Effects of concentrate or ryegrass-based diets (Lolium multiflorum) on the meat quality of lambs grazing on semi-natural pastures

Abstract

With the objective of studying the effects of production systems on meat quality, 75 Norwegian White Sheep lambs were subjected to one of the following treatments: continuous grazing on a semi-natural lowland pasture until slaughtering (Control); continuous grazing followed by either stall-feeding on concentrate and grass silage or grazing ryegrass pasture for 44 or 24 days before slaughtering (Conc44, Conc24, Rye44, Rye24). Loin samples of M. longissimus dorsi including the subcutaneous fat were analysed for sensory attributes and fatty acid composition. Compared with the control group, a lower intensity of acid taste (P<0.05) and a lower content of C18:3n-6 fatty acids (P<0.001) were observed in the Conc44 group. The n-6/n-3 ratio was higher (P<0.001) in meat tested from the concentrate treatments compared to the ryegrass treatments. These findings indicate that the fattening of lambs on improved pastures or a concentrate-based diet prior to slaughter may alter meat characteristics.     

The Effect of Low-Dose Marine n-3 Fatty Acids on Plasma Levels of sCD36 in Overweight Subjects: A Randomized,Double-Blind,Placebo-Controlled Trial

CD36 is a scavenger receptor involved in lipid uptake and inflammation. Recently, non-cell-bound CD36 (sCD36) was identified in plasma and suggested to be a marker of lipid accumulation in the vessel wall. Marine n-3 polyunsaturated fatty acids (PUFA) may have cardioprotective effects. This study evaluated the effect of marine n-3 PUFA on sCD36 levels in overweight subjects. Fifty overweight subjects were randomized to 1.1 g of n-3 PUFA or 2 g of olive oil daily for six weeks. Neutrophils were isolated at baseline and after six weeks of treatment while an adipose tissue biopsy was obtained at baseline. The content of n-3 PUFA in adipose tissue and neutrophils was analyzed by gas chromatography, while plasma levels of sCD36 were determined using an enzyme-linked immunosorbent assay (ELISA). After six weeks of supplement plasma sCD36 did not differ between supplements (P = 0.18). There was no significant correlation between plasma sCD36 levels and n-3 PUFA in neutrophils at baseline (r = −0.02, P = 0.88), after six weeks supplement (r = −0.03, P = 0.85) or in adipose tissue (r = 0.14, P = 0.34). This study therefore does not provide evidence for a cardioprotective effect of n-3 PUFA acting through a CD36-dependent mechanism.     

Use of Forest Vegetation by Sheep as Recorded by Radio Telemetry

The effect of straw bedding on aggression, production and welfare in loose-housed, pregnant sows was studied in 14 commercial farms, half of them with straw bedding and the other half with a concrete floor. The herds were visited twice and agonistic behaviour was observed. Body lesions, movement disorders and production results were also recorded. There were no significant differences in aggression, body lesions or production results between herds with concrete floor and herds with straw bedding. Movement disorders were more common in herds with concrete floor than in herds with straw bedding. Herds with a high score for movement disorders tended to have a higher percentage of sows returning to oestrus than herds with a low score. Individual data showed no significant correlation between production variables and body lesion score. However, the sows that were culled had a higher mean score for body lesions than the means of both types of farms. Altogether, this study shows that straw bedding was advantageous in preventing leg problems, but the presence of straw did not affect the aggression among sows, the incidence of body lesions or the production results.     

Ferulic acid from aleurone determines the antioxidant potency of wheat grain (Triticum aestivum L.)

Grain is an important source of phytochemicals, which have potent antioxidant capacity. They have been implicated in the beneficial health effect of whole grains in reducing cardiovascular disease and type 2 diabetes. The aim of the present study was to identify the most important antioxidant fractions of wheat grain. It was found that the aleurone content of these fractions was highly correlated with the antioxidant capacity of the fractions (r = 0.96, p < 0.0001). Ferulic acid appeared to be the major contributor to the antioxidant capacity in fractions with higher antioxidant capacity. The contribution of protein was rather limited. It was concluded that the antioxidant potency of wheat grain fractions is predominantly determined by aleurone content, which can be attributed to the presence of relatively large amounts of phenolic compounds, primarily ferulic acid.     

Role of perennial plants in determining the activity of the microbial community in the Negev Desert ecosystem

Perennial plants are known to be one of the most influential parameters in desert ecosystems affecting microbial activity. In this study, we examined the importance of these perennial shrubs and attempted to determine the most influential factor that contributes the most to the ecosystem by separating the physical part and the organic contribution of perennial plants. The study site is located in the northern Negev Desert, Israel, where 50 Hammada scoparia shrubs and 50 artificial plants were randomly marked to be used as a tool for the above objectives. Soil samples were collected monthly in the vicinity of the canopies of both shrubs while control samples were collected from the open areas between the shrubs. All samples were collected from the upper (0–10 cm) and the deeper (10–20 cm) soil layers. The contribution to microbial activity was measured by evaluation of the microbial community functions in soil. The results of the research showed a trend of a strong influence of the perennial H. scoparia shrubs on microbial community function. The functional aspects of the microbial community that were measured were CO₂ evolution, microbial biomass, microbial functional diversity, and the physiological profile of the community. High values for all parameters were observed under the vicinity of the H. scoparia shrubs, while the artificial plants were found to have a weaker effect on the community according to soil depth. The upper-soil layer at both locations (artificial plant canopy and control samples) showed higher values of the functioning parameters than that of the deeper soil layer. The results indicate the importance of the organic contribution (plant litter) in comparison to the physical part of desert shrubs.     

