An increasing number of consumers are expressing concerns about the quality, nutrient content, and safety of the meet products they purchase, alongside animal welfare and the environmental footprint of production systems. Various studies show that grassland-based systems can produce a healthier meat product. In this context, livestock farmers are actively pursuing improvements in their systems focus on sustainability, with regenerative livestock farming emerging as a prominent approach. Most research has focused on showing the differences in the quality of meat comparing pastoral systems and those fed concentrates under controlled environments. However, there are no studies in Chile that evaluate the quality of beef derived from different pastoral systems, particularly those consider adequate data and products sourced directly from livestock sector. This study explores three beef production systems commonly used in southern Chile (conventional, free grazing, and regenerative), evaluating their impact on carcass characteristics, meat quality attributes, and nutritional components. The results show some variations in carcass weight and yield, with free grazing showing better results. Deviations in meat color were observed, with conventional meat being more red and yellow while regenerative meat was less bright. Subcutaneous fat color and water retention capacity were influenced by diet and production methods. Although lipid oxidation showed no differences, 100% grazing-based systems exhibited lower values, suggesting a higher intake of antioxidants. The research highlights the nutritional superiority of beef from grasslands, characterized by a lower intramuscular fat content and higher values of minerals, such as selenium. The complex multifactorial interaction of pastoral systems is also highlighted, impacting the carcass and meat quality. A holistic approach is essential in future research to generate and assess healthy beef.

Zinc (Zn) is widely known as an essential trace element for fish and new ways to supply it to them are needed. Palygorskite (Pal) is a natural silicate clay mineral and the palygorskite structure contains nano-channels, which are filled with water and exchangeable ions. Zn-bearing palygorskites (Zn-Pal) prepared using ion exchange have attracted attention due to the durable antibacterial properties that limit pathogens and as a potential new Zn source for livestock. The present study was conducted to evaluate the effects of Zn-Pal supplementation on the growth performance, nutrient retention, meat quality, Zn accumulation, and intestinal Zn transporter protein gene expression in blunt snout bream Megalobrama amblycephala. The fish were fed a basal diet without an exogenous Zn source and the basal diet was supplemented with 125 mg/kg Zn as Zn sulfate (ZnSO4) or 35, 80, or 125 mg/kg Zn as Zn-Pal. Each diet was tested using three replicates for 7 weeks. The results showed that dietary Zn-Pal supplementation quadratically (P<0.05) increased growth performance, nutrient retention, total and Cu/Zn superoxide dismutase activity, Zn content in scales, and intestinal Zn transporter protein gene expression. The muscular cooking loss in blunt snout bream decreased with the optimum Zn-Pal Zn level of 35 mg/kg. Compared to the fish treated with ZnSO4, the fish supplemented with 35 mg/kg as Zn-Pal exhibited similar growth performance and nutrient retention (P>0.05), increased mRNA expression of the metal-response element-binding transcription factor-1 in the intestine (P<0.05), and decreased cooking loss of muscle (P<0.05).The results suggested that 35 mg/kg Zn supplementation as Zn-Pal could improve the growth performance and body composition, increase nutrient retention and tissue Zn concentrations, enhance the muscle water-holding capacity, and enhance antioxidant status in blunt snout bream. The Zn-Pal was more efficient and could be used as an alternative Zn source to ZnSO4 in the diet of blunt snout bream.

An experiment was conducted to investigate the incidence of travel sickness in pigs, specific hormone concentrations at exsanguination and subsequent meat quality. Fifty, 80kg slaughter pigs were transported on a lorry for 4.5h. During the journey, behavioural observations of the individually marked pigs were made by scanning every 8min to establish whether the pigs exhibited certain symptoms of travel sickness (foaming at the mouth and chomping) and incidences of retching and vomiting were noted as they occurred. Upon arrival at the slaughterhouse, pigs were unloaded, slaughtered immediately and a blood sample was taken at exsanguination for analysis of plasma Cortisol, beta-endorphin and lysine vasopressin concentrations. On the day following slaughter, the chilled carcase of each pig was assessed for meat quality (using pH, Fibre Optic Probe, and Tecpro Pork Quality Meter measurements) in the longissimus dorsi, semimembranosus and adductor muscles to determine the incidence of PSE (pale, soft, exudative) or DFD (dark, firm, dry) meat quality. Twenty-six per cent of the pigs (a total of 13 individuals) vomited or retched during the journey. There was no relationship between the incidence of travel sickness and either the concentrations of the hormones analysed at exsanguination or subsequent meat quality. Correlations revealed no significant relationship between concentrations of the hormones and meat quality measurements.

