Estimation of the economic impact of heat stress on the Chilean dairy regions by using two comfort thermal indices.

The study aimed to estimate economic losses associated with heat stress in the eight dairy production regions (DPR), defined by the Dairy Chilean Consortium, using two comfort thermal indices, namely, the temperature-humidity index (THI) and the THI adjusted for solar radiation and wind speed (THIa). Hourly records from 19 weather stations (Nov - Mar 2017-2022) were collected to estimate the comfort thermal indices. The economic impact was estimated considering a critical threshold of 65 for both indices and the effect of higher values on loss in milk yield, days open, culling rate, and deaths. There were differences in the number of hours above the threshold among DPRs, independent of the thermal index used (P < 0.01). The greatest values were observed in DPRs I, II, and VIII, which concentrate most dairy cows. Average losses in milk yield were between 2.0 and 6.4 times higher when THIa was used instead of THI, which also depends on the DPR (P < 0.01). These estimations coincide with those observed empirically by producers. The lowest average economic losses per cow during the summer season (5 seasons average) occurred in DPR VI (US $ 91.5), and the highest losses were observed in DPR I (US $ 184.2) both using THIa. At the country level, economic losses fluctuate between US $ 29.0 and 108.4 million per summer season, depending on the comfort thermal index used. Finally, heat stress impacts negatively and significantly the Chilean dairy sector, which is highly dependent on the DPR.

The effect of parenteral vitamin B12 on the growth rate of dairy calves over the summer and autumn on seven farms from the Central Plateau, New Zealand.

AIMS: To investigate the effect of parenteral vitamin B12 supplementation on the growth rate of dairy heifer calves over the summer and autumn on seven farms from the Central Plateau of New Zealand, an area historically associated with low cobalt levels in grazing pasture. METHODS: This was a controlled clinical trial conducted on a convenience sample of seven farms with young female calves randomly assigned to three vitamin B12 treatment groups and followed through a grazing season. Two treatment groups received either monthly SC injections of a short-acting (SA) B12 formulation or 3-monthly injections of a long-acting (LA) B12 formulation and the third group received no treatment (NT). No additional parenteral vitamin B12 was given; however, all calves received additional cobalt (0.04-0.4 mg Co/kg liveweight) in the mineralised anthelmintic drenches given orally every month. Liveweight was recorded in December/January and at the end of the trial in May/June/July depending on farm. Pasture cobalt concentrations (mg/kg DM) were measured every month using 500-g herbage samples from 100-m transects in the area about to be grazed by the trial groups. RESULTS: There was evidence for a difference in growth rate between groups with mean final weight of 228 (95% CI = 212-243) kg for the LA groups, 224 (95% CI = 209-239) kg for the SA groups and 226 (95% CI = 211-241) kg for the NT groups respectively, (global p-value = 0.014). Calves given SA vitamin B12 were 3.77 (95% CI = 0.71-6.82) kg lighter than calves given LA vitamin B12 (p = 0.011). There was no evidence for a change in pasture cobalt concentrations (p = 0.32). CONCLUSIONS AND CLINICAL RELEVANCE: The results of this trial raise the question as to whether the routine use of vitamin B12 supplementation in young cattle from areas traditionally thought to be cobalt deficient is necessary, and further raise the possibility that vitamin B12 supplementation by repeated injection of SA products may negatively impact growth rates.

The colour and sensory characteristics of longissimus muscle from beef cattle that grazed grass or consumed concentrates prior to slaughter.

