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Martins CMMR, Fonseca DCM, Alves BG, Arcari MA, Ferreira GC, Welter KC, Oliveira CAF, Rennó FP, Santos MV. Effect of dietary crude protein degradability and corn processing on lactation performance and milk protein composition and stability. J Dairy Sci 2019; 102:4165-4178. [PMID: 30879826 DOI: 10.3168/jds.2018-15553] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 01/22/2019] [Indexed: 11/19/2022]
Abstract
The present study aimed to evaluate the effect of crude protein degradability and corn processing on lactation performance, milk protein composition, milk ethanol stability (MES), heat coagulation time (HCT) at 140°C, and the efficiency of N utilization for dairy cows. Twenty Holstein cows with an average of 162 ± 70 d in milk, 666 ± 7 kg of body weight, and 36 ± 7.8 kg/d of milk yield (MY) were distributed in a Latin square design with 5 contemporaneous balanced squares, 4 periods of 21 d, and 4 treatments (factorial arrangement 2 × 2). Treatment factor 1 was corn processing [ground (GC) or steam-flaked corn (SFC)] and factor 2 was crude protein (CP) degradability (high = 10.7% rumen-degradable protein and 5.1% rumen-undegradable protein; low = 9.5% rumen-degradable protein and 6.3% rumen-undegradable protein; dry matter basis). A significant interaction was observed between CP degradability and corn processing on dry matter intake (DMI). When cows were fed GC with low CP degradability, DMI increased by 1.24 kg/d compared with cows fed GC with high CP degradability; however, CP degradability did not change DMI when cows were fed SFC. Similar interactions were observed for MY, HCT, and lactose content. When cows were fed GC diets, high CP degradability reduced MY by 2.3 kg/d, as well as HCT and lactose content, compared with low CP degradability. However, no effect of CP degradability was observed on those variables when cows were fed SFC diets. The SFC diets increased dry matter and starch total-tract digestibility and reduced β-casein (CN) content (% total milk protein) compared with GC diets. Cows fed low-CP degradability diets had higher glycosylated κ-CN content (% total κ-CN) and MES, as well as milk protein content, 3.5% fat-corrected milk, and efficiency of N for milk production, than cows fed high-CP degradability diets. Therefore, GC and high-CP degradability diets reduced milk production and protein stability. Overall, low CP degradability increased the efficiency of dietary N utilization and MES, probably due to changes in casein micelle composition, as CP degradability or corn processing did not change the milk concentration of ionic calcium. The GC diets increased β-CN content, which could contribute to reducing HTC when cows were fed GC and high-CP degradability diets.
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Affiliation(s)
- C M M R Martins
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - D C M Fonseca
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - B G Alves
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - M A Arcari
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - G C Ferreira
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - K C Welter
- Department of Animal Science, School of Food Engineering and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - C A F Oliveira
- Department of Food Engineering, School of Food Engineering and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - F P Rennó
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil
| | - M V Santos
- Department of Animal Nutrition and Production, School of Veterinary Medicine and Animal Science, University of São Paulo, Pirassununga 13635-900, São Paulo, Brazil.
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Le Parc A, Honvo Houéto E, Pigat N, Chat S, Leonil J, Chanat E. The membrane-associated form of α(s1)-casein interacts with cholesterol-rich detergent-resistant microdomains. PLoS One 2014; 9:e115903. [PMID: 25549363 PMCID: PMC4280128 DOI: 10.1371/journal.pone.0115903] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 12/02/2014] [Indexed: 12/19/2022] Open
Abstract
Caseins, the main milk proteins, interact with colloidal calcium phosphate to form the casein micelle. The mesostructure of this supramolecular assembly markedly influences its nutritional and technological functionalities. However, its detailed molecular organization and the cellular mechanisms involved in its biogenesis have been only partially established. There is a growing body of evidence to support the concept that α(s1)-casein takes center stage in casein micelle building and transport in the secretory pathway of mammary epithelial cells. Here we have investigated the membrane-associated form of α(s1)-casein in rat mammary epithelial cells. Using metabolic labelling we show that α(s1)-casein becomes associated with membranes at the level of the endoplasmic reticulum, with no subsequent increase at the level of the Golgi apparatus. From morphological and biochemical data, it appears that caseins are in a tight relationship with membranes throughout the secretory pathway. On the other hand, we have observed that the membrane-associated form of α(s1)-casein co-purified with detergent-resistant membranes. It was poorly solubilised by Tween 20, partially insoluble in Lubrol WX, and substantially insoluble in Triton X-100. Finally, we found that cholesterol depletion results in the release of the membrane-associated form of α(s1)-casein. These experiments reveal that the insolubility of α(s1)-casein reflects its partial association with a cholesterol-rich detergent-resistant microdomain. We propose that the membrane-associated form of α(s1)-casein interacts with the lipid microdomain, or lipid raft, that forms within the membranes of the endoplasmic reticulum, for efficient forward transport and sorting in the secretory pathway of mammary epithelial cells.
