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A total of 576 rabbits were housed in 18 open-top elevated pens (32 rabbits per pen) during the fattening period (54–71 d of age) and fed a standard diet or a diet enriched in purified wood lignocellulose and fat formulated to guarantee rabbit optimal digestive health and convenient feed conversion ratio. The impacts on gut microbiota (both hard faeces and caecal content) and caecal fermentation, diet digestibility and rabbit performance were examined. The microbial diversity and the bacterial community structure of hard faeces barely differed from that of caecal content (p >.05). No differences in alpha and beta diversity of microbiota were detected between rabbits fed the different diets. Twelve genera, mostly belonging to the family of Lachnospiraceae, increased (p <.05) in rabbits fed the diet added with the purified lignocellulose and fat. The increase of insoluble fibre by purified wood lignocellulose reduced the digestibility of fibre fractions (NDF digestibility 19.2% vs. 26.8%; p <.001) while increasing protein (73.5% vs. 71.6%; p <.01) and ether extract digestibility. Growth performance was not affected by the dietary treatment (average daily weight gain: 40.9 g/d; feed conversion ratio: 4.04). Total losses (dead + underweight animals) averaged at 4.17% without significant differences between the dietary treatments. In conclusion, the addition of purified wood lignocellulose in fat-added diets did not affect rabbit performance and overall farm efficiency was maintained. Some changes in the caecal fermentation profile may indicate a change in microbial pathways rather than composition, where no significant effects on the gut microbiota were observed. HIGHLIGHTS: Low levels of pure lignocellulose added to diets along with fat do not compromise the overall farm efficiency. No major effects on gut microbiota were observed. A few changes of the caecal fermentation profile were recorded. [ABSTRACT FROM AUTHOR]

Simple Summary: Poultry farming is set to expand in the future, and consumers are requiring more sustainable and ethical products. Free-range farming systems produce high-quality meat and also present added value in terms of welfare, sustainability, small-scale farmers' development, and ethical farming. Local chicken breeds should be used in organic and free-range farming, but they have long growth periods. As found in the present study, crossbreeding could improve growth results, thus safeguarding local chicken biodiversity. Local chicken breeds play a vital role in promoting sustainability by preserving genetic diversity, enhancing resilience, and supporting local economies. These breeds are adapted to local climates and conditions, requiring fewer external resources and inputs for their maintenance. By conserving and utilizing local chicken breeds, sustainable farming practices can be incentivized, maintaining ecosystem balance and ensuring food security for future generations. The present study aimed at evaluating the growth performance and slaughter traits of two local Italian chicken breeds (Bionda Piemontese and Robusta Maculata) and their crosses with a medium-growth genotype (Sasso chicken®) reared in conventional and free-range farming systems. The conventional system used a high-energy high-protein diet in a closed barn with controlled temperature, humidity, and lighting, and a stocking density of 33 kg/m2. The free-range system used a low-input diet (low-energy low-protein diet composed of local and GMO-free feed ingredients), uncontrolled environmental conditions, and a stocking density of 21 kg/m2 in a barn with free access to an outdoor area. The birds were slaughtered at 84 days of age in both systems. The crossbred chickens showed the best results for growth performance in both farming systems compared to local breeds. Within genotype, the final live weight of chickens was similar in the two farming systems. In conclusion, slow-growth crossbreeds should be used in alternative farming systems, demonstrating better performance than pure local breeds. [ABSTRACT FROM AUTHOR]

