Changes in Estrogen, Progesterone, Prolactin and Lactation Traits Associated with Injection of Estradiol-17β and Progesterone into Lactating Cows2

Mollett, T.A.; Erb, R.E.; Monk, E.L.; Malven, P.V.

doi:10.2527/jas1976.423655x

Cited by 29 publications

(19 citation statements)

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“…In this study, through an ovariectomy, we suppressed the cyclic secretion of estrogen and progesterone, which was confirmed by the low levels of plasma progesterone and low uterus weights at slaughter in ovariectomized cows (Johnson et al, 1997;Berry et al, 2003). Previous studies indicated that these 2 steroid hormones negatively affect lactation persistency (Mollett et al, 1976;Athie et al, 1996;Delbecchi et al, 2005). During pregnancy, estrogen and progesterone are widely produced by the fetoplacental unit.…”

Section: Discussionsupporting

confidence: 70%

“…Despite the rapid decreases in estrogen and progesterone plasma concentrations that occurred following insertion of the implant, the authors of that study did not observe any modification in MY within 6 mo after starting the treatment (Delbecchi and Lacasse, 2006). In the studies previously mentioned (Mollett et al, 1976;Athie et al, 1996;Delbecchi et al, 2005), in which estrogen negatively affected MY, the animals were subjected to supraphysiological doses of steroid hormones. Thus, the short-term effect on MY observed in these studies could, in part, be the result of the high estrogen concentrations.…”

Section: Discussionmentioning

confidence: 90%

“…Sex steroids, such as estrogen and progesterone, seem to affect milk yield (MY) negatively during lactation. The administration of exogenous estradiol in mid lactation cows, with or without progesterone, induced a rapid decrease in MY (Mollett et al, 1976;Athie et al, 1996;Delbecchi et al, 2005). Delbecchi et Ovariectomy improves lactation persistency in dairy cows L. Yart ,* † F. Dessauge ,* † L. Finot ,* † S. Barbey , ‡ P. G. Marnet ,* † and V. Lollivier * † 1 3795 al.…”

Section: Introductionmentioning

confidence: 99%

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Ovariectomy improves lactation persistency in dairy cows

Yart

Dessauge

Finot

et al. 2012

Journal of Dairy Science

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A current trend in the dairy industry is to reduce milk yield at the peak of lactation and improve lactation persistency. Lactation persistency is influenced by livestock management factors, such as feeding level or milking frequency, or by physiological status, including reproductive status or calving period. These factors modulate mammary gland apoptosis and tissue remodeling, which determine the rate of decline of milk yield after the lactation peak. Previous studies on lactating cows suggested that ovarian steroids have a negative effect on milk yield after the peak of lactation. In the present study, 4 Holstein × Normande crossbred multiparous cows were ovariectomized at the time of the lactation peak, and 5 cows underwent sham operations. All of the cows were maintained in lactation for 14 mo and milk yield was recorded daily. At slaughter, mammary epithelial cell apoptosis and mammary tissue remodeling were assessed. Ovariectomized cows had improved lactation persistency and presented an average daily milk gain of 2.5 kg compared with the sham-operated cows between mo 6 and 14 of lactation. The ovariectomy appears to have limited the decline in the milk yield after the peak of lactation by reducing mammary epithelial cell apoptosis [by reducing poly(adenosine diphosphate-ribose) polymerase expression] and mammary-tissue remodeling (by reducing matrix metalloproteinase activity). In conclusion, removal of ovarian secretion via ovariectomy improved the cows' lactation persistency.

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Section: Discussionsupporting

confidence: 70%

Section: Discussionmentioning

confidence: 90%

Section: Introductionmentioning

confidence: 99%

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Ovariectomy improves lactation persistency in dairy cows

Yart

Dessauge

Finot

et al. 2012

Journal of Dairy Science

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“…Chez des vaches ou des chèvres en lactation, de telles injections ont fortement diminué la quantité de lait sécré-tée mais accru ses teneurs en matières grasses et en protéines et diminué sa teneur en lactose (Peaker et Linzell, 1974 ;Mollett et al, 1976). Chez des vaches taries, des injections d'oestrogènes pendant 7 jours ont provoqué la sécrétion d'un liquide semblable au colostrum pour la formation duquel la mamelle avait sélectivement prélevé les IgG 1 sanguines, comparativement aux IgG2 et à l'albumine sérique (Smith et al, 1971).…”

