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Beef and dairy cattle commonly ingest soil when consuming forage-based diets in paddock feeding situations. However, the extent of this soil intake is poorly understood in the Australian environment and under Australian grazing systems. Therefore, the aim of the current literature review was to examine soil ingestion in cattle and the factors that affect ingestion. We found 11 studies containing soil-ingestion data, based in England, France, New Zealand and USA but none from Australia. A wide range in soil ingestion rates was reported and intake varied considerably with season, forage-pasture type, pasture-on-offer, stocking rate and grazing conditions. Generally, soil ingestion was lower in beef cattle than in dairy cattle. We considered the differences in reported levels, variables around those differences, and reliability of methodology used, and compared results with existing international guidelines. For Australian applications, we deduced and recommended that 0.5 kg/head.day is used until field-based research is conducted in Australia which might provide a more specific value for Australian conditions. Our review will inform future livestock management, particularly on contaminated agricultural land. In Australia, there is a poor understanding of how much soil cattle ingest while grazing. We conducted a literature review and found 11 papers to inform our views, but there were no published papers from Australia. Ingestion levels varied among countries, and between dairy and beef enterprises. We estimated that cattle ingest about 0.5 kg/head.day; however, this varies according to circumstance. Research is required in Australian environment to better inform managers. [ABSTRACT FROM AUTHOR]

Livestock management and meat production involve a series of steps that affect meat quality. Animal genetics, nutrition and diets, slaughter procedures and meat-preservation conditions are some of the parameters that should be controlled to maintain meat quality. In regard to animal nutrition and diets, novel ingredients are increasingly used, distillers grains (DG) being an example. DG are obtained as a co-product from bioethanol production and comprise the fat, protein, fibre and micronutrient portion of the grains. Many papers have studied the inclusion of DG in finishing diets and their effect on growth performance and meat characteristics, but a review on the effects on meat quality is needed. Feeding with DG influences beef colour; nevertheless, a relationship between the level of inclusion and colour development has not been established yet. In addition, feeding DG-inclusion diets sometimes increases meat discoloration during retail display. Also, the composition of fatty acids is modified since total polyunsaturated fatty acid content in meat increases with the inclusion of DG in finishing diets. This increment in polyunsaturated fatty acid content is likely to contribute to lipid oxidation processes and might be related to meat discoloration due to myoglobin oxidation. However, meat tenderness has not been modified in most of the cases. This review focused on recent studies on DG inclusion, animal performance and meat quality. Key points that need further research are also identified and discussed. Meat is an important source of protein, lipids, vitamin and other nutrients for the human diet. Byproducts generated after bioethanol production used for animal feeding have effects on the beef quality, such as nutritional properties, colour and tenderness. The study of the mechanisms involved and their implications will allow to better understand the effect of the inclusion of these byproducts on the final quality of meat. [ABSTRACT FROM AUTHOR]

Context: The performance of commercial beef-breeding herds in northern Australia is highly variable. Identifying and understanding the major factors that influence this is critical in determining which management interventions should be implemented to best manage these factors. Aims: This study aimed to describe the occurrence and magnitude of the risk factors identified as being strongly associated with one or more measures of cow performance in northern Australia. Methods: A prospective epidemiological study was conducted in a cross-section of commercial beef-breeding herds in northern Australia, to determine and quantify the major associations of up to 83 candidate herd management, nutritional and environmental risk factors with cow performance. Descriptive analyses of significant risk factors were conducted. Key results: Unfavourable levels of risk factors were observed for all country types and across three cow-age groups. However, generally, adverse property-level nutritional, environmental and management risk factors had a higher incidence in the Northern Forest, which was associated with significantly lower performance of heifers and cows. This was reflected in generally lower body condition of heifers and cows in this country type. Although the performance of heifers and cows was generally higher in the Southern Forest, the irregular incidence of adverse risk factors contributed to the observed quite variable performance. Conclusions: The factors significantly affecting the performance of cows in the major beef-breeding regions of northern Australia are described. These factors were additively more adverse in the Northern Forest. Implications: In this study, the necessary understanding of the factors most likely to be affecting the performance beef cows in this environment has been described. This is required to make appropriate decisions about management interventions to control these factors. A large epidemiological study known as the Cash Cow project was conducted in commercial beef breeding herds across northern Australia between 2007 and 2011, with the aim of determining and quantifying the effect of management, nutritional and environmental factors on cow performance. This paper describes the occurrence and magnitude of the factors shown to significantly affect cow performance. [ABSTRACT FROM AUTHOR]

The present paper focuses on the economic evaluation of the observed differences in maternal productivity of different genetic lines in Angus cattle that were managed under contrasting nutritional regimes typical of southern Australia. Five hundred Angus cows were managed concurrently at two locations in southern Australia. On each site, the cows were managed under the following two different nutritional treatments: High and Low, to simulate different stocking rates. Cows selected for a divergence in either carcass rib-fat depth or residual feed intake based on mid-parent estimated breeding values for those traits, were allocated in replicate groups to either High- or Low-nutrition treatments. By design, the supplementary feeding regime was the same for the High and Low genetic lines to ensure genetic differences were not confounded with management differences. Animal productivity results from the experiment were used as input data to evaluate the economic performance of the four genetic lines under the two nutritional treatments. Two methods were used; the first was a gross-margin calculation of income minus variable costs as AU$ per breeding cow for a 1000-cow herd; the second was a whole-farm linear programming model maximising the gross margin. Stocking rates were optimised by matching the energy requirements for the whole herd with the energy available from pasture and supplementary feed on a representative 700-ha farm. Using the two methods of calculating gross margin (per cow and optimised per hectare), including examination of sensitivity to changes in prices of cattle and supplementary feed, the present study demonstrated that genetically leaner cows due to selection of low fat or low residual feed intake, had gross margins superior to those of genetically fatter cows. They generated more income by selling more liveweight due to heavier weights and higher stocking rates. The results are affected by the management system utilised and some confounding with growth (leaner genetic lines had higher growth estimated breeding values), but will assist producers to make more informed decisions about how to manage animal breeding and nutritional interactions. [ABSTRACT FROM AUTHOR]

This paper determined the impact of gender and feeding intensity on the profile of fatty acids in different types of fat deposits. The studies were conducted with 20 young bulls and 20 steers, which were Polish Holstein-Friesian and Hereford crossbreds fattened intensively - grass silage ad libitum and concentrate covered 50% of the net energy requirement in fattened cattle or semi-intensively - concentrate covered 30% of the net energy. The fatty acid profile in intramuscular, intermuscular, external and internal fat was determined. The content of intramuscular fat was lower (P < 0.001) in the longissimus muscle in the bulls (1.74%) than in the steers (3.71%). In fat of steers, the proportion of monounsaturated fatty acids was higher whereas in fat of bulls, the content of polyunsaturated fatty acids was higher. Generally the impact of the location of fat depots on the profile of fatty acids was statistically significant (P < 0.001) but there was no effect of feeding intensity. [ABSTRACT FROM AUTHOR]

