Alleviative effect of melatonin on the decrease of uterine receptivity caused by blood ammonia through ROS/NF-κB pathway in dairy cow

Individual and combined effects of several isomers of retinoic acid (RA) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) on interferon-gamma (IFN-gamma) secretion by blood mononuclear leukocytes (MNL) from nulliparous and postparturient Holstein cattle were evaluated in vitro. In the first experiment, effects on incubation period (24 to 72 hours) and time of supplementation (0 to 32 hours) with all-trans, 9-cis, 13-cis-, and 9,13-dicis-RAs (0 to 100 nM) on IFN-gamma secretion by pokeweed mitogen (PWM)-stimulated (0 and 10 mug/ml) MNL from nulliparous cattle were evaluated. In the second experiment, MNL from postparturient cows (bled at 0, 2, 4, and 16 days postpartum) were stimulated with PWM (0 and 10 mug/ml) in the presence of RA isomers (9-cis- or 9,13-dicis-RA; 0 to 100 nM), 1,25-(OH)2D3 (0 to 100 nM), or with combinations of these metabolites. The results show that individual isomers of RA had no effect on IFN-gamma secretion by PWM-stimulated MNL from nulliparous or postparturient cows. Furthermore 1,25-dihydroxyvitamin D3 inhibited IFN-gamma secretion by MNL from nulliparous and postparturient dairy cows; however, the degree of inhibition was greater when 9-cis- and 9,13-dicis-RA were also present in the cultures. Finally mononuclear leukocytes from postparturient dairy cows produced substantially less IFN-gamma than did MNL from nulliparous cattle. It is concluded that retinoic acids individually did not affect the capacity of leukocytes from dairy cattle to secrete IFN-gamma. This result is in marked contrast to studies in monogastric species indicating that RAs inhibit IFN-gamma secretion by peripheral blood T cells. Inhibition of IFN-gamma secretion by 1,25-(OH)2D3 was potentiated by 9-cis- and 9,13-di-cis-retinoics acids, suggesting that an excess of dietary vitamins A and D may compromise further the naturally immunosuppressed postparturient dairy cow. Additional research is necessary to determine if the combined effects of these metabolites on IFN-gamma secretion represent an increased susceptibility of the dairy cow to infectious diseases during the periparturient period. Lower secretion of IFN-gamma by MNL from postpartutient dairy cows, relative to nulliparous cattle, suggests that recently-calved cows are naturally immunosuppressed.

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Respiratory Ammonia Output and Blood Ammonia Concentration During Incremental Exercise

International Journal of Sports Medicine ◽

10.1055/s-1999-970268 ◽

1999 ◽

Vol 20 (02) ◽

pp. 71-77

Author(s):

W. Ament ◽

J. Huizenga ◽

E. Kort ◽

T. Mark ◽

R. Grevink ◽

...

Keyword(s):

Ammonia Concentration ◽

Incremental Exercise ◽

Blood Ammonia

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NEW CLOVER CULTIVARS FOR WAIKATO DAIRY PASTURE: ESTABLISHMENT, PRODUCTION AND NITROGEN FIXATION DURING THE FIRST YEAR

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1988.49.1822 ◽

1988 ◽

pp. 207-211

Author(s):

S.F. Ledgard ◽

G.J. Brier ◽

R.N. Watson

Keyword(s):

Nitrogen Fixation ◽

White Clover ◽

Dairy Cow ◽

Red Clover ◽

First Year ◽

Buried Seed

Clover cultivars grown with ryegrass were compared in an establishment year under dairy cow grazing. There was no difference in total annual productton but summer production was greater with Pawera red clover and with Kopu or Pitau white clovers. Clovers differed little in the proportion of nitrogen fixed, except during summer when values were highest for Pawera. Pawera was less prone to nematode attack than white clover cultivars but was more susceptible to clover rot. Resident clovers and high buried seed levels (e.g., 11-91 kg/ha) made introduction of new clover cultivars difficult. Sown clovers established best (50-70% of total clover plants) when drilled into soil treated with dicamba and glyphosate. Keywords: white clover, red clover, nematodes. nitrogen fixation, pasture renovation

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Advancing dairy farming profitability through research

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.2001.63.2427 ◽

2001 ◽

pp. 17-22

Author(s):

J.R. Caradus ◽

D.A. Clark

Keyword(s):

Research And Development ◽

Dairy Cow ◽

Low Cost ◽

Pasture Management ◽

Nitrogen Fertiliser ◽

Grass Endophyte ◽

Forage Species ◽

Development Outcomes ◽

Dairy Cow Nutrition ◽

The Impact

The New Zealand dairy industry recognises that to remain competitive it must continue to invest in research and development. Outcomes from research have ensured year-round provision of low-cost feed from pasture while improving productivity. Some of these advances, discussed in this paper, include the use of white clover in pasture, understanding the impacts of grass endophyte, improved dairy cow nutrition, the use of alternative forage species and nitrogen fertiliser to improve productivity, demonstration of the impact of days-in-milk on profitability, and the use of feed budgeting and appropriate pasture management. Keywords: dairy, profitability, research and development

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Progestation

Acta Endocrinologica ◽

10.1530/acta.0.056s007 ◽

1967 ◽

Vol 56 (3_Suppla) ◽

pp. S7-S45 ◽

Cited By ~ 1

Keyword(s):

Tritiated Thymidine ◽

Succinic Dehydrogenase ◽

Glandular Epithelium ◽

Synthetic Activity ◽

Cell Renewal ◽

Pulse Labelling ◽

Uterine Receptivity ◽

Alkaline Phosphatases ◽

Monocytic Cells ◽

Acid And Alkaline Phosphatases

ABSTRACT Autoradiographic, enzymic and histologic studies on uteri of pregnant rats were carried out to follow the endometrial modifications which take place during progestation (days L0 – L4) and culminate in the state of uterine receptivity essential for ovum-implantation. Pulse labelling with tritiated thymidine (radioactive DNA precursor) on L0, L1 and L2 revealed a sequence of cell renewal in luminal and glandular epithelium and endometrial stroma. On L3 and L4 stromal cells showed extensive incorporation of tritiated thymidine. This synthetic activity was associated with endometrial preparation for decidualization and was evoked at least in part, by the surge of oestrogen on L3. All layers of the uterine wall were heavily infiltrated on L0 and resembled the site of an acute inflammatory reaction. Subsequently, polymorphonuclear infiltration diminished and monocytic cells predominated. On L3 a spatial arrangement was observed: eosinophiles were concentrated in the basal endometrium and monocytic cells in the subepithelial stroma. A comparison was made between such a shift in migratory cells in the uterus and similar phenomena which occur in inflammatory and immune reactions. Activities of acid and alkaline phosphatases, of ATP-ase and succinic dehydrogenase were low on L0 and L1 during the periods of infiltration, degeneration and regeneration of luminal and glandular epithelium. Enzymic activities increased on the following days, (L3 and L4). Vascular dilation and engorgement and endometrial oedema were observed near the blastocysts on L4. Most blastocysts incorporated tritiated thymidine after 14.00 h on L4, but some showed uptake before loss of the zona which occurs usually between 14.00 and 16.00 h; therefore, it was assumed that the permeability of the zona increases prior to being shed. Activities of succinic dehydrogenase and acid and alkaline phosphatases were demonstrable in blastocysts on L4 while they were still »free« in the uterine lumen.

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