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Hammond A, Buchynski K, Shynkaruk T, Crowe T, Schwean-Lardner K. Are turkey hens affected by light flicker? Effects on performance and health. Poult Sci 2024; 103:103747. [PMID: 38657524 PMCID: PMC11058885 DOI: 10.1016/j.psj.2024.103747] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/26/2024] Open
Abstract
Light flicker is a commonly overlooked factor of artificial light sources. This study aimed to determine the impacts of light-flicker frequency on performance, general health, and mortality of 11-wk Nicholas Select turkey hens. The experiment consisted of 2 trials (block) in a randomized complete block design, with 3 light-flicker frequency treatments (30, 90, or 195 Hz). Turkeys (n = 364 per replicate) were randomly placed into environmentally controlled rooms (3 room replicates per treatment per trial). Group body weight (BW) and feed consumption were measured at 0, 4, 8, and 11 wk, and feed efficiency (mortality corrected feed-to-gain; F:Gm) was calculated for each period. Mortality and culls were collected twice daily. Flock uniformity, feather condition and cleanliness, footpad score, and mobility were evaluated at 10 wk (30 birds per room). Litter quality and ocular weight and dimensions were evaluated (11 wk; 4 birds per room). Data were analyzed using Proc Mixed (SAS 9.4) and significance was declared when P < 0.05. At 8 wk, BW was lower under 30 Hz compared to 195 Hz (P = 0.03). Feed consumption was lowest under 30 Hz (0-4 wk and 4-8 wk; P < 0.01). Mortality-corrected F:G was improved under 30 Hz for 8 to 11 wk and 0 to 11 wk (P = 0.05 and P = 0.04, respectively). Total mortality was lower under 195 Hz compared to 30 Hz (P = 0.02). Uniformity, gait score, feather condition, and litter quality were unaffected by flicker. Footpad scores were improved under 90 Hz (P = 0.01), leading to an improved average footpad score (P = 0.02). Feather cleanliness was improved under 90 Hz compared to both 30 Hz and 195 Hz (P<0.01). Right eyeball dimensions differed across lighting treatments, with the dorso-ventral diameter being larger in birds under 30 Hz compared to 195 Hz (P = 0.05). The anterior-posterior size also increased in birds under 30 Hz compared to 90 Hz (P = 0.03). Light flicker impacted turkey hens, with the results demonstrating negative impacts on early growth and changes to ocular characteristics.
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Affiliation(s)
- A Hammond
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N5A8
| | - K Buchynski
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N5A8
| | - T Shynkaruk
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N5A8
| | - T Crowe
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N5A9
| | - K Schwean-Lardner
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada, S7N5A8.
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Hammond A, Buchynski K, Shynkaruk T, Brown J, Crowe T, Schwean-Lardner K. Do flickering lights impact turkey hen behavior, stress, and fear? Poult Sci 2024; 103:103699. [PMID: 38608391 PMCID: PMC11017336 DOI: 10.1016/j.psj.2024.103699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 03/25/2024] [Accepted: 03/26/2024] [Indexed: 04/14/2024] Open
Abstract
Little is known about the effect of light-flicker frequency on poultry, particularly on turkeys. This experiment examined the impact of light-flicker frequency on the behavior, stress, and fear response of Nicholas Select turkey hens reared to 11 wk. The experiment was a randomized complete block design (2 trials), with a one-way factorial analysis evaluating 3 light-flicker frequencies (30, 90, or 195 Hertz; Hz). Birds (n = 3,276 per trial) were housed in 9 individual environmentally controlled rooms (3 replicates per treatment per trial). Data collected included: behavior (4, 8, and 10 wk), incidence of aggressive damage, heterophil-to-lymphocyte ratio, and novel object test (daily d 1-7 and at 4, 8, and 11 wk). Data were analyzed using Proc Mixed (SAS 9.4), with significance declared at P ≤ 0.05. Behavior data are presented as the percentage of time spent performing the behavior. At 4 wk, gentle feather pecking and exploratory behaviors were higher under 195 Hz compared to 30 Hz (P = 0.04 and P = 0.05, respectively). Preening was higher under 90 Hz compared to 30 Hz (P = 0.05). At 8 wk, wing flapping was lowest under 195 Hz (P < 0.01). Gentle feather pecking was higher under 90 and 195 Hz compared to 30 Hz (P = 0.02). Fighting (P = 0.05), aggressive pecking (P = 0.02), and aggressive behaviors (P = 0.01) were lower under 30 Hz compared to 90 Hz. At 10 wk, preening was decreased under 30 Hz (P = 0.03). Incidences of aggressive damage were reduced under 30 Hz compared to 90 Hz (0 d-4 wk; P = 0.01) and under 30 compared to both 90 and 195 Hz (4-8 wk; P = 0.01). At 11 wk, heterophil-to-lymphocyte ratios were lowest under 30 Hz (P = 0.04). The novel object test was unaffected by flicker treatment. In conclusion, many behaviors and the stress and fear responses were unaffected by either visible or non-visible flicker. However, visible flicker (30 Hz) reduced some comfort and exploratory behaviors early in life, and the impact on preening continued to older ages, suggesting minor negative impacts of flicker, particularly early in life.
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Affiliation(s)
- A Hammond
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A8, Canada
| | - K Buchynski
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A8, Canada
| | - T Shynkaruk
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A8, Canada
| | - J Brown
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A8, Canada
| | - T Crowe
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A9, Canada
| | - K Schwean-Lardner
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, Saskatchewan S7N5A8, Canada.