Context. This study assesses the monetary value of product quality information, specifically feedback from slaughter and production methods, within the Australian beef and sheep meat supply chains. Aims. The primary objective was to investigate the value assigned by supply chain actors to product quality information, measured as willingness to pay for receiving it or willingness to accept payment for providing it. The study also aimed to explore how the value of this information varies based on information quality and quantity. Methods. A contingent valuation approach was employed, utilising survey data from 104 producers. Logit models were used to identify the factors influencing meat producers' willingness to accept payment and willingness to pay. Key results. Over one-third of cattle and sheep producers expressed interest in receiving feedback from slaughter information and providing production methods information. Production methods information had the highest mean value at the premium information quality and quantity level, with values of AU$20.49/head in the beef industry and AU$10.13/head in the sheep industry. Conversely, feedback from slaughter information had the lowest mean value at the low information quality and quantity level, with values of AU$0.83/carcass in beef and AU$0.14/carcass in sheep. Farmers' experience and education level significantly influenced their willingness to accept payment and willingness to pay for product quality information. Conclusions. A significant proportion of producers within the Australian beef and sheep meat supply chains express a desire to provide or pay for product quality information. The value assigned to this information demonstrates a positive relationship with higher information quality and quantity. However, variations in expressed value of different information types, and the influence of farmer and farm characteristics, suggest the presence of chain failures that disrupt information valuation. Implications. These findings have important implications for improving the performance of the red meat supply chains. Understanding the factors that influence the valuation of product quality information allows stakeholders to develop targeted strategies to enhance the efficiency and effectiveness of information exchange. This may involve addressing chain failures, and implementing measures to ensure consistent and accurate valuation of information. Ultimately, these improvements can contribute to enhanced decisionmaking processes and overall supply chain performance in the Australian beef and sheep meat industry. [ABSTRACT FROM AUTHOR]

Context. Although beef consumption has been linked to increased blood cholesterol, it has positive impacts on human health and provides essential nutrients of high biological value. Aims. This study investigated the effects of aging time on beef quality, the chemical composition of the Longissimus thoracis (LT) muscle, and the metabolite and fatty acid profile of the subcutaneous fat from young bulls finished in feedlot with a high-lipid diet. Methods. Fifty young bulls were divided into groups following their breed composition, Nellore (n = 25) and Angus × Nellore crossbred (n = 25), and randomly assigned into four pens. The feedlot phase consisted of 105 days of feed, and the diet (80% concentrate) was formulated to meet or safely exceed the requirements of beef cattle to achieve an average daily gain of 1.6 kg/day. After slaughter, meat samples were collected between the 11th and 13th ribs 24 h postmortem. Steaks were aged for 1, 14, 28, and 42 days. Key results. No differences were observed for total weight loss, drip loss, and cooking loss between the genetic groups (P > 0.05). An increase in lipid oxidation was observed for TBARS in the LT beef and subcutaneous fat (P < 0.01). Shear force was influenced by breed and aging time (P < 0.01). There was a significant interaction between aging time and the parameters L* a*, b* c*, and h* (P < 0.01). The crossbred animals had greater (P < 0.01) concentrations of collagen, and Nellore had greater (P < 0.01) concentration of moisture in their LT beef. In total, 33 metabolites were identified in beef extract, and differences were observed in beef from both groups. Nellore animals had higher concentrations of polyunsaturated fatty acids and conjugated linoleic acid. Conclusions. The shear force, collagen concentration, and moisture were affected by breeds, while the aging time affected lipid oxidation, shear force, and colour parameters. Different breeds and a high-lipid diet modified the metabolite profile of meat and the profile of subcutaneous fat. Implications. These findings suggest that genetic manipulation could potentially be used to improve beef quality. [ABSTRACT FROM AUTHOR]

Context: Reducing livestock emissions, the largest single contributor to agricultural emissions, is increasingly recognised as a high priority. The low biological efficiency of beef cattle, due to their long gestation period, long generational interval, and propensity to be uniparous, contributes to the high methane emissions intensity (kg CO2-e/kg product) of beef compared to most other food products. Aims: We evaluate the potential of increasing the frequency of multiparous births (twinning) as a pathway to reducing the methane intensity of beef and the net methane emissions of intensive beef systems. Methods: We simulate a uniparous herd structure and emissions profile using GrassGro™ livestock systems modelling software and then calculate the effects of an increasing frequency of multiparous births (twinning), up to 1.53 calves per cow joined, on methane emissions. Key results: Our results demonstrate that beef from calves reared as twins has a 22% lower methane intensity than beef from a single reared calf. Although twinning reduces the methane intensity of beef, at the herd level, net methane emissions could rise by as much as 23% at 1.53 calves per cow joined if overall herd size is allowed to grow through an increased number of calves. If we decrease stocking rates, whilst also increasing twinning rates, it is possible to reduce net emissions by up to 14%, without changing productivity. Conclusions: Our results illustrate the significant potential of twinning to decrease the methane intensity of beef and to increase the productivity per cow in intensive beef systems. Implications: Despite this, twinning is unlikely to be a viable net emissions reduction pathway – as twinning will increase stocking rate unless herd structure is altered – unless a commercial or policy driver to reduce net methane emissions is established. Beef has a high emissions intensity due in part to the low reproductive rate of cattle. We evaluated if increasing the rate of twinning offers a pathway to reducing the methane intensity of beef by increasing biological efficiency, our results show that beef from twin reared calves has a 22% lower methane intensity. However, twinning is unlikely to be a viable net emissions reduction pathway unless a commercial or policy driver to reduce net methane emissions is established. [ABSTRACT FROM AUTHOR]

Context. Climate and economic changes promote the encroachment of woody plants on marginal mountain pastures. In the Alps, the main woody invader is the nitrogen-fixing shrub Alnus viridis (green alder). Robust breeds of different ruminant species may perform well on these shrub-encroached pastures. Aims. To assess the effects of A. viridis encroachment levels of mountain pastures on the growth performance and carcass and meat characteristics of cattle and sheep. Methods. For 8-9 weeks, 22 15-month-old growing Dexter cattle and 20 7-month-old weaned Engadine sheep were grazed rotationally on pastures in a subalpine zone with four different levels of A. viridis encroachment (average: 0.8%, 28.7%, 50.3% and 67.8%). Following slaughter, the assessed carcass and meat characteristics (longissimus thoracis and biceps femoris) included physico-chemical meat quality, muscle fibre typing, fatty acid profiling (intramuscular and perirenal fat) and the sensory properties of patties. Key results. The shrub encroachment levels had only minor effects on the animals. Interactions with the animal species influenced some sensory and fatty acid characteristics. The average daily gains were 201 g in the Dexter cattle and 104 g in the Engadine sheep. Both species achieved satisfactory carcass and meat quality and favourably low n-6/n-3 fatty acid ratios (0.63 and 0.68 in the intramuscular fat of the cattle and sheep, respectively). The meat from the Dexter cattle had a slightly higher cooking loss and shear force and a slightly lower proportion of fatty acids relevant to human health. Flavour appreciation was in favour of the burgers prepared from the beef. Conclusions. Both robust breeds were suitable for producing meat on extensive pastures with A. viridis encroachment of up to 70%. Based on indirect evidence, it seems that neither species consumed significant quantities of leaves or bark from the trees. Implications. Our study provides detailed information on rare robust breeds of two animal species in the context of meat production according to customer preferences. To better explain the differences between the two animal species, particularly in terms of fatty acid profiles, the role of the A. viridis understory needs to be clarified. [ABSTRACT FROM AUTHOR]