Myopathies of the breast muscle in broiler chickens are a great concern of modern poultry production because of the economic losses associated with the waste of unfit meat, the effects on meat nutritional quality for food and on meat technological quality for processing, and last, but not less important, the effects on animal welfare and health. Largely spread in fast-growing genotypes, these muscle defects have a low hereditability for which genetic selection for their control seems to be a weak strategy or, at least, a weak long-term strategy. On the other hand, several investigations have been performed on the physiological mechanisms triggering the onset and the evolution of myopathies, and different non-genetic strategies have been proposed to control their in vivo occurrence. Thus, the present paper aimed to analyse the scientific literature investigating the effects of feeding and nutritional strategies on the occurrence of myopathies to find out the most tested strategies, the most promising ones and, in perspective, strengths and weakness of the same strategies. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the carcass traits and meat quality of growing rabbits reared in four types of commercially available housing systems (i.e. bicellular cages, dual-purpose cages, enriched cages and elevated pens) across three production cycles covering different seasons (i.e. autumn, winter and summer) under field conditions. The rabbits originated from 12 commercial farms (three farms per housing system) located in the Northeast of Italy and were slaughtered in five commercial slaughterhouses at a slaughter age from 71 to 90 d. Twenty carcasses per farm and cycle were randomly selected at the slaughterhouse and carcass and meat quality traits were evaluated 24 h post-mortem. The heaviest carcass weights were found in rabbits reared in enriched cages, followed by those in parks, while the lightest carcasses were found in rabbits from bicellular cages. Carcass fat and longissimus lumborum proportions were higher and hind legs proportion lower in carcasses of rabbits kept in enriched cages compared to those from the other systems. Based on significant differences for meat quality traits (i.e. pH, L*, thawing losses and shear force) among housing systems, ante-mortem stress was likely lower in rabbits from enriched cages and parks than in those from bicellular and dual-purpose cages. Nevertheless, these differences were not translated into noticeable changes in meat quality because of the small variations among housing systems. Overall, the observed differences could not be strictly and exclusively related to the enclosure in which the animals were housed, but also to other production and ante-mortem factors. The rearing season significantly affected slaughter traits, with lower slaughter and carcass weights in summer compared to winter and autumn. Despite the limit in the sample size of investigated farms, this study highlighted that under field conditions the final product quality of rabbits is not clearly distinguishable based on the housing system per se. [ABSTRACT FROM AUTHOR]

Poultry meat is consumed worldwide and its production is expected to increase in the upcoming years. Genetic selection in poultry focused on growth rate, feed conversion, and breast yield, resulting in the occurrence of white striping and wooden breast abnormalities and, most recently, spaghetti meat. These myopathies affect the quality traits of raw meat, including pH, color, water holding capacity, and cooking loss, which limit its further processing and decrease consumer acceptance. Additionally, the effects of myopathies on the chemical composition, i.e., reduced protein and essential amino acid content and increased fat contents, impair to some extent the nutritional value of the meat. [ABSTRACT FROM AUTHOR]

Simple Summary: Precision livestock farming (PLF) techniques facilitate automated, continuous, and real-time monitoring of animal behaviour and physiological responses. They also have the potential to improve animal welfare by providing a continuous picture of welfare states, thus enabling fast actions that benefit the flock. Using a PLF technique based on images, the present study aimed to test a machine learning tool for measuring the number of hens on the ground and identifying the number of dust-bathing hens in an experimental aviary—a complex environment—by comparing the performance of two machine learning (YOLO, You Only Look Once) models. The results of the study revealed that the two models had a similar performance; however, while PLF was successful in evaluating the distribution of hens on the floor and predicting undesired events, such as smothering due to overcrowding, it failed to identify the occurrence of comfort behaviours, such as dust bathing, which are part of the evaluation of hen welfare. Image analysis using machine learning (ML) algorithms could provide a measure of animal welfare by measuring comfort behaviours and undesired behaviours. Using a PLF technique based on images, the present study aimed to test a machine learning tool for measuring the number of hens on the ground and identifying the number of dust-bathing hens in an experimental aviary. In addition, two YOLO (You Only Look Once) models were compared. YOLOv4-tiny needed about 4.26 h to train for 6000 epochs, compared to about 23.2 h for the full models of YOLOv4. In validation, the performance of the two models in terms of precision, recall, harmonic mean of precision and recall, and mean average precision (mAP) did not differ, while the value of frame per second was lower in YOLOv4 compared to the tiny version (31.35 vs. 208.5). The mAP stands at about 94% for the classification of hens on the floor, while the classification of dust-bathing hens was poor (28.2% in the YOLOv4-tiny compared to 31.6% in YOLOv4). In conclusion, ML successfully identified laying hens on the floor, whereas other PLF tools must be tested for the classification of dust-bathing hens. [ABSTRACT FROM AUTHOR]

