R. Polkinghorne, R. Watson, J. Thompson, D. Pethick
Progress in the development and adoption of the Meat Standards Australia system has encouraged substantial change and an improved consumer awareness at all points of the Australian beef production chain. The system is moving from niche to mainstream market application with the exciting potential to transform many industry practices and build a more direct consumer focus. The system aims to accurately predict consumer satisfaction levels for individual cooked beef portions. This is a major advance on grading systems that classify carcasses into groups of like appearance. A prediction model was developed based on consumer testing and has proved to be useful in categorising a wide range of beef into consumer grades within cooking methods. These provide a basis to ensure a predictable eating quality result for the consumer and a mechanism to align product description and pricing throughout the production chain. When used in value-based marketing systems financial reward can be directly linked to consumer satisfaction encouraging a consumer-focussed industry. Research is proceeding to extend and improve the accuracy of the prediction model encompassing additional cattle types and cooking methods. Several projects in other countries are adding insights into the relative response of consumers from varied cultural backgrounds. It is hoped that further international collaboration will facilitate use of the developed technology to improve consumer value and industry returns through improved product consistency in global markets.
{"title":"Current usage and future development of the Meat Standards Australia (MSA) grading system","authors":"R. Polkinghorne, R. Watson, J. Thompson, D. Pethick","doi":"10.1071/EA07175","DOIUrl":"https://doi.org/10.1071/EA07175","url":null,"abstract":"Progress in the development and adoption of the Meat Standards Australia system has encouraged substantial change and an improved consumer awareness at all points of the Australian beef production chain. The system is moving from niche to mainstream market application with the exciting potential to transform many industry practices and build a more direct consumer focus. The system aims to accurately predict consumer satisfaction levels for individual cooked beef portions. This is a major advance on grading systems that classify carcasses into groups of like appearance. A prediction model was developed based on consumer testing and has proved to be useful in categorising a wide range of beef into consumer grades within cooking methods. These provide a basis to ensure a predictable eating quality result for the consumer and a mechanism to align product description and pricing throughout the production chain. When used in value-based marketing systems financial reward can be directly linked to consumer satisfaction encouraging a consumer-focussed industry. Research is proceeding to extend and improve the accuracy of the prediction model encompassing additional cattle types and cooking methods. Several projects in other countries are adding insights into the relative response of consumers from varied cultural backgrounds. It is hoped that further international collaboration will facilitate use of the developed technology to improve consumer value and industry returns through improved product consistency in global markets.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07175","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58792597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Watson, R. Polkinghorne, A. M. Gee, M. Porter, J. Thompson, D. Ferguson, D. Pethick, B. M. McIntyre
The effect of several different hormonal growth promotant (HGP) implant strategies on the palatability and carcass traits of different muscles in beef carcasses was investigated using samples from heifer and steer carcasses from a Bos indicus composite breed. In experiment 1, there were seven different implant strategies evaluated in heifers that were given different combinations of up to three implants (implanted at weaning, during backgrounding and at feedlot entry). A total of 112 heifers were slaughtered and 11 muscles or portions were collected from both sides [Mm. adductor femoris, gracilus, semimembranosus, longissimus dorsi lumborum, triceps brachii caput longum, semispinalis capitis, serratus ventralis cervicis, spinalis dorsi, biceps femoris (syn. gluteobiceps), tensor fasciae latae, gluteus medius (both the ‘D’ and the ‘eye’ portions) rectus femoris, vastus intermedius, vastus lateralis and vastus medialis]. These muscles were used to prepare a total of 1030 sensory samples which were aged for either 7 or 21 days and frozen. Thawed samples were cooked using different cooking methods (grill, roast and stir frying) before being evaluated by a consumer taste panel that scored samples for tenderness, juiciness, like flavour and overall liking. Experiment 2 used the steer portion from the same calving, which were treated to a similar array of HGP strategies, except that they were given up to four implants between weaning and slaughter at ~3 years of age. In experiment 2, there was a total of 12 different HGP implant strategies tested. At boning, three muscles (Mm. psoas major, longisimuss dorsi thoracis and lumborum portions) were collected from each of 79 carcasses with a total of 237 steak samples that consumers tested as grilled steaks. For both experiments, the mean of the HGP implant strategies resulted in increased ossification scores (P 0.05), and aging rates differed among the muscles (P 0.05).