Context: Fat colour is one of the most important economic traits in the marketing of beef. There are many factors that affect fat colour, such as breed, age, diet and gender. Fat colour is observed in different ranges of colours, including white, yellow and brown. The main issue with improving fat colour is that consumer preferences of fat colour vary across the globe. Therefore, investigating the metabolic mechanisms of fat colour may provide new biomarkers for phenotyping, so as to develop effective selection strategies to achieve the locally desired fat colour. Aims: This study aimed to perform a comparative metabolic analysis between white and yellow fat from crossbred cattle so as to identify potential biomarkers for the selection of fat colour and to better understand the metabolism of white and yellow fat depots. Methods: Carcass samples of subcutaneous fat were collected from crossbred cattle (Simmental × Mongolian cattle) and scored for fat colour. Liquid chromatography–mass spectrophotometry analysis of extracted metabolites from the subcutaneous fat of six animals with white fat and six animals with yellow fat was performed. Key results: The comparison between metabolites of white and yellow fat colour samples indicated that there were five categories of 235 significant metabolites, which included hydrocarbons, lipids and lipid-like molecules, organic acids and their derivatives, organic oxygen compounds and organoheterocyclic compounds. The principal-component analysis illustrated that yellow and white fat samples can be classified in groups; however, the metabolites of white fat samples showed greater variation than those in the yellow fat. In the white fat, there were 163 metabolites that had a higher relative abundance than in yellow fat and 72 that had a lower relative abundance than in yellow fat. 3-Hydroxyoctanoic acid, anethofuran, 9,10-DiHODE, furanoeremophilane, pregeijerene, N-glycolylneuraminic acid, and glycocholic acid were identified as the metabolites that differed the most in abundance between the white and yellow fat samples. Conclusions: This study has provided insights into the metabolic differences between white and yellow fat depots and identified key metabolites associated with beef fat colour. Implications: This study has provided potential biomarkers that may be useful for selection of beef fat colour in live animals. Fat colour is a major parameter for evaluating meat quality and is important in the beef industry. We performed analysis between white and yellow fat, so as to identify potential biomarkers for the selection of fat colour. These biomarkers are helpful with understanding of the molecular basis of fat colour. [ABSTRACT FROM AUTHOR]

Context: Electrical stimulation is often used by meat processors to promote fast muscle pH decline and optimise meat quality. Meat colour can be made more acceptable by this process, but how this relates to the microstructure and light-scattering properties of muscle is still unknown. Aims: To investigate the effect of electrical stimulation of beef carcasses on the meat colour at grading and the role of the muscle fibre microstructure and light scattering in determining colour differences. Methods: Electrical stimulation inputs (electrical stimulation inputs (ES), n = 8; no electrical stimulation inputs (NS), n = 8) were applied to beef carcasses from female cattle of approximately 18–24 months of age. ES comprised electrical immobilisation, bleed rail electric simulation and hide puller rigidity probe, which have all been shown to increase pH fall post-mortem in beef carcasses. pH fall was monitored, the longissimus thoracis was graded at 20–22 h postmortem and measurements were made of colour, muscle-fibre structure and light scattering. Key results: The decline of pH was increased in ES relative to NS, as indicated by lower pH at 2 h postmortem (5.83 vs 6.86 respectively, s.e. = 0.068; P < 0.05) as well as changes in both chromatic colour a* b* and achromatic (no colour) lightness in the muscle. Chromatic changes were evident as higher grader colour scores, increased redness (a*) and yellowness (b*) with higher levels of oxymyoglobin and lower levels of deoxymyoglobin. Achromatic changes were evident as increased lightness (L*) and surface reflectance (%R) at the meat surface, and increased global brightness within the muscle fibres. Conclusions: Increased lightness and brightness in electrically stimulated muscles were likely to be due to formation of contraction nodes and distortion of muscle fibres, which changed the microstructure of muscle in ways that increased its light-scattering properties. Implications: Consideration of the role of light scattering in determining beef colour at grading will advance understanding of how to improve this important quality trait. Beef meat colour can be affected by electrical stimulation (ES) of carcasses, but how this relates to the microstructure and light-scattering properties of muscle is still unknown. The effect of electrical stimulation inputs on beef longissimus thoracis muscles (n = 16) was investigated. ES promoted both chromatic colour a*b* and achromatic (no colour) lightness changes in the muscle. Increased lightness and brightness were likely to be due to formation of contraction nodes and distortion of muscle fibres, which changed the microstructure, increasing the muscle light-scattering properties. [ABSTRACT FROM AUTHOR]

Context: Planted grasses are becoming an increasingly important feed resource for tropical smallholder ruminant production; yet, limited research has been conducted to quantify productivity or enteric methane (CH4) production of animals consuming these grasses. Aim: An experiment was conducted to assess yields and nutritional attributes of the following three tropical grasses: Cenchrus purpureus var. Kakamega 1 (Napier), Chloris gayana var. Boma (Rhodes) and Urochloa brizantha var. Xaeres (Brachiaria), and quantify enteric CH4 production of cattle fed on them. Methods: Yearling Boran steers (n :18; initial liveweight 216 ± 5.8 kg (mean ± s.e.m.) were allocated to one of three grasses, in a completely randomised design and fed ad libitum for two feeding periods, each period lasting for 70 days. Intake, liveweight (LW), apparent total-tract digestibility and enteric CH4 production were assessed. The grasses used were grown on site and biomass yields were monitored over a 2-year period. Animal growth was also simulated to a final weight of 350 kg, and the amount of feed and size of land required to produce, and days to reach final weight, were estimated. Key results: Mean voluntary dry-matter intake (DMI) and ADG were higher (P < 0.05) in Period 2 than in Period 1, but did not differ among treatments (P > 0.05) within period. Methane yield (MY; CH4 g/DMI kg) was similar among treatments (26.7–28.5, P = 0.26) but Napier had a higher CH4 conversion factor [ Y m; CH4 (MJ)/gross energy intake (MJ)] than did Rhodes and Brachiaria (0.0987 vs 0.0873 and 0.0903 respectively; P = 0.013). Our modelling indicated that steers consuming Rhodes took at least 30 more days to reach the target LW, required larger land area for feed production and produced more enteric CH4 than did the other two diets. Conclusion: Even though animal performance and MY among treatments did not differ, the animals had higher MY and Y m than currently estimated by the Intergovernmental Panel on Climate Change. Implication: The three grasses supported similar animal growth rate, implying that growing of higher-yielding grasses such as Napier offers an opportunity to optimise land productivity in the tropics. However, suitable feeding practices such as protein supplementation need to be explored to enhance ruminant production and reduce enteric CH4 production. Cultivated grasses are an important feed resource for smallholder livestock keepers in East Africa, but animal performance studies when using these forages are limited and inconclusive. We measured growth rate and enteric methane production in growing Boran steers fed either Napier, Rhodes or Brachiaria and observed similar daily weight gains of about 0.5 kg and a higher methane production than currently estimated for high-forage diets. This implies up to 20% underestimation of enteric methane production by cattle in the region. [ABSTRACT FROM AUTHOR]

