{"title":"补充维生素 A 对圈养肉牛及其犊牛肝脏视黄醇浓度的影响","authors":"H.F. Speer , K.H. Wilke , M.E. Drewnoski","doi":"10.15232/aas.2024-02564","DOIUrl":null,"url":null,"abstract":"<div><h3>Objective</h3><p>Our objective was to evaluate how the amount of vitamin A supplementation provided from mid- gestation through early lactation affected liver retinol con- centrations of a cow and, subsequently, of her calf in a confinement system.</p></div><div><h3>Materials and Methods</h3><p>Multiparous Angus cross beef cows (n = 54; BCS = 6.0) in mid-gestation (5 mo) with an initial BW of 578 kg (SD = ±74) were stratified by BCS and time spent in the confinement system and were assigned to pen (n = 9). Pens were assigned (n = 3) to each of the following treatments: current NASEM (2016) recommendation (31,000 IU/d; 1X) or 3 times (93,000 IU/d; 3X) or 5 times (155,000 IU/d; 5X) the cur- rent NASEM recommendation for supplemental vitamin A. Cows were limit fed a diet consisting of wheat straw, corn silage, and wet distillers grains. Liver biopsies were collected from cows 24 d before treatment initiation and at d 40 and 81 of supplementation, and both cows and calves were sampled 32 d after calving (d 165 of supplementa- tion, SD = ±22).</p></div><div><h3>Results and Discussion</h3><p>No differences in initial cow liver retinol concentrations (mean 186 μg/g of DM) were observed between treatments. A significant treatment × day interaction was observed for cow liver retinol. Liver retinol concentrations of 1X remained below adequate ref- erence ranges (300–700 μg/g of DM) throughout the study (≤189 μg/g of DM), whereas 3X and 5X were elevated into the adequate range by d 81 (334 and 412 μg/g of DM, respectively). Calf liver retinol concentration also differed among treatments, as calves of cows in 1X had lesser liver concentrations than 3X and 5X calves, which did not dif- fer. Liver retinol concentrations considered adequate for calves at 32 d of age (100–350 μg/g of DM) were not observed in 1X calves (51 μg/g of DM) but were observed in calves from 3X and 5X cows (119 and 165 μg/g of DM, respectively).</p></div><div><h3>Implications</h3><p>Providing the amount of supplemental vitamin A recommended by NASEM to cows in a long- term drylot did not result in cow or calf liver retinol con- centrations within the adequate reference ranges. Supple- menting cows with 93,000 IU/d of vitamin A for 165 d brought liver retinol concentrations of cows and their calves up within adequate reference ranges. Cows being fed diets consisting mainly of brown forages and concen- trates long term may need more supplemental vitamin A than currently recommended to ensure calves receive enough vitamin A from colostrum.</p></div>","PeriodicalId":8519,"journal":{"name":"Applied Animal Science","volume":null,"pages":null},"PeriodicalIF":1.4000,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2590286524000946/pdf?md5=5c85a60c406a629ed14b476df91f78d6&pid=1-s2.0-S2590286524000946-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Effects of vitamin A supplementation on liver retinol concentrations of beef cows and their calves managed in confinement\",\"authors\":\"H.F. Speer , K.H. Wilke , M.E. Drewnoski\",\"doi\":\"10.15232/aas.2024-02564\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><h3>Objective</h3><p>Our objective was to evaluate how the amount of vitamin A supplementation provided from mid- gestation through early lactation affected liver retinol con- centrations of a cow and, subsequently, of her calf in a confinement system.</p></div><div><h3>Materials and Methods</h3><p>Multiparous Angus cross beef cows (n = 54; BCS = 6.0) in mid-gestation (5 mo) with an initial BW of 578 kg (SD = ±74) were stratified by BCS and time spent in the confinement system and were assigned to pen (n = 9). Pens were assigned (n = 3) to each of the following treatments: current NASEM (2016) recommendation (31,000 IU/d; 1X) or 3 times (93,000 IU/d; 3X) or 5 times (155,000 IU/d; 5X) the cur- rent NASEM recommendation for supplemental vitamin A. Cows were limit fed a diet consisting of wheat straw, corn silage, and wet distillers grains. Liver biopsies were collected from cows 24 d before treatment initiation and at d 40 and 81 of supplementation, and both cows and calves were sampled 32 d after calving (d 165 of supplementa- tion, SD = ±22).