Aims: This study characterized biochemical compound variability that influence green bean quality in C. canephora as a basis for identifying heterogeneous genotypes for use in crop improvement because genetic erosion aided by climate change effects is gradually threatening the cultivation of Original Research Article Aluka et al.; AJEA, 12(2): 1-13, 2016; Article no.AJEA.23004 2 Ugandan Robusta coffee (Coffea canephora) local races. Study Design: Four hundred and fifty four accessions from twenty four districts were analyzed with Near Infra Red Spectroscopy (NIRS) for six biochemical compounds using calibrations developed at CIRAD, France. Place and Duration of Study: This work was conducted at the National Coffee Resources Research Institute (NaCORRI), Uganda between January 2007 and December 2013. Methodology: Spectrometer Nirsystem 6500 Foss(Denmark) machine and Software ISI NIRS 2 version 4.11 (Infra Soft International, Port Matilda, USA) were used to analyze ground samples in diffuse reflectance from 400 nm to 2500 nm (2 nm steps) and predictive models were used to quantify the biochemical contents in the green beans. Data was analyzed with XLSTAT version 2011.2.05 (Addinsoft), Paris, France. Results: Chlorogenic acid and fat concentrations of 13.26 and 13.19% dry matter respectively reported in this study, were much higher than 5.88 and 9.0% dry matter respectively reported earlier. Caffeine concentrations were positively significantly correlated with cholorogenic acid but negatively significantly correlated with trigonelline, sucrose, fat and dry matter contents. Caffeine and chlorogenic acid concentrations increased with age whereas trigonelline declined as trees aged. Chlorogenic acid and trigonelline concentrations were at their lowest levels in elevations of between 10001200 metres above sea level and like fat and dry matter concentrations, the compounds were at their highest levels in higher elevations of about 1500 metres above sea level. Local landraces, ‘’nganda’’ and ‘’erecta’’ had higher concentrations of chlorogenic acid, sucrose and caffeine than improved, hybrid and commercial types. Conclusions: Ugandan C. canephora caffeine content was lower than that of West-African Robusta coffee but higher than that of Arabica coffee. Four distinct diversity groups derived from the six biochemical compounds represented the major organoleptic categories. The results reported here will be useful in defining the desirable cup qualities of Robusta coffee as demanded by world markets.
Lambing percentage is the main contributor to higher profit on New Zealand sheep farms and has increased from 98% in 1960 to 124% in 2006. As ewe litter size increases so does the proportion of triplet-born lambs and consequently preweaning mortality rate. The purpose of this study was to investigate the effect of birthweight (BWT) on survival in triplet-born lambs within and among litters. Data from a total of 594 triplet crossbreed lambs born to mixed-age ewes was analysed. For the statistical analysis, the lambs were allocated according to their BWT, and within the litter were then allocated to three BWT groups (light, medium and heavy). The following parameters were calculated: total litter BWT (TBWT), percentage of TBWT for each lamb (PBWT = BWT/TBWT), coefficient of variation for BWT within litter and lamb average daily gain from birth to weaning. The mortality rate for the light, medium and heavy lambs was 56, 40 and 28%, respectively, and consequently the lightest lamb in a litter was 3.2 times more likely to die than the heaviest lamb. In the light lamb group, as BWT increased mortality decreased (P = 0.006), for medium lambs BWT did not influence mortality (P = 0.88) and in the heavy group there was a trend of increased BWT associated with increased mortality (P = 0.10). The negative relationship between lamb mortality and PBWT was identical in the three BWT groups (P < 0.0001). The effect of BWT on lamb mortality became non-significant when PBWT was fitted in the same model. This means that, in triplet-born lambs, mortality is not influenced by the BWT of the lamb itself, but by the BWT of its littermates. It can be calculated that a 4-kg lamb has a 24% chance of surviving in a litter of 16 kg, a 60% chance in a litter of 12 kg and an 87% chance of surviving in a litter of 8 kg. It is concluded that reducing the variation in BWT within a litter, or specifically managing the lightest lamb at birth, will increase the competitive ability for survival of each lamb and, therefore, decrease overall mortality and further improve farm profitability.
