Lipid Oxidation and Colour Stability of Lamb and Yearling Meat (Muscle Longissimus Lumborum) from SheepSupplemented with Camelina-Based Diets after Short-,Medium-, and Long-Term Storage.

This study investigated the impact of feeding pelleted diets containing camelina (Camelina sativa L. Crantz) hay (CAHP) or camelina meal (CAMP) as a supplement compared with a control pellet (CONP) diet, without vitamin E fortification. The fatty acid profile, retail colour, and lipid oxidative stability of lamb and yearling meat (m. longissimus lumborum) stored for short-, medium-, or long-periods (2 days (fresh), 45 days and 90 days) under chilled to semi-frozen conditions were determined. The CAMP diet altered key fatty acids (p < 0.05) in a nutritionally beneficial manner for human health compared to the other diets, with increased total omega-3, decreased omega-6 fatty acids and decreased omega-6/omega-3 ratio of muscle. Muscle vitamin E concentration was lower (p < 0.05) for both camelina diets (CAMP and CAHP) when compared with the CONP diet, with the average concentrations less than 1 mg/kg muscle for all three treatments. Animal type and storage length were factors that all affected (p < 0.05) colour and lipid oxidative stability of meat. These results emphasise the importance of vitamin E concentration in meat stored for extended periods under semi-frozen conditions to maintain desirable meat colour during retail display, and to avoid off-flavour development of the cooked meat.

Effects of Positive Human Contact during Gestation on the Behaviour, Physiology and Reproductive Performance of Sows.

Previous positive interactions with humans may ameliorate the stress response of farm animals to aversive routine practices such as painful or stressful procedures, particularly those associated with stockpeople. We studied the effects of positive handling by providing younger (parity 1-2) and older (parity 3-8) sows housed in pens of fifteen (n = 24 pens in total) with either positive human contact (+HC) or routine human contact (control) during gestation. The +HC treatment involved a familiar stockperson patting and scratching sows and was imposed at a pen-level for 2 min daily. Measurements studied included behavioural, physiological and productivity variables. The +HC sows showed reduced avoidance of the stockperson conducting pregnancy testing and vaccination in the home pens, however the behavioural and cortisol responses of sows in a standard unfamiliar human approach test did not differ. There were no effects of +HC on aggression between sows, serum cortisol or serum brain-derived neurotrophic factor concentrations during gestation, or on the behavioural and cortisol response to being moved to farrowing crates. There were also no effects of +HC on the maternal responsiveness of sows, farrowing rate or the number of piglets born alive, stillborn or weaned. Sows in the +HC pens reduced their physical interaction with the stockpeople imposing the treatment after 2 weeks, which suggests the sows may have habituated to the novel or possible rewarding elements of the handling treatment. This experiment shows that regular positive interaction with stockpeople does reduce sows' fear of stockpeople, but does not always confer stress resilence.

Effect of Covering a Visitor Viewing Area Window on the Behaviour of Zoo-Housed Little Penguins (Eudyptula minor).

Studies on the effects of visitors on zoo animals have shown mixed findings and as a result, the manner in which visitors affect zoo animals remains unclear for many species, including a rarely studied taxa such as penguins. Penguins are a common zoo-housed species and have been shown to display huddling, vigilance and avoidance towards zoo visitors which can be indicative of fear. Here, we examined the effects of covering one visitor viewing area window, out of four, on little penguin (Eudyptula minor) behaviours that may be indicative of fear. Two treatments were randomly imposed on different days: (1) The main visitor viewing area window, where most visitor-penguin interactions occurred, was uncovered ('Main window uncovered') and (2) The main visitor viewing area window was covered ('Main window covered'). Penguin numbers and behaviour were recorded near the main visitor viewing area window and the three other visitor viewing area windows, as well as one area not visible to visitors ('Corner' area). Furthermore, visitor numbers and visitor behaviour were recorded at all four visitor viewing area windows. Covering the main visitor viewing area window reduced the proportion of visitors present at this window by about 85% (p < 0.001) and reduced potentially threatening visitor behaviours at this window such as tactile contact with the window, loud vocalisations and sudden movement (p < 0.05). When the main visitor viewing area window was covered, the proportion of penguins present increased by about 25% (p < 0.05), the proportion of visible penguins preening in the water increased by about 180% (p < 0.05) and the proportion of visible penguins vigilant decreased by about 70% (p < 0.05) in the area near this main window. A preference for the Corner area was also found whereby 59% and 49% of penguins were present in this area when the main window was uncovered and covered, respectively. These results provide limited evidence that the little penguins in this exhibit showed an aversion to the area near the main visitor viewing area window when it was uncovered based on the increased avoidance and vigilance and decreased preening in the water in this area. This suggests visitors may be fear-provoking for these little penguins. However, it is unclear whether visual contact with visitors per se or other aspects of visitor contact, such as visitor-induced sounds and vibrations, were responsible for this apparent aversion when this window was uncovered.

