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Trioza erytreae (Del Guercio) (Hemiptera: Triozidae) is one of the vectors of the citrus greening or huanglongbing (HLB) disease, the most devastating citrus disease globally. A classical biological control program has been established to control this vector in Europe, where it has been threatening the citrus industry since its detection in mainland Spain and Portugal. For this, its main parasitoid Tamarixia dryi (Waterson) (Hymenoptera: Eulophidae) has been introduced. Here, we evaluated the nutritional value of T. erytreae honeydew as a suitable food source for T. dryi. This solid honeydew is the most abundant food source for the parasitoid in the field. Our results demonstrated that T. erytreae honeydew enhanced the longevity of T. dryi compared to other diets such as water, ‘sucrose alone’ or ‘sucrose + protein’. Females fed on honeydew also oviposited more eggs than those fed on water or ‘sucrose alone’. Finally, T. dryi fed on honeydew tended to parasitize more psyllids than those fed on the other diets. Chemical analyses demonstrated that T. erytreae honeydew contains proteins, and this can explain the increase in egg load of honeydew fed parasitoids. Further research is necessary to understand why these females tended to parasitize more than females fed on ‘sucrose + protein’. Overall, these results contribute to understanding the successful and rapid establishment of T. dryi in Europe and to the successful rearing and release programs in newly invaded areas.

El control de plagas en agricultura se basa mayoritariamente en el uso de insecticidas que pueden producir efectos nocivos en insectos beneficiosos. En varios estudios recientes, se ha demostrado que la melaza excretada por los hemípteros que se alimentan de plantas tratadas con insecticidas sistémicos puede contaminarse con dichos insecticidas, y resultar tóxica para los insectos beneficiosos que se alimentan de ella. Esta ruta de exposición ha sido demostrada para tres especies de plantas distintas, cinco insecticidas sistémicos y cuatro especies de hemípteros, por lo que puede ser una ruta de exposición muy común en diferentes agroecosistemas donde el néctar es un recurso escaso y la melaza es la principal fuente de alimentación para los insectos beneficiosos.

Los neonicotinoides son los insecticidas sistémicos más ampliamente utilizados a escala global a pesar de que resultan tóxicos para los insectos beneficiosos que se alimentan de néctar o melaza. Varios estudios han demostrado que los insectos beneficiosos no son capaces de discriminar entre néctar contaminado y no contaminado con neonicotinoides. Sin embargo, esto nunca se ha comprobado para la melaza, la principal fuente de carbohidratos en muchos ecosistemas agrícolas. Para abordar esta cuestión, recogimos la melaza excretada por Planococcus citri Risso (Hemiptera: Pseudococcidae) que se habían alimentado de plantas tratadas y no tratadas con el neonicotinoide tiametoxam.

Este artículo se encuentra disponible en la siguiente URL: https://www.sciencedirect.com/science/article/pii/S1751731122002166 Using agricultural by-products such as dehydrated orange pulp (DOP) in animal feeds is of interest to increase pig sector sustainability. With this aim, an assay was carried out to assess the effects of increasing inclusion levels of DOP in pig diets regarding animal performance, carcass quality, and environmental impact. Four experimental diets were designed, a control diet (T1) and three more diets with increasing levels of DOP with 80, 160, and 240 g/kg of DOP for diets T2, T3, and T4, respectively. One hundred and sixty growing pigs were used in the experiment. Growth performance (average daily gain, ADG; average daily feed intake, ADFI and feed conversion ratio, FCR) and in vivo backfat thickness (BF) and loin depth (LD) gain were recorded during the finishing phase (from 70 to 130 kg BW). Faecal samples were incubated for bacteria enumeration. At slaughter, carcass characteristics and meat quality traits were measured, and subcutaneous fat was sampled to analyse the fatty acid (FA) profile. Additionally, the slurry excreted by the animals was measured, characterised and subjected to a gaseous emission assay during its storage. The final BW and overall ADFI, ADG and FCR were similar among treatments. In vivo final LD and BF gain decreased (P 0.10) as the inclusion level of DOP increased. No differences were observed in carcass characteristics with the inclusion of DOP, except carcass weight that decreased linearly (P = 0.05) with DOP. Regarding the FA profile of the subcutaneous fat, the ratio of total monounsaturated to saturated FA increased with the inclusion level of DOP. Neither slurry excretion and characterisation nor bacterial counts from faeces showed any significant difference among treatments. The inclusion of DOP led to greater CH4 emissions in mg per L of slurry and hour, whereas these differences disappeared when expressed in mg per animal and day. In all, it has been demonstrated that the inclusion of DOP up to 240 mg/kg in pig diets had minor effects on growth performance, carcass quality traits or gaseous emissions from slurry, favouring the circular economy strategy and pig sector sustainability.

