Revista Mexicana de Ciencias Pecuarias (E-Journal)
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Comportamiento productivo y valor nutricional de veza común (Vicia sativa l.) durante otoño-invierno en Zacatecas, México
Get PDFEl momento óptimo de cosecha y la calidad nutricional esperada de forraje de veza común permitiría mejorar su uso en los sistemas de producción. El objetivo fue determinar la producción de forraje, contenido de proteína cruda y los componentes de rendimiento en seis fechas de corte de veza común durante el ciclo otoño-invierno de riego en Zacatecas. El experimento se sembró el 9 de diciembre del 2016 bajo un diseño experimental completamente al azar con cuatro repeticiones. La cosecha de las plantas se realizó cada 14 días, iniciando a los 47 después de la siembra. Las variables medidas fueron: rendimiento de forraje verde y seco, producción de hoja verde y senescente, tallo, flor, vaina y proteína cruda. Los datos se analizaron con medidas repetidas mediante el paquete estadístico SAS. En el forraje verde se observó un incremento (P<0.05) desde el día 47 con 493 kg ha-1 hasta el día 103 con 20,562 kg ha-1. El forraje seco mostró un incremento constante (P<0.05) desde el día 47 con 14 kg MS ha-1 hasta llegar al 103, con 3,796 kg MS ha-1. En proteína cruda se observa un decremento después del día 60 (P<0.05) y se mantiene similar desde el día 75 hasta el 103 con valores desde 27 hasta 29 % base seca. La acumulación más baja fue al 117 con 20.7 %, diferente a los días anteriores (P<0.05). Se concluye que la fecha óptima para el uso en la alimentación del ganado sería alrededor del día 100, al inicio de la floración
In vitro ruminal degradation of carbohydrate fractions in tropical grasses fertilized with nitrogen
Get PDFThe goal was to determine the digestion rates of carbohydrate fractions A (sugars, oligosaccharides and organic acids), B1 (starch and soluble fiber), NSC (non-structural carbohydrates) and B2 (available NDF) in four tropical grasses using the gas production technique. Samples of whole forage (WF), residue insoluble in 90% ethanol (EIR) and isolated NDF (iNDF) were fermented in vitro and gas production measured. Gas volumes were determined from the following fractions, A = WF minus EIR; B1 = EIR - ND; NSC = WF - iNDF; and B2 = iNDF. Grasses were Andropogon gayanus, Urochloa brizantha, Cynodon plectostachyus, and Megathyrsus maximus each grown in Veracruz, Mexico on four plots (5×5 m), fertilized (relationship equivalent to 0 and 100 kg N/ha) and clipped 35 d after the N fertilization. A complete randomized block design with factorial arrangement 4×2 and two replicates per treatment was used. Factors were grass species and N fertilization. Data were fit using a single-pool exponential model with lag. The volume (mL gas/100 mg OM), rate (%/h) and lag (h) were: WF (22.8; 5.3; 2.1); A (3.2; 15.7; 0.5); B1 (1.5; 15.7; 0.2); and B2 (18.3; 6.6; 5.2). Andropogon and Urochloa had higher NSC content compared to Megathyrsus and Cynodon but lower gas yield per unit of NSC. Rates of digestion for the B2 fraction ranged from 4 to 8 %/h; and NSC digestion rate averaged 15.7 %/h. Nitrogen fertilization reduced carbohydrate pool sizes but did not affect rates of digestion. It is concluded that the rates of digestion of the carbohydrate fractions differs by grass specie.Our goal was to determine the digestion rates of carbohydrate fractions A (sugars, oligosaccharides and organic acids), B1 (starch and soluble fiber), NSC (non-structural carbohydrates) and B2 (available NDF) in four tropical grasses using the gas production technique. Samples of whole forage (WF), residue insoluble in 90% ethanol (EIR) and isolated NDF (ND) were fermented in vitro and gas production measured. Gas volumes determined from the following fractions, A = WF minus EIR; B1 = EIR - ND; NSC = WF - ND; and B2 = ND. Grasses were Andropogon gayanus, Urochloa brizantha, Cynodon