Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage

Citation: Batista, E. D., Detmann, E., Titgemeyer, E. C., Valadares, S. C., Valadares, R. F. D., Prates, L. L., . . . Paulino, M. F. (2016). Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage. Journal of Animal Science, 94(1), 201-216. doi:10.2527/jas2015-9493Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers (Bos indicus) consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 +/- 9 kg) were used in a 5 x 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [(NN)-N-15-N-15]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected (P >= 0.37) by supplementation, but supplementation did increase ruminal NDF digestion (P < 0.01). Total N intake (by design) and N retention increased (P < 0.001) with supplementation and also linearly increased with RUP provision. Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation (P < 0.001). Supplementation with RUP linearly increased (P = 0.02) urea entry rate and tended (P = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended (P = 0.07) to be increased by supplementation, and RUP provision also tended (P = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater (P < 0.001) for control (22%) than for supplemented (9%) heifers. Urinary 3-methylhistidine: creatinine of control heifers was more than double that of supplemented heifers (P < 0.001). Control heifers reabsorbed a greater (P < 0.001) fraction of urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis

Cobertura vegetal e uso da terra nos solos arenosos das áreas de afloramento do Sistema Aquífero Urucuia-Brasil.

O Sistema Aquífero Urucuia (SAU) é um reservatório subterrâneo de água doce que contribui significativamente para a manutenção das vazões do Rio São Francisco e seus afluentes. Situa-se em uma área do Bioma Cerrado considerada como a nova ?fronteira agrícola nacional?, onde ocorrem vários meses anuais de estiagem, e a presença de água subterrânea tem estimulado o uso desta para suprir a crescente demanda na região, principalmente para a irrigação de culturas agrícolas produzidas com altos níveis tecnológicos. O solo influencia na manutenção da qualidade e da quantidade das águas subterrâneas, pelo que é necessária a proteção das áreas de recarga de aquíferos, evitando contaminação decorrente da ocupação com atividades antrópicas, bem como o comprometimento de sua recarga. Este trabalho analisou características da cobertura vegetal e uso da terra nos solos arenosos das áreas de afloramento do Sistema Aquífero Urucuia, contribuindo para a identificação de áreas com maior vulnerabilidade ambiental e potencial de contaminação de águas subterrâneas deste sistema. Solos arenosos representam 45,33% das áreas de afloramento do SAU. De acordo com o Projeto MapBiomas, em 2018, 93,08% dos solos arenosos do SAU apresentavam cobertura vegetal de origem natural: 46,30% com ?Formação savânica?, 42,11% com campo natural e 4,61% com ?Cerradão?. Também havia categorias de uso antrópico: 212.138 ha dos solos arenosos com culturas agrícolas, 145.256 ha com pastagem plantada, 8.284 ha com florestas plantadas, 311 ha com infraestrutura urbana e 1,31 ha com mineração. Nesta região, 84,77% da área do SAU situada em Unidades de Conservação (UCs) de proteção integral e 59,25% da situada em UCs de Uso Sustentável apresenta solos arenosos. De uma forma geral, nestas UCs predomina cobertura vegetal natural, mas há áreas de solos arenosos dentro de UCs de Proteção Integral com atividades de origem antrópica, ao contrário do que é estabelecido para esta categoria de UC no Sistema Nacional de Unidades de Conservação ? SNUC. Assim, a área relativa de solos arenosos do SAU com uso antrópico direto é de praticamente 400 mil ha (399.264 ha) de um total de 5.768.983 ha, sendo importante a adoção de práticas conservacionistas sustentáveis nessa região. Adicionalmente, a efetiva proteção de áreas situadas em unidades de conservação demanda a regularização fundiária, bem como estímulos econômicos e fiscalização ambiental efetiva, num momento em que há incentivos nacionais de expansão das áreas agrícolas e tendência de aumento da demanda pelo uso de água de qualidade na região.ODS-6