{"title":"Effect of hormonal growth promotants on palatability and carcass traits of various muscles from steer and heifer carcasses from a Bos indicus–Bos taurus composite cross","authors":"R. Watson, R. Polkinghorne, A. M. Gee, M. Porter, J. Thompson, D. Ferguson, D. Pethick, B. M. McIntyre","doi":"10.1071/EA05112","DOIUrl":"https://doi.org/10.1071/EA05112","url":null,"abstract":"The effect of several different hormonal growth promotant (HGP) implant strategies on the palatability and carcass traits of different muscles in beef carcasses was investigated using samples from heifer and steer carcasses from a Bos indicus composite breed. In experiment 1, there were seven different implant strategies evaluated in heifers that were given different combinations of up to three implants (implanted at weaning, during backgrounding and at feedlot entry). A total of 112 heifers were slaughtered and 11 muscles or portions were collected from both sides [Mm. adductor femoris, gracilus, semimembranosus, longissimus dorsi lumborum, triceps brachii caput longum, semispinalis capitis, serratus ventralis cervicis, spinalis dorsi, biceps femoris (syn. gluteobiceps), tensor fasciae latae, gluteus medius (both the ‘D’ and the ‘eye’ portions) rectus femoris, vastus intermedius, vastus lateralis and vastus medialis]. These muscles were used to prepare a total of 1030 sensory samples which were aged for either 7 or 21 days and frozen. Thawed samples were cooked using different cooking methods (grill, roast and stir frying) before being evaluated by a consumer taste panel that scored samples for tenderness, juiciness, like flavour and overall liking. Experiment 2 used the steer portion from the same calving, which were treated to a similar array of HGP strategies, except that they were given up to four implants between weaning and slaughter at ~3 years of age. In experiment 2, there was a total of 12 different HGP implant strategies tested. At boning, three muscles (Mm. psoas major, longisimuss dorsi thoracis and lumborum portions) were collected from each of 79 carcasses with a total of 237 steak samples that consumers tested as grilled steaks. For both experiments, the mean of the HGP implant strategies resulted in increased ossification scores (P 0.05), and aging rates differed among the muscles (P 0.05).","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA05112","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58773288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Polkinghorne, J. Philpott, A. Gee, A. Doljanin, J. Innes
A major trial was conducted to develop, test and demonstrate the application of Meat Standards Australia (MSA) research findings in a beef retailing environment. A new concept retail store was established whereby a mix of raw beef products and pre-cooked meals were merchandised under an eating quality grade defined by MSA palatability scores. Products were presented fully prepared within cooking method with pricing based on the predicted cooked results. Large price differentials were established between the three grades offered, with 5-star product priced at more than double the 3-star product. The principle of pricing being directly related to eating quality was extended from the retail store sales to fabrication and the purchase of source cattle from producers. This encouraged considerable innovation to optimise eating quality and returns, demonstrating the potential for truly transparent value-based pricing systems to achieve change. Novel systems were developed to break down and fabricate the carcass into ‘retail-ready’ product with extensive software development to trace the eating quality, value and location of individual cuts and products. Detailed feedback provided the producer with an accurate measure of value and sufficient data to evaluate possible alternative production strategies. Results at each level of the supply chain were encouraging with compound annual growth in sales exceeding 12% at retail level and continued innovation through fabrication and on-farm areas combining to improve eating quality and financial outcomes. It was demonstrated that the consumer focus delivered by MSA grades could be applied at a commercial level providing an opportunity to reposition beef as a contemporary consumer product and to implement a value-based system across all sectors.
{"title":"Development of a commercial system to apply the Meat Standards Australia grading model to optimise the return on eating quality in a beef supply chain","authors":"R. Polkinghorne, J. Philpott, A. Gee, A. Doljanin, J. Innes","doi":"10.1071/EA05181","DOIUrl":"https://doi.org/10.1071/EA05181","url":null,"abstract":"A major trial was conducted to develop, test and demonstrate the application of Meat Standards Australia (MSA) research findings in a beef retailing environment. A new concept retail store was established whereby a mix of raw beef products and pre-cooked meals were merchandised under an eating quality grade defined by MSA palatability scores. Products were presented fully prepared within cooking method with pricing based on the predicted cooked results. Large price differentials were established between the three grades offered, with 5-star product priced at more than double the 3-star product. The principle of pricing being directly related to eating quality was extended from the retail store sales to fabrication and the purchase of source cattle from producers. This encouraged considerable innovation to optimise eating quality and returns, demonstrating the potential for truly transparent value-based pricing systems to achieve change. Novel systems were developed to break down and fabricate the carcass into ‘retail-ready’ product with extensive software development to trace the eating quality, value and location of individual cuts and products. Detailed feedback provided the producer with an accurate measure of value and sufficient data to evaluate possible alternative production strategies. Results at each level of the supply chain were encouraging with compound annual growth in sales exceeding 12% at retail level and continued innovation through fabrication and on-farm areas combining to improve eating quality and financial outcomes. It was demonstrated that the consumer focus delivered by MSA grades could be applied at a commercial level providing an opportunity to reposition beef as a contemporary consumer product and to implement a value-based system across all sectors.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA05181","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58774322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meat Standards Australia sought a consistent measure of the beef eating experience to the consumer. Rather than objective measurements or trained panel sensory assessment, it was decided to proceed with direct consumer assessment. Consumer-based assessment has much greater variation, but it has the decided advantage of validity. This paper summarises the path taken to obtain consistent consumer assessment. What meat samples to present to consumers? What responses to ask for? What to do with these responses when they were obtained? The answers to these questions have led to the MQ4 measure of consumer assessment of meat eating quality, which now forms the basis of the MSA predictive model.
