Search

[EN] Variations in phosphorous (P) digestibility as a function of methodology, phosphate source, physicochemical characteristics and commercial source were evaluated in broilers. Three methodologies and two phosphates (monocalcium phosphate, MCP, and dicalcium phosphate, DCP) from three different commercial sources were used in two experiments. In the first experiment, MCP and DCP were incorporated into a P-deficient diet at two levels of inclusion and P digestibility was evaluated using three methodologies of the regression method (total excreta, marker in excreta and prececal digestibility). In the second experiment, variations in P digestibility of six phosphate sources (three MCP and three DCP) were evaluated using the total collection method. The P digestibility of MCP ranged from 75.2 to 87.4% and from 80.5 to 86.6% for DCP amongst methodologies (p > 0.05). Particle size, surface area, degree of crystallinity and impurities varied amongst commercial sources. The P digestibility of the three tested commercial sources of MCP was 79.6% (MCP1), 70.2% (MCP2) and 65.6% (MCP3); p > 0.05. The P digestibility of the three tested commercial sources of DCP was 80.1% (DCP1), 77.4% (DCP2) and 71.4% (DCP3); p > 0.05. The objective of this study was to compare the total tract (total excreta and marker) and prececal methodologies to determine phosphorus (P) digestibility and to evaluate its variation as a function of the physicochemical characteristics of the inorganic phosphate used (monocalcium, MCP and dicalcium, DCP) from different commercial sources. A total of 176 1-day-old male broilers were used in two digestibility experiments. In Experiment 1, one MCP and one DCP were incorporated in the basal diet at two levels. In Experiment 2, MCP and DCP from three commercial sources were incorporated to the basal diet at one level. Physicochemical characteristics of inorganic phosphates were examined, as well. Additionally, bone mineralization and growth performance traits were

Pig slurry is a valuable fertilizer for crop production but at the same time its management may pose environmental risks. Slurry samples were collected from 77 commercial farms of four animal categories (gestating and lactating sows, nursery piglets and growing pigs) and analyzed for macronutrients, micronutrients, heavy metals and volatile fatty acids. Emissions of ammonia (NH3) and biochemical methane potential (BMP) were quantified. Slurry electrical conductivity, pH, dry matter content and ash content were also determined. Data analysis included an analysis of correlations among variables, the development of prediction models for gaseous emissions and the analysis of nutritional content of slurries for crop production. Descriptive information is provided in this work and shows a wide range of variability in all studied variables. Animal category affected some physicochemical parameters, probably as a consequence of different slurry management and use of cleaning water. Slurries from gestating sows and growing pigs tended to be more concentrated in nutrients, whereas the slurry from lactating sows and nursery piglets tended to be more diluted. Relevant relationships were found among slurry characteristics expressed in fresh basis and gas emissions. Predictive models using on-farm measurable parameters were obtained for NH3 (R2 = 0.51) and CH4

[EN] Forty pigs of 76.8 +/- 4.2 kg body weight were fed four different diets varying in ensiled citrus pulp (ECP) inclusion level (0, 50, 100, and 150 g of ECP/kg of diet on dry matter base). The trial lasted 5 weeks. During the last week, faecal samples were obtained to calculate apparent nutrient digestibility; also volatile fatty acids (VFA) content in faeces was determined. The digestible energy and protein of ECP was estimated by regression analysis. During the trial faecal samples were collected to determine enterobacteria and lactobacilli counts. At slaughter, carcass characteristics were registered. The inclusion of ECP in the diets decreased energy digestibility but increased neutral and acid detergent fibre digestibility linearly (p<0.05). The estimated digestible energy and protein of ECP were lower than expected (7.0 MJ/kg dry matter (DM) and 33.8 g/kg DM, respectively). Total VFA production in faeces was not affected by the diet. Both enterobacteria and lactobacilli counts were lower (p<0.01) with than without ECP inclusion at the end of the study. Carcass yield decreased linearly (p<0.05) and backfat at gluteus medius increased quadratically (p<0.05) with the inclusion of ECP in the diet. The polyunsaturated fatty acid content of the internal subcutaneous fat layer decreased quadratically (p<0.05) with the inclusion of ECP. Thus, the nutritive value of ECP for finishing pigs is low and levels of 150g/kg can negatively affect carcass yield. However, including up to 100 g of ECP/kg in finishing pig diets did not affect nutrient digestibility, carcass yield and subcutaneous fat FA profile. Additionally, increasing ECP levels in diets decreases faecal enterobacteria and lactobacilli counts in faeces

