Composition Of Excreta Research Articles

Effects of Feeding Low Protein Diets with Different Energy-to-Protein Ratios on Performance, Carcass Characteristics, and Nitrogen Excretion of Broilers.

This study shows the effects of feeding low protein (LP) diets with different energy-to-protein ratios were evaluated on the production parameters, carcass composition, meat quality, nitrogen retention, and excreta composition of broilers. A total of 576-day-old Ross 308 broilers were fed a control diet (C) and three LP diets containing 1.5% less crude protein than diet C for 41 days. The LP1 treatment was isocaloric with diet C, while the dietary apparent metabolizable energy corrected by nitrogen (AMEn) levels in the case of the LP2 and LP3 treatments were reduced by 1.5% and 3%, respectively. The LP diets were supplemented with six crystalline essential amino acids (AA) to meet the standardized ileal digestible AA requirements of broilers. The LP1 treatment did not affect the performance parameters of broilers and increased the breast meat yield, the nitrogen retention and decreased drip loss of breast meat and the total-N and uric acid-N nitrogen excretion of birds in comparison with the C group. Although the energy-reduced LP2 and LP3 diets resulted in lower final body weight, they did not affect the carcass composition, breast meat quality, nitrogen retention, and excreta composition of birds compared with the control treatment.

Efficacy of the probiotic Bacillus licheniformis DSM 28710 in laying hens fed barley-sunflower meal-based diets on performance egg quality and excreta composition

Efficacy of the probiotic Bacillus licheniformis DSM 28710 in laying hens fed barley-sunflower meal-based diets on performance egg quality and excreta composition

Effect of β-glucan, carotenoids, oligosaccharides and anthocyanins on bacteria groups of excreta in broiler chickens

This study was conducted to examine the effect of natural compounds, such as β-glucan, carotenoids, oligosaccharides, and anthocyanins in the diet on bacteria gropus of excreta in Ross 308 broiler chickens. Chickens were fed 5 diets: control (basal) diet, a diet supplemented by β-glucan at 0.05%, and diets supplemented by carotenoids, oligosaccharides, or anthocyanins at 0.5% of each compound. On experimental day 19, excreta were collected to determine the proportion of Lactobacillus, Bifidobacterium, Campylobacter, Clostridium, and Escherichia coli. Samples were collected aseptically and snap-frozen in liquid nitrogen. Bacterial DNA was isolated from samples, then polymerase chain reaction using primer pairs designed to the 16S rDNA of bacterial groups were applied to define the proportion of the mentioned bacteria. Another universal primer pair was used to amplify a region of 16S rDNA of all the examined bacteria. Proportion of each bacterial groups was determined relatively to the intensity of universal PCR product band by gel documenting system and ImageLab software. Based on the results, carotenoids and anthocyanins increased the proportion of Bifidobacterium, which might imply the beneficial effects of the mentioned compounds on the bacteria composition of excreta.

Reduction of dietary crude protein and feed form: Impact on broiler litter quality, ammonia concentrations, excreta composition, performance, welfare, and meat quality.

Nitrogen (N) excreted by poultry is converted to ammonia (NH3), presenting an environmental risk and a health risk to the farmer and animals. A study was performed to investigate the effect of reduced CP and feed form on broiler performance and welfare, meat and litter quality, N utilization, and NH3 concentrations at litter level. A total of 2,232 Ross 308 male broilers was divided into 6 treatments and 6 replicates, which was fed diets in both pellet and mash forms with different CP levels of 205.0 g/kg (H, high), 187.5 g/kg (M, intermediate) and 175.0 g/kg (L, low) in the grower phase and 195.0 g/kg (H), 180.0 g/kg (M) and 165.6 g/kg (L) in the finisher phase. Individual amino acids (AA) were supplemented to maintain digestible AA-to-digestible lysine ratios. Decreasing dietary CP content to 187.5 g/kg in the grower phase and 180.0 g/kg in the finisher phase reduced NH3 concentrations at litter level (P < 0.001), but a further reduction in dietary CP had no additional effect. Mash treatments had better litter qualities and lower incidences of foot and hock lesions than pellet treatments at d 38 (P < 0.001). In addition, treatments with reduced CP had lower incidence of foot lesions at d 38 (P < 0.001). Broilers fed pelleted diets had higher ADFI, ADG, and final BW, improved feed conversion ratio (FCR), and heavier carcasses (P < 0.001) than those fed mash diets over a production period of 39 d. Performance could not be maintained when birds were fed L CP pelleted diets. This study demonstrated that, with the supplementation of AA to meet requirements, the concentration of dietary CP can be reduced to 187.5 and 180.0 g/kg in the grower and finisher phases respectively, without impairing broiler performance, meat yield and quality. Mash diets were favorable when considering the overall litter quality and welfare of the birds. However, they could not maintain the same broiler performance and slaughter yield as pelleted diets. Results from the present study may assist the poultry sector towards a socially acceptable low-emission farming system.

