Tracking individual broilers on video in terms of time and distance.

Tracking group-housed individual broilers using video can provide valuable information on their health, welfare, and performance, allowing breeders to identify novel or indicator traits that aid genetic improvement. However, their similar appearances make tracking individual broilers in a group-housed setting challenging. This study aimed to analyze broiler tracking on video (number of ID-switches, tracking time and distance) and examined potential tracking errors (ID-losses - location, proximity, kinematics) in an experimental pen to enable broiler locomotion phenotyping. This comprehensive analysis provided insights into the potential and challenges of tracking group-housed broilers on video with regards to phenotyping broiler locomotion. Thirty-nine broilers, of which 35 noncolor marked, were housed in an experimental pen (1.80 × 2.61 m), and only data at 18 d of age were used. A YOLOv7-tiny model was trained (n = 140), validated (n = 30), and tested (n = 30) on 200 annotated frames to detect the broilers. On the test set, YOLOv7-tiny had a precision, recall, and average precision (@0.5 - Intersection over Union threshold) of 0.99. A multi-object tracker (SORT) was implemented and evaluated on ground-truth trajectories of thirteen white broilers based on 136 min of video data (1-min intervals). The number of ID-switches varied from 5 to 20 (mean: 9.92) per ground-truth trajectory, tracking times ranged from 1 (by definition) to 51 min (mean: 12.36), and tracking distances ranged from 0.01 to 17.07 meters (mean: 1.89) per tracklet. Tracking errors primarily occurred when broilers were occluded by the drinker, and relatively frequently when broilers were in close proximity (within 10 cm), with velocity and acceleration appearing to have a lesser impact on tracking errors. The study establishes a 'baseline' for future research and identified the potential and challenges of tracking group-housed individual broilers. The results highlighted the importance of addressing ID-switches, identified potential tracking algorithm improvements, and emphasized the need for an external animal identification system to enable objective, simultaneous and semi-continuous locomotion phenotyping of group-housed individual broilers.

Passive radio frequency identification and video tracking for the determination of location and movement of broilers.

Phenotypes on individual animals are required for breeding programs to be able to select for traits. However, phenotyping individual animals can be difficult and time-consuming, especially for traits related to health, welfare, and performance. Individual broiler behavior could serve as a proxy for these traits when recorded automatically and reliably on many animals. Sensors could record individual broiler behavior, yet different sensors can differ in their assessment. In this study a comparison was made between a passive radio frequency identification (RFID) system (grid of antennas underneath the pen) and video tracking for the determination of location and movement of 3 color-marked broilers at d 18. Furthermore, a systems comparison of derived behavioral metrics such as space usage, locomotion activity and apparent feeding and drinking behavior was made. Color-marked broilers simplified the computer vision task for YOLOv5 to detect, track, and identify the animals. Animal locations derived from the RFID-system and based on video were largely in agreement. Most location differences (77.5%) were within the mean radius of the antennas' enclosing circle (≤128 px, 28.15 cm), and 95.3% of the differences were within a one antenna difference (≤256 px, 56.30 cm). Animal movement was not always registered by the RFID-system whereas video was sensitive to detection noise and the animal's behavior (e.g., pecking). The method used to determine location and the systems' sensitivities to movement led to differences in behavioral metrics. Behavioral metrics derived from video are likely more accurate than RFID-system derived behavioral metrics. However, at present, only the RFID-system can provide individual identification for non-color marked broilers. A combination of verifiable and detailed video with the unique identification of RFID could make it possible to identify, describe, and quantify a wide range of individual broiler behaviors.

A proteomics-based identification of putative biomarkers for disease in bovine milk.

The objective of this study was to identify and characterize potential biomarkers for disease resistance in bovine milk that can be used to indicate dairy cows at risk to develop future health problems. We selected high- and low-resistant cows i.e. cows that were less or more prone to develop diseases according to farmers' experience and notifications in the disease registration data. The protein composition of milk serum samples of these high- and low-resistant cows were compared using NanoLC-MS/MS. In total 78 proteins were identified and quantified of which 13 were significantly more abundant in low-resistant cows than high-resistant cows. Quantification of one of these proteins, lactoferrin (LF), by ELISA in a new and much larger set of full fat milk samples confirmed higher LF levels in low- versus high-resistant cows. These high- and low-resistant cows were selected based on comprehensive disease registration and milk recording data, and absence of disease for at least 4 weeks. Relating the experienced diseases to LF levels in milk showed that lameness was associated with higher LF levels in milk. Analysis of the prognostic value of LF showed that low-resistant cows with higher LF levels in milk had a higher risk of being culled within one year after testing than high-resistant cows. In conclusion, LF in milk are higher in low-resistant cows, are associated with lameness and may be a prognostic marker for risk of premature culling.

