Pregnancy associated glyciprotein and progesterone concentrations in plasma of sheep during gestation and post-partum period

Contributed to: 109th meeting of the British Society of Animal Production (Scarborough, UK, Mar 21-23, 1994).Peer reviewe

Comparative study of rumen activity in churra and merino sheep

Contributed to: 107th Meeteing of the British Society of Animal Production (Scarborough, UK, March 15-17 (1993).Peer reviewe

Influence de l'administration directe d'enzymes fibrolytiques sur l'activité fibrolytique dans le rumen du mouton

6 pages, 3 tables.--Contributed to: 12th Seminar of the FAO-CIHEAM Sub-NetWork on Sheep and Goat Nutrition. "Nutritional and foraging ecology of sheep and goats"(Thessalonica, Grecia, Oct 11-13, 2007).Six rumen-fistulated Merino sheep were used in a crossover design experiment to evaluate the effects of a direct-fed exogenous fibrolytic enzyme (12 g/d; ENZ) on ruminal fermentation. The enzyme presented endoglucanase and xylanase activities. Sheep were fed a mixed grass hay:concentrate (70:30; fresh matter basis) diet at a daily rate of 60 g/kg body weight 0.75. Concentrations of NH3-N and volatile fatty acids (VFA) and enzymatic activities were determined in ruminal samples at 0, 4 and 8 h after feeding. Samples of the grass hay were incubated in situ in the rumen of each sheep to measure dry matter (DM) and neutral detergent fibre (NDF) degradation. ENZ treatment did not affect (P>0.05) ruminal pH or concentrations of NH3-N and total VFA at any sampling time. In contrast, at 0 and 4 h after feeding, molar proportion of propionate tended (P<0.10) to be greater and acetate:propionate ratio tended (P<0.10) to be lower in ENZ-supplemented sheep. No effects of ENZ (P>0.10) were detected 8 h after feeding. Both the ruminally insoluble potentially degradable fraction (b) of grass hay DM and its fractional rate of degradation (c) were increased (P<0.05) by ENZ treatment. Supplementation with ENZ also increased (P=0.009 to 0.023) effective and potential degradability of grass hay DM and NDF. Ruminal fluid endoglucanase and xylanase activities were greater (P<0.05) at 4 h post-feeding in ENZ-supplementd sheep than in control animals. ENZ supplementation did not affecf (P=0.151 to 0,815) either exoglucanase or amylase activity at any sampling time.The authors wish to acknowledge the financial support received from the M.C.Y.T. of Spain (Proyect AGL2001-0130) and Junta de Castilla y León (LE040A05). L. A. Giraldo gratefully acknowledges receipt of a grant from the Fundación Carolina.Peer reviewe

Efecto de la relación forraje: concentrado en raciones completas para el ganado ovino. 1. Ingestión voluntaria y digestibilidad

3 páginas, 3 tablas.-- Ponencia presentada a las VIII Jornadas sobre Producción Animal (AIDA) (Zaragoza, 11 al 13 de mayo de 1999). Publicada en un número especial de la revista ITEA.El empleo de raciones "completas" o "integrales" en la alimentación de los rumiantes presenta ventajas técnicas (simplificación del manejo, ajuste de las dietas y abaratamiento de costes) frente al manejo más tradicional de la alimentación consistente en suministrar los forrajes y el concentrado separadamente. Además de estas ventajas, el efecto negativo de la ingestión de grandes cantidades de concentrado sobre la digestión ruminal, la ingestión de forrajes y la producción de leche se atenúa cuando se ingieren como parte de una ración completa (Mould, 1988; Varga y Kolver, 1997). El uso de este tipo de raciones en la alimentación del ganado ovino podría suponer las mismas ventajas técnicas que han hecho tan común su empleo en la alimentación del vacuno de leche. Sin embargo, tal uso precisa de la determinación de parámetros tan básicos como la ingestión voluntaria, cuyo conocimiento es imprescindible para la planificacion de los sistemas productivos (Orskov, 1998). El presente trabajo se planteó para estudiar la ingestión voluntaria y la digestibilidad por el ganado ovino de raciones completas con distinto contenido en concentrado.Este trabajo ha sido financiado por la C.I.C.Y.T. (Proyecto AGF94-0026)Peer reviewe

Analysis of microbial populations in Rusitec fermenters fed diets of variable composition

