to conduct one-way analysis of variance for each group of data, the results are expressed as mean ± standard deviation (Mean+SD).

2 Results and Analysis

2.1 Daily gain and feed intake of experimental cattle

Table 1 Daily gain of test cattle

Note: Different uppercase letters in the same column indicate extremely significant differences ( p <0.01), different lowercase letters indicate significant differences ( p <0.05), and same letters and no note indicate no significant differences ( p >0.05).

It can be seen from Table 1 that the differences in initial body weight, final weight, average daily gain and dry matter intake between the control group and the Aspergillus oryzae group were not significant (p>0.05), but the average daily gain and The dry matter intake was 11.11% and 0.94% higher than that of the control group, respectively. It shows that Aspergillus oryzae has a tendency to increase the average daily gain and dry matter intake of beef cattle.

2.2 Intestinal methane emission of test cattle

The average daily methane emissions of the test cattle are shown in Table 2. It can be seen that the differences between the control group and the Aspergillus oryzae group in the daily average methane production, methane production per unit weight, and methane energy in the intestinal tract of the test cattle reached a very significant level (p<0.01), and the intestinal tract of the test cattle in the Aspergillus oryzae group The average daily methane production, methane production per unit weight and methane energy were 18.77%, 20% and 18.73% lower than those of the control group, respectively. It can be seen that Aspergillus oryzae has a significant effect as a beef cattle intestinal methane inhibitor.

Table 2 Methane emission of test cattle index control group Aspergillus oryzae group Methane production L·(head·d) ^-1 418.90±23.79 ^Aa 340.24±16.75 ^Bb Methane production per unit weight L·kg ^-1 0.70±0.02 ^Aa 0.56±0.01 ^Bb Methane Energy MJ·d ^-1 16.76±0.95 ^Aa 13.62±0.67 ^Bb

Note: Different uppercase letters in the same column indicate extremely significant differences ( p <0.01), different lowercase letters indicate significant differences ( p <0.05), and same letters and no note indicate no significant differences ( p >0.05).

2.3 Fecal methane emission flux

Figure 1 shows the plot of fecal methane emission rate as a function of time during the test period. During the test period, the daily average temperature of the external environment was 27.63°C and fluctuated. The average daily fecal methane emission fluxes of the control group and the Aspergillus oryzae group were 2683.33 and 1165.86 mg·m ^-2 ·d ^-1 , respectively . The average daily fecal methane emission flux of the Aspergillus oryzae group was 55.55% lower than that of the control group, and the range of change between the two groups was inconsistent with the prolongation of the stacking time. In the first 15 days of stacking, the change trends of the two were basically the same, but after 15 days, the peak of methane emission appeared in the control group, and then the methane emission flux gradually decreased.

3 Summary

Adding an appropriate amount of Aspergillus oryzae (8-12mg/kg body weight) to the diet of beef cattle has no significant effect on the daily gain and dry matter intake of beef cattle, but there is a tendency to increase; Aspergillus oryzae can significantly reduce the intestinal and Methane emissions from manure.

Claims (2)

1. The application of Aspergillus oryzae as a beef cattle intestinal and fecal methane inhibitor. 2. the application of aspergillus oryzae according to claim 1 as beef cattle intestinal tract and feces methane inhibitor, is characterized in that: aspergillus oryzae is added in the whole mixed feed of beef cattle, and daily feeding dosage is 8-12mg/kg body weight .