To evaluate the effects of the dietary supplementation with a grape seeds extract (GSE) on growth performance, gut morphology and immune response, and meat quality, 800 chickens (8 pens/group) were fed a control diet or the same diet added with 0.1%, 0.2%, or 0.4% GSE from hatching to 42 d of age. Growth performance did not differ among dietary treatments: final live weight averaged at 3,179 g, which corresponded to a daily growth rate of 76.1 g/d; feed intake averaged 113 g/d, for a feed conversion ratio at 1.49. On average of samplings at 14 d and 28 d of age, the density of CD45+ cells in the jejunal mucosa was higher (2,497 vs. 1,931 cells/10,000 μm2; p <.001) in chickens fed diet 0.2% GSE compared to chickens fed the other diets; jejunum villi height tended to be lower in chickens fed diet 0.2% GSE compared to those fed the other diets (965 μm vs. 1,054 μm; p =.07). Slaughter results and carcase traits, occurrence of myopathies at breast and meat quality after 24 h or 11 d of refrigerated storage were not affected by GSE inclusion or level. Under the conditions of the present study, no relevant effect of the dietary inclusion of GSE was observed on performance and health, but a pro-inflammatory immune response at the level of jejunum, based on which a positive response of chickens fed GSE can be expected under challenging conditions. Dietary supplementation with grape seed extract from 0.1% to 0.2% and 0.4% were tested in broiler chickens. Growth performance, meat oxidation and myopathy occurrence were not affected. A pro-inflammatory immune response at the level of jejunum was recorded with 0.2% inclusion level. [ABSTRACT FROM AUTHOR]

Simple Summary: The nutritional composition of the diets for growing rabbits should be well-balanced, both to meet the requirements of the high-producing hybrids currently used and to avoid nutrient losses. The improvement of the feed conversion ratio represents a key point in increasing rabbit farmers' profitability because of the high feeding costs. This study evaluated the growth performance, digestive efficiency and meat quality of growing rabbits belonging to the most diffused commercial crossbred rabbit breeds, Grimaud and Hyla, feeding them diets with different energy and protein levels. The two genotypes showed similar growth performance, but Grimaud rabbits achieved higher slaughter yield than Hyla rabbits. The administration of high-energy diets improved feed conversion and increased nutrient digestibility. Conversely, low dietary protein contents reduced nitrogen excretion without negative effects on growth, feed efficiency and carcass traits of fast-growing rabbits. The present study evaluated the effect of digestible energy (DE) and crude protein (CP) levels on growth, digestive efficiency, slaughter yield and meat quality in growing rabbits of two genotypes (Grimaud, G vs. Hyla, H). A total of 384 crossbred rabbits (192 G and 192 H), half males and half females, were divided into eight experimental groups according to a bi-factorial arrangement (2 genotypes × 4 diets; 48 animals/group) and reared in individual cages. From 33 to 64 days of age, rabbits were fed four diets obtained by combining two DE levels (high, HE—10.9 MJ/kg vs. low, LE—9.2 MJ/kg, on average) and two CP levels (high, HP—159 g/kg vs. low, LP—144 g/kg, on average). Then, all rabbits received the same fattening diet (10.7 MJ DE/kg; 156 g CP/kg) until slaughtering (77 days of age). Growth performance did not differ between genotypes for the entire trial (on average final live weight 3010 g; daily weight gain 50.5 g/d), but H rabbits showed a faster growth during the post-weaning period (p ≤ 0.01) compared to G rabbits, while exhibiting lower slaughter yield and lower carcass fatness (p ≤ 0.01). As DE level increased, feed intake decreased and feed conversion improved (p < 0.001), while caecal volatile fatty acid concentration increased and caecal pH and N-ammonia decreased (p ≤ 0.01). The reduction in the CP level did not affect performance and carcass traits. No significant interaction was detected between genotype and diet. In conclusion, G rabbits may have an advantage over H rabbits because of the higher slaughter yield. As for the nutritional characteristics of diets for high-producing crossbred rabbits, high energy levels are confirmed to enhance feed efficiency, whereas dietary CP can be reduced to 144 g/kg without negative effects on performance and carcass traits. [ABSTRACT FROM AUTHOR]