A variety of nutritional management strategies that reduce enteric methane (CH4) production are discussed. Strategies such as increasing the level of grain in the diet, inclusion of lipids and supplementation with ionophores (> 24 ppm) are most likely to be implemented by farmers because there is a high probability that they reduce CH4 emissions in addition to improving production efficiency. Improved pasture management, replacing grass silage with maize silage and using legumes hold some promise for CH4 mitigation but as yet their impact is not sufficiently documented. Several new strategies including dietary supplementation with saponins and tannins, selection of yeast cultures and use of fibre-digesting enzymes may mitigate CH4, but these still require extensive research. Most of the studies on reductions in CH4 from ruminants due to diet management are short-term and focussed only on changes in enteric emissions. Future research must examine long-term sustainability of reductions in CH4 production and impacts on the entire farm greenhouse gas budget.
The Australian Beef Industry identified variable eating quality as a major contributor to declining beef consumption in the early 1990s and committed research funding to address the problem. The major issue was the ability to predict the eating quality of cooked beef before consumption. The Meat Standards Australia (MSA) program developed a consumer testing protocol, which led to MSA grading standards being defined by consumer score outcomes. Traditional carcass grading parameters proved to be of little value in predicting consumer outcomes. Instead a broader combination of factors forms the basis of an interactive prediction model that performs well. The grading model has evolved from a fixed parameter ‘Pathway’ approach, to a computer model that predicts consumer scores for 135 ‘cut by cooking method’ combinations for each graded carcass. The body of research work conducted in evaluating critical control points and in developing the model predictions and interactions has involved several Australian research groups with strong support and involvement from the industry.
Animal production systems are large and complex sources of greenhouse gases (GHG), especially nitrous oxide (N2O) and methane (CH4). Emissions from these systems are expected to rise over the coming decades due to the increasing global population and shifting diets, unless appropriate mitigation strategies are implemented. In this paper, we argue that the main constraints for such implementation are: (i) the complex and often poorly understood controls of GHG sources in animal production systems; (ii) the lack of knowledge on the economic and social costs involved in implementing mitigation strategies; and (iii) the strong political emphasis on mitigating nitrate leaching and ammonia volatilisation, rather than GHG emissions. We further argue that overcoming these three constraints can only be achieved by initiating integrated mitigation strategies, based on modelling and experimental work at three scales. At the ‘laboratory and field scale’, basic causal relationships with respect to processes of GHG formation and other detrimental fluxes need to be experimentally established and modelled. As management options are considered at the ‘farm scale’, this is the ideal scale to evaluate the cost-effectiveness, feasibility and possible pollution swapping effects of mitigation measures. Finally, at the ‘national and supra-national scales’, environmental legislation is implemented, effectiveness of environmental policies and emissions abatement measures are being monitored, and the social costs of various scenarios are being weighed. We illustrate the need for integral measures and working across different scales using our own work on the relationship between nitrogen surplus and fluxes to the environment. At the field scale, a clear positive relation between nitrogen surplus and N2O emission, NO3– leaching and NH3 volatilisation was experimentally established. At the farm scale, the model DAIRYWISE was used to evaluate effects of minimising nitrogen surplus on the nutrient flow and economic viability of an average Dutch dairy farm. Even after including trade-off effects of CH4 emissions from cattle and manure storage, there was still a clear positive relationship between farm gate nitrogen surplus and GHG emission. At this scale, the prime issue was balancing environmental gains with economic viability. Finally, at the ‘national and supra-national scale’ we developed the MITERRA-EUROPE model, and used it to quantify the effects on GHG emissions of environmental policies aimed at reducing NO3– leaching and NH3 volatilisation in the 27 Member States of the European Union (EU-27). This showed the intricate relationship between different environmental goals, with both positive feedback (balanced fertilisation reduced both NO3– leaching and N2O emission) and negative feedback (‘low-emission’ manure application reduced NH3 volatilisation but increased N2O emission) possible. At this scale, there is a clear need for an integral approach towards reducing environmental assessment to the environment. Our studies so far suggest that ‘balanced fertilisation’ is among the most promising mitigation measures for simultaneously lowering N2O emission, NO3– leaching and NH3 volatilisation, without pollution swapping to CH4 emission.