[ES] Actualmente, la sostenibilidad del sector porcino depende de su capacidad para responder a la elevada demanda de productos ganaderos derivada del crecimiento de la población, adaptándose a los cambios en los contextos económico y político, y mejorando su rendimiento medioambiental mediante la mitigación de su impacto ambiental. En este contexto, el uso de subproductos agroindustriales ofrece materias primas alternativas en producción animal, con una menor carga ambiental asociada, en forma de piensos para el ganado, fuente de compuestos bioactivos o materias primas útiles en la producción de bioenergía. Esta tesis doctoral pretende evaluar el uso de subproductos agroindustriales mediterráneos como ingredientes en piensos para el ganado porcino o como co-substratos para la producción de biogás. Con este objetivo, se diseñaron y realizaron cuatro ensayos para evaluar el uso de subproductos de la industria del aceite de oliva y del zumo de naranja en alimentación porcina, evaluando su valor nutricional y las consecuencias de su inclusión sobre el rendimiento y la salud de los animales, la calidad del producto final y las emisiones de gases de los purines. Además, se realizó un ensayo para evaluar el efecto de cuatro sustratos agrícolas sobre el potencial bioquímico de metano (BMP) en co-digestión anaerobia con purines. Los resultados obtenidos a partir de los ensayos de valor nutricional indican que las tortas de aceituna y las pulpas de naranja ensayadas pueden ser incluidas en la dieta con cambios asociados en la excreción de nutrientes que conducen a modificaciones en las emisiones potenciales de amoníaco y BMP de los purines. En cuanto a los subproductos de la torta de aceituna, el ensayo de valor nutricional con tortas de aceituna crudas (COC) y parcialmente desgrasadas (PDOC) mostró que ambas tortas son fuentes apreciables de fibra insoluble, pero tienen un valor energético limitado (11.2 y 7.4 MJ/kg MS para COC y PDOC respectivamente) y un bajo valor como fuente de proteínas. En cambio, las pulpas de naranja deshidratadas (DOP) y ensilada secada al sol (ESDOP) ensayadas son una fuente de energía relevante (14.2 y 13.2 MJ/kg MS para DOP y ESDOP respectivamente) con valor añadido debido a su contenido en fibra soluble. En los ensayos de emisiones in vitro, los subproductos ensayados generaron una disminución en la excreción de N en la orina y, en el caso de la pulpa de aceituna, un aumento de la excreción de materia seca en heces. La emisión de amoniaco por kg de purín disminuyó con la inclusión de torta de aceituna y pulpa de naranja, mientras que el BMP por animal y día se vio negativamente afectado por la inclusión de torta de aceituna obteniendo un mayor BMP con estos subproductos. En cuanto a los ensayos de rendimientos productivos, la PDOC y la DOP pueden incluirse en la dieta hasta 120 y 240 g/kg respectivamente, sin efectos negativos en el caso de la PDOC y efectos menores para la DOP sobre los rendimientos productivos, la composición corporal y la calidad de la canal. La inclusión de PDOC y DOP no afectó a los recuentos microbianos ni al volumen, la composición y la emisión global de gases de los purines. Además, se observaron efectos beneficiosos sobre la grasa subcutánea con la inclusión de PDOC, mejorando su concentración en ácido oleico. La co-digestión anaerobia de subproductos agrícolas y purines mejora el BMP de la mezcla de sustratos en comparación con la digestión única de purines. Se obtuvieron mayores valores de BMP con la adición de los sustratos agrícolas, lo que confirma el mejor rendimiento de los sistemas en co-digestión a niveles de inclusión adecuados. Las combinaciones con tomate, pimiento y melocotón al nivel de inclusión 3 (50% de SV) alcanzaron el mayor BMP. Esto supuso un incremento del BMP del 41% con tomate, 44% con pimiento, 28% con melocotón y 12% con caqui. Los sustratos vegetales mostraron un mayor contenido en lípidos, prote, [CAT Actualment, la sostenibilitat del sector porcí depèn de la seua capacitat per a respondre a l'elevada demanda de productes ramaders derivada del creixement de la població, adaptant-se als canvis en els contextos econòmic i polític, i millorant el seu rendiment mediambiental mitjançant la mitigació del seu impacte ambiental. En aquest context, l'ús de subproductes agroindustrials ofereix matèries primeres alternatives en producció animal, amb una menor càrrega ambiental associada, en forma de pinsos per al bestiar, font de compostos bioactius o matèries primeres útils en la producció de bioenergia. Aquesta tesi doctoral pretén avaluar l'ús de subproductes agroindustrials mediterranis com a ingredients en pinsos per al bestiar porcí o com co-substrats per a la producció de biogàs. Amb aquest objectiu, es van dissenyar i realitzar quatre assajos per a avaluar l'ús de subproductes de la indústria de l'oli d'oliva i del suc de taronja en alimentació porcina, avaluant el seu valor nutricional i les conseqüències de la seua inclusió sobre el rendiment i la salut dels animals, la qualitat del producte final i les emissions de gasos dels purins. A més, es va realitzar un assaig per a avaluar l'efecte de quatre substrats agrícoles sobre el potencial bioquímic de metà (BMP) en co-digestió anaeròbia amb purins. Els resultats obtinguts a partir dels assajos de valor nutricional indiquen que les trotes d'oliva i les polpes de taronja assajades poden ser incloses en la dieta amb canvis associats en l'excreció de nutrients que condueixen a modificacions en les emissions potencials d'amoníac i BMP dels purins. Quant als subproductes de la torta d'oliva, l'assaig de valor nutricional amb tortes d'oliva crues (COC) i parcialment desengreixades (PDOC) va mostrar que totes dues coques són fonts apreciables de fibra insoluble, però tenen un valor energètic limitat (11.2 i 7.4 MJ/kg MS per a COC i PDOC respectivament) i un baix valor com a font de proteïnes. En canvi, les