plectostachyus, and Megathyrsus maximum each grown in Veracruz, Mexico on four plots (5×5 m), fertilized (relationship equivalent to 0 and 100 kg N/ha) and clipped 35 d after the N fertilization. A complete randomized block design with factorial arrangement 4×2 and two replicates per treatment was used. Factors were grass species and N fertilization. Data were fit using a single-pool exponential model with lag. The volume (mL gas/100 mg OM), rate (%/h) and lag (h) were: WF (22.8; 5.3; 2.1); A (3.2; 15.7; 0.5); B1 (1.5; 15.7; 0.2); and B2 (18.3; 6.6; 5.2). Andropogon and Urochloa had higher NSC content compared to Megathyrsus and Cynodon but lower gas yield per unit of NSC. Rates of digestion for the B2 fraction ranged from 4 to 8 %/h; and NSC digestion rate averaged 15.7 %/h. Nitrogen fertilization reduced carbohydrate pool sizes but did not affect rates of digestion. It is concluded that ruminally available energy from SC and NSC in tropical forages should be revised more extensively
Artemisia cina 30 CH homeopathic treatment against Haemonchus contortus
Get PDFThe anthelmintic resistance problem is widely recognized in sheep production. Therefore, new methods of control against gastrointestinal nematodes (GIN) need to be integrated. The aim of this work was to assess the toxicity of A. cina 30 CH as a homeopathic product against Haemonchus contortus in in vitro and in vivo assays. A. cina 30 CH was obtained from a commercial laboratory, and confirmation of artemisinin as a key ingredient was performed with mass spectrophotometry. The A. cina 30 CH and the artemisinin pure reagent were used for the inhibition of egg hatching (IEH) and for the inhibition of larval migration of H. contortus L3 (ILM). In addition, three groups of 10 naturally infected lambs with GIN were treated with A. cina 30 CH and albendazole, and 10 were used as control. The parasitic infection was monitored at 0, 7, 14 and 28 d postreatment (PT) to determine the number of eggs per gram (epg) and FAMACHA index. The in vitro data showed 100 % IEH and 64.7 % ILM by A. cina 30 CH, and nonlethal activity was observed with the artemisinin pure reagent. The toxicity of A. cina 30 CH against H. contortus in infected lambs was observed after 7 d of infection. Administration of the A. cina 30 CH yielded a 69 % reduction in the epg at 28 d PT, similar to the albendazole (P<0.05). In conclusion, A. cina 30 CH had the ability to IEH and ILM of H. contortus in in vitro assays and reduced the number of eggs of H. contortus, which is the primary parasitic nematode in grazing lambs, thereby reducing infection.The anthelmintic resistance problem is widely recognized in sheep production. Therefore, new methods of control against gastrointestinal nematodes (GIN) need to be integrated. The aim of this work was to assess the toxicity of A. cina 30 CH as a homeopathic product against Haemonchus contortus in in vitro and in vivo assays. A. cina 30 CH was obtained from a commercial laboratory, and confirmation of artemisinin as a key ingredient was performed with mass spectrophotometry. The A. cina 30 CH and the artemisinin pure reagent were used for the inhibition of egg hatching (IEH) and for the inhibition of larval migration of H. contortus L3 (ILM). In addition, three groups of 10 naturally infected lambs with GIN were treated with A. cina 30 CH and albendazole, and 10 were used as control. The parasitic infection was monitored at 0, 7, 14 and 28 d postreatment (PT) to determine the number of eggs per gram (epg) and FAMACHA index. The in vitro data showed 100 % IEH and 64.7 % ILM by A. cina 30 CH, and nonlethal activity was observed with the artemisinin pure reagent. The toxicity of A. cina 30 CH against H. contortus in infected lambs was observed after 7 d of infection. Administration of the A. cina 30 CH yielded a 69 % reduction in the epg at 28 d PT, similar to the albendazole (P<0.05). In conclusion, A. cina 30 CH had the ability to IEH and ILM of H. contortus in in vitro assays and reduced the number of eggs of H. contortus, which is the primary parasitic nematode in grazing lambs, thereby reducing infection