The effects of different management practices on testicular development of young Bonsmara bulls fed a high energy (HE), medium energy (ME) and low energy (LE) diet after weaning were determined. Testicular histology and seminal traits were examined together with scrotal circumference (SC) development over an 84-day performance test trial period. The SC differed significantly (P < 0.001) between HE-, ME- and LE-fed bulls. Seminal traits, such as semen concentration were significantly (P < 0.001) lower in bulls fed the HE diet (1.3 ± 0.134) compared with those fed the ME diet (2.4 ± 0.18) and LE diet (2.6 ± 0.16). Similarly, linear movement of sperm was also affected by diet and movement was slower (P < 0.05) in bulls fed the HE diet (1.7 ± 0.30) compared with bulls fed the ME diet (2.2 ± 0.31) and LE diet (3.1 ± 0.23). The percentage total major (P < 0.001) and total minor (P < 0.05) sperm defects were also greater in the HE-fed bulls (27.1 ± 6.82 and 7.4 ± 0.91) compared with the ME-fed bulls (9.7 ± 1.45 and 5.5 ± 0.87) and for the LE-fed bulls (5.4 ± 1.26 and 3.9 ± 0.58). Dietary energy level (P < 0.05) influenced the percentage inactive seminiferous tubuli, with bulls fed the HE diet having 35% more seminiferous tubules classified as inactive compared with those bulls fed ME and LE diets. Scrotal fat deposits were higher (P < 0.05) in bulls fed the HE diet (243.4 ± 21.59 g) compared with those fed the ME (110.0 ± 12.1 g) and LE (88.4 ± 9.65 g) diets. Feeding HE diets to young bulls probably reduces their reproductive potential.
To meet the rapid and increased demand for animal protein, intensive poultry and livestock farming units are growing quickly in many developing countries in Asia. To access the markets, such production units are primarily located in peri-urban areas where available land for manure treatment and/or recycling back to the soil is limited, thus leading to serious environmental pollution. Although poultry manure from these farms is readily used as organic fertiliser for the production of cash crops, pig manure is usually washed and discharged, with or without treatment, into nearby streams and rivers. Efficient treatment of wastewater from pig farms with limited land is very expensive as it normally requires some degree of artificial aeration. Although it has long been proven that the biogas produced from the anaerobic lagoons can be converted to reusable fuel for heating and/or the generation of electricity for the farm, the technology has not been well received by farmers because they have easy access to other cheap energy sources. However, due to the opportunity of gaining extra monetary return from carbon credit trading under the initiative of the Kyoto Protocol, many pig farmers are beginning to show interest in this technology. From a recent feasibility study conducted in Malaysia to assess the technical and economic viabilities of converting biogas from pig farms into electricity, the following challenges were identified: (i) the organic content of the wastewater generated from the pig farm was far below that required for the efficient production of biogas; (ii) the high costs required for the modification of the existing farm infrastructures and additional equipment made the project economically unattractive; (iii) the potential amount of electricity generated from such a project does not match the daily fluctuating electricity demand on-farm; (iv) current governmental policies and infrastructural supports to buy back the extra electricity generated from such a project are inadequate; (v) the misconception by farmers that recovery of biogas from an anaerobic lagoon will enhance the efficiency of wastewater treatment and thus improve the quality of their wastewater at endpoint to meet the governmental requirements for discharge; and (vi) the quantum sharing of the carbon fund by farmers and the carbon credit trading company.
