Changing Australia's trading language has enhanced the implementation of objective carcase measurement technologies.

In 2016 an Australian project, the Advanced Livestock Measurement Technologies project (ALMTech), was initiated to accelerate the development and implementation of technologies that measure lean meat yield and eating quality. This led to the commercial testing, and implementation of a range of new technologies in the lamb, beef, and pork industries. For measuring lean meat yield %, these technologies included dual energy X-ray absorptiometry, hand-held microwave systems, and 3-D imaging systems. For measuring beef rib-eye traits and intramuscular fat %, both pre- and post-chilling technologies were developed. Post-chilling, a range of camera systems and near infrared spectrophotometers were developed. While pre-chilling, technologies included insertable needle probes, nuclear magnetic resonance, and X-ray systems. Initially these technologies were trained to predict the pre-existing traits already traded upon within industry. However, this approach was limiting because the technologies could measure attributes that were either non-existent in the trading language, were superior as calibrating standards, or more accurately reflected value than the pre-existing trait. Therefore, we introduced IMF% into the trading language for both beef and sheep meat, and carcase lean%, fat%, and bone% for sheep meat. These new technologies and the traits that they predict have delivered multiple benefits. Technology provider-companies are instilled with the confidence to commercialise due to the provision of achievable accreditation standards. Processors have the confidence to invest in these technologies and establish payment grids based upon their measurements. And lastly, it has enhanced data flow into genetic databases, industry data systems (MSA), and as feedback to producers.

Continued development of a tool to measure intramuscular fat of Australian lamb carcases in commercial situations.

Despite the importance of intramuscular fat (IMF) to eating quality, as yet no methodology has been widely adopted by the whole of industry in Australia to measure it routinely. Thus, a study was conducted to investigate the potential for a Near Infra-Red (NIR) device to predict the IMF content of the loin from spectra collected on the topside which is externally located on a hanging carcase and therefore easily accessible. To this end, NIR spectra were collected from topsides (m. semimembranosus) of 258 lamb carcases over 5 data collections and a sample of muscle was collected from the loin and the topside for IMF determination using a wet chemistry method. Subsequent Partial Least Square (PLS) models suggested the ability to predict the absolute IMF content of loins was poor (R2 = 0.28, RMSE = 1.26), yet there was a moderate ability to predict the IMF content of the topside (R2 = 0.56, RMSE = 0.82). Partial Least Square Discrimination Analysis (PLS-DA) models to classify cuts based on the IMF eating quality threshold of 4.5% yielded better predictive outcomes with accuracies of 66.7% and 76.7% for loin and topside respectively. However, further research to assess the relationship between the IMF of the loin and topside and reduce the impact of differences in overall absorbance between data collections will improve predictive outcomes.

The carcass characteristics and quality of meat from lambs grazing perennial wheat with different companion legumes (clover, serradella, lucerne) or a mineral supplement.

This study compared carcasses as well as the quality and mineral concentration of meat from lambs extensively grazing perennial wheat with clover (PW + C), serradella (PW + S), lucerne (PW + L), or a mineral salt supplement (PW + Min). A split-plot design was used, wherein 3 crossbred ewe lambs (n = 72 in total) (sub-plots) grazed each of 4 forage types (plots), that were replicated across 6 locations (blocks). The feeding study concluded after 96 d, when all the lambs were slaughtered. The left longissimus lumborum muscles (LL) were collected and wet aged for either 5 or 56 d post-mortem. Lambs grazing PW + Min were found to produce carcasses with lower dressing percentage values to those grazing the other forage types (P = 0.037). The LL of lambs grazing PW + L had the lowest crude protein values (P = 0.015). Forage type by ageing period interactions did not affect meat quality. The 56 d ageing period resulted in higher purge loss (P < 0.001) and TVB-N values (P < 0.001) and a decline in shear force (P < 0.001) compared to the 5 d ageing period. The other carcass and meat quality parameters were not affected by forage type; including hot carcass weight, pH decline parameters, eye muscle area, cooking loss, intramuscular fat, sarcomere length, colour stability, and concentrations of calcium, iron, magnesium, sodium, and zinc in the LL. These findings confirm that perennial cereal production systems, that include legume forages with contrasting protein, energy, and micronutrient profiles, can deliver comparable lamb carcasses and meat quality.