Efecto de la fecha de corte y del uso de aditivos en la composición química y calidad fermentativa de ensilado de girasol
Get PDFThe aim of this study was to evaluate cutting dates and the use of additives on the silage quality of the entire sunflower plant. The forage variety (Rumbosol-91) was harvested in weeks 1, 3 and 5 post-flowering (F1, F2 and F3, respectively) and treated with the following additives: 1) 1.5 × 105 cfu of g-1 forage inoculant, based on homofermentative lactic acid bacteria Enterococcus faecium, Pediococcus pentosaceus and Lactobacillus plantarum (INOC), 2) 3 ml kg-1 forage of an 85% formic acid solution (FORM) and 3) without additive (Control); following a 3x3 factorial design with five replications. Effluent production and total dry matter (DM losses decreased, from 282 and 134 g kg-1 on D + 1 to 96 and 87 g kg-1 on D + 5 as a result of the high moisture content of the forage close to flowering. NIRS analysis of the silage samples showed that the protein, fiber and digestibility contents decreased significantly with the maturity of the plant; the rapid accumulation of oil in the DM made the energy concentration higher in the most advanced phenological state. The fermentative quality of the silages was satisfactory, regardless of the cutting moment and the use of additive. It is concluded that the cutting moment of the plant is better at five weeks post-flowering, when an acceptable fermentation is expected without the need to use preservatives.El objetivo fue evaluar fechas de corte y del uso de aditivos sobre la calidad del ensilado de la planta entera de girasol. La variedad forrajera (Rumbosol-91) se cosechó en las semanas 1, 3 y 5 post-floración (F1, F2 y F3, respectivamente) y tratada con los siguientes aditivos: 1) 1.5 × 105 ufc de inoculante g-1 de forraje, a base de bacterias lácticas homofermentativas Enterococcus faecium, Pediococcus pentosaceus y Lactobacillus plantarum (INOC), 2) 3 ml kg-1 de forraje de una solución al 85% de ácido fórmico (FORM) y 3) sin aditivo (Testigo); siguiendo un diseño factorial 3x3 con cinco repeticiones. La producción de efluente y las pérdidas totales de materia seca (MS) se redujeron, desde 282 y 134 g kg-1 en F+1 hasta 96 y 87 g kg-1 en F+5 como resultado del alto contenido de humedad del forraje próxima a la floración. El análisis NIRS de las muestras de ensilaje mostró que los contenidos de proteína, fibra y digestibilidad descendían significativamente con la madurez de la planta; la rápida acumulación de aceite en la MS hizo que la concentración energética fuese superior en el estado fenológico más avanzado. La calidad fermentativa de los ensilajes fue satisfactoria, independientemente del momento de corte y del uso de aditivo. Se concluye que es preferible el corte de la planta a las cinco semanas post-floración, donde se espera una fermentación aceptable sin necesidad de conservantes
Frecuencia de contaminación y de serotipos de Salmonella enterica y Escherichia coli en una operación integrada de matanza y deshuese de bovinos
Get PDFThis study aimed to determine the frequency of contamination and serovar diversity of Salmonella enterica (SE) and Escherichia coli (EC) in different stages of cattle slaughtering and deboning processes. Fecal, carcass, and primal cut (100 of each type) samples were collected in a Federally Inspected slaughterhouse in Mexicali, Baja California. EC was not analyzed in fecal samples because it is part of the gut microbiota. Strain identity was confirmed by biochemical methods and PCR, using the taxonomic genes invA and gadA for SE and EC, respectively. In EC, the presence of genes associated with the main pathotypes was also investigated. SE had a 34 % frequency in fecal samples, 