Methods for culling wild red deer (Cervus elaphus) were compared by observing behaviour and collecting post mortem samples from wild deer shot: (i) by a single stalker during daytime; (ii) by more than one stalker during daytime; (iii) by using a helicopter for the deployment of stalkers and carcase extraction; or (iv) by a single stalker at night, and compared with farmed red deer shot in a field or killed at a slaughterhouse. Culling by a single stalker during the day and shooting in a field were the most accurate in achieving placement of a shot in a target area, but when compared across all methods, there were no significant differences in the percentages of deer that were either wounded or appeared to have died immediately after the first shot. Plasma cortisol concentrations in deer shot using helicopter assistance were similar to those in deer at the slaughterhouse, but higher than deer shot at night or during the day by a single stalker, or in a field. Deer shot using helicopter assistance and also deer culled by a collaborative and single stalking during the day had lower muscle glycogen concentrations than those culled by a single stalker at night. There was no evidence that a particular culling method was associated with an increased risk of accidental or pre-culling injury. If a helicopter is used to assist culling, the deer are more likely to be disturbed before they are shot and therefore, measures should be taken to minimise the disturbance to the deer.

Given the multi-dimensionality of animal welfare, any monitoring system for slaughter animals should comprise an integrative vision that facilitates animal welfare and food safety assessment. Thus, the aim of this study was to investigate risk factors as possible causes for liver condemnations, hoof disorders, bruise prevalence, and the quality of beef carcases under commercial operating conditions in Mexico. Data were recorded for 143 journeys encompassing 1,040 commercial cattle, originating from feedlots, free-range, and dairy production systems. Details on journey distance, vehicle type, cattle type, and animals’ origin were gathered from abattoir reports. We found that carcase bruising (41%) and hoof disorders (43.9%) had the highest prevalence, regardless of the production system. Variables such as cattle type and production system influenced liver condemnations; old bulls extensively raised were more prone to present parasitosis such as Fasciola hepatica. Transportation conditions (journey distance, vehicle type) and cattle type might have influenced the development of hoof disorders in the evaluated animals. Multivariable logistic regression showed that animals’ origin was a potential risk factor for severe bruising and high muscle pH, with cull dairy cows getting the most serious damage. In general, cattle transport conditions were factors that showed interactions with three of the evaluated indicators (severe hoof injuries, carcase bruising, meat pH24h). Our study shows the need to implement integrative surveillance to identify risk factors according to the production system from which the animals originate. With this information it is possible to develop strategies to mitigate specific cattle welfare problems.

During slaughter, cattle may be exposed to many potentially stress-inducing factors, of emotional and physical nature. A series of studies aimed to identify factors that may contribute to slaughter stress. During reactivity tests testing emotional stressors, Blond d’Aquitaine bulls were more reactive than Angus and Limousin bulls. However, no breed differences were found for stress indicators at slaughter. Indicators of post mortem (PM) muscle metabolism were correlated with stress reactions at slaughter, and with behavioural reactions and heart rates during the reactivity tests, including a sudden event and handling. Similarly, in Normand cull cows, stronger behavioural and physiological reactions during the slaughter procedure were associated with faster PM muscle metabolism. Reactions during the reactivity tests were also correlated with stress indicators at slaughter. A Principal Component Analysis indicated that the first and second axes were correlated with reactions to non-familiarity and to social isolation, respectively. Both axes were correlated with stress indicators at slaughter, suggesting that these two aspects contribute significantly to the emotional stress at slaughter. These experiments indicate that stress reactivity at slaughter may be predicted from behavioural and emotional stress reactions during reactivity tests. A third experiment found that compared with normally fed cows, 30-h food-deprived cows showed stronger startle and fear responses in response to a sudden event. Within a group subjected to a physical-effort treatment, compared to normally fed heifers, food-deprived heifers were more reactive to human exposure. This shows that the reactions to a given stressor may increase due to the presence of other stressors. Thus, in cattle, novelty, social disturbances and sudden events may contribute to slaughter stress and the simultaneous presence of several stressors during the slaughter period may exacerbate stress reactions.