Implementation of a national monitoring programme of Campylobacter in Irish broilers to measure progress of on-farm and primary processing control measures.

BACKGROUND: Campylobacter is the most common food-borne pathogen in the European Union. In 2018, the crude incidence rate in Ireland was 63.6 per 100,000 population. Chicken is considered an important source of infection for humans. In 2015, the Campylobacter Stakeholders' Group (CSG) was established to reduce Campylobacter contamination levels in Irish broiler flocks. AIMS: This work aimed to describe the Campylobacter monitoring programme that was established by the CSG, to analyse the results of this testing between 2019 and 2022, and to assess progress. METHODS AND RESULTS: This paper describes the monitoring programme that was established by the CSG, which harmonized Campylobacter enumeration testing across all Irish broiler processors and allowed comparability of results for trend analysis. An analysis of the 2019-2022 data is presented here and compared to previous studies of Campylobacter levels in Irish broilers. An analysis of the 2019-2022 data showed a significant reduction in levels in both caeca and neck skin when the results from 2022 were compared to those from 2019 to 2020. Campylobacter spp. were detected in 37% of caecal samples from first depopulation (pre-thin) broilers and 30% of neck skin samples in 2022, with just 4% of carcases (in neck skin samples) with ≥1000 colony-forming units per gram detected in 2022. Campylobacter levels detected in Irish broilers, in the present monitoring programme were less than those reported in previous studies in both caecal and carcase samples, although not directly comparable for statistical significance because of differences in study methods. CONCLUSIONS: The cooperation between stakeholders and regulators of the Irish broiler chicken industry over the past decade has facilitated a coordinated approach to monitoring of Campylobacter levels in broilers, and implementation of control measures. This has enabled a steady reduction in the levels of Campylobacter in Irish chicken.

The effect of humate as a feed additive on feed intake, production, and carcass parameters of Angus steers.

Humate may be a valuable livestock feed additive, with potential effects on nutrient utilisation and animal performance. Thus, the aim of this study was to investigate the effect of K Humate S 100R supplementation on the feed intake, liveweight gain, and carcass parameters of Angus steers. Within individual pens, 40 weaned steers were allocated to four treatment groups (n = 10/potassium humate K Humate S100R, Omnia Specialities Australia) for 100 days. The treatment groups included Group 1, 35 g K Humate S100R/animal/day; Group 2, 70 g K Humate S100R/animal/day; Group 3, 140 g K Humate S100R/animal/day; and Control Group, which were not supplemented with K Humate S100R (0 g K Humate S100R/animal/day). Chemical and mineral composition of the feed ingredients, dry matter intake (DMI), and average daily weight gains were recorded. The steers were slaughtered as a single group at a commercial Australian abattoir. Standard measures for hot standard carcass weight, eye muscle area, fat depth and coverage, marbling, ossification, meat and fat colour, dressing percentage and loin pH values at 24-hour postmortem were recorded. It was found that the steers allocated to Group 2 had higher DMI (P = 0.003) and feed conversion ratio (FCR) (P < 0.001) compared with those allocated to Group 1 and the Control Group. The MSA marbling score was lowest for steers allocated to the Control Group (P < 0.05) and comparable for those allocated to Groups 1, 2, and 3. Together, these results demonstrate that increased levels of K Humate S100R supplementation improved the carcass quality, via an increase in MSA. However, further research is warranted on the potential effects of humates supplementation on intramuscular fat associated qualities of beef.

Effect of woodchip bedding during wet conditions on feedlot cattle productivity, behaviour and relative adrenal gland weight.