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Duan E, Han G, Zhao S, Ma Y, Lv Y, Bai Z. Regulation of Meat Duck Activeness through Photoperiod Based on Deep Learning. Animals (Basel) 2023; 13:3520. [PMID: 38003138 PMCID: PMC10668642 DOI: 10.3390/ani13223520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 11/02/2023] [Accepted: 11/09/2023] [Indexed: 11/26/2023] Open
Abstract
The regulation of duck physiology and behavior through the photoperiod holds significant importance for enhancing poultry farming efficiency. To clarify the impact of the photoperiod on group-raised duck activeness and quantify duck activeness, this study proposes a method that employs a multi-object tracking model to calculate group-raised duck activeness. Then, duck farming experiments were designed with varying photoperiods as gradients to assess this impact. The constructed multi-object tracking model for group-raised ducks was based on YOLOv8. The C2f-Faster-EMA module, which combines C2f-Faster with the EMA attention mechanism, was used to improve the object recognition performance of YOLOv8. Furthermore, an analysis of the tracking performance of Bot-SORT, ByteTrack, and DeepSORT algorithms on small-sized duck targets was conducted. Building upon this foundation, the duck instances in the images were segmented to calculate the distance traveled by individual ducks, while the centroid of the duck mask was used in place of the mask regression box's center point. The single-frame average displacement of group-raised ducks was utilized as an intuitive indicator of their activeness. Farming experiments were conducted with varying photoperiods (24L:0D, 16L:8D, and 12L:12D), and the constructed model was used to calculate the activeness of group-raised ducks. The results demonstrated that the YOLOv8x-C2f-Faster-EMA model achieved an object recognition accuracy (mAP@50-95) of 97.9%. The improved YOLOv8 + Bot-SORT model achieved a multi-object tracking accuracy of 85.1%. When the photoperiod was set to 12L:12D, duck activeness was slightly lower than that of the commercial farming's 24L:0D lighting scheme, but duck performance was better. The methods and conclusions presented in this study can provide theoretical support for the welfare assessment of meat duck farming and photoperiod regulation strategies in farming.
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Affiliation(s)
- Enze Duan
- Agricultural Facilities and Equipment Research Institute, Jiangsu Academy of Agriculture Science, Nanjing 210014, China; (E.D.); (Y.M.)
- Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
| | - Guofeng Han
- Agricultural Facilities and Equipment Research Institute, Jiangsu Academy of Agriculture Science, Nanjing 210014, China; (E.D.); (Y.M.)
- Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
| | - Shida Zhao
- Agricultural Facilities and Equipment Research Institute, Jiangsu Academy of Agriculture Science, Nanjing 210014, China; (E.D.); (Y.M.)
- Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
| | - Yiheng Ma
- Agricultural Facilities and Equipment Research Institute, Jiangsu Academy of Agriculture Science, Nanjing 210014, China; (E.D.); (Y.M.)
- Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
| | - Yingchun Lv
- Agricultural Facilities and Equipment Research Institute, Jiangsu Academy of Agriculture Science, Nanjing 210014, China; (E.D.); (Y.M.)
- Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
| | - Zongchun Bai
- Agricultural Facilities and Equipment Research Institute, Jiangsu Academy of Agriculture Science, Nanjing 210014, China; (E.D.); (Y.M.)
- Key Laboratory of Protected Agriculture Engineering in the Middle and Lower Reaches of Yangtze River, Ministry of Agriculture and Rural Affairs, Nanjing 210014, China
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Dong Y, Fraley GS, Siegford JM, Zhu F, Erasmus MA. Comparing different environmental enrichments for improving the welfare and walking ability of male turkeys. PLoS One 2023; 18:e0285347. [PMID: 37159459 PMCID: PMC10168550 DOI: 10.1371/journal.pone.0285347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 04/20/2023] [Indexed: 05/11/2023] Open
Abstract
This study investigated age-related changes in turkey welfare measures (wounds, feather quality (FQ), feather cleanliness, and footpad condition (FCON)) and walking ability (gait) as influenced by different types of environmental enrichment (EE). Tom turkeys (n = 420) were randomly assigned to: straw bale (S), platform (P), platform + straw bale (PS), pecking block (B), tunnel (T) or control (C; no enrichment) group. Welfare measures and gait were assessed at 8, 12, 16 and 19 wk and analyzed using PROC LOGISTIC with Firth bias-correction. Better wing FQ with age was observed in turkeys in S and T groups. Turkeys in the S group had better wing FQ at 16 (P = 0.028) and 19 wk (P = 0.011) vs. 8 wk. Wing FQ (P = 0.008) was better at 19 vs. 8 wk for T turkeys. FCON worsened over time for turkeys in all treatment groups except for the S group. FCON was worse at 19 vs.8 wk for P (P = 0.024), PS (P = 0.039), B (P = 0.011), T (P = 0.004) and C (P = 0.014) turkeys and was worse at 19 vs. 12 wk for B (P = 0.038), T (P = 0.015) and C (P = 0.045) turkeys. FCON was worse at 19 vs. 16 wk for T (P = 0.007) and C (P = 0.048) turkeys. FCON was also worse at 16 vs. 8 wk for B (P = 0.046) turkeys. Gait worsened with increasing age in all treatment groups. Gait was worse at 19 wk for S (P < 0.001), P (P < 0.001), PS (P < 0.001) and B turkeys (P < 0.001) vs. earlier ages, while gait in T (P < 0.001) and C turkeys (P < 0.001) worsened starting at 16 wk.
