The autologous chondral platelet-rich plasma matrix implantation. A new therapy in cartilage repair and regeneration: macroscopic and biomechanical study in an experimental sheep model

Introduction

Articular cartilage injuries are a severe problem, and the treatments for these injuries are complex. The present study investigates a treatment for full-thickness cartilage defects called Autologous Chondral Platelet Rich Plasma Matrix Implantation (PACI) in a sheep model.

Methods

Chondral defects 8 mm in diameter were surgically induced in the medial femoral condyles of both stifles in eight healthy sheep. Right stifles were treated with PACI and an intraarticular injection with a plasma rich in growth factors (PRGF) solution [treatment group (TRT)], while an intraarticular injection of Ringer's lactate solution was administered in left stifles [Control group (CT)]. The limbs' function was objectively assessed with a force platform to obtain the symmetry index, comparing both groups. After 9 and 18 months, the lesions were macroscopically evaluated using the International Cartilage Repair Society and Goebel scales.

Results

Regarding the symmetry index, the TRT group obtained results similar to those of healthy limbs at 9 and 18 months after treatment. Regarding the macroscopic assessment, the values obtained by the TRT group were very close to those of normal cartilage and superior to those obtained by the CT group at 9 months.

Conclusion

This new bioregenerative treatment modality can regenerate hyaline articular cartilage. High functional outcomes have been reported, together with a good quality repair tissue in sheep. Therefore, PACI treatment might be a good therapeutic option for full-thickness chondral lesions.

Modification of Domestic Animal Lameness Scales for Use in Asiatic Black Bears (Ursus thibetanus)

Lameness in animals is a welfare concern as it can be an indicator of pain. A standardized bear lameness scale would significantly improve the ability of facilities that house bears to monitor, manage, and treat lameness in their animals. The Animals Asia bear rescue center in Vietnam holds over 180 rescued bears with varying health and mobility conditions as a result of the illegal bear bile trade, and a reliable lameness assessment system was needed. Bear locomotion includes a lumbering gait, which differs from domestic animal locomotion, necessitating the modification of domestic animal lameness scales, and a five-point lameness scale was developed. Professionals from various veterinary-related backgrounds scored bear lameness videos to assess interobserver reliability and the intraclass correlation coefficient indicated good to excellent reliability. A 15-min training video with examples of lameness and grades was provided before assessment. The lameness scale developed herein addresses the lack of a published lameness scale for bears, and, due to the similar locomotion of the genus, can be used on any bear species. This scale is a consistent and reliable tool for evaluating and documenting lameness in addition to monitoring response to treatment. It will benefit bear welfare by indirectly characterizing the level of pain a bear is experiencing due to lameness as well as serving to document trends in pain status.

Optimal lameness induction model development using amphotericin B in meat goats

Lameness continues to be a critical health and welfare concern associated with goat production. Amphotericin B (amp B) is an antimicrobial successful in inducing transient lameness for research purposes previously in livestock animals. The objectives of this study were to (1) identify which of three varying doses of amp B would be most effective in inducing lameness in meat type goats and (2) develop a facial grimace scale for goats. Lameness was produced by an intra-articular injection of amphotericin B into the left hind lateral claw distal interphalangeal joint with either a 5 mg/0.25 mL (high-low, 5 mg of amphotericin B in a volume of 0.25 mL), 5 mg/0.5 mL (high-high, 5 mg of amphotericin B in a volume of 0.5 mL), or a 2.5 mg/0.25 mL (low-low, 2.5 mg of amphotericin B in a volume of 0.25 mL). A saline treatment of 0.5 mL was used as control (0.9% sterile saline solution). Lameness response was analyzed by infrared thermography (IRT) at the induced joint, mechanical-nociception threshold (MNT), visual lameness scoring (VLS), a visual analogue scale (VAS), kinetic gait analysis (KGA), plasma cortisol (CORT), substance P (Sub P), and behavior scoring. The IRT and MNT values differed by timepoint (P ≤ 0.0001). Results from VLS showed the HL treatment was the most effective at inducing lameness (6/6 goats became lame compared to HH 4/6 and LL 2/6). At 24, 48, and 72 h, VAS scores were significantly higher when comparing HL to all other treatment groups (P = 0.0003). Both behavior observers (1 and 2) reported a significant time effect (P = 0.05), with goats exhibiting more facial grimacing at 24 h post-lameness induction. From these data, an optimal dose for a repeatable lameness induction model in goats was aquired. An effective Goat Grimace Scale (GGS) was also developed to evaluate pain responses in goats.

