This paper reviews opportunities to improve the diet quality, intake and performance of animals through manipulation of the partial preference commonly shown by grazing animals for different pasture components. Using evidence from the well-worked example of grass–legume pastures, potential opportunities to manipulate preference are highlighted, including: (i) altering plant characteristics to change the relative preference of alternative species or cultivars; (ii) utilising variation in preference among and within animal species; and (iii) working with, rather than against, known preference patterns, by offering forages as spatially separated monocultures within the same paddock or at different times of the day. In all cases, it is argued that is important to consider the full complexities of pasture–animal interactions, in particular, how current diet choices feed back to determine choices available subsequently in the pasture. To develop feeding systems where desirable pasture traits for animal performance are sustained at a high abundance in the diet, plant and animal breeding selection practises and grazing management systems should take greater account of the existence of partial preferences.
{"title":"Manipulating dietary preference to improve animal performance","authors":"G. Edwards, A. Parsons, R. Bryant","doi":"10.1071/EA08006","DOIUrl":"https://doi.org/10.1071/EA08006","url":null,"abstract":"This paper reviews opportunities to improve the diet quality, intake and performance of animals through manipulation of the partial preference commonly shown by grazing animals for different pasture components. Using evidence from the well-worked example of grass–legume pastures, potential opportunities to manipulate preference are highlighted, including: (i) altering plant characteristics to change the relative preference of alternative species or cultivars; (ii) utilising variation in preference among and within animal species; and (iii) working with, rather than against, known preference patterns, by offering forages as spatially separated monocultures within the same paddock or at different times of the day. In all cases, it is argued that is important to consider the full complexities of pasture–animal interactions, in particular, how current diet choices feed back to determine choices available subsequently in the pasture. To develop feeding systems where desirable pasture traits for animal performance are sustained at a high abundance in the diet, plant and animal breeding selection practises and grazing management systems should take greater account of the existence of partial preferences.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58800485","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. Cassar-Malek, B. Picard, C. Bernard, J. Hocquette
In the context of sustainable agriculture and animal husbandry, understanding animal physiology remains a major challenge in the breeding and production of livestock, especially to develop animal farming systems that respond to the new and diversified consumer demand. Physiological processes depend on the expression of many genes acting in concert. Considerable effort has been expended in recent years on examining the mechanisms controlling gene expression and their regulation by biological and external factors (e.g. genetic determinants, nutritional factors, and animal management). Two main strategies have been developed to identify important genes. The first one has focussed on the expression of candidate genes for key physiological pathways at the level of both the transcripts and proteins. An original strategy has emerged with the advent of genomics that addresses the same issues through the examination of the molecular signatures of all genes and proteins using high-throughput techniques (e.g. transcriptomics and proteomics). In this review, the application of the gene expression studies in livestock production systems is discussed. Some practical examples of genomics applied to livestock production systems (e.g. to optimise animal nutrition, meat quality or animal management) are presented, and their outcomes are considered. In the future, integration of the knowledge gained from these studies will finally result in optimising livestock production systems through detection of desirable animals and their integration into accurate breeding programs or innovative management systems.