Problems associated with muddy pens have been identified as some of the most serious animal welfare issues related to outdoor feedlot beef production, but there is relatively little work examining the use of woodchip bedding for lot-fed beef cattle under conditions of cold, wet, but non-freezing winters on soil under-bases. This study examined the effects of graded levels of woodchip on the performance and behaviour of feedlot cattle housed in wet pen conditions. Bos taurus steers (n = 300; 379.1 ± 24.1 kg) were blocked by weight and breed and randomly assigned to 30 10-steer feedlot pens provided with either no woodchip bedding (Control, n = 10) manure interface only, or 15 cm depth of woodchip bedding (W15, n = 10) or 30 cm depth of woodchip bedding (W30, n = 10). The steers were housed in these treatment pens for 109 days on a feedlot ration, and the pens were irrigated so that approximately 74 mm of total precipitation (irrigation + natural rainfall) fell onto the pen surface every 30 days. Temperatures were mostly <20 °C maximum and -1 to 5 °C minimum. Steers were weighed on five occasions. Animal position and posture in pen were recorded once a week over an 8-hour day-time period. Carcase characteristics were measured, and adrenal gland weights were recorded. Providing woodchip bedding increased liveweight gain (P < 0.001) and gain:feed (G:F, P = 0.012) after day 28, increased DM intake (DMI) after day 92 (P = 0.049), and increased carcase weight (P = 0.001) and dressing percentage (P = 0.023). There was no additional benefit of W30 over W15 for liveweight gain or DMI, but the benefit of W15 for G:F was lower than that of W30 by the end of the feeding period (P = 0.012). There were no effects of bedding on other carcase quality traits. Steers in Control pens utilised the front of the pen for lying and standing more than the W15 and W30 steers (P < 0.001) suggesting the steers in the Control pens perceived the front of the pen as less aversive, potentially due to increased drainage compared to rest of the pen and proximity to feed bunk. Adrenal gland weight/kg and carcase weight tended to be higher in the Control treatment group than the W30 steers (P = 0.077). This research has demonstrated that for a 109-day feeding period in cold, wet conditions, steer performance and welfare can be improved by providing a minimum of 15 cm woodchip bedding.

Dietary high-protein distiller's dried grains with solubles can fully replace soybean meal in diets for meat quails without affecting growth performance.

1. The purpose of this study was to determine the metabolisable energy of high-protein distiller's dried grains with solubles (HP-DDGS) for meat quail (Coturnix coturnix coturnix; Experiment I) and evaluate the effects of dietary levels of HP-DDGS on animal performance, carcase characteristics, meat quality, and organ weights (Experiment II).2. In Experiment 1, 96 meat quail were distributed in a completely randomised design with two treatments (reference or test diet) and six replicates of eight birds. The experimental period consisted of 5 d adaptation, followed by 5 d total excreta collection. The experimental diets consisted of a reference (control) and a test diet formulated with 800 g/kg reference diet and 200 g/kg HP-DDGS.3. In Experiment 2, 612 meat quail were distributed in a completely randomised design fed one of six dietary levels of HP-DDGS (0, 85, 170, 255, 340, or 425 g/kg) as a replacement for soybean meal. At 42 d of age, birds were slaughtered and evaluated for carcase yield, organ weights, and meat quality.4. Apparent metabolisable energy values corrected for nitrogen retention of HP-DDGS were 12.5 and 12.3 MJ/kg for males and females, respectively.5. In the starter phase (1-21 d of age), increasing dietary HP-DDGS levels had a quadratic effect on body weight (BW) (P = 0.020) and body weight gain (BWG) (P = 0.019). The maximum BW and BWG values were estimated to be achieved with 296.0 and 296.2 g/kg dietary HP-DDGS, respectively. Overall (1-42 d of age), increasing dietary HP-DDGS levels in replacement of soybean meal did not affect animal performance, carcase yield, meat quality or organ weight in meat quail.6. It was concluded that dietary HP-DDGS can fully replace soybean meal in meat quail diets without affecting growth performance, carcase yield, meat quality or organ weight.

Succession of the microbial communities and metabolic functions in composting or deep burial processing of dead chickens.

