Intake, growth and carcass characteristics of lambs consuming low digestible hay and cereal grain

The influence of barley and oat grain supplements on hay dry matter intake (DMI), carcass components gain and meat quality in lambs fed a low quality basal diet was examined. Thirty five crossbred wether lambs (9 months of age) were divided into four groups. After adaptation to a basal diet of 85% oat hay and 15% lucerne hay for one week, an initial group of 11 was slaughtered. The weights of carcass components and digesta-free empty body weight (EBW) of this group was used to estimate the weight of carcass components of the other three experimental groups at the start of the experiment. The remaining three groups were randomly assigned to pens and fed ad libitum the basal diet alone (basal), basal with 300 g air dry barley grain (barley), basal with 300 g air dry oat grain (oat). Supplements were fed twice weekly (i.e., 900 g on Tuesday and 1200 g on Friday). After 13 weeks of feeding, animals were slaughtered and, at 24 h post-mortem meat quality and subcutaneous fat colour were measured. Samples of longissimus muscle were collected for determination of sarcomere length and meat tenderness. Hay DMI was reduced (P<0.01) by both barley and oat supplements. Lambs fed barley or oat had a higher and moderate digestibility of DM, and a higher intake of CP (P<0.05) and ME (P<0.01) than basal lambs. Final live weight of barley and oat lambs was higher (P<0.05) than basal, but this was not reflected in EBW or hot carcass weight. Lambs fed barley or oat had increases in protein (P<0.01) and water (P<0.001) in the carcass, but fat gain was not changed (P>0.05). There were no differences in eye muscle area or fat depth (total muscle and adipose tissue depth at 12th rib, 110 mm from midline; GR) among groups. The increased levels of protein and water components in the carcass of barley and oat fed lambs, associated with improved muscle production, were small and did not alter (P>0.05) any of the carcass/meat quality attributes compared to lambs fed a low quality forage diet. Feeding barley or oat grain at 0.9–1% of live weight daily to lambs consuming poor quality hay may not substantially improve carcass quality, but may be useful in maintaining body condition of lambs through the dry season for slaughter out of season

Morphological Characteristics of Genetically-Modified Pineapple Fruit

Genetic engineering is an attractive method for changing a single characteristic of ‘Smooth Cayenne’ pineapple, without altering its other desirable attributes. Techniques used in pineapple transformation, however, such as tissue culture and biolistic-mediated or Agrobacterium-mediated gene insertion are prone to somaclonal variation, resulting in the production of several morphological mutations (Smith et al., 2002). Fruit mutations can include distortion in fruit shape (round ball, conical, fan-shaped), reduced fruit size, multiple crowns, crownless fruit, fruitless crowns, and spiny crown leaves (Dalldorf, 1975; Sanewski et al., 1992). The present paper describes the variability in fruit-shape mutations between transgenic and non-transgenic fruit, and its subsequent impact on organoleptic characteristics.

The freezing characteristics of wheat at ear emergence

Wheat is occasionally exposed to freezing temperatures during ear emergence and can suffer severe frost damage. Few studies have attempted to understand the characteristics of freezing and frost damage to wheat during late development stages. It was clearly shown that wheat appears to have an inherent frost resistance to temperatures down to −5 °C but is extensively damaged below this temperature. Acclimation, whilst increasing the frost resistance of winter wheat in a vegetative state was incapable of increasing frost resistance of plants at ear emergence. It is proposed that the ability to upregulate frost resistance is lost once vernalisation requirement is fulfilled. Culms and ears of wheat were able to escape frost damage at temperatures below −5 °C by supercooling even to as low as −15 °C and evidence collected by infrared thermography suggested that individual culms on a plant froze as independent units during freezing with little or no cross ice-nucleation strategies to protect wheat from frost damage in the field appear to revolve around avoiding ice nucleation.