{"title":"Application of gene expression studies in livestock production systems: a European perspective","authors":"I. Cassar-Malek, B. Picard, C. Bernard, J. Hocquette","doi":"10.1071/EA08018","DOIUrl":"https://doi.org/10.1071/EA08018","url":null,"abstract":"In the context of sustainable agriculture and animal husbandry, understanding animal physiology remains a major challenge in the breeding and production of livestock, especially to develop animal farming systems that respond to the new and diversified consumer demand. Physiological processes depend on the expression of many genes acting in concert. Considerable effort has been expended in recent years on examining the mechanisms controlling gene expression and their regulation by biological and external factors (e.g. genetic determinants, nutritional factors, and animal management). Two main strategies have been developed to identify important genes. The first one has focussed on the expression of candidate genes for key physiological pathways at the level of both the transcripts and proteins. An original strategy has emerged with the advent of genomics that addresses the same issues through the examination of the molecular signatures of all genes and proteins using high-throughput techniques (e.g. transcriptomics and proteomics). In this review, the application of the gene expression studies in livestock production systems is discussed. Some practical examples of genomics applied to livestock production systems (e.g. to optimise animal nutrition, meat quality or animal management) are presented, and their outcomes are considered. In the future, integration of the knowledge gained from these studies will finally result in optimising livestock production systems through detection of desirable animals and their integration into accurate breeding programs or innovative management systems.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58800739","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}
Paull, I. Colditz, Caroline Lee, S. Atkinson, A. Fisher
In this study, we examined the potential of several widely used non-steroidal anti-inflammatory drugs (NSAIDs) and other analgesics to reduce pain and stress in sheep after surgery. Because mulesing involves a greater degree of tissue trauma than other surgical husbandry procedures such as castration or tail-docking, it provides a more rigorous and conservative test to identify potentially useful analgesic strategies in sheep. Merino lambs (5 weeks of age) were randomised into eight treatment groups: (1) carprofen; (2) flunixin; (3) ketoprofen; (4) buprenorphine; (5) xylazine; (6) lignocaine epidural; (7) saline control; (8) sham control. The NSAIDs were administered 1.5 h before mulesing, buprenorphine 0.75 h and xylazine and lignocaine 0.25 h before mulesing. Pain- and discomfort-related behaviours were recorded for 12 h after mulesing, and plasma cortisol concentrations were measured before mulesing and 0.5, 6, 12, 24 and 48 h after mulesing. The results indicated that no single analgesic treatment provided satisfactory analgesia during both the surgical mulesing procedure and the ensuing period of pain associated with the inflammatory phase. However, there were indications that two NSAIDs (carprofen and flunixin) showed good potential as analgesics during the inflammatory phase. A combination of short- and long-acting analgesics may be needed to provide more complete pain relief. In conclusion, the administration of some NSAIDs offers the potential for good analgesia in sheep for the inflammatory phase following the tissue trauma of surgical husbandry procedures. Other analgesic options need to be considered if the acute stress response to the procedure is to be reduced.
{"title":"Effectiveness of non-steroidal anti-inflammatory drugs and epidural anaesthesia in reducing the pain and stress responses to a surgical husbandry procedure (mulesing) in sheep","authors":"Paull, I. Colditz, Caroline Lee, S. Atkinson, A. Fisher","doi":"10.1071/EA08050","DOIUrl":"https://doi.org/10.1071/EA08050","url":null,"abstract":"In this study, we examined the potential of several widely used non-steroidal anti-inflammatory drugs (NSAIDs) and other analgesics to reduce pain and stress in sheep after surgery. Because mulesing involves a greater degree of tissue trauma than other surgical husbandry procedures such as castration or tail-docking, it provides a more rigorous and conservative test to identify potentially useful analgesic strategies in sheep. Merino lambs (5 weeks of age) were randomised into eight treatment groups: (1) carprofen; (2) flunixin; (3) ketoprofen; (4) buprenorphine; (5) xylazine; (6) lignocaine epidural; (7) saline control; (8) sham control. The NSAIDs were administered 1.5 h before mulesing, buprenorphine 0.75 h and xylazine and lignocaine 0.25 h before mulesing. Pain- and discomfort-related behaviours were recorded for 12 h after mulesing, and plasma cortisol concentrations were measured before mulesing and 0.5, 6, 12, 24 and 48 h after mulesing. The results indicated that no single analgesic treatment provided satisfactory analgesia during both the surgical mulesing procedure and the ensuing period of pain associated with the inflammatory phase. However, there were indications that two NSAIDs (carprofen and flunixin) showed good potential as analgesics during the inflammatory phase. A combination of short- and long-acting analgesics may be needed to provide more complete pain relief. In conclusion, the administration of some NSAIDs offers the potential for good analgesia in sheep for the inflammatory phase following the tissue trauma of surgical husbandry procedures. Other analgesic options need to be considered if the acute stress response to the procedure is to be reduced.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58803115","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}
The aim of this study was to monitor the metabolic profile and oxidative status in goats during the peripartum period. A blood sample was taken from 10 Red Syrian goats on days −21, −3, +1, +14, and +28 from delivery. Samples were assayed for glutathione peroxidase and superoxide dismutase activities, and reactive oxygen metabolites, insulin, insulin-like growth factor-I, free triiodothyronine (fT3), free thyroxine (fT4), leptin, urea, non-esterified fatty acids, triglycerides, cholesterol, total protein, albumin, globulin, calcium and inorganic phosphorus concentrations. Blood glutathione peroxidase activity decreased during the postpartum period and its values were significantly (P < 0.05) lower on days 14 and 28 postpartum. Albumin levels were significantly (P < 0.05) lower on days −3, 1 and 28 from delivery compared with day −21. Plasma urea levels significantly (P < 0.001) decreased starting from day −3 from delivery. No effect of time from delivery was noted on reactive oxygen metabolites, non-esterified fatty acids, triglycerides, cholesterol, total protein, calcium and inorganic phosphorus, insulin and leptin concentrations and superoxide dismutase activity. Plasma concentrations of fT3 were significantly (P < 0.01) higher on days 14 and 28 compared with days −21, −3 and 1 from delivery. Plasma levels of fT4 were significantly (P < 0.01) lower on days −3 and 1 from delivery. Plasma insulin-like growth factor-I values slowly decreased during the postpartum period and its values were significantly (P < 0.05) lower on day 28. This study indicates that goats experienced moderate oxidative stress during the peripartum period.