Phenotypic and genetic relationships of bovine natural antibodies binding keyhole limpet hemocyanin in plasma and milk.

To improve the health status (resilience) of dairy cows, levels of natural antibodies (NAb) might be useful. The objective of the present study was to compare levels and to estimate genetic parameters for NAb measured in milk and plasma samples. Titers of NAb IgM and IgG isotype-binding keyhole limpet hemocyanin of 2,919 cows, in both plasma and milk, were measured using ELISA. Analysis revealed that NAb levels in milk significantly increased with parity, whereas they remained constant in plasma. Moderate positive phenotypic correlations were found between NAb levels in milk and in plasma: 0.18 for IgG and 0.40 for IgM. This indicates that NAb from milk and plasma might reflect different aspects of dairy cow health status. However, high genetic correlations were found for NAb in milk and plasma: 0.81 for IgG and 0.79 for IgM. Heritabilities (SE in parentheses) for NAb measured in plasma [0.15 (0.05) for IgG and 0.25 (0.06) for IgM] were higher than heritabilities of NAb measured in milk [0.08 (0.03) for IgG and 0.23 (0.05) for IgM]. Our results indicate that NAb measured in milk and plasma are heritable and likely have a common genetic background, suggesting that NAb levels measured in milk might be useful for genetic improvement of disease resistance.

Crepitus is a first indication of patellofemoral osteoarthritis (and not of tibiofemoral osteoarthritis).

OBJECTIVE: The patellofemoral joint (PFJ) is important in early detection of knee osteoarthritis (OA). Little is known about the relationship between specific clinical findings and PFJ Magnetic resonance Imaging (MRI) features. The objective was to examine the relationship between (early) clinical findings and PFJ MRI features in females (45-60 years) without knee OA (PFJ or tibiofemoral joint (TFJ) OA) based on a recently suggested MRI definition. METHODS: MRIs of knees of women of a sub-study of the Rotterdam Study were scored with semi-quantitative scoring. Specific patellar tests were performed on physical examination. Current knee pain and history of patellar knee pain were reported. Binomial logistic generalized estimated equations were used to determine the association between clinical findings of OA and PFJ MRI features. All associations were adjusted for age, body mass index (BMI) and TFJ MRI features. RESULTS: In 888 women (1776 knees, mean age: 55.1 years and mean BMI: 27.0 kg/m(2)) we found significant associations between crepitus and all PFJ MRI features (Odds ratios (OR) range: 2.61-5.49). A history of patellar pain was significantly associated with almost all PFJ MRI features (ORcartilage: 1.95; ORcysts: 1.86; ORbone marrow lesions: 1.83), except for osteophytes. No significant associations were found between the clinical findings and TFJ MRI features. CONCLUSION: Crepitus and history of patellar pain are clinical findings that indicate PFJ lesions seen on MRI. These tests could help to indicate signs of PFJOA. Follow-up data needs to confirm whether these tests have an additional diagnostic value for early knee OA in PFJ or TFJ.

Development of radiological knee osteoarthritis in patients with knee complaints.

OBJECTIVES: It is currently impossible to identify which patients with knee complaints presenting to the general practitioner will develop knee osteoarthritis (OA) pathology at a later stage. This study examines the determinants for developing OA pathology on x-ray in patients with knee complaints but no radiological OA at baseline in the painful knee. METHODS: Data from the prospective Rotterdam cohort study (including subjects aged ≥55 years) were used. Analysis was performed on 623 subjects with knee complaints at baseline and their data at 6-year follow-up (T1; n=607) and at 11-year follow-up (T2; n=457). At baseline, none had radiological OA (rOA=Kellgren and Lawrence (KL) grade ≥2) in the painful joint. At follow-up, predictors for rOA were determined using multivariate ordinal logistic regression analysis. RESULTS: At T1, 8.5% of the group had developed knee rOA and, by T2, this had increased to 23%. Determinants remaining significant in the multivariate analysis were female gender (OR 1.95, 95% CI 1.15 to 3.36), other joint complaints (OR 2.22, 95% CI 1.12 to 4.35) and KL grade 1 at baseline in the painful knee joint (OR 7.14, 95% CI 4.55 to 11.1). All outcomes are adjusted for all included determinants. CONCLUSION: The best predictors of development of knee rOA are a combination of female gender, other joint complaints and KL grade 1 in the painful joint. KL grade 1 in combination with knee pain should be considered as early OA in patient management.