</p></div><div><h3>Results and Discussion</h3><p>No differences in initial cow liver retinol concentrations (mean 186 μg/g of DM) were observed between treatments. A significant treatment × day interaction was observed for cow liver retinol. Liver retinol concentrations of 1X remained below adequate ref- erence ranges (300–700 μg/g of DM) throughout the study (≤189 μg/g of DM), whereas 3X and 5X were elevated into the adequate range by d 81 (334 and 412 μg/g of DM, respectively). Calf liver retinol concentration also differed among treatments, as calves of cows in 1X had lesser liver concentrations than 3X and 5X calves, which did not dif- fer. Liver retinol concentrations considered adequate for calves at 32 d of age (100–350 μg/g of DM) were not observed in 1X calves (51 μg/g of DM) but were observed in calves from 3X and 5X cows (119 and 165 μg/g of DM, respectively).</p></div><div><h3>Implications</h3><p>Providing the amount of supplemental vitamin A recommended by NASEM to cows in a long- term drylot did not result in cow or calf liver retinol con- centrations within the adequate reference ranges. Supple- menting cows with 93,000 IU/d of vitamin A for 165 d brought liver retinol concentrations of cows and their calves up within adequate reference ranges. Cows being fed diets consisting mainly of brown forages and concen- trates long term may need more supplemental vitamin A than currently recommended to ensure calves receive enough vitamin A from colostrum.</p></div>\",\"PeriodicalId\":8519,\"journal\":{\"name\":\"Applied Animal Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.4000,\"publicationDate\":\"2024-09-16\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2590286524000946/pdf?md5=5c85a60c406a629ed14b476df91f78d6&pid=1-s2.0-S2590286524000946-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Animal Science\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2590286524000946\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"AGRICULTURE, DAIRY & ANIMAL SCIENCE\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Animal Science","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2590286524000946","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"AGRICULTURE, DAIRY & ANIMAL SCIENCE","Score":null,"Total":0}
Effects of vitamin A supplementation on liver retinol concentrations of beef cows and their calves managed in confinement
Objective
Our objective was to evaluate how the amount of vitamin A supplementation provided from mid- gestation through early lactation affected liver retinol con- centrations of a cow and, subsequently, of her calf in a confinement system.
Materials and Methods
Multiparous Angus cross beef cows (n = 54; BCS = 6.0) in mid-gestation (5 mo) with an initial BW of 578 kg (SD = ±74) were stratified by BCS and time spent in the confinement system and were assigned to pen (n = 9). Pens were assigned (n = 3) to each of the following treatments: current NASEM (2016) recommendation (31,000 IU/d; 1X) or 3 times (93,000 IU/d; 3X) or 5 times (155,000 IU/d; 5X) the cur- rent NASEM recommendation for supplemental vitamin A. Cows were limit fed a diet consisting of wheat straw, corn silage, and wet distillers grains. Liver biopsies were collected from cows 24 d before treatment initiation and at d 40 and 81 of supplementation, and both cows and calves were sampled 32 d after calving (d 165 of supplementa- tion, SD = ±22).
Results and Discussion
No differences in initial cow liver retinol concentrations (mean 186 μg/g of DM) were observed between treatments. A significant treatment × day interaction was observed for cow liver retinol. Liver retinol concentrations of 1X remained below adequate ref- erence ranges (300–700 μg/g of DM) throughout the study (≤189 μg/g of DM), whereas 3X and 5X were elevated into the adequate range by d 81 (334 and 412 μg/g of DM, respectively). Calf liver retinol concentration also differed among treatments, as calves of cows in 1X had lesser liver concentrations than 3X and 5X calves, which did not dif- fer. Liver retinol concentrations considered adequate for calves at 32 d of age (100–350 μg/g of DM) were not observed in 1X calves (51 μg/g of DM) but were observed in calves from 3X and 5X cows (119 and 165 μg/g of DM, respectively).
Implications
Providing the amount of supplemental vitamin A recommended by NASEM to cows in a long- term drylot did not result in cow or calf liver retinol con- centrations within the adequate reference ranges. Supple- menting cows with 93,000 IU/d of vitamin A for 165 d brought liver retinol concentrations of cows and their calves up within adequate reference ranges. Cows being fed diets consisting mainly of brown forages and concen- trates long term may need more supplemental vitamin A than currently recommended to ensure calves receive enough vitamin A from colostrum.