{"title":"Metabolic profile and oxidative status in goats during the peripartum period","authors":"P. Celi, A. Trana, A. Quaranta","doi":"10.1071/EA07410","DOIUrl":"https://doi.org/10.1071/EA07410","url":null,"abstract":"The aim of this study was to monitor the metabolic profile and oxidative status in goats during the peripartum period. A blood sample was taken from 10 Red Syrian goats on days −21, −3, +1, +14, and +28 from delivery. Samples were assayed for glutathione peroxidase and superoxide dismutase activities, and reactive oxygen metabolites, insulin, insulin-like growth factor-I, free triiodothyronine (fT3), free thyroxine (fT4), leptin, urea, non-esterified fatty acids, triglycerides, cholesterol, total protein, albumin, globulin, calcium and inorganic phosphorus concentrations. Blood glutathione peroxidase activity decreased during the postpartum period and its values were significantly (P < 0.05) lower on days 14 and 28 postpartum. Albumin levels were significantly (P < 0.05) lower on days −3, 1 and 28 from delivery compared with day −21. Plasma urea levels significantly (P < 0.001) decreased starting from day −3 from delivery. No effect of time from delivery was noted on reactive oxygen metabolites, non-esterified fatty acids, triglycerides, cholesterol, total protein, calcium and inorganic phosphorus, insulin and leptin concentrations and superoxide dismutase activity. Plasma concentrations of fT3 were significantly (P < 0.01) higher on days 14 and 28 compared with days −21, −3 and 1 from delivery. Plasma levels of fT4 were significantly (P < 0.01) lower on days −3 and 1 from delivery. Plasma insulin-like growth factor-I values slowly decreased during the postpartum period and its values were significantly (P < 0.05) lower on day 28. This study indicates that goats experienced moderate oxidative stress during the peripartum period.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07410","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58798800","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}
Metagenomics techniques applied to the rumen microbiota have demonstrated tremendous diversity originally among populations of bacteria and, more recently, among the methanogenic archaea, including those associated with protozoa. Although with some potential limitations, cluster analyses of sequences recovered from clone libraries have revealed differences in populations among animals fed forage v. grain, including amylolytic ruminococci and novel groups of clostridia adhering to the rumen particulates. Rapid profiling procedures, such as denaturing gradient gel electrophoresis (DGGE), can be used to infer likely differences in community structure of bacteria and archaea among numerous replicates of animals and times after feeding diets that are more representative of intense ruminant animal production. Metagenomics procedures also are being applied to issues related to ruminal output of fatty acid isomers influencing milk fat composition and consumer acceptance, the environmental impact of nitrogen in animal waste and methane emissions, and future potential approaches to improve ruminal fibre digestibility. If varying concentrations of ruminal metabolites and fluxes quantified from microbial processes can be combined with results from metagenomics applied to rumen microbiota, then we should reduce the unexplained variability in models in which the prediction of nutrient supply to the intestine is synchronised with nutritional guidelines for more efficient feed conversion by ruminants.
