Dirk Fremaut

Fatty acid profile and oxidative stability of pork as influenced by duration and time of dietary linseed or fish oil supplementation1

In this experiment, the effect of duration and time of feeding n-3 PUFA sources on the fatty acid composition and oxidative stability of the longissimus thoracis (LT) muscle was investigated. Linseed (L) and fish oil (F), rich in alpha-linolenic acid and eicosapentaenoic and docosahexaenoic acid (EPA and DHA), respectively, were supplied equivalent to a level of 1.2% oil (as fed), either during the whole fattening period or only during the first (P1; 8 wk) or second (P2; 6 to 9 wk until slaughter) fattening phase. All diets were based on barley, wheat, and soybean meal and were fed ad libitum. Crossbred pigs (n = 154; Topigs 40 x Piétrain) were randomly allotted to the 7 feeding groups. In the basal diet (B), only animal fat was used as the supplementary fat source. Three dietary groups were supplied the same fatty acid source during both fattening phases (i.e., group BB, LL, and FF). For the other 4 dietary groups, the fatty acid source was switched after the first phase (groups BL, BF, LF, and FL; the first and second letter indicating the diet in P1 and P2, respectively). Twelve animals per feeding group were selected based on average live BW. The LT was analyzed for fatty acid composition; lipid stability (thiobarbituric acid-reactive substances) and color stability (a* value, % of myoglobin pigments) were determined on the LT after illuminated chill storage for up to 8 d. The alpha-linolenic acid, EPA, and docosapentaenoic acid incorporation was independent of the duration of linseed feeding (1.24, 0.54, and 0.75% of total fatty acids, respectively, for group LL). Supplying fish oil during both phases resulted in the greatest EPA and DHA proportions (1.37 and 1.02% of total fatty acids; P < 0.05), but the content of docosapentaenoic acid was not affected. The proportion of DHA was greater when fish oil was administered during P2 compared with P1 (P < 0.05). There was no effect of diet on meat ultimate pH and drip loss or on lipid or color oxidation.

Effect of grazing pastures of different botanical composition on antioxidant enzyme activities and oxidative stability of lamb meat.

The aim of this work was to study the influence of different pastures (Intensive ryegrass, Botanically diverse and Leguminosa rich pastures) on the antioxidant status and oxidative stability of meat from lambs that had been exclusively grazing for three months. Lipid, colour and protein oxidation, α-tocopherol content and activity of antioxidant enzymes (superoxide dismutase (SOD), catalase (Cat) and glutathione peroxidase (GSH-Px)) were measured in Longisimus thoracis et lumborum muscle samples taken 1 day after slaughter. Pasture type significantly affected protein oxidation and the activity of GSH-Px, but no significant differences were found for the α-tocopherol content, colour and lipid oxidation, and the activities of SOD and Cat. Grazing a Botanically diverse pasture induced significantly higher protein oxidation in meat, as measured by the free thiol and carbonyl contents, compared to a Leguminosa rich or Intensive ryegrass pasture (P<0.05). The GSH-Px activity was significantly higher in meat from lambs on the Leguminosa rich pasture compared to the other pasture groups (P<0.01).

Effects of dose and formulation of carvacrol and thymol on bacteria and some functional traits of the gut in piglets after weaning

Two trials were conducted to study the effects of dose and formulation of carvacrol and thymol on bacterial counts, metabolites and functional traits of the gut in weaned piglets. In the first experiment (Exp. I), 25 piglets (28 d, 6.59 ± 0.48 kg BW) were allocated to five dietary treatments: a control diet, or the same diet supplemented with either carvacrol or thymol at doses of 500 and 2000 mg kg−1. In the second experiment (Exp. II), 35 piglets (28 d, 7.99 ± 0.73 kg BW) were assigned to seven dietary treatments: the same control diet as in Exp. I, or this diet supplemented with thymol in one of three formulations (on celite, on alphacel or microencapsulated) at doses of 500 and 2000 mg kg−1. At 11/12 days post-weaning piglets were euthanised, and digesta from stomach, proximal and distal small intestine were sampled for bacteriological and biochemical analysis. Small intestinal tissue was sampled for histo-morphological determinations. In none of the experiments or sections of the gut was the number of bacteria lowered by the carvacrol or thymol supplementation. In Exp. I, the villus/crypt ratio at the distal small intestine for the experimental diets (1.30–1.32) was higher than for the control diet (1.24) (p < 0.05). Thymol fed animals in Exp. II had a lower number of intra-epithelial lymphocytes at the proximal (p < 0.05) and at the distal (p < 0.1) small intestine as compared to control animals. Mean concentration of the active ingredient in the stomach and proximal small intestine for the 2000 mg kg−1 carvacrol diet was 521 and 5 mg kg−1 fresh digesta, respectively, and for the 2000 mg kg−1 thymol diets it ranged between 475 and 647 and between 13 and 24 mg kg−1 fresh digesta, respectively. Cumulative absorption in the proximal small intestine was higher than 90% for all treatments and was not affected by formulation type. These data suggest that carvacrol and thymol can improve gut health, but evidence for clear antimicrobial effects towards the major culturable bacteria of the pig foregut is limited.

