{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:14:58Z","timestamp":1760148898787,"version":"build-2065373602"},"reference-count":52,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2023,6,15]],"date-time":"2023-06-15T00:00:00Z","timestamp":1686787200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"University of Tennessee Institute of Agriculture","award":["1019048"],"award-info":[{"award-number":["1019048"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>Replacement heifer development is one of the most critical components in beef production. The composition of the ideal uterine environment could maximize fertility and reproductive efficiency. Our hypothesis was that protein supplementation would affect the uterine environment of beef heifers without inhibiting development or reproduction. To test the effects of dietary supplementation on these outcomes, a randomized complete block design with repeated measures was implemented. Angus heifers (n = 60) were blocked by body weight (BW) and randomly assigned to one of three supplemental protein treatment groups (10% (CON), 20% (P20), and 40% (P40)). Mixed model ANOVAs were used to determine whether protein supplementation treatments, time, and the interaction or protein supplementation, semen exposure, and the interaction influenced uterine luminal fluid (ULF) and pregnancy outcomes. Amino acids (AAs) were impacted (p &lt; 0.001), specifically, the essential AAs: Arg, Iso, Leu, Val, His, Lys, Met, Phe, Trp. Protein supplementation influenced multiple AAs post-insemination: Arg (p = 0.03), CC (p = 0.05), 1-MH (p = 0.001), and Orn (p = 0.03). In conclusion, protein supplementation did not affect the reproductive development via puberty attainment or the timing of conception even with alterations in growth. However, uterine AA concentrations did change throughout development and protein supplementation influenced ULF d 14 post-insemination, which may affect the conception rates.<\/jats:p>","DOI":"10.3390\/ani13121995","type":"journal-article","created":{"date-parts":[[2023,6,15]],"date-time":"2023-06-15T01:32:57Z","timestamp":1686792777000},"page":"1995","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["The Impacts of Supplemental Protein during Development on Amino Acid Concentrations in the Uterus and Pregnancy Outcomes of Angus Heifers"],"prefix":"10.3390","volume":"13","author":[{"given":"Kiernan J.","family":"Brandt","sequence":"first","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Taylor B.","family":"Ault-Seay","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rebecca R.","family":"Payton","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liesel G.","family":"Schneider","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J. Lannett","family":"Edwards","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1980-2105","authenticated-orcid":false,"given":"Phillip R.","family":"Myer","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Justin D.","family":"Rhinehart","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kyle J.","family":"McLean","sequence":"additional","affiliation":[{"name":"Department of Animal Science, University of Tennessee, Knoxville, TN 37996, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,6,15]]},"reference":[{"key":"ref_1","unstructured":"USDA-NASS (2019). Cattle Inventory, USDA APHIS:VS:CEAH."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"4018","DOI":"10.2527\/1992.70124018x","article-title":"Management considerations in heifer development and puberty","volume":"70","author":"Patterson","year":"1992","journal-title":"J. Anim. Sci."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1166","DOI":"10.2527\/jas.2011-4569","article-title":"Physiology and endocrinology symposium: Nutritional aspects of developing replacement heifers","volume":"90","author":"Funston","year":"2012","journal-title":"J. Anim. Sci."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"602","DOI":"10.2527\/jas1969.294602x","article-title":"Puberty in crossbred and straightbred beef heifers on two levels of feed","volume":"29","author":"Wiltbank","year":"1969","journal-title":"J. Anim. Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"293","DOI":"10.2527\/jas1982.552293x","article-title":"Postinflection Growth in straightbred and Crossbred Cattle, II, Relationships among Weight, Height and Pubertal Characters","volume":"55","author":"Nelsen","year":"1982","journal-title":"J. Anim. Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1016\/0093-691X(82)90185-6","article-title":"Effect of level of nutrition on onset of puberty and conception rates of Zebu heifers","volume":"18","author":"Oyedipe","year":"1982","journal-title":"Theriogenology"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"6","DOI":"10.2527\/af.2013-0027","article-title":"Management of age at puberty in beef heifers to optimize efficiency of beef production","volume":"3","author":"Day","year":"2013","journal-title":"Anim. Front."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Utter, S.D., Houghton, P.L., Corah, L.R., Simms, D.D., Spire, M.F., and Butine, M.D. (1994). Factors Influencing First-Service Conception and Overall Pregnancy Rates in Commercial Beef Heifers, Kansas State University. Kansas State University Research Report.","DOI":"10.4148\/2378-5977.2075"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1141286","DOI":"10.3389\/fvets.2023.1141286","article-title":"Stayability in Simmental cattle as affected by muscularity and body condition score between calvings","volume":"10","author":"Buonaiuto","year":"2023","journal-title":"Front. Vet. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"127","DOI":"10.2527\/jas1971.321127x","article-title":"Relationships among weight gains, age at puberty and reproductive performance in heifers","volume":"32","author":"Short","year":"1971","journal-title":"J. Anim. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1272","DOI":"10.2527\/jas1982.5561272x","article-title":"Effects of postweaning rate of gain on onset of puberty and productive performance of heifers of different breeds","volume":"55","author":"Ferrell","year":"1982","journal-title":"J. Anim. Sci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"694","DOI":"10.2527\/1993.713694x","article-title":"Reduction of fertility and alteration of uterine pH in heifers fed excess ruminally degradable protein","volume":"71","author":"Elrod","year":"1993","journal-title":"J. Anim. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2843","DOI":"10.2527\/1993.71112843x","article-title":"The effects of ruminally undegradable protein, propionic acid, and monensin on puberty and pregnancy in beef heifers","volume":"71","author":"Lalman","year":"1993","journal-title":"J. Anim Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"283","DOI":"10.2527\/2004.821283x","article-title":"Effect of increasing levels of undegradable intake protein on metabolic and endocrine factors in estrous cycling beef heifers","volume":"82","author":"Kane","year":"2004","journal-title":"J. Anim. Sci."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1296","DOI":"10.1093\/jas\/skz013","article-title":"Maternal nutrition and stage of early pregnancy in beef heifers: Impacts on hexose and AA concentrations in maternal and fetal fluids","volume":"97","author":"Crouse","year":"2019","journal-title":"J. Anim. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Forde, N., Simintiras, C.A., Sturmey, R., Mamo, S., Kelly, A.K., Spencer, T.E., Bazer, F.W., and Lonergan, P. (2014). Amino acids in the uterine luminal fluid reflects the temporal changes in transporter expression in the endometrium and conceptus during early pregnancy in cattle. PLoS ONE, 9.","DOI":"10.1371\/journal.pone.0100010"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"3127","DOI":"10.2527\/jas.2013-7404","article-title":"Comparison of three CIDR-based fixed-time AI protocols in beef heifers","volume":"92","author":"Bridges","year":"2014","journal-title":"J. Anim. Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/S0378-4320(99)00088-3","article-title":"Embryo and foetal loss in beef heifers between day 14 of gestation and full term","volume":"58","author":"Dunne","year":"2000","journal-title":"Anim. Reprod. Sci."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1376","DOI":"10.2527\/jas1975.4151376x","article-title":"Uterine Protein Secretions: Relationship to Development of the Conceptus","volume":"41","author":"Bazer","year":"1975","journal-title":"J. Anim. Sci."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"445","DOI":"10.1002\/mrd.20607","article-title":"Amino acids in oviduct and uterine fluid and blood plasma during the estrous cycle in the bovine","volume":"74","author":"Hugentobler","year":"2007","journal-title":"Mol. Reprod. Dev."