Advances in Animal and Veterinary Sciences Research Article Effects of Different Fibre Sources in Pig Diets on Growth Performance, Gas Emissions and Slurry characteristics Tran Thi Bich ngoc1*, Tran Thi Thanh Thao1, Pham Van Dung2 1National Institute of Animal Science, Hanoi, Vietnam; 2Alliance of Bioversity International and International Center for Tropical Agriculture. Abstract | The effects of different fibre sources in pig diets on growth performance, ammonia (NH3), hydrogen sulphide (H2S), greenhouse gas (GHG) emissions and slurry characteristics was studied on 20 crossbred pigs [Duroc x F1 (Landrace x Yorkshire)]. The experimental diets included one low-fibre (LF) diet without maize distiller’s dried grains with solubles (DDGS), brewer’s grain (BG) and coconut cake (CC) and 3 high-fibre (HF) diets with maize DDGS or BG or CC. The experiment was conducted according to a completely randomized design with 5 replications and lasted 62 days. In the growing period and the overall, pigs fed diets LF and HF-DDGS had higher average daily gain (ADG) compared to pigs fed diets HF-BG and HF-CC (P < 0.05), wheareas the ADG was lower for pigs fed diets HF-BG and HF-CC than for diet LF (P < 0.05) in the fattening period. There was lower FCR for diets LF and HF-DDGS than for diets HF-BG and HF-CC (P < 0.05) in both periods and overall. In the growing and fattening pigs, diets didn’t affect N and P intake, slurry DM content (%) and amount of slurry (kg/head/day), slurry P content (%DM) (P > 0.05), while N and P excretions (g/head/day) were greater for diet HF-CC than for diet LF (P < 0.05). The CO2 emission was greater for diets HF-BG and HF-CC than for diets LF and HF-DDGS (P < 0.0001) in the growing period, but not for fattening period (P > 0.05). In both periods, CH4 emission was lower in diet LF than in diet HF-BG and HF-CC (P < 0.05), while NH3 emission was higher for pigs fed diet LF than pigs fed HF-BG and HF-CC (P < 0.05). The H2S emission was not affected by diets in both periods. In conclusion, different fibre sources in pig diets may be a practical method to alter growth performance, slurry characteristics and NH3, GHG emissions. Keywords | Fibre source, Emission, Growth performance, Pig diet, Slurry Received | October 12, 2020; Accepted | October 20, 2020; Published | December 10, 2020 *Correspondence | Tran Thi Bich Ngoc, National Institute of Animal Science, Hanoi, Vietnam; Email: bichngocniah75@hotmail.com Citation | Ngoc TTB, Thao TTT, Dung PV (2021). Effects of different fibre sources in pig diets on growth performance, gas emissions and slurry characteristics. Adv. Anim. Vet. Sci. 9(1): 63-72. DOI | http://dx.doi.org/10.17582/journal.aavs/2021/9.1.63.72 ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331 Copyright © 2021 Ngoc et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. INTRODUCTION cost of pork production (Iowa State University Extension, 2018), the use of by-products from food production or bi- In most countries, the intensive pig production has a sig- ofuel processing with cheap price would be recommended nificant impact on the environment. Pig manure is the as a relevant economic alternative. In this study, coconut mainly source of greenhouse gases (GHG) like methane cake (CC), distiller’s dried grains with solubles (DDGS) (CH ) and carbon dioxide (CO ), and other noxious gas- and brewer’s grain (BG) are selected in terms of different 4 2 es such as ammonia (NH ) and hydrogen sulphide (H S). soluble and insoluble non-starch polysaccharides (NSP) as 3 2 Slurry composition and gas emissions can be affected by fibrous dietary ingredient sources (Ngoc et al., 2012; Ped- diet compositions, such as sources and levels of fibre (Canh ersen et al., 2014). These differences between fibre sources et al., 1998b; Jarret et al., 2012; Kerr et al., 2020; Hansen will be expected to affect the slurry composition and GHG et al., 2007; Triolo et al., 2011; Beccaccia et al., 2015a), emissions. In a previous study, Jarret et al. (2011) evaluat- levels of protein (Canh et al., 1998a; Portejoie et al., 2004; ed