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Dairy cows undergo dramatic metabolic changes and impaired immune system function in the transition period; thus, they are very susceptible to peripartum disease. Vitamin D as an immune-modulatory agent may have protective effects against oxidative stress and numerous diseases. Our objective in this study was to investigate the changes in 25(OH)D concentrations in dairy cattle during the transition period and its association with some inflammatory and oxidative stress markers. Twenty-three healthy cows were selected from two commercial farms and were sampled 1 week prepartum and 1 week and 3 weeks postpartum. 25(OH)D, IL-4, IL-10, INF-γ, Hap, IgG, MDA, and TAC amounts were measured. Time had significant effects on 25(OH)D concentrations and its concentration was decreased 1 week after parturition and then increased. The consumption of vitamin D for calcium homeostasis and the proper immune system functioning may be the reason for decreasing in its amounts after parturition. Pearson test showed that in 1 week prepartum, 25(OH)D levels tended to be significantly correlated with IL-4 (P = 0.076) and IgG (P = 0.058) levels. No significant correlation was observed between 25(OH)D levels and other measured variables in the first and third weeks after parturition. It should be noted that the amount of 25(OH)D in the first week after calving reaches to its lowest level, which may leads to impaired immune system function and increased susceptibility of dairy cows to disease. [ABSTRACT FROM AUTHOR]

Contents: Endogenous retroviruses (ERVs) are involved in cellular proliferation, pluripotency, tissue‐specific remodelling and regulation of developmental processes. These elements are transcriptionally active in mouse and human pre‐implantation embryos. Empirical evidence indicates that regulatory networks involved with ERV transcripts are responsible for pluripotency and totipotency at certain stages of mouse and human pre‐implantation development. Yet, the expression in pre‐implantation bovine embryo remains unidentified. To determine whether two members of bovine endogenous retroviruses, BERV‐K1 and BERV‐K2, are expressed in the pre‐implantation bovine embryo, each embryonic stage developed in vitro and was subjected to RNA release, reverse transcription and quantitative PCR. We found that BERV‐K1 and BERV‐K2 are expressed throughout different stages of pre‐implantation development. The higher level of expression was detected in embryonic blastomeres with totipotent/pluripotent status (two‐cell to 16‐cell stages), while the more differentiated blastocyst stage showed significantly lower levels of ERVs expression. These findings suggest a possible role for endogenous retroviruses in the establishment of totipotent and pluripotent states in pre‐implantation bovine embryo, similar to functions which have been suggested for these elements in human and mouse embryos. [ABSTRACT FROM AUTHOR]

Populus trichocarpa is an ecologically important tree across western North America. We used a large population sample of 498 accessions over a wide geographical area genotyped with a 34K Populus SNP array to quantify geographical patterns of genetic variation in this species (landscape genomics). We present evidence that three processes contribute to the observed patterns: (1) introgression from the sister species P. balsamifera, (2) isolation by distance (IBD), and (3) natural selection. Introgression was detected only at the margins of the species' distribution. IBD was significant across the sampled area as a whole, but no evidence of restricted gene flow was detected in a core of drainages from southern British Columbia (BC). We identified a large number of FST outliers. Gene Ontology analyses revealed that FST outliers are overrepresented in genes involved in circadian rhythm and response to red/far-red light when the entire dataset is considered, whereas in southern BC heat response genes are overrepresented. We also identified strong correlations between geoclimate variables and allele frequencies at FST outlier loci that provide clues regarding the selective pressures acting at these loci. [ABSTRACT FROM AUTHOR]

Abstract: The objectives of this study were to determine the effects of a pre-partum diet with lower than recommended (DCAD=−82mEq/kg of dietary DM) amounts of anionic salts on metabolism, health, reproductive performance and milk production in dairy cows. Sixty Holstein multiparous cows were enrolled 21days prior to expected calving date. The animals were randomly assigned to receive one of two rations: 30 cows received anionic ration [−82mEq (NA+K−Cl−S)/kg of DM] for 21d to parturition and the other group (n =30) were fed a usual dry period ration (+192mEq/kg of DM). Serum samples obtained at days −21, +3 and +21 relative to calving were analyzed for β-hydroxybutyrate (BHBA), non-esterified fatty acids (NEFA), glucose, calcium (Ca), inorganic phosphorus, magnesium, chloride, sodium, potassium, cholesterol, urea, creatinine, total protein, albumin, and aspartate aminotransferase (AST). Urine pH declined from 8.4 at 21d before calving (pre-treatment) to 6.2 at day 7 pre-partum in the treatment group. Repeated-measure mixed model analysis indicated that the concentrations of Ca were significantly increased and creatinine, and AST were significantly decreased by lowering DCAD. The concentrations of BHBA, NEFA and glucose were not affected by treatment. The incidence of milk fever and culling were 5 and 11 times higher in the control group in comparison with the treatment group, respectively. The intervals from calving to first breeding and to pregnancy were not influenced by treatment. There was no group effect on average daily milk yield or fat percentage. [Copyright &y& Elsevier]

The Saanen goat is one of the highest milk-producing goat breeds and has a high reproductive yield. Twelve pregnant dairy Saanen does were selected to study the variations in energy-related blood metabolites during periparturition and to highlight the negative energy balance (NEB) rate during this critical period. Blood from the jugular vein was collected from each doe on days 29, 14 and 6 before the expected kidding time and also 12 h and on days 7, 13, 19, 21, 28, 35 and 42 postpartum. The concentrations of β-hydroxybutyrate (BHBA), non-esterified fatty acid (NEFA), cholesterol, triglyceride, glucose, total protein, albumin, blood urea nitrogen and aspartate aminotransferase (AST) activity were determined. Since serum metabolites were measured over time, a repeated measures approach using ANOVA with mixed linear models was used. The results of our study indicated that the changes in BHBA concentrations were between 134 and 375 μmol/l. There was a low number of does with BHBA concentrations above 1,000 μmol/l. However, the number of does with abnormal NEFA concentrations (≥0.6 mmol/l) was high. The NEFA results were in agreement with the increased proportion of does with AST concentrations greater than the cutoff level (≥100 U/l). We conclude that similar to dairy cows, NEB occurs in dairy Saanen goats during the periparturition period. NEFA concentration reflected a NEB better than BHBA in dairy Saanen goats. [ABSTRACT FROM AUTHOR]

Abstract: A prospective study involving 18 pregnant ewes of Baloochi breed were conducted to measure the effect of monensin administered 40days pre-lambing on metabolic function pre-parturition and post-parturition. The pregnant ewes were randomly assigned to one of the 4 treatments: 1) were received monensin and fed an ordinary ration, 2) received monensin and fed restricted ration, 3) fed restricted ration without monensin and 4) control group which fed an ordinary ration without monensin administration. Blood was sampled from each sheep at days 60, 45, 30, 20, 15, 10, 5, 1 prior to parturition, and hour 12 and days 1, 2, 3, 4, 7, 13, 19 and 21 postpartum. The BHB concentrations significantly decreased in animals which received monensin and fed a restricted or an ordinary ration in comparison to the group which not received monensin and fed a restricted ration at prepartum period. The sheep which received monensin showed lower concentrations of NEFA in comparison to animals which were not received monensin. There was no significant effect of monensin on energy, protein indicators and electrolytes in postpartum period. However, feed restriction significantly decreased the concentrations of cholesterol, urea, albumin and Mg at post-parturition period. The results of this study indicate that administration of monensin to pregnant ewes during prepartum period had a markedly positive influence on energy indicators in late pregnancy. [ABSTRACT FROM AUTHOR]