polpes de taronja deshidratades (DOP) i ensitjada assecada al sol (ESDOP) assajades són una font d'energia rellevant (14.2 i 13.2 MJ/kg MS per a DOP i ESDOP respectivament) amb valor afegit a causa del seu contingut en fibra soluble. Pel que fa als assajos d'emissions in vitro, els subproductes assajats van generar una disminució en l'excreció de N en l'orina i, en el cas de la polpa d'oliva, un augment de l'excreció de matèria seca en femtes. L'emissió d'amoníac per kg de purí va disminuir amb la inclusió de torta d'oliva i polpa de taronja, mentre que el BMP per animal i dia es va veure negativament afectat per la inclusió de torta d'oliva obtenint un major BMP amb aquests subproductes. Quant als assajos de rendiments productius, la PDOC i la DOP poden incloure's en la dieta fins a 120 i 240 g/kg respectivament, sense efectes negatius en el cas de la PDOC i efectes menors per a la DOP sobre els rendiments productius, la composició corporal i la qualitat de la canal. La inclusió de PDOC i DOP no va afectar els recomptes microbians ni al volum, la composició i l'emissió global de gasos dels purins. A més, es van observar efectes beneficiosos sobre el greix subcutani amb la inclusió de PDOC, millorant la seua concentració en àcid oleic. La co-digestió anaeròbia de subproductes agrícoles i purins millora el BMP de la mescla de substrats en comparació amb la digestió única de purins. Es van obtenir majors valors de BMP amb l'addició dels substrats agrícoles, la qual cosa confirma el millor rendiment dels sistemes en co-digestió a nivells d'inclusió adequats. Les combinacions amb tomaca, pimentó i bresquilla al nivell d'inclusió 3 (50% de SV) van aconseguir el major BMP. Això va suposar un increment del BMP del 41% amb tomaca, 44% amb pimentó, 28% amb bresquilla i 12% amb caqui. Els substrats vegetals van mostrar un major contingut en lípids, proteïnes, lignina i cel·lulosa que els substrats de fruita., [EN] Nowadays the sustainability of the pig sector relies on its capability to respond to the increasing demands for livestock products that are arising from population growth, adapting to changes in the economic and policy contexts, and improving its environmental performance through the mitigation of its impact on climate. In this framework, the use of the agro-industrial by-products offers potential alternative raw materials for animal production with a lower associated environmental burden in the form of feedstuffs for livestock, source of bioactive compounds or raw materials useful in bioenergy production. This PhD thesis aims to evaluate the use of Mediterranean agro-industrial by-products as feed ingredients for pigs or co-substrates for biogas production. To fulfil these objectives, four trials were designed and conducted to evaluate the use of olive oil and orange juice industry by-products in swine nutrition, assessing its nutritional value and the consequences of its inclusion in the diet on animals' performance and health, final product quality traits and gas emissions associated to the pig slurry. Additionally, one more trial was conducted to evaluate the effect of four agricultural substrates (tomato, pepper, peach and kaki) on the biochemical methane potential (BMP) in anaerobic co-digestion with pig slurry, focusing on the type of substrate and its inclusion level on the final substrate's mixture. The results presented in this PhD Thesis from the nutritional value assays indicate that the olive cakes and orange pulps tested can be potentially included in pig diets with associated changes in urine and faeces nutrients excretion that leads to modifications in the potential ammonia and BMP emissions from slurries. Concerning olive cake by-products, the nutritional value assay designed to test the crude (COC) and partially defatted (PDOC) olive cakes showed that they are appreciable sources of insoluble fibre but have limited energy value (11.2 and 7.4 MJ/kg DM for COC and PDOC respectively) and a low value as protein source. On the contrary, the dehydrated (DOP) and ensiled sun-dried (ESDOP) orange pulps tested are a relevant energy source (14.2 and 13.2 MJ/kg DM for DOP and ESDOP respectively) with added value in terms of SF concentration. With respect to the in vitro potential ammonia and BMP emissions assays, the by-products tested led to a decreased N excretion in urine and, in the case of the OC, increased DM excretion in faeces. The ammonia emission per kg of slurry decreased with the inclusion of olive cake and orange pulp, whereas the BMP per animal and per day was negatively affected by the inclusion of olive cake obtaining higher BMP with these by-products. Regarding the performance assays, the PDOC and the DOP may be included in balanced pig diets at rates of up to 120 and 240 g/kg respectively, without negative effects in the case of PDOC and minor effects for DOC on growth performance, body composition and carcass quality traits. Contrary to what was expected, the inclusion of PDOC and DOP did not affect microbial counts nor excreta volume, composition and global gas emission from the slurry. Additionally, beneficial effects on subcutaneous fat were observed with the inclusion of PDOC, improving its oleic acid concentration. The anaerobic co-digestion of agricultural by-products and pig slurry improves the BMP from the mixture compared to only pig slurry anaerobic digestion. Higher BMP values were obtained with increasing addition of agricultural substrate, confirming the better performance of co-digestion systems at adequate inclusion levels. In fact, combinations with tomato, pepper and peach at inclusion level 3 (50% of VS) achieved the highest BMP. This resulted in an increase in BMP of 41% with tomato, 44% with pepper, 28% with peach and 12% with kaki. Vegetable substrates (pepper and tomato) showed higher lipid, protein, lignin and cellulose content than fruit substrates (kaki and peach).

