Canadian Journal of Animal Science最新文献

{"title":"Potential of eight mutations for marker-assisted breeding in Chinese Lulai black pigs","authors":"Jing Xu, Aimei Jiang, Changzheng Zhang, Yangqing Zheng, Tingrong Zhang, Lisheng Zhou","doi":"10.1139/cjas-2021-0108","DOIUrl":"https://doi.org/10.1139/cjas-2021-0108","url":null,"abstract":"Abstract Molecular marker-assisted selection (MAS) provides an efficient tool for pig breeding. In this study, according to the literature, we selected eight effective or causal mutations from eight functional genes, including five causal mutations in PHKG1 (rs330928088), MUC13 (rs319699771), IGF2 (g.3072 G>A), VRTN (g.20311_20312ins291), and MYH3 (XM_013981330.2:g.-1805_-1810del) genes, and three effective mutations in LIPE (rs328830166), LEPR (rs45435518), and MC4R (rs81219178) genes, to investigate their potential breeding effect in 418 Lulai pigs. The linear model was used to analyse the association between mutations and intramuscular fat (IMF) content, average backfat thickness, and muscle moisture %. The results revealed that amongst the three effective mutations, only the mutation in the LEPR gene, which affects IMF deposition, was significantly associated with IMF content. However, the other molecular markers were not significantly associated with the affected traits reported in previous studies, and these mutations are ineffective for MAS in the Lulai black pig population. Therefore, causal mutations in PHKG1, IGF2, and VRTN genes, and an effective mutation in LEPR gene could be used as effective breeding makers for MAS in Lulai pigs. These results can provide helpful information for further breeding in Lulai black pigs. Résumé La sélection assistée par marqueur moléculaire (MAS — « molecular marker-assisted selection ») offre un outil efficace pour la reproduction des porcs. Dans cette étude, selon la littérature, nous avons choisi huit mutations efficaces et causales provenant de huit gènes fonctionnels, incluant cinq mutations causales dans les gènes PHKG1 (rs330928088), MUC13 (rs319699771), IGF2 (g.3072G>A), VRTN (g.20311_20312ins291) et MYH3 (XM_013981330.2:g.-1805_-1810del), et trois mutations efficaces dans les gènes LIPE (rs328830166), LEPR (rs45435518) et MC4R (rs81219178), afin d’étudier les effets potentiels de celles-ci sur la reproduction de 418 porcs Lulai. Le modèle linéaire a été utilisé pour analyser l’association entre les mutations et la teneur en gras intramusculaire (IMF — « intramuscular fat »), l’épaisseur moyenne du gras dorsal (ABT — « average backfat thickness »), et le pourcentage d’humidité dans le muscle (MMP — « muscle moisture percent »). Les résultats ont révélé que parmi les trois mutations efficaces, seule la mutation dans le gène LEPR, qui a un effet sur le dépôt d’IMF, était associée de façon significative à la teneur en IMF. Par contre, les autres marqueurs moléculaires n’étaient pas associés de façon significative avec les caractéristiques affectées rapportées dans les études préalables, et ces mutations sont non efficaces pour la MAS dans la population de porcs noirs Lulai. Donc, les mutations causales dans les gènes PHKG1, IGF2 et VRTN, et une mutation efficace dans le gène LEPR pourraient être utilisées comme marqueurs efficaces de reproduction pour la MAS chez les porcs Lulai. Ces résultats pourr","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":"102 1","pages":"431 - 439"},"PeriodicalIF":1.0,"publicationDate":"2022-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41986363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficacy of three heat-stable microbial phytases on growth performance and bone development and strength of broilers fed diets deficient in available phosphorus","authors":"H. Solomon, F. A. Adejoro, T. Nkukwana","doi":"10.1139/cjas-2020-0188","DOIUrl":"https://doi.org/10.1139/cjas-2020-0188","url":null,"abstract":"Abstract A total of 2340 as-hatched Cobb500 chicks were allocated to 9 treatments, each with 13 replicate pens to evaluate the effects of either three phytase enzymes in a P-deficient diet. Starter and finisher diets consisted of a positive control (PC) and negative control 1 and 2 (NC1 and NC2, respectively). The PC, NC1, and NC2 diets had Ca:avP (available phosphorus) ratios of 0.50, 0.33, and 0.43 in the starter feed, and 0.46, 0.22, and 0.35 in the finisher feed, respectively; NC1 diets were then supplemented with Phytaverse, Quantum Blue, and Axtra-PHY at 500 and 1000 FTU/kg. Enzyme type had significant effects on body weight gain, feed conversion ratio, and production efficiency factor