Thirty Black goat male kids were used in a 3 × 2 factorial arrangement to evaluate the effects of three dietary energy levels (EL) and early castration (TRT) on growth performance, body and carcass characteristics. Upon weaning at 90 days of age, kids were randomly divided into three equal groups (n = 10: five intact and five castrated) and assigned to one of the three dietary treatments containing 15% CP and different energy levels: low (LEL; 10.44 MJ ME/kg DM), medium (MEL; 11.60 MJ ME/kg DM) and high energy (HEL; 12.90 MJ ME/kg DM). Kids were individually fed on an ad libitum basis and were slaughtered at the end of the fattening period. Results showed no differences between castrated and intact kids in feed and nutrient intake. The level of dietary energy affected dry matter intake (P < 0.05), metabolisable energy intake (P < 0.01), crude protein intake (P < 0.05), neutral detergent fibre (P < 0.001) and acid detergent fibre intakes (P < 0.001). Dry matter intake was 280, 305 and 264 g/kg W0.75.day for kids receiving LEL, MEL and HEL diets, respectively. Metabolisable energy intake was the highest for kids receiving the MEL diet (0.90 Mcal/kg W0.75.day) compared with LEL (0.73 Mcal/ kg W0.75.day) and HEL (0.88 Mcal/kg W0.75.day) diets. Final liveweight and average daily gain (ADG) were greater (P < 0.01) in MEL diets. Kids fed MEL gained 133 g/day, while ADG values were 92 and 100 g/day for kids fed LEL and HEL diets, respectively. Total muscle percentage was greater (P < 0.05) for kids fed MEL diets (55.9%) compared with LEL (53.8%) and HEL (51.1%) diets. Castrated kids had lower (P < 0.01) carcass muscle percentage, but higher carcass (P < 0.01) and subcutaneous (P < 0.001) fat percentages than intact kids. It can be concluded that the best growth performance was observed in kids receiving the MEL with no differences between castrated and intact kids. Castration influenced accretion of fat in castrated kids.
The intent, in this manuscript, is to characterise the United States Department of Agriculture (USDA) and Meat Standards Australia (MSA) systems for assessing beef quality and to describe the research evidence that supports the principles involved in grade application. USDA beef quality grading standards rely on carcass-trait-only assessments of approximate age of the animal at harvest and amount of intramuscular fat (as marbling) inside the muscles. USDA beef quality grading started 82 years ago. Then, as now, because no traceability system was in place, each animal’s history (exact age, feeding regimen, management practices, etc.) was incomplete; those who assigned quality grades used indicators of age (physiological maturity) and plane of nutrition (amount of marbling), and they do so still. Since 1926, research studies have identified a multitude of palatability-determining live-animal factors (e.g. genetics, use of hormonal growth promotants, high-energy diet finishing) and carcass-treatment factors (e.g. electrical stimulation, tenderstretch carcass suspension, postmortem aging) that cannot be incorporated into a carcass-trait-only quality assessment system. The USA beef industry has depended on development of more than 100 beef brands – some using palatability assurance critical control point plans, total quality management (TQM) philosophies, USDA certification and process verification programs, or combinations of live-animal factors, carcass-treatment factors and carcass-trait constraints – to further differentiate fresh beef products. The MSA grading system is a TQM grading approach that incorporates animal-specific traits (e.g. genetics, sex, age), control of certain pre-harvest and post-harvest processes in the beef chain, cut-specific quality differences and consumer preferences, into a beef pricing system. A unique aspect of the MSA grading system is that the grades are assigned to cuts or muscles, not carcasses; cuts or muscles from the same carcass are assigned individual (and in many cases, different) grades that reflect differences in expected eating quality performance among the various cuts of beef further adjusted to reflect the influence of cut or muscle aging and alternative cooking methods. The MSA grading system is still being modified and refined (using results of an extensive, ongoing consumer testing program), but it represents the best existing example of a TQM grading approach for improving beef quality and palatability. Research studies have shown that the accuracy of palatability-level prediction by use of the two systems – USDA quality grades for US customers and consumers and MSA grades for Australian customers and consumers – is sufficient to justify their continued use for beef quality assessment.