Capsicum oleoresin has recognized effects on digestion and fat metabolism. A total of 100 PIC x Danbred female pigs were divided in two experimental groups (10 pens/group) from 60Kg body weight (BW) to slaughter: one control group (T1) and another group (T2) where the sensorial additive (350ppm) was added from 90Kg to 130Kg BW. The study was carried out in Mediterranean summer conditions. Experimental rooms turned off their cooling systems at 90Kg BW to the end of the study. Temperature and humidity were recorded using dataloggers (HOBO®). Pig BW and intake were recorded before exposure to the additive and at the end of the administration of experimental feeds. Additionally, backfat thickness (BF) and loin depth (LD) were measured. Respiration rate (RR) and rectal temperature (RT) were also recorded at 0800, 1100, 1400 and 1700h. Carcass and meat quality parameters were measured in the slaughterhouse. Data was analyzed using Proc GLM (performance, carcass and meat quality) and Proc MIXED of repeated measures (RR, RT) of SAS. Environmental data confirmed heat stress conditions for finishing pigs (THI >71 from 0800 to 2200h). Growth performance, BF and LD did not differ between groups. Animals from T2 showed higher (P< 0.05) RR and lower (P< 0.05) RT compared to T1 at 17:00h. At slaughter, animals from T2 tended (P< 0.10) to have a higher fat content (3-4th rib level and ham) compared to T1. Ham pH at 25min and at 20h post-mortem, and drip losses at 48h post-mortem were lower (P< 0.05) in T2 group vs. T1. Concerning the fatty acid profile, the T2 showed a greater concentration of C18:1 and C20:1 compared to T1. In conclusion, the addition of the sensorial additive at the end of the growing period changed carcass composition and quality traits under heat stress conditions.