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Affiliation(s)
- Yiru Dong
- Department of Animal Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Gregory S. Fraley
- Department of Animal Sciences, Purdue University, West Lafayette, IN, United States of America
| | - Janice M. Siegford
- Department of Animal Science, Michigan State University, East Lansing, MI, United States of America
| | - Fengqing Zhu
- Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, United States of America
| | - Marisa A. Erasmus
- Department of Animal Sciences, Purdue University, West Lafayette, IN, United States of America
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Jhetam S, Buchynski K, Shynkaruk T, Schwean-Lardner K. Evaluating the effects of stocking density on the behavior, health, and welfare of turkey hens to 11 weeks of age. Poult Sci 2022; 101:101956. [PMID: 35679672 PMCID: PMC9189194 DOI: 10.1016/j.psj.2022.101956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/26/2022] [Accepted: 04/30/2022] [Indexed: 11/25/2022] Open
Abstract
Nicholas Select hens (n = 3,550 poults in each of 2 experimental trials) were randomly placed in 1 of 4 stocking density (SD) treatments of 30, 40, 50, or 60 kg/m2 until 11 wk. Birds were housed in open rooms (67.5 m2) with 4 replications per treatment. Ventilation was adjusted in each room independently to ensure air quality measures did not differ across replicate rooms. At wk 8 and 11, footpad lesions, mobility, feather cover and cleanliness, behavior (recorded), and litter moisture were evaluated. Incidences of aggressive pecking were recorded daily. Heterophil/lymphocyte (H/L) ratios were evaluated at 3, 5, 8, and 11 wk. Data were analyzed using regression analyses in SAS 9.4 (Proc Reg and Proc RSReg; SD as independent variable). Differences were considered significant when P ≤ 0.05. Gait scores were not affected by SD. Average footpad scores worsened with increasing SD at wk 8 (linear) but were not affected at wk 11. Total feather cover scores and average feather cleanliness were poorer at high SD (linear) at wk 8 and 11. The incidence of aggressive pecking and culls for aggressive damage decreased linearly as SD increased. At 5 (linear) and 11 (quadratic) wk, H/L ratios increased as SD increased. At 8 wk, H/L ratios were highest in the 40 kg/m2 treatment (quadratic). At 8 wk, the percentage of birds at the feeder, resting, and total disturbances linearly increased as SD increased. The percentage of birds standing, walking, and litter pecking decreased linearly with increasing SD, while total aggressive behaviors (sum of fighting and aggressive pecking) decreased (quadratic). At 11 wk, the percentage of birds at the drinker, and decreased with increasing SD while resting, feather pecking, and severe disturbances increased as SD increased. Litter moisture increased linearly with increasing SD (wk 11). Turkey hen health and welfare were negatively impacted by higher SD. At low SD, there was notably more aggression which may also impact welfare.
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6
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Remonato Franco B, Leis ML, Wong M, Shynkaruk T, Crowe T, Fancher B, French N, Gillingham S, Schwean-Lardner K. Light Color and the Commercial Broiler: Effect on Ocular Health and Visual Acuity. Front Physiol 2022; 13:855266. [PMID: 35360232 PMCID: PMC8960735 DOI: 10.3389/fphys.2022.855266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Accepted: 02/16/2022] [Indexed: 01/04/2023] Open
Abstract
Light is a critical management factor for broiler production, and the wavelength spectrum, one of its components, can affect bird physiology, behavior and production. Among all the senses, sight is important to birds, and their visual system possess several adaptations that allow them to perceive light differently from humans. Therefore, it is critical to consider whether the exposure to monochromatic light colors influences broiler visual ability, which could affect behavioral expression. The present study examined the effects of various light colors on the visual systems of broiler chickens. Ross 708 males were raised from 0 to 35 days under three wavelength programs [blue (dominant wavelengths near 455 nm), green (dominant wavelengths near 510 nm) or white]. Broilers were given a complete ophthalmic examination, including chromatic pupillary light reflex testing, rebound tonometry, anterior segment biomicroscopy and indirect ophthalmoscopy (n = 36, day 21). To assess ocular anatomy, broilers were euthanized, eyes were weighed, and dimensions were taken (n = 108, day 16 and day 24). An autorefractor was used to assess the refractive index and the corneal curvature (n = 18, day 26). To evaluate spatial vision, broilers underwent a grating acuity test at one of three distances–50, 75, or 100 cm (n = 24, day 29). Data were analyzed as a one-way ANOVA using the MIXED procedure or Proc Par1way for non-normally distributed data. Significant differences were observed for refractive index and spatial vision. Birds raised under blue light were slightly more hyperopic, or far-sighted, than birds raised under white light (P = 0.01). As for spatial vision, birds raised under blue light took less time to approach the stimulus at distances of 50 cm (P = 0.03) and 75 cm (P = 0.0006) and had a higher success rate (choosing the right feeder, P = 0.03) at 100 cm than birds raised under white light. Improvements in spatial vision for birds exposed to blue light can partially explain the behavioral differences resulting from rearing broilers under different wavelengths.