Odour sampling. 2. Comparison of physical and aerodynamic characteristics of sampling devices: A review

Sampling devices differing greatly in shape, size and operating condition have been used to collect air samples to determine rates of emission of volatile substances, including odour. However, physical chemistry principles, in particular the partitioning of volatile substances between two phases as explained by Henrys Law and the relationship between wind velocity and emission rate, suggests that different devices cannot be expected to provide equivalent emission rate estimates. Thus several problems are associated with the use of static and dynamic emission chambers, but the more turbulent devices such as wind tunnels do not appear to be subject to these problems. In general, the ability to relate emission rate estimates obtained from wind tunnel measurements to those derived from device-independent techniques supports the use of wind tunnels to determine emission rates that can be used as input data for dispersion models.

Growth and carcass characteristics of cast-for-age Merino ewes fed sorghum-based feedlot diets

Grain feeding low bodyweight, cast-for-age (CFA) sheep from pastoral areas of eastern Australia at the end of the growing season can enable critical carcass weight grades to be achieved and thus yield better economic returns. The aim of this work was to compare growth and carcass characteristics for CFA Merino ewes consuming either simple diets based on whole sorghum grain or commercial feed pellets. The experiment also compared various sources of additional nitrogen (N) for inclusion in sorghum diets and evaluated several introductory regimes. Seventeen ewes were killed initially to provide baseline carcass data and the remaining 301 ewes were gradually introduced to the concentrate diets over 14 days before being fed concentrates and wheaten hay ad libitum for 33 or 68 days. Concentrate treatments were: (i) commercial feed pellets, (ii) sorghum mix (SM; whole sorghum grain, limestone, salt and molasses) + urea and ammonium sulfate (SMU), (iii) SMU + whole cottonseed at 286 g/kg of concentrate dry matter (DM), (iv) SM + cottonseed meal at 139 g/kg of concentrate DM, (v) SMU + virginiamycin (20 mg/kg of concentrate) for the first 21 days of feeding, and (vi) whole cottonseed gradually replaced by SMU over the first 14 days of feeding. The target carcass weight of 18 kg was achieved after only 33 days on feed for the pellets and the SM + cottonseed meal diet. All other whole grain sorghum diets required between 33 and 68 days on feed to achieve the target carcass weight. Concentrates based on whole sorghum grain generally produced significantly (P < 0.05) lower carcass weight and fat score than pellets and this may have been linked to the significantly (P < 0.05) higher faecal starch concentrations for ewes consuming sorghum-based diets (270 v. 72 g/kg DM on day 51 of feeding for sorghum-based diets and pellets, respectively). Source of N in whole grain sorghum rations and special introductory regimes had no significant (P > 0.05) effects on carcass weight or fat score of ewes with the exception of carcass weight for SMU + whole cottonseed being significantly lower than SM + cottonseed meal at day 33. Ewes finished on all diets produced acceptable carcasses although muscle pH was high in all ewe carcasses (average 5.8 and 5.7 at 33 and 68 days, respectively). There were no significant (P > 0.05) differences between diets in concentrate DM intake, rumen fluid pH, meat colour score, fat colour score, eye muscle area, meat pH or meat temperature.

Risk-based surveillance for avian influenza control along poultry market chains in South China: The value of social network analysis.

Over the past two decades, the poultry sector in China went through a phase of tremendous growth as well as rapid intensification and concentration. Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 was first detected in 1996 in Guangdong province, South China and started spreading throughout Asia in early 2004. Since then, control of the disease in China has relied heavily on wide-scale preventive vaccination combined with movement control, quarantine and stamping out. This strategy has been successful in drastically reducing the number of outbreaks during the past 5 years. However, HPAIV H5N1 is still circulating and is regularly isolated in traditional live bird markets (LBMs) where viral infection can persist, which represent a public health hazard for people visiting them. The use of social network analysis in combination with epidemiological surveillance in South China has identified areas where the success of current strategies for HPAI control in the poultry production sector may benefit from better knowledge of poultry trading patterns and the LBM network configuration as well as their capacity for maintaining HPAIV H5N1 infection. We produced a set of LBM network maps and estimated the associated risk of HPAIV H5N1 within LBMs and along poultry market chains, providing new insights into how live poultry trade and infection are intertwined. More specifically, our study provides evidence that several biosecurity factors such as daily cage cleaning, daily cage disinfection or manure processing contribute to a reduction in HPAIV H5N1 presence in LBMs. Of significant importance is that the results of our study also show the association between social network indicators and the presence of HPAIV H5N1 in specific network configurations such as the one represented by the counties of origin of the birds traded in LBMs. This new information could be used to develop more targeted and effective control interventions.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (a) Natural durability of timber.