the effect of the incorporation of different by-products Hernández et al., 2011) and sources of protein (Beccac- (wheat DDGS, sugar beet, and fatty rapeseed meal) on cia et al., 2015b). Feed accounts approximately 70% of the slurry composition and methane emission. They showed January 2021 | Volume 9 | Issue 1 | Page 63 NE USAcademic Publishers Advances in Animal and Veterinary Sciences that the manure issued from a diet with 20% wheat DDGS vidual pig was determined at the beginning and at the end produced less CH4 than expected, compared to the other of the experimental period before the morning feeding. diets and suggested that this could be related to the manu- Feed intake was recorded on a pen basis throughout the facturing process of wheat DDGS which requires heating experiment period to calculate average daily feed intake processes that may be causing reactions between protein (ADFI) and feed conversion ratio (FCR). and other molecules, such as lignin, resulting in products difficult to degrade by the bacteria involved in the anaer- measuremenTs anD DaTa collecTion obic digestion, in the same way as it affects the nutritional Measuring and calculating hydrogen sulfide and ammo- value. Therefore, this study was investigated to determine nia emissions: In each experimental period, after an adap- the effects of the fibrous diets containing different fibre tation period of 5 days, pens and slurry pits were cleaned. sources on NH3, H2S, GHG emissions and pig slurry char- Subsequently feces and urine were accumulated together acteristics. in the slurry pit for 26 days. At the 31st day, air samples for NH3 and H2S emission measurements were collected MATERIALS AND METHODS between 9h00 and 14h00. The study was conducted at Thuy Phuong Pig Research Air samples for determining NH3 emission were collect- Center, National Institute of Animal Science, Vietnam, ed directly from air above the slurry pits according to the from August to November 2018. method of Le et al. (2009) and with the ventilation rate of 0.5l/minute. Ammonia emission from the slurry pit was Experimental design, animals, diets and housing calculated with equation 1. The experimental diets (Table 1) were based on maize, soybean meal, fish meal, rice bran, maize DDGS, BG MNH3 = (CNH3 x V x 10.000) / (T x 60 x S) and CC. The low-fibre (LF) diets, containing around 172 [1] g NDF/kg dry matter (DM), was formulated without maize DDGS, BG and CC as feed ingredients. The HF In which: MNH3=ammonia emission (mg/s/m2), CN- diets (HF-DDGS, HF-BG and HF-CC) were formulated H3=ammonia concentration (mg/mL HNO3), V=volume around 217 - 245 g NDF/kg DM. All diets were formu- of HNO3 (mL), 10.000=cm/m2, T=sampling time (10 lated to meet NRC (1998) nutrient requirements [crude minutes), 60=s/min, S: emitting surface, 312 cm2. protein (CP), metabolizable energy (ME), calcium (Ca), phosphorus (P) and essential amino acids] (Table 2). The The principle of measuring and calculating H2S emission diets were offered in mash form. was similar to NH3. Hydrogen sulfide emission was calcu- lated with equation 1, in which the volume of HNO3 was A total of 20 crossbred pigs [Duroc x F1 (Landrace x York- replaced by that of 0.1M CdSO4. Hydrogen sulfide was shire)] from 4 litters with an equal number of males and trapped by Cadimi Sulfate 0.1M in the impinges. females, with the initial body weight (BW) of 20.7±0.44 kg (around 68 days old), distributed equally into 4 treat- ments [LF (control), HF-DDGS, HF-BG and HF-CC] according to a completely randomized design. Each treat- ment composed of 5 pens, with one pig per pen as a rep- licate. The length of the experiment was 62 days. Before the experiment started, all pigs were vaccinated. The pigs were kept individually in concrete floored pens (1.8 m x 0.8 m) with a slatted floor at the rear in an open-sided house. There was a separate manure pit (110 cm length x 50 cm width x 40 cm depth) per pen under the slatted floor. Pigs were fed 2 times per day at 08h30 and 15h30 with 4.0-5.0% of the BW. The amount of feed intake was ad- justed daily