DSpace Coleção:

Morphogenesis, structure, and tillering dynamics of tanzania grass under nitrogen fertilization in the Amazon Region

Mon, 01 Jan 2024 00:00:00 GMT

Título: Morphogenesis, structure, and tillering dynamics of tanzania grass under nitrogen fertilization in the Amazon Region Autor(es): CÂNDIDO, Ebson Pereira; LAGE FILHO, Nauara Moura; SANTOS, Airton da Conceição dos; SILVA, Suianne Lorena da Silva e; OLIVEIRA, João Victor Costa de; MACEDO, Vitor Hugo Maués; CUNHA, Antônio Marcos Quadros; RÊGO, Aníbal Coutinho do Abstract: Nitrogen fertilization is one of the main management strategies for continuous pasture management with high productivity. We examined the effects of nitrogen fertilization on the mor phogenic, structural, and tillering dynamic characteristics of Tanzania grass in the Amazon region in the state of Pará, Brazil. The study was conducted using a randomized block design with six treatments (0, 100, 200, 300, 400, and 500 kg N ha−1 year−1 ) and five replicates. The treatments were performed during the rainy season in 2016 and 2017 using urea as the nitrogen source. The leaf elongation rate was increased by 68.5% compared with that of the control treatment (p < 0.01). The leaf appearance rate and number of alive leaves increased with higher doses of nitrogen (p < 0.01, each). The regrowth period was reduced by approximately 13 days under 500 kg N ha−1 (p < 0.01), thus providing more production cycles. Nitrogen fertilization was also associated with a higher tillering rate (p < 0.01); however, the rate of this increase decreased with increasing nitrogen dose. Higher nitrogen doses thus improved the development of Tanzania grass; however, this became less pronounced at doses < 300 kg N ha−1 .

Nitrogen fertilisation as a strategy for intensifying production and improving the quality of Massai grass grown in a humid tropical climate

Sat, 01 Jan 2022 00:00:00 GMT

Título: Nitrogen fertilisation as a strategy for intensifying production and improving the quality of Massai grass grown in a humid tropical climate Autor(es): CÂNDIDO, Ebson Pereira; CUNHA, Antonio Marcos Quadros; MACEDO, Vitor Hugo Maués; OLIVEIRA, Joelma Kyone Silva de; MELO, Deyvid de Menezes; DOMINGUES, Felipe Nogueira; FATURI, Cristian; RÊGO, Aníbal Coutinho do Abstract: The use of nitrogen fertilizers intensifies forage production, especially in tropical climates. This study aimed to evaluate the effects of nitrogen fertil ization on the quantitative and qualitative characteristics of Massai grass grown in a humid tropical climate, specifically Am-type. A completely randomized design was used with six treatments and five replicates. The treatments used were a control treatment (without nitrogen application) and five doses of nitrogen fertilization (100, 200, 300, 400, and 500 kg N ha 1 year 1 ). Urea was used as the nitrogen fertilizer for six applications, with an interval of 30 days. The leaf elongation rate increased by 69.1% at a dose of 500 kg N ha 1 compared to that of the control. The leaf appear ance rate and green leaves per tiller increased with nitrogen fertilization. Nitrogen fertilization did not affect the percentage of leaf blades and dead tissue. The average height of the canopies was 44.0 cm, regardless of fertil ization. There was a quadratic response in total forage accumulation (TFA), with a maximum of 19,136 kg dry matter at a dose of 391 kg N ha 1 year 1 . Nitrogen utilization efficiency was the same as that of TFA. There was a reduction in the recovery of applied nitrogen and the agronomic efficiency of applied nitrogen with nitrogen fertilization. The number of cuts increased linearly with nitrogen fertilization, from 3.2 to 7.5 cuts. Crude protein content increased with nitrogen fertilization. Therefore, nitrogen fertilization favored the productivity and quality of Massai grass grown in a humid tropical climate.

Risk factors associated with the bovine subclinical mastitis in an Amazon micro‑region

Sat, 01 Jan 2022 00:00:00 GMT

Título: Risk factors associated with the bovine subclinical mastitis in an Amazon micro‑region Autor(es): CÂNDIDO, Ebson Pereira; VEIRA, Romero Kadran Rodrigues; RODRIGUES, Marcos ; SANTOS, Patrícia Kaline da Silva; MEDEIROS, Natalia Bianca Caires; RODRIGUES, Marilia Danyelle Nunes Abstract: In this study, we evaluated the main risk factors for the occurrence of bovine mastitis, in the southeastern of Pará, in the Brazilian Amazon. We surveyed 91 dairy farmers to identify management practices and bovine breed characteristics. From each farm, 50 mL of milk sample was collected for microbiological analysis and somatic cell count (SCC). Depending on the management practices and breed, a logit model was used to determine the odds ratio of subclinical mastitis (SCM) occurrence. In irrigated pastures, an SCM-associated risk factor, the occurrence of SCM was 5.03 times higher than that in the non-irrigated pastures. Similarly, in Girolando breed herds, the occurrence of SCM increased by 5.8 times compared to the crossbred herds. Moreover, the occurrence of mastitis was 33 times higher in farms using common cloths for drying teats than in farms using paper towels. Therefore, adoption of better management practices can lead to SCC reduction, milk quality improvement and a guarantee to contain SCC within prescribed Brazilian limits for the Amazon region.

The effects of implementing management practices on somatic cell count levels in bovine milk

Fri, 01 Jan 2021 00:00:00 GMT

Título: The effects of implementing management practices on somatic cell count levels in bovine milk Autor(es): CÂNDIDO, Ebson Pereira; VIEIRA, Romero Kadran Rodrigues; RODRIGUES, Marcos; SANTOS, Patrícia Kaline da Silva; MEDEIROS, Natalia Bianca Caires; RODRIGUES, Marília Danyelle Nunes Abstract: Somatic cell count (SCC) can be used as a proxy for the prevalence of mastitis in a herd, reflecting the hygiene conditions and management practices on dairy farms, and thus an indicator of milk quality. In this study, we in vestigated how the adoption of management practices in milking systems can contribute to the reduction of SCClevels and improve milk quality. We collected data regarding management practices from 91 dairy farms in threemunicipalities of southeastern Pará: Parauapebas, Curionópolis, and Eldorado dos Carajás. Fifty milliliters of milkfrom each farm were collected in bottles containing bronopol, to preserve SCC. An exploratory factorial analysis (EFA) was performed to reduce the number of variables (management techniques) on dairy farms to some latent factors. We then used the selected factors to estimate the bovine mastitis management index to classify farms ac cording to their use of technology and management techniques. Our results showed that most of the farmers (65.9%) used management techniques inefficiently in their systems, resulting in a significant loss of product qual ity, while only 3.3% had adopted the full set of techniques. The EFA results demonstrated that simple manage ment practices including regular cleaning of the milking lines, a strip cup test, the California mastitis test, and washing teats with water before milking could be adopted to improve milk quality. However, in scenarios where the regulations become more rigorous, most farmers are unable to meet the maximum allowable SCC re quirements, necessitating management innovations to reduce SCC. Therefore, the dissemination of knowledge,technical assistance, and access to new technologies is essential for improving management practices, and thus milk quality.