The Effect of Pasture Nitrate Concentration and Concentrate Intake after Turnout on Embryo Growth and Viability in the Lactating Dairy Cow

Laven, Richard; Biggadike, H. J.; Allison, R.

doi:10.1046/j.1439-0531.2002.00342.x

Cited by 19 publications

(9 citation statements)

References 2 publications

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“…These field observations have been documented by several authors [6,9]. Corollary to this were reports in this study of neonatal and perinatal calf mortalities as well as low birth weights, reproductive failures, reduced lactation and hypothyroidism due to maternal chronic nitrate poisoning.…”

Section: Discussionsupporting

confidence: 81%

Environmental Factors Associated with Nitrate Poisoning in Livestock in Botswana

Mg¹,

Ez²

2012

J Pet Environ Biotechnol

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Some cases of sudden deaths in cattle, sheep and goats reported to the National Veterinary Laboratory, Gaborone were investigated. The clinical signs included: stupor, weakness, staggering, trembling, dyspnoea (difficulty in breathing), salivation, diarrhoea, and convulsions for those in extremis. The most consistent sign was the muddy coloured mucous membranes. Necropsy findings included: marked gastroenteritis and generalized congestion and petichiation in all internal body organs and chocolate brown coloured blood that clotted poorly. The presence of nitrate/nitrite in the blood of live animals, amniotic fluid, urine, ocular fluid, urine, drinking water and consumed forage were demonstrated by the diphenylamine test and subsequently confirmed by Gries test. Further confirmation of nitrate/ nitrite poisoning was by response to therapeutic intervention with methylene blue using the intravenous route of inoculation.Environmental factors that may have contributed to the poisoning episodes included, drought, high ambient temperatures, low cloud cover, soil leaching after flooding, soil moisture content and forage nitrogen content and natural geoformations associated with high nitrate content in the water. This is the first account of confirmed cases of nitrate/ nitrite poisoning in livestock in Botswana.

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Section: Discussionsupporting

confidence: 81%

Environmental Factors Associated with Nitrate Poisoning in Livestock in Botswana

Mg¹,

Ez²

2012

J Pet Environ Biotechnol

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“…A high mean plasma urea concentration was associated with a significant reduction in pregnancy rate in dairy cows [ 59 , 60 ]. In contrast, high plasma urea concentrations due to high levels of dietary nitrogen had no effect on parameters of fertility in other studies [ 61 , 62 , 63 ]. Moreover, high blood urea and the metabolic indicators of NEB often occur simultaneously in high-yielding cows making it difficult to separate out any individual effects on subsequent fertility [ 58 ].…”

Section: Discussionmentioning

confidence: 71%

Relationships between Circulating Urea Concentrations and Endometrial Function in Postpartum Dairy Cows

Cheng¹,

Oguejiofor²,

Swangchan-Uthai³

et al. 2015

Animals

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Simple SummaryDairy cows fed high levels of protein to increase milk yield tend to have reduced fertility but the reasons behind this are unclear. Differing dietary protein levels are reflected in altered urea concentrations in both blood and other tissues including the uterus. We showed that the circulating urea concentration was highly correlated to changed expression levels of many genes in the endometrium shortly after calving. These were predominantly associated with tissue repair, innate immunity and lipid metabolism. A subsequent study found no effect of altered urea concentration on endometrial gene expression in vitro implying that the dietary influence is indirect.AbstractBoth high and low circulating urea concentrations, a product of protein metabolism, are associated with decreased fertility in dairy cows through poorly defined mechanisms. The rate of involution and the endometrial ability to mount an adequate innate immune response after calving are both critical for subsequent fertility. Study 1 used microarray analysis to identify genes whose endometrial expression 2 weeks postpartum correlated significantly with the mean plasma urea per cow, ranging from 3.2 to 6.6 mmol/L. The biological functions of 781 mapped genes were analysed using Ingenuity Pathway Analysis. These were predominantly associated with tissue turnover (e.g., BRINP1, FOXG1), immune function (e.g., IL17RB, CRISPLD2), inflammation (e.g., C3, SERPINF1, SERPINF2) and lipid metabolism (e.g., SCAP, ACBD5, SLC10A). Study 2 investigated the relationship between urea concentration and expression of 6 candidate genes (S100A8, HSP5A, IGF1R, IL17RB, BRINP1, CRISPLD2) in bovine endometrial cell culture. These were treated with 0, 2.5, 5.0 or 7.5 mmol/L urea, equivalent to low, medium and high circulating values with or without challenge by bacterial lipopolysaccharide (LPS). LPS increased S100A8 expression as expected but urea treatment had no effect on expression of any tested gene. Examination of the genes/pathways involved suggests that plasma urea levels may reflect variations in lipid metabolism. Our results suggest that it is the effects of lipid metabolism rather than the urea concentration which probably alter the rate of involution and innate immune response, in turn influencing subsequent fertility.

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“…A more recent study examined the effects on embryo growth and viability in 48 cows between 2 and 8 weeks of gestation that were feeding on heavily fertilized grass containing high levels of nitrogen compared with those in control pasture (Laven et al 2002). No evidence was found that embryo survival or growth was affected from 20 days onward in pregnant cows grazing in either pasture.…”

Section: Reproductive Toxicitymentioning

confidence: 99%

A Review of Nitrates in Drinking Water: Maternal Exposure and Adverse Reproductive and Developmental Outcomes

Manassaram

Backer

Moll

2006

Environ Health Perspect

202

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In this review we present an update on maternal exposure to nitrates in drinking water in relation to possible adverse reproductive and developmental effects, and also discuss nitrates in drinking water in the United States. The current standard for nitrates in drinking water is based on retrospective studies and approximates a level that protects infants from methemoglobinemia, but no safety factor is built into the standard. The current standard applies only to public water systems. Drinking water source was related to nitrate exposure (i.e., private systems water was more likely than community system water to have nitrate levels above the maximum contaminant limit). Animal studies have found adverse reproductive effects resulting from higher doses of nitrate or nitrite. The epidemiologic evidence of a direct exposure–response relationship between drinking water nitrate level and adverse reproductive effect is still not clear. However, some reports have suggested an association between exposure to nitrates in drinking water and spontaneous abortions, intrauterine growth restriction, and various birth defects. Uncertainties in epidemiologic studies include the lack of individual exposure assessment that would rule out confounding of the exposure with some other cause. Nitrates may be just one of the contaminants in drinking water contributing to adverse outcomes. We conclude that the current literature does not provide sufficient evidence of a causal relationship between exposure to nitrates in drinking water and adverse reproductive effects. Future studies incorporating individual exposure assessment about users of private wells—the population most at risk—should be considered.

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The Effect of Pasture Nitrate Concentration and Concentrate Intake after Turnout on Embryo Growth and Viability in the Lactating Dairy Cow

Cited by 19 publications

References 2 publications

Environmental Factors Associated with Nitrate Poisoning in Livestock in Botswana

Environmental Factors Associated with Nitrate Poisoning in Livestock in Botswana

Relationships between Circulating Urea Concentrations and Endometrial Function in Postpartum Dairy Cows

A Review of Nitrates in Drinking Water: Maternal Exposure and Adverse Reproductive and Developmental Outcomes

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