Lameness In Broilers Research Articles

422 The use of 3D kinematics for improved gait assessment in broilers

Abstract Genetic selection for high growth rates in broiler chickens has resulted in larger broilers and changes in broiler gait. Traditionally, broiler gait is assessed using visual observation which is subjective and labor intensive. In contrast, newer technologies are available which can be adapted to objectively score changes in broiler gait, thereby, increasing the validity and reliability of gait scoring with less labor required. The objective of this study was to compare the use of 3D kinematics versus visual scoring to assess broiler gait. Second, to determine how strain and age affect 3D kinematic gait metrics in broilers. Four strains of broiler chickens were used; two heritage strains: 1957 (H57; n = 52) and 1977 (H77; n = 51); and two commercially available strains: Cobb (n = 50) and Ross (n = 53). All broilers were weighed weekly throughout the study. Kinematic markers were placed along the spine and bony landmarks of each leg. Commercial strains had kinematic recordings and body weights (BW) recorded every week for 4 wk while Heritage strains had measurements recorded every week for 6 wk. Visual gait scoring was completed using a 5-point scale each week by two trained observers. Data were analyzed using the correlation procedure in SAS to determine the relationship between visual gait score and kinematic metrics as well as the GLIMMIX procedure to determine the effects of strain, age, and strain x age on all gait parameters. There was a weak positive correlation (r < 0.2) between visual gait score and all kinematic metrics. Cobb were the heaviest strain (1,292.6 ± 14.71 g P < 0.001) while H57 broilers were the lightest (326.4 ± 9.99 g P < 0.001). Each week, the BW of all strains increased significantly. Total Stride Time differed significantly by strain (P < 0.001; Cobb: 26.3 ± 0.47 cs, Ross: 23.1 ± 0.39 cs, H77: 23.7 ± 0.28 cs, H57: 21.5 ± 0.26 cs) and Age (P < 0.01; Commercial: wk 3: 21.8 ± 0.54 cs, wk 6: 28.1 ± 0.68 cs and Heritage: wk 3: 19.7 ± 0.42 cs, wk 8: 25.4 ± 0.52 cs). Total stride length (SL) also significantly differed by strain. Cobb had the longest SL of the two commercial strains (P < 0.001; 88.6 ± 1.94 mm) while H77 had the longest stride of the heritage strains (97.9 ± 1.51 mm). Total SL also increased with age resulting in longer stride times. Heavier birds, such as Cobb, had longer stride Times and SL compared with lighter birds such as the H57 strain. In conclusion, visual gait score and kinematic metrics were not found to be measuring the same things. However, kinematics can be a used as an informative and objective tool for assessing gait metrics associated with broiler lameness such as changes in stride length and stride time.

Identifying Dietary Timing of Organic Trace Minerals to Reduce the Incidence of Osteomyelitis Lameness in Broiler Chickens Using the Aerosol Transmission Model.

Our prior research demonstrated a 20% to 25% reduction in bacterial chondronecrosis with osteomyelitis (BCO) lameness in broilers with organic Zn, Mn, and Cu (Availa® ZMC) supplementation. Expanding on this, we investigated the optimal timing for Availa® ZMC feeding to mitigate BCO lameness and reduce feed additive costs in the poultry industry. In this study, we compared the application of 0.15% Availa® ZMC for 56 days, the first 28 days, and the last 28 days. The experimental design was a randomized block design involving 1560 one-day-old chicks distributed across two wire-floor pens as BCO source infection and four treatment groups with six replicates. The source of BCO infection exhibited a cumulative lameness incidence of 83%, whereas the negative control group showed a 77% cumulative incidence of lameness (p = 0.125). Administering 0.15% of Availa® ZMC during the initial 28 d resulted in a 41.3% reduction in BCO incidence, significantly different from the supplementation during the last 28 d (p < 0.05). However, this reduction did not differ substantially (p > 0.05) from the 56d application period. Hence, administering 0.15% Availa® ZMC during the first four weeks emerges as the optimal timing protocol, providing a defense against lameness comparable to the continuous supplementation throughout the complete production duration. Implementing this feeding approach reduces the cost of feed additive, promotes the health of skeletal bones, and effectively protects against BCO lameness in broilers, offering a valuable consideration for producers seeking optimal outcomes in the poultry industry.