{"title":"Linking rumen function to animal response by application of metagenomics techniques","authors":"J. Firkins, S. Karnati, Zhongtang Yu","doi":"10.1071/EA08028","DOIUrl":"https://doi.org/10.1071/EA08028","url":null,"abstract":"Metagenomics techniques applied to the rumen microbiota have demonstrated tremendous diversity originally among populations of bacteria and, more recently, among the methanogenic archaea, including those associated with protozoa. Although with some potential limitations, cluster analyses of sequences recovered from clone libraries have revealed differences in populations among animals fed forage v. grain, including amylolytic ruminococci and novel groups of clostridia adhering to the rumen particulates. Rapid profiling procedures, such as denaturing gradient gel electrophoresis (DGGE), can be used to infer likely differences in community structure of bacteria and archaea among numerous replicates of animals and times after feeding diets that are more representative of intense ruminant animal production. Metagenomics procedures also are being applied to issues related to ruminal output of fatty acid isomers influencing milk fat composition and consumer acceptance, the environmental impact of nitrogen in animal waste and methane emissions, and future potential approaches to improve ruminal fibre digestibility. If varying concentrations of ruminal metabolites and fluxes quantified from microbial processes can be combined with results from metagenomics applied to rumen microbiota, then we should reduce the unexplained variability in models in which the prediction of nutrient supply to the intestine is synchronised with nutritional guidelines for more efficient feed conversion by ruminants.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58802184","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. Jelantik, M. Mullik, C. L. Leo-Penu, J. Jeremias, R. Copland
An on-farm experiment was conducted in several villages in the district of Kupang, East Nusa Tenggara Province (NTT), Indonesia from June to October 2007. The experiment investigated the efficacy of a supplementation strategy to improve calf survival and performance during the dry season. A total of 258 Bali (Banteng, Bos javanicus) cow-calf pairs were used in the experiment. Calves from the 190 cow-calf pairs in the treatment groups were allocated grass hay + concentrate supplementation as follows: 1% (n = 98), 2% (n = 56) and 3% (n = 42) of calf bodyweight. There were 62 cow-calf pairs in the unsupplemented control group. The supplement consisted of grass hay and concentrate (rice bran, cornmeal, leucaena leaf and fish meal) containing 18% crude protein. The supplement was introduced to calves in the morning while confined to calf pens when the dams were grazing. Calves were reunited with the cows during the night. Parameters measured were calf mortality, calf and cow daily gain, and milk production. Supplementation tended to reduce calf mortality (P = 0.094) from 6.4% in control to 0% in calves receiving 2% and 3% supplement. Levels of supplementation significantly (P < 0.001) improved calf daily weight gain. Bodyweight changes and milk production of cows were unaffected by calf supplementation. It can be concluded that supplementation at 2% calf bodyweight reduces calf mortality and improves calf weight gain.
{"title":"Improving calf survival and performance by supplementation in Bali cattle","authors":"I. Jelantik, M. Mullik, C. L. Leo-Penu, J. Jeremias, R. Copland","doi":"10.1071/EA08038","DOIUrl":"https://doi.org/10.1071/EA08038","url":null,"abstract":"An on-farm experiment was conducted in several villages in the district of Kupang, East Nusa Tenggara Province (NTT), Indonesia from June to October 2007. The experiment investigated the efficacy of a supplementation strategy to improve calf survival and performance during the dry season. A total of 258 Bali (Banteng, Bos javanicus) cow-calf pairs were used in the experiment. Calves from the 190 cow-calf pairs in the treatment groups were allocated grass hay + concentrate supplementation as follows: 1% (n = 98), 2% (n = 56) and 3% (n = 42) of calf bodyweight. There were 62 cow-calf pairs in the unsupplemented control group. The supplement consisted of grass hay and concentrate (rice bran, cornmeal, leucaena leaf and fish meal) containing 18% crude protein. The supplement was introduced to calves in the morning while confined to calf pens when the dams were grazing. Calves were reunited with the cows during the night. Parameters measured were calf mortality, calf and cow daily gain, and milk production. Supplementation tended to reduce calf mortality (P = 0.094) from 6.4% in control to 0% in calves receiving 2% and 3% supplement. Levels of supplementation significantly (P < 0.001) improved calf daily weight gain. Bodyweight changes and milk production of cows were unaffected by calf supplementation. It can be concluded that supplementation at 2% calf bodyweight reduces calf mortality and improves calf weight gain.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08038","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58802914","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}