according to the expected BW gain. The pigs accessed feed and water by mixing with the ratio 1:4 (w/w) Figure 1: Schematic view of air sampling for NH3 and and they were not given any additional water in order to H2S emission measurement (1= incoming air, 2= chamber, prevent the effects of slurry volume, dilution and emitting 3=slurry pit, 4=impinger for ammonia measurement, 5= area on the emission of environmental pollution causing impinger for hydrogen sulfide measurement, 6=critical compounds and manure characteristics. The BW of indi- capillary, 7=vacuum pump) January 2021 | Volume 9 | Issue 1 | Page 64 NE USAcademic Publishers Advances in Animal and Veterinary Sciences Table 1: Feed ingredients of experimental diets (as air-dry basis) Ingredients (%) LF HF-DDGS HF-BG HF-CC Maize 63 53.2 52.04 52.2 Soybean meal 19.7 15 17.0 18.4 Fish meal 4.0 0 0 0 DDGS maize 0 25 0 0 Brewer’s grain 0 0 25 0 Coconut cake 0 0 0 25 Rice bran 10.0 0.00 0.00 0.00 Soybean oil 1.2 4 3.5 1.8 Dicalcium phosphate 0.5 1.3 0.8 0.8 Limestone meal 0.1 0.5 0.7 0.8 Premix mineral-vitamina 0.25 0.25 0.25 0.25 L-Lysine 0.05 0.25 0.21 0.23 DL-Methionine 0 0 0 0.02 Salt (NaCL) 0.5 0.5 0.5 0.5 a Content per kg of air dry diet. Vitamin A, 2000 IU; vitamin D3, 400 IU; vitamin E, 12.5 mg; vitamin K, 3 mg; vitamin B1, 2.5 mg; vitamin B12, 100 IU; Ca, 0.275 g; Cu, 27.5 mg; Fe, 25 mg; Zn, 37 mg; Co, 0.5 mg; iodine, 0.38 mg; Se, 0.11 mg. LF, low fibre diet; HF-DDGS, high fibre diet containing maize DDGS; HF-BG containing brewer’s grain; HF-CC, containing coconut cake. Table 2: Chemical compositions and nutritive values of experimental diets (as air-dry basis) Criteria LF HF-DDGS HF-BG HF-CC Dry matter (%) 89.92 90.09 90.09 90.04 Crude protein (%) 18.03 18.02 18.03 18.02 Crude fibre (%) 4.90 5.06 6.81 6.21 NDF (%) 17.21 21.73 24.47 23.67 Calcium (%) 0.62 0.61 0.60 0.59 Available phosphorus (%) 0.24 0.26 0.23 0.23 Total lysine (%) 0.97 0.93 0.95 0.96 Total Methionine+Cysteine (%) 0.58 0.58 0.57 0.54 Total threonine (%) 0.69 0.64 0.63 0.62 Total tryptophan (%) 0.23 0.19 0.22 0.23 Total NSP (%) 11.52 14.34 16.41 17.80 Soluble NSP (%) 2.73 2.98 2.55 3.33 Klason Lignin (%) 2.03 1.43 3.64 2.58 Total dietary fibre (%) 13.55 15.77 20.06 20.38 ME (Kcal/kg) 3117.85 3116.94 3121.89 3114.95 LF, low fibre diet; HF-DDGS, high fibre diet containing maize DDGS; HF-BG containing brewer’s grain; HF-CC, containing coconut cake. Collection and measurement of slurry characteristics: Measurement and calculation of greenhouse gas emis- On 28th day of each period, slurry in each slurry pit was sion: The method of static chamber has been applied ex- mixed thoroughly before a sample of about 1 kg was col- tensively to measure rates of trace gas emission sources lected. Slurry samples was kept at -200C until analysis. (Hutchinson & Mosier, 1981; Hutchinson & Livingston, Slurry samples was analysed for dry matter (DM), total 1993; Kusa et al., 2008). It allows to detect gases emitted nitrogen (N), P and pH. from a surface of a volatile solid within a known volume during a given period of time. A static chamber system was connected to a Gasmet DX-4040 Fourier Transform January 2021 | Volume 9 | Issue 1 | Page 65 NE USAcademic Publishers Advances in Animal and Veterinary Sciences Infrared Multicomponent Trace Gas Analyser (FTIR; of the Uppsala method (Theander et al., 1995), as described Gasmet Technologies Oy, Helsinki, Finland) to detect by Bach Knudsen (1997). Klason lignin was determined as GHG concentrations from pig slurry. The system includes the 12M H2SO4 insoluble residue. Total DF is the sum of a cylindrical frame, four round cylinder bases and periph- Klason lignin and total NSP (T-NSP). Content of differ- eral accessories as such sampling ports, transparent flex- ent fibre fractions were calculated as follows: ible plastic tubes. The gas analyser measures main GHG at low concentrations in parts per million unit per seconds Cellulose = NSP glucose (12 mol/l H2SO4) - NSP glucose (ppm/s) including CO2, CH4 and N2O. The response time (2 mol/l H2SO4) of the analyser is 20 seconds