There is a growing demand for animal products, especially food for human consumption, including in developing countries in tropical regions of the world. Simultaneously, animal welfare and a reduced environmental impact are increasingly important to modern consumers and non-consumers. Increased efficiency of existing animal production systems is key to meeting the growing demand of animal products without ignoring societal concerns. Adequate animal welfare can play an important role in improving production and addressing consumer demands. This review describes the main cattle production systems in the tropics and considers how they meet the need for transparent animal welfare conditions. Several challenges to overcome are highlighted, including lack of information about the real cattle welfare status in the tropics. Adequate assessment protocols and improvements in animal nutrition, infrastructure, animal health and farming-related education need special attention in the region. Better animal welfare could improve tropical animal production in terms of productivity, and increase the volume of meat and milk delivered. It could also guarantee consumer acceptance and future consumption of animal products, secure incomes, alleviate poverty and reduce migration to urban areas and countryside abandonment. Animal welfare and sustainability are increasingly important to modern society. Better efficiency of existing farms is key to meeting the growing demand without ignoring societal concerns. Better animal welfare could improve tropical animal production in terms of volume and consumer acceptance. [ABSTRACT FROM AUTHOR]

The present study is a component of a multi-site experiment, using Bos tauruscattle generated at four locations across southern Australia, designed to examine postweaning growth pathways for progeny whose sires were extreme in retail beef yield and intramuscular fat. Treatment and interaction effects on beef production and meat quality were examined within and across sites. The present paper describes the effect of postweaning growth and sire carcass type on liveweight and carcass traits at the Hamilton site. Angus sires selected on estimated breeding values for extremes in retail beef yield (RBY%), intramuscular fat (IMF%) (estimated breeding values for IMF% are derived by using live-animal ultrasound scanning) or both and sire breed types considered to be more extreme in those traits (Limousin, and Belgian Blue for yield, and Wagyu for intramuscular fat) were joined to crossbred and straight-bred cows. After weaning, the resultant 645 steer and heifer progeny were grown on a fast and slow growth path to ~550 kg and slaughtered, averaging 0.68 kg/day and 22.2 months, and 0.49 kg/day and 27.8 months for growth rate and age at slaughter, respectively. Growth path, sire carcass type and sex affected carcass traits; however, there were no sire carcass type by growth treatment interactions. The fast growth-path cattle were fatter, had more intramuscular fat (measured chemically), a higher Meat Standards of Australia (MSA) USA and AUS marble score, and a higher predicted MSA eating-quality score. Progeny of Wagyu sires were lighter at weaning and slaughter and had a lower hot standard carcass weight than the other sire carcass types. The Belgian Blue and Limousin progeny had a higher dressing percentage, a higher RBY% and a lower P8 and rib-fat depth and lower IMF% than the other sire breed types. Progeny of the high RBY% Angus had a lower rib-fat depth, a lower IMF% and higher RBY% than those selected for high IMF%. There was no difference in IMF% between the Wagyu or the high IMF% Angus. Progeny from the Belgian Blue, Limousin and Wagyu had a larger eye muscle area than the other sire breeds. The results indicate that simultaneous selection for supposedly antagonistic traits of IMF% and RBY% would result in carcass having high values of both measurements. Females were lighter than steers at slaughter, had a lower hot standard carcass weight, were fatter at the P8 and rib, and had a higher marble score and IMF%, a lower yield and a lower MSA-predicted eating-quality score than did steers. There was no interaction between postweaning growth and sire carcass type. These results indicate that with the use of appropriate sire carcass types and BREEDPLAN, and post-weaning nutrition, beef producers can confidently change carcass parameters to suit market specifications. [ABSTRACT FROM AUTHOR]

Context. The present work was motivated by beef breeder concerns that selection for high growth and low fat in steers and low mature weight in cows will lead to cows that have low body condition and, therefore, productivity. Aims. The aim of this was to partition cow weight into size (associated with height) and condition (variation net of height) and test whether the trait net weight is a worthy addition to breeding programs. Methods. Angus cows (5901) were measured as heifers (4889) and at pre-calving and weaning of their first and second calf (minimum 2690) for weight, height and body condition traits (condition score, ultrasound eye-muscle area, P8 and rib fat depth, and intramuscular fat percentage). A novel trait was developed by fitting height as a covariate to weight, with the residuals termed net weight. Key results. Net weight was both heritable and genetically correlated with cow condition score and ultrasound measures. However, despite having a lower heritability, condition score was a more effective measure for genetic improvement of cow condition. Conclusions. A measure of cow condition should be included in genetic evaluation programs but net weight is unlikely to be that measure. Implications. Condition score should be recorded at the time of mature cow weight for breeding programs. [ABSTRACT FROM AUTHOR]

Context. Overseas studies have quantified production differences of Hereford Angus crossbreds compared with purebred Angus for a range of traits including growth, carcass and reproductive traits. Aim. This study aimed to quantify breed and heterosis effects using genomics. Methods. Thirty Hereford and 30 Angus sires were mated to 1100 Angus cows and heifers in a large commercial herd run on pasture at Musselroe Bay, Tasmania. Approximately 1650 calves were born. Steers (743) were grown for an average of 23 months and then slaughtered. Results. Heterozygosity effects were significant for birth, weaning and carcass weight and also loin eye-muscle area. On average, higher-quality (percentile) Hereford than Angus bulls were used. Breeding values were calculated for sires and could be compared with a common base given they also had BREEDPLAN breeding values published. Conclusions. When heterozygosity was accounted for and when compared on a common base, progeny of average Angus sires were superior to progeny of Hereford sires for birthweight, carcass weight, eye-muscle area and intramuscular fat. Implications. The method of benchmarking breeds using crossbred cattle and genomics provides a model for rapid adoption of multi-breed estimated breeding values, which is desirable for commercial beef producers. [ABSTRACT FROM AUTHOR]

Context. Genomic profiles are the only information source that can uniquely identify an individual but have not yet been strongly considered in the context of paddock to plate traceability due to the lack of value proposition. Aim. The aim of this study was to define the minimum number of single nucleotide polymorphisms (SNP) required to distinguish a unique genotype profile for each individual sample within a large given population. At the same time, ad hoc approaches were explored to reduce SNP density, and therefore, the size of the dataset to improve computing efficiency and storage requirements while maintaining informativeness to distinguish individuals. Methods. Data for this study included two datasets. One included 78 411 high-density SNP genotypes from commercial Angus cattle and the other 2107 from a research data (1000-bull genome data). In a stepwise approach, different-size SNP panels were explored, with the last step being a successive removal resulting in the smallest set of SNPs that still produced the maximum number of unique genotypes. Key results. First study that has demonstrated for large datasets, that ultra-small SNP panels with 20-23 SNPs can generate unique genotypes for up to ~80 000 individuals, allowing for 100% matching accuracy. Conclusions. Ultra-small SNP panels could provide an efficient method to approach the large-scale task of the traceability of beef products through the beef supply chain. Implications. Genomic tools could enhance supply-chain traceability. [ABSTRACT FROM AUTHOR]