The Effect of Lameness on Milk Production of Dairy Goats

Lameness on dairy goat farms is a welfare concern and could negatively affect milk production. This study's objective was to evaluate the effects of clinical lameness on the daily milk production of dairy goats. Between July 2019 and June 2020, 11,847 test-day records were collected from 3145 goats on three farms in New Zealand. Locomotion scoring of goats used a five-point scoring system (0 to 4). The dataset was split into two groups by lactation type, where goats were classified as being in seasonal lactation (≤305 days in milk) or extended lactation (>305 days in milk). A linear mixed model was used to analyze datasets using milk characteristics as the dependent variables. Severely lame goats (score 4) in seasonal and extended lactation produced 7.05% and 8.67% less milk than goats not lame, respectively. When the prevalence of severe lameness is between 5 and 20% of the herd, the estimated average daily milk income lost was between NZD 19.5 and 104 per day. This study established the negative impact of lameness on milk production and annual income in dairy goats on three farms.

Long-term effects of early maternal deprivation on goat social behaviour

Early maternal deprivation has been shown to disrupt goat kids' social behaviour and stress-coping strategy, and has long-term effects in other species like cattle. We studied the long-term effects of early maternal deprivation on 18-month-old goats. Seventeen goats were raised together with their dams (DR kids) and other lactating goats and kids, while 18 goats were separated from their dams three days after birth and artificially reared together (AR kids). Kids of both treatments were weaned around two to three months of age, grouped and raised together until this study 15 months later. Affiliative, playful, and agonistic behaviour was recorded by focal sampling in the home pen, when the focal goat had rejoined the herd after being physically isolated for 3 minutes, and after the focal goat was restrained and manipulated for 3 minutes. Behavioural observations were also conducted after the goats were introduced in groups of four in a herd of 77 unknown, lactating multiparous goats. Avoidance distance tests were performed in the home pen to assess the human-animal relationship. Salivary cortisol was measured before and after physical isolation, and faecal glucocorticoid metabolites were measured before and 24 hours after introduction in the lactating herd. In the home pen, AR goats were involved in less head nudging than DR goats, but other social behaviours or their behavioural and physiological response to the various stressful situations were not affected by their rearing treatment. Upon introduction in a DR lactating herd, most of the agonistic interactions observed were initiated by multiparous goats towards the introduced AR and DR goats alike. AR goats received more threats from the multiparous goats than DR goats, but were involved in less clashing than DR goats. AR goats showed less avoidance of familiar and unfamiliar humans than DR goats. Overall, previously AR and DR goats showed only a few differences in affiliative and agonistic behaviours in their home pen or after being exposed to different stressors 15 months later. Nonetheless, after being introduced into a multiparous goat herd, AR goats were still threatened more often than DR goats, and DR goats clashed more than AR goats, suggesting some persistent differences in their social abilities observed at an early age before and after weaning. As predicted, AR goats remained less fearful of humans than DR goats.

Estimates of Genetic Parameters for Milk, the Occurrence of and Susceptibility to Clinical Lameness and Claw Disorders in Dairy Goats

The New Zealand goat industry accesses niche markets for high-value products, mainly formula for infants and young children. This study aimed to estimate the genetic parameters of occurrence and susceptibility of clinical lameness and selected claw disorders and establish their genetic associations with milk production traits. Information on pedigree, lameness, claw disorders, and milk production was collected on three farms between June 2019 and July 2020. The dataset contained 1637 does from 174 sires and 1231 dams. Estimates of genetic and residual (co)variances, heritabilities, and genetic and phenotypic correlations were obtained with uni- and bi-variate animal models. The models included the fixed effects of farm and parity, deviation from the median kidding date as a covariate, and the random effects of animal and residual error. The heritability (h²) estimates for lameness occurrence and susceptibility were 0.07 and 0.13, respectively. The h² estimates for claw disorder susceptibilities ranged from 0.02 to 0.23. The genotypic correlations ranged from weak to very strong between lameness and milk production traits (-0.94 to 0.84) and weak to moderate (0.23 to 0.84) between claw disorder and milk production traits.