for one reading and the flow speed of sample pump is 1.5 liters per minute. The gas ana- Total non-cellulosic polysaccharides (T-NCP) = rham- lyzer must be calibrated with pure nitrogen (2 liters per nose + fucose + arabinose + xylose + mannose + galactose + minute speed) prior to each measurement. glucose + uronic acids Pig slurry samples were collected using white plastic plates T-NSP = T-NCP + cellulose with radius (r = 9.25 cm) and weighed the initial mass (450 Soluble NCP (S-NCP) = T-NCP - I-NCP g) using an electronic scale (Model-HY K17, 5kg) before the gas flux measurement. The GHG emissions rates were DaTa analysis determined from linear regressions, using the goodness of All data were analysed using the GLM procedures of Mi- fit and the significant level for model selection. Emission nitab Programme Version 16.2 with the kind of 4 diet as fluxes were computed from the slope of the linear regres- the main factor. When P values of the F test <0.05; Tukey sion between gas concentrations versus time within the tests were used for pairwise comparision. container headspace (Whalen and Reeburgh, 2001). As such, fluxes were calculated from the equation is described RESULTS as follow: In the growing (20-40kg), fattening (40-70kg) periods and overall, the ADFI were similar (P > 0.05) among diets (Table 3). The final BW at the growing period and the fat- Where: F is the flux rate (mass unit/m2/h1); P is the meas- tening period was statisticaly significant different among ured ambient pressure (mbar); P is the standard pressure diets (P < 0.05), with the higher value for the diets LF and 0 (1013.25 mbar); v is the total system volume (L), (); V HF-DDGS compared to the diets HF-BG and HF-CC. is the volume occupied by 1 mol of the gas at standard The diet affected the ADG and FCR in both growing and temperature and pressure (STP) (0.024 m3, or 22.4 L); A fattening periods and the overal (P < 0.05). In the growing is surface area of the chamber over the emission source period and overall, pigs fed diets LF and HF-DDGS had (0.027 m2); T is the ambient temperature in degrees celsius higher ADG compared to pigs fed diets HF-BG and HF- (0C); T CC (P < 0.05). However in the fattening period, the ADG Kelvin is the temperature T in Kelvin (K) = (273.15 + Tc); is the change in concentration in time interval t or was lower for pigs fed diets HF-BG and HF-CC than the slope of the gas concentration curve (ppm/s); M is the for diet LF (P <0.05), while diet HF-DDGS had similar molecular weight of the gas (g/mol). ADG to diets LF, HF-BG and HF-CC (P > 0.05). There was lower FCR for diets LF and HF-DDGS than for di- chemical analysis ets HF-BG and HF-CC (P < 0.05) in both growing and Dry matter (967.03), total N (984.13), ash (942.05), P and fattening periods and the overall. Ca were analysed according to the standard AOAC meth- ods (Association of Official Analytical Chemist, 1990). The The nutrient intakes are shown in Table 4. In both growing NDF content was analysed by the method of Van Soest et and fattening periods, there were no significant differences al. (1991). Amino acids were analysed by HPLC using an in N and P intake (P > 0.05), while T-NSP, S-NSP and ion exchange column (Amino Quant, 1990). Slurry pH Klason lignin intake were affected by diets (P < 0.0001). was determined by pH meter HI 8424 HANNA (Made The T-NSP intake was the highest value for diet HF- in Mauritius). CC, followed in descreasing order by diets HF-BG, HF- DDGS and LF, wheares the Klason lignin was the highest Total, soluble and insoluble NSP and their constituent for diet HF-BG, following by diets HF-CC and LF, and sugars were determined as alditol acetates by gas chroma- the lowest value for diet HF-DDGS. tography (Model: Agilent 6890N, Agilent Technologies Inc., Santa Clara, CA, USA) for neutral sugars, and by a The slurry chemical chararteristics and N, P excretion in colorimetric method for uronic acids using a modification the growing and fattening periods are presented in Table 5 January 2021 | Volume 9 | Issue 1 | Page 66 NE USAcademic Publishers