1. This study examined the effects of composting and deep burial techniques on degradation efficiency of dead chickens. Different raw materials (crushed branches or rape straws) and disinfectants (quicklime or bleaching powder) were applied in composting and deep burial process, respectively. The whole process lasted for 90 d in both summer and winter.2. High throughput sequencing displayed that Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria and Deinococcus-Thermus were the most dominant bacterial phyla during the experiment. The relative abundance of Firmicutes dwindled gradually with prolonged composting duration, while Proteobacteria, Bacteroidetes and Deinococcus-Thermous increased gradually over time.3. The bacterial functions identified from the KEGG pathway showed that amino acid and carbohydrate metabolism were the major microbial metabolic pathways that determined final degradation efficiency. At the end of the trial, the decomposition status of chicken carcases and faecal coliforms were measured.4. The results demonstrated that the optimum decomposition effect was obtained in composting compared with other treatment groups. Low ambient temperature reduced degradation efficiency, due to restricted microbial activity. In addition, faecal coliforms were not completely removed by the deep burial process of dead chickens in winter.5. These findings provide a theoretical basis for the feasibility of composting chicken carcases instead of deep burial.

Effect of genotype and sex on carcase composition, physicochemical properties, texture and microstructure of meat from geese after four reproductive seasons.

1. The objective of this study was to compare carcase weight and composition and meat quality traits of Landes, Slovak White and Kuban geese after four reproductive seasons. A total of 42 goose carcases (seven males and seven females from each breed) were assessed.2. After four reproductive seasons, the breeds differed in eviscerated carcase weight. Slovak White geese showed more breast muscle with a cooking loss, whereas Kuban geese had a higher percentage of neck and carcase discards compared to the other breeds. The breeds differed in the chemical composition of breast and leg muscles, except for collagen in breast muscles and protein in leg muscles.3. Regardless of breed, males had heavier carcase weight and higher breast muscle, leg muscle, neck and wings and lower percentages of skin with subcutaneous fat and abdominal fat relative to body weight compared to females. Sex had a significant effect on the fat and salt content, meat lightness, most textural characteristics and endomysium thickness of breast muscle. The same differences in leg muscles for chemical composition (except for protein percentage) and lightness were recorded.4. Breed x sex interactions were significant for the proportion of leg muscle, chemical composition of breast and leg muscles (except for leg protein content), muscle fibre cross-sectional area and fibre perimeter of pectoralis major muscle.5. The results showed that the carcases and meat of the goose breeds after four reproductive seasons were suitable for consumers and meat processors, due to favourable composition, high nutritive value and good technological properties.

Growth performance of broiler chickens fed on sprouted-papaya seed based diets.

The study investigated how sprouted-papaya seed meal (SPSM) a total of affected the growth and carcase traits of broilers. Based on a completely randomized design, 390 day-old Lohmann broiler chicks were allotted to CONT (chicks provided with control diet), SEED25 (diet containing 2.5% papaya seed meal), GERM1 (diet containing 1% SPSM), GERM25 (diet containing 2.5% SPSM) and GERM5 (diet containing 5% SPSM). Body weight and feed intake of chickens were weekly recorded from 14 to 36 days of age, while birds (six birds per treatment group; 30 birds in total) were slaughtered at day 36. Feeding SPSM up to 5% did not impair (p > 0.05) broilers' growth or feed intake. At 5%, SPSM compromised (p < 0.05) feed conversion ratio (FCR) and reduced breast meat proportion. SPSM at 2.5% in diets had no (p > 0.05) detrimental effects, while papaya seed meal at the same proportion lowered (p < 0.05) final body weight, weight gain, and cumulative feed intake. Overall, SPSM may be incorporated in broiler rations up to 2.5% with no harmful effects on growth, feed intake, FCR and carcase traits of broiler chickens.

Contamination of chicken carcasses and the abattoir environment with Listeria monocytogenes in Taiwan.

1. The following study provides the first data on the detection and types of Listeria monocytogenes isolated from broiler chickens during processing and from six Taiwanese abattoir environments.2. Listeria monocytogenes was not detected in any cloacal (n = 120) or environmental (n = 256) samples collected before and during processing, indicating that faecal material and the environment of abattoirs were not important sources of L. monocytogenes for poultry carcases. However, 28 of 246 (11.4%; 95% CI: 7.7-16.0) rinse samples collected from carcases post-evisceration from three abattoirs were positive for L. monocytogenes.3. The only serotypes detected were 1/2a (82.1%; 95% CI: 63.1-93.9) and 1/2b (14.3%; 95% CI: 4.0-32.7), with 3.6% (95% CI: 0.1-18.3) non-typable isolates.4. Characterisation by Pulsed Field Gel Electrophoresis (PFGE) identified five PFGE types, confirming cross-contamination with L. monocytogenes during evisceration, chilling and post-chilling.5. These findings highlight the potential for cross-contamination to occur through direct contact between carcases, especially whilst in chilling tanks.

