Influencia del aporte proteico y energético durante la gestación sobre la eficiencia reproductiva de la cerda ibérica, y del manejo nutricional del lechón ibérico lactante sobre su crecimiento y adaptación al destete

La presente Tesis Doctoral se ha planteado con el objetivo general de elevar la eficiencia reproductiva de la cerda Ibérica -entendida en términos de productividad numérica, es decir, del número de lechones destetados por cerda y año- a través del manejo nutricional, tanto del lechón en la fase previa al destete como de la propia cerda en la etapa final de la gestación, fase en la que la demanda de nutrientes en soporte de crecimiento de fetos y tejidos reproductivos alcanza su máximo, y al propio tiempo, su nivel de ingestión tiene gran influencia sobre la subsiguiente lactación. Las singulares características fisiológicas y metabólicas de la raza porcina Ibérica –y, en su caso, las particularidades del sistema productivo- desaconsejan la extrapolación directa de recomendaciones nutricionales basadas en observaciones obtenidas en razas convencionales o mejoradas. Los ensayos que esta Tesis Doctoral comprende se han realizado con los siguientes objetivos específicos: 1. Determinar en el lechón Ibérico el efecto de la lactancia intermitente, aplicada durante la última semana de una lactancia de 35 días, sobre el consumo de alimento sólido previamente al destete y tras el destete y los correspondientes parámetros productivos. 2. Determinar su efecto sobre la digestibilidad de nutrientes en una dieta de iniciación ofrecida al lechón en el periodo inmediato a su destete. 3. Determinar en cerdas Ibéricas en el tercio final de la gestación los efectos del plano de alimentación y del contenido en proteína, de composición aminoacídica equilibrada, sobre la ganancia y movilización de reservas, juzgadas mediante los cambios ponderales registrados en gestación y lactación, respectivamente; determinar sus efectos sobre la eficiencia reproductiva de las cerdas, a través del registro del número total de lechones nacidos, nacidos..

Ciencias de la Biología y Agronomía

Este volumen I contiene 17 capítulos arbitrados que se ocupan de estos asuntos en Tópicos Selectos de Ciencias de la Biología y Agronomía, elegidos de entre las contribuciones, reunimos algunos investigadores y estudiantes. Se presenta un Estudio Comparativo de los Recursos Hidrológico-Forestales de la Microcuenca de la Laguna de Epatlan, Pue. (1993 a 2014); la Situación Actual de la Mancha de Asfalto en Maíz (Zea mays L.) en los Municipios de Jiquipilas y Ocozocoautla, Chiapas, México; las poblaciones sobresalientes de maíz de la raza Zapalote Chico, en la Región Istmeña de Oaxaca; Se indica el índice de área foliar de cultivo de Chile Poblano mediante dos métodos en condiciones protegidas; Esquivel, Urzúa y Ramírez exploran el efecto de la biofertilización con Azospirillum en el crecimiento y producción de Jitomate; esbozan su artículo sobre la determinación del nivel de Heterosis en híbridos de Maíz para la Comarca Lagunera; una investigación sobre la estabilización de semilla de Solanum lycopersicum durante el almacenamiento y estimulación de la germinación; acotan sobre el CTAB como una nueva opción para la detección de Huanglongbing en cítricos, plantean su evaluación sobre el aluminio y cómo afecta la vida de florero de Heliconia psittacorum; indican sobre el impacto del H-564C, como un híbrido de maíz con alta calidad de proteina para el trópico húmedo de México; presetan su investigación sobre la producción de Piña Cayena Lisa y MD2 (Ananas comosus L.) en condiciones de Loma Bonita, en Oaxaca; acotan sobre el efecto de coberteras como control biológico por conservación contra áfidos en Nogal Pecanero; esbozan sobre la caracterización de cuatro genotipos de Frijol Negro en Martínez de la Torre, Veracruz, México; presentan una caracterización hidroecológica de la microcuenca de Arroyo Prieto, Yuriría, Gto., y alternativas para su restauración ambiental; presentan su investigación sobre el efecto del hongo Beauveria bassiana sobre solubilización de fosfatos y la disponibilidad de fósforo en el suelo; plantean su investigación sobre la Germinación y regeneración in vitro de Epidendrum falcatum LINDL; esbozan su artículo sobre genotipos de frijol negro y su tolerancia a sequía terminal en Veracruz, México

Effect of increasing lysine supply during last third of gestation on reproductive performance of Iberian sows

Ninety purebred Iberian (IB) sows in second or third parity were used to determine the effects of dietary lysine (Lys) concentration during last third of pregnancy on sow and litter performance. The sows were randomly assigned to one of three dietary treatments: 5.5 (LLys, Control), 7.4 (MLys) and 8.7 (HLys) g Lys kg-1 diet. Feed allowance was 2.30-2.33 kg d-1. Close to farrowing a conventional lactation diet was used. Dietary Lys did not affect body-weight (BW) gain in late gestation of second-parity sows. However, in third-parity sows, a strong tendency was observed for BW gain to increase during late pregnancy with dietary Lys levels higher than 5.5 g kg-1 (p=0.061). Body-weight losses during lactation were never influenced by Lys supply. A strong tendency (p=0.064) for a lower ratio between piglets born alive and total piglets born was observed in second-parity sows fed the Control gestation diet. Litters and piglets from sows on this diet had the lowest weight at birth (p0.05). In conclusion, under moderate energy supply, adequate reserves for subsequent lactation can be achieved in second- and third-parity IB sows with a daily provision of at least 17.2 g lysine over the last third of pregnancy, what implies a substantial increase in protein supply respect to traditional practices