The predominant cause of dystocia in 2-year-old heifers is feto–maternal disproportion, and consequently, birthweight of the calf explains much variation in dystocia. This experiment was carried out to identify other factors in addition to birthweight that contribute to the probability of dystocia. Seventy-three primiparous, 2-year-old Angus heifers were observed continuously during the calving period and record was made of the time at which various events occurred during parturition. Frequency of abdominal contractions was lower 30 min after onset of parturition than at 60–180 min after onset of parturition (P < 0.05). The longest stage of parturition was the time from the first abdominal contraction until the appearance of amnion, while the time from the appearance of the head until delivery of the calf was the shortest stage. Frequency of abdominal contractions was negatively correlated with duration of parturition. Duration of parturition was less than 135 min for 75% of the non-assisted heifers. Body dimensions of calves did not explain any additional variation in dystocia beyond that explained by birthweight and sex of calf and postpartum liveweight of the heifer. Calves that had an assisted birth took longer to attempt to stand, to stand and to suckle after birth than non-assisted calves. Within the non-assisted calves, there was no impact of duration of parturition on these behaviours of the newborn calf. In conclusion, body dimensions of the calf did not contribute to the probability of dystocia, but more frequent abdominal contractions contributed to a shorter duration of parturition. Behaviour of newborn calves was adversely affected by dystocia.
Data from 648 beef samples, which had been sensory tested by 720 Korean and 540 Australian consumers were used to quantify design and demographic effects on beef sensory scores. The samples were from 36 carcasses, where sides had been either hung by the Achilles tendon or hip suspended. At boning, samples from three muscles (M. triceps brachii, M. longissimus dorsi and M. semimembranosus) were prepared and cooked by either grill (25-mm-thick steaks) or Korean barbeque (BBQ, 4-mm-thick samples) methods. A Latin square design was used to allocate samples to different presentation orders to be tasted in association with different samples. For both cooking techniques each consumer tested a starter sample followed by six experimental samples, with each sample being tasted by 10 different consumers. Design (taste panel, session, order, carry-over, sample and consumer) and demographic (age class, gender, occupation, frequency of eating meat, number of adults and children living in the house, their appreciation of meat and degree of doneness and income) effects were examined separately for tenderness, juiciness, like flavour, overall liking and a composite palatability score, within the four consumer group/cooking method subclasses. For grill samples, order of presentation was significant for most sensory variables. For BBQ samples, order of presentation failed to achieve significance for Australian consumers, but was significant (P < 0.05) for Korean consumers. Carry-over effects tended to be more important for juiciness and like flavour scores than other sensory scores. Demographic effects were generally not significant (P > 0.05) for all consumer group/cooking methods. Correlations between raw scores and those adjusted for design and demographic effects ranged from 0.93 to 0.99, indicating that if the design was balanced, or nearly balanced for design effects, then further adjustment of sensory scores was not necessary. Clipping 40% of outlying consumer scores reduced the variance of the sample mean by ~30%.
Stocking rate is often the most important and manageable factor influencing the profitability and environmental sustainability of pastoral properties. Methods for determining carrying capacity, and therefore stocking rate, include subjective approaches based on land manager experience, long-term ‘benchmark’ stocking rates and techniques using computer-aided predictions of pasture growth. This paper presents a new approach for objectively calculating short-term livestock carrying capacities of pastoral properties by integrating remotely sensed ground cover assessments as a proxy for land condition. The study region was three commercial pastoral properties in the north Australian pastoral region (above 26°S). Two properties were situated in the Victoria River District of the Northern Territory and a third in the Kimberley region of Western Australia. Annual pasture growth was estimated using GRASP, a deterministic, point-based, native pasture model developed for semiarid and tropical grasslands, which was calibrated for the different land types in the study region. Carrying capacity estimates were further refined by investigating trends in landscape cover change between years using data from satellite imagery assessment. These tools have been shown to be useful for inferring land condition and pasture growth within these regions of northern Australia but had not been integrated before this study. This study developed an approach for inferring rangeland pasture condition and applying it to refine short-term carrying capacities, thus aiding decision making. The approach developed in this study is considered to be more applicable for commercial land management than currently available methods for determining carrying capacities on pastoral properties in northern Australia.