Rapid analysis of animal welfare is a crucial component of the assessment of the meat quality supply chain, ensuring management procedures confer optimum standards of welfare. Further, there is increasing interest in monitoring the welfare state of each individual animal. This study looked at transport and pre-slaughter management in terms of meat quality evaluated in two breeds (Biellese and Sambucana) across two different farming systems. Precision Livestock Farming (PLF) technologies were implemented, including accelerometer and rumination activity ear-tag sensors, as potential welfare indicators during transportation and pre-slaughter. Significant correlations were found between sensors’ parameters, such as total activity and rumination and physical and chemical meat quality characteristics such as drip loss. Lambs with lower rumination and/or lower total activity were found to have lower drip loss indicating reduced meat quality. Sensors have the potential to help detect those animals particularly sensitive to stressors during transport and pre-slaughter handling and may allow real-time measurement of the impact of transport and handling in abattoirs, enabling better animal management via specific customised strategies.

Meat quality is not only influenced by breed but also rearing environment. The aim of this study was to evaluate the influence of different housing environments on growth performance, carcase traits, meat quality, physiological response pre-slaughter and fatty acid composition in two pig breeds. A total of 120 growing pigs at 60-70 days of age were arranged in a 2 × 2 factorial design with the breeds (Duroc × Landrace × Large White [D × L × LW] and Duroc × Landrace × Min pig [D × L × M]) and environmental enrichment (barren concrete floor or enriched with straw bedding) as factors. Each treatment was performed in triplicate with ten pigs per replicate. The pigs housed in the enriched environment exhibited a higher average daily gain, average daily feed intake, saturated fatty acid percentage and backfat depth than the pigs reared in the barren environment. Plasma cortisol levels were lower and growth hormone higher in enriched compared to barren pens. The D × L × M pigs showed lower cooking loss compared with the D × L × LW pigs. Moreover, the D × L × M pigs exhibited poor growth performance but had a better water-holding capacity. Only carcase traits and meat quality interaction effects were observed. We concluded that an enriched environment can reduce preslaughter stress and improve the growth performance of pigs and modulate the fatty acid composition of pork products.

The objective of this study was to evaluate conditions during transport and their effects on welfare and carcase bruising of beef cattle in Uruguay, a country with an extensive, pasture-based, production system. Twelve abattoirs were visited periodically during two years (2002-2003) and 448 trucks were inspected on arrival. The state of vehicle maintenance was deemed ‘unacceptable’ for the transport of animals in 16.5 (± 3.2)% of cases and most of the vehicles (99.1 [± 0.1]%) had a ‘guillotine-type’ door at the rear end. Both characteristics showed a significant association with the presence of carcase bruising. No overall significant difference was found with the year of vehicle manufacture (24.6 [± 0.2]% before 1990), the presence of rollers bars in 51.3 (± 0.1)% of the trucks on one or both sides of the doors, and the working experience of the men who transported the cattle (> 10 years). The average distance travelled with the animals loaded onto trucks was 240 (± 9) km and the mean journey length was 305 (± 7) min (5 h). A statistically significant effect of the distance travelled and the state of the roads on the occurrence of bruising was found. The use of devices to force animals to move, such as: electric prod (75%), sticks (3%), loud shouts (40%) and a combination of all of the above were positively correlated with bruising. After slaughter, carcase bruising was identified, quantified, and classified into three degrees of muscle injury. From 15,168 beef cattle observed, 60.0% (9,106) had at least one injury. Of the injured carcases, 33.1% (3,015) had one bruise, 25.1% (2,289) had two bruises, 16.2% (1,474) had three bruises and 25.6% (2,328) four or more bruises. Transporting animals in a humane fashion will reduce the amount of bruising on carcases, thereby increasing both the welfare of beef cattle and the profitability of the beef industry in Uruguay.