BACKGROUND: Grazed grass is an important component of the majority of beef production systems used in temperate climates. Compared to concentrate-fed beef, 'grass-fed' beef can command a premium in some markets based on perceived differences in appearance and sensory characteristics. The influence of grazed grass per se, as well as the duration of grazing, on selected sensory characteristics of beef within a heifer production system was examined. RESULTS: In general, fat from grass-fed cattle was more yellow than fat from similar cattle fed concentrates, whereas muscle from grass-fed cattle was darker than muscle from cattle fed concentrates. At the same carcass weight, muscle from grass-fed cattle had a lower fat concentration than cattle fed concentrates. In the most extreme situation examined, whereby early-maturing heifers were fed concentrates ad libitum from weaning or grazed grass/conserved grass throughout life, until slaughtered at a similar carcass weight (260 kg) and differed in age by 5 months, beef was rated similarly for tenderness and a range of flavours by a trained sensory panel. CONCLUSION: Within the range of beef heifer production systems examined, the sensory characteristics of grass-fed beef do not differ greatly from concentrate-fed beef. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Reducing climate impacts of beef production: A synthesis of life cycle assessments across management systems and global regions.

The global demand for beef is rapidly increasing (FAO, 2019), raising concern about climate change impacts (Clark et al., 2020; Leip et al., 2015; Springmann et al., 2018). Beef and dairy contribute over 70% of livestock greenhouse gas emissions (GHG), which collectively contribute ~6.3 Gt CO2 -eq/year (Gerber et al., 2013; Herrero et al., 2016) and account for 14%-18% of human GHG emissions (Friedlingstein et al., 2019; Gerber et al., 2013). The utility of beef GHG mitigation strategies, such as land-based carbon (C) sequestration and increased production efficiency, are actively debated (Garnett et al., 2017). We compiled 292 local comparisons of "improved" versus "conventional" beef production systems across global regions, assessing net GHG emission data from Life Cycle Assessment (LCA) studies. Our results indicate that net beef GHG emissions could be reduced substantially via changes in management. Overall, a 46 % reduction in net GHG emissions per unit of beef was achieved at sites using carbon (C) sequestration management strategies on grazed lands, and an 8% reduction in net GHGs was achieved at sites using growth efficiency strategies. However, net-zero emissions were only achieved in 2% of studies. Among regions, studies from Brazil had the greatest improvement, with management strategies for C sequestration and efficiency reducing beef GHG emissions by 57%. In the United States, C sequestration strategies reduced beef GHG emissions by over 100% (net-zero emissions) in a few grazing systems, whereas efficiency strategies were not successful at reducing GHGs, possibly because of high baseline efficiency in the region. This meta-analysis offers insight into pathways to substantially reduce beef production's global GHG emissions. Nonetheless, even if these improved land-based and efficiency management strategies could be fully applied globally, the trajectory of growth in beef demand will likely more than offset GHG emissions reductions and lead to further warming unless there is also reduced beef consumption.

Invited review: A 2020 perspective on pasture-based dairy systems and products.

Grazing pasture is the basis for dairy production systems in regions with temperate climates, such as in Ireland, New Zealand, parts of Australia, the United States, and Europe. Milk and dairy products from cows on pasture-based farms predominantly consuming fresh grazed grass (typically classified as "grass-fed" milk) have been previously shown to possess a different nutrient profile, with potential nutritional benefits, compared with conventional milk derived from total mixed ration. Moreover, pasture-based production systems are considered more environmentally and animal welfare friendly by consumers. As such, there is significant potential for market capitalization on grass-fed dairy products. As competition in this space increases, the regulations of what constitutes as grass-fed vary between different regions of the world. With this in mind, there is a need for clear and independently accredited grass-fed standards, defining the grass-fed criteria for labeling of products as such, subsequently increasing the clarity and confidence for the consumer. This review outlines the numerous effects of pasture production systems on dairy product composition, nutritional profile, and sustainability, and highlights potential future methods for authentication.

Invited review: Sustainability: Different perspectives, inherent conflict.

Consumer definitions of sustainability are largely uninformed by scientific research and may not align with industry definitions. Furthermore, consumers themselves have varied perceptions, definitions, and opinions of sustainability that vary between categories and products within the dairy category. Understanding these differences and developing marketing messaging aligned with consumer sustainability definitions offer an advantage to dairy product producers when strategically positioning their products in a changing marketplace. This review outlines the factors that may affect consumer sustainability perceptions to provide a basis for future marketing and scientific work. Consumer trends and desires for sustainability are explored, including how they are reflected in the rapid growth of plant-based alternatives. Factors that may influence consumer perception of dairy as sustainable are covered in detail, including packaging, labeling, animal welfare, organic status, grass-fed or pasture-raised feeding systems, and local and clean label perceptions. Finally, a discussion of the challenges of marketing dairy foods with sustainability messages is addressed.

