Effects of inclusion level and adaptation period on nutrient digestibility and digestible energy of wheat bran in growing-finishing pigs

Objective This experiment was to evaluate the effect of different inclusion levels and adaptation periods on digestible energy (DE) and the apparent total tract digestibility (ATTD) of chemical constituents in diets supplemented with wheat bran. Methods Thirty-six crossbred barrows with an initial body weight of 85.0±2.1 kg were allotted to 6 diets in a completely randomized block design with 6 pigs per diet. Diets included a corn-soybean basal diet and 5 additional diets which were formulated by replacing corn and soybean meal in control diet with 15%, 25%, 35%, 45%, or 55% wheat bran. The experiment lasted for 34 d, and feces were collected from d 8 to 13, 15 to 20, 22 to 27, and 29 to 34 respectively. Results The results showed no interaction effects between inclusion level and adaptation period on the concentration of DE and the ATTD of gross energy (GE) and crude protein (CP) in wheat bran. The DE value and ATTD of GE in wheat bran decreased (p<0.05) significantly as the inclusion level of wheat bran increased, but no difference in the ATTD of CP was observed. The ATTD of CP in wheat bran increased (p<0.10) significantly as the adaptation period for pigs was prolonged. In addition, the concentration of DE and the ATTD of GE in wheat bran decreased linearly (p<0.05) when pigs were fed either an increased level of wheat bran or given an increased adaptation period to the diets. Conclusion Wheat bran showed a negative effect on the concentration of DE and ATTD of GE and CP as the inclusion level increased. A longer adaptation period can gradually increase the DE value and ATTD of GE and CP in wheat bran, and at least 14 to 21 d of adaptation might be recommended for growing-finishing pigs fed the high-fiber diets with wheat bran

Experimental Study of CO₂-ECBM by Injection Liquid CO₂

Coal mine gas disasters have severely restricted production safety. Improving gas extraction efficiency can effectively reduce disasters. Scholars have confirmed that CO2 successfully displaces coal seam CH4. This study conducted displacement and in situ experiments and compared gas drainage under different injection pressures. The displacement experiments indicated that CH4 production rates increased under increased pressures while the displacement ratios decreased. The pressure had a positive effect on sweep efficiency. The in situ experiment showed that CH4 and CO2 concentration trends in the inspection hole remained consistent. Through observing the data of the original and inspection holes, the average gas drainage concentration during low- and medium-pressure injections increased by 0.61 times and 1.17 times, respectively. The low-pressure average gas drainage scalar was increased by 1.08 times. During the medium-pressure injection, the average gas drainage purity increased by 1.94 times. The diffusion ranges of CO2 under low- and medium-pressure injections were 20–25 m and 25–30 m, respectively. The sweep efficiency of medium-pressure injection was 26% better than that of the low-pressure injection, with average pressures of 2.8 MPa and 1.4 MPa, respectively, for sweep efficiency. This study proposes an effective method for improving coal mine gas drainage efficiency

Comparative energy digestibility of protein feed ingredients in crossbred barrows in different growing stages

This study was conducted to determine the effect of different growing stages on digestible energy (DE) and metabolizable energy (ME) in soybean meal (SBM), cottonseed meal (CSM), rapeseed meal (RSM), corn gluten meal (CGM), and corn distillers dried grains with solubles (DDGS) fed to crossbred barrows. Thirty-six growing barrows (GS 1: 29.1 ± 2.85 kg BW), 36 growing barrows (GS 2: 59.2 ± 4.91 kg BW), and 36 finishing barrows (GS 2: 105.4 ± 6.91 kg BW) were allotted to 6 diets in a completely randomized design with 6 replicated pigs per diet per growth stage or BW. Faecal and urine samples were collected for 5 days after a 12-day adaption period. The results showed that the concentration of DE in corn for pigs at GS 3 was greater (P < .05) than that for pigs at GS 1. The concentration of DE and ME in CSM were lower (P < .05) fed to pigs at GS 1 and 2 compared with those at GS 3. Similar effects of BW were observed with corn DDGS. In conclusion, different DE values for corn, and DE and ME values for CSM and corn DDGS, should be used when formulating diets for growing and finishing barrows

开放科学中文社区(Chinese Open Science Network)

This is a Public Project to sharing resources for Reproducibility and Open Science in Chinese, see Wiki for more details