Pork is one of the most consumed meats worldwide, yet, pork quality remains an issue for the industry, mainly because of flavour, colour and water holding capacity instabilities. Castration techniques combined with dietary supplementation with ractopamine hydrochloride (RAC) seem to be a tangible solution to deal with these issues. There is a lack of knowledge of how these techniques will impact the proteomic profile and, consequently, the meat quality. The main goal of this work was to study the proteomic profile of non-aged pork meat under different sexual conditions and RAC dietary supplementation, and how the combination of these two factors impacts meat quality attributes. Forty-eight animals were distributed in six treatments, three sexual conditions (females; surgically castrated males; immune castrated males) and two diets (with RAC inclusion or without). For proteomic analysis, a sample of the Longissimus dorsi muscle was collected 24 h after slaughter and analysed using one-dimensional SDS/PAGE. The ultimate pH and colour (L*, a*, b*) were measured in the carcasses after 24 h, then meat samples were collected to measure drip, cooking and thawing losses, as well as the shear force. The interaction between gender and diet affected the ultimate pH and the L* parameter. Meat tenderness was only influenced by diet. Twenty-seven protein bands were revealed by SDS/PAGE, six of them with the protein abundance affected by diet. In conclusion, the inclusion of dietary RAC caused differences in the pork meat proteome, and more studies are necessary to fully explore the proteins involved in these changes.

The present study was undertaken to evaluate the influence of rumen-protected folic acid (RPFA) on slaughter performance, visceral organ and gastrointestinal tract coefficients, and meat quality in lambs. Sixty-six lambs from 120 Hu ewes were selected based on body weight and maternal diets and then assigned to six groups using a randomised block experimental design in a 3 × 2 factorial arrangement. The first factor was folic acid (FA) as RPFA in the maternal diet (0 mg/kg (M0F), 16 mg/kg (M16F) or 32 mg/kg (M32F) on DM basis). The second factor was FA in the lambs’ diet from weaning until slaughter (0 mg/kg (OC) or 4·0 mg/kg (OF)). The results indicated that the addition of 16 mg/kg FA to the maternal diet increased pre-slaughter weight (PSW), dressing and meat percentage, the reticulum and omasum coefficients, length of the jejunum and ileum, tail fat and perirenal fat coefficient and a* value of the meat colour. The addition of RPFA to the lambs’ diet increased PSW, dressing and meat percentage, eye muscle area, abomasum weight, weight and length of the small intestine, but reduced the coefficients of tail fat. An M × O interaction was observed for the weights of heart, lungs, rumen and total stomach, weight and coefficient of omental fat and the girth rib value. Collectively, RPFA in the maternal and lambs’ diet improved slaughter performance and meat quality by stimulating the morphological development of the gastrointestinal tract and the distribution of fat in the body.

An experiment of divergent selection for intramuscular fat was carried out at Universitat Politècnica de València. The high response of selection in intramuscular fat content, after nine generations of selection, and a multidimensional scaling analysis showed a high degree of genomic differentiation between the two divergent populations. Therefore, local genomic differences could link genomic regions, encompassing selective sweeps, to the trait used as selection criterion. In this sense, the aim of this study was to identify genomic regions related to intramuscular fat through three methods for detection of selection signatures and to generate a list of candidate genes. The methods implemented in this study were Wright’s fixation index, cross population composite likelihood ratio and cross population – extended haplotype homozygosity. Genomic data came from the 9th generation of the two populations divergently selected, 237 from Low line and 240 from High line. A high single nucleotide polymorphism (SNP) density array, Affymetrix Axiom OrcunSNP Array (around 200k SNPs), was used for genotyping samples. Several genomic regions distributed along rabbit chromosomes (OCU) were identified as signatures of selection (SNPs having a value above cut-off of 1%) within each method. In contrast, 8 genomic regions, harbouring 80 SNPs (OCU1, OCU3, OCU6, OCU7, OCU16 and OCU17), were identified by at least 2 methods and none by the 3 methods. In general, our results suggest that intramuscular fat selection influenced multiple genomic regions which can be a consequence of either only selection effect or the combined effect of selection and genetic drift. In addition, 73 genes were retrieved from the 8 selection signatures. After functional and enrichment analyses, the main genes into the selection signatures linked to energy, fatty acids, carbohydrates and lipid metabolic processes were ACER2, PLIN2, DENND4C, RPS6, RRAGA (OCU1), ST8SIA6, VIM (OCU16), RORA, GANC and PLA2G4B (OCU17). This genomic scan is the first study using rabbits from a divergent selection experiment. Our results pointed out a large polygenic component of the intramuscular fat content. Besides, promising positional candidate genes would be analysed in further studies in order to bear out their contributions to this trait and their feasible implications for rabbit breeding programmes.

