Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils

Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D’ Aquitaine steers (average BW=293.7±38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 (P<0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio (P<0.05), OLI had the highest content of t11-18:1 (P<0.01) and c9,t11-18:2 (P<0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) (P<0.001), the highest percentage of PUFA (P<0.01) and a lower index of atherogenicity (P=0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.     

Reliability of map accuracy assessments: A reply to Roff et al. (2016)

Roff et al. (Ecological Management and Restoration, 17 , 2016, 000) provide a discussion of the criteria expected for the best approach to validation of mapping programs and uses Hunter (Ecological Management & Restoration 17 , 2016, 40) to highlight issues involved. While we support the general principles outlined, we note that the review does not apply the same standards to Sivertsen et al. (Greater Hunter Native Vegetation Mapping Geodatabase Guide (Version 4.0). Office of Environment and Heritage, Department of the Premier and Cabinet, Sydney, Australia, 2011), the original document critiqued by Hunter (Ecological Management & Restoration 17 , 2016, 40). The Hunter (Ecological Management & Restoration 17 , 2016, 40) validation was based on a larger sample size, greater sampling within mapping units and greater representation of landscapes than Sivertsen et al. (Greater Hunter Native Vegetation Mapping Geodatabase Guide (Version 4.0). Office of Environment and Heritage, Department of the Premier and Cabinet, Sydney, Australia, 2011). Survey and validation sites being placed along public roads and lands are common to both the general Office of Environment and Heritage (OEH) and Hunter (Ecological Management & Restoration 17 , 2016, 40) validation methodologies. Thus, the criticisms of Roff et al. (Ecological Management and Restoration, 17 , 2016, 000) of the Hunter (Ecological Management & Restoration 17 , 2016, 40) approach apply equally, if not more, to Sivertsen et al. (Greater Hunter Native Vegetation Mapping Geodatabase Guide (Version 4.0). Office of Environment and Heritage, Department of the Premier and Cabinet, Sydney, Australia, 2011). We outline in the article how the Roff et al. (Ecological Management and Restoration, 17 , 2016, 000) critique was selective and in some cases incorrect in its analysis of issues presented in Hunter (Ecological Management & Restoration 17 , 2016, 40) and did not apply the same criteria to their own work. We conclude by discussing future directions for validating and mapping vegetation communities.     

Interannual variability,stability and resilience in UK plant communities

Plant communities are often assumed to be stable on a year-to-year basis. We present evidence that species composition in permanent quadrats changes considerably between years at a range of Environmental Change Network sites across the UK. The extent of this variability varies with habitat type. Communities associated with low disturbance levels and low agricultural inputs, particularly moorland (upland grass and heath) and bog communities, are most stable.Inter-annual variability should, therefore, be considered in designing monitoring schemes to ensure that frequency of recording is sufficient to avoid short-term fluctuations obscuring long-term trends.More diverse communities were more stable, with less species turnover between years. However, diverse communities also tended to be dominated by slow-growing, slow-reproducing plants, adapted to low nutrient conditions, identified as ‘stress tolerators’ in the Grime CSR scheme and low Ellenberg N values. Species compositional stability was more strongly correlated with these indices of plant functional types than species richness. Nevertheless, a significant effect of species richness could be identified, even after other causes of variation were accounted for.More stable communities in our study are likely to be resilient to low levels of environmental change, although they may still change, and possibly change dramatically if critical ‘tipping points’ are reached.     

Going feral: Wild meat consumption and the uncanny in Melbourne,Australia

Feral animals are commonly constructed as the scourge of the Australian landscape. The transgressive act of introduced, domestic animals going wild elicits strong emotive responses within the community, often conceived in a kind of Freudian spectre of das unheimliche (the uncanny/unhomely), as the once familiar becomes uncontrolled, strange and frightening. Meanwhile, exponential global growth in human populations, and the resulting strain on the environment and food security, is necessitating the rethinking of meat consumption. In Australia, while the stigma surrounding feral animals has historically inhibited their consumption, feral meat is regarded by a growing body of advocates as an environmentally favourable alternative to farmed meat, allowing not only the avoidance of animal suffering within the industrial agriculture model, but also benefitting ecosystems through the removal of damage‐wreaking interlopers. This paper explores the feral turn and its contemporary manifestations as a growing food movement in Melbourne.     

Identification of Polymorphisms in the Rabbit Growth Hormone Receptor (GHR) Gene and Association with Finishing Weight in a Commercial Meat Rabbit Line

A shortcut to identify DNA markers associated with economic traits is to use a candidate gene approach that is still useful in livestock species in which molecular tools and resources are not advanced or not well developed. Mutations in the growth hormone receptor (GHR) gene associated with production traits have been already described in several livestock species. For this reason GHR could be an interesting candidate gene in the rabbit. In this study we re-sequenced all exons and non-coding regions of the rabbit GHR gene in a panel of 10 different rabbits and identified 10 single nucleotide polymorphisms (SNPs). One of them (g.63453192C>G or c.106C>G), located in exon 3 was a missense mutation (p.L36V) substituting an amino acid in a highly conserved position across all mammals. This mutation was genotyped in 297 performance tested rabbits of a meat male line and association analysis showed that the investigated SNP was associated with weight at 70 days (P < 0.05). The most frequent genotype (GG) was in animals with higher weight at this age, suggesting that the high directional selection pressure toward this trait since the constitution of the genotyped line might have contributed to shape allele frequencies at this polymorphic site.     

