Cisto ovariano em vacas de leite: incidência, resposta à aplicação de GnRH e desempenho reprodutivo Ovarian cysts in lactating dairy cows: incidence, response to GnRH, and reproductive performance

A incidência de cistos ovarianos, a resposta ao tratamento com GnRH e os efeitos da ocorrência de cisto no desempenho reprodutivo e na taxa de descarte foram determinados em vacas lactantes da raça Holandesa. Vacas lactantes (n=333) foram avaliadas semanalmente por ultrassonografia a partir da quarta semana pós-parto, visando à detecção de corpos lúteos (CL) e de folículos ovarianos maiores que 10mm. Na sétima semana pós-parto, as vacas foram classificadas: em ciclando (n=248; presença de CL em um dos exames ultrassonográficos); em anestro (n=54; ausência de CL e de folículos >25mm) e com cisto (n=31; ausência de CL e presença de estruturas >25mm), quando foram distribuídas em: grupo-controle (n=16; sem tratamento) e grupo-tratamento (n=15; vacas que receberam uma aplicação de GnRH). A taxa de cura foi de 60,0% no grupo das vacas tratadas e de 87,5% no grupo-controle. As vacas com cistos apresentaram maior intervalo parto-primeira inseminação artificial (P<0,05; 91,4±8,3 vs. 77,8±2,5), maior número de serviços por concepção (P<0,05; 4,4±1,2 vs. 3,6±1,5), maior intervalo parto-concepção (P<0,05; 214,8±25,9 vs. 174,9±7,7) e maior taxa de descarte (P<0,05; 41,2 vs. 21,8%) do que as vacas ciclando. Vacas diagnosticadas com cisto na sétima semana pós-parto apresentaram recuperação espontânea, embora o intervalo parto-concepção e a taxa de descarte tenham sido maiores para essas vacas.<br>The incidence of ovarian cysts, response to GnRH treatment, and effects on reproductive performance and culling rate of Holstein cows were determined. Ovaries of lactating cows (n=333), were weekly monitored by ultrasound, beginning at fourth week postpartum, to determine the presence of corpus luteum (CL) and follicles greater than 10mm. In the seventh week the cows were classified as cycling (n=248; presence of corpus luteum (CL) in one of the ultrasound evaluations); anovulatory (n=54; absence of CL and follicles less than 25mm), and cystic (n=31; absence of CL and presence of structures greater than 25mm). The cysts cows were distributed in two groups in the seventh week: control group (n=16; without treatment) and treatment group (n=15; cows received one GnRH injection). The recovery rate was 60.0% in treated cows and 87.5% in control cows. The cystic cows had longer average interval from parturition to first AI (P<0.05; 91.4±8.3 vs. 77.8±2.5), higher number of services per conception (P<0.05; 4.4±1.2 vs. 3.6±1.5), longer interval parturition to conception (P<0.05; 214.8± 25.9 vs. 174.9±7.7), and higher percentage of culled cows (P<0.05; 41.2% vs. 21.8%), than cycling cows. Cystic cows without treatment had the same recovery rate as cows treated with GnRH. Cystic cows had longer intervals from parturition to conception, and higher culling rate

How much land-based greenhouse gas mitigation can be achieved without compromising food security and environmental goals?

Feeding 9–10 billion people by 2050 and preventing dangerous climate change are two of the greatest challenges facing humanity. Both challenges must be met while reducing the impact of land management on ecosystem services that deliver vital goods and services, and support human health and well-being. Few studies to date have considered the interactions between these challenges. In this study we briefly outline the challenges, review the supply- and demand-side climate mitigation potential available in the Agriculture, Forestry and Other Land Use AFOLU sector and options for delivering food security. We briefly outline some of the synergies and trade-offs afforded by mitigation practices, before presenting an assessment of the mitigation potential possible in the AFOLU sector under possible future scenarios in which demand-side measures codeliver to aid food security. We conclude that while supply-side mitigation measures, such as changes in land management, might either enhance or negatively impact food security, demand-side mitigation measures, such as reduced waste or demand for livestock products, should benefit both food security and greenhouse gas (GHG) mitigation. Demand-side measures offer a greater potential (1.5–15.6 Gt CO2-eq. yr−1) in meeting both challenges than do supply-side measures (1.5–4.3 Gt CO2-eq. yr−1 at carbon prices between 20 and 100 US$ tCO2-eq. yr−1), but given the enormity of challenges, all options need to be considered. Supply-side measures should be implemented immediately, focussing on those that allow the production of more agricultural product per unit of input. For demand-side measures, given the difficulties in their implementation and lag in their effectiveness, policy should be introduced quickly, and should aim to codeliver to other policy agenda, such as improving environmental quality or improving dietary health. These problems facing humanity in the 21st Century are extremely challenging, and policy that addresses multiple objectives is required now more than ever

Role of vitamin B12 on methylmalonyl-CoA mutase activity*

Vitamin B12 is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes, which have been grouped into three subfamilies depending on their cofactors. Among them, methylmalonyl-CoA mutase (MCM) has been extensively studied. This enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the substrate. The crystal structure of MCM determined in Propionibacterium freudenreichii var. shermanii has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme, coenzyme, and substrate. The existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in metabolism. The recent crystallization of the human MCM has shown that despite being similar to the bacterial protein, there are significant differences in the structural organization of the two proteins. Recent studies have identified the involvement of an accessory protein called MMAA, which interacts with MCM to prevent MCM’s inactivation or acts as a chaperone to promote regeneration of inactivated enzyme. The interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase, the impact of mutations at a functional level and their repercussion in the development and progression of MMA in humans. It is still necessary to study the mechanisms involved in more detail using new methods

A saturated map of common genetic variants associated with human height.

Common single-nucleotide polymorphisms (SNPs) are predicted to collectively explain 40-50% of phenotypic variation in human height, but identifying the specific variants and associated regions requires huge sample sizes &lt;sup&gt;1&lt;/sup&gt; . Here, using data from a genome-wide association study of 5.4 million individuals of diverse ancestries, we show that 12,111 independent SNPs that are significantly associated with height account for nearly all of the common SNP-based heritability. These SNPs are clustered within 7,209 non-overlapping genomic segments with a mean size of around 90 kb, covering about 21% of the genome. The density of independent associations varies across the genome and the regions of increased density are enriched for biologically relevant genes. In out-of-sample estimation and prediction, the 12,111 SNPs (or all SNPs in the HapMap 3 panel &lt;sup&gt;2&lt;/sup&gt; ) account for 40% (45%) of phenotypic variance in populations of European ancestry but only around 10-20% (14-24%) in populations of other ancestries. Effect sizes, associated regions and gene prioritization are similar across ancestries, indicating that reduced prediction accuracy is likely to be explained by linkage disequilibrium and differences in allele frequency within associated regions. Finally, we show that the relevant biological pathways are detectable with smaller sample sizes than are needed to implicate causal genes and variants. Overall, this study provides a comprehensive map of specific genomic regions that contain the vast majority of common height-associated variants. Although this map is saturated for populations of European ancestry, further research is needed to achieve equivalent saturation in other ancestries