Effect of Diet Composition on Excreta Composition and Ammonia Emissions from Growing-Finishing Pigs.

Simple SummaryPig production leads to high levels of ammonia emissions, which in turn causes environmental pollution. This paper, therefore, looks at the possibilities for reducing ammonia emissions. Reducing ammonia precursors in diets and acidifying the urine and manure pH by acidifying diets make it possible to reduce the ammonia emissions from pig production facilities. The present study tested the impact of decreased crude protein or acidifying diets on urine and manure composition and ammonia emissions from growing and finishing pig houses. We found that decreasing dietary crude protein levels reduced the ammonia emissions from the floor as well as from the pig houses, whereas acidifying diets failed to reduce ammonia emissions from the floor and the pig houses. Reducing dietary crude protein is, therefore, a positive solution to reduce ammonia emissions from pig houses.This study aimed to investigate the impact of decreased crude protein (CP) levels (by 2% units) or acidifying diets (by adding 10 g benzoic acid/kg diet in combination with replacing a part of CaCO3 by about 10 g Ca-formate/kg diet) on urine, feces and manure composition and ammonia emissions from growing and finishing pig houses. Yorkshire x F1(Landrace x Yorkshire) pigs (n = 576) with an initial body weight of 24.9 ± 3.4 kg were randomly allocated to four treatments of (i) a control diet with normal protein content and no acidifying components added; (ii) a diet with 2% units CP reduction; (iii) a diet with an acidifying effect on the manure; (iv) or a diet consisting of a combination of diet (ii) and (iii). Pigs were housed in four mechanically ventilated and temperature-controlled rooms. Results showed that decreasing the dietary CP levels by 2% units reduced the ammonia emission from the floor by 46% (p = 0.06) and from the pig house by 31% (p = 0.08). Decreased CP diets reduced the total N in feces and in manure and NH4-N in the manure, as well as the ammonia concentration at 1 cm and 10 cm above the manure surface (p < 0.05). However, acidifying diets failed to reduce ammonia emissions from the floor and the pig house (p > 0.05). Reducing dietary crude protein is, therefore, a solution to reducing ammonia emissions from pig houses.

Use of visible-near infrared spectroscopy to predict nutrient composition of poultry excreta

Nowadays optimal feed formulation for poultry is sought for available content, which takes into account how the nutrients are digested and metabolized by the animal. The digestibility coefficients of the nutrients are usually obtained in in vivo trials that require feeding the birds with different diets of well-known composition and analyzing a large number of excreta samples. Nutrient excreta composition is usually found by wet analytical methods. This work presents visible-near infrared (Vis-NIR) calibrations for organic matter, protein, fat, gross energy, uric acid and phosphorus in excreta from bioassays involving broiler chickens, laying hens and broiler turkeys carried out between 2017 and 2020. The Vis-NIR spectra (400–2499.5 nm) were pretreated by generalized least squares weighting (GLSW) and partial least squares regression (PLSR) was used to obtain the prediction models. The six parameters were properly predicted with the values of ratio of performance of deviation (RPD) and coefficient of determination of prediction (R2p) of the validation set ranging from 3.7 to 4.6 and from 0.91 to 0.95 respectively. All but one of the calibrations passed the statistical tests for fit for purpose described in ISO 12099:2017. Despite the global calibrations provided satisfactory results, specific calibrations for broiler chicken excreta and for laying hen excreta were developed to check if their predictions could be even better but the results did not improve. Finally, the root mean square error of prediction (RMSEP) of the global calibrations was compared with the standard error of the reference methods employed for the analysis of these parameters, confirming their high performance and direct applicability.