High levels of copper and zinc supplementation in broiler diets on growth performance, carcase traits and apparent ileal mineral absorption.

1. This study investigated the effects of hydroxy trace minerals (HTM) compared to sulphate trace minerals (STM) supplementation on growth performance, carcase parameters and mineral retention in broilers.2. A total of 1792 male Cobb 500 d-old were allocated in a completely randomised trial design to one of eight dietary treatments with eight replicates per treatment. The HTM sources used were two levels of Cu hydroxychloride (CHC) (low and high), combined with three levels of Zn hydroxychloride (ZHC) (low, med and high) and two additional treatments STM; Cu sulphate monohydrate (CSM) (low and high) combined with high Zn sulphate monohydrate (ZSM). At 21 and 42 d-old growth performance was evaluated. Additionally, at 42 d-old the carcase traits, meat quality, apparent ileal absorption and activity of antioxidant enzymes were accessed.3. A data showed that broilers receiving high-CHC had higher body weight, weight gain and better feed conversion ratio as compared to low-CHC at 21 d-old. On day 42, the feed conversion ratio was improved for birds supplemented with high-CHC in diets containing med-ZHC, as compared to low-CHC.4. Dietary Cu increased the redness of breast colour at the level of high-CHC compared to low-CHC. Greater results were observed on carcase traits for the med-ZHC group as compared to low- or high-ZHC. The ceruloplasmin activity in serum increased in the high-CSM diets containing high-ZSM as compared to low-CSM. The AIA of Cu was higher in broilers supplemented with high-CHC containing med-ZHC as compared to low-CHC. Otherwise, the AIA of Zn increased in broilers fed low-CHC containing low- or med-ZHC as compared to high-CHC.5. The trial showed that mineral trace supplementation of broilers diets with high-CHC (150 mg/kg) and low-ZHC (80 mg/kg) was a good alternative to replace sulphate mineral sources in diets.

Genetic parameters for carcase measurements and age at slaughter in commercial cattle.

Genetic parameters were estimated for cold carcase weight (CCW), carcase conformation (CON), carcase fat class (FAT), age at slaughter (AGE) and average daily carcase gain (ADCG) in 14 common UK breeds of cattle. These included crossbred animals but purebred datasets were also analysed for the most populous sire-breeds. Heritability estimates for beef breeds that were significant ranged from 0.24 to 0.44, 0.12 to 0.35, 0.12 to 0.36, 0.15 to 0.38 and 0.26 to 0.43 for CCW, CON, FAT, AGE and ADCG, respectively. For Holstein-Friesian, a dairy breed, heritability estimates were consistently lower than most beef breeds with estimates of 0.12, 0.13, 0.13, 0.06 and 0.15 for CCW, CON, FAT, AGE and ADCG, respectively. In all breed groups, genetic correlations were positive between CCW, CON and ADCG. In general, genetic correlations were moderate between CCW and CON (0.13 to 0.77), moderate to strong between CCW and ADCG (0.57 to 0.98) and weak or moderate between CON and ADCG (0.12 to 0.82). Genetic correlations for FAT with CCW (- 0.20 to - 0.42) and CON (- 0.16 to - 0.52) tended to be negative in the beef breed but were positive in the dairy breed, although not significant between CCW and FAT. For most beef breeds genetic correlations between AGE and carcase traits were not significant with the exceptions of AGE and CCW for Simmental (- 0.15) and Salers (- 0.24), AGE and CON for Limousin (0.15) and Simmental (0.14) and AGE and FAT from three sire-breeds (- 0.17 to - 0.35). However, the correlation between AGE and ADCG was negative and moderate to strong in magnitude (- 0.23 to - 0.67) in all beef breeds as expected since faster-growing animals reach slaughter age earlier. For Holstein-Friesian, all genetic correlations with AGE were negative and moderate to strong. Genetic correlations indicate that selection for increased carcase weight should simultaneously increase growth rate and improve conformation in all breeds and reduce carcase fatness in the majority of beef breeds. The results indicate that there is genetic variation in all five traits suitable for undertaking genetic improvement of carcase traits and age at slaughter; however, there are apparent breed differences. The use of abattoir-derived phenotypes for undertaking genetic improvement is an example where the supply chain can work together to share information to enable the cattle industry to move forward.