[EN] This study aimed to analyse several factors of variation of slurry composition and to establish prediction equations for potential methane (CH4) and ammonia (NH3) emissions. Seventy-nine feed and slurry samples were collected at two seasons (summer and winter) from commercial pig farms sited at two Spanish regions (Centre and Mediterranean). Nursery, growing-fattening, gestating and lactating facilities were sampled. Feed and slurry composition were determined, and potential CH4 and NH3 emissions measured at laboratory. Feed nutrient contents were used as covariates in the analysis. Near infrared reflectance spectroscopy (NIRS) was evaluated as a predicting tool for slurry composition and potential gaseous emissions. A wide variability was found both in feed and slurry composition. Mediterranean farms had a higher pH (p<0.001) and ash (p=0.02) concentration than those located at the Centre of Spain. Also, type of farm affected ether extract content of the slurry (p=0.02), with highest values obtained for the youngest animal facilities. Results suggested a buffer effect of dietary fibre on slurry pH and a direct relationship (p<0.05) with fibre constituents of manure. Dietary protein content did not affect slurry nitrogen content but decreased (p=0.003) total and volatile solids concentration. Prediction models of potential NH3 emissions (R2=0.89) and CH4 yield (R2=0.61) were obtained from slurry composition. Predictions from NIRS showed a high accuracy for most slurry constituents (R2 above 0.90) and similar accuracy of prediction of potential NH3 and CH4 emissions (R2=0.84 and 0.68, respectively) to models using slurry characteristics, which can be of interest to estimate emissions from commercial farms and establish mitigation strategies or optimize biogas production.

This study aimed to analyse several factors of variation of slurry composition and to establish prediction equations for potential methane (CH4) and ammonia (NH3) emissions. Seventy-nine feed and slurry samples were collected at two seasons (summer and winter) from commercial pig farms sited at two Spanish regions (Centre and Mediterranean). Nursery, growing-fattening, gestating and lactating facilities were sampled. Feed and slurry composition were determined, and potential CH4 and NH3 emissions measured at laboratory. Feed nutrient contents were used as covariates in the analysis. Near infrared reflectance spectroscopy (NIRS) was evaluated as a predicting tool for slurry composition and potential gaseous emissions. A wide variability was found both in feed and slurry composition. Mediterranean farms had a higher pH (p<0.001) and ash (p=0.02) concentration than those located at the Centre of Spain. Also, type of farm affected ether extract content of the slurry (p=0.02), with highest values obtained for the youngest animal facilities. Results suggested a buffer effect of dietary fibre on slurry pH and a direct relationship (p<0.05) with fibre constituents of manure. Dietary protein content did not affect slurry nitrogen content but decreased (p=0.003) total and volatile solids concentration. Prediction models of potential NH3 emissions (R2=0.89) and CH4 yield (R2=0.61) were obtained from slurry composition. Predictions from NIRS showed a high accuracy for most slurry constituents (R2>0.90) and similar accuracy of prediction of potential NH3 and CH4 emissions (R2=0.84 and 0.68, respectively) to models using slurry characteristics, which can be of interest to estimate emissions from commercial farms and establish mitigation strategies or optimize biogas production.