Trabajo presentado al : Joint Annual Meeting. ADSA-ASAS. Orlando Florida (USA), julio, 2015. T485Fermenters are widely used to study ruminal fermentation, but infonnation on microbial populations developing in fermenters over the incubation period is limited. Four Rusitec fermenters were fed 2 diets representative of those administered to dairy sheep (DAI; 50:50 alfalfa hay:concentrate) and fattening lambs (FAT; 15:85 barley straw:concentrate) in a crossover design with 2 14-d incubation periods to assess the evolution of the microbial populations. There were 4 fermenters per diet. The fermenters received daily 30 g of diet DM and samples from liquid (LIQ) and solid (SOL) digesta were taken on d 3, 8 and 14, and stored frozen at-80ªC until DNA extraction. Concentrations ofbacterial and protozoal DNA and relative abundance offungi and methanogenic archaea to total bacteria! DNA concentration were detennined by real time PCR using previously validated primers and DNA from bacteria and protozoa isolated from sheep rumen as standards. Data were analyzed as a mixed model with repeated measnres using the PROC MlXED of SAS. The model included diet, incubation nm, time, and diet x tin1e as fixed effects, and fermenter as a random effect. Diet x sampling time interactions (P > 0.05) were detected for bacteria! and protozoal DNA concentrations in both digesta phases. The bacteria! DNA concentrations in SOL did not change (P = 0.002) over the incubation period, whereas concentrations in LIQ increased (P < 0.001) by 1.5 and 1.8 times for DAI and FAT diets by the end ofthe incubation, respectively. Protozoal DNA concentrations on d 14 were 37.8 and 8.0 times lower (P < 0.001; means across diets) than those on d 3 for SOL and LIQ phases, respectively. Relative abundance offungi decreased (P < 0.05) with time in both phases, and that ofmethanogenic archaea remain unchanged in LIQ and increased (P = 0.021) in SOL. Concentration of bacteria! and protozoal DNA and the relative abundance of methanogenic archaea were greater in the fermenters fed the DAI diet (P < 0.05) compared with FAT diet. The results show that microbial populations in Rusitec fermenters are affected by the incubated diet and change over the incubation periodPeer reviewe

Potencial del aceite de ajo para reducir la producción de metano en el rumen: estudios in vitro

1 página.-- Póster presentado al primer Workshop sobre mitigación de emisión de gases de efecto invernadero provenientes del sector agroforestal (Bilbao, España, 8 al 9 de Marzo, 2012).Varios estudios han mostrado el potencial del aceite de ajo (AA) para reducir la producción de metano en el rumen, pero los resultados han sido variables. Nuestra hipótesis de trabajo fue que los efectos del AA sobre la fermentación ruminal in vitro pueden variar con la dieta incubada y el tiempo de administración Por ello, el objetivo de estos estudios fue analizar los efectos de diferentes dosis de AA sobre la fermentación in vitro de dos dietas tras 16 h de incubación en cultivos no renovados de microorganismos ruminales (CNRMR) o tras 11 días de incubación en fermentadores Rusitec.Este trabajo forma parte de los Proyectos AGL2008-04707-C02-02 y la Acción Integrada AIB2010NZ-00190, financiados por el MICINN.Peer reviewe

Postprandial changes of fiber-degrading microbes in the rumen of sheep fed diets varying in type of forage as monitored by real-time PCR and automated ribosomal intergenic spacer analysis

7 páginas, 4 tablas, 1 figura.Four ruminally cannulated sheep were used in a crossover design to assess the postprandial changes of fiber-degrading microbes in the solid phase of the rumen of sheep fed 2 high-forage diets. The diets had forage: concentrate ratio of 70: 30 (DM basis) and either alfalfa (Medicago sativa) hay (AL) or grass hay (GR) as forage (FOR). Sheep were fed twice daily, and samples from solid rumen digesta were taken at 0, 4, and 8 h after the morning feeding. Postprandial changes of DNA concentrations of all determined microbial populations were similar for the 2 diets. Samples taken at 4 h after feeding had lesser (P < 0.05) concentrations of total bacterial DNA determined with real-time PCR and bacterial diversity and greater (P < 0.05) protozoal DNA concentrations, relative abundance of fungal, Fibrobacter succinogenes, Ruminococcus flavefaciens, and Ruminococcus albus DNA compared with those taken at 0 and 8 h. No effect (P = 0.41 to 0.76) of FOR was detected either on concentrations of bacterial and protozoal DNA or the relative abundance of the 2 Ruminococcus DNA, but GR diet promoted greater (P < 0.001) relative abundance of F. succinogenes and fungal DNA compared with AL diet. Fibrobacter succinogenes was the most abundant (P < 0.05) of the 3 cellulolytic bacteria for both diets, with no differences (P < 0.05) between the 2 Ruminococcus species. Rumen pH and carboxymethylcellulase, Avicelase, and amylase activities were not affected (P = 0.15 to 0.69) by FOR, but xylanase activity was greater (P = 0.01) for GR diet. The influence of FOR on microbial communities in ruminal solid digesta was more evident in the first hours after feeding than at later times after feeding, which highlights the influence of sampling time when investigating dietary effects on rumen function and microbial populations.Spanish C.I.C.Y.T. AGL2004-04755-C02-0101 AGL2008-04707-C02-02 M.E.C. of Spain AP2006-03049Peer reviewe