during the 0–7-day period. Interactions between enzyme type and inclusion levels had a significant effect on feed intake (FI) at 1–21-day (P = 0.02) and 1–35-day (P = 0.031) age. While FI decreased as Axtra-PHY inclusion levels increased from 500 to 1000 FTU/kg feed, FI increased in birds supplemented with Quantum Blue, but with no effects on Phytaverse-supplemented birds. Increasing the enzyme dose to 1000 FTU/kg feed improved bone-breaking strength but did not affect growth performance, tibia ash, Ca, or P concentration of the birds. Résumé Un total de 2340 poussins Cobb500 éclos ont été alloués à neuf traitements, chacun avec 13 enclos répliqués pour évaluer la réponse des poulets à griller à trois enzymes phytases dans une diète déficiente en P. Les diètes de démarrage et de finition consistaient d’un témoin positif (PC — « positive control »), et témoins négatifs 1 et 2 (NC — « negative control »; NC1, NC2). Les diètes PC, NC1 et NC2 avaient des rapports Ca:P disponible (Ca:avP — « calcium:available P ») de 0,50, 0,33 et 0,43 dans la diète de démarrage; et 0,46, 0,22, 0,35 dans la diète de finition; les diètes NC1 étaient alors supplémentées de Phytaverse, Quantum Blue et Axtra-PHY à raison de 500 et 1000 FTU/kg. Le type d’enzyme a eu un effet significatif sur le gain de poids corporel, le taux de conversion alimentaire (FCR — « feed conversion ratio ») et le facteur d’efficacité de production (PEF — « production efficiency factor ») durant la période de 0 à 7 jours. Les interactions entre le type d’enzyme et les niveaux d’inclusion avaient des effets significatifs sur la consommation (FI — « feed intake ») aux jours 1 à 21 (P = 0,02) et jours 1 à 35 (P = 0,031) d’âge. Tandis que le FI diminuait avec l’augmentation des niveaux d’inclusion d’Axtra-PHY de 500 à 1000 FTU/kg d’aliments, le FI a augmenté chez les poulets ayant reçu des suppléments de Quantum Blue, et il n’y a pas eu d’effet chez les poulets ayant reçu les suppléments de Phytaverse. Augmenter la dose d’enzyme à 1000 FTU/kg d’aliments a amélioré la résistance aux fractures, mais n’a pas eu d’effet sur la performance de croissance, ni les cendres du tibia, ni les concentrations de Ca ou P des poulets. [Traduit par la Rédaction]","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":"102 1","pages":"420 - 430"},"PeriodicalIF":1.0,"publicationDate":"2022-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47781918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First-service pregnancy rate among beef heifers with different residual feed intake","authors":"A. Behrouzi, M. Colazo, Changxi Li, C. Fitzsimmons","doi":"10.1139/cjas-2021-0105","DOIUrl":"https://doi.org/10.1139/cjas-2021-0105","url":null,"abstract":"The effect of residual feed intake (a measure of feed efficiency) adjusted for backfat thickness (RFIfat) on pregnancy rate (PR) was examined in Angus heifers over 2 yr. High- or Low-RFI heifers were timed artificially inseminated (TAI) with semen from High- or Low-RFI sires, respectively. There was a negative association (P < 0.05) between RFIfat value and PR in Year II for Low-RFI heifers. In Year I, the interaction between RFIfat and AI sires was significant in High-RFI heifers (P < 0.05) and tended to differ in Low-RFI heifers (P < 0.1). Therefore, selecting for feed efficiency may have negative consequences on fertility.","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43987676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative digestibility of energy, dry matter, and nutrients by gestating and lactating sows fed corn–soybean meal diets without or with full-fat or defatted rice bran","authors":"G. Casas, M. Oliveira, C. Espinosa, H. Stein","doi":"10.1139/cjas-2021-0086","DOIUrl":"https://doi.org/10.1139/cjas-2021-0086","url":null,"abstract":"Twenty-four gestating sows and 24 lactating sows were randomly allotted to three diets with eight replicate sows per treatment in a 3 × 2 factorial arrangement. Different sows were used in gestation and lactation periods. The hypothesis was that digestibility of gross energy (GE), dry matter (DM), and nutrients in lactating sows is not different from that in gestating sows. A corn–soybean-meal diet and two full-fat-rice-bran or defatted rice bran diets were used. Results indicated that regardless of diet, lactating sows had greater (P < 0.01) apparent total tract digestibility of GE, DM, neutral detergent fiber, organic matter, and phosphorus than gestating sows.","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44284567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Using