Context: In the belief that feed costs and use of cereal grains are reduced, production systems based on grazed and conserved forage in which cattle are slaughtered at 30 to 36 months of age are increasingly advocated. Aims: As there is a scarcity of information concerning meat quality traits of beef from such extended rearing systems, three finishing systems of different lengths (Short, 14–16 months; Medium, 20–24 months; Long, 31–34 months) were compared in which cattle were slaughtered at similar conformation and fat classification scores. Methods: The experiment comprised a three (system) × two (gender) design with 24 Limousin cross-bred cattle (12 steers and 12 heifers) assigned to each system. Characteristics of the rib section (between and inclusive of the 5th and 10th ribs) and sensory properties of M. longissimus thoracis samples were then assessed. Key results: Older (Long system) cattle had greater rib section and L. thoracis weights. L. thoracis was tougher in older (Long system) cattle when assessed by a trained sensory panel. Heifers had lower rib section weights than steers but neither rib section composition or meat toughness differed between genders. Gristle (visible connective tissue) in the rib section increased with system length and was associated with an increased perception of gristle on eating. Conclusions: Overall meat quality was considered commercially acceptable regardless of system. Implications: The likely increased greenhouse gas emissions but reduced utilisation of food resources from the Long system need to be considered in conjunction with the meat quality characteristics of the system. There is on-going debate over how the eating quality of beef is influenced by the age at which cattle are slaughtered. When the eating quality of beef derived from cattle ranging from 14 to 34 months in age was compared, overall, there were few differences due to age and beef was of satisfactory eating quality. However, the likely increased greenhouse gas emissions from the older cattle need to be considered when assessing beef quality characteristics. [ABSTRACT FROM AUTHOR]

Context. The texture of beef is highly important for the eating experience, and there is a continued interest in understanding the biochemical basis for the variation in texture between cattle and their meat cuts in order to improve and minimise variation in tenderness due to production and processing factors. Aims. The present study aimed to investigate the impact of characteristics of meat on Warner-Bratzler shear-force (WBSF) as an indicator of texture of beef as affected by breed type, age/feeding phase, and muscle. Methods. Seventy-five steers of three breed types (Angus, Hereford and Wagyu · Angus) were slaughtered after weaning 6 months old (n = 15), after backgrounding 17 months old (n = 30) and after feedlotting 25 months old (n = 30). At slaughter three muscles (M. supraspinatus, M. semitendinosus and M. longissimus lumborum) were sampled from each steer, and pH, intramuscular fat and collagen content, sarcomere length, and proteolysis (desmin degradation) were measured and used to explain the variation in WBSF after 7 and 14 days of aging. Key results. Meat from Hereford and Angus steers had higher WBSF after 7 days of aging compared with Wagyu · Angus steers, but after 14 days of aging there was only a difference between Hereford and Wagyu · Angus in the M. supraspinatus and M. semitendinosus. The WBSF of the young weaned steers and steers slaughtered after backgrounding were dependent on the degree of proteolysis in the muscles, whereas for steers slaughtered after feedlotting the content of collagen was more important for theWBSF. The amount of intramuscular fat had a significant impact on the differences in WBSF within the specific muscle studied. In contrast to the general dogma that WBSF increase with age, WBSF decreased in M. semitendinosus and M. longissimus lumborum from the weaned 6-month-old steers to the 25-month-old steers finished in feed-lot, whereas in M. supraspinatus the older feed-lot finished steers had a higher WBSF. Conclusion. The factors contributing to the Warner-Bratzler shear force of beef depends on the age/feeding phase of the animal and the muscle and less on the breed type. Implications. Optimisation of texture in beef through breeding and production should address different traits dependent on the age/feeding phase of the slaughter animal. [ABSTRACT FROM AUTHOR]

Context: The most common way of pricing beef carcasses is through a price grid. Most processors make greater profit from higher-quality carcasses, which are those with higher meat yield and eating quality. Aims: The aim of this study was to calculate the value of diverse carcasses and compare pricing mechanisms on their ability to discriminate variation in meat yield and predicted eating quality. Methods: Hereford cross steer carcasses (153) were boned out to record saleable meat and yield. Six methods were used to calculate carcass price (AU$/kg). All were adjusted to the same average carcass value to allow comparisons, assuming that the overall payment does not change, but comparing the effect of having greater premiums and discounts. The six prices were based on a commercial grid, grid plus eating quality premium, yield of saleable meat only (constant price for all saleable meat), yield with eating quality premium, then the yield prices with optimum (quadratic) weight and fatness penalties based on grid optimums. Key results: Measurements of meat quality (eye muscle area and marble score) or saleable meat yield accounted for no variation in the grid price. However, measurement of yield accounted for substantial variation in prices calculated from yield and eating quality. Conclusions: The current grids do not encourage high-quality meat production and, assuming that yield and eating quality are important to processors, an actual measurement of yield is crucial to guide processing decisions (e.g. cutting plans) to maximise carcass value and feed market signals back to beef producers. Implications: Improved measurement of meat yield is required if carcass prices are to reflect carcass quality or the potential value captured. Six methods were used to calculate carcass price (AU$/kg). Measurement of yield accounted for substantial variation in prices calculated from yield and eating quality. This demonstrates that an actual measurement of yield is crucial to guide processing decisions to maximise carcass value and feed market signals back to beef producers. [ABSTRACT FROM AUTHOR]

Context: The finishing of late-maturing bulls on grass is economically more favourable than finishing on cereal concentrates but it may have a negative effect on oxidative stability. Aim: To determine the effect of varying levels of pasture feeding during the finishing period on the oxidative stability of bull beef. Methods: Groups of eight late-maturing breed sired bulls were assigned to one of the following production systems: (1) pasture only for 200 days (P), (2) pasture only for 100 days followed by pasture plus 50% of the dietary dry matter (DM) intake as concentrate for 100 days (P-C50), (3) pasture plus 50% of the DM intake as concentrate for 200 days (C50), (4) pasture only for 100 days followed by ad libitum concentrates for 100 days (P-C), (5) pasture plus 50% of the DM intake as concentrate for 100 days followed by ad libitum concentrates for 100 days (C50-C) and (6) ad libitum concentrates offered indoors for 200 days (C). The M. Longissimus thoracis et lumborum muscle was excised post-slaughter for proximate, fatty acid and α-tocopherol analysis and for measurement of lipid and protein oxidation and colour stability. Results: The polyunsaturated fatty acid (PUFA) concentration and proportion in muscle were higher (P < 0.001) in C50 bulls compared with P, P-C50 and P-C bulls. The concentration of highly peroxidisable PUFA was at least 1.3-fold higher (P < 0.001) in the muscle of C50 bulls than of C and P-C bulls whereas the proportion was at least 1.5-fold higher (P < 0.001) in muscle of P, P-C50 and C50 bulls compared with C and P-C bulls. There was a higher (P < 0.001) concentration of saturated fatty acids and monounsaturated fatty acids in muscle of bulls fed on concentrate in the last 100 days (P-C, C50-C and C) compared with those fed on grass (fully or partially) in the last 100 days (P, P-C50 and C50). α-Tocopherol concentration was at least 1.5-fold higher (P < 0.001) in muscle of P bulls compared with C, C50-C and P-C bulls. Redness, redness stability, lipid and protein oxidation did not differ between treatments (P > 0.05). Conclusions: The increase in highly peroxidisable PUFA in beef, by increasing pasture in the finishing ration did not increase susceptibility to oxidation, most likely due to a concomitant increase in α-tocopherol. Implications: Beef can be produced from late-maturing bulls grazing on pasture for 200 days without impacting negatively on oxidative stability. Grass finishing of later maturing bull beef cattle is more economically efficient compared with concentrate finishing. In a study with animals finished with various levels of grass input at pasture the production of beef from grass-based finishing systems resulted in a higher proportion of polyunsaturated fatty acids but the oxidative shelf life of beef was not adversely affected. Therefore, late maturing bulls can be finished on grass without negatively impacting on the shelf life of beef. [ABSTRACT FROM AUTHOR]