Lesions found at foot trimming of dairy goats: Baseline data for comparing lesions and locomotion scoring

Data on the foot lesions of housed dairy goats, especially those that are not lame, is sparse. In this study, visits were made to four farms for whole herd locomotion scoring after milking and to observe routine foot trimming. During trimming, the amount of trimming required for each hoof was recorded, alongside the presence of lesions. The process was repeated at the next routine foot trim on three of the four farms (on Farm 1 whole herd locomotion scoring after milking was not feasible). Across both visits, 3445 locomotion scores were recorded, alongside 3850 trimming and lesion records. There were large differences between farms and visits in the proportion of lame goats (6.7 to 25.5%) and in the proportion of goats which needed a substantial trim of all four feet (15.1-33.1%). Hoof lesions were observed in 65.5% of trimmed goats. We defined lesions by their site and presence of separation and/or granuloma, with white line separation being the most commonly recorded lesion (41.5% of goats). On all visits on the three farms which were locomotion scored, the number of goats recorded as lame was lower than the number observed with white line lesions, but the relative proportion ranged from 17% to 95.4%. Separations were much more common than granulomas, as granulomas were usually accompanied by separation. Toe lesions were much more likely to be associated with granulomas than white line lesions, with 91.5% of toe separations having granulomas but only 10.6% of white line separations. This study provides useful baseline data for comparing lesions and locomotion scoring between goat herds but also identifies areas where we need more data and more consensus.

Animal-Based Indicators for On-Farm Welfare Assessment in Goats

Simple Summary

Welfare assessments for animals require the use of specific indicators. These indicators should be practical and easy to use in an on-farm environment while correctly reflecting on the animals’ welfare. Our aim was to review literature on such indicators for goats, as small ruminants have not received as much attention as other farm animals in the field of welfare assessment. Some indicators such as lameness are already well investigated and suitable for use in goat welfare assessments. Others, for example, lying behaviour, need more research, as the limited amount of knowledge restrains the information on validity or usefulness. As in other animals, the welfare of goats has become an increasingly important issue in public discourse. Our overview on indicators aids in developing tools to measure and improve the welfare of goats.

Abstract

This review describes the current state of knowledge relating to scientific literature on welfare indicators for goats. Our aim was to provide an overview of animal-based indicators for on-farm welfare assessments. We performed a literature search and extracted 96 relevant articles by title, abstract, and full-text screening. Out of these articles, similar indicators were aggregated to result in a total of 32 welfare indicators, some of which were covered in multiple articles, others in only a single one. We discuss a set of three established assessment protocols containing these indicators, as well as all individual indicators which were covered in more than one article. As single indicators, we identified lameness, body condition score (BCS), qualitative behaviour assessment (QBA), and human–animal relationship (HAR) tests with substantial evidence for sufficient validity to assess welfare in goats. A multitude of indicators (e.g., hair coat condition) was studied less intensively but was successfully used for welfare assessments. For some indicators (e.g., oblivion, lying behaviour), we highlight the need for future research to further validate them or to optimise their use in on-farm welfare assessments. Moreover, further investigations need to include kids, bucks, and meat and fibre goats, as well as extensively kept goats as the literature predominantly focuses on dairy goats in intensive production systems.

Welfare Assessment of 30 Dairy Goat Farms in the Midwestern United States

Dairy goat animal welfare assessment protocols have been developed and conducted in Europe and the United Kingdom for dairy goats; however, there are no published reports of large-scale welfare assessment for dairy goats on farms in the Midwestern United States (US). Therefore, the objective of this study was to perform welfare assessment of lactating dairy goats and identify the most prevalent welfare issues on 30 farms across the Midwestern US. Thirty dairy goat farms (self-selected) were enrolled in the study if they shipped milk for human consumption (regardless of herd size). The number of lactating does on each farm ranged from 34 to 6,500 goats, with a median number of 158 lactating does (mean ± SD: 602 ± 1,708 lactating does). The protocol used was developed from available literature on goat welfare assessment but modified for use in the Midwestern US. Observations were made without handling the animals and included 22 animal-based indicators evaluated at the group- and individual-level. The observations were conducted during ~3-5 h during a milking session (either morning or afternoon) and time in the home pen. Principal components analysis (PCA) was carried out on the welfare assessment data from each farm. The first two dimensions of the PCA explained 34.8% of the variation. The PCA biplot indicated correlations between indicators. The most prevalent conditions observed across the 30 farms included any knee calluses (80.9%), any claw overgrowth (51.4%), poor hygiene (14.9%), skin lesions (8.9%), poor hair coat condition (8.3%) and any ear pathology (8.0%). These results are the first to provide the Midwestern US dairy goat industry with information to improve commercial dairy goat welfare.