Early 1,25-dihydroxyvitamin D3-glycosides supplementation: an efficient feeding strategy against bacterial chondronecrosis with osteomyelitis lameness in broilers assessed by using an aerosol transmission model

Early 1,25-dihydroxyvitamin D3-glycosides supplementation: an efficient feeding strategy against bacterial chondronecrosis with osteomyelitis lameness in broilers assessed by using an aerosol transmission model

Assessing the impact of Spirulina platensis and organic trace minerals on the incidence of bacterial chondronecrosis with osteomyelitis lameness in broilers using an aerosol transmission model

Assessing the impact of Spirulina platensis and organic trace minerals on the incidence of bacterial chondronecrosis with osteomyelitis lameness in broilers using an aerosol transmission model

Deoxynivalenol and fumonisin predispose broilers to bacterial chondronecrosis with osteomyelitis lameness

Bacterial chondronecrosis with osteomyelitis (BCO) lameness is the most critical animal health and welfare issue facing the broiler industry worldwide. It is estimated that 1 to 2% of bird condemnation at marketing age is caused by BCO lameness, resulting in tens of millions of dollars in annual losses. Fast-growing broilers are prone to mechanical stress that triggers bacterial translocation across epithelial barriers into the bloodstream, followed by bacterial colonization in the growth plate of long bones, and eventually, bone necrosis and lameness. Mycotoxins (MTX) are secondary metabolites produced naturally by microfungi, of which deoxynivalenol (DON), fumonisin (FUM), and zearalenone are the most prevalent in corn and soybean-meal-based diets. The presence of these mycotoxins in feed has been proven to reduce the barrier strength of the intestinal tracts and trigger immunosuppressive effects. In this study, we investigated the effects of the DON and FUM-contaminated feeds on the incidence of BCO lameness in broilers reared in both wire- and litter-floors. 720 one-day-old broiler chicks were assigned to the 2 × 2 factorial design: 2 MTX diets containing DON and FUM on wire flooring (MTX-W) and litter flooring (MTX-L), and 2 diets without MTX contamination on control wire flooring (CW) and control litter flooring (CL). Throughout the trial, the cumulative incidence of lameness per treatment was assessed by necropsying the lame birds. Birds in the MTX-W group had a higher incidence of lameness compared to those in CW (73.3% vs. 62.0%) (P < 0.05), and birds in the MTX-L group had a higher incidence of lameness compared to birds in CL (54.0% vs. 34.0%) (P < 0.05). MTX elicited net increases in BCO to a greater degree on litter (+20%) than on wire flooring (+12%). The increased incidence of BCO lameness in the MTX-W coincided with increased intestinal permeability supporting a correlation between intestinal barrier integrity and BCO lameness. To conclude, DON and FUM are predisposing factors for increasing BCO. However, no significant interaction exists between the diet and floor types in inducing lameness in broilers.

Automated pose estimation reveals walking characteristics associated with lameness in broilers

Walking ability of broilers can be improved by selective breeding, but large-scale phenotypic records are required. Currently, gait of individual broilers is scored by trained experts, however, precision phenotyping tools could offer a more objective and high-throughput alternative. We studied whether specific walking characteristics determined through pose estimation are linked to gait in broilers. We filmed male broilers from behind, walking through a 3 m×0.4 m (length×width) corridor one by one, at 3 time points during their lifetime (at 14, 21, and 33 d of age). We used a deep learning model, developed in DeepLabCut, to detect and track 8 keypoints (head, neck, left and right knees, hocks, and feet) of broilers in the recorded videos. Using the keypoints of the legs, 6 pose features were quantified during the double support phase of walking, and 1 pose feature was quantified during steps, at maximum leg lift. Gait was scored on a scale from 0 to 5 by 4 experts, using the videos recorded on d 33, and the broilers were further classified as having either good gait (mean gait score ≤2) or suboptimal gait (mean gait score >2). The relationship of pose features on d 33 with gait was analyzed using the data of 84 broilers (good gait: 57.1%, suboptimal gait: 42.9%). Birds with suboptimal gait had sharper hock joint lateral angles and lower hock-feet distance ratios during double support on d 33, on average. During steps, relative step height was lower in birds with suboptimal gait. Step height and hock-feet distance ratio showed the largest mean deviations in broilers with suboptimal gait compared to those with good gait. We demonstrate that pose estimation can be used to assess walking characteristics during a large part of the productive life of broilers, and to phenotype and monitor broiler gait. These insights can be used to understand differences in the walking patterns of lame broilers, and to build more sophisticated gait prediction models.