Methane emissions from ruminant livestock represent a loss of carbon during feed conversion, which has implications for both animal productivity and the environment because this gas is considered to be one of the more potent forms of greenhouses gases contributing to global warming. Many strategies to reduce emissions are targeting the methanogens that inhabit the rumen, but such an approach can only be successful if it targets all the major groups of ruminant methanogens. Therefore, a thorough knowledge of the diversity of these microbes in different breeds of cattle and sheep, as well as in response to different diets, is required. A study was undertaken using the molecular techniques denaturing gradient gel electrophoresis, DNA cloning and DNA sequence analysis to define the extent of diversity among methanogens in ruminants, particularly Bos indicus cross cattle, on differing forages in Queensland. It was found that the diversity of methanogens in forage-fed cattle in Queensland was greater than in grain-fed cattle but there was little variability in methanogen community composition between cattle fed different forages. The species that dominate the rumen microbial communities of B. indicus cross cattle are from the genus Methanobrevibacter, although rumen-fluid inoculated digestors fed Leucaena leucocephala leaf were populated with Methanosphaera-like strains, with the Methanobrevibacter-like strains displaced. If ruminant methane emissions are to be reduced, then antimethanogen bioactives that target both broad groups of ruminant methanogens are most likely to be needed, and as a part of an integrated suite of approaches that redirect rumen fermentation towards other more useful end products.
{"title":"Diversity of methanogens in ruminants in Queensland","authors":"D. Ouwerkerk, A. F. Turner, A. Klieve","doi":"10.1071/EA08049","DOIUrl":"https://doi.org/10.1071/EA08049","url":null,"abstract":"Methane emissions from ruminant livestock represent a loss of carbon during feed conversion, which has implications for both animal productivity and the environment because this gas is considered to be one of the more potent forms of greenhouses gases contributing to global warming. Many strategies to reduce emissions are targeting the methanogens that inhabit the rumen, but such an approach can only be successful if it targets all the major groups of ruminant methanogens. Therefore, a thorough knowledge of the diversity of these microbes in different breeds of cattle and sheep, as well as in response to different diets, is required. A study was undertaken using the molecular techniques denaturing gradient gel electrophoresis, DNA cloning and DNA sequence analysis to define the extent of diversity among methanogens in ruminants, particularly Bos indicus cross cattle, on differing forages in Queensland. It was found that the diversity of methanogens in forage-fed cattle in Queensland was greater than in grain-fed cattle but there was little variability in methanogen community composition between cattle fed different forages. The species that dominate the rumen microbial communities of B. indicus cross cattle are from the genus Methanobrevibacter, although rumen-fluid inoculated digestors fed Leucaena leucocephala leaf were populated with Methanosphaera-like strains, with the Methanobrevibacter-like strains displaced. If ruminant methane emissions are to be reduced, then antimethanogen bioactives that target both broad groups of ruminant methanogens are most likely to be needed, and as a part of an integrated suite of approaches that redirect rumen fermentation towards other more useful end products.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA08049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58803026","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}
L. Bell, M. Robertson, D. Revell, J. Lilley, A. Moore
Improving the feed-base to better balance livestock demands with the variation in feed supply can improve the sustainability and productivity of livestock enterprises. This paper outlines some approaches and tools that can be applied to the assessment of new feed options and/or potential changes to the feed-base in mixed farming systems. Demonstrations of strategic aspects of designing feed systems include: whole-farm feed planning using simple tools, such as the MLA Feed Demand Calculator, that enable iterative changes to the balance between feed supply and demand to be considered simultaneously; assessing production and environmental risks of different feed-base systems using simulation models (e.g. APSIM, GRAZPLAN); and using bio-economic models (e.g. MIDAS) to investigate the impact of a new feed source on whole-farm profitability and the optimal balance of other feed sources and livestock production system. Also included is an example of an approach to identifying opportunities and seasonal triggers for a tactical response for utilising an alternate feed source (e.g. grazing a grain crop). The importance of economics and risk as factors for assessing feed-base systems is demonstrated. In particular, the marginal value of extra feed supply is a critical element driving the whole-farm economics of the feed system. Some approaches consider seasonal averages, but the risk of year-to-year and within-year variations in the timing and amount of feed supply should also be assessed. Several tools of varying complexity exist to investigate attributes of the feed-base, but it is important that the correct approach is applied to the particular question in mind. A range of approaches could be applied concurrently to fully explore a range of aspects of the performance of a feed-base system.