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"685","DOI":"10.1530\/REP-10-0533","article-title":"Increase of essential amino acids in the bovine uterine lumen during preimplantation development","volume":"141","author":"Groebner","year":"2011","journal-title":"Reproduction"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1364","DOI":"10.3168\/jds.2013-6954","article-title":"Amino acid concentrations in uterine fluid during early pregnancy differ in fertile and subfertile dairy cow strains","volume":"97","author":"Meier","year":"2014","journal-title":"J. Dairy Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"63","DOI":"10.2527\/1995.73163x","article-title":"Effects of postweaning diet on age and weight at puberty and milk production of heifers","volume":"73","author":"Marston","year":"1995","journal-title":"J. Anim. Sci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"603","DOI":"10.2527\/jas1988.663603x","article-title":"Carcass composition in mature Hereford cows: Estimation and effect on daily metabolizable energy requirement during winter","volume":"66","author":"Wagner","year":"1988","journal-title":"J. Anim. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"217","DOI":"10.15232\/S1080-7446(15)31832-5","article-title":"Effects of a timed insemination following synchronization of ovulation using the Ovsynch or CO-Synch protocol in beef cows","volume":"14","author":"Geary","year":"1998","journal-title":"Prof. Anim. Sci."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1584","DOI":"10.3168\/jds.2015-10192","article-title":"Circulating concentrations of bovine pregnancy-associated glycoproteins and late embryonic mortality in lactating dairy herds","volume":"99","author":"Pohler","year":"2015","journal-title":"J. Dairy Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2653","DOI":"10.2527\/2005.83112653x","article-title":"Incidence of puberty in beef heifers fed high- or low-starch diets for different periods before breeding","volume":"83","author":"Ciccioli","year":"2005","journal-title":"J. Anim. Sci."},{"key":"ref_28","first-page":"249","article-title":"Management strategies for improving lifetime reproductive success in beef heifers","volume":"30","author":"Perry","year":"2012","journal-title":"Proc. Appl. Reprod. Strateg. Beef Cattle"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"645","DOI":"10.2527\/jas1987.653645x","article-title":"Pregnancy rates of beef heifers bred either on puberal or third estrus","volume":"65","author":"Byerley","year":"1987","journal-title":"J. Anim. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1016\/j.theriogenology.2008.05.032","article-title":"Developing replacement beef heifers","volume":"70","author":"Engelken","year":"2008","journal-title":"Theriogenology"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3153","DOI":"10.2527\/jas1988.66123153x","article-title":"Relationships among weight change, body condition and reproductive performance of range beef cows","volume":"66","author":"Selk","year":"1988","journal-title":"J. Anim. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1016\/j.livsci.2014.05.010","article-title":"Feeding excess crude protein to gestating and lactating beef heifers: Impact on parturition, milk composition, ovarian function, reproductive efficiency and pre-weaning progeny growth","volume":"167","author":"Gunn","year":"2014","journal-title":"Livest. Sci."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2298","DOI":"10.2527\/jas.2007-0076","article-title":"Utilization of dried distillers grains for developing beef heifers","volume":"85","author":"Martin","year":"2007","journal-title":"J. Anim. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1194","DOI":"10.3168\/jds.S0022-0302(03)73703-5","article-title":"Disruption of bovine oocytes and preimplantation embryos by urea and acidic pH","volume":"86","author":"Ocon","year":"2003","journal-title":"J. Dairy Sci."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"3441","DOI":"10.1093\/humrep\/13.12.3441","article-title":"Intracellular pH of the mouse preimplantation embryo: Amino acids act as buffers of intracellular pH","volume":"13","author":"Edwards","year":"1998","journal-title":"Hum. Reprod."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1002\/(SICI)1098-2795(199912)54:4<396::AID-MRD10>3.0.CO;2-6","article-title":"Regulation of intracellular pH in bovine oocytes and cleavage stage embryos","volume":"54","author":"Lane","year":"1999","journal-title":"Mol. Reprod. Dev."