Bacterial chondronecrosis with osteomyelitis related Enterococcus cecorum isolates are genetically distinct from the commensal population and are more virulent in an embryo mortality model

Bacterial chondronecrosis with osteomyelitis (BCO) is a common cause of broiler lameness. Bacteria that are found in BCO lesions are intestinal bacteria that are proposed to have translocated through the intestinal epithelium and have spread systemically. One of the specific bacterial species frequently isolated in BCO cases is Enterococcus cecorum. In the current study, caecal isolates were obtained from birds derived from healthy flocks (12 isolates from 6 flocks), while isolates derived from caeca, colon, pericardium, caudal thoracic vertebrae, coxo-femoral joint, knee joint and intertarsal joint (hock) were obtained from broilers derived from BCO outbreaks (111 isolates from 10 flocks). Pulsed field gel electrophoresis was performed to determine similarity. Clonal E. cecorum populations were isolated from different bones/joints and pericardium from animals within the same flock, with intestinal strains carrying the same pulsotype, pointing to the intestinal origin of the systemically present bacteria. Isolates from the intestinal tract of birds from healthy flocks clustered away from the BCO strains. Isolates from the gut, bones/joints and pericardium of affected animals contained a set of genes that were absent in isolates from the gut of healthy animals, such as genes encoding for enterococcal polysaccharide antigens (epa genes), cell wall structural components and nutrient transporters. Isolates derived from the affected birds induced a significant higher mortality in the embryo mortality model as compared to the isolates from the gut of healthy birds, pointing to an increased virulence.

Modeling gait score of broiler chicken via production and behavioral data

Lameness in broilers may be associated with pain and is considered a major broiler production and welfare concern. Manual gait score assessment in commercial broiler houses is discrete, time-consuming, and laborious. As such, automatic methods for broiler gait score assessment are urgently needed. The objective of this study was to identify the relation of broiler gait score with several productions and behavioral metrics (bird BW, age, activity, and distribution), and establish three gait score prediction models for automatic gait score estimations in broiler farms with automatic weighing systems, camera systems, or both. Sixteen pens were used to rear Cobb 500 and Ross 708 broilers for eight and nine weeks, respectively (eight pens/strain, 12 birds/pen). The gait scores of all birds were assessed weekly by trained assessors following a six-point (0–5) scoring protocol from the third week. The pen’s average BW was measured weekly. Top-view cameras were installed to continuously record videos of broilers in all 16 pens. Images were extracted from video clips (10 min/hour) during a 16-hour light period to determine the activity index and distribution index through image processing. The gait score was positively correlated with BW (R2 = 0.97 for Cobb and R2 = 0.96 for Ross), while negatively correlated with activity (R2 = 0.78 for Cobb and R2 = 0.73 for Ross). The three models showed high accuracies in predicting broiler gait score based on variables of BW, age, activity index, and distribution index (R2 = 0.90–0.91, RMSE = 0.38–0.41). The findings of this study demonstrated the potential of estimating broiler gait score using bird BW, age, activity index, and distribution index. This information will assist in the development of automated gait score assessment systems in broiler production.

Provision of black soldier fly larvae (Hermetia illucens) in different ways benefits broiler welfare and performance, with largest effects of scattering live larvae