{"title":"Approaches for assessing some attributes of feed-base systems in mixed farming enterprises","authors":"L. Bell, M. Robertson, D. Revell, J. Lilley, A. Moore","doi":"10.1071/EA07421","DOIUrl":"https://doi.org/10.1071/EA07421","url":null,"abstract":"Improving the feed-base to better balance livestock demands with the variation in feed supply can improve the sustainability and productivity of livestock enterprises. This paper outlines some approaches and tools that can be applied to the assessment of new feed options and/or potential changes to the feed-base in mixed farming systems. Demonstrations of strategic aspects of designing feed systems include: whole-farm feed planning using simple tools, such as the MLA Feed Demand Calculator, that enable iterative changes to the balance between feed supply and demand to be considered simultaneously; assessing production and environmental risks of different feed-base systems using simulation models (e.g. APSIM, GRAZPLAN); and using bio-economic models (e.g. MIDAS) to investigate the impact of a new feed source on whole-farm profitability and the optimal balance of other feed sources and livestock production system. Also included is an example of an approach to identifying opportunities and seasonal triggers for a tactical response for utilising an alternate feed source (e.g. grazing a grain crop). The importance of economics and risk as factors for assessing feed-base systems is demonstrated. In particular, the marginal value of extra feed supply is a critical element driving the whole-farm economics of the feed system. Some approaches consider seasonal averages, but the risk of year-to-year and within-year variations in the timing and amount of feed supply should also be assessed. Several tools of varying complexity exist to investigate attributes of the feed-base, but it is important that the correct approach is applied to the particular question in mind. A range of approaches could be applied concurrently to fully explore a range of aspects of the performance of a feed-base system.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07421","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58799966","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}
The experimental objective was to determine the effect of adding whole cottonseed (WCS) to a forage and cereal grain diet on the energy and nitrogen balance and rumen function of lactating dairy cattle. Two experiments were carried out, a field experiment and an indoor metabolism experiment. In the field experiment, 50 lactating cows ~200 days in milk were randomly allocated to one of two groups (control or WCS). Cows were offered lucerne hay (morning) and ryegrass-based pasture silage (afternoon) in one group for 5 weeks. The hay and silage were placed on the ground in a bare paddock. Cows in each group were also individually offered cracked grain in a feed trough at 3 kg dry matter (DM)/cow.day at milking times. In addition, at milking times, cows in the WCS group were individually offered 2.7 kg DM/cow.day of WCS with their grain supplement. Samples of rumen fluid were collected from each fistula, ~4 h after grain feeding in the morning, of eight cows (four per group) on 1 day in each of the 5 weeks of treatment. In the metabolism experiment, immediately after the 5 weeks of feeding, 12 lactating cows, six from each treatment from the field experiment, were randomly selected and individually housed in metabolism stalls and fed the same diets for a 6-day energy and nitrogen balance study. Cows were fed at milking times (0700 and 1530 hours) and all feed offered and refused was weighed daily. All cows were offered 5.6 kg DM/cow.day of pasture silage, 4 kg DM/cow.day of lucerne hay and 3 kg DM/cow.day of cereal grain. In addition, cows in the WCS treatment group were offered 2.7 kg DM/cow.day of WCS with their grain supplement. In the metabolism study, adding WCS to the diet resulted in a greater energy intake, but there was no depression in energy digestibility. Whole cottonseed also increased nitrogen intake and nitrogen digestibility of the diet was increased from 62 to 75%, but the proportion of nitrogen in milk remained the same with a greater