Higher sustainability performance of intensive grazing versus zero-grazing dairy systems

Although grazing of dairy cows is an integral part of dairy farming in many European countries, farmers today more often choose for zero-grazing systems, where cows are housed throughout the year. Some studies already compared grazing and zero-grazing systems for specific issues such as labor efficiency, environmental impact, or animal welfare. In our study, we perform a more integrated evaluation, considering relevant ecological, economic, and social aspects. This allows for a balanced and more complete comparison of the sustainability performance of the two production methods. We evaluated ten intensive grazing and ten zero-grazing specialized Flemish dairy farms on the use of nutrients and energy, productivity and profitability, labor input, and animal welfare. In addition, we put special effort in formulating useful management advice for farmers. Therefore, we combined a detailed analysis of the sustainability indicators with an intensive interaction and discussion with farmers and farm advisors. Results show that, on average, the zero-grazing farms performed significantly worse from an ecological and economic point of view. This fact is explained mainly due to a less efficient use of concentrates and byproducts. Social sustainability performance did not differ significantly between the two groups. As a result, the integrated sustainability performance was significantly lower for the zero-grazing group. This finding shows that a further shift from intensive grazing to zero-grazing can move dairy farming in Flanders further away from sustainability. An important advice to improve the ecological and economic performance of zero-grazing farms is to optimize cows’ rations to include more forages and optimize forage production and use. More detailed site- and case-specific management advice for farmers of both groups was provided during a discussion meeting. We consider this an essential additional step to any sustainability evaluation, since progress can only be made when monitoring results are translated into practical measures.

Influence of a marine algae supplementation on the oxidative status of plasma in dairy cows during the periparturient period.

This study was part of a larger study that addressed the effects of marine algae (ALG) supplementation in the ration of high yielding periparturient dairy cows. The objectives were to induce milk fat depression (MFD) in early lactation by feeding docosahexaenoic acid (DHA) from ALG and to determine the effects on milk production, milk components and metabolic status early post partum. This study focuses on the oxidative status in the plasma during the ALG supplementation. Plasma samples were collected from 16 Holstein Friesian cows at the day of parturition and at -1, 2, 4 and 6 weeks relative to calving with half of the cows receiving the ALG supplement (44gDHA/d) from 3 weeks pre partum on. The following parameters were measured in plasma: ferric reducing ability of plasma (FRAP), α-tocopherol level, glutathione peroxidase activity (GSH-Px) and thiobarbituric acid reactive substances (TBARS) concentration. There was a significant effect of time for FRAP and α-tocopherol indicating changes in the plasma oxidative status around parturition. The ALG supplementation was successful in creating a milk fat depression (MFD) but could not improve the energy balance. Feeding of ALG significantly increased lipid peroxidation as measured by TBARS, probably through their high content of n-3 polyunsaturated fatty acids.

LCA of pig feed production: calculating the CO2-emissions of different feed components