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Affiliation(s)
- Bruna Remonato Franco
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada
| | - Marina L. Leis
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Melody Wong
- Department of Ophthalmology, Saskatoon City Hospital, University of Saskatchewan, Saskatoon, SK, Canada
| | - Tory Shynkaruk
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada
| | - Trever Crowe
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK, Canada
| | - Bryan Fancher
- Aviagen™ Inc., Cummings Research Park, Huntsville, AL, United States
| | - Nick French
- Aviagen™ Inc., Cummings Research Park, Huntsville, AL, United States
| | - Scot Gillingham
- Aviagen™ Inc., Cummings Research Park, Huntsville, AL, United States
| | - Karen Schwean-Lardner
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada
- *Correspondence: Karen Schwean-Lardner,
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Doornweerd JE, Kootstra G, Veerkamp RF, Ellen ED, van der Eijk JAJ, van de Straat T, Bouwman AC. Across-Species Pose Estimation in Poultry Based on Images Using Deep Learning. FRONTIERS IN ANIMAL SCIENCE 2021. [DOI: 10.3389/fanim.2021.791290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Animal pose-estimation networks enable automated estimation of key body points in images or videos. This enables animal breeders to collect pose information repeatedly on a large number of animals. However, the success of pose-estimation networks depends in part on the availability of data to learn the representation of key body points. Especially with animals, data collection is not always easy, and data annotation is laborious and time-consuming. The available data is therefore often limited, but data from other species might be useful, either by itself or in combination with the target species. In this study, the across-species performance of animal pose-estimation networks and the performance of an animal pose-estimation network trained on multi-species data (turkeys and broilers) were investigated. Broilers and turkeys were video recorded during a walkway test representative of the situation in practice. Two single-species and one multi-species model were trained by using DeepLabCut and tested on two single-species test sets. Overall, the within-species models outperformed the multi-species model, and the models applied across species, as shown by a lower raw pixel error, normalized pixel error, and higher percentage of keypoints remaining (PKR). The multi-species model had slightly higher errors with a lower PKR than the within-species models but had less than half the number of annotated frames available from each species. Compared to the single-species broiler model, the multi-species model achieved lower errors for the head, left foot, and right knee keypoints, although with a lower PKR. Across species, keypoint predictions resulted in high errors and low to moderate PKRs and are unlikely to be of direct use for pose and gait assessments. A multi-species model may reduce annotation needs without a large impact on performance for pose assessment, however, with the recommendation to only be used if the species are comparable. If a single-species model exists it could be used as a pre-trained model for training a new model, and possibly require a limited amount of new data. Future studies should investigate the accuracy needed for pose and gait assessments and estimate genetic parameters for the new phenotypes before pose-estimation networks can be applied in practice.
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Evaluation of Welfare in Commercial Turkey Flocks of Both Sexes Using the Transect Walk Method. Animals (Basel) 2021; 11:ani11113253. [PMID: 34827985 PMCID: PMC8614380 DOI: 10.3390/ani11113253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/29/2021] [Accepted: 11/11/2021] [Indexed: 11/17/2022] Open
Abstract
The study was conducted between March and September 2019 in six meat-type turkey flocks with similar management standard procedures using the transect walk method. The concept of the method is based on visual observation of the birds while slowly walking across the entire farm in predetermined transects. Each flock was evaluated at three different times during the fattening cycle: at 3 to 4, 12 to 13, and 19 to 20 weeks of age, and total number of males and females that were immobile or lame, had visible head, vent, or back wounds, were small, featherless, dirty, or sick, had pendulous crop, or showed aggression toward birds or humans were recorded. At each visit, NH3 and CO2 were measured within the facilities. In the first assessment, the most frequently observed welfare indicators were small size (0.87%) and immobility (0.08%). Males showed a significantly higher prevalence of small size (p < 0.01), sickness (p < 0.05), and dirtiness (p < 0.1) compared to females. In the second assessment, the most common findings in both sexes were dirtiness (1.65%) and poor feather condition (1.06%), followed by immobility (0.28%). Males were significantly dirtier (p < 0.001), had more immobile birds (p < 0.01) and birds with vent wounds (p < 0.1), but had fewer sick birds (p < 0.05). In the last assessment, an increase in immobile, lame, sick, and dead birds was recorded, indicating an increase in health problems. Higher CO2 (3000 and 4433 ppm) and NH3 (40 and 27.6 ppm) values were noted only at the first assessment in two facilities. Further analyses showed that slightly elevated NH3 and CO2 levels did not influence the occurrence of welfare indicators. This study is the first description of the welfare of commercial turkey flocks in Slovenia.