Context. Cold-pressed rapeseed cake is a by-product of biodiesel manufacturing that can be obtained on-farm after simple mechanical extraction of the oil. It has a high crude fat content and contains significant amounts of linoleic acid, which make it a promising lipid supplement to modulate meat fatty acid profile. However, previous studies have indicated that using unsaturated fats in beef cattle diets could promote lipid oxidation and reduce meat redness. Aims. The present study aimed to evaluate the effects of supplementation of intensively fattened beef steers with cold-pressed rapeseed cake on the fatty acid composition of beef fat and changes in measures of meat colour and lipid oxidation during 6 days of aerobic storage. Methods. Sixteen Limousin steers were divided into two homogeneous groups and were fed ad libitum with barley straw and a concentrate mixture supplemented with either PROGRAS (PROGRAS at 2.7% of the diet, high in palmitic acid C16:0 from palm oil; CTR, experimental control; n = 8) or cold-pressed rapeseed cake (CPRC at 14.8% of the diet; CPRC treatment; n = 8) for a period of 9 months. The growth performance and carcass traits were assessed. The intramuscular fatty acids were analysed and the colour stability and lipid oxidation were measured in meat stored aerobically at 4°C for 0, 3 or 6 days. Key results. Slaughter bodyweight and average daily gain were not affected by the inclusion of CPRC in the diet. Nor were there any changes in carcass weight, conformation or fatness. The longissimus thoracis from CPRC-fed animals depicted a higher UFA-SFA ratio and a lower atherogenic index than did that from animals fed CTR. Feeding CPRC increased the oleic acid , the vaccenic acid and the rumenic acid proportions in the muscle fat without affecting the ratio of C18:1 trans-10 to C18:1 trans-11. The extents of lipid oxidation and colour deterioration during aging were not affected by the dietary treatments. Conclusions. The use of cold-pressed rapeseed cake as a lipid supplement in beef-steer diet improved the fatty acid profile of muscle fat without compromising meat oxidative stability, animal growth performance and carcass characteristics. Implications. The supplementation of beef-steer diet with cold-pressed rapeseed cake could be an advantageous economical strategy allowing exploitation of an important by-product of small-scale biodiesel manufacturing to provide consumers with healthier meat. [ABSTRACT FROM AUTHOR]

Tenderness, flavour and colour are the most important quality traits of beef that are influenced by breed and age. Suckler calves (SC) produce very tender, high-quality meat. Extensively growing, small-framed breeds are known for high-quality beef, but information about the particularly small Dexter cattle (D) is yet unavailable. Eight D and seven Charolais-crossbreed SC were kept for 11 weeks on alpine pastures to be able to compare their meat quality. The SC were kept with their dams. The animals of the two breeds were slaughtered at different ages (D: 15 months and SC: 7 months) consistent with their respective production system conventions. Although this meant that age and breed effects were confounded, slaughter took place at the same carcass fatness score, thereby avoiding a confounding effect on meat quality. Quality of the carcass and of two muscles (M. biceps femoris , M. longissimus thoracis) was analysed. Despite being older, D had lower body and carcass weights, dressing percentage and bodyweight gains than SC. Dexter meat was darker than SC meat. Shear force did not differ between D and SC in the M. longissimus thoracis but was higher in the M. biceps femoris from D than from SC. Sensory analysis by a trained panel demonstrated an overall preference for D meat, associated with more favourable flavour and juiciness. Tenderness was not rated differently. Despite the unfavourable darker colour of D compared with SC meat, its characteristic flavour might attract consumers in a high-price niche market. For a more comprehensive characterisation, sensory evaluation of additional muscles is required. Additional measurements on a larger number of animals and muscles are required. Carcass and meat quality of Dexter cattle were analysed and compared with the high-quality standard meat produced by suckler calves. Dexter cattle had an inferior carcass quality and darker meat. Shear force of the M. longissimus thoracis of Dexter beef did not differ from that of Charolais-cross suckler calves. Sensory analysis confirmed the lack of a significant difference in tenderness between meat of Dexter cattle and that of suckler calves, but panellists clearly preferred the Dexter meat because of superior flavour and juiciness. [ABSTRACT FROM AUTHOR]

Adding tannins to the dietary protein source will cause complexation between the tannin and protein, which may increase dietary ruminal undegraded protein. Thus, this study aimed to evaluate the effects of replacing soybean meal (SM) with soybean meal treated with tannin (SMT) on the intake, partial and total nutrient digestibility, and protein dietary efficiency of young cattle fed a high-concentrate diet. Five Nellore bulls with bodyweights of 290 ± 11.2 kg were fitted with ruminal and abomasal cannulas and were used in the study. The experimental diets included 7.5% SM, with a proportion of that SM (0%, 33%, 66% or 100%) replaced with SMT. Another treatment (SMT+urea) with only 2.5% SM treated with tannins was tested. The intake of ether extract and the intake of neutral detergent fibre ash and protein were the only parameters related to feed intake that were affected by the replacement of SM with SMT. Ruminal and intestinal digestibility each showed a linear effect on crude protein, which decreased with ruminal digestibility and increased with intestinal digestibility. The intake of ruminal undegraded protein and metabolisable protein showed a positive linear correlation with the amount of SMT in the diet. SMT substitution showed no effect on methane emission. The replacement of traditional SM with SM treated with 2.5% tannins (85% condensed tannins and 15% hydrolysable tannins) for cattle that were fed high-concentrate diets showed increased amounts of metabolisable protein and decreased nitrogen loss per unit of crude protein, without changing the methane emission. Tannins provide an increase in the amount of protein used by the animal with no increase in the total amount of dietary protein. This occurs due to the capacity of tannin to bind protein through hydrogen bonds forming a tannin–protein complex, which is stable in the rumen (pH, 5.0–7.0) and resistant to microbial degradation. This approach can provide two important benefits: an increase in the amount of protein absorbed and deposited in the animal's tissue and a decrease in feed costs due to the removal of protein source ingredients, such as soybean meal. [ABSTRACT FROM AUTHOR]