publicly available weather station data to investigate the effects of heat stress on milk production traits in Canadian Holstein cattle","authors":"I. Campos, T. Chud, Hinayah Rojas de Oliveira, C. Baes, Á. Cánovas, F. Schenkel","doi":"10.1139/cjas-2021-0088","DOIUrl":"https://doi.org/10.1139/cjas-2021-0088","url":null,"abstract":"Heat stress imposes a challenge to the dairy industry, even in northern latitudes. In this study, publicly available weather station data was combined with test-day records for milk, fat, and protein yields to identify the temperature-humidity index (THI) thresholds at which heat load starts affecting milk production traits in Canadian Holstein cows. Production loss per THI unit above the threshold for each trait was estimated. Test-day records from 2010-2019 from 166,749 cows raised in Ontario and from 221,214 cows raised in Quebec were analyzed. Annual economic losses due to heat stress were estimated from the average losses of fat and protein yields based on the annual average of 156 days with THI exceeding the calculated thresholds. Average thresholds for the daily maximum (THI_max) and daily average (THI_avg) THI estimated across lactations in both provinces were THI_max (THI_avg) 68 (64), 57 (50), and 60 (58) for milk, fat, and protein yield, respectively, indicating that milk components are more sensitive to heat stress. An economic loss of about $34.5 million per year was estimated. Our findings contribute to an initial investigation into the impact of heat stress on the Canadian dairy industry and provides a basis for genetic studies on heat tolerance.","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47061674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship between udder skin surface temperature and milk production and composition in dairy cattle (Bos taurus Linnaeus, 1758)","authors":"D. Zaborski, Maria Soroko-Dubrovina, W. Grzesiak, M. Parafiniuk, A. Modrzejewski, Oleh Klym, O. Stadnytska, J. Wójcik","doi":"10.1139/cjas-2021-0092","DOIUrl":"https://doi.org/10.1139/cjas-2021-0092","url":null,"abstract":"Abstract The aim of the present study was to determine correlations between udder skin surface temperatures and milk yield and estimated composition in dairy cows. The thermographic images of 34 Polish Holstein–Friesian black-and-white cows were taken in a milking parlor before and after milking. Partial correlation coefficients were calculated between the surface temperatures of the udder hind quarters and milk production traits controlling for age, parity, year, and milking time. Daily milk yield was weakly and nonsignificantly correlated with surface temperatures (rp ranging from −0.19 to 0.21), except for the mean and maximum temperatures of the left hind quarter after milking (rp = 0.40 and rp = 0.38, respectively). There were significant correlations of skin surface temperature with estimated fat content (rp = −0.55 to 0.48), protein content (rp = −0.39 to 0.42), fat yield (rp = −0.42 to 0.54), and protein yield (rp = 0.37 to 0.54). The estimated somatic cell count was significantly correlated with the minimum temperature (rp = −0.54 to −0.36). The estimated urea content was significantly correlated with the minimum temperature (rp = 0.52). A larger sample size is required in future research to confirm these preliminary results. Résumé Le but de la présente étude était de déterminer les corrélations entre les températures de surface de la peau du pis et le rendement et la composition estimés du lait chez les vaches laitières. Les images thermographiques de 34 vaches Holstein–Friesian black-and-white polonaises ont été prises dans une salle de traite avant et après la traite. Les coefficients de corrélation partielle ont été calculés entre la température de surface du pis de l’arrière-train et les caractéristiques de production de lait, en contrôlant pour l’âge, la parité, l’année et l’heure de traite. Il y avait une corrélation faible et non significative entre le rendement quotidien de lait et les températures de surface (rp allant de –0,19 à 0,21), sauf pour la température moyenne et maximale de l’arrière-train gauche après la traite (rp = 0,40 et rp = 0,38, respectivement). Il y avait des corrélations significatives entre la température de surface de la peau avec la teneur estimée en gras (rp = –0,55 à 0,48), la teneur en protéines (rp = –0,39 à 0,42), le rendement en gras (rp = –0,42 à 0,54) et le rendement en protéines (rp = 0,37 à 0,54). Il y avait une corrélation significative entre les estimations de numérations de cellules somatiques et les températures