Effects of different forms and origins of oilseeds on dynamics of ruminal biohydrogenation of long‐chain fatty acids in vitro

Dietary unsaturated fatty acids (FA) are intensively hydrogenated in the rumen, resulting in reduced amount of poly‐unsaturated fatty acids (PUFA) and accumulation of several biohydrogenation (BH) products. In this study, BH of PUFA originating from different oilseeds (linseed, soya beans, sunflower seed and rapeseed) present in crushed oilseeds or their free oils were assessed in vitro. The assay substrates were incubated in buffered rumen fluid for 0, 6, 12 and 24 h. After incubation, the FA pattern of the incubated samples was analysed using gas chromatography. Biohydrogenation is defined as disappearance of double bonds (DB) calculated from the contents of unsaturated FA. After 24‐h incubation, the DB contents of all oilseeds were reduced (p < 0.001) by 40–60%. The reduction was higher (p < 0.001) for the crushed form compared with the oil form. In addition, linseed and sunflower seed known as oilseeds with high contents of linolenic acid C18:3 c9,12,15 (LNA) and linoleic acid C18:2 c9,12 (LA), respectively, showed a higher (p < 0.001) accumulation of the BH intermediates conjugated linoleic acid (CLA, isomer C18:2 c9t11) and vaccenic acid (C18:1 t11) for the crushed form, when compared with the oil. These results suggest an inherent effect of the physical form of the assay oilseeds on in vitro BH. Changes in FA pattern during BH in vitro can be attributed to both source and physical form of the assay oilseeds. However, further investigations are warranted to ensure whether the observed in vitro effects on ruminal BH can be confirmed in vivo.     

Do early infant feeding practices vary by maternal ethnic group?

OBJECTIVE: To examine UK country and ethnic variations in infant feeding practices. DESIGN: Cohort study. SETTING: Infants enrolled in the Millennium Cohort Study, born between September 2000 and January 2002. SUBJECTS: A total of 18 150 natural mothers (11 286 (8207 white) living in England) of singleton infants. OUTCOME MEASURES: Breast-feeding initiation, breast-feeding discontinuation and introduction of solid foods before 4 months. EXPLANATORY VARIABLES: Maternal ethnic group, education and social class. RESULTS: Seventy per cent of UK mothers started to breast-feed, of whom 62% stopped before 4 months. Median age at discontinuing breast-feeding was 14, 13, 10 and 6 weeks in Scotland, England, Wales and Northern Ireland, respectively. Thirty-six per cent of UK mothers (34% in England) introduced solids before 4 months. White mothers were more likely to discontinue breast-feeding (62%) and introduce solids early (37%) than most other ethnic minority groups; those stopping before 4 months were more likely to introduce solids early compared with those continuing to breast-feed beyond this age (adjusted rate ratio (95% confidence interval): 1.3 (1.1-1.2)). Educated mothers were less likely to stop breast-feeding before 4 months (white mothers, 0.8 (0.8-0.9); non-white mothers, 0.9 (0.8-1.0)) than those with no/minimal qualifications but, among ethnic minorities, were more likely to introduce solids early (1.3 (1.0-1.6)). Socio-economic status was positively associated with breast-feeding continuation among white women, and with age at introduction of solids among non-white women. CONCLUSIONS: We have identified important geographic, ethnic and social inequalities in breast-feeding continuation and introduction of solids within the UK, many of which have not been reported previously. The factors mediating these associations are complex and merit further study to ensure that interventions proposed to promote maternal adherence to current infant feeding recommendations are appropriate and effective.     

Slug control in Australian canola: monitoring, molluscicidal baits and economic thresholds

Exotic slugs have become serious pests of canola, at establishment, in Southern Australian high-rainfall cropping zones. Slugs were monitored using relatively inexpensive 300 mm x 300 mm terracotta tiles acting as refuges. An investigation was made of the effects of the time of application of chelated iron baits on the slug species Deroceras reticulatum Müller and Lehmannia nyctelia Bourguignat. Baits reduced the number of surface-active slug species. A single application at sowing provided greater efficacy than one application before sowing, and efficacy was comparable with that of two applications. Canola seedling densities showed a negative response to D. reticulatum numbers; the presence of even one individual per refuge trap reduced seedling numbers below optimum densities. Thistles and other vegetation were associated with increased numbers of slugs. European guidelines for slug monitoring and damage appear to be at least partly applicable to Australian conditions.     