Advances in Animal and Veterinary Sciences Table 3: Average daily feed intake (ADFI), average daily gain (ADG) and feed conversion ratio (FCR) for experimental diets LF HF-DDGS HF-BG HF-CC SEM P Growing period (20-40 kg) Initial BW (kg) 20.78 20.74 20.64 20.68 0.441 0.996 Final BW (kg) 41.20a 40.90a 38.50ab 38.10b 0.682 0.009 ADG (g) 659a 650a 576b 562b 20.27 0.006 ADFI (kg) 1.48 1.50 1.49 1.45 0.045 0.815 FCR (kg feed/kg gain) 2.26a 2.31a 2.59b 2.57b 0.065 0.003 Fattening period (40-70 kg) Initial BW (kg) 41.20a 40.90a 38.50ab 38.10b 0.682 0.009 Final BW (kg) 70.90a 70.40a 65.80b 64.90b 1.119 0.002 ADG (g) 958a 952ab 881b 864b 22.92 0.020 ADFI (kg) 2.60 2.63 2.60 2.55 0.058 0.797 FCR (kg feed/kg gain) 2.72a 2.77a 2.97b 2.95b 0.067 0.037 Overall (20-70 kg) ADG (g) 808a 801a 728b 713b 16.33 0.001 ADFI (kg) 2.04 2.07 2.05 2.00 0.045 0.739 FCR (kg feed/kg gain) 2.53a 2.58a 2.82b 2.80b 0.045 0.001 LF, low fibre diet; HF-DDGS, high fibre diet containing maize DDGS; HF-BG containing brewer’s grain; HF-CC, containing coconut cake; BW, body weight. Table 4: Average daily nutrient intake (g) for experimental diets LF HF-DDGS HF-BG HF-CC SEM P Growing period (20-40 kg) Nitrogen 42.81 43.36 43.10 41.69 1.304 0.812 Phosphorus 7.57 7.67 7.77 7.52 0.233 0.876 Total NSP 170.96a 215.67b 245.17c 257.39c 6.633 <0.0001 Soluble NSP 41.11bc 45.12ab 38.1c 48.15a 1.281 <0.0001 Klason Lignin 30.13a 21.51b 54.38c 37.31d 1.212 <0.0001 Fattening period (40-70 kg) Nitrogen 75.00 75.94 75.12 73.58 1.680 0.796 Phosphorus 13.26 13.43 13.54 13.27 0.299 0.891 Total NSP 299.52a 377.72b 427.32c 454.26c 8.227 <0.0001 Soluble NSP 72.02a 79.02b 66.4a 84.98b 1.644 <0.0001 Klason Lignin 52.78a 37.67b 94.79c 65.84d 1.465 <0.0001 Table 5: Slurry chemical characteristics and nitrogen (N) and phosphorus (P) excretion by experimental diets LF HF-DDGS HF-BG HF-CC SEM P Growing period (20-40 kg) pH slurry 7.46a 7.34ab 7.26b 7.20b 0.047 0.007 Slurry DM (%) 17.29 15.46 17.07 17.79 0.592 0.067 Slurry amount (kg DM/head/day) 0.19 0.18 0.19 0.20 0.009 0.453 Slurry N (%DM) 2.92a 3.23ab 3.68ab 4.16b 0.267 0.025 Slurry P (%DM) 1.39 1.57 1.72 1.80 0.115 0.096 Excreta N (g/head/day) 5.42a 5.83a 6.81ab 8.28b 0.465 0.002 Excreta P (g/head/day) 2.55a 2.82ab 3.23ab 3.59b 0.200 0.011 Fattening period (40-70 kg) January 2021 | Volume 9 | Issue 1 | Page 67 NE USAcademic Publishers Advances in Animal and Veterinary Sciences pH slurry 6.66a 6.62a 6.41ab 6.30b 0.066 0.004 Slurry DM (%) 17.87 17.57 17.97 19.07 0.608 0.352 Slurry amount (kg DM/head/day) 0.27 0.26 0.28 0.30 0.017 0.394 Slurry N (%DM) 3.42 3.74 4.14 4.12 0.240 0.145 Slurry P (%DM) 1.32a 1.51ab 1.63ab 1.80b 0.093 0.018 Excreta N (g/head/day) 9.02a 9.74ab 11.47bc 12.17c 0.576 0.004 Excreta P (g/head/day) 3.48a 3.94a 4.55ab 5.38b 0.329 0.005 Slurry: faeces+urine In the growing period, slurry DM content (%) and amount either DDGS or BG or CC had similar ADFI in both (kg/head/day), slurry P content (%DM) did not differ growing and fattening periods and the overall. These re- among diets (P > 0.05) (Table 5). The highest pH slurry sults are similar to earlier studies (Len et al., 2009; Ngoc was observed for diet LF (7.46), followed in descending and Dang, 2016) that didn’t observe differences in DM order by diet HF-DDGS (7.34), diet HF-BG (7.26) and intake of pigs given LF and HF diets on the basis of rice diet HF-CC (7.20) (P < 0.05). Slurry N content (%DM) bran, sweet potato vines, cassava residue (CR), tofu residue and N and P excretions (g/head/day) were similar among and CC. In contrast, Ngoc et al. (2013) showed that fibre diets LF, HF-DDGS and HF-BG (P > 0.05), while they source had an impact on mean retention time, with the were greater in diet HF-CC than in diet LF (P < 0.05). shorter mean retention time of CR as compared with BG, resulting in lower DM intake for HF diet containing CR Similar to the growing period, in the fattening period there than HF diet containing BG. were no differences in slurry DM content (%) and amount (kg/head/day), slurry N content (%DM) among diets (P > In the growing period, pigs fed