Effect of Feeding Low Protein Diets on the Production Traits and the Nitrogen Composition of Excreta of Broiler Chickens

The main goal of the current study was to investigate the effects of feeding low protein (LP) diets on the performance parameters and excreta composition of broiler chickens. In total, 288 male Ross 308 day-old chickens were divided into two dietary treatment groups using six replicate pens with 24 chickens each. No LP diet was fed in the starter phase. The protein reduction in the grower and finisher phases were 1.8% and 2% respectively. Beside the measurements of production traits, on day 24 and 40 representative fresh excreta samples were collected, their dry matter, total N, NH4+-N and uric acid-N contents determined, and the ratio of urinary and fecal N calculated. Dietary treatments failed to cause significant differences in the feed intake, growth rate, and feed conversion ratio of animals. LP diets decreased the total nitrogen and uric acid contents of excreta significantly. The age of birds had also significant effect, resulting more reduction in the grower phase compared with the finisher. The ratio of urinary N was higher at day 40 compared with the age of day 24. The urinary N content of broiler chicken’s excreta is lower than can be found in the literature, which should be considered in the ammonia inventory calculations.

Laying Hens Biochar Diet Supplementation—Effect on Performance, Excreta N Content, NH3 and VOCs Emissions, Egg Traits and Egg Consumers Acceptance

Sustainable solutions for intensive poultry production can help farmers, rural communities, consumers, and regulatory agencies. This study assessed supplementation of laying hens diet with beechwood biochar (BC, 1~2%) and BC–aluminosilicates–glycerin mixture (BCM, 1.5~3%) to lower the environmental impact while maintaining egg quality. The effect on feed intake, laying performance, egg quality, the sensory quality of hardboiled eggs, ammonia (NH3) and volatile organic compound (VOC) emissions from excreta, and the excreta composition, were evaluated. A total of 90 hens were distributed into 30 cages and divided into five groups (n=6 replications). BC addition increased daily feed intake, while 1.5% BCM addition reduced it. The influence on egg parameters was positive, with a 6% increase in laying performance, up to 10% and 6% increase in shell resistance to crushing and shell thickness, respectively. The sensory analysis demonstrated no significant differences between all treatments. Excreta total N content was numerically lower due to the treatments (by 4~20%); its pH increased (not significantly), while no effect on ammoniacal N and dry matter content was observed. Most of the investigated treatments had a numerically positive (not statistically significant) effect on NH3 reduction. The reduction of VOC emissions was ambiguous and not statistically significant.

Elucidating three-way interactions between soil, pasture and animals that regulate nitrous oxide emissions from temperate grazing systems

Pasture-based livestock farming contributes considerably to global emissions of nitrous oxide (N2O), a powerful greenhouse gas approximately 265 times more potent than carbon dioxide. Traditionally, the estimation of N2O emissions from grasslands is carried out by means of plot-scale experiments, where externally sourced animal excreta are applied to soils to simulate grazing conditions. This approach, however, fails to account for the impact of different sward types on the composition of excreta and thus the functionality of soil microbiomes, creating unrealistic situations that are seldom observed under commercial agriculture. Using three farming systems under contrasting pasture management strategies at the North Wyke Farm Platform, an instrumented ruminant grazing trial in Devon, UK, this study measured N2O emissions from soils treated with cattle urine and dung collected within each system as well as standard synthetic urine shared across all systems, and compared these values against those from two forms of controls with and without inorganic nitrogen fertiliser applications. Soil microbial activity was regularly monitored through gene abundance to evaluate interactions between sward types, soil amendments, soil microbiomes and, ultimately, N2O production. Across all systems, N2O emissions attributable to cattle urine and standard synthetic urine were found to be inconsistent with one another due to discrepancy in nitrogen content. Despite previous findings that grasses with elevated levels of water-soluble carbohydrates tend to generate lower levels of N2O, the soil under high sugar grass monoculture in this study recorded higher emissions when receiving excreta from cattle fed the same grass. Combined together, our results demonstrate the importance of evaluating environmental impacts of agriculture at a system scale, so that the feedback mechanisms linking soil, pasture, animals and microbiomes are appropriately considered.