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Cui YM, Wang J, Zhang HJ, Qi GH, Wu SG. Effect of photoperiod on eggshell quality and quality characteristics of tibia, femur, and ulna in laying ducks. Poult Sci 2021; 100:101376. [PMID: 34391963 PMCID: PMC8371216 DOI: 10.1016/j.psj.2021.101376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 06/20/2021] [Accepted: 07/04/2021] [Indexed: 11/23/2022] Open
Abstract
We investigated the effect of photoperiod on eggshell quality, bone quality characteristics and bone metabolism related enzymes and factors in laying ducks. After adaption, 300 Jinding laying ducks (252-day-old) were randomly divided into 5 treatments, receiving 12L (hours of light):12D (hours of darkness), 14L:10D, 16L:8D, 18L:6D or 20L:4D, respectively. Each group had 6 replicates of 10 birds each. The feeding experiment lasted 8 wk. Compared with 12L:12D, the higher values of eggshell breaking strength occurred in ≥18 h photoperiods at the end of 6 wk, and in ≥16 h photoperiods at the end of 4 wk, with the common highest values in 18 h photoperiod (P ˂ 0.05). Besides, 18L:6D had higher values of ultimate load Fu and cortical cross-sectional area A in tibia, femur, and ulna (P ˂ 0.05), compared with 12L:12D. The higher values of proximal bone mineral content (BMC; tibia), distal BMC (ulna), total Ca (tibia), and cortical volumetric bone mineral density (vBMC; tibia and ulna) were observed in 16L:8D and 18L:6D treatments (P ˂ 0.05). Meanwhile, 18 h photoperiod group had the higher proximal BMC (femur) and total Ca in ulna (P ˂ 0.05). In serum, compared with 12L:12D group, the higher ALP activity occurred in ≥16 h photoperiods (0:00 and 18:00), with the highest values in 18L:6D treatment (P ˂ 0.05); the higher values of TGF-β (6:00) and OC (6:00 and 18:00) were simultaneously observed in 18 h photoperiod (P ˂ 0.05). Moreover, values of trACP activity, TNF-α and IL-6 contents decreased in ≥18 h photoperiods at 0:00 (P ˂ 0.05), compared with 12L:12D group. To sum up, an appropriate photoperiod could improve eggshell quality, bone strength and mineral content through increasing osteogenesis during the light time and decreasing resorption activity during the dark, and 18 h is an adequate photoperiod for the eggshell and bone quality of laying ducks.
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Affiliation(s)
- Yao-Ming Cui
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China; College of Biological Engineering, Henan University of Technology, No. 100 Lianhua Street, Zhengzhou, Henan Province 450001, China
| | - Jing Wang
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Hai-Jun Zhang
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Guang-Hai Qi
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Shu-Geng Wu
- Laboratory of Quality & Safety Risk Assessment for Animal Products on Feed Hazards (Beijing) of the Ministry of Agriculture and Rural Affairs Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
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Vasdal G, Marchewka J, Moe RO. Associations between animal-based measures at 11 wk and slaughter data at 20 wk in turkey toms (Meleagris gallopavo). Poult Sci 2020; 100:412-419. [PMID: 33518092 PMCID: PMC7858081 DOI: 10.1016/j.psj.2020.11.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 10/30/2020] [Accepted: 11/09/2020] [Indexed: 11/27/2022] Open
Abstract
To monitor animal welfare on a commercial scale, systematic collection and evaluation of slaughterhouse data is the most feasible method. However, we need to know whether slaughterhouse data retrospectively and reliably reflect information about the birds' welfare on-farm. The aim of this study was therefore to investigate associations between animal-based welfare measures in flocks of turkey toms at 11 wk of age recorded with the transect walk and slaughter data at 20 wk of age. A total of 20 commercial flocks of turkey toms were visited, where an observer walked the transects in a random order and recorded the total number of birds per transect that were immobile, lame, with visible head, tail, or wing wounds, small, featherless, dirty, sick, terminal, or dead. Slaughterhouse data were provided for each flock. Univariate and multivariate linear regression models were used to investigate the associations between on-farm and slaughterhouse measures. Increased prevalence of immobile toms at week 11 resulted in more birds rejected at slaughter owing to leg issues (P = 0.02) and airsacculitis (P < 0.001). More lame birds on-farm were associated with an overall higher rejection rate at slaughter (P < 0.001). Flocks with more featherless birds had significantly more birds being rejected at slaughter owing to skin issues (P = 0.02). More dirty birds at week 11 resulted in more birds being rejected owing to airsacculitis at slaughter (P < 0.001). A higher mortality on-farm was associated with more birds rejected for being too small (P = 0.04). In conclusion, significant associations between animal-based measures of turkey toms as assessed by the transect walk method on-farm at 11 wk and slaughter data at 20 wk were identified.
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Affiliation(s)
- Guro Vasdal
- Animalia, Norwegian Meat and Poultry Research Centre 0515, Oslo, Norway
| | - Joanna Marchewka
- Institute of Genetics and Animal Biotechnology, Polish Academy of Sciences 05-552, Magdalenka, Poland.
| | - Randi O Moe
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine 0033, Oslo, Norway
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11
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Marchewka J, Vasdal G, Moe RO. Identifying welfare issues in turkey hen and tom flocks applying the transect walk method. Poult Sci 2019; 98:3391-3399. [PMID: 31064008 DOI: 10.3382/ps/pez211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/23/2019] [Indexed: 11/20/2022] Open
Abstract
In commercial conditions turkey tom and hen flocks are reared under similar housing and management conditions. However, the 2 sexes differ with regard to behavioral and physiological characteristics, and are slaughtered at different ages, resulting in different growth patterns. The rearing environment and management likely have similar effects on the welfare of both sexes reared in 1 barn, as usual in commercial flocks, but this has not previously been studied. The main aim of current study was to identify on-farm health and welfare issues of commercially reared hen and tom turkeys at 11 wk of age using the transect walk method. The study was conducted between November 2017 and March 2018 in 20 commercial turkey flocks on 16 different farms in the eastern part of Norway. On each farm, 1 barn, divided into tom and hen area, was evaluated using transect walk method. An observer walked the transects in random order and recorded the total number of birds per transect that were immobile; lame, with visible head, tail, or wing wounds; small; featherless; dirty; sick; terminal or dead. To analyze the data, we applied ANOVA and Spearman correlations in SAS software (v 9.3). The most commonly observed welfare indicators across sexes were dirty and featherless birds, and birds with tail and wing wounds. Across sexes, poor litter quality resulted in more head wounds (P < 0.05). Toms had significantly more tail wounds (P < 0.001), there were more sick birds (P < 0.01) and more terminal birds (P < 0.01) compared to hens at the same age. Several of the welfare indicators were positively correlated between the sexes, including lame, head, wing- and tail-wounded, dirty, and dead birds, suggesting similar underlying environmental causes affecting animal welfare.