the LF and HF-DDGS di- 0.05) (Table 5). The pH slurry was affected by diets (P < ets improved ADG compared to pigs fed the HF-BG and 0.05), with the higher value for diets LF and HF-DDGS, HF-CC diet. This could be due to an association of lower followed by diet HF-BG and the lowest value for HF-CC. T-NSP and Klason lignin intake (Table 3), thus resulting However, pigs fed diet LF showed lowest slurry P content in better dietary nutrient digestibility in the LF and HF- (%DM) and N and P excretions (g/head/day), followed DDGS diets. In previous studies (Högberg and Lindberg, in decreasing order by diet HF-DDGS, diet HF-BG and 2004; 2006; Serena et al., 2008; Ngoc et al., 2013), source HF-CC (P < 0.05). and level of dietary fibre had a pronounced effect on the site of organic mater, CP and GE digestion. The digest- In the growing period, the concentration of CO2 emission ibility of OM, CP and GE at ileum and total tract was was greater for diets HF-BG and HF-CC than for diets reduced with an increase in dietary fibre level. Besides, the LF and HF-DDGS (P < 0.0001) (Table 6). However, in total tract digestibility of OM, CP and GE was improved the fattening pigs, the CO2 emission in diets HF-DDGS with an increase in the solubility of the dietary fibre frac- and HF-BG didn’t differ to diets LF and HF-CC (P > tion in the diets containing different fibre sources. In the 0.05), but it was different significance between diets LF fattening period, diet LF had higher ADG compared to and HF-CC (P < 0.005). In both growing and fattening diets HF-BG and HF-CC, but it was not different among periods, the CH4 emission in diet HF-BG was similar to diets HF-DDGS, HF-BG and HF-CC. These results in- diets HF-DDGS and HF-CC (P > 0.05), whereas it was dicated that apparently the animal response to diets con- lower in diet LF than in diets HF-BG and HF-CC (P < taining different fibrous feed sources may relate to the age 0.05). In the growing period, the NH3 emission was high- of animals, the older pigs can utilize fibrous diet better er for pigs fed diet LF than pigs fed HF-BG and HF-CC than younger pigs (Choct et al., 2010). (P < 0.05), while it was similar among diets HF-DDGS, HF-BG and HF-CC (P > 0.05). In the fattening period, Diet composition had effects on nutrient digestibility and the NH3 emission was lower for pigs fed diets HF-BG metabolism, and on the fermentation rates in the hindgut, and HF-CC than for pigs fed diets LF and HF-DDGS as resulted in affecting slurry characteristics and thus gas (P < 0.05). The concentration of N2O and H S emissions emissions (Møller et al., 2004a,b; Dinuccio et al., 2008). 2 did not differ among diets (P > 0.05) in both growing and Pigs showed lower N excretion for the LF diet than for the fattening periods. HF-CC diet in the growing and fattening periods and this result may be due to T-NSP intake was lower in the LF DISCUSSION diet than in the HF-CC diet (Table 4). Inclusion of NSP into pig diets also shifts N excretion from urine to feces In the current study, pigs fed diets LF and HF containing (Canh et al., 1997; Galassi et al., 2010; Heimendahl et al., 2010). Because of fecal N is less easily degraded to NH3, January 2021 | Volume 9 | Issue 1 | Page 68 NE USAcademic Publishers Advances in Animal and Veterinary Sciences Table 6: Gas emissions from slurry by experimental diets LF HF-DDGS HF-BG HF-CC SEM P Growing period (20-40 kg) CO (g/h/m2) 2.62a 3.49a2 5.87b 6.22b 0.277 <0.0001 CH4 (mg/h/m2) 375.56a 490.72ab 575.30bc 692.55c 34.801 <0.0001 N2O (µg/h/m2) 2.10 1.92 1.64 1.53 0.362 0.247 NH3 (mg/h/m2) 0.479a 0.439ab 0.369b 0.356b 0.0215 0.002 H2S (mg/h/m2) 0.054 0.064 0.071 0.063 0.0102 0.715 Fattening period (40-70 kg) CO2 (g/h/m2) 2.56a 3.023ab 3.157ab 3.797b 0.225 0.003 CH4 (mg/h/m2) 364.40a 413.19ab 476.45bc 498.45c 19.58 <0.0001 N2O (µg/h/m2) 2.64 2.13 1.99 1.72 0.561 0.710 NH (mg/h/m2) 0.551a 0.541a3 0.444b 0.420b 0.0170 <0.0001 H2S (mg/h/m2) 0.079 0.085 0.095 0.087 0.0075 0.550 the inclusion of sugar beet pulp into grow-finishing diets of fibre studied was parallel to an increase of dietary