A modelling approach to investigate the impact of consumption of three different beef compositions on human dietary fat intakes.

OBJECTIVE: To apply a dietary modelling approach to investigate the impact of substituting beef intakes with three types of alternative fatty acid (FA) composition of beef on population dietary fat intakes. DESIGN: Cross-sectional, national food consumption survey - the National Adult Nutrition Survey (NANS). The fat content of the beef-containing food codes (n 52) and recipes (n 99) were updated with FA composition data from beef from animals receiving one of three ruminant dietary interventions: grass-fed (GRASS), grass finished on grass silage and concentrates (GSC) or concentrate-fed (CONC). Mean daily fat intakes, adherence to dietary guidelines and the impact of altering beef FA composition on dietary fat sources were characterised. SETTING: Ireland. PARTICIPANTS: Beef consumers (n 1044) aged 18-90 years. RESULTS: Grass-based feeding practices improved dietary intakes of a number of individual FA, wherein myristic acid (C14 : 0) and palmitic acid (C16 : 0) were decreased, with an increase in conjugated linoleic acid (C18 : 2c9,t11) and trans-vaccenic acid (C18 : 1t11; P < 0·05). Improved adherence with dietary recommendations for total fat (98·5 %), SFA (57·4 %) and PUFA (98·8 %) was observed in the grass-fed beef scenario (P < 0·001). Trans-fat intakes were increased significantly in the grass-fed beef scenario (P < 0·001). CONCLUSIONS: To the best of our knowledge, the present study is the first to characterise the impact of grass-fed beef consumption at population level. The study suggests that habitual consumption of grass-fed beef may have potential as a public health strategy to improve dietary fat quality.

Raman spectroscopy: A rapid method to assess the effects of pasture feeding on the nutritional quality of butter.

The animal diet is a critical variable affecting the composition and functionality of dairy products. As "Grass-Fed" labeling becomes more prominent on the market, rapid and label-free methods for verification of feeding systems are required. This work proposes the use of Raman spectroscopy to study the effects of 3 different experimental cow feeding systems-perennial ryegrass pasture, perennial ryegrass with white clover pasture, and an indoor total mixed ration diet (TMR)-on the nutritional quality of sweet cream butter. The results demonstrate that Raman spectroscopy coupled with multivariate analysis is a promising approach to distinguish butter derived from pasture or conventional TMR feeding systems. A Pearson correlation analysis confirmed high positive correlations between the spectral bin at 1,657 cm-1, ascribed to the stretching vibrations of C=C bonds, and concentrations of α-linolenic acid and conjugated linolenic acid (CLA) in butter, and in general with the concentration of n-3 and n-3+CLA fatty acids and polyunsaturated fatty acids in the samples. The yellow color indicative of the presence of carotenoids in butter, which has previously been suggested as a biomarker of pasture or "Grass-Fed" feeding, was also positively correlated with the data obtained from the Raman spectra. Raman spectroscopy could also be used to accurately predict indicators of the nutritional quality of butter, such as the thrombogenic index, which showed a strong negative correlation with the spectral bin at 3,023 cm-1.

Fibrolytic enzymes improving in vitro rumen degradability of tropical forages.