The food for feed concept. Performance of broilers fed hotel food residues.

1. In recent times the use of food waste in animal diets has gained considerable attention because of the increasing demand to cover the needs of human population and the high prices of conventional, arable based, animal feeds.2. The aim of the present study was to investigate the effect of adding dried human food waste to the diet of meat-type chickens (broilers). Two hundred, one-day-old broilers were divided into two treatment groups, with 10 replicate pens containing 10 birds per pen. The duration of the study was 42 days. In the control (C), the diet did not contain any food waste, whereas in the second treatment (T) food waste residues from hotels made up 15% of the diet. Diets had similar crude protein and metabolisable energy content.3. Feed intake and body weight were recorded in order to calculate weight gain and feed conversion ratio (FCR). Carcase and breast muscle yield, the weight of selected internal organs and the level of selected biochemical and haematological parameters were determined. Quality of breast muscle meat was assessed.4. Broilers fed the control treatment consumed more feed and gained more weight compared to broilers fed waste; however, the FCR was similar. No major differences were seen for internal organ weights and haematological parameters, although some differences were observed in colour traits and shear force of meat. It was concluded that there is a potential for use of food waste in broiler diets.

Using dual energy X-ray absorptiometry to estimate commercial cut weights at abattoir chain-speed.

This experiment assessed the ability of an on-line dual energy x-ray absorptiometer (DEXA) installed at a commercial abattoir to determine commercial cut weights in lamb carcases at abattoir chain-speed. 200 lamb carcases were scanned using a DEXA that was trained to predict the computed tomography determined proportions of fat, lean, and bone. Models were then trained using hot carcase weight and, DEXA fat% value or GR tissue depth to predict cut weight. Results from validation tests of DEXA models demonstrated excellent precision for predicting cut weight, in most cases describing more than 85% of the variation, and RMSE values that represented between 5 and 13% of the average weight of each cut. For most cuts these weight predictions were superior to those informed by GR tissue depth. This precision was maintained upon validation. Additional analyses utilised pixel information from the fore, saddle, and hind sections of DEXA images. This further enhanced the predictive power of cut weight models.

Feeding unsaleable carrots to lambs increased performance and carcass characteristics while maintaining meat quality.

This study investigated the effect of feeding unsaleable carrots to lambs within a total-mixed ration (TMR) on performance, carcass characteristics, meat quality and sensory parameters. Thirty-six Australian Merino wether lambs were fed a control (barley-based) or carrot-based TMR for 11-weeks. Carrot-fed lambs had 2.7% higher cold dressing percentage (P = 0.03) while consuming less than control lambs. Subcutaneous fat of carrot-fed lambs contained less branch-chained, and more cis- and trans-monounsaturated fatty acids (FA; P ≤ 0.01) compared to control-fed lambs, which tended (P = 0.08) to have higher concentrations of polyunsaturated FA, despite the Longissimus lumborum (LL) muscle being unchanged by diet. Under retail display conditions, L* and hue values were lower (P ≤ 0.04) for 5 d aged LL samples from carrot-fed lambs. No differences were observed in other meat quality and sensory parameters between diets. Therefore, feeding unsaleable carrots at 45% DM in a TMR can improve lamb performance and carcass characteristics, while maintaining meat quality and FA composition.

Performance and Meat Quality of Broiler Chickens Reared on two Different Litter Materials and at two Stocking Densities.