This project evaluated the timber quality, processing and performance characteristics of 19-year-old Eucalyptus cloeziana (Gympie messmate) and 15-year-old Eucalyptus pellita (red mahogany). Studies were undertaken to evaluate wood and mechanical properties, accelerated seasoning and veneer and plywood production. Above-ground and in-ground durability field tests were established at three locations in Queensland. Ground proixmity tests and L-joint tests were installed to gather data applicable to above-ground, weather-exposed end-use applications, and stake tests were installed to gather data applicable to in-ground, weather-exposed end-use applications.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (b) Accelerated seasoning of sawn timber.

Drying trials were conducted using two species of plantation grown eucalypt timbers: 19-year-old Eucalyptus cloeziana (Gympie messmate) and 15-year-old Eucalyptus pellita (red mahogany). The objective of this study was to gain an understanding of the drying potential of young plantation grown material using accelerated seasoning methods, a process expected to be critcal to the success of plantation hardwood products entering value added markets. The findings are encouraging, indicating that both species can be dried using conventional drying techniques much faster than industry is currently achieving when drying native forest timber. The results suggest that there is a definite drying time advantatge in vacuum drying over conventional methods for 19-year-old E. cloeziana. The findings have shown that through careful schedule manipulation and adjustment, the grade quality can be optimised to suit the desired expectation. As this study was limited to only a small number of trials, time and quality improvements are expected to be realised for both conventional and vacuum drying methods as more research is conducted.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (c) Wood quality and structural properties.

This study provides information about wood quality, structural properties, processing characterists and product suitability of wood harvested from fast-grown hardwood plantations. Wood quality attributes tested included density, extractive content, unit shrinkage, heartwood proportion and sapwood width. Structural properties tested included small clear and full section strength and stiffness, hardness, joint group, visual grade assessment and natural vibration-based grade assessment. The variation between the inner, intermediate and outer heartwood zones and the variation between provenances was also tested. Overall, the wood qualtiy attributes measured for 19 year-old E. cloeziana and 15 year-old E. pellita plantation material fall between those expected from the wood of mature, native forest trees and those found in younger plantation material of the same species.

Evaluation of wood characteristics of tropical post-mid rotation plantation Eucalyptus cloeziana and E. pellita: Part (d) Veneer and plywood potential.

Logs from two hardwood plantations in north Queensland were peeled to assess the veneer and plywood potential of fast-grown tropical plantation eucalypts. After visual grading and veneer recovery calculatios, selected veneers were assembled to produce plywood panels. These were tested for mechanical properties and glue bond strength to determine the suitability of young, fast-grown, tropical eucalytps for panel product applications.

Karyological Characteristics of Lilium ledebourii Boiss and Lilium longiflorum Thunb.

The karyological characteristics of two Lilium species were investigated by aceto-ferric-hematoxylin staining. Chromosome characteristics, including the number and length of the chromosomes, length of their long and short arms, length of the total set of chromosomes, the arm ratio index and relative lengths of chromosome, were measured based on averages for five different metaphase cells. Both species are diploid (2n=2x=24). The karyotype of Lilium ledebourii consisted of 1 pair of metacentric, 4 pairs of submetacentric, 3 pairs of acrocentric and 4 pairs of subtelocentric chromosomes. The karyotype of Lilium longiflorum was comprised of 1 pair of metacentric, 4 pairs of acrocentric and 7 pairs of subtelocentric chromosomes. Chromosomes 5 and 7 in Lilium ledebourii and chromosomes 6 in Lilium longiflorum had a satellite. Karyotypes were classified as 3A by Stebbins classification.