Modeling the Effect of Nutritional Strategies for Dairy Cows on the Composition of Excreta Nitrogen

For an integrated evaluation of the effect of nutritional strategies on the utilization and losses of N at dairy farms, reliable estimates of excreta production and composition are indispensable. An extant, dynamic, mechanistic model of rumen functioning was extended with static equations that describe intestinal digestion to simulate the composition of dairy cow feces and urine as a function of diet composition. The extended model predicts organic matter (OM), carbon (C), and nitrogen (N) output of both feces and urine, classified in different components. Total N excretion was partitioned in three fractions based on the C:N ratio of individual components representing their availability of N following manure application to crops, viz. NM (immediately available), NE (easily decomposable), and NR (resistant). Forty nutritional strategies for stall-fed dairy cows, covering diets with a wide range in protein content and OM digestibility, were evaluated. The simulated ranges in fecal and urinary composition were largely in line with values reported in literature. Diet intake and composition had a substantial effect on simulated total N excretion and excreta composition, mainly because of differences in the level of NM excretion and the C:N ratio of the NR fraction. Furthermore, it was shown that the type of OM excreted varies considerably between different diets. A simplified simulation of degradation processes during the first 4 months of excreta storage produced average values and ranges of slurry characteristics that were in line with values reported in literature. The simulated variation in slurry characteristics suggested a strong variability in ammonia N losses from the slurry pit and a moderate variability in plant availability of slurry N. Further efforts are required to integrate effects of manure storage conditions on the storage processes. In conclusion, the model can be a tool to predict fecal and urinary composition of cattle, and ultimately to improve the utilization of N from field applied manure as well as to evaluate the effects of different nutritional strategies on the whole-farm N balance.

Evaluation of golden needle mushroom (&lt;i&gt;Flammulina velutipes&lt;/i&gt;) stem waste on pullet performance and immune response

The driving force behind the interest in using natural herbs in poultry production is to eliminate the use of low-dose antibiotics. Therefore, this study was carried out to investigate the effect of Flammulina velutipes mushroom waste (FVW) on performance parameters, relative organ weight, apparent nutrient retention, excreta composition, immune response and serum immunity in pullets. A total of 360 x 10-week-old ISA Brown pullets were randomly assigned to five equal treatment groups, with nine replications of eight birds for each treatment. The dietary treatments included a standard basal diet as control; antibiotic (0.05% flavomycin); 2% FVW; 4% FVW; and 6% FVW. The total experimental duration was 42 days, from 10 weeks to 16 weeks old. Final live weight was higher in FVW groups than in the control and antibiotic groups. No differences were found for average daily feed intake, average daily weight gain and feed conversion ratio during the entire study period. Proventriculus weight and bursa weight were higher in FVW groups. No differences were observed for other inner relative organ weights (liver weight, gizzard weight spleen and abdominal fat weight) compared with the control and antibiotic groups. Dietary inclusion of FVW increased dry matter, crude protein and ether extract retention compared with control and antibiotic groups. Excreta dry matter content was higher and pH lower, in the FVW groups than in the control and antibiotic groups. Antibody titres against Newcastle disease, Infectious bronchitis and Avian influenza virus vaccines were higher in FVW groups. Serum immunoglobulin parameters (IgA, IgG, IgM) were higher in FVW than in the control and antibiotic groups. Flammulina velutipes mushroom waste can be used at inclusion levels up to 6% in pullet rations for better immune response and nutrient retention without hampering normal growth performance. Keywords : Antibody titres, apparent nutrient retention, excreta dry matter, serum immunity

Chemical composition of excreta of blue rock pigeon (Columba livia) from urban niches of agricultural region

Chemical composition of excreta of blue rock pigeon (<i>Columba livia</i>) from urban niches of agricultural region

The Fatty Acid Composition of Excreta of Broiler Chickens Fed Different Dietary Fatty Acids

The Fatty Acid Composition of Excreta of Broiler Chickens Fed Different Dietary Fatty Acids

A by-product of swine slaughtering as a protein source in broiler diets: effects on performance, composition of excreta, litter quality and on foot pad health.