Prediction of total phenols,condensed tannins,and 3-deoxyanthocyanidins in sorghum grain using near-infrared (NIR) spectroscopy

The reported high phenolic levels in sorghum have led an interest from sorghum breeding programs in developing and identifying germplasms with high phenolic levels, which require screening a large number of samples to find those with the highest levels. Since wet chemistry screening methods are slow, expensive, and destructive, the use of NIR calibration curves could be an alternative. The objectives of this project were to determine the variation range in total phenols, condensed tannins, and 3-deoxyanthocyanidin levels in a diverse set of sorghum genotypes and to assess the predictive value of NIR curves to estimate these compounds in sorghum. A calibration curve to estimate each compound was developed and validated with an independent validation set. Calibration curve correlations for total phenols, condensed tannins, and 3-deoxyanthocyanidins were r = 0.98, 0.97, and 0.99, respectively. Correlations between NIR-predicted values and reference values in the validation set were significant for total phenols (r = 0.93), condensed tannins (r = 0.81) and 3-deoxyanthocyanidin (r = 0.82). These indicated that sufficient variation for these compounds existed within sorghum and that NIR calibration curves could be used to rapidly and non-destructively predict total phenols, condensed tannins, and 3-deoxyanthocyanidins concentrations in whole grain sorghum.     

Australian sperm whales from different whaling stocks belong to the same population

1. Understanding the factors driving population structure in marine mammals is needed to evaluate the impacts of previous exploitation, current anthropogenic threats, conservation status, and success of population recovery efforts.
2. Sperm whales are characterized by a worldwide distribution, low genetic diversity, complex patterns of social and genetic structure that differ significantly within and between ocean basins, and a long history of being commercially whaled. In Australia, sperm whales from the (International Whaling Commission assigned) southern hemisphere ‘Division 5’ stock were very heavily exploited by whaling.
3. The present study assessed the potential effects of whaling on the genetic diversity of sperm whales in Australia and the population genetic structure of these whales within a global context. A combination of historical and contemporary sperm whale samples (n = 157) were analysed across six regions, from south-eastern Australia (‘Division 6’ stock in the Pacific Ocean) to south-western Australia (‘Division 5’ stock in the Indian Ocean).
4. Sperm whales sampled from the ‘Division 5’ and ‘Division 6’ stocks belong to the same population based on nuclear and mitochondrial DNA (mtDNA) analyses. Four novel sperm whale mtDNA haplotypes were identified in animals from Australian waters. Levels of genetic diversity were low in Australian sperm whales but were similar to those previously reported for populations in the Indian and Pacific Oceans.
5. Given the genetic distinctiveness of sperm whales in Australian waters from other regions in the Pacific and Indian Oceans, and the lack of recovery in population numbers, further scientific studies are needed to increase our understanding of population dynamics and the effectiveness of threat management strategies in this species.

     

Mittheilungen der Raiferlichen freien öfonomifchen Gefellfchaft zu St. Betersburg. 6 Hefte. 1856fonomifchen Gefellfchaft zu St. Betersburg. 6 Hefte. 1856

Ohne Zusammenfassung Der Jahrgang 1855 ift in ber Württemb. forftl. Monatfchrift, 1856 Seite 217, angezeigt.     

Effect of the nutrition level and sex on the energy maintenance requirement of broilers and rats

In 3 experiments young broiler chickens were supplied on various feeding levels in the growth range between 200 and 2500 g live weight (2.8 and 2.0 in experiment 1, 2.8, 2.3 and 1.8 in experiments 2 and 4, maintenance = feeding level 1.0). In experiments 1 and 2 short-time measurings (30 min) of heat production by means of gas exchange were made at 500, 1000, 1500 and 2000 g live weight in the post-absorptive state and on the maintenance level of feeding. In experiment 1 the heat production of the restrictively fed chickens was in 3 out of the 4 stages of development studied significantly lower by 10-14% than that of the intensively fed ones. In experiment 2 such an effect could not be observed. Fed on the level of energy maintenance, broilers weighing approximately 2000 g (experiment 3) did not show a significant influence of the sex on heat production as a result of 30-minute gas exchange measurings in the post-absorptive state. In experiment 4 24-hour measurings of the energy metabolism were carried out in the growth development in periods of feeding on the maintenance level by means of indirect calorimetry. In the live weight range between 0.9 and 1.3 kg there was only a low, non-significant decrease of the energy maintenance requirement of 4-6% of the highly restrictively fed chickens in comparison to the intensively fed ones. After continued feed restriction (live weight range 1.7-2.2 kg) an energy maintenance requirement reduced by 17% was measured. In an analogously arranged experiment with 24-hour energy metabolism measurings (experiment 5) male Wistar rats in the growth range between 70 and 280 g were supplied on the feeding levels 1.8 and 1.4 resp. In all three periods studied on the feeding level maintenance--beginning at 140-150 g live weight--the highly restrictively fed animals showed a slightly reduced energy maintenance requirement by 8%, 3% (non-significant) and 6% in comparison with the intensively fed animals.