Including black soldier fly larvae (BSFL) in broiler diets has the potential to benefit broiler welfare and increase production performance, but the effects of dietary BSFL likely depend on the way BSFL are provided. In this study we aimed to discern the effects of different BSFL forms and provisioning methods by providing male broilers with no BSFL (CON), processed BSFL meal and oil incorporated in the feed pellets (INC-F), dried BSFL in the feeder on top of the feed (D-F), or dried or live BSFL scattered through the pen (D-S and L-S, respectively), and evaluating various indicators of broiler welfare and production performance. In all dietary BSFL treatments 8% of the total dietary dry matter content was replaced with BSFL. Dried and live larvae were provided in four equal daily portions at 08:00, 11:00, 14:00, and 17:00. Compared to a diet without BSFL, scattering dried or live larvae through the pen increased active behaviors, though only live larvae increased the time broilers spent standing. Broilers in the D-F, D-S and L-S treatments had higher average daily body weight gain during some periods, and they had higher final weights, despite L-S broilers having a lower total dry matter intake than CON broilers. Furthermore, the dry matter conversion ratio of INC-F, D-S and L-S broilers was reduced. At the end of the rearing period, pens in all dietary BSFL treatments had better litter quality than CON pens. Furthermore, food pad dermatitis was less severe for INC-F and D-S broilers than for CON broilers, and for L-S broilers than for broilers in all other treatments, and hock burn severity was less for L-S than for CON broilers. Broiler lameness, cleanliness, plasma natural antibody titers, and whole blood serotonin were not influenced by dietary BSFL treatment. Feather corticosterone concentrations were affected by treatment, though without any significant post-hoc differences. Our results indicate that BSFL meal and oil, and dried and live BSFL are all promising feed ingredients for broilers as they all benefit some aspects of broiler welfare and production performance. Scattering BSFL through the pen results in more welfare benefits than providing BSFL in the feeder, with live BSFL having the most beneficial effects on broiler welfare.

Morinda officinalis Polysaccharides Ameliorates Bone Growth by Attenuating Oxidative Stress and Regulating the Gut Microbiota in Thiram-Induced Tibial Dyschondroplasia Chickens.

Tibial dyschondroplasia (TD) occurs in chickens and other fast-growing birds, affecting their cartilage growth and leading to reduced meat quality in broilers. Morinda officinalis polysaccharide (MOP) is one of the chief active components of Morinda officinalis, which promotes bone formation, inhibiting bone loss and having anti-oxidant and anti-inflammatory properties. A total of 120 AA chickens were randomly divided into the CON group (basal diet), TD group (100 mg/kg thiram + basal diet), and MOP group (100 mg/kg thiram + basal diet + water with 500 mg/kg MOP). The experiment lasted 21 days. The results showed that MOP could alleviates broiler lameness caused by TD, restore the morphological structure of tibial growth plate (TGP), increase tibial weight (p < 0.05), balance the disorder of calcium and phosphorus metabolism, and promote bone formation by increasing the expression of BMP-2, Smad4, and Runx2 genes In addition, MOP supplementation stimulated the secretion of plasma antioxidant enzymes (T-SOD and GSH-Px) by regulating the expression of SOD and GPX-1 genes, thereby enhancing the antioxidant capacity of TD broilers. Interestingly, we observed MOP can also improve gut microbiota by increasing the beneficial bacteria count and decreasing the harmful bacteria count. These findings indicated that MOP can regulate bone formation through the BMP/Smads signaling pathway, attenuating oxidative stress and regulating the gut microbiota of TD broilers, so as to achieve the effect of treating TD. This suggests that MOP might be a potential novel drug in the treatment of TD in chickens.

Pose estimation-based lameness recognition in broiler using CNN-LSTM network

Poultry behavior is a critical indicator of its health and welfare. Lameness is a clinical symptom indicating the existence of health problems in poultry. Therefore, lameness detection in the early stages is vital to broiler producers. In this study, a pose estimation-based model was developed to identify lameness in broilers through analyzing video footages for the first time. A deep convolutional neural network was used to detect and track seven key points on the bodies of walking broilers. Then consecutive extracted key points were fed into Long Short-Term Memory (LSTM) model to classify broilers according to a 6-point assessment method. This paper proposes the first large-scale benchmark for broiler pose estimation, consisting of 9,412 images. In addition, the dataset includes 400 videos (36,120 frames in total) of broilers with different gait score levels. The developed LSTM model achieved an overall classification accuracy of 95%, and the average per class classification accuracy was 97.5%. The obtained results prove that the pose estimation-based model as an automatic and non-invasive tool of lameness assessment can be applied to poultry farms for efficient management.