proportion of nitrogen appearing in body tissue. In the field experiment, supplementation with WCS did not alter rumen fluid ammonia-N or volatile fatty acid concentrations. Adding WCS did not affect three of the main classes of protozoa, based on size, within the two major orders of ciliate protozoa. The WCS did, however, reduce the levels of entodiniomorphs >200 µm diameter and holotrichs < 200 µm diameter, but these only account for a small number of the total protozoa present. Supplementation of a forage and grain-based diet with WCS improved the energy and protein content of the diet without any negative effects on rumen digestion and with a similar proportion of dietary energy and nitrogen appearing in milk. Over the summer period in winter-rainfall dairying areas in south-east Australia when pasture availability is limited and the diet is mainly comprised of forage and cereal grain fed at a level that is energy-limiting for maximum production, WCS can be and is used to supplement the diet to imp
本试验旨在研究饲粮和谷物饲粮中添加全棉籽对泌乳奶牛能量氮平衡及瘤胃功能的影响。进行了田间试验和室内代谢试验。田间试验选用50头泌乳~200日龄奶牛，随机分为对照组和WCS组。每组饲喂紫花苜蓿干草(上午)和黑麦草类牧草青贮(下午)，连续饲喂5周。干草和青贮饲料放在光秃秃的围场的地上。每组奶牛分别饲喂干物质(DM)为3 kg /头的碎粒饲料。每天挤奶的时候。此外，在挤奶时，WCS组奶牛每头单独饲喂2.7 kg干物质。在WCS中添加谷物。8头奶牛(每组4头)在5周的治疗中，每组1天，于晨饲后4 h从每个瘘管处采集瘤胃液。代谢试验中，在饲喂5周后，随机选取12头泌乳奶牛，每组6头，单独饲养于代谢栏内，饲喂相同的饲粮，进行为期6 d的能量氮平衡试验。在挤奶时间(0700和1530小时)饲喂奶牛，每天称重所有供饲和拒绝的饲料。每头奶牛饲喂5.6 kg DM。日牧草青贮，每头牛4 kg DM。每头牛饲喂3 kg干草料。谷物的日子。WCS处理组每头奶牛饲喂2.7 kg干物质。在WCS中添加谷物。在代谢研究中，饲粮中添加WCS会增加能量摄入，但不会降低能量消化率。全棉籽也提高了饲粮氮消化率，使饲粮氮消化率从62%提高到75%，但牛奶中氮的比例保持不变，身体组织中氮的比例更高。在田间试验中，添加WCS对瘤胃液氨氮和挥发性脂肪酸浓度没有影响。在纤毛虫原生动物的两个主要目中，根据大小，添加WCS对三个主要类别的原生动物没有影响。然而，WCS确实降低了直径小于200µm的内二胚和直径小于200µm的holotrichs的水平，但这些只占总原生动物的一小部分。在饲料和谷物基础饲粮中添加WCS可提高饲粮的能量和蛋白质含量，但对瘤胃消化没有负面影响，且牛奶中出现的饲粮能量和氮的比例相似。在澳大利亚东南部冬季降雨奶牛区的夏季，牧草供应有限，饲粮主要由饲料和谷物组成，饲料的能量水平限制了最大产量，WCS可以而且已经用于补充饲粮，以提高产奶量和盈利能力。
{"title":"Effect of whole cottonseed supplementation on energy and nitrogen partitioning and rumen function in dairy cattle on a forage and cereal grain diet","authors":"C. Grainger, T. Clarke, R. Eckard","doi":"10.1071/EA07400","DOIUrl":"https://doi.org/10.1071/EA07400","url":null,"abstract":"The experimental objective was to determine the effect of adding whole cottonseed (WCS) to a forage and cereal grain diet on the energy and nitrogen balance and rumen function of lactating dairy cattle. Two experiments were carried out, a field experiment and an indoor metabolism experiment. In the field experiment, 50 lactating cows ~200 days in milk were randomly allocated to one of two groups (control or WCS). Cows were offered lucerne hay (morning) and ryegrass-based pasture silage (afternoon) in one group for 5 weeks. The hay and silage were placed on the ground in a bare paddock. Cows in each group were also individually offered cracked grain in a feed trough at 3 kg dry matter (DM)/cow.day at milking times. In addition, at milking times, cows in the WCS group were individually offered 2.7 kg DM/cow.day of WCS with their grain supplement. Samples of rumen fluid were collected from each fistula, ~4 h after grain feeding in the morning, of eight cows (four per group) on 1 day in each of the 5 weeks of treatment. In the metabolism experiment, immediately after the 5 weeks of feeding, 12 lactating cows, six from each treatment from the field experiment, were randomly selected and individually housed in metabolism stalls and fed the same diets for a 6-day energy and nitrogen balance study. Cows were fed at milking times (0700 and 1530 hours) and all feed offered and refused was weighed daily. All cows were offered 5.6 kg DM/cow.day of pasture silage, 4 kg DM/cow.day of lucerne hay and 3 kg DM/cow.day of cereal grain. In addition, cows in the WCS treatment group were offered 2.7 kg DM/cow.day of WCS with their grain supplement. In the metabolism study, adding WCS to the diet resulted in a greater energy intake, but there was no depression in energy digestibility. Whole cottonseed also increased nitrogen intake and nitrogen digestibility of the diet was increased from 62 to 75%, but the proportion of nitrogen in milk remained the same with a greater proportion of nitrogen appearing in body tissue. In the field experiment, supplementation with WCS did not alter rumen fluid