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Effects of genotype on the performance and intake characteristics of sheep grazing contrasting hill vegetation communities

  • Osoro, Koldo
  • Oliván, M.C. (María)
  • Celaya, Rafael
  • Martínez, A.
The live-weight responses, voluntary herbage intakes and diet compositions of two breeds of sheep of different mature live weights, grazing two contrasting hill vegetation communities, were studied over three consecutive grazing seasons. A total of 228 Latxa and 255 Gallega non-lactating ewes, with mature live weights of 42.4 and 33.1 kg respectively, grazed two replicates, each of two 5-ha plots comprising by area either 0.3 Calluna vulgaris and 0.7 grass species (Agrostis capillaris, Festuca rubra and Nardus stricta) (treatment C3) or 0.7 C. vulgaris and 0.3 of the above grass species (treatment C7). The Latxa ewes achieved higher rates of live-weight gain than the Gallega ewes under conditions of high availability (sward surface height >3.0 cm) of the preferred grass species (A. capillaris and F. rubra) but had lower rates of live-weight gain in the later part of the grazing season when the availability of the preferred grass species was low. In general, the Latxa ewes had higher voluntary herbage intakes per unit live weight and selected a diet of higher digestibility than the Gallega ewes (P<0.001). The composition of the diet was significantly affected by treatment (P<0.001) and was of a higher digestibility in the earlier part of the grazing season (P<0.001). The results indicate the existence of a significant (P<0.001) genotype X environment interaction affecting diet selection and animal performance. Between-breed differences in diet selection are likely to be important in determining grazing behaviour and thus the suitability of different genotypes for particular environments. Breeds with a small body size are likely to be better suited to the poorer land resources where the availability of preferred species is low.
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Nutritive value of green forage and crop by-products of Cyn&ra cardunculus

  • Cajarville, Cecilia
  • González, Javier
  • Repetto, J.L. (José)
  • Rodríguez, C.A. (Carlos)
  • Martínez, Adela
The nutritive value of cardoon (Cynara cardunculus L.) green forage (GF), dry leaves (DL) and straw (S) was studied from chemical composition analyses and from voluntary intake, digestibility and rumen degradability estimations obtained using adult wethers. Aptitude For bring ensiled according to the wilting period was also evaluated making silages with fresh forage and after 24 and 94 hours of wilting. Green forage had a high nutritive value, as shown by low levels of fibre and lignin and its very high digestibility (86 % for OM). Nevertheless, its voluntary intake was relatively low (64 g DM.kg(-1) LW0.75), although very variable among animals. Fermentation characteristics of the GF silages were good and wilting reduced silage losses andimproved the duality of silages. Nutritive value of DL was high, but limited only by a moderate crude protein content. Supplemented with urea, it hadan OM digestibility similar to a medium-good quality hay (65.9 % average) and a voluntary intake equivalent to a good quality grass (75.9 g DM.kg(-1)LW0.75). Finally, S was a typical fibrous and low protein forage, but whensupplemented with urea, it had an intake and a digestibility higher than those of cereal straws. Variations in digestibility for OM and energy among the different non-preserved Cynara cardunculus forages showed close relationships with fibre fractions, especially with the acid detergent lignin content.
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The effect of Calluna vulgaris cover on the performance and intake of ewes grazing hill pastures in northern Spain

  • Osoro, Koldo
  • Oliván, M.C. (María)
  • Celaya, Rafael
  • Martínez, A.
The effect of the proportion of Calluna vulgaris cover on diet composition, intake and performance of sheep grazing hill vegetation communities in northern Spain is examined. A total of 591 non-lactating Gallega ewes grazed for five consecutive grazing seasons (June to September) on replicated plots of hill pastures (1700 m.a.s.l.) composed principally of Festuca, Agrostis, Nardus and Calluna spp. but with different proportions of Calluna vulgaris cover, either 0·3 (C0·3) or 0·7 (C0·7) of the total area. In 1 year, twenty-eight ewes suckling single lambs also grazed the plots. The mean stocking density over the 5 years was 8·7 ewes ha–1. On treatment C0·3, daily liveweight gains (33 g d–1) of non-lactating ewes were significantly (P < 0·001) greater than on treatment C0·7 (12 g d–1). Likewise in lactating ewes the difference in mean daily liveweight change was 40 g d–1 (–5 vs. –45 g d–1 for C0·3 and C0·7 treatments respectively; P < 0·001). Liveweight gains of lambs were only 80–100 g d–1 from June to August and lambs only maintained live weight during August and September. The effect of lactational status on liveweight changes was not significant. Liveweight gains of non-lactating ewes increased significantly (P < 0·001) from the first to the last year of the experiment on both treatments.The composition of the diet was significantly affected by treatment (P < 0·001), with a higher proportion of grass species on the C0·3 treatment and a higher digestibility of the diet in the first half of the grazing season (P < 0·001). The proportion of C. vulgaris in the diet was significantly (P < 0·001) higher on the C0·7 treatment and increased significantly (P < 0·001) from July to September on both treatments. There were no significant differences in the composition of the diet selected by lactating and non-lactating ewes.The results demonstrate that on hill vegetation communities, in which the grass components (Festuca rubra, Agrostis capillaris, and Nardus stricta) cover at least 0·3 of the area and on which the preferred grass component (Festuca and Agrostis spp.) is maintained at a sward height of at least 2·5 cm, non-lactating ewes can increase their live weight and body condition, but this increase is influenced by the proportion and quantity of species of grass in the diet, which is affected in turn by the species of grass available and their nutritive quality. However, ewes suckling lambs were not able to maintain their live weight and body condition except when Calluna cover was 0·3 and grass height was more than 3·5 cm.It is concluded that these indigenous vegetation communities can be used in sheep production systems to complement the use of improved pastures at other times of year. In particular, they can be utilized during the non-lactating period (summer) to increase body condition before the beginning of the mating period in autumn.
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Pathovars of Pseudomonas syringae Causing Bacterial Brown Spot and Halo Blight in Phaseolus vulgaris L. Are Distinguishable by Ribotyping