During specific times of the year, especially dry seasons, tropical forages typically have poor nutritional value due to high contents of neutral and acid detergent fibres, and low crude protein in their composition, which may reduce productivity of ruminant livestock production and lead to increased enteric methane (CH4 ) emissions per unit of generated product in forage-bases systems. In order to increase fibre degradability and the efficiency of energy utilisation from low-quality forages, exogenous fibrolytic enzymes have been studied. In this assay, we evaluated the effects of increasing dose levels of fibrolytic enzymes extract (FEE) produced by Trichoderma reesei on in vitro rumen organic matter degradability, fermentation parameters, total gas and CH4 production of tropical forages. Forage samples were analysed for their bromatological composition, and enzyme activity from FEE was performed for xylanase and endoglucanase. The in vitro gas production technique was used in a 5 × 3 factorial arrangement with five FEE dose levels (0, 5, 50, 500 and 5,000 µl) and three substrates (Cynodon spp., Panicum maximum and Cenchrus ciliaris L.). The highest dose level of FEE increased degradability, total gas and CH4 production in all substrates (p < .05). Butyrate concentration also increased while acetate:propionate ratio and pH decreased with the addition of FEE (p < .05). These results indicated that the use of fibrolytic enzymes can be a reliable strategy to improve degradability of low-quality forages, contributing to the sustainability and intensification of livestock production in tropical countries.

Effects of forage feeding versus grain feeding on the growth performance and meat quality of Yangzhou geese.

1. Highly palatable and nutritious meat products can be produced through dietary interventions. Previous studies have shown that forage feeding has a significant impact on the growth performance and nutrition of cattle in various regions, but whether the same effects can be induced in geese remains unclear. 2. Three hundred and sixty Yangzhou goslings were divided according to body weight at 29 d old, assigned to one of 4 treatments and raised in separate pens. The treatments applied were (A) grazing, (B) grazing, grain supplemental diet (64 to 70 d), (C) grazing, grain supplemental diet and (D) confined. 3. Eviscerated carcass yield was lower in the grazing treatment. Protein content and muscle collagen in both the breast and thigh muscles were significantly higher in the grazing treatment than the confined, while fat content exhibited the opposite tendency. Those fed on grass and supplementary grain had a higher Mg and Cu content in breast muscle. 4. Geese will grow to their full potential when they are allowed to consume grass from pasture supplemented with grain, protein, collagen, Mg and Cu content was greater to a degree, which suggests this feeding regime is an ideal model for goose production.

Short communication: Relationship of activity and rumination to abundance of pest flies among organically certified cows fed 3 levels of concentrate.

The objectives of this study were to evaluate activity, rumination time, and their association with 3 kinds of pasture flies for organic dairy cows (n=57) fed 3 grain supplementation strategies during the grazing season from May to September 2013. Cows were assigned to 1 of 3 replicate supplementation groups: (1) no corn-grain supplementation (100% pasture, PAS, n=19); (2) low corn-grain (2.72kg/cow per day, LG, n=19); and (3) high corn-grain (5.44kg/cow per day, HG, n=19). Cows calved during 2 seasons (fall and spring) at the University of Minnesota West Central Research and Outreach Center, Morris, from October to December 2012 and March to May 2013. Supplement (corn-grain and minerals) was fed in a total mixed ration of corn silage and alfalfa silage, and at least 30% of diet dry matter intake for LG and HG cows consisted of pasture. Activity and rumination time (daily and 2-h blocks of time) were monitored electronically using HR-LD tags (SCR Engineers Ltd., Netanya, Israel) for 125d. Activity (cow body movement and head movement) was reported in activity units from SCR DataFlow II software, and rumination times were reported in minutes per day. PROC HPMIXED in SAS (SAS Institute Inc., Cary, NC) was used for statistical analysis, and independent variables were season of calving (fall or spring), month of grazing (June to September), supplementation group, and interactions of month of grazing and supplementation group. Replicate was a random effect with repeated measures. Daily activity was higher for PAS cows (1,138 activity units) than for HG cows (1,001 activity units), and LG cows (1,019 activity units). Daily activity was highest in July (1,258 activity units) and lowest in September (819 activity units). Rumination was not different for PAS (397min/d), LG (384min/d), or HG (370min/d) cows. Daily rumination was greater in September (402min/d) than in July (361min/d). Daily activity increased rapidly between 0600-0800h and 1600-1800h. From 1800 to 2000h, cows had a rapid decline in activity until 0600h the next day. All supplementation groups had the greatest rumination activity from 0200 to 0400h and the least between 1000 and 1200h. Greater activity of cows on a herd basis was moderately correlated with increased fly populations. Monthly activity patterns of grazing cows were associated with fly populations on cows.