3% in carcasses, and 2% in cuts, while Montevideo was the predominant serovar (72.5 % of the total strains). EC was detected in carcasses (34 %) and cuts (11 %) at an average concentration of 0.012 and 0.33 log CFU cm-2, respectively. Although several of the identified EC serovars were associated with enterotoxigenic or Shiga toxin-producing strains, none carried the virulence factors typically observed in these pathotypes. In summary, beef carcasses and cuts are not a relevant source of EC pathogenic strains. However, beef is an important reservoir of SE, which represents a public health risk. Genomic studies are required on the virulence profile and genes of SE strains commonly associated with subclinical infections and isolated from apparently healthy animals.El objetivo fue determinar la frecuencia de contaminación y la diversidad de serotipos de Salmonella enterica (SE) y Escherichia coli (EC) en diferentes etapas de los procesos de matanza y deshuese de bovinos. Se tomaron muestras de heces, canales y cortes primarios (100 de cada tipo) en un rastro Tipo Inspección Federal ubicado en Mexicali, Baja California. EC no se analizó en heces, por ser esta bacteria parte de la microbiota intestinal. La identidad de las cepas se confirmó por métodos bioquímicos y por PCR: genes taxonómicos invA y gadA, para SE y EC, respectivamente. En EC se investigó también la presencia de genes asociados con los principales patotipos. SE tuvo una frecuencia de 34 % en heces, 3 % en canales y 2 % en cortes, siendo Montevideo el serotipo predominante (72.5 % del total de cepas). EC se detectó en canales (34 %) y en cortes (11 %), en concentraciones promedio de 0.012 y 0.33 log UFC cm-2, respectivamente. Aunque varios de los serotipos de EC identificados están asociados con cepas enterotoxigénicas o productoras de toxinas tipo Shiga, ninguno portaba factores de virulencia característicos de estos patotipos. En resumen, las canales y cortes de bovino no son una fuente relevante de cepas patógenas de EC. En contraste, los bovinos constituyen un importante reservorio de SE, lo cual representa un riesgo para la salud pública. Se requieren estudios genómicos sobre el perfil de virulencia y los genes asociados con infecciones subclínicas en cepas de SE provenientes de animales aparentemente sano
Origen metabólico y propiedades bioactivas de ácidos grasos ramificados e impares en leche de rumiantes. Revisión
Get PDFMilk odd and branched-chain fatty acids (OBCFA) are a group of lipids that represents less than 5 % of the total fatty acids (FA) and that includes a group of molecules, among which the most abundant are the isomers of the pentadecanoic (15:0, iso-15:0 and anteiso-15:0), hexadecanoic (iso-16:0), and heptadecanoic (17:0, iso-17:0 and anteiso-17:0) FA. OBCFA are synthesized by rumen microorganisms from the molecules produced during feed fermentation processes. Recent research indicates the possibility of endogenous synthesis of some odd (15:0 and 17:0) and branched-chain (iso-1:0 and anteiso-17:0) FA. The presence of these FA in milk is influenced by dietary factors, mainly the starch vs fiber proportion, forage to concentrate ratio, and the supplementation with fat sources that change the lipid metabolism, which modifies the OBCFA profile of milk. Milk and dairy products are the main and almost only source of OBCFA in the human diet. Despite their low concentration, OBCFA possess bioactive properties that have been shown in different investigations. This article reviews the metabolic origin, bioactive properties, and most recent nutritional strategies directed to manipulate the contents and profiles of OBCFA in milk fat.Los ácidos grasos de cadena impar y ramificada (AGCIR) son un grupo de lípidos en la leche que no supera el 5 % de los ácidos grasos (AG) totales, y que agrupa a un conjunto de moléculas entre las cuales los isómeros de los AG pentadecanoico (15:0, iso 15:0 y anteiso 