Impact of experimentally induced bacterial chondronecrosis with osteomyelitis (BCO) lameness on health, stress, and leg health parameters in broilers

Stress and lameness negatively affect the health, production, and welfare of broilers. Bacterial chondronecrosis with osteomyelitis (BCO) is a leading cause of stress and lameness in commercial broilers. External changes in skin temperature related to changes in blood flow can be detected with infrared thermography (IRT), offering a noninvasive tool to assess the health of animals. This study compared physiological and noninvasive measures of stress and lameness in clinically healthy and lame male broiler chickens between 25 and 56 d. Birds were raised in pens within separate environmental chambers containing either litter flooring (sound) or wire flooring, with the latter established to induce BCO lameness (lame). Physiological and noninvasive measures of stress and lameness were collected: body weight, (BW), relative bursa weight, core body temperature, corticosterone (CORT) concentrations in serum and feathers, surface temperatures of the head (eye and beak) and leg (hock, shank, and foot) regions by infrared thermography (IRT), leg blood oxygen saturation (leg O2), and BCO lesion severity scores of tibial head necrosis (THN) and femoral head necrosis (FHN). Lame birds exhibited greater FHN and THN lesion severities, core body temperatures, and serum CORT (P < 0.05), but had lower BW, relative bursa weight, leg O2, and IRT surface temperatures of the beak, hock, shank, and foot compared with sound birds (P < 0.05). The difference in THN lesion severity between sound and lame birds decreased with age. Linear relationships between leg O2 with IRT leg surface temperatures were positive and negative between leg O2 with BCO lesion severity (P < 0.05). There were negative correlations between serum CORT with hock, shank and foot temperatures (P < 0.001), indicating that BCO is stressful. These results indicate that birds lame from BCO are stressed, have reduced oxygen saturation of blood in their legs, and that IRT surface temperatures can be used as noninvasive indicators of stress and lameness in broilers.

Lameness prediction in broiler chicken using a machine learning technique

Broiler flock welfare is usually assessed through mortality, physiology, behavior, and walking ability. The possibility of assessing broiler chicken lameness using the bird walking ability was investigated using the machine learning approach for the first time. Data on broiler walking speed and acceleration, genetic strain, and sex were recorded and input in a dataset. Broilers were classified according to the 6-point gait score (GS0 is a sound bird, and GS5 is a severely lame bird). Decision trees were built initially using all datasets. The confusion matrix of each developed model was analyzed. The pruning technique was used, removing from the dataset the variables that did not infer in the classification results. We reorganized the dataset and re-arranged the data by grouping the intermediate target class of gait score using the Borda Count method. Re-processing data, we obtained a new set of decision trees. Using the 3-point gait score (GS0 is a sound bird, and GS2 is a lame bird), we obtained a new model with better accuracy (78%); however, the model had a lower accuracy for classifying lame broilers (GS2, 5%). The final decision tree was selected for classifying broilers, either sound or lame, according to their walking speed. The developed model presented good accuracy (91%), and it ordered properly sound (86%) and lame birds (92%). The novel model might be used to assess broiler lameness on-farm by registering the bird displacement velocity. Further developments using the model might allow flock lameness detection automatically.

Chondronecrosis with osteomyelitis in broilers: further defining lameness-inducing models with wire or litter flooring to evaluate protection with organic trace minerals

The feed additive Availa-ZMC was investigated for the ability to reduce lameness in broilers using 2 alternative models for inducing lameness. The mixture of organic trace minerals was effective in reducing lameness by 20% in the wire flooring model and 25% in the litter flooring model with the bacterial challenge. Lameness in both models is overwhelmingly attributable to bacterial chondronecrosis with osteomyelitis. The reduction in lameness was associated, at least in part, with enhanced intestinal barrier integrity mediated by elevated expression of tight junction proteins and stimulation of bactericidal killing of adherent peripheral blood monocytes obtained from the birds treated with Availa-ZMC. Lameness is a major animal welfare concern in broiler production. The wire flooring model and litter flooring model with the bacterial challenge are effective models for evaluation of management strategies for mitigating infectious causes of lameness.

The utility of infrared thermography for evaluating lameness attributable to bacterial chondronecrosis with osteomyelitis