The interest in biodiesel production from oil-bearing seeds rather than soybean necessitates the scientific validation of other good quality protein sources that could substitute soybean meal in animal diets, particularly, broiler chickens where soybean meal constitutes a large portion of their diet. Therefore, the present study was conducted to investigate the effect of sun-dried Azolla leaf meal (ALM) as an unconventional dietary protein source in broiler chicken diet on growth performance, meat quality, skeletal muscle cell growth and protein synthesis through regulation of ribosomal protein S6 kinase (p70S6 kinase α). A total of 120 male Ross 308 broiler chicks were randomly allocated to three dietary treatments. Each treatment had four cages (i.e. replicates) with 10 birds/cage. The control group was fed with a corn–soy-based diet, the AZ5 group was supplemented with 5% ALM and the AZ10 group was supplemented with 10% ALM for 37 days. A 5-day trial was also conducted to measure the apparent nutrient digestibility. Growth performance parameters were measured weekly. At the end of the experiment, 12 birds from each group (3/cage) were euthanized and used for samplings. Inclusion of ALM tended to improve BW gain (P = 0.06) and increased feed intake (P < 0.01). Additionally, ALM decreased the percentage of breast meat cooking loss linearly (P < 0.01). In addition, ALM at a dose of 5% increased the production of propionate in the cecum (P = 0.01). Activation of breast muscle p70S6 kinase was higher when ALM was included in a dose-dependent manner (P < 0.01). The inclusion of ALM increased breast meat redness (P < 0.01); however, the lightness was within the normal range in all groups. Findings from our study suggest that ALM could be included in a broiler chicken diet up to 5% without any major negative effect on meat quality or performance, and it regulates muscle protein synthesis through activation of mammalian target of rapamycin/6S kinase signaling.

Our research group demonstrated that vitamin A restriction affected meat quality of Angus cross and Simmental steers. Therefore, the aim of this study is to highlight the genotype variations in response to dietary vitamin A levels. Commercial Angus and Simmental steers (n = 32 per breed; initial BW = 337.2 ± 5.9 kg; ~8 months of age) were fed a low-vitamin A (LVA) (1017 IU/kg DM) backgrounding diet for 95 days to reduce hepatic vitamin A stores. During finishing, steers were randomly assigned to treatments in a 2 × 2 factorial arrangement of genotype × dietary vitamin A concentration. The LVA treatment was a finishing diet with no supplemental vitamin A (723 IU vitamin A/kg DM); the control (CON) was the LVA diet plus supplementation with 2200 IU vitamin A/kg DM. Blood samples were collected at three time points throughout the study to analyze serum retinol concentration. At the completion of finishing, steers were slaughtered at a commercial abattoir. Meat characteristics assessed were intramuscular fat concentration, color, Warner-Bratzler shear force, cook loss and pH. Camera image analysis was used for determination of marbling, 12th rib back fat and longissimus muscle area (LMA). The LVA steers had lower (P < 0.001) serum retinol concentration than CON steers. The LVA treatment resulted in greater (P = 0.03) average daily gain than the CON treatment, 1.52 and 1.44 ± 0.03 kg/day, respectively; however, there was no effect of treatment on final BW, DM intake or feed efficiency. Cooking loss and yield grade were greater and LMA was smaller in LVA steers (P < 0.05). There was an interaction between breed and treatment for marbling score (P = 0.01) and percentage of carcasses grading United States Department of Agriculture (USDA) Prime (P = 0.02). For Angus steers, LVA treatment resulted in a 16% greater marbling score than CON (683 and 570 ± 40, respectively) and 27% of LVA Angus steers graded USDA Prime compared with 0% for CON. Conversely, there was no difference in marbling score or USDA Quality Grades between LVA and CON for Simmental steers. In conclusion, feeding a LVA diet during finishing increased marbling in Angus but not in Simmental steers. Reducing the vitamin A level of finishing diets fed to cattle with a high propensity to marble, such as Angus, has the potential to increase economically important traits such as marbling and quality grade without negatively impacting gain : feed or yield grade.