Foot pad dermatitis (FPD) is of great concern in poultry industry, and dietary strategies are needed to improve foot pad health because of animal welfare and economic reasons. As the main factor for the development of FPD is the DM content of litter (consisting mainly of excreta; Kamphues etal., 2011), there are different dietary approaches to influence this disease pattern. In two consecutive trials, a total of 200 broilers were kept from day 7 until the 35th day of life. They were divided into four groups at each trial and fed with one of four experimental diets, based on wheat and corn mainly, but differing in the protein source: Group 1 was fed a diet with soya bean meal (SBM) as the main protein source, whereas Group 2, Group 3 and Group 4 were assigned to diets with 4, 8 and 12% of a protein-rich (66.7% CP in DM) by-product of swine slaughtering [Swine Protein Meal (SPM); in exchange for SBM]. The inclusion of 12% SPM resulted in a decreased dietary potassium content of about 3g/kg diet (Group 1 vs. 4). Increasing dietary levels of the by-product (8 and 12%) led to lowered feed intake (Group 1 vs. 4: ~10%) and weight gain (Group 1 vs. Group 4: ~8.5%). Although highest DM contents of excreta and litter were determined in Group 4, foot pad health was not influenced positively as hypothesized. Remarkable was the observed 'stickiness' of excreta when the by-product was included in the diet at increasing levels, presumably due to the high proportion of bones in the by-product. In conclusion, substituting SBM by 4% of the by-product of swine slaughtering in broiler diets did not impair performance parameters, but led to the most favourable foot pad scores in this study.

Comparison of growth performance and excreta composition in broiler chickens when ranked according to various feed efficiency metrics.

Several feed efficiency (FE) metrics are currently used in livestock production to select for improved FE. Whether or not different FE metrics similarly estimate physiological characteristics in chickens of diverging FE has not been reported so far. This study aimed to assess potential differences in feed intake (FI), performance, and nutrient excretion in broiler chickens of diverging FE when ranked according to their residual FI (RFI), residual BW gain (RBG), RFI and BW gain (RIG), and G:F between d 7 and 35 of life. The FI was determined daily and BW was recorded once a week. The ranking of chickens into good, medium, and poor FE groups was completed separately for each FE metric. Freshly dropped excreta were collected for pH and DM measurements on d 30 to 32 of life and total excreta for determination of nutrient excretion was collected on d 34 to 36 of life. Relationships among FE metrics were evaluated using regression analysis showing that RFI, RIG, and G:F were more related to each other than to RBG. The FE values greatly varied among chickens for all FE metrics and chickens did not always cluster within the same FE group when using RFI, RIG, RBG, and G:F as the FE metrics because of the calculation approaches. Due to sex-related differences in performance, data of male and female chickens were analyzed separately. The RFI and RIG metrics showed a linear increase ( < 0.01) in total FI from good to poor FE in male and female chickens, whereas G:F showed this effect ( ≤ 0.011) only when BW gain was standardized to 1,500 g. The RBG did not clearly select chickens of enhanced total BW gain and only tended ( < 0.1) to select for greater BW gain from good to poor FE in female chickens. Excreta pH linearly decreased by 0.7 log units and DM content increased in males from good to poor FE when using RFI and RIG, respectively ( < 0.01). In both sexes, RFI ( < 0.05) and RIG metrics ( ≤ 0.06) showed a linear increase in daily nitrogen excretion from good to poor FE. In conclusion, results demonstrate that selection of the metric used to determine the FE of chickens modified the results obtained for comparison of production parameters and nutrient excretion among FE groups. Thereby, the RFI, RIG, and G:F metrics were beneficial in selecting the most feed efficient chickens to reduce feed costs, whereas the use of RFI and RIG may be better to select chickens with improved nitrogen retention and thus reduced excretion of an environmental pollutant.