  • González, A.J. (Ana)
  • Landeras, Elena
  • Mendoza, M.C. (María)
Ribotyping was evaluated as a method to differentiate between Pseudomonas syringae pv. phaseolicola and pv. syringae strains causing bacterial brown spot and halo blight diseases in Phaseolus vulgaris L. Ribotyping, with restriction enzymes BglI and SalI and using the Escherichia coli rrnB operon as the probe, differentiated 11 and 14 ribotypes, respectively, and a combination of data from both procedures yielded 19 combined ibotypes. Cluster analysis of the combined ribotypes differentiated the pathovars phaseolicola and syringae, as well as different clonal lineages within these pathovars. The potential of ribotyping to screen for correlations between lineages and factors such as geographical region and/or bean varieties is also reported.
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Capillary liquid chromatographic determination of neutral phenolic compounds in apple juices

  • Blanco-Gomis, Domingo
  • Fraga, Natalia
  • Mangas, J.J. (Juan)
Capillary liquid chromatography (CLC) is evaluated as an alternative to conventional HPLC to analyse complex phenolics. Several neutral phenolic compounds were separated on a packed-reversed phase fused-silica capillary column, and determined with UV detection. A conventional liquid chromatographic equipment was adapted for such purposes. Application of the proposed method to the quantification of neutral phenols in apple juices is reported. Phenolics are extracted and fractionated into neutral and acidic compounds by means of a C18 solid-phase cartridge. Typical recoveries ranging from 90 to 105% are obtained and reproducibility between extractions is <7% in all cases. Mass detection limits are at the sub-nanogram level.
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The effect of breed-production systems on the myosin heavy chain 1, the biochemical characteristics and the colour variables of Longissimus thoracis from seven Spanish beef cattle breeds

  • Gil, Marta
  • Serra, Xavier
  • Gispert, Marina
  • Oliver, M.À. (M.)
  • Sañudo, Carlos
  • Panea, Begoña
  • Olleta, J.L. (José)
  • Campo, Marimar
  • Oliván, Mamen
  • Osoro, Koldo
  • García-Cachán, M.D. (María)
  • Cruz-Sagredo, Rosario
  • Izquierdo, Mercedes
  • Espejo, Manuel
  • Martín, Marta
  • Piedrafita, Jesús
The effect of breed-production system on the myosin heavy chain 1 (MHC-I), the biochemical characteristics and the colour variables of longissimus thoracis (LT) from seven beef breeds was studied: Asturiana de la Montaña (AM), Asturiana de los Valles (AV), Avileña-Negra Ibérica (A-NI), Bruna dels Pirineus (BP), Morucha (MO), Pirenaica (PI) and Retinta (RE) (Age at slaughter between 368 and 541 days; carcass weight between 249 and 334 kg). Significant differences between breed-production systems were found for all traits evaluated. LT from the MO, a rustic type breed, was the most oxidative (MHC-I, 39.3%; isocitrate dehydrogenase activity, 52 nmol min(-1) mg(-1); pigment content, 188.4 μg acid haematin g(-1)) and showed a low L* value (32.6) and high a* and C* values (24 and 27.2, respectively). In terms of meat colour (L* and a*) the canonical discriminant analysis separated the breeds into two groups, the AV, the PI and the A-NI (the lightest ones) from the AM and the MO breeds (the reddest and darkest) whereas the BP showed an intermediate position. The RE and the A-NI were distinguished from the others by their high intramuscular fat content. Meat colour was affected by the muscle biochemical traits in the breed-production systems studied.
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Estimation of the carcass composition of yearling bulls of ``Asturiana de los Valles'' breed from the dissection of a rib joint