The meat quality of chicken is an important factor affecting the consumer’s health. It was hypothesized that n-3 polyunsaturated fatty acid (n-3 PUFA) could be effectively deposited in chicken, by incorporating antioxidation of soybean isoflavone (SI), which led to improved quality of chicken meat for good health of human beings. Effects of partial or complete dietary substitution of lard (LA) with linseed oil (LO), with or without SI on growth performance, biochemical indicators, meat quality, fatty acid profiles, lipid-related health indicators and gene expression of breast muscle were examined in chickens. A total of 900 males were fed a corn–soybean meal diet supplemented with 4% LA, 2% LA + 2% LO and 4% LO and the latter two including 30 mg SI/kg (2% LA + 2% LO + SI and 4% LO + SI) from 29 to 66 days of age; each of the five dietary treatments included six replicates of 30 birds. Compared with the 4% LA diet, dietary 4% LO significantly increased the feed efficiency and had no negative effect on objective indices related to meat quality; LO significantly decreased plasma triglycerides and total cholesterol (TCH); abdominal fat percentage was significantly decreased in birds fed the 4% LO and 4% LO + SI diets. Chickens with LO diets resulted in higher contents of α-linolenic acid (C18:3n-3), EPA (C20:5n-3) and total n-3 PUFA, together with a lower content of palmitic acid (C16:0), lignoceric acid (C24:0), saturated fatty acids and n-6:n-3 ratio in breast muscle compared to 4% LA diet (P < 0.05); they also significantly decreased atherogenic index, thrombogenic index and increased the hypocholesterolemic to hypercholesterolemic ratio. Adding SI to the LO diets enhanced the contents of EPA and DHA (C22:6n-3), plasma total superoxide dismutase, reduced glutathione (GSH)/oxidized glutathione and muscle GSH content, while decreased plasma total triglyceride and TCH and malondialdehyde content in plasma and breast muscle compared to its absence (P < 0.05). Expression in breast muscle of fatty acid desaturase 1 (FADS1), FADS2, elongase 2 (ELOVL2) and ELOVL5 genes were significantly higher with the LO diets including SI than with the 4% LA diet. Significant interactions existed between LO level and inclusion of SI on EPA and TCH contents. These findings indicate that diet supplemented with LO combined with SI is an effective alternative when optimizing the nutritional value of chicken meat for human consumers.

Recently, Echinacea purpurea and its extracts have gained much interest due to their improvement on meat quality, but little information is available on the application of the purified Echinacea purpurea polysaccharide (4-O-methyl-glucuronoarabinoxylan, 4OMG). Thus, this trial aimed at assessing the effects of dietary supplementation of 4OMG on growth performance, thigh meat quality and small intestine development of broilers. A total of 240 1-day-old female broiler chicks were randomly distributed to four groups with three replicates of 20 within each group. Each group received either 0, 15, 20 or 25 g 4OMG/kg DM of diet. During the entire experiment, broilers had ad libitum access to water and feed, and the feed intake was recorded daily. All broilers were weighed before and end of the experiment. For each group, three pens with a total of 20 broilers were randomly selected to slaughter after 30 days. Increasing dietary supplementation of 4OMG linearly increased final live weight and daily body weight gain (P = 0.013) of broilers, Gain-to-Feed ratio (P < 0.001), muscle pH (P = 0.024) and redness (P = 0.001), but decreased drip loss (P = 0.033), shear force value (P = 0.004) and hardness (P = 0.022) of the thigh meat. Broilers fed diet with higher 4OMG had greater weight index, villus height and ratio of villus height to crypt depth in both duodenum and jejunum. These results indicated that increasing dietary supplementation of 4OMG was beneficial for growth performance, meat quality and development of the small intestine of broilers.

The current study evaluated the effects of dietary roughage:concentrate (R:C) ratios and water supply on the carcass characteristics and yield of lambs. Forty Santa Inês crossbred lambs with an average body weight (BW) of 19 ± 2.8 kg were evaluated in a completely randomized design with a 2 × 2 factorial arrangement consisting of two proportions of roughage and concentrate (30:70 and 70:30) and two levels of water supply (ad libitum and restricted to 0.5). The animals were slaughtered at an average weight of 28 ± 31 kg. Centesimal composition, colour parameters (L*, a* and b*), shear force, cooking losses and pH were determined on the Longissimus lumborum muscle. There was no interaction effect between the R:C ratio and water supply on the evaluated variables. Total BW gain, average daily gain and final BW were affected by water restriction and R:C ratio. Water restriction reduced total BW gain, average daily gain and final BW. No effect of water restriction was detected on slaughter weight, centesimal composition, colour variations, shear force, pH, weight or yield of carcass. No effect of water restriction and diets was observed on the cuts, except for neck weight. Carcass weight and yield were affected by the R:C ratios. Restricting the water supply to 0.5 does not affect the carcass weight or yield of Santa Inês crossbred lambs or their meat quality characteristics (centesimal composition, colour, shear force and pH measurements). A higher proportion of concentrate in the diet results in heavier hot and cold carcass weights.