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1016\/j.domaniend.2007.09.003","article-title":"Effect of preovulatory concentrations of estradiol and initiation of standing estrus on uterine pH in beef cows","volume":"34","author":"Perry","year":"2008","journal-title":"Dom. Anim. Endocrin."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"2928","DOI":"10.2527\/jas.2008-1181","article-title":"Effects of standing estrus and supplemental estradiol on changes in uterine pH during a fixed-time artificial insemination protocol","volume":"86","author":"Perry","year":"2008","journal-title":"J. Anim. Sci."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"675","DOI":"10.4141\/cjas91-083","article-title":"The effect of postulating diet intake on embryonic and fetal survival, and litter size in gilts","volume":"71","author":"Dyck","year":"1991","journal-title":"Can. J. Anim. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"253","DOI":"10.1071\/RD9940253","article-title":"Effect of post-ovulation nutritional status in ewes on early conceptus survival and growth in vivo and luteotrophic protein secretion in vitro","volume":"6","author":"Wallace","year":"1994","journal-title":"Reprod. Fert. Dev."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1854","DOI":"10.3168\/jds.S0022-0302(83)82023-2","article-title":"Relationship of dietary crude protein to composition of uterine secretions and blood in high-producing postpartum dairy cows","volume":"66","author":"Jordan","year":"1983","journal-title":"J. Dairy Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1186","DOI":"10.2527\/jas.2012-5518","article-title":"Influence of nitrogen and sulfur intake on bovine uterine pH throughout the luteal phase","volume":"91","author":"Grant","year":"2013","journal-title":"J. Anim. Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"684","DOI":"10.1071\/RD09129","article-title":"Effects of changes in the concentration of systemic progesterone on ions, amino acids and energy substrates in cattle oviduct and uterine fluid and blood","volume":"22","author":"Hugentobler","year":"2010","journal-title":"Reprod. Fertil. Dev."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"625","DOI":"10.1017\/S1751731116001889","article-title":"Effects of excess metabolizable protein on ovarian function and circulating amino acids of beef cows: 1. Excessive supply from corn gluten meal or soybean meal","volume":"11","author":"Geppert","year":"2017","journal-title":"Animal"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"1813","DOI":"10.1095\/biolreprod.102.012971","article-title":"Developmental changes of amino acids in ovine fetal fluids","volume":"68","author":"Kwon","year":"2003","journal-title":"Biol. Reprod."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"86","DOI":"10.1095\/biolreprod.108.071597","article-title":"Select nutrients in the ovine uterine lumen. i. amino acids, glucose, and ions in uterine lumenal flushings of cyclic and pregnant ewes","volume":"80","author":"Gao","year":"2009","journal-title":"Biol. Reprod."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1113\/expphysiol.1989.sp003316","article-title":"Uptake of amino acids and ammonia at mid-gestation by the fetal lamb","volume":"74","author":"Bell","year":"1989","journal-title":"Q. J. Exp. Physiol."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1146\/annurev-animal-022513-114113","article-title":"Amino acid nutrition in animals: Protein synthesis and beyond","volume":"2","author":"Wu","year":"2014","journal-title":"Annu. Rev. Anim. Biosci."},{"key":"ref_49","unstructured":"Maiese, K. (2016). Molecules to Medicine with mTOR, Adacemic Press."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"1094","DOI":"10.1095\/biolreprod.111.094722","article-title":"Uterine histotroph and conceptus development: Select nutrients and secreted phosphoprotein 1 affect mechanistic target of rapamycin cell signaling in ewes","volume":"85","author":"Bazer","year":"2011","journal-title":"Biol. Reprod."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1017\/S175173111400086X","article-title":"Optimising reproductive performance of beef cows and replacement heifers","volume":"8","author":"Diskin","year":"2014","journal-title":"Animal"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"541","DOI":"10.1093\/tas\/txy118","article-title":"Developmental and reproductive characteristics of beef heifers classified by number of estrous cycles experienced by start of first breeding","volume":"3","author":"Roberts","year":"2019","journal-title":"Trans. Anim. 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