Nesting and floor laying by domestic hens in a commercial flock

1. The nesting behaviour of broiler breeders was studied in a commercial flock of nearly 4000 birds kept on deep litter by tagging a sample of 200 hens. Use of nest boxes by tagged birds was recorded on 52 d over 34 weeks.

2. Forty hens were never observed in nest boxes and 33 others were recorded only in ground‐level boxes. These 73 birds were recorded significantly less often in nest boxes and more often apparently laying on the floor than others. Fewer of them perched during observations and they started doing so later than birds which used raised nest boxes.

3. These results suggested that there were consistent floor layers, which had difficulty reaching raised nest boxes, as found previously in experimental conditions. Many or all floor layers may, however, have used ground‐level boxes sometimes.

4. Hens were inconsistent in their use of particular nest boxes, and some even nested in two distinct areas.

5. Most individuals were, however, consistent in their reaction to one or more features of the nest boxes, including height, aspect and area. Individual choices for these features varied, so no boxes were used particularly heavily, with the exception of those at ground level.     

Wound healing in the European oyster, Ostrea edulis L.

A study was made of wound healing in Ostrea edulis L. to enable comparisons to be made with previous studies in which Crassostrea spp. were studied exclusively. Wound healing in the European genus is much the same but the reaction lacks the gross discoloration and green pigmentation so characteristic of Crassostrea.     

Variations for Fusarium head blight resistance associated with genomic diversity in different sources of the resistant wheat cultivar ‘Sumai 3’

Fusarium head blight (FHB), caused by Fusarium graminearum, is a serious disease of wheat (Triticum aestivum L.) associated with contamination by the mycotoxin deoxynivalenol (DON). The FHB-resistant wheat cultivar ‘Sumai 3’ has been used extensively around the world. The existence of variation in FHB resistance among ‘Sumai 3’ accessions has been discussed. In this study, genetic variation among ‘Sumai 3’ accessions collected from six countries were identified using SSR markers; our results demonstrate unique chromosome regions in Sumai 3-AUT and Sumai 3-JPN (‘Sumai 3’ accessions from Austria and Japan, respectively). Field evaluation indicated strong resistance to FHB in Sumai 3-AUT. The polymorphic rate (number of polymorphic markers/number of available markers × 100) based on a DArT array was 12.5% between the two ‘Sumai 3’ accessions. Genotyping for DNA markers flanking FHB-resistant quantitative trait loci (QTLs) revealed genetic variations for the QTL regions on 5AS and 2DS; however, no variation was observed for the QTL regions on 3BS and 6B. Thus, the variation in FHB resistance among ‘Sumai 3’ accessions in the field is due to genetic diversity.     

The Nutritional and Phytochemical Composition of the Indigenous Australian Pindan Walnut (<Emphasis Type="Italic">Terminalia cunninghamii</Emphasis>) Kernels

Nutritional composition of the kernels of two types of Pindan walnut (Terminalia cunninghamii), a native nut consumed traditionally by Australian Indigenous peoples, is reported for the first time. Results showed that Pindan walnut kernels contained high levels of fat, protein and ash, approximately 50, 30 and 5% fresh basis, respectively. The levels of minerals in the kernels were much higher than common walnuts and macadamia nuts, especially those of phosphorus, magnesium and zinc. The high amounts of polyphenols in the kernels provided strong hydrophilic antioxidant capacities, of up to 2004 mg Trolox equivalents/100 g fresh basis using the hydrophilic oxygen radical absorbance capacity assay. Both free polyphenol content and hydrophilic antioxidant capacities of the kernels were higher than those of macadamia nuts, although the lipophilic oxygen radical absorbance capacity was lower. These preliminary studies indicate high potential for wider use of the Pindan walnut as a novel, nutritious and health-promoting food.     

Evaluating the utility of the Gulf Stream Index for predicting recruitment of Southern New England‐Mid Atlantic yellowtail flounder

The justification for incorporating environmental effects into fisheries stock assessment models has been investigated and debated for a long time. Recently, a state‐space age‐structured assessment model which includes the stochastic change in the environmental covariate over time and its effect on recruitment was developed for Southern New England‐Mid Atlantic yellowtail flounder (Limanda ferruginea). In this paper, we first investigated the correlations of environmental covariates with Southern New England‐Mid Atlantic yellowtail flounder recruitment deviations. The covariate that was most strongly correlated with the recruitment deviations was then incorporated into the state‐space model and alternative effects on the stock‐recruit relationship were estimated and compared. For the model that performed best as measured by Akaike information criterion, we also compared the estimates and predictions of various population attributes and biological reference points with those from an otherwise identical model without the environmental covariate in the stock‐recruit function. We found that the estimates of population parameters are similar for the two models but the predictions differed substantially. To evaluate which model provided more reliable predictions, we quantitatively compared the prediction skill of the two models by generating two series of retrospective predictions. Comparison of the retrospective prediction pattern suggested that from an average point of view, the environmentally explicit model can provide more accurate near‐term recruitment predictions especially the one year ahead recruitment prediction. However, the accuracy of the near‐term recruitment prediction from the environmentally explicit model was largely determined by the accuracy of the corresponding environment prediction the model provides.     

Rapid Screening of Potato Cultivars Tolerant to Nitrogen Deficiency Using a Hydroponic System

Increased cultivar tolerance to nitrogen (N) deficiency may increase productivity and reduce environmental impact of potato crops. In this study we screened 20 cultivars for the tolerance to N-deficient (0.05 mM nitrate) in comparison with N-abundant (7.5 mM nitrate) nitrate supply using plantlets grown for 15 days in a recirculating hydroponic system. Nitrogen deficiency increased the root-to-shoot ratio in 18 cultivars. Plant total dry weight (TDW) was reduced by an average of 61% under N-deficient nitrate supply. Tolerance to N deficiency was assessed as the TDW ratio (TDWR), calculated as the ratio of TDW under N-deficient to N-abundant nitrate supply. The cultivars Norland, Raritan, Nipigon and Langlade were significantly more tolerant to nitrogen deficiency (greater TDWR) than Eramosa, Carleton, and Epicure. The results indicate that the hydroponic system has capacity to rapidly screen a large number of cultivars for tolerance to N deficiency.