Fast-growing broiler chickens are subjected to breast myopathies such as white striping (WS), wooden breast (WB), and spaghetti meat (SM). Available studies about risk factors for myopathy occurrence often used flock data whereas a few reports evaluated chicken individual data. Thus, the present study aimed to elucidate the effect of growth and slaughter traits, besides sex and genotype on myopathy occurrence. Data were obtained from eight experimental trials, which used a total of 6,036 broiler chickens. Sex, genotype, daily weight gain, slaughter weight, and breast yield were evaluated as potential risk factors by logistic regression analyses. Then, the effects of myopathy and sex were evaluated on meat rheological traits (pH, colour, cooking losses and shear force). Based on a logistic regression, WS occurrence was associated with genotype, breast weight, and breast yield. Compared with chickens with intermediate breast weight and breast yield, higher odds of having WS were found in chickens with high breast weight (OR: 1.49) and yield (OR: 1.27), whereas lower odds were found in those with low breast weight (OR: 0.57) and yield (OR: 0.82). As for WB and SM, females had lower odds of having WB (OR: 0.55) and higher odds of showing SM (OR: 15.4) compared to males. In males, higher odds of having WBwere found in chickens with a high daily weight gain (OR: 1.75) compared to those with an intermediate daily weight gain. In females, higher odds of having SM were associated to a high slaughter weight (OR: 2.10) while lower odds to a low slaughter weight (OR: 0.87). As for meat quality, only WB meat was clearly different for some technological and sensorial properties, which can play a major role also in meat processing. In conclusion, our analysis identified breast development as a potential risk factor for WS, while a high growth was the risk factor for WB and SM. A different probability of having WB or SM in females and male was found. [ABSTRACT FROM AUTHOR]