Bacterial chondronecrosis with osteomyelitis (BCO) is a leading cause of lameness in broilers. Infrared thermography (IRT) is a noninvasive technique for measuring infrared radiation from an object and can be used to evaluate clinical health. Two replicated studies compared the effect of light intensity on broilers grown on a wire flooring model that experimentally increased their susceptibility to and incidence of BCO lameness. Day-of-hatch male broiler chickens were placed into 6 pens on wood shavings litter, and at 1 wk one of 3 light intensity treatments (2, 5, or 10 lux) was allotted. At 4 wk half of the population from each pen was moved to a pen with wire flooring and the same light intensity. At 1, 4, 5, and 8 wk, an IRT image of the legs of 5 clinically healthy broilers from each pen was taken. The right and left proximal femora and tibiae of sound and lame broilers were scored for femoral head necrosis (FHN) and tibial head necrosis (THN) lesion severity. There were minimal effects of light intensity and flooring. In Study 1, but not Study 2, broilers on wire flooring weighed less on day 38 (P = 0.007) and days 57 to 58 (P = 0.003) compared to those on litter. The proportion of broilers that became lame on wire flooring was 52% in Study 1 and 14% in Study 2. The proportion of sound broilers from litter and wire flooring pens with subclinical signs of BCO in their right or left proximal growth plates was over 45% for FHN and 92% for THN, and lame broilers had more severe (P < 0.0001) FHN and THN compared to sound broilers. IRT surface temperatures of the hock joint, shank, and foot were consistently lower (P < 0.0001) in broilers that became lame when compared to sound. Therefore, IRT surface temperatures of broiler leg regions may be useful for detecting lesions attributed to BCO.

Bioavailability of a novel form of silicon supplement

In this study, we assessed uptake and potential efficacy of a novel, pH neutral form of silicon supplement in vitro and using broiler chickens as a model species. In vitro bioavailability of this supplement was significantly higher than other commercial supplements tested, all of which claim available silica content. To confirm bioavailability of the new supplement in vivo, a broiler chick feeding trial reported blood uptake that was significantly higher than a Bamboo-derived silicon supplement. We assessed dose response of the novel supplement in a further study with increased dose related levels of silicon being detected in the blood and tibia. We found tibia and foot ash residue as a percentage of dry mass was higher with inclusion of the novel supplement in the diet, particularly in young birds and that this was followed by significant increase in tibia breaking strength. This novel supplement may therefore have applications in the improvement of bone integrity, with implications for the reduction of lameness in broilers. These results indicate the novel silica supplement is readily absorbed in chicks, and transported in the blood supply to sites such as the skeleton due to it being present in a non-condensed, monomeric form. There is potential for wider application of this silica supplement in other species where bone breakages are a problem, including high performance sport.

Effects of environmental enrichment on activity and lameness in commercial broiler production

ABSTRACTThe aim of this pilot study was to investigate the effects of commercially applied environmental enrichments on behavior and lameness in broilers. Two consecutive flocks of broilers were observed at 16 days and 30 days of age to investigate differences between enriched (peat, bales of lucerne hay, and elevated platforms) and control birds with regards to behavioral activities and lameness. More running (p < .001), worm running (p = .006), play fighting (p = .015), dust bathing (p = .009), and ground pecking while standing (p < .001) were observed at 16 days than at 30 days. Across both ages, enriched birds showed more wing flapping (p = .016), wing stretching (p = .002), body shaking (p = .002), ground scratching (p < .001), and ground pecking while standing (p < .001) and lying (p = .003) compared with control birds. Even when no enrichments were close, enriched birds showed more body shaking (p = .008) and ground pecking while standing (p < 0.001) and lying (p = .010) than birds in comparable locations in control pens. There was a tendency for a lower gait score (i.e., reduced lameness) with the enriched treatment (p = .077). In conclusion, enriched birds showed higher levels of several activities compared with control birds, and demonstrated higher levels in areas where no enrichments were present.