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Affiliation(s)
- Annabelle Le Parc
- UR1196 Génomique et Physiologie de la Lactation, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Edith Honvo Houéto
- UR1196 Génomique et Physiologie de la Lactation, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Natascha Pigat
- UR1196 Génomique et Physiologie de la Lactation, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Sophie Chat
- UR1196 Génomique et Physiologie de la Lactation, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
| | - Joëlle Leonil
- UMR1253 Science et Technologie du Lait et de l'Œuf, Institut National de la Recherche Agronomique, Rennes, France
| | - Eric Chanat
- UR1196 Génomique et Physiologie de la Lactation, Institut National de la Recherche Agronomique, Jouy-en-Josas, France
- * E-mail:
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Wang T, Lim JN, Bok JD, Kim JH, Kang SK, Lee SB, Hwang JH, Lee KH, Kang HS, Choi YJ, Kim EJ, Choi SH, Lee HG. Association of protein expression in isolated milk epithelial cells and cis-9, trans-11 conjugated linoleic acid proportions in milk from dairy cows. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2014; 94:1835-1843. [PMID: 24288234 DOI: 10.1002/jsfa.6502] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 11/18/2013] [Accepted: 11/28/2013] [Indexed: 06/02/2023]
Abstract
BACKGROUND The effects of the individual variation among dairy cows on the synthesis of cis-9, trans-11 conjugated linoleic acid (CLA) are still not well characterised. Therefore, the protein expression profiles of isolated milk epithelial cells (MECs) were detected by two-dimensional electrophoresis and their correlation with the various proportion of cis-9, trans-11 CLA were evaluated. RESULTS Although animals were offered the same diet, the proportion of cis-9, trans-11 CLA in group High (1.02 ± 0.10%) was twice as high as that in group Low (0.59 ± 0.14%) (P < 0.05). MECs with the characteristics of native epithelial cells were successfully isolated from the milk and these cells had no obvious RNA degradation or were hardly contaminated with leucocytes or blood red cells. Moreover, the protein expression pattern of cathelicidin 5 in isolated MECs was positive, whereas annexin I (confirmed by real-time polymerase chain reaction), ZW10 interactor and κ-casein were negatively related to the proportion of cis-9, trans-11 CLA in the milk fat. CONCLUSION The varied individual content of cis-9, trans-11 CLA in cows may be associated with annexin I. These findings may provide some theoretical basis for studies concerning the effects of the individual variation among dairy cows of the synthesis of cis-9, trans-11 CLA. © 2013 Society of Chemical Industry.
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Affiliation(s)
- Tao Wang
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, 130118, P.R. China; Key Laboratory of Animal Nutrition and Feed Science, Jilin Province, Jilin Agricultural University, Changchun, 130118, P.R. China
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Le Parc A, Leonil J, Chanat E. AlphaS1-casein, which is essential for efficient ER-to-Golgi casein transport, is also present in a tightly membrane-associated form. BMC Cell Biol 2010; 11:65. [PMID: 20704729 PMCID: PMC2928771 DOI: 10.1186/1471-2121-11-65] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2010] [Accepted: 08/12/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Caseins, the main milk proteins, aggregate in the secretory pathway of mammary epithelial cells into large supramolecular structures, casein micelles. The role of individual caseins in this process and the mesostructure of the casein micelle are poorly known. RESULTS In this study, we investigate primary steps of casein micelle formation in rough endoplasmic reticulum-derived vesicles prepared from rat or goat mammary tissues. The majority of both alphaS1- and beta-casein which are cysteine-containing casein was dimeric in the endoplasmic reticulum. Saponin permeabilisation of microsomal membranes in physico-chemical conditions believed to conserve casein interactions demonstrated that rat immature beta-casein is weakly aggregated in the endoplasmic reticulum. In striking contrast, a large proportion of immature alphaS1-casein was recovered in permeabilised microsomes when incubated in conservative conditions. Furthermore, a substantial amount of alphaS1-casein remained associated with microsomal or post-ER membranes after saponin permeabilisation in non-conservative conditions or carbonate extraction at pH11, all in the presence of DTT. Finally, we show that protein dimerisation via disulfide bond is involved in the interaction of alphaS1-casein with membranes. CONCLUSIONS These experiments reveal for the first time the existence of a membrane-associated form of alphaS1-casein in the endoplasmic reticulum and in more distal compartments of the secretory pathway of mammary epithelial cells. Our data suggest that alphaS1-casein, which is required for efficient export of the other caseins from the endoplasmic reticulum, plays a key role in early steps of casein micelle biogenesis and casein transport in the secretory pathway.
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Affiliation(s)
- Annabelle Le Parc
- INRA, UR1196 Génomique et Physiologie de la Lactation, Domaine de Vilvert, F-78352 Jouy-en-Josas cedex, France
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