1. This study evaluated the performance and meat quality of broiler chickens reared on two litter materials and at two stocking densities.2. The chicks were allotted in a completely randomised design in a 2 × 2 factorial arrangement with two litter materials (wood shavings or rice straw) and two stocking densities (24 or 30 kg/m2), with six replicates per treatment. Broiler performance, carcase yield, prime cuts, blood plasma proteins, the enzymes alanine aminotransferase and aspartate aminotransferase, edible viscera, immune organs, intestine weight and length, abdominal fat, breast meat colour, pH, weight loss by defrosting, weight loss by cooking and shear force were evaluated.3. The density of 24 kg/m2 positively influenced feed consumption and weight gain. The type of litter had a positive influence on feed conversion, with a lower value for birds raised on wood shavings.4. Breast production was improved in birds reared at a density of 24 kg/m2 when compared to birds reared at a density of 30 kg/m2. The rice straw bedding negatively affected abdominal fat (resulting in higher percentages) when compared to birds reared on wood shavings.5. The types of litter affected the enzyme aspartate aminotransferase in birds raised on wood shavings, although these values were not increased to the point of influence on the physiological functions of broilers.6. The colour of the breast meat, pH, temperature, weight loss after thawing or cooking, shear force, cholesterol, triglycerides, albumin, total proteins, glucose or alanine aminotransferase content were not influenced by the stocking densities or bedding.7. The use of wood shavings as poultry bedding at a stocking density of 24 kg/m2resulted in the best performance for broiler chickens at 42 days of age.

Association between visual marbling score and chemical intramuscular fat with camera marbling percentage in Australian beef carcasses.

This study assessed the precision and accuracy in the prediction of chemical intramuscular fat (IMF%), Meat Standards Australia (MSA) marbling score and AUS-MEAT eye-muscle area (EMA) using Meat Imaging Japan (MIJ) prototype camera systems. Eleven carcass datasets from the Beef Information Nucleus (BIN) project were compiled with carcass grading, IMF% and camera data. Camera prediction of IMF%, MSA marbling score and EMA was assessed using a leave-one-out cross validation method. There was an association between MIJ mirror and MIJ-30 camera traits and IMF%, MSA marbling score and EMA. However, for both prototypes precision varied for IMF% (R2 = 0.4-0.5, RMSECV = 1.5-1.6%), MSA marbling (R2 = 0.3-0.5, RMSECV = 57.5-59.3) and EMA (R2 = 0.7-0.6, RMSECV = 4.1-5.8 cm2). Accuracy also fluctuated with average bias values of 1.7-1.8%, 45.8-40.0 units and 3.8-4.1 cm2 for IMF%, MSA marbling score and EMA respectively. Key differences between carcass and camera traits and processing factors affecting the grading site are likely to have contributed to this variation.

Determining the 4th limiting amino acid in low crude protein diets for male and female Cobb MV × 500 broilers.

1. Four experiments were conducted to determine the 4th limiting amino acid (AA) in maize-soybean meal-based diets. 2. Deletion assay methodology was used to quantify performance and carcase trait responses to potential deficiencies in essential and conditionally essential AA caused by reductions in dietary crude protein of maize-soybean meal-based diets from 202.9 to 186.5 g/kg. 3. The deletion of Val, Phe and Gly + Pro resulted in negative effects on live performance and carcase traits for male broilers, whereas AA deletion only affected wing weights for females with no response on live performance. 4. Further experimentation could not duplicate a response to Phe or Pro in male broilers. 5. Valine was identified as the potential 4th limiting AA in maize-soybean meal-based diets and was not found to be co-limiting with Ile.

Preliminary investigation for the prediction of intramuscular fat content of lamb in-situ using a hand- held NIR spectroscopic device.

Intramuscular fat (IMF) content is critical in the determination of eating quality. At present the Australian lamb industry has no ability to measure IMF as carcases are not split and processing speeds of up to 15 animals per minute prohibit the use of traditional methods. Consequently, the potential for a hand-held Near- Infrared (NIR) device to predict the IMF content of lamb topside in-situ was investigated. Models demonstrated that there is an ability to predict the IMF content of topside (R2 = 0.58, RMSEP = 0.85) using NIR spectra collected at 24 h post-mortem and loin (R2 = 0.50, RMSEP = 0.91). However, the models were limited by the range and distribution of the lamb population measured. Thus, further research is required to determine whether these models can be improved by increasing the range of data in the calibration models and considering alternate methods of analysis which are suitable for skewed populations.