Simple Summary: Alternative cage-free housing systems for growing rabbits, such as parks/elevated pens, are currently being developed in Mediterranean countries. In these parks, the inability to express gnawing behavior and fear are the top behavioral-welfare-associated consequences. Gnawing inability promotes abnormal stereotypical and aggressive behaviors. Fear can be reduced by avoiding aggression. Thus, the present study aims to evaluate the effect of gnawing compressed hay blocks and sex-group composition (only females, only males, mixed sex) on the productive results, behavior, and reactivity of growing rabbits in a park system. None of the animals showed injuries due to aggression at the end of the trial. The provision of gnawing blocks affected rabbit behavior negligibly but improved their reactivity towards a new environment or a new object; thus, the inclusion of gnawing blocks should be recommended for animal welfare. Changes in sex-group composition were not relevant in terms of either quantity or quality of performance and conspecific interactions. To improve animal welfare in collective park housing systems, this study assessed the effects of the provision of gnawing hay blocks and the group composition (F: females, M: males, FM: mixed sex) on performance, behavior, and reactivity of 288 growing rabbits reared in 18 parks (16 rabbits/park) from 31 to 73 days of age. The presence of gnawing blocks inside the feeding area of the parks scarcely affected performance and budget time, but decreased the time spent in the resting area compared to parks without blocks (p < 0.001); it increased the time spent moving during the open field test (p < 0.05) and the rate of rabbits that approached the object in the novel-object test (p < 0.05). As for sex-group composition, the feed conversion ratio was lower in parks F and FM than in park M (p < 0.05). During the open-field test, FM rabbits spent more time moving (p < 0.05), whereas M rabbits displayed self-grooming for a longer time (p < 0.01). Results related to production, behavior, and reactivity indicate the provision of gnawing blocks for welfare improvement, but do not support the change from current mixed-sex to single-sex rearing. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of globin and spray‐dried porcine plasma (SDPP) on growth performance, digestibility, nitrogen retention, energy retention efficiency (ERE) and intestinal morphology of broiler chickens. A total of 336‐day‐old male broiler chickens were reared from 1 to 40 days of age and fed 3 diets (8 replicates/diet, 14 birds/replicate) during 3 feeding phases: starter (1–12 days), grower (12–25 days) and finisher (25–40 days). Isonitrogenous diets were formulated by replacing gluten protein isolate contained in the control diet (C diet) with 2% (starter) or 1% (grower and finisher) spray‐dried porcine plasma in the plasma diet (SDPP diet). The globin diet (G diet) was obtained by adding globin on the top of C diet at a dose of 0.08% for the whole rearing period. Total tract apparent digestibility (aD), nitrogen retention and ERE were assessed during the three growing phases. At 12 and 40 days of age, one bird per pen was slaughtered to sample gut, liver, spleen and bursa of Fabricius for histomorphological investigations. The SDPP diet increased body weights of chickens at 12 (+60 g; p <.001), 25 (+101 g; p <.001) and 40 days (+130 g; p =.018) of age compared to C and G diets. Also SDPP improved crude protein aD (+9.7%) and ERE (+12.3%) during the starter phase (p <.001). Dietary globin and SDPP inclusion did not affect either the gut morphology or the histopathological findings in birds at 12 and 40 days of age, despite a numerical (+6.90% and +7.40% respectively) villus height improvement in the SDPP group. Overall, these results confirm that dietary supplementation with SDPP and, to a lesser extent, with globin can improve growth performance and dietary protein and energy utilization in broiler chickens without effect on gut functionality. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of globin and spray-dried porcine plasma (SDPP) on growth performance, digestibility, nitrogen retention, energy retention efficiency (ERE) and intestinal morphology of broiler chickens. A total of 336-day-old male broiler chickens were reared from 1 to 40 days of age and fed 3 diets (8 replicates/diet, 14 birds/replicate) during 3 feeding phases: starter (1-12 days), grower (12-25 days) and finisher (25-40 days). Isonitrogenous diets were formulated by replacing gluten protein isolate contained in the control diet (C diet) with 2% (starter) or 1% (grower and finisher) spray-dried porcine plasma in the plasma diet (SDPP diet). The globin diet (G diet) was obtained by adding globin on the top of C diet at a dose of 0.08% for the whole rearing period. Total tract apparent digestibility (aD), nitrogen retention and ERE were assessed during the three growing phases. At 12 and 40 days of age, one bird per pen was slaughtered to sample gut, liver, spleen and bursa of Fabricius for histomorphological investigations. The SDPP diet increased body weights of chickens at 12 (+60 g; p < .001), 25 (+101 g; p < .001) and 40 days (+130 g; p = .018) of age compared to C and G diets. Also SDPP improved crude protein aD (+9.7%) and ERE (+12.3%) during the starter phase (p < .001). Dietary globin and SDPP inclusion did not affect either the gut morphology or the histopathological findings in birds at 12 and 40 days of age, despite a numerical (+6.90% and +7.40% respectively) villus height improvement in the SDPP group. Overall, these results confirm that dietary supplementation with SDPP and, to a lesser extent, with globin can improve growth performance and dietary protein and energy utilization in broiler chickens without effect on gut functionality. [ABSTRACT FROM AUTHOR]