Stoichiometry of Excreta and Excretion Rates of a Stream-dwelling Plethodontid Salamander

Nutrient recycling by fish and amphibians can contribute significantly to ecosystem processes in freshwater ecosystems. Variation in the components that comprise excreta and the factors that control excretion rates may result in differences in the rates and ratios of nutrients excreted by these taxa. These factors can subsequently influence the ecological role of fish and amphibians in freshwater systems. We assessed the composition of excreta of larval Eurycea cirrigera in six headwater streams, and investigated the influence of body size, organismal stoichiometry, and stream nutrient concentrations on mass-specific excretion rates. Excretion components and excretion rates of E. cirrigera were compared to fish in stream and river systems. Excretion of urea comprised the majority of excreted waste in E. cirrigera. This is considerably different from freshwater fish, where the majority of excreted nitrogenous waste is in the form of NH4. Excretion of NH4, soluble reactive phosphorus (SRP), and urea by E. c...

Black soldier fly as dietary protein source for broiler quails: apparent digestibility, excreta microbial load, feed choice, performance, carcass and meat traits

In order to expand with validated scientific data the limited knowledge regarding the potential application of insects as innovative feed ingredients for poultry, the present study tested a partial substitution of soya bean meal and soya bean oil with defatted black soldier fly (Hermetia illucens) larvae meal (H) in the diet for growing broiler quails (Coturnix coturnix japonica) on growth performance, mortality, nutrients apparent digestibility, microbiological composition of excreta, feed choice, carcass and meat traits. With this purpose, a total of 450 10-day-old birds were allocated to 15 cages (30 birds/cage) and received three dietary treatments: a Control diet (C) and two diets (H1 and H2) corresponding to 10% and 15% H inclusion levels, respectively (H substituted 28.4% soya bean oil and 16.1% soya bean meal for H1, and 100% soya bean oil and 24.8% soya bean meal for H2, respectively). At 28 days of age, quails were slaughtered, carcasses were weighed, breast muscles were then excised from 50 quails/treatment, weighed, and ultimate pH (pHu) and L*, a*, b* colour values were measured. Breast muscles were then cooked to assess cooking loss and meat toughness. For the digestibility trial, a total of 15 28-day-old quails were assigned to the three feeding groups. The excreta samples were subjected to chemical and microbiological analysis. The same 15 quails were then simultaneously provided with C and H2 diets for a 10-day feed choice trial. Productive performance, mortality and carcass traits were in line with commercial standards and similar in all experimental groups. With the exception of ether extract digestibility, which was lower in H1 group compared with C and H2 (P=0.0001), apparent digestibility of dry matter, CP, starch and energy did not differ among treatments. Microbial composition of excreta was also comparable among the three groups. Feed choice trial showed that quails did not express a preference toward C or H2 diets. Breast meat weight and yield did not differ among C, H1 and H2 quails. Differently, the inclusion of H meal reduced meat pHu compared with C. In conclusion, this study demonstrated that H. illucens larvae meal can partially replace conventional soya bean meal and soya bean oil in the diet for growing broiler quails, thus confirming to be a promising insect protein source for the feed industry. Further research to assess the impact of H meal on intestinal morphology as well as on meat quality and sensory profile would be of utmost importance.

Impact of pig diets with different fibre contents on the composition of excreta and their gaseous emissions and anaerobic digestion

Two diets with the same net energy and digestible lysine content were compared in growing pigs: a control diet with soybean meal as the main protein source, and an experimental high fibre (HF) diet with 15% of dried distiller's grain with solubles and 15% rapeseed meal as the main protein source. The animals (10 castrated males) were housed individually in metabolism cages, and urine and faeces were collected separately from each pig in order to measure nutrient digestibility and the excretory patterns of nitrogen (N) and carbon (C). Ammonia (NH3) volatilisation was measured from samples of slurry and urine, over a 16-day storage period in a laboratory pilot scale system. The methane (CH4) production from effluents (fresh faeces and slurry) was measured using three methods: a biomethanogene test to obtain the ultimate CH4 potential (B0), a simulation of storage over 100 days, and with a lab scale anaerobic digester. The addition of biofuel by-products as fibre source had no significant effect on the animal growth performance, but it significantly reduced organic matter (OM), N and C digestibility by 7%, 8% and 9%, respectively. The HF diet significantly increased the amount of faeces excreted by 40%, whereas the amount of urine was not affected. Concurrently, the HF diet significantly increased the C content of the faeces by 51% and the amount of OM excreted per pig by 65%, compared to the control diet. NH3 emissions from slurry and urine were significantly reduced for the HF diet by 31% and 26%, respectively, compared to the control diet. The B0 expressed in L CH4kg−1 OM was not affected by the type of diet. During the simulation of storage, the CH4 production expressed in L CH4kg−1 OM was significantly affected by the diet and the type of effluent. With the lab-scale anaerobic digester, CH4 production per kg OM was higher for faeces than for slurry (333Lkg−1 OM vs. 219Lkg−1 OM, respectively) whereas the difference between the HF and the control diet was small.