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Affiliation(s)
- Joanna Marchewka
- Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzebiec, 05-552 Magdalenka, Poland
| | - Guro Vasdal
- Norwegian Meat and Poultry Research Centre, Lorenveien 38, 0515 Oslo, Norway
| | - Randi O Moe
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, PO Box 8146 dep., 0033 Oslo, Norway
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12
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Shynkaruk T, Classen HL, Crowe TG, Schwean-Lardner K. The impact of dark exposure on broiler feeding behavior and weight of gastrointestinal tract segments and contents. Poult Sci 2019; 98:2448-2458. [PMID: 30690551 DOI: 10.3382/ps/pez018] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/07/2019] [Indexed: 01/09/2023] Open
Abstract
Ross 308 broilers were observed at 2 ages to quantify how duration of darkness affects behavior and alters the gastrointestinal tract (GIT, segment and content weights) over 24 h. Four treatments provided 1 (1D), 4 (4D), 7 (7D), or 10 (10D) h of darkness. Birds (n = 4000) were housed in 8 rooms with 8 pens per room (2 replications per treatment and 4 replications per gender per room). The GIT data were collected on day 27 to 28 (6 males per treatment, euthanized at 2 h intervals for 24 h) and expressed as a percentage of body weight. Data were analyzed as a completely randomized design, with treatment nested within room. Production data were analyzed as a 4 (dark) x 2 (gender) factorial arrangement and GIT data as a 4 (dark) x 12 (time) factorial arrangement. Regression analyses established relationships between darkness and dependent variables. At 31 d, regression analyses showed no effect on body weight. The highest feed consumption was observed under 4D. Mortality was lowest under 10D. Birds on 10D were the most feed efficient and had the heaviest crops. Crop content interacted with time of day, with peaks prior to dark under 4D, 7D, and 10D. Empty gizzard weight increased linearly as dark increased (P < .01). Behavior was examined as a 4 (dark) x 2 (age) x 2 (gender) factorial arrangement of treatments. Five birds per gender per room were focally observed for 24 h. Dark data were examined using regression analyses and an analysis of variance assessed age and gender data. As dark increased, feeding bout frequency increased and total time spent at the feeder decreased linearly (P = 0.01 and P < .01, respectively). As birds aged, feeding frequency decreased and feed bout length increased. Males visited the feeder more frequently. Birds anticipated dark periods >4 h and increased feeding activity prior to dark. Broilers adapt their feeding behavior in response to dark exposure, which alters GIT segment and content weight and likely feed passage rate.
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Affiliation(s)
- T Shynkaruk
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon S7N 5A8, Canada
| | - H L Classen
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon S7N 5A8, Canada
| | - T G Crowe
- Department of Mechanical Engineering, University of Saskatchewan, Saskatoon 57N 5A9, Canada
| | - K Schwean-Lardner
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon S7N 5A8, Canada
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Roehrig C, Torrey S. Mortality and Early Feeding Behavior of Female Turkey Poults During the First Week of Life. Front Vet Sci 2019; 6:129. [PMID: 31106215 PMCID: PMC6494925 DOI: 10.3389/fvets.2019.00129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/08/2019] [Indexed: 11/25/2022] Open
Abstract
Turkey poults are susceptible to early mortality and poor initial feeding behavior for reasons that are not well-understood. This study was conducted to investigate the relationship between the development of turkey poult feeding behavior and early mortality, with a focus on the effect of biological age and diet. We hypothesized that increasing biological age would increase mortality, and that poults that had earlier feeding behavior would have decreased mortality. Nine hundred and sixty female turkey poults were randomly assigned to 24 pens (40 poults per pen). The study was conducted as a completely randomized block design with a factorial arrangement of two ages (early and standard hatch) and three diets (control, modified A, and modified Ca/P B, differing primarily in the Ca/P ratio and percent fines). The behavior during the first 24 h after placement of newly placed poults was examined. Growth performance and mortality throughout the first week of life was also measured to determine if early behavior had any impact on these variables over time. Behavior during the first 24 h was similar between the age treatments; both spent ~2.5% of the time drinking, 7% of the time feeding, 12% of the time active and 80% of the time inactive/resting. There was no effect of diet or age treatment on latency to feed or drink. Growth variables were not affected by biological age. However, there was a significant diet and biological age effect on bodyweight and mortality. Standard hatch poults fed a control diet were lighter than other poults at 7 d, while standard hatch poults fed the diet with the lowest Ca:P had the highest mortality. For all treatments, early mortality was primarily due to yolk sac infection, although >1% of placed poults died due to starvation. Findings of the present study indicate that, regardless of biological age or diet, poults established feeding behavior within the first 24 h and the majority of early poult mortality under these experimental conditions was due to factors other than starvation.