Feeding wet distillers grains plus solubles (WDGS) in beef feedlot diets increases beef polyunsaturated fatty acids (PUFA) concentration and decreases shelf-life; whereas feeding antioxidants like vitamin E and Agrado-Plus (AG; an ethoxyquin and tert-Butylhydroquinone mixture) mitigates such effects. The objective of this study was to evaluate shelf-life of beef from steers supplemented with WDGS and different antioxidants. One hundred and sixty steers were finished on a corn-based diet with 0% WDGS or 30% WDGS and four antioxidant treatments (no supplementation; vitamin E only; AG only; vitamin E + AG). Ten strip loins from each treatment were collected, aged, cut into steaks, and placed under retail display (2±2°C). During retail display, steaks were evaluated daily for objective colour and subjective discolouration. After retail display, steaks were used to measure lipid oxidation, muscle fatty acids, and vitamin E and ethoxyquin concentrations. Feeding 30% WDGS increased total PUFA in beef when compared with beef from steers fed 0% WDGS (P < 0.05). Supplementing vitamin E or vitamin E + AG was effective in decreasing myoglobin and lipid oxidation in steaks from steers fed 0% or 30% WDGS after retail display (P < 0.01). Supplementation of vitamin E or AG also increased (P < 0.01) muscle tissue vitamin E or ethoxyquin levels, respectively, compared with the diets without vitamin E or AG supplementation. The inclusion of 30% WDGS altered beef fatty acid profiles, but did not promote lipid and myoglobin oxidation compared with the 0% WDGS diet. Feeding vitamin E was effective, whereas supplementing AG had minor effects in decreasing myoglobin and lipid oxidation in steaks from both diet. [ABSTRACT FROM AUTHOR]

In the past, the adoption of online measurement technologies for measuring carcass and meat quality traits objectively has been low among Australian red meat processors. The aim of the present work was to obtain a greater understanding of Australian processor views on the value of objective online measurement technologies. This was achieved through consultation with 65 Australian processors, to understand which carcass and meat quality traits they considered important to objectively measure and what they thought of current and future technologies. It was shown that beef processors ranked meat colour and tenderness as the most important traits (P < 0.001) to objectively measure online. Sheep processors ranked tenderness, pH, age, meat colour, total tissue depth at the 12th rib 110 mm from the midline (GR) and saleable meat yield percentage as the most important traits (P < 0.001) to objectively measure online. The overall processor responses indicated that there is support for online measurement technologies, with 80% of processors stating that online objective grading systems have a role in the Australian meat processing sector now and 88% considered these to have a role in the future. Much can be learned from the implementation of previous online objective measurement technologies by processors in terms of commercialisation and adoption strategies. The development and adoption of objective online measurement technologies is challenging and complex. However, increased adoption of online measurement technologies has the potential to achieve benefits to the whole of industry and needs continued support, coupled with new approaches to enhance adoption. [ABSTRACT FROM AUTHOR]

This experiment has quantified the methane abatement potential of nitrate in the context of extensively managed cattle. The experimental protocol consisted of two, 4 ⨰ 4 Latin square design using eight rumen fistulated Bos indicus steers fed Flinders grass (Iseilema spp.) hay ad libitum. The treatments were Control (nil nitrogen supplement), urea (32.5 g/day urea) and two levels of calciumnitrate: CaN1 and CaN2 (to provide 4.6 g and 7.9 g NO3/ kg DM equivalent to ∼0.46% and 0.80% of DM, respectively). Complete supplement intake was ensured by dosing any supplement that had not been voluntarily consumed, through the rumen fistula, 1 h after feeding. Enteric methane production was measured using open circuit respiration chambers. Methane yield (g/kg DM intake) from the CaN2 treatment tended to be lower (P < 0.07) than either the Control or urea treatments. There were no significant differences in methane yield between Control, urea or CaN1 treatments. Mean blood methaemoglobin concentrations were significantly (P < 0.001) higher for CaN2 animals compared with the Control, urea or CaN1 treatments. In addition, a significant time effect after dosing (P < 0.001) and a significant interaction between treatment and time after dosing (P < 0.001) was apparent. Overall mean total volatile fatty acid concentration was 74.0 ± 1.53 mM with no significant treatment effect, but a significant effect for both time of sampling (3 h vs 6 h) within days and among 7 sampling days. The inclusion of calcium nitrate as a non-protein-N source significantly reduced the molar proportions of butyrate (P < 0.001), iso-butyrate (P < 0.05) and iso-valerate (P < 0.001) compared with the Control. The provision of nitrate supplements, providing both a NPN and an alternative sink for H that would otherwise support enteric methanogenesis, has some potential. In extensive grazing systems effective methane abatement strategies are required. The elevated concentration of MetHb using CaN2 suggests that the strategy of replacing urea with nitrate in supplements fed to extensively managed cattle in the northern rangelands may be inappropriate where supplement intake cannot be controlled on an individual animal basis and forage quality is seasonally variable.. [ABSTRACT FROM AUTHOR]

A mixed herd of five cows, five mares, 32 ewes and 32 goats was managed with their offspring during two consecutive years in a paddock (22.3 ha) with 76% of heathlands and 24% of improved pasture area, with the aim of studying their differences in ingestive behaviour and performance. Diet composition, dry matter intake (DMI) and digestibility (DMD) were estimated on three occasions using the alkane technique, and all animals were periodically weighed to calculate bodyweight (BW) changes per livestock unit (LU). Goats selected higher proportions of shrubs than the other herbivore species (P < 0.001). Overall, daily DMI was higher (P < 0.001) in equines (218 g/kg BW0.75) than in ruminants (174, 121 and 80 g/kg BW0.75 for cattle, goats and sheep, respectively), whereas DMD was lower (P < 0.001) in equines (569 g/kg DM) compared with ruminants (733-791 g/kg DM). During the first half of the grazing season (from late April to mid-July), dams' BW changes per LU did not differ between species. However, during late summer-autumn lower (P < 0.001) BW losses per LU were observed in sheep and goats (-89 g/day) than in cattle (-534 g/day), being intermediate in horses (-254 g/day). For the overall grazing season, ewes and goats showed greater (P = 0.056) BW gains per LU (338 g/day) than cows and mares (178 g/day). Regarding the offspring, BW gains per LU were greater (P < 0.001) in lambs (3612 g/day) than in other species. Calves presented greater gains than kids (2647 vs 1909 g/day.LU), whereas foals showed intermediate gains (2385 g/day.LU). Therefore, under these conditions of partially improved heathlands, sheep was the most productive species. However, looking at the diet selection and digestibility, goats could complement sheep or cattle herds by achieving a more efficient utilisation of heathland vegetation, and increasing overall productivity per hectare. By contrast, horses, having high levels of grass intake, compete with cattle and sheep for pasture utilisation. [ABSTRACT FROM AUTHOR]