Fatty acid profiles, meat quality, and sensory attributes of organic versus conventional dairy beef steers.

Meat from Holstein and crossbred organic and conventional dairy steers were evaluated and compared for fatty acid profiles, meat quality, sensory attributes, and consumer acceptance. Bull calves (n=49) were randomly assigned to 1 of 3 replicated groups: conventional (CONV), organic (ORG, pasture + concentrate), or grass-fed organic (GRS) and were born at the University of Minnesota West Central Research and Outreach Center (Morris, MN) between March and May 2011. The CONV steers (n=16) were fed a diet that contained 80% concentrate and 20% forage, and ORG steers (n=16) were fed a diet of organic corn, organic corn silage, and organic protein supplement. Furthermore, ORG steers consumed at least 30% of diet dry matter of high-quality organic pasture during the grazing season. The GRS steers (n=17) consumed 100% forage from pasture during the grazing season and high-quality hay or hay silage during the nongrazing season. The ORG steers had fat that was greater in oleic acid (C18:1) than the GRS and CONV steers (47.1, 36.1, and 39.9%, respectively). The GRS steers (21.9%) were lower for monounsaturated fat than the ORG (42.1%) and CONV (40.4%) steers. Furthermore, the GRS steers tended to have greater n-3 fat and had lower n-6 fat than the ORG and CONV steers. Consequently, the GRS (1.4%) steers had a lower n-6-to-n-3 fat ratio than the ORG (12.9%) and CONV (10.0%) steers. The GRS (2.6 kg) steers had steaks that were not different for Warner-Bratzler shear force than ORG (2.3 kg) steaks; however, the GRS steaks tended to have greater shear force than the CONV (2.0 kg) steaks. The 3 steer group had steaks that were not different for color brightness (L*; 0 = black and 100 = white) and yellowness/blueness (b*; positive values = yellow and negative values = blue) values; however, the GRS (10.5) steaks had lower redness/greenness (a*; positive values = red and negative values = green) values than CONV (14.5) steaks. For sensory attributes (0- to 120-point scale), no differences were observed for ORG (71.3) and CONV (69.2) steers for overall consumer liking of the beef; however, the GRS (56.3) steers had the lowest overall liking among beef consumers. The ORG (73.3) steers had greater flavor liking than the GRS (56.8) and CONV (69.2) steers. Conversely, the GRS (6.3) steers had the highest scores for off-flavor (0- to 20-point scale) compared with the ORG (3.9) and CONV (4.1) steers. The results of the current study suggest that a potential market may exist for organic grass-fed dairy steers in the United States, but quality and consistency of the beef needs to be improved.

Impact of feeding regimes and lactation stage on sensory attributes of Cheddar cheese.

This study investigated the effects of diet and stage of lactation (SOL) on sensory profiles, texture, volatile profiles, and colour of Cheddar cheese. Cheddar cheese was manufactured from early-, mid-, and late-lactation milk obtained from seasonally calved cows (n = 54). Cows were assigned a diet; group 1: perennial ryegrass (GRS), group 2: total mixed ration (TMR), and group 3: partial mixed ration (PMR). Instrumental analysis was performed at 270 days (mature Cheddar). Sensory evaluation took place after 548 days (extra mature Cheddar). Toluene was the only volatile compound that was significantly influenced by diet. The trained panel rated early-lactation cheese as stronger than mid- and late- for cowy/barny flavour and late-lactation cheese as sweeter than early- and mid-lactation cheese. Mid-lactation cheese was liked least overall. Early-lactation cheeses were rated higher for 'crumbly' texture than mid- and late. Diet affected consumer ratings, with GRS and PMR cheese rated as more intense than TMR for flavour, aftertaste, and saltiness. Consumers reported that TMR cheese was lighter in colour compared to GRS cheese, which was supported by instrumental analysis. Consumers perceived GRS as more springy and less crumbly than TMR and PMR, while Texture Profile Analysis indicated that TMR was harder than GRS. Consumer segmentation was observed with two clear preference groups, one preferring GRS and one preferring TMR. For both groups, 'taste' seemed to be the main driver of liking, highlighting that consumer preference is most impacted by individual taste preferences.