Understanding the impact of sire lean meat yield breeding value on carcass composition, meat quality, nutrient and mineral content of Australian lamb.

Advances in genomics and technology measuring body composition are now allowing sheep producers to select directly for increased lean meat yield (LMY) using Australian Sheep Breeding Values (ASBV). This experiment evaluated the impact of sire LMY ASBV on carcass composition, meat quality, nutrient and mineral content for lambs reared at pasture and finished in a feedlot. A 1% unit increase in sire LMY ASBV resulted in progeny that were leaner (0.8%) and had less fat (1.0%) on carcass. There was also a 0.2% reduction in the intramuscular fat content, a 3.2 N increase in meat toughness determined by shear force at day 5 ageing, a reduction in the redness of the fresh meat and a lower iron content. It is concluded that Australian sheep producers will need to incorporate ASBVs for other aspects of meat quality when selecting sires with increased LMY to avoid deterioration in meat quality, nutritional content of lamb and fresh meat colour.

Understanding the action of muscle iron concentration on dark cutting: An important aspect affecting consumer confidence of purchasing meat.

We investigated the association of muscle iron concentration, in addition to ultimate pH (pHU), on dark meat formation in sheep of different breeds fed forage-based diets. At 1 h simulated display, redness of meat (a*-value) increased (P < .0001) by about 3 units as the iron concentration increased from 10 to 22 mg/kg of meat, whereas the a*-value decreased by 2 units as pHU increased from 5.5 to 6.2 in fresh meat (P < .0001). After 90 days storage the corresponding responses were about 2 units increase for iron concentration and about 1 unit decrease for pHU, respectively. The results clearly show that increased muscle iron concentration was strongly associated with reduced dark cutting in fresh and stored meat evaluated at 1 h simulated display. We conclude that it may be desirable to measure iron concentration, along with pHU, for evaluation of the potential for carcasses to produce dark cutting meat, and for the meat to turn brown during display.

Residues and Dissipation of the Herbicide Imazapyr after Operational Use in Irrigation Water.

Imazapyr is a herbicide that can be used in irrigation canals to control a range of aquatic weed species, however, its residual nature, combined with its phytotoxicity to crops at low concentrations, means that the water in canals must be carefully managed following imazapyr application. Residues of the herbicide imazapyr (isopropylamine salt) in irrigation water were analysed and modelled after application to irrigation canals in south-eastern Australia. A treatment program to control delta arrowhead (sagittaria; Sagittaria platyphylla (Engelm.) J.G. Sm.) in over 400 km of irrigation canals was enacted by applying imazapyr to dewatered canals during winter. Following imazapyr application, canals were left dewatered for a period (up to eight weeks) and then refilled. After refilling, canals were ponded for a period (up to 28 days) to allow degradation of imazapyr in the water via photolysis. Upon refilling canals, ~650 water samples containing imazapyr were collected across the treatment area and data modelled to measure the extent of water contamination and to guide efforts to reduce the subsequent irrigation hazard to crops. Modelled data demonstrates that imazapyr behaviour in irrigation water following canal refilling was predictable when 1) amount of imazapyr applied, 2) the dewatered period following herbicide application, 3) the water ponding period, and 4) solar exposure during water ponding were taken into account. Minimising the amount applied (g imazapyr per km of canal) and maximising the time between spraying and refilling (dewatered period) reduced the initial concentration in the water following canal refilling. The amount of imazapyr in the canal water following refilling was reduced by half for every 16 days (confidence interval = 10-38 days) that the canal remained dewatered after imazapyr application. Imazapyr dissipation during the ponding period following canal refilling occurred at a rate that depended on solar exposure. Dissipation did not occur when solar exposure was <8.5 MJ m-2. However, when solar exposure was >10 MJ m-2, imazapyr concentration in the water reduced by half for every 4.4 days of ponding period (confidence interval = 2.9-9.5 days). Our two models, combined with local climate data on solar exposure, can be used by canal managers to determine the optimal time to refill canals so that imazapyr dissipation is maximised, and thus risk of damaging irrigated crops is minimised.

The Human-Animal Relationship in Australian Caged Laying Hens.