Bearing in mind the objectives of this study to investigate the Barbary sheep fertility under our climatic conditions and to evaluate the efficiency of the prostaglandin f2α(pgf2α)injections in induction of fertile estrus in different seasons. For these objectives, some experiments were performed during the period from July,2008 to March, 2009. A total number of 300 Libyan Barbary ewes(3-6 years old, weighing 40-60 kg) was used in this experiment. Ewes were kept in privet farms, fed and managed similarly. Ewes were divided to four season groups(summer, autumn, winter and spring groups). Each season group was divided into treated and control. Animals in the treated groups were injected with double injections of 125 μg of prostaglandin f2α intramuscularly(i/m), 11 days apart. While those in control groups were injected with two injections of 1.0 ml of 0.9% NACL saline solution simultaneously with the treated ewes. At the same day (day 11) rams wearing painted sponges on their briskets regions were introduced for natural mating. Treated groups showed shorter estrus response time than control groups in all seasons(P<0.05). Estrus duration was longer in winter and spring than in summer and autumn (P<0.001),but no difference was found between treated and control groups inside seasons. Treated group showed higher pregnancy rate(P<0.001) in winter season than control group. Percentage of ewes lambed in winter was significantly high (P<0.001) among treated ewes than control (80 vs 38%). Lambing rate differed significantly (P<0.001) among treated groups in all seasons. Data were collected and calculated statistically using SPSS system for percentages, means, standard deviation(mean ± sd) analysis of variance (anova), Chi square and Dunacan’s test were used accordingly. Other values were measured, calculated and analyzed similarly. Adoption of technology in sheep farms of La Mancha, Spain J. Rivas1, C. De Pablos2, J. Perea1, C. Barba1, R. Dios-Palomares1, M. Morantes1 and A. García1 1Universidad de Córdoba, Campus Rabanales, 14014, Córdoba, Spain, 2Universidad Rey Juan Carlos, Paseo de los Artilleros, 28034, Madrid, Spain; pa1gamaa@uco.es Recently in Spain the milk production coming from sheep farms shows higher degrees of specialization based on the adoption of technologies. The aim of this research is to examine the pattern of adoption of technologies in sheep farms of La Mancha. Based on previous researches, from 77 questions, only 38 questions were selected by using qualitative and participatory methods; the chosen variables were grouped into six technology packages (TP): management, feeding, animal health and milk quality, pasture and land use, equipment and facilities, and reproduction and breeding program. The survey was applied to a sample of 157 farms. Using descriptive statistics each TP was characterized and the pattern of adoption was determined. The average of technologies adopted was of 18.4±6.0 (48.3%). TP showing higher degrees of implementation are animal health and milk quality (67.8%), feeding (56.0%) and management (55.7%), but their adoption is not sequential or responds to independent events. This research facilitates the identification of a number of technologies that must be implemented from an organizational strategy point of view. Moreover, all technologies are seeking a dynamic balance system that allows firms migrate to more efficient processes without losing their main attributes. As a technological challenge, an andrologic evaluation of ram, gynecologic evaluation of ewes prior to mating, early detection of non-productive animals are proposed; and a better use of productive records for the decision-making; aspects are recommended. The results of this analysis will have an impact on future research that attempts to improve the use of subproducts, forage reserves and improved rangeland management and hygiene control system, taking the quality milk as an strategic asset, so further research is necessary to assess the impact of each technology on the operating of the mixed system in the Mancha region. Session 40 Poster 20 Session 40 Poster 19In Italy, as in other European countries, since 2005 a program of selection for scrapie resistance in sheep, based on the PRNP polymorphism, has been implemented with the aim of increasing ARR ‘resistant’ allele and eliminating VRQ ‘susceptible’ allele. In a small breed, the ARR-carriers may be more related to each other than ranndomly chosen animals; as a consequence, for an equal number of reproducers the effective size may be smaller than expected in a pure genetic drift condition (1). In the Sambucana sheep breed (reared in Piemonte region, north-west Italy) the ARR allele frequency was higher than in other breeds, like Biellese for example, before the selection plan started (2). On the other hand, due to the reduced number of animals (3500), this breed is considered at risk of extinction (Piemonte Regional Rural Development Plan for 2007-2013 period). The aim of the present investigation was to evalute the impact of scrapie resistance selection on genetic variation of the Sambucana. INTRODUCTIONCONCLUSIONS During the last decade there has been growing scientific interest in the use of genomic information as an additional tool in conventional dairy cows’ breeding schemes. It is now well established that dairy cows’ fertility has declined during the last decades and this may not be remedied only by improved management. Given that there is a substantial genetic background in this decline, emphasis should be placed in efforts to improve dairy cows’ fertility through genetic selection. Although there are substantial genetic effects that contribute to this infertility, little progress has been made on the identification of major genes affecting reproduction traits. There is an urgent need to identify the genetic factors responsible for the decline in fertility in cattle. The objective of this study was to investigate the association of two specific polymorphisms, the SNP12195 and SNP11646 polymorphisms of the Signal Transducer and Activator of Transcription 5A (STAT5A) and Fibroblast Growth Factor 2 (FGF2) genes respectively with fertility in cattle. These genes have been previously reported to be associated with in vitro fertilization and embryonic survival rate in cattle.In European grasslands, grazing and mowing regimes are major drivers of the maintenance of many wild species, either through direct or indirect effects. To date, both types of effects were studied separately, mainly at the field scale and with no quantification of performance. Objective of this study was to model the trade-offs between ecological and productive performance of a grassland agro-ecosystem at two nested scales i.e. field and farm scales. We developed a dynamic model linking grass dynamics controlled by grazing or mowing to stochastic population dynamics of two grassland bird species. Bird dynamics were driven by both direct and indirect effects of management. Viable control framework was used to predict productive and ecological performance. At field scale, results showed that the best ecological performance was obtained at intermediate levels of productive performance (60 to 108 grazing days /ha /year). Above 108 grazing days, no grazing strategy was viable for either species due to the negative direct effects of management. Between 108 and 240 grazing days, the ecological-productive relationship showed a concave Pareto like frontier. Any improvement in productive performance entailed a strong decrease in ecological performance. As expected, at farm scale the best ecological performance was obtained with extensive farms. However, the ecological-productive relationship showed a convex Pareto like frontier indicating the occurrence of compensations among management regimes. In intensive farms, it was necessary to allocate 40% of farm area in low-intensity grazing in order to compensate for the negative effects of mowing and high-intensity grazing on birds. However this land allocation involved a 25% reduction in productive performance. Finally, we explore several forms of complementarities among farm types to improve overall performance.