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Affiliation(s)
- Colleen Roehrig
- Campbell Centre for the Study of Animal Welfare, University of Guelph, Guelph, ON, Canada
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
| | - Stephanie Torrey
- Campbell Centre for the Study of Animal Welfare, University of Guelph, Guelph, ON, Canada
- Department of Animal Biosciences, University of Guelph, Guelph, ON, Canada
- *Correspondence: Stephanie Torrey
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14
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Cui YM, Wang J, Zhang HJ, Feng J, Wu SG, Qi GH. Effect of photoperiod on growth performance and quality characteristics of tibia and femur in layer ducks during the pullet phase. Poult Sci 2019; 98:1190-1201. [DOI: 10.3382/ps/pey496] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 11/01/2018] [Indexed: 01/14/2023] Open
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15
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Beaulac K, Schwean-Lardner K. Assessing the Effects of Stocking Density on Turkey Tom Health and Welfare to 16 Weeks of Age. Front Vet Sci 2018; 5:213. [PMID: 30234138 PMCID: PMC6131652 DOI: 10.3389/fvets.2018.00213] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/15/2018] [Indexed: 11/29/2022] Open
Abstract
Four levels of turkey tom stocking density (SD) (30, 40, 50, 60 kg/m2) were evaluated in two 16 week trials (n = 2,868 Nicholas Select). Poults were allocated to one of eight independently ventilated rooms per trial (6.71 × 10.06 m) based on final predicted body weight (two replicates per SD per trial). Room temperature, humidity, carbon dioxide and ammonia concentration were recorded throughout the trial; ventilation was adjusted to equalize air quality across treatments. Mobility (gait score, scale 0-5) was recorded at 12 and 16 weeks (20 birds per replicate). Footpad lesion score (scale 0-4), feather condition (scale 1-4), and cleanliness scores (scale 1-4) were recorded at 10 (Trial 2), 12, and 16 weeks of age (20 birds per replicate). Aggressive injury incidence was recorded daily for Trial 2. Stress (heterophil/lymphocyte ratio) was evaluated at 4, 12, and 16 weeks of age (15 birds per replicate). Behavior was recorded and scan sampled (field of view) at 12 (Trial 1), 14, and 16 weeks. Data were analyzed using regression analysis (linear, Proc Reg; quadratic, Proc RSReg) for relationships between the variables and SD. Differences were considered significant when p ≤ 0.05. Mobility and footpad lesions were negatively affected by increasing SD (linear) at 16 weeks only. Feather condition and cleanliness decreased linearly as SD increased at week 10, 12, and 16. The incidence of aggressive damage was higher as SD increased during week 4-8 (quadratic). Heterophil/lymphocyte ratios increased linearly at 4 weeks (similar trend at 12 weeks). Behavior was impacted at 12 weeks of age with standing behavior showing a quadratic response, and walking and total disturbance showing a linear decrease as SD increased. Resting, preening, and comfort behaviors increased linearly (14 weeks), while walking and strutting decreased linearly with increasing SD. Finally, at 16 weeks of age resting, standing, walking, feeding, and total disturbance responded quadratically while preening behavior increased linearly with increasing SD. Results suggest that increasing SD negatively impacts bird health and wellbeing through decreased mobility, increased footpad lesions, poorer feather condition and cleanliness, and behavioral changes, but that very low SD (30 kg/m2) may result in increased aggressive damage.
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Affiliation(s)
| | - Karen Schwean-Lardner
- Department of Animal and Poultry Science, University of Saskatchewan, Saskatoon, SK, Canada
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16
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Bartels T, Lütgeharm JH, Wähner M, Berk J. UV reflection properties of plumage and skin of domesticated turkeys (Meleagris gallopavo f. dom.) as revealed by UV photography. Poult Sci 2017; 96:4134-4139. [PMID: 29053857 DOI: 10.3382/ps/pex256] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 08/24/2017] [Indexed: 11/20/2022] Open
Abstract
Reflection and fluorescence properties of feathered and non-feathered body regions of white- and bronze-colored fattening turkeys of various ages were examined by ultraviolet (UV) photography. The examinations were carried out on 20 white-feathered fattening turkeys (B.U.T. 6; 10 males, 10 females) and 20 bronze-feathered fattening turkeys (Grelier 708; 10 males, 10 females) over a period of 21 weeks. The turkeys were photographed once a wk under long-wave UV (UVA) radiation illumination (λ = 344-407 nm) using a digital camera. A bandpass filter was used for UV reflectography to filter out the visible components of the used light source. A longpass filter was used for UV fluorescence photography to avoid blurring in the image due to chromatic aberration as a result of UV illumination. We found that natal down feathers of white-feathered turkeys showed an intense yellowish-green fluorescence under UVA light. UVA fluorescence also was shown by the natal downs of the slightly melanized plumage areas of bronze turkeys. Vaned feathers of white fattening turkeys reflected UVA radiation. Freshly molted feathers were optically distinguishable from the previous feather generation due to their more intense UVA reflection. In bronze turkeys, both the bright end seams of the dark pennaceous feathers and rectrices and the bright banding of primary and secondary remiges reflected UVA radiation. Intense UVA fluorescence was recognizable in day-old chicks of both color variants on the scutellate scales of the legs and toes. In male turkeys of both color variants, UVA-reflecting parts were recognizable with increasing age on the featherless head region. The UVA-fluorescent and UVA-reflective characteristics of the plumage of fattening turkeys were closely related to the plumage color, the feather type, the molting state, and the age of the birds. Further research is needed regarding the UVA-reflecting properties of the turkey plumage and the effects of full-spectrum illumination, including the UVA spectrum, on the behavior and health of fattening turkeys.