Anatomy and tectonic significance of WNW-ESE and NE-SW lineaments at a transpressive plate boundary (Nubia-Iberia)

Recent mapping of the Gulf of Cadiz seafloor permitted to identify major tectonic lineaments: the SWIM lineaments (Zitellini et al., 2009) and Cadiz lineament, striking WNW-ESE and NE-SW, respectively. Multibeam swath bathymetry and interpretation of multi-channel seismic data indicate that these features can be interpreted to correspond to the seafloor morphological expression of active dextral strike-slip faults. Based on the interpreted data and recently published GPS plate kinematic velocity vectors of Nubia with respect to Iberia and the Alboran block (e.g. Fernandes et al.; 2003 Stich et al., 2006) we propose that the SWIM Faults are related to the general NW-SE convergence of Nubia with respect to Iberia, and the Cadiz fault is related to the westward movement of the Gibraltar orogenic arc

Quantum normal-to-inhomogeneous superconductor phase transition in nearly two-dimensional metals

In multi-band systems, electrons from different orbitals coexist at the Fermi surface. An attractive interaction among these quasi-particles gives rise to inter-band or hybrid pairs which eventually condense in a superconducting state. These quasi-particles have a natural mismatch of their Fermi wave-vectors, $\delta k_F$, which depends on the strength of the hybridization between their orbitals. The existence of this natural scale suggests the possibility of inhomogeneous superconducting ground states in these systems, even in the absence of an applied magnetic field. Furthermore, since hybridization $V$ depends on pressure, this provides an external parameter to control the wave-vectors mismatch at the Fermi surface. In this work, we study the phase diagram of a two-dimensional, two-band metal with inter-band pairing. We show that as the mismatch between the Fermi wave-vectors of the two hybrid bands is reduced, the system presents a normal-to-inhomogeneous superconductor quantum phase transition at a critical value of the hybridization $V_c=\Delta_0$. The superconducting ground state for $V<V_c$ is characterized by a wave-vector with magnitude $|\mathbf{q}_c|=q_c=2 \Delta_0/\bar{v}_f$. Here $\Delta_0$ is the superconducting gap in the homogeneous state and $\bar{v}_f$ the average Fermi velocity. We discuss the nature of the quantum critical point (QCP) at $V_c$ and obtain the associated quantum critical exponents.Comment: 6 pages, 4 figure

Monomorphic subtelomeric DNA in the filamentous fungus, Metarhizium anisopliae, contains a RecQ helicase-like gene.

In most filamentous fungi, telomere-associated sequences (TASs) are polymorphic, and the presence of restriction fragment length polymorphisms (RFLPs) may permit the number of chromosome ends to be estimated from the number of telomeric bands obtained by restriction digestion. Here, we describe strains of Metarhizium, Gliocladium and Paecilomyces species in which only one or a few telomeric bands of unequal intensity are detectable by Southern hybridization, indicating that interchromosomal TAS exchange occurs. We also studied an anomalous strain of Metarhizium anisopliae, which produces polymorphic telomeric bands larger than 8 kb upon digestion of genomic DNA with XhoI. In this case, the first XhoI site in from the chromosome end must lie beyond the presumed monomorphic region. Cloned telomeres from this strain comprise 18?26 TTAGGG repeats, followed at the internal end of the telomere tract by five repeats of the telomere-like sequence TAAACGCTGG. An 8.1-kb TAS clone also contains a gene for a RecQ-like helicase, designated TAH1, suggesting that this TAS is analogous to the Y elements in yeast and the subtelomeric helicase ORFs of Ustilago maydis (UTASRecQ) and Magnaporthe grisea (TLH1). The TAS in the anomalous strain of M. anisopliae, however, appears distinct from these in that it is found at most telomeres and its predicted protein product possesses a significantly longer N-terminal region in comparison to the M. grisea and U. maydis helicases. Hybridization analyses showed that TAH1 homologues are present in all other anomalous M. anisopliae strains studied, as well as in some other polymorphic strains, where the recQ-like gene also appears to be telomere-associated.Published online: 2 June 2005

Mudanças climáticas em Sete Lagoas-MG, Brasil: tendências de variações de temperatura e precipitação entre 1926 e 2021.