Studies on farm animals have shown relationships between stockperson attitudes and behaviour and farm animal fear, stress and productivity. This study investigated how the avoidance behaviour of Australian commercial caged laying hens may be related to stockperson behaviour, albumen corticosterone, and the number of weeks producing within 5% of peak egg production. Nineteen laying houses were assessed over 3 days. Fear of humans in hens, based on their avoidance response to an unfamiliar human, was assessed using two behavioural tests. Albumen corticosterone concentrations were measured from egg samples collected immediately prior to behavioural testing. Stockperson attitudes were assessed using a questionnaire and stockperson behaviour was observed over 2 days. Productivity records for each laying house were also obtained. The duration of peak production was negatively related to both noise made by the stockperson and hen avoidance. No relationship between stockperson behaviour or attitudes and hen avoidance was found, but stockpeople with negative attitudes made more noise. In conclusion, this study could not confirm a relationship between stockperson behaviour and hen avoidance behaviour for Australian caged laying hens. However, this study did confirm a relationship between hen avoidance behaviour, albumen corticosterone concentration, and the duration of peak egg production.

Effects of Regulating Visitor Viewing Proximity and the Intensity of Visitor Behaviour on Little Penguin (Eudyptula minor) Behaviour and Welfare.

We examined the effects of regulating the viewing proximity of visitors and the intensity of visitor behaviour on behaviours indicative of fear and stress physiology of 15 zoo-housed little penguins (Eudyptula minor). A 2 × 2 factorial fully randomised design was used to examine the effects of regulating: 1) the viewing proximity of visitors to enclosure, 'normal viewing distance' and 'increased viewing distance' (using a physical barrier set up 2 m away from the enclosure), and 2) the intensity of visitor behaviour, 'unregulated visitor behaviour' and 'regulated visitor behaviour' (using signage and uniformed personnel). In addition, a treatment consisting of closing the enclosure to visitors was included. Penguin behaviour, visitor numbers and visitor behaviour were recorded by CCTV video recordings and direct observations, respectively. Penguin faecal glucocorticoid metabolites were also analysed as a measure of stress physiology. We found that increased viewing distance reduced (p < 0.05) all visitor behaviours except for loud vocalisations and tactile contact with penguins. However, there were no direct effects of signage and uniformed personnel on visitor behaviour (p > 0.05). As the regulation of viewing proximity increased from a closed exhibit to an open exhibit with increased viewing distance, and then to an open exhibit with normal viewing distance, this increased the proportion of penguins huddling (p = 0.0011), vigilant (p = 0.0060) and retreating (p = 0.00013), and decreased the proportion of penguins within 1 m of the visitor viewing area (p = 0.00066), surface swimming (p = 0.00091) and preening in the water (p = 0.042). There were also limited effects of regulating visitor behaviour on penguin behaviour. No treatment effects were found on faecal glucocorticoid metabolites (p > 0.05). These results indicate that regulating visitor viewing proximity affects penguin behaviours indicative of fear and visitor behaviour. This suggests that close visitor contact can be fear-provoking for little penguins but increasing the distance between visitors and penguins can reduce fear responses of penguins by regulating both viewing proximity and visitor behaviour. However, it is unclear whether these changes in penguin behaviour are due to the increased separation between visitors and penguins and/or specific visitor behaviours associated with close viewing proximity to the enclosure, such as leaning over the enclosure or tactile contact with the pool, which are impeded when visitors are further away.

Sediment Facilitates Microbial Degradation of the Herbicides Endothall Monoamine Salt and Endothall Dipotassium Salt in an Aquatic Environment.

Endothall dipotassium salt and monoamine salt are herbicide formulations used for controlling submerged aquatic macrophytes and algae in aquatic ecosystems. Microbial activity is the primary degradation pathway for endothall. To better understand what influences endothall degradation, we conducted a mesocosm experiment to (1) evaluate the effects of different water and sediment sources on degradation, and (2) determine if degradation was faster in the presence of a microbial community previously exposed to endothall. Endothall residues were determined with LC-MS at intervals to 21 days after endothall application. Two endothall isomers were detected. Isomer-1 was abundant in both endothall formulations, while isomer-2 was only abundant in the monoamine endothall formulation and was more persistent. Degradation did not occur in the absence of sediment. In the presence of sediment, degradation of isomer-1 began after a lag phase of 5⁻11 days and was almost complete by 14 days. Onset of degradation occurred 2⁻4 days sooner when the microbial population was previously exposed to endothall. We provide direct evidence that the presence and characteristics of sediment are of key importance in the degradation of endothall in an aquatic environment, and that monoamine endothall has two separate isomers that have different degradation characteristics.