El proceso de secado convencional (gases calientes) del alperujo consume elevadas cantidades de energía fósil y afecta negativamente al coste del orujo graso y a la huella medioambiental de su posible uso en piensos. Nuevos procesos de secado con vapor de agua sobrecalentado están siendo evaluados por la industria, por ser más eficientes energéticamente, reducir la oxidación y no emitir partículas al aire (Sehrawat et al., 2016). El objetivo de este trabajo es estudiar el efecto de tres tipos de secado (convencional, vapor sobrecalentado y aire seco a altas temperaturas) del alperujo sobre la composición y digestibilidad in vitro del orujo graso para ganado porcino.

[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 investigated in both trials. The digestibility of MCP ranged from 75.2 to 87.4% and from 80.5 to 86.6% for DCP amongst methodologies, but differences between total tract and preceal methodologies were not statistically significant. 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 3 tested commercial sources of DCP was 80.1% (DCP1), 77.4% (DCP2) and 71.4% (DCP3); p > 0.05., This study has been developed under the project entitled Effect of the source of phosphorus on the apparent phosphorus digestibility coefficient and bone mineralization in broilers funded by Global Feed S.L.U.

[EN] Utilization of local by-products in pig nutrition can reduce the environmental impact of feeds and contribute to the sustainable development of the livestock sector. Orange pulp (OP) is the most abundant citrus by-product worldwide, but its seasonal production and perishable nature requires storage and drying procedures that might affect its nutritive value. Conservation process by fuel drying is expensive and can impair feed sustainability. Instead, in the Mediterranean countries, OP is sun-dried in the open-air. This procedure often implies a previous silage (during storage) which occurs naturally, because OP has a high level of sugars available for fermentation. Orange pulp is also rich in soluble fiber, which is highly fermentable at the pig's caecum and may reduce gas emissions from slurry. In this study, the nutritive value of conventional fuel-dehydrated (DOP) or ensiled-sun dried (ESDOP) was determined for pig diets. Sugars fermentation during ensiling increases fiber level in ESDOP and decreases energy digestibility compared to DOP, but both OP have an appreciable digestible energy content for pigs, around 87 and 94% that of barley, respectively. In addition, they do not differ in the amount of slurry excreted and contribute to reduce potential derived ammonia and methane emissions. The inclusion of orange pulp (OP) in pig diets may promote the circular economy, but drying procedures might influence its nutritional value and environmental impact. The purpose of this study was to determine the energy value and nutrient digestibility of dehydrated (DOP) and ensiled sun dried (ESDOP) orange pulp. The potential ammonia (NH3) and methane (CH4) emissions derived from slurry were also measured. Digestible energies of 14.2 and 13.2 MJ/kg DM for DOP and ESDOP, respectively, were estimated by difference after a 500 g/kg substitution of a basal diet with OPs. A high fiber digestion efficiency was observed for both OPs. Pigs fed the basal diet showed a higher intake and a greater excretion of urine N than pigs fed with OP, but fecal N excretion did not differ among diets. A higher benzoic and hippuric acid content in urine was observed in OP than in basal diet. Altogether, these findings explained a lower pH in slurry of OP diets and a reduction of potential NH3 emissions. The biochemical CH4 potential also decreased, especially with ESDOP. Overall, both OP are relevant sources of energy for pig diets. Their inclusion in feeds generate favorable changes of slurry characteristics that reduce potential NH3 and CH4 emissions., This work was supported by the Spanish Ministry of Science, Innovation and Universities (AGL2014-56653 and RTI2018-095246).

Para ajustar las dietas a las necesidades de los animales es necesario conocer el valor nutritivo de los alimentos a través del coeficiente de digestibilidad. La digestibilidad de la proteína bruta (PB) se determina a nivel ileal, generalmente con experimentos in vivo, que implican un elevado coste económico y de tiempo, así como la utilización de animales. El objetivo de este trabajo fue validar una metodología para la caracterización proteica de materias primas y subproductos para la fabricación de piensos, alternativa a la determinación in vivo para ganado porcino.