  • Oliván, M.C. (María)
  • Martínez, A.
  • García, P.
  • Noval, G.
  • Osoro, Koldo
To evaluate different methods of estimating bovine carcass composition, seventy yearling bulls of the "Asturiana de los Valles" beef breed were slaughtered and their carcass composition estimated by a commercial dissection of the right half-carcass and by tissular dissection of the 6th and 10th rib of the left half-carcass. Correlation and regression analyses were used to identify the most accurate predictors of carcass composition. In simple regression, the percentage of lean in the 10th rib was the most accurate predictor (r=0.88; P<0.001) of the lean proportion in the carcass and the percentage of fat in the 6th rib was the best predictor (r=0.90; P<0.001) of the carcass fat content. The correlation coefficients for estimating the bone percentage in the carcass from the bone proportion in the ribs (6th and 10th) were low (r=0.63 and 0.51 respectively), although significant (P<0.001) and the coefficient improved when the proportion of lean in the ribs was used as predictor (r=0.78 and 0.70 for the 6th and the 10th rib respectively). In multiple regression, the addition of more regressors of the rib composition and carcass traits, such as carcass hot weight, the carcass fatness score and the weight of the kidney knob and channel fat, led to an improvement (P<0.05) in accuracy for some predictions. The results in general show that the accuracy of the predictions for the carcass composition obtained from dissection of both the 6th and 10th ribs was similar, although the dissection of the 10th rib tended to overestimate the proportion of fat in the carcass. Therefore, considering the carcass quartering method for the extraction of the ribs, it is proposed that dissection of the 6th rib is more appropriate than dissection of the 10th rib so as not to reduce the carcass value and obtain a good estimate of the carcass composition.
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Spanish Chestnut Cultivars

  • Pereira-Lorenzo, Santiago
  • Ramos-Cabrer, A.M. (Ana)
  • Díaz-Hernández, Belén
  • Ascasíbar-Errasti, Javier
  • Sau, Federico
Chestnut (Castanea sativa Mill.) is an important crop in Spain. This inventory of chestnut cultivars complements previous studies. We have located 152 chestnut cultivars in 131 municipalities covering 108.6 ha, with 72 new cultivars in addition to the 80 previously found. Fewer than 50% of these cultivars are extensively cultivated. Chestnuts in Spain are grown from sea level to 1100 m, but are more frequent between 200 and 800 m on northern-facing slopes. Most of the chestnuts are harvested from 25 Oct. to 10 Nov.
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The usefulness of artificial intelligence techniques to assess subjective quality of products in the food industry

  • Goyache, Félix
  • Bahamonde, Antonio
  • Alonso, J.
  • López, S.
  • Coz, J.J. (J.)
  • Quevedo, J.R. (J.)
  • Ranilla, J.
  • Luaces, O.
  • Álvarez, A.
  • Royo, L.J. (Luis)
  • Díez, J.
n this paper we advocate the application of Artificial Intelligence techniques to quality assessment of food products. Machine Learning algorithms can help us to: (a) extract operative human knowledge from a set of examples; (b) conclude interpretable rules for classifying samples regardless of the non-linearity of the human behaviour or process; and (c) help us to ascertain the degree of influence of each objective attribute of the assessed food on the final decision of an expert. We illustrate these topics with an example of how it is possible to clone the behaviour of bovine carcass classifiers, leading to possible further industrial applications.
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Using artificial intelligence to design and implement a morphological assesment system in beef cattle

  • Goyache, Félix
  • Coz, J.J. (J.)
  • Quevedo, J.R. (J.)
  • López, S.
  • Alonso, J.
  • Ranilla, J.
  • Luaces, O.
  • Álvarez, Isabel
  • Bahamonde, Antonio
In this paper a methodology is developed to improve the design and implementation of a linear morphological system in beef cattle using artificial intelligence. The proposed process involves an iterative mechanism where type traits are successively defined and computationally represented using knowledge engineering methodologies, scored by a set of trained human experts and finally, analysed by means of four reputed machine learning algorithms. The results thus achieved serve as feed back to the next iteration in order to improve the accuracy and efficacy of the proposed assessment system. A sample of 260 conformation records of the Asturiana de los Valles beef cattle breed is shown to illustrate the methodology. Three sources of inconsistency were detected: (a) the existence of different interpretations of the trait's definition, increasing the subjectivity of the assessment; (b) the narrow range of variation of some of the anatomical traits assessed; (c) the inclusion of some complex traits in the assessment system. In this sense, the reopening of the evaluated Asturiana de los Valles assessment system is recommended. In spite of the difficulty of collecting data from live animals, further implications of the artificial intelligence systems on morphological assessment are pointed out.
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