Drum Evaluation of Broilers Over 20 Years of Selection

ObjectivesAs a result of genetic selection pressures, economically important traits continue to make gains in fast growing boilers. To understand the impact that has taken place over time on profitable traits, such as live weight, as well as indirectly selected traits, whole leg and tibia parameters of 2 genetic broiler lines representing the 1995 and 2015 broiler maintained at the University of Arkansas were compared.Materials and MethodsOne hundred 20 broilers, evenly split between the 1995 RAN and 2015 RAN lines, were reared straight-run with ab libitum access to industry standard feed and water (IACUC Approval #15039). Fifteen birds were weighed, then euthanized at each time point from each line (d 0, d 14, d 28, and d 42). Left legs were disarticulated, weighed and cleaned of flesh and tendons. The following tibia measurements were collected; tibia weight, tibia lengths, proximal width-frontal, distal width-frontal, midpoint width, proximal width-sagittal, distal width-sagittal. Max load, load break, load extension, and compressive strain was calculated for d 14, d 28, and d 42 using an Instron Universal Testing Machine (IUTM). Spacing used for IUTM test are as follows: 2 cm for d 14, 4 cm for d 28, 5 cm for d 42. To compare means between data collected for each age of both lines, JMP Pro v. 12 was used though t tests with a significance level (p < 0.05).ResultsBody weight was significantly larger in 2015 RAN line compared to 1995 RAN at ages d 14, d 28, and d 42. Tibia weight was significantly smaller in the 2015 RAN line at d 0 (p = 0.0304), but surpassed the RAN 1995 line at d 14 of age (p = 0.0206). Mean weight was not significantly different between the 2 lines at d 28 and d 42. Mean leg weight to body weight ratio is significantly larger in the 1995 line on d 0 and d 28 (p = 0.0031 and p = 0.0290, respectively), and indicate no significant differences on d 24 or d 42. This trend is also seen in tibia weight to body weight ratio being significantly larger in the 1995 line on d 0 and d 28 (p = 0.0170 and p = 0.0070, respectively). Drum weight to body weight ratio indicate significantly larger ratios for 1995 RAN line on d 0 (p = 0.0008), but this trend does not continue in older ages. Dimensional ratios of tibia proximal width (sagittal) to tibia length (p = 0.0370), tibia distal width (sagittal) to tibial length (p = 0.0118), and tibial midpoint width to tibial length (p = 0.0161) all indicate significantly larger ratios in d 0 1995 RAN compared to d 0 2015 RAN lines, but this trend does not continue in older ages. No differences were detected in the max load, load at break, load extension, and compressive strain force measures.ConclusionInterestingly, many of the parameter reported indicated that at day of hatch, broilers of the 2015 RAN have reduced size associated with the tibia. Allocations of nutrients during embryonic development may be contributing to the discrepancy in birds between the 2 lines at d 0 and can act as a focus in future genetic selections aimed to reduce the incidence of lameness in broilers.

Paraconsistent logic used for estimating the gait score of broiler chickens

Visually estimating the gait score in a flock is not a precise task. The evaluation is done based on scores from 0 (sound bird) to 5 (lame bird). The extremes are easily identifiable; however, the intermediate scores are not evident. This study aimed to develop an algorithm and software to estimate broiler gait score. Video images were recorded from broilers walking on a special platform. The walkway was covered with bedding substrate. A blue panel provided a background to contrast with the birds. Selected broilers from the different gait scores were placed to walk on the runway, and a video was recorded. An algorithm was developed to analyse the video streams. The centroid of the chicken body was detected, through which the broiler's speed, and acceleration from gait score were calculated. The velocity and acceleration data were analysed using paraconsistent logic, and an algorithm was developed. The software was able to predict the intermediate values of broiler gait score with a low degree of uncertainty, given the broiler velocity and acceleration. For the estimation of GS 1, we obtained 50% accuracy. For GS 2 the estimation was 70% precise, and for GS 3, the results were 100% accurate. During the auditing of the flock welfare process, the intermediate results of broiler gait score are visually difficult to identify. Using the developed software it might be possible to detect lameness in broilers under commercial rearing since the velocity of displacement can be easily measured and used as input data by the growers.

Exploring the economic potential of reducing broiler lameness

ABSTRACT1. The present study was designed first to explore the potential economic benefits of adopting management practices to reduce lameness in broiler farms, and second to explore farmers’ possible perceptions of this potential in the Swedish context. The likely financial effects were addressed using a normative economic model, whereas a questionnaire-based survey was used to obtain in-depth knowledge about the perceptions of a group of broiler farmers in Sweden.2. The three alternative practices (out of 6 tested) which realised the greatest improvements in gross margin and net return to management compared to the conventional practice were feeding whole wheat, sequential feeding and meal feeding.3. The model showed that the negative effect of feeding whole wheat on feed conversion rate was outweighed by the effect of a low feed price and the associated decrease in feed costs. The price of wheat played a major role in the improvement of economic performance, whereas the reduction of lameness itself made a relatively minor contribution.4. Apparently, the surveyed farmers do not recognise the potential of the positive effects of changing feed or feeding practices on both broiler welfare and farm economics although their implementation can be of great importance in the broiler sector where profit margins are very tight.​