Hoof Pressure Distribution Pattern of Blue Sheep During Walking on Different Slopes: A Subject-Specific Analysis

The purpose of this study was to quantitatively assess the vertical force distribution (VFD) of subject-specific healthy blue sheep while walking on different slopes using a pressure-sensing walkway. The blue sheep was trained to walk over the pressure-sensing walkway by choosing a comfortable walking speed, and the slope angle increased from 0° to 25°. The sheep's hooves were divided into four quadrants, namely, the cranio-lateral, cranio-medial, caudo-lateral, and caudo-medial quadrants, to investigate the VFD of the peak vertical force (PVF), vertical impulse (VI) and occurrence time of the PVF during the stance phase (TPVF). This study demonstrates that the main stressed quadrant of the front hoof changes from the caudo-medial quadrant to the cranio-medial quadrant with increasing slope. The main stressed quadrant of the rear hoof is the cranio-medial quadrant and does not change with the increasing slope. For all the slopes, the vertical force shifted from the lateral quadrant to the medial quadrant and from the caudal quadrant to the cranial quadrant. All the results obtained in the study suggest the feasibility of detecting gait changes in blue sheep, which has potential for the diagnosis of lower limb musculoskeletal diseases in quadrupeds.

Evaluating the Welfare of Small Ruminants: Practical Management Advice

This article discusses key welfare issues for small ruminants and gives practical management advice. Welfare assessment is vital to ensure that optimal conditions are provided. Practitioners can play a key role in identifying areas of potential welfare compromise and implement interventions. With the knowledge and careful identification of indicators of welfare, practitioners and producers can develop a management plan that can ensure proper nutrition, environment, and health to allow for natural behaviors and a positive affective state; identification of animal health and management issues; and (3) allocation of adequate resources to improve the welfare of sheep and goats.

Development and evaluation of two different lameness models in meat goats, a pilot study

Lameness is a serious health concern for livestock species. Understanding individual animal response to pain and characterization of lameness are critical when developing appropriate treatments. The objectives of this pilot study was to evaluate two different lameness models and measures for determining response to induced lameness in meat goats. Lameness was induced by intraarticular injection into the left hind lateral claw distal interphalangeal joint with either amphotericin B (Amp-B) or kaolin-carrageenan (K-C). Response to lameness was characterized by behavior scoring, visual lameness scoring (VLS), infrared thermography (IRT) of the affected digit, pressure mat gait analysis (PMT), and plasma cortisol (CORT) analysis. Lame goats had higher VLS compared to controls (P = 0.003). Maximum temperatures measured in hooves from lame vs control goats were significantly higher (P = 0.003). Pressure mat analysis demonstrated, when compared to controls, lame goats had decreased force (P = 0.013), impulse (P = 0.007), contact pressure (P = 0.007), and contact area of the left hind limb (P = 0.009). Mean CORT levels 4 and 6 h after lameness induction were higher in lame goats (P = 0.005, P = 0.01). The two lameness methods reliably induced lameness of varying severity in healthy meat goats.

Use of a pressure-sensing walkway system for biometric assessment of gait characteristics in goats

The purpose of this study was to quantitatively assess gait characteristics and weight-bearing forces during ambulation in goats free of lameness using a pressure-sensing walkway as a biometric tool for stride, gait, and force analysis. Forty-six non-lame adult goats ranging in age from 5 to 6 years, mixed-breeds, and with a mean body weight of 52 ± 7.1 kgs were used. Goats were trained to walk over a pressure-sensing walkway. Data for analysis was collected on 2 different days, 3 days apart. On each day, 2 to 5 walking passes, in the same direction, were captured for each goat. Data from 2 valid passes meeting the criteria for consistent walking gait on each day were averaged then used for analysis. Analysis was performed, including the day-effect, for stride, gait, and force characteristics. Of the 46 goats enrolled in the study, complete data sets were achieved in 33 (72%) goats. Gait biometrics were similar among the assessment days; therefore, all data was pooled for the purpose of characterizing data for individual limb and biometric parameter comparisons at the individual goat level. Statistical analysis revealed that no difference within the paired limbs, and that there were significant differences between the front limbs and hind limbs. Maximum force and maximum peak pressure were significantly greater for the front limbs as compared with the hind limbs (p < 0.001). Based on the results, gait and force characteristics can be consistently measured in goats using a pressure-sensing walkway during a consistent walking gait. Goats apply greater force to the forelimbs during the weight-bearing phase of stride as compared with the hind limbs. The use of objective assessment tools is expected to improve the ability of researchers and clinicians to monitor changes in weight bearing and gait and will contribute to improved animal welfare.