The Notch family of genes has been implicated in specifying cell fates during hair follicle morphogenesis. We examined Notch gene expression during wool follicle formation, as an understanding of genes that influence cell distributions in the developing follicle is a prerequisite for devising molecular strategies to manipulate fibre characters and follicle density. We identified transcripts for the Notch1 receptor and one of its ligands, Jagged1, in fetal sheep skin by reverse transcriptase polymerase chain reaction. The sheep-specific cDNA sequences were used as templates to produce probes to investigate the expression patterns of Notch1 and Jagged1 in developing ovine fetal skin by in situ hybridisation. Notch1 and Jagged1 were detected in the epidermis and in a subpopulation of mesenchymal cells before follicle initiation. At day 70 during follicle initiation, transcripts were also detected in cells at the tip of the epidermal plug and in dermal condensates. By day 86, Notch1 and Jagged1 were detected in the distal cells of the epidermal downgrowths and epidermis and Notch1 was no longer detected in the mesenchyme and dermal condensates. After day 96, transcripts were absent from the epidermis, but localised to differentiating outer root sheath (ORS) cells. The distributions of transcripts implicate a Notch1–Jagged1 signal pathway in the fates of prospective ORS cells. The transient appearance of Notch1 in cells at the epidermal–mesenchymal junction during early follicle morphogenesis suggests that the receptor may be responsible for the specification of a cell subpopulation committed to a prepapilla fate at initiation.
An increasing number of ewe lambs are being presented for breeding in New Zealand, resulting in more two-tooth ewes of second parity compared with the more normal first parity. The effect of this on the resulting ewe progeny is unknown but is of interest as they are potential replacement ewes. This study was designed to determine if parity of Romney two-tooth ewes had any effect on their ewe lamb progeny to 20 months of age. Two-hundred and fifty female progeny born to two-tooth dams, which had lambed as a ewe lamb (n=97), failed to conceive at ewe lamb breeding (n=79), or had not been presented for breeding as a ewe lamb (n=74), were weighed at regular intervals. The progeny also had onset of puberty and two-tooth breeding and pregnancy scanning performance measured. There were no effects of dam group on liveweight, condition score, 18- month breeding performance or pregnancy diagnosis. However, ewe lambs born to dams which failed to conceive as ewe lambs themselves were less likely ( P < 0.05) to achieve puberty. In comparison with single-born lambs, twin- born ewes were lighter ( P < 0.05) during their first year of age only. Birth rank had no effect on puberty onset or 18- month breeding performance. These findings indicate that ewe progeny born to second parity two-tooths or two-tooths, which were not presented for breeding as aewe lamb, do not differ in their productive performance and that either group are suitable as replacement ewes. However, progeny born to two-tooth dams, which failed to conceive as a ewe lamb, would be less suitable as replacement ewes in production systems where ewe lamb breeding is an integral component of the system. Further studies are required to determine if similar relationships would be observed under differing environmental conditions and with different breeds.