Effect of different quality wheat dried distiller's grain solubles (DDGS) in pig diets on composition of excreta and methane production from faeces and slurry

This study was conducted to investigate the effects of the incorporation in pig diets of 25% of ten different wheat dried distiller's grain solubles (DDGS) from biofuel production, on (i) the excretion of organic matter (OM), nitrogen (N) and carbon (C), and (ii) on the potential of methane (CH4) emission from effluents (faeces and slurry). Eleven experimental diets were formulated: a control diet mainly based on cereals and soybean meal, and ten experimental diets obtained by adding to the control diet 25% of one of the ten samples of DDGS. The DDGS differed by their origin and the process of biofuel production. They were classified according to a colour score used as an indicator of processing conditions. The ultimate methane potential of effluents (B0, expressed in L CH4/kg OM) was measured for each diet in anaerobic storage conditions over 100days. The addition of DDGS to pig diets increased the amount of faeces excreted by 27 to 50% and the amount of slurry excreted by 7 to 50%, compared to the control diet. The OM excretions in faeces and in slurry were significantly increased by 59% and 75% respectively, with wheat DDGS inclusion, compared to the control diet. As for total N and C excretory patterns, the addition of wheat DDGS increased their excretions by 65% and 54%, respectively, compared to the control diet. The results indicated that the partitioning of N was shifted from urine to faeces with the inclusion of fibre from wheat DDGS. B0 values measured on faeces and slurry were respectively in a range from 202 to 294 and from 278 to 368L CH4/kg OM. On average, B0 values were lower for the effluents from the DDGS diets compared to the effluent from the control diet. The type of DDGS also affected the B0, with lower values obtained for dark compared to medium or light DDGS. When methane emission was expressed per pig and per day, potential productions for slurry and faeces from the control diet were 51 and 68L/day, respectively. On average, the values were significantly higher, by about 40%, for slurry and faeces from DDGS diets, with 72 and 98L/day, respectively. It was concluded that the heating process of DDGS may reduce the methane production potential of their indigestible OM. However, because of the increased OM excretion, incorporating DDGS in pig diets increases the potential methane production per pig produced.

Recycling of livestock manure in a whole-farm perspective

Intensification increases the environmental impact of livestock production systems. Efforts to recycle nutrients in livestock manure for crop production will effectively reduce several pollution problems, although general solutions are difficult to devise in view of the diversity in production systems, management strategies and legislation between countries and regions. This paper argues that a whole-farm perspective taking side-effects and on-farm interactions into account is needed to determine the cost-effectiveness of strategies to mitigate pollution from livestock manure management. Animal feeding plays a key role in the control of nutrient flows on livestock farms, since the diet affects the composition of excreta. There is a great potential for manipulating manure composition by diet manipulations. Manure is a significant source of heavy metals in soil, and in Europe the permitted levels of Cu and Zn in livestock diets have been lowered to reduce their environmental impact. A variety of environmental technologies are being developed for treatment of manure, many of which have a significant potential for reducing nutrient losses. Internationally agreed and enforced regulations that link pollution control with the adoption of best available technologies could provide the demand that is needed to drive research and development. In the past, policy-makers have typically focused on individual environmental problems. It is essential, however, that the efforts to close nutrient cycles on the farm are accompanied by a corresponding reduction in total inputs, otherwise losses after field application will increase. Integrated assessment tools are needed which can evaluate all internal flows of nutrients, imports and exports, energy use, hygienic risks and contaminants, as well as costs, at the farm-scale and beyond. It is important to consider pollution control strategies for a farm in the framework of local and regional pollution control planning.