Impact of different descriptions of the Kellgren and Lawrence classification criteria on the diagnosis of knee osteoarthritis.

OBJECTIVES: Although the Kellgren and Lawrence (K&L) criteria for defining radiological osteoarthritis are widely used in epidemiological and clinical studies, the authors previously documented the existence of five different versions of these criteria. This study identifies the impact of the use of alternative versions of the K&L criteria and evaluates which description has the highest association with knee complaints. METHODS: Two readers scored most radiographs of the knees of participants of the Rotterdam Study with the original K&L description (90%). In addition, each alternative description was used in a random part (20%) of the radiographs. The authors calculated reproducibility of all descriptions, and compared sensitivity and specificity of the alternative descriptions for three cut-off points with the original description as reference standard (K&L≥1, K&L≥2 and K&L≥3). The authors calculated κ statistics to compare agreement between the original and alternative descriptions, and evaluated the association with knee complaints. RESULTS: The dataset comprises radiographs of knees of 3071 people. For cut-off K&L≥1 all four alternatives classified more people as having osteoarthritis than the original description; κ was low, and sensitivity and specificity were moderate to good. For cut-offs K&L≥2 and K&L≥3 there was little difference in the number of cases and κ, sensitivity and specificity were good to perfect. The original description and alternative 3 showed the strongest association with knee complaints. CONCLUSIONS: The different descriptions of the K&L criteria have impact on the classification of osteoarthritis in the lowest grade (K&L≥1). All descriptions have strengths and weaknesses. It depends on the purpose which is the best description.

Limited evidence for a protective effect of unopposed oestrogen therapy for osteoarthritis of the hip: a systematic review.

Above the age of 50 yrs, the incidence of OA rises steeply in women but less in men, suggesting an association with changes in female hormone levels in the menopause. This systematic review summarizes the evidence on the assumed association between exogenous hormone use and OA. Medline was searched up to March 2008 for articles assessing associations between OA of hand, hip or knee and menopause-related aspects. Methodological quality of the studies was assessed systematically. The results were summarized in a best-evidence synthesis. Nineteen studies on exogenous hormone use are included. Limited evidence was seen for a protective effect of unopposed oestrogen use for incidence of hip replacement/joint replacement, and a protective trend for incident radiological OA (ROA) of the knee. In prevalence studies, conflicting evidence was observed for hormone replacement therapy (HRT) use with DIP ROA and 'any joint OA', and oestrogen use with clinical knee OA. We found limited evidence for a significantly increased risk by using HRT for clinical hip OA and a significant protective effect of long-term unopposed oestrogen use for hip ROA. For all other relations studied no associations were found. Heterogeneity between the hormones used and outcome measurements made statistical data pooling impossible. The assumed relationship between the exogenous hormone use and OA was not clearly observed in this review. The relationship is perhaps too complex, or other aspects, yet to be determined, play a role in the increased incidence in women aged over 50 yrs. However, there is some evidence of a protective effect of unopposed oestrogen use for hip OA.

Parasites of domestic and wild animals in South Africa. XVII. Arthropod parasites of Burchell's zebra, Equus burchelli, in the eastern Transvaal Lowveld.

Thirty-five Burchell's zebra, Equus burchelli, were shot for arthropod parasite recovery during the period November 1978-January 1982 in the Kruger National Park. Six species of gasterophilid larvae, 2 species of oestrid larvae, 2 louse species and 7 ixodid tick species were recovered. The distribution of the Gasterophilus spp. larvae within the gastrointestinal tract and their seasonal prevalence were determined. The seasonal prevalence of the oestrid larvae and 4 of the 7 ixodid tick species was also ascertained.

Helminth and arthropod parasites of vaal ribbok, Pelea capreolus, in the western Cape Province.

Five vaal ribbok, culled in the Bontebok National Park during December 1979, were examined for helminth and arthropod parasites. Ten nematode species, a louse and 2 tick species were recovered and there was also evidence of previous infestation by the larvae of 2 oestrid flies. The parasite burdens of the vaal ribbok are compared with those of sympatric bontebok and springbok culled at the same time.