Under commercial conditions in Australia, lambs are often dehydrated at slaughter despite access to water at the abattoir. Dehydration results in reduced fluid content of meat, which causes liveweight and carcass weight loss. Two experiments evaluated hydration status and carcass characteristics in lambs fed increased levels of sodium chloride (salt) and/or betaine before slaughter. Both experiments were 2 × 2 factorial designs with two levels of salt added [0 and 50 g/kg dry matter (DM)] and two levels of betaine added (0 and 6.7 g/kg DM) to the diets. The treatment diets were introduced to sheep over a 7–8-day period and then fed at 1.5 kg/day for the following 7 days. In experiment 1, 96 Poll Dorset–Merino cross wether lambs (45.9 ± 0.17 kg) were fed in individual pens and in experiment 2, 204 Merino wether lambs (43.1 ± 0.35 kg) were fed in group pens. In the first experiment, water and feed were withheld from the end of the treatment feeding period until slaughter 48 h later. In the second experiment, feed and water were withheld for the first 24 h after treatment but water was available for the next 24 h immediately before slaughter. In both experiments, consumption of the high salt diet decreased urine specific gravity and osmolarity at the end of the feeding period and after 24 h without access to water. This indicates an improved hydration status at this time. However, the difference in hydration status related to feeding salt declined during the 48-h lairage period and there were no significant differences in hot carcass weight or muscle DM among groups at slaughter. It could be concluded from this result that the addition of salt has little commercial value; however, this may not be the case. The lambs in experiment 2 did not behave according to industry expectations. They all drank water in the last 24 h in lairage and none of the groups showed severe dehydration. Further research is justified to determine if the lambs fed the diets with no added salt drunk in lairage as a learned response from the lambs fed salt and, if so, whether this can be developed into a commercial strategy. Feeding betaine did not result in any changes in hydration status or carcass characteristics.
A laboratory study investigated the impact of manure management and air temperature on the gaseous emissions of ammonia (NH3), methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) from manure stored under summer and winter conditions. Trials were carried out for 10–18 days on a pilot scale and were located outside the laboratory with a standardised protocol for ambient air speed. The concentrations of N2O, CH4, and CO2 in exhaust air from the storage vessel were analysed sequentially either by infrared detection or by gas chromatography coupled with a flame ionisation detector/electron captor detector, while NH3 concentration was determined by passing the exhaust air through acid traps. The results confirm that manure composition and temperature affect emissions of CH4, N2O, CO2 and NH3. NH3 emissions, expressed as a percentage of total nitrogen present in manure, ranged from 0.1% (duck slurry) to 12% (laying hen droppings) in winter and from 0.03% (scraped farmyard cattle manure) to 13% (laying hen droppings) in summer. Whatever the manure, nitrous oxide emissions were low, less than 0.5% of the total nitrogen. Solid manure tends to produce more CO2 than CH4, while the opposite is observed with liquid manure.
This experiment aimed to investigate the impact of pregnancy nutritional treatment on ewe lamb pregnancy rate and pregnancy loss and the liveweight of resulting lambs. Two hundred and forty ewe lambs mated during a 5-day breeding period were randomly allocated to one of three nutritional regimes ('low', 'medium' and 'high'). The low (n = 80) treatment group was fed pasture to maintain liveweight during the first 100 days of pregnancy, thereafter feeding was increased to achieve a total liveweight change of 180 g/day. The medium treatment group was fed to ensure a liveweight change equivalent to 100 g/day throughout the entire pregnancy period, while the high treatment group was offered feed ab libitum.The target liveweight changes were achieved in all ewe lamb treatment groups. Fewer (P < 0.05) ewe lambs were scanned pregnant at day 50 of pregnancy and lambed in the high treatment compared with their medium counterparts. In addition, fewer (P < 0.05) low treatment ewe lambs lambed compared with the medium treatment ewe lambs. The lower numbers lambing in the low and high treatment groups were somewhat explained by greater (P < 0.05) pregnancy losses between day 50 and term. Lambs born to low treatment ewe lambs were lighter (P < 0.05) at birth (L0), L53 and L87 and had lower (P < 0.05) survival rates than those born to either medium or high treatment ewe lambs.While the present study was not designed to identify optimal ewe lamb feeding levels in pregnancy, it clearly indicates adverse effects from either a low or high level of pregnancy nutrition beginning in early pregnancy. Therefore, further studies are required to identify the optimal pastoral feeding conditions for the pregnant ewe lamb.