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Affiliation(s)
- T Bartels
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Institute for Animal Welfare and Animal Husbandry, Celle, Germany
| | - J-H Lütgeharm
- Anhalt University of Applied Sciences, Department of Agriculture, Ecotrophology and Landscape Development, Bernburg, Germany
| | - M Wähner
- Anhalt University of Applied Sciences, Department of Agriculture, Ecotrophology and Landscape Development, Bernburg, Germany
| | - J Berk
- Federal Research Institute for Animal Health, Friedrich-Loeffler-Institut, Institute for Animal Welfare and Animal Husbandry, Celle, Germany
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Veldkamp T, Hocking PM, Vinco LJ. Effect of crude protein concentration and dietary electrolyte balance on litter quality, foot pad dermatitis, growth performance and processing yields in two medium heavy turkey hybrids. Br Poult Sci 2017; 58:557-568. [PMID: 28675310 DOI: 10.1080/00071668.2017.1349296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
1. An experiment was conducted to investigate the effect of crude protein (CP) concentration and dietary electrolyte balance (DEB) on growth performance, processing yields, litter quality and foot pad dermatitis (FPD) in male turkeys from two commercial hybrids. Soya bean meal was replaced by vegetable protein sources selected for lower K concentrations to lower DEB in order to improve litter quality and subsequent quality of foot pads. 2. Effects of CP on litter friability and wetness were not consistent during the production period. FPD in turkeys fed on diets with low CP was significantly lower than FPD in turkeys fed on diets with high CP until 84 d. Growth performance was adversely affected at low CP. Processing yields were not affected by CP. 3. Litter was significantly dryer in pens of turkeys fed on diets with low DEB than in pens of turkeys fed on diets with high DEB. FPD in turkeys fed on diets with low DEB was significantly lower than in turkeys fed on diets with high DEB. Growth performance and processing yields were adversely affected at low DEB. 4. FPD in turkey hybrid A was higher than in turkey hybrid B at 28 d of age. Thereafter, no differences in FPD between turkey hybrids were observed. Growth performance and processing yields were not affected by turkey hybrid. 5. Overall, a significant interaction effect of CP × DEB was observed for FCR: in turkeys fed on the high DEB treatment, FCR of turkeys fed on the high CP diets was lower than FCR of turkeys fed on the low CP (LCP) diets whereas on the low DEB treatment, FCR was not affected by CP treatment. 6. It was concluded that litter quality can be improved and FPD may be decreased in turkeys fed on diets containing lower CP and DEB levels.
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Affiliation(s)
- T Veldkamp
- a Wageningen Livestock Research , Wageningen , The Netherlands
| | - P M Hocking
- b The Roslin Institute and Royal (Dick) School of Veterinary Studies , University of Edinburgh , Midlothian , UK
| | - L J Vinco
- c National Reference Centre for Animal Welfare , Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna , Brescia , Italy
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18
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Leis ML, Dodd MMU, Starrak G, Vermette CJ, Gomis S, Bauer BS, Sandmeyer LS, Schwean-Lardner K, Classen HL, Grahn BH. Effect of prolonged photoperiod on ocular tissues of domestic turkeys. Vet Ophthalmol 2016; 20:232-241. [PMID: 27302599 DOI: 10.1111/vop.12395] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE The objective of this study is to investigate the structural and functional ocular changes that develop in turkeys exposed to a photoperiod of 23 h of light (23L) compared with a photoperiod of 14 h of light (14L). PROCEDURES Ten-day-old Nicholas heavy strain poults were exposed to either a 14L or 23L photoperiod. Between 16 and 18 weeks of age, equal numbers of turkeys per treatment group underwent ophthalmic examination (biomicroscopy, indirect ophthalmoscopy) (n = 14), refractometry (n = 20), keratometry (n = 20), tonometry (n = 20), and full-field electroretinography (ERG) (n = 14). Postmortem analyses included orbital magnetic resonance imaging (MRI) (n = 10) and light microscopy (n = 24) at 18 weeks of age. RESULTS Autorefraction revealed a median of -0.13 for sphere in both groups (P = 0.69), which is approximately emmetropia. The radius of curvature of the cornea was significantly higher (P = 0.0001) and the refractive power of the cornea was significantly lower (P = 0.0001) in the 23L group. The astigmatic power was significantly greater in the 23L group (P = 0.0001). Mean intraocular pressure did not differ between groups (P = 0.085). Turkeys from the 23L group had significantly larger globes in nasotemporal (P = 0.0007), dorsoventral (P = 0.015), and anterioposterior (P = 0.021) directions, and anterior chambers were more shallow (P = 0.0002). ERGs revealed the 23L group to have lower a- and b-wave amplitudes and significantly lower cone flicker amplitudes (P = 0.0008). Light microscopic examination revealed 23L turkeys to have significantly decreased numbers of nuclei in the outer nuclear layer (P = 0.0001) and inner nuclear layer (P = 0.0186), and decreased choroidal thickness (P = 0.0008). The prevalence of cataract in the 23L group was significantly higher (P = 0.001). CONCLUSIONS Exposing turkeys to a prolonged photoperiod induces significant ocular disease.
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Affiliation(s)
- Marina L Leis
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | | | - Gregory Starrak
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Catherine J Vermette
- College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Susantha Gomis
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Bianca S Bauer
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Lynne S Sandmeyer
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Karen Schwean-Lardner
- College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Henry L Classen
- College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, Canada
| | - Bruce H Grahn
- Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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