15:0), hexadecanoico (iso 16:0) y heptadecanoico (17:0, iso 17:0 y anteiso 17:0) son los más abundantes. Los AGCIR son sintetizados por microorganismos ruminales a partir de moléculas producidas durante los procesos de la fermentación de alimentos. Investigaciones recientes señalan la posibilidad de síntesis endógena de algunos AG de cadena impar (15:0 y 17:0) y ramificada (iso 17:0 y anteiso 17:0). La presencia de estos AG en la leche está influenciada por factores dietéticos, principalmente con la proporción de almidón vs fibra, la relación forraje/concentrado y la suplementación con fuentes de grasa que generan cambios en el metabolismo lipídico, que inducen modificaciones en el perfil de AGCIR de la leche. La leche y los productos lácteos son la principal y casi única fuente de AGCIR de la dieta humana. A pesar de su baja concentración, los AGCIR representan propiedades bioactivas que han sido puestas de manifiesto en distintas investigaciones. Este trabajo revisa el origen metabólico, las propiedades bioactivas, así como las más recientes estrategias alimenticias dirigidas para manipular los contenidos y perfiles de AGCIR en la grasa láctea
Pasta de higuerilla desintoxicada en dietas para pollos de engorda
Get PDFCastor (Ricinus communis L.) meal contain highly toxic substances. Three detoxification methods were evaluated for their effectiveness and their inclusion in diets for broilers. Five treatments (experimental diets) were evaluated: control diet based on corn and soybean meal (SM), non-detoxified castor meal (NDC), autoclaved castor meal (AC), chemically treated castor meal (ChC) and autoclave and chemical methods treated castor meal (AChC). Each treatment was randomly assigned to seven experimental units with 10 chickens each. The variables evaluated were: feed consumption (FC), feed conversion ratio (FCR), weight gain (WG), carcass yield (CY), breast yield (BY), leg to thigh yield (LTY), digestive system development, walking ability (WA), valgus-varus angulation (VVA), and latency to lie down (LLD). Chickens fed NDC and ChC had lower FC and WG (P<0.05). However, there was no difference among treatments for CA. There were differences among treatment (P<0.05) for WA and VVA, but there were not for LLD (P>0.05). The results showed that autoclave treatment (1 atm, 121 oC for 60 min) decreased toxicity in castor meal, since birds in the AC treatment had a similar productive behavior (P>0.05) to those in the control diet.La pasta de higuerilla (Ricinus communis L) contiene sustancias altamente tóxicas, por lo que se evaluó la efectividad de tres métodos de desintoxicación y su inclusión en dietas para pollos de engorda. Se evaluaron cinco tratamientos (dietas experimentales): dieta testigo a base de maíz y pasta de soya (PS), pasta de higuerilla sin desintoxicar (PH), pasta de higuerilla tratada con autoclave (PHA), pasta de higuerilla tratada con el método químico (PHQ) y pasta de higuerilla tratada con autoclave y método químico (PHAQ). Cada tratamiento se asignó al azar a siete unidades experimentales con 10 pollos cada una. Las variables evaluadas fueron: consumo de alimento (COA), conversión alimenticia (CA), ganancia de peso (GP) rendimiento en canal (RC), rendimiento de pechuga (RP), rendimiento de pierna con muslo (RPM), desarrollo del sistema digestivo, habilidad para caminar (HC), angulación valgus /varus (AVV) y latencia a postrarse (LP). Los pollos alimentados con PH y PHMQ tuvieron menor COA y GP (P<0.05), sin embargo, no hubo diferencias entre tratamientos para CA. Se encontraron diferencias entre tratamiento (P<0.05) para HC y AVV, mientras que en LP no hubo diferencias (P>0.05). Los resultados evidencian que el tratamiento con autoclave (1 atmosfera de presión durante 60 min a 121 °C) disminuyó la toxicidad en la pasta de higuerilla, ya que las aves del tratamiento PHMA tuvieron un comportamiento productivo similar (P>0.05) a las de la dieta testigo