In this study, we compared three popular textural tests: the compression, Meullenet–Owens razor blade (MORS), and Allo–Kramer (AK) tests, which are used to detect the wooden breast (WB) and spaghetti meat (SM) myopathies. A total of 209 fillets (71 WB, 71 SM, 67 normal) were selected from three different flocks at a large commercial plant. Thawed fillets were subjected to 20% compression tests before and after cooking, and cooked samples were subjected to the MORS and AK tests. The compression test on raw samples showed that normal and SM fillets had lower force (5.61 and 4.69 vs. 9.52 N), work (25 and 22 vs. 45 N mm), and Young's modulus (2.71 and 2.11 vs. 4.29 N/s, p <.001) values than those of WB. The results of the compression test were confirmed by the cooked fillet results. The MORS test showed that SM had lower shear force (12.8 vs. 14.7 N) and work (249 vs. 288 N mm) values than those of the normal fillets, while WB showed intermediate values. The AK test results showed that SM had lower shear force (10.5 vs. 14.5 N) and Young's modulus (31.0 vs. 46.0 N/s; p ≤.01) values than those of WB fillets, whereas normal fillets had intermediate values. The compression test can be used to identify WB in both raw and cooked meat. The MORS test could distinguish cooked SM fillets from normal fillets, whereas the AK test differentiated SM from WB. This study compared the compression, Meullenet–Owens razor blade, and Allo–Kramer tests for detecting wooden breast (WB) and spaghetti meat (SM). The compression test identified WB in both raw and cooked fillets. Meullenet–Owens razor blade test distinguished SM from normal fillets. Allo–Kramer test accurately distinguished SM from WB fillets. [ABSTRACT FROM AUTHOR]

Objectives Near-infrared (NIR) spectroscopy is a rapid technique able to assess meat quality even if its capability to determine the shelf life of chicken fresh cuts is still debated, especially for portable devices. The aim of the study was to compare bench-top and portable NIR instruments in discriminating between four chicken breast refrigeration times (RT), coupled with multivariate classifier models. Materials and Methods Ninety-six samples were analysed by both NIR tools at 2, 6, 10 and 14 days post mortem. NIR data were subsequently submitted to partial least squares discriminant analysis (PLS-DA) and canonical discriminant analysis (CDA). The latter was preceded by double feature selection based on Boruta and Stepwise procedures. Results PLS-DA sorted moderate separation of RT theses, while shelf life assessment was more accurate on application of Stepwise-CDA. Bench-top tool had better performance than portable one, probably because it captured more informative spectral data as shown by the variable importance in projection (VIP) and restricted pool of Stepwise-CDA predictive scores (SPS). Conclusions NIR tools coupled with a multivariate model provide deep insight into the physicochemical processes occurring during storage. Spectroscopy showed reliable effectiveness to recognise a 7-day shelf life threshold of breasts, suitable for routine at-line application for screening of meat quality. [ABSTRACT FROM AUTHOR]

The present study aimed to evaluate how dietary supplementation with a microencapsulated sodium butyrate (500 mg/kg; 30% Na-butyrate) in 768 male and female broiler chickens affected growth performance, jejunum gut morphology and caecal microbiome at different ages (11, 24, and 35 d), slaughter results, meat quality, and myopathy (white striping, wooden breast, and spaghetti meat) occurrence. No health problem was recorded (mortality < 1%) and Na-butyrate supplementation did not affect performance throughout the trial, nor did it affect gut morphology or microbiota composition and abundance at different ages. Additionally, dietary treatment did not affect slaughter results, meat quality, or myopathy rate, whereas the rate of females affected by spaghetti meat tended to be higher in those fed the control compared with the Na-butyrate diet (33.3% versus 16.7%; p =.06). Moreover, males showed a higher wooden breast (21.9% versus 7.3%; p ≤.01) and a lower spaghetti meat (3.1% versus 25.0%; p ≤.001) rate compared with females. Finally, the richness index (i.e. the number of different species represented in an ecological community, landscape, or region) in the caecum increased (p ≤.001) with increasing chicken age, and the community composition was also affected (adonis p ≤.001). In conclusions, under the good health condition of the present trial, the tested Na-butyrate had no effect on performance and gut response at different ages of broiler chickens. Moreover, the occurrence of spaghetti meat and wooden breast differed between males and females. Under optimal health conditions, Na-butyrate supplementation did not affect performance or gut response at different ages of broiler chickens. Males showed a significantly higher occurrence of wooden breasts, whereas females had higher rates of spaghetti meat. In females, the Na-butyrate supplementation tended to reduce the occurrence of spaghetti meat. [ABSTRACT FROM AUTHOR]