ammonia-N or volatile fatty acid concentrations. Adding WCS did not affect three of the main classes of protozoa, based on size, within the two major orders of ciliate protozoa. The WCS did, however, reduce the levels of entodiniomorphs >200 µm diameter and holotrichs < 200 µm diameter, but these only account for a small number of the total protozoa present. Supplementation of a forage and grain-based diet with WCS improved the energy and protein content of the diet without any negative effects on rumen digestion and with a similar proportion of dietary energy and nitrogen appearing in milk. Over the summer period in winter-rainfall dairying areas in south-east Australia when pasture availability is limited and the diet is mainly comprised of forage and cereal grain fed at a level that is energy-limiting for maximum production, WCS can be and is used to supplement the diet to imp","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07400","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58798480","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}
S. Hatcher, J. Eppleston, R. Graham, J. Mcdonald, S. Schlunke, B. Watt, K. Thornberry
Two monitoring projects were conducted to investigate weaner mortality in commercial Merino flocks in the Yass and the Central Tablelands Rural Lands Protection Boards located in the Southern Tablelands agricultural region of New South Wales. The projects were conducted in Yass in 2005 and in the Central Tablelands in 2006. A random sample of weaners from four flocks in the Yass board and 11 flocks in the Central Tablelands board were regularly weighed, growth rates were calculated after weaning and survival was determined by the continuing presence of an individual weaner at subsequent weighing activities. Weaning weight was the most important factor in determining postweaning liveweight, growth rates and survival with the significant impact of weaning weight on liveweight persisting for up to 6 months after weaning. Despite the lightest weaners being capable of considerable compensatory growth given sufficient postweaning nutrition, the lightest 25% of weaners were more than twice as likely to die as heavier weaners. A focus on ewe nutrition and parasite control during late pregnancy and lactation will allow Merino producers to achieve higher weaning weights that will set their weaners up for strong postweaning growth with a decreased likelihood of mortality.
{"title":"Higher weaning weight improves postweaning growth and survival in young Merino sheep","authors":"S. Hatcher, J. Eppleston, R. Graham, J. Mcdonald, S. Schlunke, B. Watt, K. Thornberry","doi":"10.1071/EA07407","DOIUrl":"https://doi.org/10.1071/EA07407","url":null,"abstract":"Two monitoring projects were conducted to investigate weaner mortality in commercial Merino flocks in the Yass and the Central Tablelands Rural Lands Protection Boards located in the Southern Tablelands agricultural region of New South Wales. The projects were conducted in Yass in 2005 and in the Central Tablelands in 2006. A random sample of weaners from four flocks in the Yass board and 11 flocks in the Central Tablelands board were regularly weighed, growth rates were calculated after weaning and survival was determined by the continuing presence of an individual weaner at subsequent weighing activities. Weaning weight was the most important factor in determining postweaning liveweight, growth rates and survival with the significant impact of weaning weight on liveweight persisting for up to 6 months after weaning. Despite the lightest weaners being capable of considerable compensatory growth given sufficient postweaning nutrition, the lightest 25% of weaners were more than twice as likely to die as heavier weaners. A focus on ewe nutrition and parasite control during late pregnancy and lactation will allow Merino producers to achieve higher weaning weights that will set their weaners up for strong postweaning growth with a decreased likelihood of mortality.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2008-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58799014","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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