The effect of polyphenols and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature

The aim of this study was to determine the effect of a polyphenol product (PP) (Proviox) and vitamin E on the antioxidant status and meat quality of broiler chickens exposed to high temperature. The experimental materials comprised 120 ROSS 308 broilers (6 treatments, 10 replications, 2 birds per replication). Dietary supplementation with vitamin E and PP was applied in the following experimental design: group I (negative control) – without supplementation; group II (positive control) – without supplementation; group III – supplementation with 100 mg vitamin E/kg; group IV – 200 mg vitamin E/kg; group V – 100 mg vitamin E/kg and 100 mg PP/kg; group VI – 200 mg PP/kg. In groups II–VI, broiler chickens aged 21–35 d were exposed to increased temperature (34°C for 10 h daily). In chickens exposed to high temperature, dietary supplementation with antioxidants, mostly PP, improved growth performance parameters, including body weight, body weight gain and feed intake until 28 d of age. Vitamin E added to broiler chicken diets at 200 mg/kg and vitamin E combined with PP was most effective in improving the total antioxidant status of birds, enhancing blood antioxidant enzyme activities and increasing vitamin E concentrations in the liver and breast muscles. Broilers fed diets supplemented with 200 mg/kg of vitamin E alone and vitamin E in combination with PP were characterised by a higher percentage content of breast muscles in the carcass. Dietary supplementation with antioxidants improved the water-holding capacity of meat, reduced natural drip loss and increased the crude ash content of meat. The breast muscles of chickens fed diets supplemented with PP had a lower contribution of yellowness. The breast muscles of chickens receiving diets with 100 mg vitamin E/kg(group III) and diets supplemented with PP (groups V and VI) were characterised by the highest concentrations of polyunsaturated fatty acids. The PP can be a valuable component of diets for broiler chickens exposed to high temperature.     

Meat quality of farmed red deer fed a balanced diet: effects of supplementation with copper bolus on different muscles

Supplementation with copper (Cu) improves deer antler characteristics, but it could modify meat quality and increase its Cu content to levels potentially harmful for humans. Here, we studied the effects of Cu bolus supplementation by means on quality and composition of sternocephalicus (ST) and rectus abdominis (RA) muscles (n=13 for each one) from yearling male red deer fed with a balanced diet. Each intraruminal bolus, containing 3.4 g of Cu, was administered orally in the treatment group to compare with the control group. Meat traits studied were pH at 24 h postmortem (pH₂₄), colour, chemical composition, cholesterol content, fatty acid (FA) composition, amino acid (AA) profile and mineral content. In addition, the effect of Cu supplementation on mineral composition of liver and serum (at 0 and 90 days of treatment) was analysed. No interactions between Cu supplementation and muscle were observed for any trait. Supplementation with Cu increased the protein content of meat (P<0.01). However, Cu content of meat, liver and serum was not modified by supplementation. In fact, Cu content of meat (1.20 and 1.34 mg/kg for Cu supplemented and control deer, respectively) was much lower in both groups than 5 mg/kg of fresh weight allowed legally for food of animal origin. However, bolus of Cu tended to increase the meat content of zinc and significantly increased (P<0.05) the hepatic contents of sodium and lead. Muscles studied had different composition and characteristics. The RA muscle had significantly higher protein content (P<0.001), monounsaturated FA content (P<0.05) and essential/non-essential AA ratio (P<0.01) but lower pH₂₄ (P<0.01) and polyunsaturated FA content (P=0.001) than the ST muscle. In addition, RA muscle had 14.4% less cholesterol (P=0.001) than ST muscle. Also, mineral profile differed between muscles with higher content of iron, significantly higher (P<0.001) content of zinc and lower content of calcium, magnesium and phosphorus (P<0.05) for ST muscle compared with RA. Therefore, supplementation with Cu modified deer meat characteristics, but it did not increase its concentration to toxic levels, making it a safe practice from this perspective. Despite the lower content of polyunsaturated FA, quality was better for RA than for ST muscle based on its higher content of protein with more essential/non-essential AA ratio and lower pH₂₄ and cholesterol content.     

Water footprint assessment of sheep farming systems based on farm survey data

Water scarcity is among the main challenges making vulnerable the livestock farming systems in drylands. The water footprint (WF) indicator was proposed as a metric to measure the impacts of livestock production on freshwater resources. Therefore, this study aimed to assess water use in five different Tunisian sheep production systems using the Water Footprint Network methodology. The primary data were obtained from 1050 sheep farms located in 13 Tunisian provinces. A multivariate analysis was performed to characterize the different farming systems. A validation step of the WF modeled values of sheep meat was conducted in 12 sheep farms belonging to two different farming systems. This was done through year-round monitoring of on-farm practices using water metres and recording equipment’s taking into account the direct and indirect water use. The typology analysis came up with five sheep farming systems that are the mixed sheep-cereal (MSC), the agro-sylvo-pastoral (ASP), the agro-pastoral (AP), the extensive agro-pastoral (EAP) and the mixed sheep-olive tree farming systems. The WF of sheep meat produced under the target farming systems ranged from 8654 to 13 056 l/kg live weight. The evaluation of WF of five different sheep production systems figured out that sheep raised under the EAP farming system had the greatest WF per ton of live animal. However, the ASP farming system exhibited the lowest WF. Water used to grow feedstuffs for sheep production accounts for 98% of the total WF of sheep. The green WF accounts for more than 92% of the total WF in all farming systems. Results of monitoring water use at farm scale show that the modeled values of WF are overestimated by an average of 23.3% and 24.1% for the selected farms assigned to the MSC and AP farming systems, respectively. Water use for sheep production is high in most of the Tunisian farms. Therefore, the general assumption that ‘meat production is a driver of water scarcity’ is supported and should be considered as an important focal point in agricultural and water policies. Particular attention should be given to forage crops with low WFs and high contribution to dry matter to provide ration with low WF. The efficient use of green water along the meat value chain is essential to minimize the depletion of blue water resources and to reduce the economic dependency on virtual water through the import of feedstuffs.