Impacts of visitor number on Kangaroos housed in free-range exhibits.

Free range exhibits are becoming increasingly popular in zoos as a means to enhance interaction between visitors and animals. However very little research exists on the impacts of visitors on animal behaviour and stress in free range exhibits. We investigated the effects of visitor number on the behaviour and stress physiology of Kangaroo Island (KI) Kangaroos, Macropus fuliginosus fuliginosus, and Red Kangaroos, Macropus rufus, housed in two free range exhibits in Australian zoos. Behavioural observations were conducted on individual kangaroos at each site using instantaneous scan sampling to record activity (e.g., vigilance, foraging, resting) and distance from the visitor pathway. Individually identifiable faecal samples were collected at the end of each study day and analysed for faecal glucocorticoid metabolite (FGM) concentration. When visitor number increased, both KI Kangaroos and Red Kangaroos increased the time spent engaged in visitor-directed vigilance and KI Kangaroos also increased the time spent engaged in locomotion and decreased the time spent resting. There was no effect of visitor number on the distance kangaroos positioned themselves from the visitor pathway or FGM concentration in either species. While there are limitations in interpreting these results in terms of fear of visitors, there was no evidence of adverse effects animal welfare in these study groups based on avoidance behaviour or stress physiology under the range of visitor numbers that we studied.

Effect of partial covering of the visitor viewing area window on positioning and orientation of zoo orangutans: A preference test.

The window of the visitor viewing area adjacent to an animal platform in an orangutan enclosure was altered to produce three viewing treatments in a randomized controlled experiment. These treatments were window uncovered, left side of the window covered or right side of the window covered. Observations were conducted on the orangutans present on the platform, and on their location (left or right side), and orientation (towards or away from the window) while on the platform. The partial covering of the window had little effect on the proportion of time orangutans spent on the viewing platform, or on the direction they faced when on the platform. When the orangutans were facing towards the window, and the right side was uncovered, irrespective of whether the left side was covered, they spent about three quarters of the time on the right side, suggesting a preference for the right side of the platform. However, when the right side was covered and the left side uncovered, the animals facing towards the window spent only about a quarter of the time on the right side, that is, they spent more time on the uncovered side. The results suggest that the orangutans have a preference to position themselves to face the window of the visitor viewing area.

The Effect of Age, Stocking Density and Flooring during Transport on Welfare of Young Dairy Calves in Australia.

Transport of young ('bobby') calves for slaughter is a contentious welfare issue for some sectors of the Australian community. Factors of age, stocking density and flooring need further research to develop appropriate welfare standards for transport of bobby calves. The objective of this study was to identify the space allowance requirements for transport of bobby calves and to understand factors such as age and flooring that minimise risks to calf welfare during transport. Animals aged 3-, 5- and 10-day old were transported for 12 h in a custom-made cattle truck fitted with 9 pens, with movable mesh divisions. Each pen contained 4 calves, with space allowances of 0.2, 0.3 and 0.5 m² per calf and flooring of solid metal, mesh or straw bedding. A total of 432 male dairy calves were transported in 12 trips during the 2-year study. Behavioural measurements included lying during transport, and lying and drinking for 12 h after transport during recovery. Blood samples were taken prior to transport, immediately after transport and 12 h after transport. Blood samples were analysed for metabolic state (glucose, beta-hydroxy-butyrate (BOHB)), hydration (packed cell volume (PCV)) and exhaustion/bruising (creatine kinase (CK) activity). It was found that several measures were affected by age, which indicates that the physiology and in particular lying behaviour of 3-day old calves is fundamentally different from that of older calves. It is unclear how this affects their ability to cope with the stressors of transport. Space affected the posture changes and CK activity during and after transport and it is concluded that space allowance should be at least 0.3 m² per calf for calves of average size, while CK activity suggested that providing more space to 0.5 m² per calf may provide even greater benefits. Straw bedding is of clear benefit to calves during transport, to the extent that it may even reduce some of the negative effects of reduced space on lying behaviour.

Health beneficial long chain omega-3 fatty acid levels in Australian lamb managed under extensive finishing systems.