fibre results in a linear relationship between the NSP intake and concentration, and therefore the effects of source and level the NH3 emission, decreasing by 5.4% for each 100g inc- of the ingredients used were confounded. rease in the intake of dietary NSP (Canh et al., 1998b). Various nutritional strategies, as the inclusion of fibre Most of CH4 emissions in pigs are originated from the sources in feeds, have been proposed in order to mitigate digestive tract and during manure storage, as a result of NH3 emission derived from manure in pig farms. Sever- the degradation of organic compounds by methanogenic al works indicate that these effects are depending on the archaea. They will depend both on the amount and com- type of fibre used. Dietary supply of fermentable fibre also position of organic matter excreted. Highly lignified cell reduced faecal and slurry pH through an increase of vol- wall components of feeds remain undigested and consti- atile fatty acids (VFA) formation in the large intestine, tute the main energy substrate for CH4 production, and thereby decreasing additionally NH emission (Canh et can also increase the excretion of other nutrients in faeces. 3 al., 1998a,b). These results were confirmed by the current However, cellulose and lignin have the lowest CH4 poten- study with higher slurry pH and NH emission for diets tial emissions, whereas undigested lipids and protein have 3 LF and HF-DDGS than for diet HF-BG and HF-CC. the highest (Angelidaki and Sanders, 2004). In practical Increasing dietary fibre in pig diets is generally to decrease conditions, the inclusion of different fibre sources, such as manure pH and NH -N concentrations (Kerr et al., 2006, DDGS, sugar beet pulp or rapeseed meal led to variable 4 2018; Ngoc and Dang, 2016; Trabue and Kerr, 2014; van effects on the potential for CH4 production from faeces Weelden et al., 2016), but this is not always a consistent and the total CH4 produced per pig ( Jarret et al., 2011, observation (van Weelden et al., 2016). The study by Kerr 2012). Thus, altering source of dietary fibre can potentially et al. (2020) was no exception to this lack of consisten- serve to manipulate CH4 emissions from slurry. The cur- cy and the authors reported that manure from pigs fed rent data showed that CH4 production from slurry was the HF-DDGS diet had higher manure NH4-N, but no higher 1.15-1.53 and 1.21-1.84 times in diets HF-BG change in manure pH, compared to pigs fed the LF con- and HF-CC compared to diets HF-DDGS and LF in taining corn-soybean meal diet; while pigs fed the HF both growing and fattening pigs, respectively. This result containing soybean hull diet produced a manure with sim- could be due to diets HF-BG and HF-CC had higher ilar NH -N, but lower pH, compared to manure from pigs intake of total DF and other fibre components (NDF, 4 fed the corn-soybean meal diet. Besides, it is suggested T-NSP and Klason lignin) than diets HF-DDGS and LF, that the use of more lignified fibre sources (e.g. oat hulls) leading to more methanogens diversity (Cao et al., 2012) had no influence on N partitioning (Zervas and Zijlstra, or abundance (Liu et al., 2012), and therefore increasing 2002; Bindelle et al., 2009); otherwise, it decreases nutri- CH4 emission (Seradj et al., 2018). In the experiment done ent digestibility and might then modify excreta composi- by Ngoc and Dang (2016), CH4 emitted from slurry high- tion and NH emission. Beccaccia et al. (2015a) indicated er for HF diet than for LF diet by from 13% to 18%. Pigs 3 that CP digestibility was decreased when NDF in the diet fed diet HF-CC increased CH4 emission from slurry by was replaced with more fermentable or lignified sources of from 10% to 12% compared with pigs fed diet tofu residue. fibre led to an increase of faecal CP excretion on DM and The current data showed that CO2 production from slurry N concentration in urine DM and a decrease of g NH / was higher 1.68-2.24 and 1.78-2.37 times in diets HF-3 kg slurry. In all these works, inclusion of the various types BG and HF-CC compared to diets HF-DDGS and LF January 2021 | Volume 9 | Issue 1 | Page 69 NE USAcademic Publishers Advances in Animal and Veterinary Sciences in the growing pigs, respectively. However, the emission of of plant materials used in animal feeding. Anim. Feed Sci. CO2 from feaces was observed greater 1.48 times for diet Technol. 