Metagenomic and metabolomic analyses reveal differences in rumen microbiota between grass- and grain-fed Sanhe heifers.

Introduction: The aim of this study was to investigate the effects of diets on the composition and function of rumen microbiome and metabolites in Sanhe heifers. Methods: Metagenomic and metabolomic analyses were performed using rumen fluid samples collected from Sanhe heifers (n = 20) with similar body weights and ages from grass-fed and grain-fed systems. Results: The grain-fed group exhibited more intensive rumen fermentation than the grass-fed group. However, the grass-fed group exhibited carbohydrate metabolism and methane production higher than that of the grain-fed group; these increases were observed as a higher abundance of various bacterial phyla (Firmicutes, Bacteroidetes, Actinobacteria, Lentisphaerae, and Verrucomicrobia), families (Lachnospiraceae, Eubacteriaceae, and Eggerthellaceae), and the archaeal family Methanobacteriaceae. A comparison of genes encoding carbohydrate-active enzymes, using Kyoto Encyclopedia of Genes and Genome profiles, revealed noteworthy differences in the functions of rumen microbiota; these differences were largely dependent on the feeding system. Conclusion: These results could help manipulate and regulate feed efficiency in Sanhe cattle.

Characterisation of Dry-Salted Violino and Bresaola from Grass-Fed Bergamasca Sheep.

This study focuses on characterising two seasoned products, violino and bresaola, derived from grass-fed Bergamasca sheep monitored with a GPS system. The evaluation includes both nutritional and sensory aspects. Results reveal that both products boast a high protein content (approximately 40%) and a beneficial fatty acid profile, endorsing a healthy n-6/n-3 ratio (2.2), along with rumenic acid (92-184 mg/100 g) and branched-chain fatty acids (BCFAs) (237-621 mg/100 g). The sensory evaluation highlights distinctive ovine characteristics in aroma and flavour. Violino and bresaola from grass-fed Bergamasca sheep showcase positive attributes for human consumption. The study emphasises the potential for added value to seasoned products from Bergamasca sheep through a traceable, sustainable, and health-conscious supply chain.

Combining sheep and beef cattle in a pasture-based system minorly influenced muscle and fat colour and dorsal fat firmness but increased fat skatole content in lambs.

A recent long-term system-level experiment, using grassland-based organic systems established as separate farmlets, showed that combining sheep and beef cattle within a mixed (MIX) system promoted self-sufficient production of grass-fed meat and improved economic and environmental performance in the sheep enterprise compared to a sheep-only (SH) system. In the present study, we used all male lambs produced over the first year in this experiment to evaluate the effect of this farming practice on some lamb carcass and meat sensory quality traits. Lambing took place at the end of February and lambs were pasture-fed from 1 month of age on average until slaughter, unless they were not ready for slaughter at 3-4 weeks before the start of the mating period in October, in which case they were finished indoors on a concentrate-based diet. All MIX lambs (n = 33) were finished at pasture. One SH lamb (out of a total of 85) had to be finished indoors with a concentrate-based diet. MIX lambs had a higher growth rate than SH lambs (P < 0.001), resulting in a lower lamb age at slaughter in MIX than in SH (150 vs 173 days, P < 0.001). Carcass weight and degree of fatness, kidney fat weight and dorsal fat thickness did not differ between systems. Kidney fat skatole concentration was higher in MIX than in SH (median value reaching 0.15 µg/g liquid fat and 0.11 µg/g liquid fat in MIX and SH, respectively, P < 0.05). This was most likely due to MIX lambs being slaughtered at a younger age and therefore eating younger grass. There were minor differences between MIX and SH lambs in dorsal fat firmness and in colour coordinates of longissimus thoracis et lumborum muscle. We conclude that while combining sheep and beef cattle within a mixed system offers advantages in terms of self-sufficient production of grass-fed meat and system economic and environmental performance, it could come at a cost to lamb flavour.