Section: Production Et Composition Du Laitunclassified

Composition chimique et coagulation du lait sécrété en fin de gestation et au début de la lactation suivante par des vaches laitières conduites sans période sèche

Rémond

Machebœuf

Rouel

et al. 1997

Lait

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Summary -Chemical composition and clotting properties of milk secreted during late pregnancy by dairy cows managed without the dry period. Among 12 dairy Holstein cows in their first lactation that we attempted to milk until their 2nd calving, five had to be dried off, 9 days before calving on average. Milk progressively enriehed in somatie cells and fat. Increase in proteins was mainly due to caseins but soluble proteins increased relatively more, so that the casein/protein ratio decreased. Increase in IgG 1 explained 80% of the soluble protein augmentation. Free fatty acids measured either in the milkjust milked or after 26 h in refrigerator highly increased in late pregnancy. pH collapsed just before calving (6.22). Rennet clotting time (Ri) and curd firmness time (K20i) measured at natural pH were divided by a nearly 3 factor whereas curd firmness (A30i) increased by approximately 40 %. Measured at standardized pH (6.60) these clotting properties changed similarly but in an attenuated manner. In the succeeding lactation, secretion of milk by these cows was lower than that by the control cows (n = 8) conventionally dried off in the late preceding lactation, but their milk was richer in proteins. dairy cow / late pregnancy / milk composition / clotting pro pert y Résumé -Sur 12 vaches primipares Holstein destinées à être traites jusqu'au deuxième vêlage, 7 ont effectivement pu l'être et 5 ont dû être taries en moyenne 9 jours avant le vêlage. Le lait s'est progressivement enrichi en cellules somatiques et en matières grasses. L'accroissement de la teneur en protéines a été majoritairement dû aux caséines, mais les protéines solubles ont relativement plus augmenté que les caséines, de sorte que la proportion des caséines dans les protéines a diminué. L'accroisAdresses actuelles:*École nationale d'ingénieurs des travaux agricoles, Marmilhat, 63370 Lempdes; **Station de recherches sur la nutrition des herbivores, Inra, Theix, 63122 SaintGenès-Champanelle ; ***Laboratoire de recherche sur la sous-nutrition des ruminants, Inra, Theix, 63122 Saint -Genès-Champanelle, France 616 B Rémond et al seme nt des immunoglobulines Gia expliqué 80 % de celui des protéines solubles. La teneur en acides gras libres dans le lait natif et après 26 heures au réfrigérateur a fortement augmenté en fin de gestation. Le pH du lait s'est effondré à l'approche du vêlage (6,22) et les temps de coagulation (Ri) et de raffermissement (K20i) ont été divisés par un facteur proche de 3, tandis que la fermeté du gel s'accroissait d'environ 40 %. Mesurées à pH standardisé (6,60), ces caractéristiques de coagulation ont évolué de façon semblable, mais atténuée. Au cours de la lactation suivante, la sécrétion de lait de ces animaux a été plus faible que celle d'animaux témoins (n = 8) taris environ 2 mois à la fin de la lactation précédente, mais leur lait a été plus riche en protéines.vache laitière 1 fin de gestation 1 composition du lait 1 coagulation du lait

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“…Outras drogas foram sendo introduzidas aos protocolos como a dexametazona, o bST (Chakriyarat et al, 1978;Hays, 1975;Erb et al, 1976;Mellado et al, 2006;Mollett et al, 1976), a reserpina que induz a liberação de prolactina (Lembowicz;Rabek;Skrzeczkowski, 1982), e as prostaglandinas (Akers, 2002), com a intensão de melhorar a produção, aumentar o volume do úbere, prolongar o tempo de produção e a lactogênese.…”

Section: Protocolos De Indução De Lactação E Sua Utilizaçãounclassified

Influência da indução artificial da lactação na saúde das vacas mestiças

Oliveira¹

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Changes in Estrogen, Progesterone, Prolactin and Lactation Traits Associated with Injection of Estradiol-17β and Progesterone into Lactating Cows2

Cited by 29 publications

References 0 publications

Ovariectomy improves lactation persistency in dairy cows

Ovariectomy improves lactation persistency in dairy cows

Composition chimique et coagulation du lait sécrété en fin de gestation et au début de la lactation suivante par des vaches laitières conduites sans période sèche

Influência da indução artificial da lactação na saúde das vacas mestiças

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