Design of a low-density SNP panel for intramuscular fat content and fatty acid composition of backfat in free-range Iberian pigs

Intramuscular fat (IMF) content and fatty acids (FA) profile determine important sensory and technological characteristics of the meat, being interesting traits to be included in breeding programs for Iberian pig. In a previous study, we analyzed the longissimus dorsi transcriptome of Iberian pigs with divergent breeding values for IMF identifying 63 and 12 functional candidate genes and long non-coding RNA being differentially expressed. The first objective of this work was to use the RNA-seq data generated in that study in order to design a low-density panel with 50 single-nucleotide polymorphisms (SNP). The second aim was to evaluate the effects of this SNP panel on IMF content and backfat FA profile in a closed commercial population of Iberian pigs. The IMF content and backfat FA composition were determined in 940 Iberian pigs. A total of 837 SNPs were identified in the selection of genes and lncRNA. Out of the 50 selected SNP, 11 were monomorphic in the population and 2 failed in their genotyping. Association analyses were carried out for the 37 SNP segregating in the population (minor allele frequency, MAF > 0.05). Regarding IMF content, a significant additive effect (q-value  G SNP, in which the G allele was linked to an increase of 7.59% (additive effect expressed as a percentage of the mean of the trait). For the backfat FA composition, we observed 24 SNP with significant associations. The strongest effects were detected for the ELOVL6:g.112186423A > G and FASN_rs331694510G > A SNP. The A allele of both SNPs were associated to a lower percentage of palmitic (C16:0) and palmitoleic (C16:1) acids and an increase in oleic acid (C18:1). In addition, the AMPD3:g.49043886C > G SNP had significant effects on C16:0, stearic (C18:0), C18:1 and on the sum of saturated and monounsaturated fatty acids. Finally, significant effects of the EGR2:66286345G > T SNP on C18:0 and C18:1 and other minor FA were observed. Our findings reveal ADIPOQ:g.124646194T > G, ELOVL6:g.112186423A > G, and FASN_rs331694510G > A may be useful in breeding programs for Iberian pigs including FA profile and IMF content as selection goals, provided that their potential effects on other traits of interest are controlled.This work was funded by contracts (CON15-078, CON17-125, CON19-281) between the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria and the company Sánchez Romero Carvajal Jabugo SA., in addition to the IDI-20171141 grant from the Centro para el Desarrollo Tecnológico Industrial (CDTI). RPeer reviewe

Feed efficiency and loin meat quality in Iberian pigs

We investigated the ability to predict production performance in Iberian pigs in an extensive production system from measurements of feed efficiency measured intensively. The second objective of this work was to study the relationship between feed efficiency and meat quality (composition, juiciness, tenderness, color, and subcutaneous fatty acid composition) and if cooked and cured quality properties can be predicted by properties in fresh meat. Thirty Iberian sows received successively a restricted diet of concentrate (P1concentrate) and acorns (P2acorn) intensively and an ad libitum diet of acorns supplemented with a restricted amount of concentrate (P3montanera) extensively. Pigs that were more feed efficient on concentrate were less feed efficient on acorns and had higher body weight gain during the montanera. Improved feed efficiency on acorns reduced the concentration of α-linolenic and linoleic fatty acid composition of subcutaneous fat. Faster body weight gain in montanera resulted in a desirable reduction in cooking loss and a reduction in palmitic acid content in subcutaneous fat, and a potentially undesirable reduction in meat redness. Tenderness in cooked or cured loin was not significantly related to tenderness in the raw product. Cooking loss was positively related to purge and centrifugal drip loss and to color coordinates a*24 and b*24 in raw samples. We conclude that feed efficiency and body weight gain may be improved in the traditional Iberian production system, with a positive effect on cooking loss but potentially resulting in paler mea

Genetic parameter estimation and gene association analyses for meat quality traits in open‐air free‐range Iberian pigs

Meat quality of Iberian pigs is defined by the combination of their genetic characteristics and the particular production system. To carry out a genetic analysis of the main meat quality traits, we estimated their heritabilities, genetic correlations and the association effects of 32 selected SNPs of 12 candidate genes. A total of ten traits were measured in longissimus dorsi samples from 1,199 Iberian pigs fattened in the traditional free-range system: water holding capacity (thawing, cooking and centrifuge force water losses), instrumental colour (lightness L*, redness a* and yellowness b*), myoglobin content, shear force on cooked meat, and shear force and maximum compression force on dry-cured loin. Estimated heritability values were low to moderate (0.01 to 0.43) being the lowest for L* and the highest for cooking loss. Strong genetic correlations between water holding capacity traits (0.93 to 0.96) and between myoglobin content and a* (0.94) were observed. The association analyses revealed 19 SNPs significantly associated with different traits. Consistent and strong effects were observed between PRKAG3 SNPs (rs319678464G > C and rs330427832C > T), MYH3_rs81437544T > C, CASP3_rs319658214G > T and CTSL_rs332171512A > G and water losses. Also for CAPN1_rs81358667G > A and CASP3_rs319658214G > T and shear force. The SNPs mapping on PRKAG3 showed the highest effects on Minolta colour traits. Genotyping of these SNPs could be useful for the selection of Iberian young boars with similar estimated breeding values for productive traits.This work was financially supported by CON15-078, CON17-125 (INIA-SRC) and IDI-20171141 (CDTI) grants. Miguel Ángel Fernández-Barroso was funded by a FPI Ph.D. grant from the INIA institution. We want to thank to Sánchez Romero Carvajal (SRC) enterprise for the technical support, especially to its manager Jose María Pariente.Peer reviewe