Predicting Carcass Weight of Grass-Fed Beef Cattle before Slaughter Using Statistical Modelling.

Gaining insights into the utilization of farm-level data for decision-making within the beef industry is vital for improving production and profitability. In this study, we present a statistical model to predict the carcass weight (CW) of grass-fed beef cattle at different stages before slaughter using historical cattle data. Models were developed using two approaches: boosted regression trees and multiple linear regression. A sample of 2995 grass-fed beef cattle from 3 major properties in Northern Australia was used in the modeling. Four timespans prior to the slaughter, i.e., 1 month, 3 months, 9-10 months, and at weaning, were considered in the predictive modelling. Seven predictors, i.e., weaning weight, weight gain since weaning to each stage before slaughter, time since weaning to each stage before slaughter, breed, sex, weaning season (wet and dry), and property, were used as the potential predictors of the CW. To assess the predictive performance in each scenario, a test set which was not used to train the models was utilized. The results showed that the CW of the cattle was strongly associated with the animal's body weight at each stage before slaughter. The results showed that the CW can be predicted with a mean absolute percentage error (MAPE) of 4% (~12-16 kg) at three months before slaughter. The predictive error increased gradually when moving away from the slaughter date, e.g., the prediction error at weaning was ~8% (~20-25 kg). The overall predictive performances of the two statistical approaches was approximately similar, and neither of the models substantially outperformed each other. Predicting the CW in advance of slaughter may allow farmers to adequately prepare for forthcoming needs at the farm level, such as changing husbandry practices, control inventory, and estimate price return, thus allowing them to maximize the profitability of the industry.

Pasture-finishing of bison improves animal metabolic health and potential health-promoting compounds in meat.

BACKGROUND: With rising concerns regarding the effects of red meat on human and environmental health, a growing number of livestock producers are exploring ways to improve production systems. A promising avenue includes agro-ecological practices such as rotational grazing of locally adapted ruminants. Additionally, growing consumer interest in pasture-finished meat (i.e., grass-fed) has raised questions about its nutritional composition. Thus, the goal of this study was to determine the impact of two common finishing systems in North American bison-pasture-finished or pen-finished on concentrates for 146 d-on metabolomic, lipidomic, and fatty acid profiles of striploins (M. longissimus lumborum). RESULTS: Six hundred and seventy-one (671) out of 1570 profiled compounds (43%) differed between pasture- and pen-finished conditions (n = 20 animals per group) (all, P < 0.05). Relative to pasture-finished animals, the muscle of pen-finished animals displayed elevated glucose metabolites (~ 1.6-fold), triglycerides (~ 2-fold), markers of oxidative stress (~ 1.5-fold), and proteolysis (~ 1.2-fold). In contrast, pasture-finished animals displayed improved mitochondrial (~ 1.3-fold higher levels of various Krebs cycle metabolites) and carnitine metabolism (~ 3-fold higher levels of long-chain acyl carnitines) (all P < 0.05). Pasture-finishing also concentrated higher levels of phenolics (~ 2.3-fold), alpha-tocopherol (~ 5.8-fold), carotene (~ 2.0-fold), and very long-chain fatty acids (~ 1.3-fold) in their meat, while having lower levels of a common advanced lipoxidation (4-hydroxy-nonenal-glutathione; ~ 2-fold) and glycation end-product (N6-carboxymethyllysine; ~ 1.7-fold) (all P < 0.05). In contrast, vitamins B5, B6, and C, gamma/beta-tocopherol, and three phenolics commonly found in alfalfa were ~ 2.5-fold higher in pen-finished animals (all P < 0.05); suggesting some concentrate feeding, or grazing plants rich in those compounds, may be beneficial. CONCLUSIONS: Pasture-finishing (i.e., grass-fed) broadly improves bison metabolic health and accumulates additional potential health-promoting compounds in their meat compared to concentrate finishing in confinement (i.e., pen-finished). Our data, however, does not indicate that meat from pen-finished bison is therefore unhealthy. The studied bison meat-irrespective of finishing practice-contained favorable omega 6:3 ratios (< 3.2), and amino acid and vitamin profiles. Our study represents one of the deepest meat profiling studies to date (> 1500 unique compounds), having revealed previously unrecognized differences in animal metabolic health and nutritional composition because of finishing mode. Whether observed nutritional differences have an appreciable effect on human health remains to be determined.