El alperujo es un subproducto reciente en las almazaras tradicionales, por la transformación de los procesos de molturación de 3 fases (aceite, alpechín y orujo) a sistemas de 2 fases (aceite y alperujo), debido a la nueva regulación medioambiental. Presenta una humedad del 65% y hasta un 15% (en materia seca, MS) de aceite. A día de hoy, se producen alrededor de 80.000 toneladas anuales en la Comunidad Valenciana, que son retiradas por orujeras. Su uso directo en la alimentación de la ganadería cercana a la zona de producción es una vía alternativa de aprovechamiento que, además, potencia la economía circular local. El objetivo del trabajo es determinar la digestibilidad in vitro de la MS (DIVMS) del alperujo para ganado bovino. Este trabajo se enmarca en un Proyecto mayor cuyo objetivo es desarrollar un modelo de gestión y aprovechamiento del alperujo en el norte de la Comunidad Valenciana para alimentación de ganado vacuno extensivo.

[ES] La alimentación animal es un factor clave para garantizar la sostenibilidad de la ganadería, especialmente en la producción intensiva de monogástricos. El impacto ambiental de este sector está principalmente relacionado con la producción de materias primas para piensos y la gestión de deyecciones. Las materias primas que conforman un pienso determinan su huella ambiental. En nuestras condiciones, la sustitución de soja por fuentes proteicas locales y un aumento en el uso de subproductos podrían, inicialmente, mejorar la sostenibilidad de los piensos. Sin embargo, para valorar las ventajas ambientales reales es necesario disponer de información precisa sobre el origen y los efectos en la digestibilidad de los nutrientes y la productividad de estas materias primas. Por otro lado, existe una relación directa entre la alimentación, excreción de nutrientes y emisión de gases a partir de las excretas en porcino y aves. La reducción de proteína de los piensos reduce las emisiones de amoniaco de las excretas. Para otros nutrientes como la fibra y la grasa, esta relación es más compleja. La implementación de estrategias basadas en la nutrición de precisión, el uso de tecnología (pretratamientos y enzimas) para aumentar la digestibilidad de las materias primas o el control de la salud intestinal de los animales es fundamental para aumentar la eficiencia en el uso de recursos y reducir el impacto ambiental de la ganadería. Este trabajo describe el estado del arte de la formulación de piensos sostenibles y la mejora en el aprovechamiento de nutrientes., [EN] Animal nutrition is a key factor in guaranteeing the sustainability of livestock farming, especially in the intensive production of monogastrics. The environmental impact of this sector is mainly related to the production of feedstuffs and manure management. Feed ingredients determine the environmental footprint of feeds. Under our conditions, soy replacement with local protein sources and an increase in the use of by-products could, initially, improve the sustainability of feeds. However, in order to assess the real environmental benefits of these strategies, it is necessary to have accurate information about the origin and the effects on nutrient digestibility and productivity of these ingredients. On the other hand, there exists a direct relationship between feeding, nutrient excretion and gas emission from excreta in pigs and poultry. Reducing protein in feed reduces ammonia emission from excreta. However, for other nutrients like fiber and fat, this relationship is more complex. The implementation of strategies based on precision nutrition, the use of technology (pre-treatments and enzymes) to increase the digestibility of feedstuffs or the control of gut health is essential to increase the efficiency in the use of resources and reduce the environmental impact of livestock. This work describes the state of the art in the formulation of sustainable feeds and the improvement in the use of nutrients