The methods for estimating methane emissions from cattle as used in the Australian national inventory are based on older data that have now been superseded by a large amount of more recent data. Recent data suggested that the current inventory emissions estimates can be improved. To address this issue, a total of 1034 individual animal records of daily methane production (MP) was used to reassess the relationship between MP and each of dry matter intake (DMI) and gross energy intake (GEI). Data were restricted to trials conducted in the past 10 years using open-circuit respiration chambers, with cattle fed forage-based diets (forage >70%). Results from diets considered to inhibit methanogenesis were omitted from the dataset. Records were obtained from dairy cattle fed temperate forages (220 records), beef cattle fed temperate forages (680 records) and beef cattle fed tropical forages (133 records). Relationships were very similar for all three production categories and single relationships for MP on a DMI or GEI basis were proposed for national inventory purposes. These relationships were MP (g/day) = 20.7 (0.28) · DMI (kg/day) (R2 = 0.92, P < 0.001) and MP (MJ/day) = 0.063 (0.008)· GEI (MJ/day) (R2 = 0.93, P < 0.001). If the revised MP (g/day) approach is used to calculate Australia's national inventory, it will reduce estimates of emissions of forage-fed cattle by 24%. Assuming a global warming potential of 25 for methane, this represents a 12.6 Mt CO2-e reduction in calculated annual emissions from Australian cattle. [ABSTRACT FROM AUTHOR]

Rice whole stillage (RWS) is disposed to aerobic spoilage when stored for a prolonged period. The objectives of the present study were to evaluate the fermentation characteristics of ensiled RWS with wheat straw (WS) and wheat bran (WB) inoculated with Amylomyces rouxii, as well as to evaluate their impact on the metabolic profiles and the growth performance in Japanese black steers. Ensiled blends containing RWS, WS and WB were prepared either with A. rouxii inoculation (AS) or without (US). Fifteen silo bags were made for each blend; each bag had a width x height of 110 x 110 cm. The silos were analysed on Days 0, 7, 14, 28, 42 and 60 after ensiling. Notably, crude protein concentrations were found to be higher in the US treatment than in the AS treatment. In contrast, ash and acetic acid concentrations were elevated in the AS treatment compared with the US treatment. Lactic acid (LA) concentrations did not differ between the two treatments. Furthermore, the feeding efficacies of the prepared silages were evaluated as a feeding material for Japanese black steers. Control diets were composed of total mixed ration (TMR) and timothy hay, and the test diets were composed of TMR supplemented with either 1 kg/head.day US silage blend (USTMR) or 1 kg/head.day AS silage blend (ASTMR). Steers fed on the ASTMR diet exhibited a decrease in blood LA concentrations compared with the other groups. Moreover, growth performance revealed that daily gain and final bodyweight values were similar among treatments. Collectively, RWS can be effectively ensiled with or without A. rouxii and used as a feedstuff for maintaining an adequate growth rate of steers. Rice whole stillage (RWS) is disposed to aerobic spoilage when stored for a prolonged period. The objectives of this study were to evaluate the fermentation characteristics of ensiled RWS and their feeding impact on Japanese black steers. Results revealed that RWS can be stored by ensiling for a prolonged period without spoilage, and was successfully used for feeding steers. Collectively, ensiling RWS provides a promising nutritional feedstuff for beef producers. [ABSTRACT FROM AUTHOR]

Brazil is the world's largest exporter of beef and home to the world's biggest commercial beef herd. So a study was conducted to understand how the Brazilian cattle industry has developed, by analysing the Agricultural Censuses carried out in 1985, 1995 and 2006. Databases (per region) were collected: bovine herd, total pasture area (natural and cultivated) and forage storage silos, and the stocking rate calculated (heads/ha). Brazilian regions are: North, North-east, South-east, South and Midwest. The average annual growth rate (%/year) was calculated. In 1985, Brazil had 128 million bovine heads, raised on 179.2 million hectares of pasture (0.71 head/ha). In 2006, the bovine herd went up to 176.1 million heads, raised on 160 million hectares of pasture (1.1 head/ha). The North region (Amazon forest) showed the highest growth in bovine herd (6.3%/year), and in total (1.2%/year) and cultivated (4.0%/year) pasture areas, increasing the stocking rate from 0.43 (1985) up to 1.21 head/ha (2006). The Midwest region accounted for the largest bovine herd in 2006 and showed the second highest growth in herd size (2.4%/year) and in cultivated (1.9%/year) pasture area, increasing the stocking rate from 0.61 (1985) up to 1.01 head/ha (2006). The South-east and South regions (the most developed regions) presented negative growth in herd size and total pasture, but with the highest stocking rate in 2006 (1.24 and 1.5 head/ha, respectively). The displacement of the cattle industry towards North concerns the government, due to the Amazon's deforestation, but the intensification of the production system has relieved the pressure on the forest. Brazil is the world's largest beef exporter and has the biggest commercial bovine herd. This study aimed at evaluating the development of the Brazilian cattle industry in the different regions and showed that it has migrated to Midwest and North. Fortunately the technology in the agricultural frontier has been adopted at the same rate as the cattle have migrated into it. [ABSTRACT FROM AUTHOR]

Protein restriction in early bovine gestation affects post-natal reproduction and production traits in progeny. This experiment evaluated the effects of dietary protein restriction during the peri-conception period and first trimester in yearling heifers on conceptus growth and development; this period of dietary intervention being earlier than any previous bovine fetal programming studies. Three-hundred and sixty primiparous 12-month-old Santa Gertrudis heifers were individually fed high [14% crude protein (CP)] or low (7% CP) diets for 60 days before conception. At 23 days post-conception (dpc), each high (HPERI) or low (LPERI) group was again split into high (HPOST) or low (LPOST) protein groups yielding four treatment groups in a 2 x 2 factorial design. From the end of the first trimester of gestation (98dpc), the pregnant heifers were individually fed a 12% CP diet until parturition. Forty-six fetuses were excised at 98dpc. Sixty-four heifers went on to calve. Conceptus development was assessed via transrectal ultrasound from 36dpc, fetal necropsy at 98dpc and live calf measures at term. At 36dpc, HPERI diet increased fetal crown-rump length (CRL) (P < 0.05) and at the 60dpc scan, biparietal diameter (BPD) tended to be increased by HPOST diet (P < 0.1) though the greater effect upon BPD was still the HPERI diet (P < 0.05). At 60dpc, BPD in the male fetus was affected by the peri-conception diet (P < 0.05), while in females, BPD was not different among nutritional groups. These ultrasound measures of fetal growth were validated by measures of the excised fetus at 98dpc. Fetal weight was heavier (P < 0.01) in those whose mothers were fed the HPOST diet than their LPOST counterparts. Males fetuses were heavier than female fetuses (P < 0.001). Fetal CRL was increased by HPERI diet (P < 0.05) and tended to be increased by HPOST diet (P < 0.1). Fetal BPD tended to be increased by HPERI diet (P < 0.1). In males, BPD tended to be increased in those fetuses whose mothers were fed HPERI (P < 0.1). For females, maternal nutrition during PERI or POST did not affect BPD at 98dpc (P > 0.1). At term, no dietary effect on birthweight was observed (P > 0.1) and males were not heavier than females (P > 0.1). These results suggest that maternal protein intake during the peri-conception (-60 to 23dpc) and first trimester (24-98dpc) may influence early conceptus growth and development in the bovine. The long-term effects on offspring metabolism and post-natal development of this dietary intervention are yet to be determined. Effects of dietary protein restriction during the peri-conception period and first trimester in yearling heifers on conceptus growth and development were evaluated. Early conceptus development was altered by dietary treatment in a gender-dependant manner. Altered fetal growth could have long-term implications for offspring metabolism and development and warrants further investigation. [ABSTRACT FROM AUTHOR]