Genetic diversity of the African hexaploid species Solanum scabrum Mill. and Solanum nigrum L. (Solanaceae)

Two hexaploid species of Solanum sect. Solanum are present in Africa: Solanum scabrum and S. nigrum. Solanum scabrum is a widely cultivated species and is used as a leafy vegetable, as a source of medicine and as a source of ink dye. In previous studies a wide range of morphological diversity has been reported in this species and in some studies subspecies have been proposed. Subspecies are also recognized in S. nigrum. However, it has not been established whether or not the morphological differences are reflected at the genomic level. The present study applies AFLPs to study the genetic diversity in S. scabrum and its relationship to geographical provenance, morphological differences and the possible existence of subspecies within S. scabrum and S. nigrum. The data obtained were analyzed with cluster analysis (using UPGMA and NJ). The results indicate that the genetic variation within S. scabrum was higher within accessions than between accessions. Accessions did not cluster according to their geographical provenance, indicating that accessions from different geographical areas were not significantly different genetically. The clustering reflected neither morphological differences nor domestication status (cultivated or wild). The morphological differences exhibited by S. scabrum could be due to selection by farmers for different plant types. The AFLP derived clustering pattern did not segregate the subspecies recognized in S. scabrum and S. nigrum into separate subclusters.     

Positive Streptobacillus moniliformis PCR in guinea pigs likely due to Leptotrichia spp

Streptobacillus moniliformis is a zoonotic bacterium. We obtained positive S. moniliformis PCR results in oral swab samples from guinea pigs from an experimental colony and the breeding colony of origin. Comparison of the DNA sequence of an amplicon with deposited 16S rDNA sequences revealed that Leptotrichia sp. can be the source of a false positive S. moniliformis PCR outcome.     

Effects of variety, cropping year, location and fertilizer application on nutritive value of durum wheat straw

This study was carried out to assess the effects of variety, year, location and level of fertilizer application on chemical composition and in sacco dry matter (DM) degradability of durum wheat straw as well as to understand the relationship between straw quality and agronomic traits of the crop and to assess the possibilities of selecting wheat varieties that combine high grain yield with desirable straw quality. Two local (Arendeto and Tikur sinde) and two improved (Boohai and Gerardo) varieties of durum wheat (Triticum turgidum Desf.) were used in the experiment. The four varieties were grown at two locations (Akaki and Ejere) in the years 2001/2002 and 2002/2003 in 5 x 5 m plots in three replications. Diammonium phosphate and urea fertilizers were applied at four levels (0/0, 32/23, 41/23 and 64/46 kg/ha of nitrogen/phosphorus). Straw quality was assessed based on chemical composition and in sacco DM degradability. Correlation of straw quality with grain and straw yield and with other agronomic characteristics of the crop was determined. The potential utility index (a measure that integrates grain and digestible straw yield) was used for ranking of the varieties. The local varieties had higher crude protein (CP) and lower neutral detergent fibre contents and higher digestibility than the improved varieties. The cropping year and location had significant effect on CP content and degradability of the straw, which could be due to climatic variation. However, the fertilizer level did not have any significant effect on straw quality except that the CP content of the straw tended to increase with increasing level of fertilizer application. Based on the potential utility index the varieties ranked, in a decreasing order, as Tikur sinde > Arendeto > Gerardo > Boohai and the ranking was consistent across years and locations. Except the CP content, straw quality was not negatively correlated with grain and straw yield. This indicates that there is a possibility of selecting varieties of wheat that combine high grain and straw yield with desirable straw quality.     

Increasing daily feeding occasions in restricted feeding strategies does not improve performance or well being of fattening pigs

Background

The natural feeding behaviour of the pig is searching for feed by rooting activities throughout the day; self-feeding pigs randomly space their eating and drinking periods throughout the day consuming ten to twelve meals per day. Pigs in conventional fattening pig production are normally fed 2–3 times daily with the feed consumed within 15 minutes. The aim of this study was to determine if more frequent feedings could improve the performance of conventionally kept fattening pigs.

Methods

The experiment was carried out on 360 fattening pigs (27–112 kg live weight), weighed and assigned to pens stratified by weight and sex. Each treatment group consisted of 180 pigs, allocated to 20 pens with nine pigs in each pen. To evaluate how more feeding occasions affects performance and well-being the pigs were divided into two groups and fed three (control group) or nine (treatment group) times daily. The same total amount of liquid feed was fed to each group and the feed ration was correlated to the live weight of the pigs. All weight and slaughter recordings were made individually and recordings of feed consumption were made pen-wise. At slaughter the stomach of each pig was examined for lesions in the pars oesophagea and scored on a scale from 1–6.

Results

Frequent feeding occasions influenced both performance and status of gastric lesions of the pigs adversely. Pigs in the treatment group grew slower compared to pigs in the control group; 697 g/day (± 6.76) versus 804 g/day (± 6.78) (P < 0.001) with no difference in within-pen variation. There was also a lower prevalence of gastric lesions within pigs in the control group (2.4 (± 0.12) compared to 3.0 (± 0.12) (P < 0.01)). There was a positive correlation between gastric lesions in the treatment group and daily weight gain (r = 0.19; P < 0.01).

Conclusion

Increased daily feeding occasions among group housed pigs resulted in a poorer daily weight gain and increased mean gastric lesion score as compared with pigs fed three times daily. This may be a consequence of more frequently occurring competition for feed in the treatment group. The present study does not support increased daily feeding occasions in fattening pigs.