[EN] Anaerobic co-digestion of pig slurry with four agricultural substrates (tomato, pepper, persimmon and peach) was investigated. Each agricultural substrate was tested in co-digestion with pig slurry at four inclusion levels: 0%, 15%, 30% and 50%. Inclusion levels consisted in the replacement of the volatile solids (VS) from the pig slurry with the VS from the agricultural substrate. The effect of substrate type and inclusion level on the biochemical methane potential (BMP) was evaluated in a batch assay performed at 35 C for 100 days. Agricultural substrate s chemical composition was also analyzed and related with BMP. Additionally, Bacteria and Archaea domains together with the four main methanogenic archaeal orders were quantified using quantitative real-time TaqMan polymerase chain reaction (qPCR) at the end of the experiment to determine the influence of agricultural substrate on sludge s microbial composition. Results showed that vegetable substrates (pepper and tomato) had higher lipid and protein content and lower carbohydrates than fruit substrates (persimmon and peach). Among substrates, vegetable substrates showed higher BMP than fruit substrates. Higher BMP values were obtained with increasing addition of agricultural substrate. The replacement of 50% of VS from pig slurry by tomato and pepper increased BMP in 41% and 44%, respectively compared with pig slurry only. Lower increments in BMP were achieved with lower inclusion levels. Results from qPCR showed that total bacteria and total archaea gene concentrations were similar in all combinations tested. Methanomicrobiales gene concentrations dominated over the rest of individual archaeal orders

[EN] The effects of including rapeseed meal (RSM) as an alternative source of vegetable protein in pig diets on animal performance, nutrient digestibility and methane production from faeces was investigated. A total of 96 pigs of 42.4 (±4.04) kg of body weight (BW) were allocated into two dietary treatments (48 animals/treatment). One group was fed a conventional diet (C) and the other with a diet containing RSM (R). The level of RSM in the R diet was 120 g/kg during the growing phase (40 70 kg BW; days 1 34 of study) and 200 g/kg during the finishing phase (70 114 kg BW; days 35 76 of study). Average daily gain (ADG), average daily feed intake and feed conversion ratio were measured throughout the study. During the finishing phase, faeces were collected and analysed for dry matter (DM), organic matter (OM), crude protein (CP), crude fat, fibre fractions, pH, volatile fatty acids and biochemical methane potential (B0). Additionally, the coefficient of total tract apparent digestibility (CTTAD) of nutrients was measured using the acid-insoluble ash method. At slaughter (114 ± 12.2 kg BW), the main carcass and meat quality characteristics were registered and the fatty acid (FA) profile of the subcutaneous fat and muscle was analysed. During the growing phase, R animals showed lower ADG compared with C animals (818 vs. 890 g/d; P<0.05). These differences disappeared during the finishing phase. Faeces from treatment R showed a lower B0 compared to those from treatment C (308 vs. 351 mL methane/g OM). Animals from R group showed a lower DM, OM and CP CTTAD than C animals (0.790, 0.826 and 0.729 vs. 0.832, 0.865 and 0.818, respectively; P<0.05) and tended to show lower fibre digestion rates. Consequently, animals from R group showed a higher amount of these components in faeces. However, fat digestion was not affected. No differences were found between treatments on most carcass characteristics. Overall, the inclusion of high levels of RSM in pig diets decreased final BW

[EN] Sludge physicochemical composition, methane (CH4) yield, and methanogenic community structure and dynamics using quantitative real-time polymerase chain reaction were determined after start-up of anaerobic digestion of pig manure. Eight thermophilic continuous stirred anaerobic digesters were used during 126 days. Four management strategies were investigated: a feedless and a non-feedless period followed by a gradual or an abrupt addition of pig manure (two digesters per strategy). During the first 43 days, VFA (volatile fatty acids) accumulations and low CH4 yield were observed in all digesters. After this period, digesters recovered their initial status being propionic acid the last parameter to be reestablished. Non-feedless digesters with an abrupt addition of pig manure showed the best performances (lower VFA accumulation and higher CH4 yield). Differences in microbial orders and dynamics, however, were less evident among treatments. Hydrogenotrophic methanogenesis, Methanomicrobiales first and Methanobacteriales second, was the dominant metabolic pathway in all digesters. Further research is needed to clarify the role and activity of hydrogenotrophic methanogens during the recovery start-up period and to identify the best molecular tools and methodologies to monitor microbial populations and dynamics reliably and accurately in anaerobic digesters

[ES] Un equipo de investigadores del Instituto de Ciencia y Tecnología Animal (ICTA), perteneciente a la Universitat Politècnica de València (UPV), junto con el Centro de Investigación y Tecnología Animal (CITA), perteneciente al Instituto Valenciano de Investigaciones Agrarias (IVIA), ha desarrollado un proyecto de valorización energética de purines de cerdo y subproductos agrícolas mediante co-digestión anaerobia.