Incidences of myopathies such as white striping (WS), woody breast (WB) and spaghetti meat (SP) in breast meat from young broilers have been observed globally over the past decade. Some industry reports suggest up to 20% WB occurrence in fast growing heavy broilers (~4.0 kg) with an estimated cost of more than US$500 million/year to the US industry alone, but may actually be far higher. The proportions and severity of the anomaly appear to be flock-dependent and are related to factors such as genetics, nutrition (e.g. protein level during the fast-growing phase), growth rate, activity of the birds at young age, sudden bursts of activity, number of embryonic stem cells and litter management. These three myopathies can appear together or individually, but it appears that they are all related. When meat is processed, these myopathies represent quality issues (firmer meat and/or lower water binding, aesthetics) but do not present a food safety issue. The poultry industry is now focusing on ways to reduce or eliminate the occurrence of these myopathies. Recently some improvements have been made as more is learned about the interactions between environmental and management (e.g., nutrition) factors, and some producers are already implementing new procedures. Breeding programmes are starting to show some promise and are expected to help reduce WB (estimated at 10% of birds per year) and deliver more solutions in the future.

Slow-growing, male chickens raised with outdoor access have been found to be a nutritious protein source with 24.83% protein in breast muscle. They have an acceptable carcass quality with at least 20% less abdominal fat, 3% more breast yield, and 3% more thigh yield than the birds raised in confinement. Similarly, slow-growing male chickens grown with outdoor access have a good bone quality with femur weight, length and diameter (16.5 g, 96.7 mm, and 8.61 mm, respectively). Considering fatty acid profile as a meat quality trait, breast muscles of slow-growing birds grown with outdoor access compared to those without such access have significantly higher polyunsaturated fatty acids level (3.85 vs. 3.36%), lower n6:n3 PUFA ratio (7.8 vs. 9.22) and lower saturated fatty acids content (26.29 vs. 28.73%). Raising slow-growing male chickens in production systems with outdoor access has been confirmed to be beneficial for the animals, the producers, the consumers and the environment.

Guinea fowl production is increasing in developing countries and has a crucial role in the fight against poverty. However, the feed cost is very high, especially the soya bean meal cost, and farmers cannot afford to buy commercial feed. Consequently, animals do not receive feed adapted to their nutritional needs and they exhibit poor performance. The aim of this paper is to partially substitute soya bean meal by local by-products, discarded, in abundant supply and not used in human nutrition. French Galor guinea fowl (Numida meleagris) and local African guinea fowl (150 birds per breed) were reared for 16 weeks and fed the same starter diet for the initial 4 weeks. From 4 weeks of age, experimental birds from each breed were randomly assigned to three grower isoproteic and isolipidic dietary treatments, each containing five replications (floor pens); each replication included 10 birds of the same breed. The guinea fowl of each breed were fed either control grower diet using soya bean meal as the protein supplement GS, or trial grower diet GN (soya bean meal supplement partially substituted by 15% cashew nut (Anacardium occidentale) meal) or trial grower diet GH (soya bean meal supplement partially substituted by 15% hevea seed (Hevea brasiliensis) meal). The results indicated that hevea seed meal contained a high content of n-3 polyunsaturated fatty acids (PUFAs) (21.2% of total fatty acids (FAs)). The use of hevea seed meal in guinea fowl grower diet was found to exert no adverse effect on growth performance and carcass yield. However, the use of cashew nut meal led to negative effects on performance like daily weight gain and feed conversion ratio. Therefore, cashew nut meal cannot be considered as a suitable partial substitute for soya bean meal in diets. The use of hevea seed meal led to a very low abdominal fat proportion and low blood triglyceride and cholesterol content. Additionally, inclusion of dietary hevea seed meal resulted in guinea fowl meat enriched in PUFAs, especially n-3 FAs, thereby significantly improving the nutritional value.