67: 319 - 338. https://doi.org/10.1016/S0377- HF-CC compared to diet LF in fattening pigs. According 8401(97)00009-6 to Ngoc and Dang (2016), fibre source and fibre level had • Beccaccia A, Calvet S, Cerisuelo A, Ferrer P, García-Rebollar P, De Blas C (2015a). Effects of nutrition on digestion no impact on the emission of CO2 from slurry in both efficiency and gaseous emissions from slurry in growing- growing and fattening pigs, except for the impact of fibre finishing pigs. I. Influence of the inclusion of two levels of level on CO2 emission in the growing pigs. Philippe et orange pulp and carob meal in isofibrous diets. Anim. Feed al. (2015) reported the emissions of CO2 did not shown Sci. Technol. 208: 158 - 169. https://doi.org/10.1016/j. any significant difference regarding the diets LF and HF, anifeedsci.2015.07.008 as well for gestating sows as for fattening pigs. However, • Beccaccia A, Cerisuelo A, Calvet S, Ferrer P, Estellés F, De Blas C, García-Rebollar P (2015b). Effects of nutrition Clark et al. (2005) indicated that pigs fed diet with 20% on digestion efficiency and gaseous emissions from slurry sugar beet pulp reduced CO2 emission from slurry sam- in growing pigs: II. Effect of protein source in practical ples by 17% compared to 0% sugar beet pulp. diets. Anim. Feed Sci. Technol. 209: 137 - 144. https://doi. org/10.1016/j.anifeedsci.2015.07.021 CONCLUSIONS • Bindelle J, Buldgen A, Delacollette M, Wavreille J, Agneessens R, Destain JP, Leterme P (2009). Influence of source and concentrations of dietary fibre on in vivo nitrogen excretion Different fibre sources in pig diets is a potential method to pathways in pigs as reflected by in vitro fermentation and alter growth performance, slurry characteristics and NH3, nitrogen incorporation by fecal bacteria. J. Anim. Sci. 87: GHG emissions. Diets LF and HF-DDGS had higher 583 - 593. https://doi.org/10.2527/jas.2007-0717 ADG and NH3 emission, and lower N, P excretion and • Canh TT, Aarnink AJA, Schutte JB, Sutton A, Langhout DJ, CO2, CH4 emissions than diets HF-BG and HF-CC. Verstegen MWA (1998a). Dietary protein affects nitrogen excretion and ammoniaemission from slurry of growing finishing pigs. Livest. Prod. Sci. 56: 181-191. https://doi. ACKNOWLEDGEMENTS org/10.1016/S0301-6226(98)00156-0 • Canh TT, Sutton AL, Aarnink AJA, Verstegen MWA, Schrama This study was financed by SIDA/SAREC (Swedish In- JW, Bakker GCM (1998b). Dietary carbohydrates alter the ternational Development Cooperation Agency - Depart- fecal composition and pH and the ammonia emission from ment for Research Cooperation), through the regional slurry of growing pigs. J. Anim. Sci. 76: 1887 - 1895. https://doi.org/10.2527/1998.7671887x MEKARN II program and the Swedish University of • Canh TT, Verstegen MWA, Aarnink AJA, Schrama JW (1997). Agricultural Sciences. Influence of dietary factors on nitrogen partitioning and composition of urine and feces of fattening pigs. J. Anim. CONFLICT OF INTEREST Sci. 75: 700 - 706. https://doi.org/10.2527/1997.753700x• Cao Z, Liao XD, Liang JB, Wu YB, Yu B (2012). Diversity of methanogens community in hindgut of grower and finisher The authors declare that they have no conflict of interest. pigs. Afri. J. Biotech. 2: 4949 - 4955. • Choct M, Dersjant-Li Y, McLeish J, Peisker M (2010). Soy AUTHORS CONTRIBUTION oligosaccharides and soluble non-starch polysaccharides: a review of digestion, nutritive and anti-nutritive effects in TTBN, the first author, designed the study, coordinated pigs and poultry. Asian-Aust J. Anim. Sci. 23(10): 1386 - 1398. https://doi.org/10.5713/ajas.2010.90222 the work, analysed the data and wrote the manuscript. • Clark OG, Moehn S, Edeogu I, Price J, Leonard J (2005). 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