[EN] One of the key factors to improve swine production sustainability is the use of agro-industrial by-products in feeds, such as olive by-products. However, it is necessary to assess its effects on the overall production process, including the animal and the environment. With this aim, an experiment was conducted to determine the effects of including a partially defatted olive cake (PDOC) in pig diets on growth performance, faecal microbiota, carcass quality and gas emission from the slurry. Two finishing diets were formulated, a control (C) diet and a diet with PDOC included at 120 g/kg. Eighty finishing male pigs Duroc-Danbred x (Landrace x Large White) of 60.4 +/- 7.00 kg BW were divided between these two treatments. During the finishing period (60 to 110 kg BW, 55 days) average daily gain, average daily feed intake and feed conversion ratio were recorded. Faecal samples from the rectum of 16 animals per treatment were incubated for bacteria enumeration. At the end of finishing period, backfat thickness and loin depth (LD) were measured. Animals were slaughtered to obtain carcass weight and carcass composition parameters, and subcutaneous fat was sampled to analyse the fatty acid (FA) profile. In addition greenhouse gas and ammonia emissions were measured during pig slurry storage using the methodology of dynamic flux chambers. An initial slurry characterisation and biochemical methane potential (B-0) were also determined. No significant differences between treatments were found in performance, carcass quality and microbial counts with the exception of LD, which was lower in PDOC compared with C animals (45.5 v. 47.5 mm, SEM: 0.62; P = 0.020). The FA profile of the subcutaneous fat did not differ between treatments, but the monounsaturated FA (MUFA) concentration was higher and the polyunsaturated FA was lower in the animals fed PDOC (50.9 v. 48.3, SEM: 0.48, P < 0.001; 17.6 v. 19.3, SEM: 0.30, P < 0.001 in mg/100 g of Total FA, for PDOC and C animals, respectively). The initial pig slurry characterisation only showed differences in ADF concentration that was higher (P < 0.05) in the slurry from PDOC treatment. Regarding gas emission, slurries from both treatments emitted similar amounts of ammonia (NH3), carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), as well as B-0 values. The results obtained suggest that PDOC may be included in balanced pig diets at rates of up to 120 g/kg without negative effects on performance, carcass quality, gut microflora and slurry gas emission, while improving the MUFA concentration of subcutaneous fat., This project was funded by the Spanish Ministry of Science and Innovation (AGL2014-56653). Preliminary results from this work have been published in an abstract form (Ferrer et al., 2017). Acknowledgements are also expressed to DCOOP for providing PDCO.

A total of 192 laying hens were used to evaluate the effect of dietary mineral content and phytase dose on nutrient utilization, egg production and quality and bone mineralization of young laying hens. Four dietary treatments were studied: PC, positive control with no added phytase, 4.07% Ca and 0.61% P, NC, negative control with no added phytase, 2.97% Ca and 0.37% P, and P500 and P1000, where NC diet was supplemented with phytase at 500 and 1000 FTU/kg, respectively. Hens’ performance and egg traits were controlled from 22 to 31 weeks of age. Coefficients of total tract apparent digestibility (CTTAD) of nutrients were determined at 25 and 31 weeks of age. Apparent ileal digestibility (AID) and blood content of Ca and P, as well as bone traits, were determined at 31 weeks of age. Ca and P retention was higher in birds on PC diet at 25 weeks, but not at 31 weeks of age compared to those on NC diet (p &lt, 0.05). P1000 birds had the highest CTTAD values for dry and organic matter at both ages (p &lt, 0.001). CTTAD of Ca was significantly higher in P1000 diet than in NC diet at 31 weeks of age (p &lt, 0.001). Birds fed with P500 diet at 25 weeks of age and P1000 at 31 weeks of age showed higher CTTAD and retention of P, but lower excretion of P than those fed NC diet (p &lt, 0.05). Phytase inclusion linearly increased AID of dry matter and P (p &lt, 0.001). P500 hens fed had the greatest body weight at the end of the trial (p &lt, 0.05) and P1000 birds had the best feed conversion ratio (p &lt, 0.05). Fowl fed a PC diet produced eggs with higher shell thickness and yolk color than those fed on NC diet (p &lt, 0.05). Phytase inclusion linearly increased the yolk color (p &lt, 0.05). Tibia of laying hens fed with PC had significantly higher ash content than those on NC diet (p &lt, 0.05), and birds fed with P1000 presented intermediate values. It can be concluded that it would be advisable to increase the dose of phytase in the feed of laying hens to obtain long-term benefits.

Twenty-five genetic groups were produced following a diallel-crossbreeding scheme among five lines: three dam and two sire lines belonging to two Spanish Research Institutions (UPV and IRTA). A total of 2773 young rabbits from 525 kindlings were controlled in different seasons. Growth traits were evaluated during the fattening period lasting from five to nine weeks. On average, genetic groups coming from lines selected for growth rate were heavier (+57 g at weaning and 311 g at 60 days), had a faster growth rate (+9g/d) and a realised higher daily feed intake (+12.9 g/d), improving feed conversion ratio (-0.21), than the groups originated from crosses among lines selected for litter size. Crossbreeding parameters were estimated using the Dickerson model. Maternal genetic and heterosis effects were close to 0 or very low. Direct genetic effects mainly regulated expression of these traits.