In vitro study of the rumen and hingut fermentation of starch and cellulose

Special Issue: Fouth Joint INRA-RRI.-- Contributed to: Symposium Gut Microbiology (Clermont-Feerand, France, Jun 21-24, 2004).The ruminal and caecal contents from seven lambs fed a concentrate diet were used to study in vitro fermentation. Four hour incubations were performed without added substrate or with starch and cellulose. There were differences between ruminal and caecal fermentation for most of the studied parameters. Total VFA production and the Ac/Pr ratio were higher (P < 0.001) with caecal than with ruminal inocula in the absence of substrate (721 vs. 261 μmol and 3.65 vs. 2.64, for caecum and rumen, respectively). When starch was incubated with ruminal fluid, total VFA production almost doubled (P < 0.001) the one obtained with caecal contents (3048 vs. 1655 μmol, respectively). Fermentation pattern was also different for both inocula, with lower (P < 0.001) acetate and butyrate and higher (P < 0.001) propionate molar proportions with ruminal fluid when starch was incubated. Methane production was higher (P < 0.05) with ruminal than with caecal fluid (259 vs. 164 μmol, respectively) resulting in a higher (P < 0.01) hydrogen recovery. For cellulose, total VFA production and Ac/Pr ratio were higher (P < 0.01) in the caecal fermentation (697 vs. 320 μmol and 3.73 vs. 1.99, caecum vs. rumen). Molar proportions of the main VFA followed the same trend as with starch. Methane production was higher (P < 0.01) when cellulose was incubated with caecal contents (35.6 vs. 14.2 μmol, caecum vs. rumen), but hydrogen recovery was lower (P < 0.01) than that calculated for ruminal fluid. The results point to a high difference between rumen and hindgut fermentation when both inocula were used for in vitro incubations, showing that the first cannot serve as a model for the stoichiometry of the second.Peer reviewe

Perspectivas y retos de los extractos vegetales como aditivos alimentarios en rumiantes

Peer Reviewe

Effect of malate form (acid or disodium/calcium salt) supplementation on performance, ruminal parameters and blood metabolites of feedlot cattle

10 páginas, 6 tablas.Heifers, 108, housed in 18 pens of 6/pen were used in a 141 d feedlot study. Six pens were randomly assigned to each of the following experimental diets: CON: control (no additive); MA: CON plus 1.08 kg/t of malic acid (0.98 g of malate/g product); and MAL: CON plus 2 kg/t of disodium/calcium malate (0.53 g of malate/g product). Both additives provided 1.1 g of malate/kg of concentrate (as mixed). Concentrate dry matter (DM) intake (kg/pen) and individual animal body weights (BW) were determined every 28 d. At 0,84 and 141 d, ruminal fluid was obtained by ruminocentesis and blood samples were collected via tail venipuncture from 2 heifers/pen (12/diet). At slaughter, individual carcass weights were measured and carcass yield was determined. An in vitro study was also conducted to analyse ruminal fermentation of the 3 experimental diets. Batch cultures were inoculated with ruminal fluid from CON heifers incubated for 17 h at 39 C, and main fermentation parameters were determined (i.e., pH, volatile fatty acids (VFA) and CH4 production, ammonia-N and lactate concentrations, and diet degradability). There were no differences among groups in BW, concentrate DM intake or BW gain at any time during the experiment. At slaughter, there were no differences in hot carcass weight and yield or carcass classification among groups. There were no effects of treatments on ruminal parameters (i.e., pH and concentrations of VFA and lactate), with the exception of NH3-N concentrations, which were higher (P<0.05) for MAL compared with CON and MA groups at 84 d of sampling. Blood metabolites (i.e., glucose, urea-N, lactate) were unaffected by treatments. In the in vitro study, there were no differences among diets in any parameter measured. Under the conditions of this study, supplementation with MA or MAL had no effect on animal performance, ruminal parameters or blood metabolites, and results did not depend on whether malate was administered as the free acid or as the disodium-calcium salt.This study was completed at the experimental cattle farm of Comercial Pecuaria Segoviana, SL (Coca, Segovia, Spain). Funding was provided by the Spanish Ministerio de Industria Turismo y Comercio within PROFIT funding program (FIT060000200511) and Centro para el Desarrollo Tecnológico Industrial (CDTI; IDI-20050617).Peer reviewe