minimales (rp = –0,54 à –0,36). Il y avait une corrélation significative entre la teneur en urée et la température minimale (rp = 0,52). Une plus grande taille d’échantillon est nécessaire pour la recherche future afin de confirmer ces résultats préliminaires. [Traduit par la Rédaction]","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":"102 1","pages":"411 - 419"},"PeriodicalIF":1.0,"publicationDate":"2022-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43636579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of nutritional management regimen and residual feed intake (RFI) classification on RFI reranking and feeding behaviour for finishing beef steers","authors":"N. Ferriman, J. Devos, A. Edwards, K. Wood, C. Campbell, I. Mandell","doi":"10.1139/cjas-2021-0023","DOIUrl":"https://doi.org/10.1139/cjas-2021-0023","url":null,"abstract":"Over 2 years, 207 steers were fed an alfalfa/corn silage diet to determine growing phase (GP) residual feed intake (RFI) classification (low, medium, and high) for individual cattle. Steers were then allocated to two finishing management regimens (MR): MR 1 cattle gradually adjusted to an 84.7% concentrate (dry matter (DM) basis) diet; MR 2 included backgrounding on pasture before finishing using the same diet as MR 1 cattle. Treatment differences in growth performance were examined using GP and finishing phase (FP) RFI classifications. Based on GP RFI classification, FP average daily gain was greater in MR 2 cattle (P = 0.01) with no RFI classification differences for most FP performance traits. However, low-RFI steers had lower FP dry matter intake (DMI) and greater G:F (P ≤ 0.05) than high-RFI steers based on FP RFI classification. Low-RFI steers had fewer visits to the feeder with a lower eating rate than high-RFI steers in both production phases (P ≤ 0.05). Extensive RFI reranking occurred between production phases with 64.3% of steers changing RFI classification. Given extensive reranking in the present study, RFI classification was poorly repeatable between growing and finishing production phases when diverse diets are fed and does not accurately predict feed efficiency.","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47688542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of sod-seeding bloat-free legumes on pasture productivity, steer performance, and production economics","authors":"B. Kelln, G. Penner, S. Acharya, T. McAllister, K. Larson, J. Mckinnon, B. Biligetu, H. Lardner","doi":"10.1139/cjas-2021-0098","DOIUrl":"https://doi.org/10.1139/cjas-2021-0098","url":null,"abstract":"A five-year experiment evaluated the effects of sod-seeding sainfoin and cicer milkvetch into monoculture grass (Lanigan, SK) or legume (Lethbridge, AB) stands on pasture productivity, steer performance, and economics. At Lanigan, sainfoin decreased (treatment × year P = 0.01) from 13% in yr 1 to 2% in yr 2 (% plant population) and did not differ thereafter, while cicer milkvetch, maintained a proportion of 16% in the stand. Forage yield was greater (treatment × year; P < 0.01) in yr 1 in the sainfoin and cicer milkvetch treatments compared to control. DMI of steers was greater only in yr 5 and ADG was greater (P < 0.01) in sainfoin and cicer milkvetch treatments compared to control. At Lethbridge, sainfoin decreased (treatment × year; P = 0.01) from 46 to 17% (% DM yield), while cicer milkvetch maintained its proportion at 11%. Forage yield increased (treatment × year; P < 0.01) only in yr 2 and 3 of sainfoin, compared to cicer milkvetch or control. ADG gain was not affected by treatment. At Lanigan, sainfoin and cicer milkvetch generated greater gross returns compared to control; however, once establishment costs were applied there were no differences in present value of net returns.","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":" ","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43269670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effet du type de stabulation sur le bien-être des vaches laitières en Algérie","authors":"S. Matallah, N. M'hamdi, F. Matallah, Zeineb Bounouala","doi":"10.1139/cjas-2021-0001","DOIUrl":"https://doi.org/10.1139/cjas-2021-0001","url":null,"abstract":"Le but de la présente étude était d'examiner l’effet du type de stabulation sur le bien-être des vaches laitières de race Holstein dans les fermes du Nord-est algérien au niveau de quatre wilayas sur la base du protocole d'évaluation Welfare Quality® pour les bovins. Par conséquent, nous avons appliqué ce protocole à 50 fermes laitières en stabulation libre et à 50 en