Combining beef cattle and sheep in an organic system. II. Benefits for economic and environmental performance.

Combining several animal species to optimise the performance of the whole farming system is one of the core tenets of agroecology. Here, we associated sheep with beef cattle (40-60% livestock units (LU)) in a mixed system (MIXsys) and compared its performances to those of a specialised beef cattle-only system (CATsys) and a specialised sheep-only system (SHsys). All three systems were designed to have identical annual stocking rates and similar farm areas, pastures and animals. The experiment was conducted for four campaigns (2017-2020) in an upland setting exclusively on permanent grassland under certified-organic farming standards. The young animals were fattened almost exclusively with forages: at pasture for lambs and indoors with haylage in winter for young cattle. Abnormally dry weather conditions led to hay purchases. We compared between-system and between-enterprise performances based on technical, economic (gross product, expenses, margins, income), environmental (greenhouse gas emissions (GHG), energy consumption) and feed-food competition balance indicators. The mixed-species association only benefited the sheep enterprise, with +17.1% meat production per LU (P < 0.03), -17.8% concentrate used per LU (P < 0.02), +10.0% gross margin (P < 0.07) and +47.5% income per LU (P < 0.03) in MIXsys vs SHsys, as well as environmental performance benefits via a reduction of 10.9% in GHG emissions (P < 0.09) and 15.7% in energy consumption (P < 0.03), and a 47.2% improvement in feed-food competition (P < 0.01) in MIXsys vs SHsys. These results are due to both better animal performance and lower concentrate consumption in MIXsys, as presented in a companion paper. These benefits outweighed the additional costs of the mixed system, especially for fencing, in terms of net income per sheep LU. There were no between-system differences in productive and economic performance (kilos live-weight produced, kilos concentrate used and income per LU) for the beef cattle enterprise. Despite good animal performances, the beef cattle enterprises in both CATsys and MIXsys had poor economic performance due to large purchases of conserved forages and difficulty selling the animals, which were ill-adapted to the traditional downstream sector. This multiyear study at the farming-system level, which has thus far been underresearched for mixed livestock farming systems, highlighted and quantified the benefits for sheep when combined with beef cattle on economic, environmental, and feed-food competition performance.

Comparing consumer liking of beef from three feeding systems using a combination of traditional and temporal liking sensory methods.

Research on the effects of animal diet on consumer liking of beef has yielded conflicting results. Currently it is unknown whether dynamic changes occur in liking during consumption of beef. This study applied a combination of traditional and temporal (free and structured) liking methods to determine consumer liking of beef derived from animals that were fed grain (GF), grass silage plus grain (SG) or grazed grass (GG) during finishing. Three separate panels of beef eating consumers (n = 51; n = 52; n = 50) were recruited from Teagasc Food Research Centre, Dublin, Ireland to assess striploin steaks from animals fed either GF, SG, or GG. Using the free temporal liking (TL) method, results revealed that beef from GF animals was liked significantly less (p ≤ 0.05) in terms of overall liking, tenderness and juiciness, when compared to steaks from the SG and GG animals. These effects were not observed using the structured TL or traditional liking methods. Further analysis showed the evolution of scores over time was significant (p ≤ 0.05) for all attributes using the free TL method. Overall, the free TL method yielded more discriminative data and was perceived as easier to perform by consumers compared to the structured TL method. These results show that the free TL method may provide an opportunity to elicit more in-depth information regarding consumer sensory response to meat.