{"title":"Consumer assessment of eating quality – development of protocols for Meat Standards Australia (MSA) testing","authors":"R. Watson, A. Gee, R. Polkinghorne, M. Porter","doi":"10.1071/EA07176","DOIUrl":"https://doi.org/10.1071/EA07176","url":null,"abstract":"Meat Standards Australia sought a consistent measure of the beef eating experience to the consumer. Rather than objective measurements or trained panel sensory assessment, it was decided to proceed with direct consumer assessment. Consumer-based assessment has much greater variation, but it has the decided advantage of validity. This paper summarises the path taken to obtain consistent consumer assessment. What meat samples to present to consumers? What responses to ask for? What to do with these responses when they were obtained? The answers to these questions have led to the MQ4 measure of consumer assessment of meat eating quality, which now forms the basis of the MSA predictive model.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07176","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58792721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evidence is presented that suggests strongly that hormone growth promotant (HGP) implantation has a negative effect on beef palatability. This is based on a meta-analysis of results reported in refereed papers that have appeared in the meat-science literature. To be included in this analysis, a paper must have reported results for control samples (no HGP) and treatment samples (HGP) for either objective testing (Warner-Bratzler shear-force) or consumer preference (tenderness score). The paper must also have reported estimates and standard errors. Further, we consider only the case of steers, and the M. longissimus dorsi (striploin). While most of these studies yielded non-significant differences, most gave an estimate indicating that the HGP treatment had a negative effect on beef palatability. When these results are combined using a meta-analysis, they provide significant evidence that the use of HGP implants negatively influences palatability.
{"title":"Meta-analysis of the published effects of HGP use on beef palatability in steers as measured by objective and sensory testing","authors":"R. Watson","doi":"10.1071/EA07174","DOIUrl":"https://doi.org/10.1071/EA07174","url":null,"abstract":"Evidence is presented that suggests strongly that hormone growth promotant (HGP) implantation has a negative effect on beef palatability. This is based on a meta-analysis of results reported in refereed papers that have appeared in the meat-science literature. To be included in this analysis, a paper must have reported results for control samples (no HGP) and treatment samples (HGP) for either objective testing (Warner-Bratzler shear-force) or consumer preference (tenderness score). The paper must also have reported estimates and standard errors. Further, we consider only the case of steers, and the M. longissimus dorsi (striploin). While most of these studies yielded non-significant differences, most gave an estimate indicating that the HGP treatment had a negative effect on beef palatability. When these results are combined using a meta-analysis, they provide significant evidence that the use of HGP implants negatively influences palatability.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07174","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58792437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Hwang, R. Polkinghorne, Jong-Moon Lee, J. Thompson
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 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%.
{"title":"Demographic and design effects on beef sensory scores given by Korean and Australian consumers","authors":"I. Hwang, R. Polkinghorne, Jong-Moon Lee, J. Thompson","doi":"10.1071/EA05113","DOIUrl":"https://doi.org/10.1071/EA05113","url":null,"abstract":"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 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%.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA05113","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58773504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Y. Park, I. Hwang, S. H. Cho, Y. Yoo, J. Kim, Jong-Moon Lee, R. Polkinghorne, J. Thompson
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).
{"title":"Effect of carcass suspension and cooking method on the palatability of three beef muscles as assessed by Korean and Australian consumers","authors":"B. Y. Park, I. Hwang, S. H. Cho, Y. Yoo, J. Kim, Jong-Moon Lee, R. Polkinghorne, J. Thompson","doi":"10.1071/EA07189","DOIUrl":"https://doi.org/10.1071/EA07189","url":null,"abstract":"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).","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07189","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58793283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Thompson, R. Polkinghorne, M. Porter, H. Burrow, R. A. Hunter, G. Mccrabb, R. Watson
The effect of repeated implantation with 20mg oestradiol-17b (Compudose 100) on carcass and meat quality traits was investigated using 478Bos indicusandB. indicus ·Bos tauruscross steers finished on either pasture or grain to achieve carcass weight for one of three market end points (domestic, 220kg; Korean, 280kg; or Japanese, 340kg). In the oestradiol-17b treatment group, animals were administered implants at ~100-day intervals, with the number of implants administered to any steer ranging from one to eight. Cattle were slaughtered and at boning the anterior portion of the M. longissimus lumborum was removed and frozen after aging for 1 day for later objective meat quality measurements (shear force, compression and cook loss %). The adjoining portion was aged for 14 days before consumer sensory testing using the Meat Standards Australia protocols. Each sample was scored for tenderness, juiciness, like flavour and overall liking by 10 untrained consumers. Implanting increased carcass weights and ossification scores (P 0.05) on sensory scores, or objective meat tenderness.