Estimates of genetic parameters and genetic trends for reproductive traits and for liveweight at the commencement of breeding were obtained using data from a pair-mated ostrich flock located at Oudtshoorn in South Africa. Heritability estimates were 0.17–0.18 for egg production, 0.15–0.17 for chick production and 0.35–0.37 for liveweight. Female permanent environmental effects amounted to 0.11–0.17 for egg production, 0.14–0.19 for chick production and 0.30–0.31 for liveweight. Service sire exerted significant effects only on egg production (0.03–0.08) and chick production (0.05–0.10). Genetic correlations of reproductive traits with liveweight were not different from zero. Initial selection in the flock was based on reproduction, in the sense that replacements were descended from the females with the highest uncorrected number of chicks produced during their season of hatch (Chick Production line). Animals that were hatched during the period from 1996 to 2006 were used to establish two more populations. The heaviest birds at ~16 months of age were used as replacements in the line selected for liveweight (Liveweight line). Birds selected for the Control line were of average uncorrected liveweight at ~16 months, and were descended from females that produced an average number of chicks in their season of hatch. Overall, the Liveweight line had higher breeding values than the Control line for the period from 1996 to 2006. The response seemed to be associated with screening from the larger population on breeding values for liveweight, as no cumulative genetic gains were evident since 1996. Breeding values for chick production in the Chick Production line were increased by 3.1% per year from 1990 to 2006. Regressions of individual breeding values in the Control line on the year of hatch indicated no genetic change in either liveweight or chick production. Genetic change in particularly reproduction thus seems feasible in commercial ostriches.
Genetic parameters were estimated for traits measured in the first year of production in a multi-bloodline flock of fine wool Merino sheep. Between 5025 and 9271 animals were measured, depending on the trait, and these animals were the progeny of up to 430 sires. Heritability estimates for fleece weight traits ranged from 0.37 to 0.49, while estimates for five wool quality traits ranged from 0.34 for staple strength to 0.66 for mean fibre diameter. For bodyweight, the heritability estimated at weaning was 0.20, and at the yearling age was 0.51. Maternal genetic effects were significant for fleece weight and bodyweight traits and were highly correlated between these trait groups, indicating that these effects are determined by similar groups of genes in both trait groups. While most genetic correlation estimates were either favourable or neutral, there were economically antagonistic correlations between fleece weight and mean fibre diameter, ranging from 0.15 to 0.30, and between mean fibre diameter and staple strength (0.26). Overall, the heritabilities and genetic correlations estimated in this fine wool population were similar to estimates from other strains, indicating that outcomes from selection programs will be similar across strains and that fine wool sheep can be included in across flock genetic evaluations with other strains.
A total of 36 steer carcasses (18 slaughtered in Australia and 18 slaughtered in Korea), where one side had been suspended by the hip (tenderstretch) and the other by the Achilles tendon were used to provide sensory and shear force samples from the Mm. triceps brachii, longissimus lumborum and semimembranosus. Sensory samples were cooked using grill (25 mm thick) and barbeque (BBQ, 4 mm thick) methods and served to 360 untrained Australian and 720 untrained Korean consumers. Australian consumers sensory tested grill and BBQ samples from Australian carcasses (216 samples), while Korean consumers sensory tested grill and BBQ samples from both Australian and Korean carcasses (a total of 432 samples). The three-way interaction between carcass suspension, cooking method and muscle was significant (P < 0.05) for tenderness, overall liking and a composite palatability score (MQ4), where the combination of BBQ cooking and hip suspension resulted in large increases in sensory scores for the M. semimembranosus. Variation in sensory scores and shear force are discussed in the context of possible interactions with cooking temperature. There was a significant (P < 0.05) first order interaction between consumer group and muscle for juiciness score. Consumer effects were significant (P < 0.05) for all sensory scores, being largest for juiciness (~8 sensory units), like flavour and overall liking (both ~6 sensory units) and MQ4 (~5 sensory units) scores, with the smallest effect on tenderness (~2 sensory units).