O aquecimento global e os efeitos relacionados a esse fenômeno representam uma preocupação para a tomada de decisões na agropecuária e outras atividades dependentes do clima. Este trabalho objetiva identificar possíveis tendências de mudanças climáticas de temperatura e precipitação pluvial ou pluviométrica, considerando período de análise de mais de 90 anos consecutivos, na Estação Meteorológica de Sete Lagoas, Minas Gerais. As análises de tendência de mudança de temperatura e dos padrões de precipitação foram realizadas através do ajuste de regressão linear simples. Foram analisadas possíveis tendências de mudanças nos padrões de temperatura e precipitação nas últimas décadas considerando série histórica de dados registrados na Estação Meteorológica de Sete Lagoas entre 1926 e 2021. Foi constatado aumento médio significativo (para 5%) de 1,85 °C na temperatura média, de 1,78 °C na média das máximas, de 1,72 °C na média das mínimas, de 2,38 °C nas máximas absolutas e de 2,19 °C nas mínimas absolutas, enquanto a temperatura média global aumentou em torno de 0,5 °C no último século. As maiores tendências de aumento médio mensal das temperaturas foram observadas principalmente em meses de inverno. Apesar da considerável variação interanual, durante o período também foi observado incremento médio de 35,45 mm de precipitação, concentração das chuvas num período seis dias menor, diminuição de sete dias com volumes precipitados entre 1 mm e 10 mm, preferenciais para a agricultura, e aumento da ocorrência de eventos extremos representados pela incidência de dias com chuvas de maior magnitude. A identificação de tendências locais de mudanças climáticas poderá subsidiar políticas públicas e contribuir para o desenvolvimento sustentável da região, visando minimizar riscos associados às incertezas climáticas e auxiliando no planejamento das atividades agropecuárias, turísticas e outras, podendo adicionalmente representar um documento de referência para estudos de variabilidades e mudanças climáticas globais.bitstream/item/224553/1/Bol-226-Mudancas-climaticas-em-Sete-Lagoas.pd

Impacts of reduction of phosphorus in finishing diets for Holstein×Zebu steers

In Brazil, commonly males of dairy herd are destined to beef production. However, little is known about the mineral requirements for dairy males. Therefore, the objective of this experiment was to evaluate the calcium (Ca) requirements of Holstein×Zebu steers by determining Ca body tissue concentrations, true absorption and retention coefficients, as well as the requirements for maintenance and weight gain of steers fed diets containing or not containing dicalcium phosphate. Twenty-eight Holstein×Zebu steers with an average initial body weight of 377.5±49.4 kg were utilized. The experiment was conducted as a completely randomized design with a 2×2 factorial arrangement of treatments. Factors included 1) two concentrate levels (30% or 60%); and 2) two levels of dicalcium phosphate (DP), 0 or the amount necessary to attend the estimated dietary requirements. Absorption and retention coefficients, maintenance and gain requirements were estimated. The feedstuffs, refusals, feces, urine, blood and bone were sampled for Ca and phosphorus (P) analysis. Phosphorus intake was improved by the addition of concentrate and presence of DP. There were no variations in the daily fecal and urinary phosphorus excretion as a function of DP. The serum level of inorganic phosphorus was lower in non-supplemented animals, although it was within adequate concentrations for all treatments. Dry matter and organic matter intake, organic matter digestibility, performance, and efficiency were not affected by treatment. Absorption and retention coefficients, and the net requirements for maintenance are similar across treatments. Therefore, the lack of inorganic supplementary Ca and P in diets of feedlot finishing cattle does not change the concentrations of these minerals in bone. The dietary requirements of calcium and phosphorus obtained for cattle were lower than those described by the nutritional requirement systems from Brazil, USA, and UK