{"title":"Effect of repeated implants of oestradiol-17b on beef palatability in Brahman and Braham cross steers finished to different market end points","authors":"J. Thompson, R. Polkinghorne, M. Porter, H. Burrow, R. A. Hunter, G. Mccrabb, R. Watson","doi":"10.1071/EA08193","DOIUrl":"https://doi.org/10.1071/EA08193","url":null,"abstract":"The effect of repeated implantation with 20mg oestradiol-17b (Compudose 100) on carcass and meat quality traits was investigated using 478Bos indicusandB. indicus ·Bos tauruscross steers finished on either pasture or grain to achieve carcass weight for one of three market end points (domestic, 220kg; Korean, 280kg; or Japanese, 340kg). In the oestradiol-17b treatment group, animals were administered implants at ~100-day intervals, with the number of implants administered to any steer ranging from one to eight. Cattle were slaughtered and at boning the anterior portion of the M. longissimus lumborum was removed and frozen after aging for 1 day for later objective meat quality measurements (shear force, compression and cook loss %). The adjoining portion was aged for 14 days before consumer sensory testing using the Meat Standards Australia protocols. Each sample was scored for tenderness, juiciness, like flavour and overall liking by 10 untrained consumers. Implanting increased carcass weights and ossification scores (P 0.05) on sensory scores, or objective meat tenderness.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08193","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58807494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laboratory and free-ranging studies on the emu, ostrich and kiwi show ratites to be competent homeotherms. While body temperature and basal metabolic rate are lower in ratites than other birds, all of the thermoregulatory adaptations present in other birds are well established in ratites. The thermoneutral zone has been established for the emu and kiwi, and extends to 10°C. Below that zone, homeothermy is achieved via the efficient use of insulation and elevated metabolic heat production. In the heat, emus and ostriches increase respiratory evaporative water loss and use some cutaneous water loss. Respiratory alkalosis is avoided by reducing tidal volume. In severe heat, tidal volume increases, but the emu becomes hypoxic and hypocapnic, probably by altering blood flow to the parabronchi, resulting in ventilation/perfusion inhomogeneities. Ostriches are capable of uncoupling brain temperature from arterial blood temperature, a phenomenon termed selective brain cooling. This mechanism may modulate evaporative effector responses by manipulating hypothalamic temperature, as in mammals. The implications of thermal physiology for ratite production systems include elevated metabolic costs for homeothermy at low ambient temperature. However, the emu and ostrich are well adapted to high environmental temperatures.
{"title":"Thermoregulation in ratites: a review","authors":"S. Maloney","doi":"10.1071/EA08142","DOIUrl":"https://doi.org/10.1071/EA08142","url":null,"abstract":"Laboratory and free-ranging studies on the emu, ostrich and kiwi show ratites to be competent homeotherms. While body temperature and basal metabolic rate are lower in ratites than other birds, all of the thermoregulatory adaptations present in other birds are well established in ratites. The thermoneutral zone has been established for the emu and kiwi, and extends to 10°C. Below that zone, homeothermy is achieved via the efficient use of insulation and elevated metabolic heat production. In the heat, emus and ostriches increase respiratory evaporative water loss and use some cutaneous water loss. Respiratory alkalosis is avoided by reducing tidal volume. In severe heat, tidal volume increases, but the emu becomes hypoxic and hypocapnic, probably by altering blood flow to the parabronchi, resulting in ventilation/perfusion inhomogeneities. Ostriches are capable of uncoupling brain temperature from arterial blood temperature, a phenomenon termed selective brain cooling. This mechanism may modulate evaporative effector responses by manipulating hypothalamic temperature, as in mammals. The implications of thermal physiology for ratite production systems include elevated metabolic costs for homeothermy at low ambient temperature. However, the emu and ostrich are well adapted to high environmental temperatures.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08142","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58805923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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.
{"title":"Direct responses in breeding values to selection of ostriches for liveweight and reproduction","authors":"S. Cloete, Z. Brand, K. Bunter, I. Malecki","doi":"10.1071/EA08124","DOIUrl":"https://doi.org/10.1071/EA08124","url":null,"abstract":"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.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58805285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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