stabulation entravée. Un total de 2200 vaches laitières a été évalué en période hivernale. Il y avait des différences significatives entre les deux types de logements pour la majorité des critères étudiés : Confort autour de repos (33, 54±5,60 vs 22,34±2,70, absence de soif prolongée (42,40±6,60 vs 20, 40±6,60), facilité de mouvement (100,00±00 vs 44,50± 3,40) et absence de blessures (38,50±10,30 vs 25,12±8,40), cependant l'analyse des mesures liées indique d'importants échecs de gestion dans les deux types de logements dans la région d’étude. En effet, de multiples contraintes ont été observées d’ordre alimentaire (indisponibilité de fourrages et non maitrise du rationnement) et sanitaire (non-respect des normes hygiéniques). Cette situation nécessite d’informer et de communiquer avec l’éleveur sur ce qu’est réellement le bien‐être des animaux afin d’améliorer les conditions d’élevage.","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":"1 1","pages":""},"PeriodicalIF":1.0,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41434432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Proceedings of the 2021 Meeting of the Animal Science Modelling Group","authors":"E. Kebreab, J. Cant, J. Metcalf","doi":"10.1139/CJAS-2022-0008","DOIUrl":"https://doi.org/10.1139/CJAS-2022-0008","url":null,"abstract":"Animal Science Modelling Group meets approximately yearly for one-day meetings. The 2021 meeting was sponsored by Trouw Nutrition (Guelph, ON, Canada), Lallemand Specialties, Inc. (Milwaukee, WI, USA), and Adisseo (Alpharetta, GA, USA). It was held on July 9 as a virtual meeting prior to the virtual ADSA Annual Meeting. Summaries of the papers presented follow. Each summary has been peer reviewed and edited for clarity. The lead author of the summary is the person who presented the paper. Multivariate time series classification mastitis The aim of this study was to investigate the application of time series classification techniques to detect clinical mastitis (CM; binary variable) one-step ahead of time for dairy cattle. Quarter level milking time data from 249 cows were collected daily from automatic milking system (AMS) using DelPro software (DeLaval, Tumba, Sweden) over 12 wk in the summer of 2020. We tested multiple classification algorithms including Decision Tree, Random Forest, Logistic Regression, Naïve Bayes, Gradient Boosting. We tested 16 features (variables) recorded by the AMS unit at each milking event for initial model development: teats not found (binary), blood in milk (binary), kick-offs (binary), occurrence of incompletely milked quarter (binary), previous mastitis history (previous mastitis incident before the milking event; binary), surface plasmon resonance (SPR; 4 levels), milking interval between two successive milking events (hour), milk yield (kg), lactation number, days in milk (day), milk duration (second), electrical conductivity (mS/cm), mean milk IVGP-estimated Kd ’ s for starch and aNDFom were less than IVSD and IVNDFD estimates ( p &lt; 0.001) and more precise. Parameter estimates deduced from the non-linear fitting of IVGP data were statistically significant, biologically reasonable, correlated to parameters determined in independent assays, and more precise. Overall, the mathematical modelling approach of fitting kinetic parameters to multiple carbohydrate fractions with known pool sizes was satisfactorily achieved. ( p 0.13) to be related to PUN. These would indicate that kidney transport activity was not significantly different across animals, and thus would not be the cause of the observed range in MUN across animals. Plasma urea N and MUN were negatively correlated with gut clearance rates and GER:UER ratio ( p ≤ 0.06). This relationship supports the hypothesis that differences in gut urea transport activity among animals causes variation in PUN and MUN concentrations, and that cows with high PUN and MUN are less efficient at recycling PUN to the gastrointestinal tract (GIT) and thus may be more susceptible to ruminal N deficiencies when fed low rumen degradable protein diets. If so, the relationship between a reference MUN concentration and overall N efficiency will be variable. Such biological variation in urea metabolism necessitates an adequate safety margin when setting regulations for maximal MUN levels ","PeriodicalId":9512,"journal":{"name":"Canadian Journal of Animal Science","volume":"102 1","pages":"194 - 200"},"PeriodicalIF":1.0,"publicationDate":"2022-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47570172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}