The variation in levels of the health claimable long chain omega-3 fatty acids, eicosapentaenoic acid (EPA, 20:5n-3) plus docosahexaenoic acid (DHA, 22:6n-3) across production regions of Australia was studied in 5726 lambs over 3 years completed in 87 slaughter groups. The median level of EPA plus DHA differed dramatically between locations and sometimes between slaughters from the same location. The ratio of EPA plus DHA from lambs with high values (97.5% quantile) to lambs with low values (2.5% quantile) also differed dramatically between locations, and between slaughters from the same location. Consistency between years, at a location, was less for the high to low value ratio of EPA plus DHA than for the median value of EPA plus DHA. To consistently obtain high levels of omega-3 fatty acids in Australian lamb, there must be a focus on lamb finishing diets which are likely to need a supply of α-linolenic acid (18:3n-3), the precursor for EPA and DHA.

Sources of variation of health claimable long chain omega-3 fatty acids in meat from Australian lamb slaughtered at similar weights.

The sources of variation of health claimable omega-3 polyunsaturated fatty acids (eicosapentaenoic acid, EPA+docosahexaenoic acid, DHA) in 2000 Australian lambs were investigated using 98 sires (Merino, maternal or terminal breeds) that were mated to about 5000 Merino or crossbred (Border Leicester×Merino) ewes. Pasture was supplemented with feedlot pellets, grains or hay as necessary, when the availability of quality green pasture was limited. Lambs were grown at 8 sites across Australia and when slaughtered the longissimus lumborum muscle was collected. Site and kills within sites were the major sources of variation for health claimable fatty acids. These environmental effects are likely to be driven by dietary background. The sire variance differed from about one twentieth to a half of the residual lamb within dam variation, depending on site and kill. This is the first comprehensive study to investigate on-farm sources of variation of long chain omega-3 polyunsaturated fatty acid content of lamb meat.

Relationship between muscle antioxidant status, forms of iron, polyunsaturated fatty acids and functionality (retail colour) of meat in lambs.

The relationship between muscle vitamin E, forms of iron, polyunsaturated fatty acids (PUFA) and the redness of meat (retail display) at days 3 to 4 post slaughter from lambs offered 2 different diets was examined. Meat redness was positively related to vitamin E and heme iron and negatively related to total n-3, total n-6 and total PUFA content. However, after adjusting for the effects of vitamin E and heme iron content, there was no indication of any residual relationship between redness at days 3-4 of retail display and total n-3, total n-6 or total PUFA. This indicates that the relationship between PUFA and redness in meat is mediated through the effects of heme iron and vitamin E in the muscle. It appears that the level of highly oxidisable PUFAs in muscle tissues do not play a major role in maintenance of redness at days 3-4 of retail display, but the level of vitamin E and heme iron content are important.

The relationships between morphological features and social signalling behaviours in juvenile dogs: the effect of early experience with dogs of different morphotypes.

Research on dog communication has tended to focus on breed differences and the use of lupine signals by the domestic dog. However, the relationship between morphological change and communication has received little empirical study. The link between morphology and behavioural selection in a canid undergoing domestication, the silver fox (Vulpes vulpes), has been well documented. Therefore, it is reasonable to propose a similar link may be present in another canid species that has undergone domestication, namely the domestic dog (Canis familiaris). Inter-morphotype interactions (587 interactions) of 115 juvenile dogs aged 8-20 weeks from over 30 breeds and various hybrids, enrolled in veterinary "Puppy Socialisation Classes", were video taped. Each signal that could be sent, was recorded, and the sending and the intended receiving dog identified. The frequencies with which a dog sent each category of signal, and the frequency with which each category of signal was directed at the dog (elicited), were calculated. The relationship between these frequencies and the morphology of the dog was then studied using generalized linear models. Overall morphology of the dog was not related to either the sending or eliciting of any social signaling behaviours (social signals). However, snout length was related to both the signals sent by a dog, and especially the signals that were directed to a dog (elicited). Relationships to eye cover and coat length were also found. Possible explanations for the results are discussed, and avenues for further research are indicated.

The relationship of adult morphology and early social signalling of the domestic dog (Canis familiaris).

Most research on dog communication has focused on either the use of lupine signals during intra-specific interactions or has studied single-breed groups, with little regard to the effects of morphological change in the dog on their communication. This oversight ignores the fact that most modern dog breeds do not resemble the wolf and thus they have lost the ability to send some signals and may encounter communication problems. Using puppies in 40 litters from 32 breeds, we investigated the relationship between the frequencies of behaviours (social signals), and the adult morphology of these dogs. Despite a high level of precision, no statistically significant relationships were found between the deviation of the adult morphology from the ancestral lupine morphotype and early social signalling in the dog. We concluded that any communication loss due to morphological deviation, is not compensated for by increasing the frequency of signalling behaviours at this age.