Sirvi Autor "Ribeiro, A.S." järgi
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Kirje Effect of different fertilization protocols and cutting intensity on marandu grass(Estonian University of Life Sciences, 2025) Ribeiro, A.S.; Pires, A.J.V.; Fries, D.D.; Santos, D.C.; Dutra, I.C.; Oliveira, G.R.S.; Sousa, M.P.; Públio, P.P.P.; Silva, H.S.; Santos, A.P.S.; Amorim, S.S.The present study aimed to investigate the effects of different cutting intensities, combined with different fertilizations, on the productive characteristics, carbohydrate concentration and photosynthetic pigments of Urochloa brizantha cv. Marandu. It was carried out in a completely randomized design in which five fertilization treatments were evaluated: a control treatment without fertilizers and four fertilizer combinations (PK; NP; NK; NPK). The cutting intensities tested were 10 and 20 cm in height. There were four replicates per treatment. Plastic pots of 12 liters were used as experimental units, which were filled with 10 dm³ of soil with a clayey-sandy loam texture. Seeds of Urochloa brizantha cv. Marandu, with 80% of cultural value, were used. There was a significant difference for fertilization with NP and NPK, which resulted in higher production of shoot dry mass (PMSPA), residue dry mass (PMSRE) and root dry mass (PMSRA)in addition to higher concentrations of total soluble sugars in the shoot, residue and root. At a cutting intensity of 20 cm, NK and NPK fertilizations provided the highest levels of chlorophyll a. On the other hand, when analysing chlorophyll b and total chlorophyll at an intensity of 10 cm, NK fertilization presented the highest levels. However, at an intensity of 20 cm, NPK fertilization presented the highest levels of chlorophyll b, carotenoids and total chlorophyll. Regarding starch content, the PK and NPK treatments presented lower values at an intensity of 10 cm, while, at an intensity of 20 cm, NK fertilization resulted in the lowest starch content. Given the results presented, it is concluded that the use of NP fertilization at an intensity of 20 cm is recommended because it provides better indices on photosynthetic pigments, productive characteristics and total soluble sugar contents of Urochloa brizantha cv. Marandu.Kirje Forage potential of six sugarcane cultivars for feeding ruminants(Estonian University of Life Sciences, 2025) Santos, D.C.; Pires, A.J.V.; Ribeiro, A.S.; Andrade, W.R.; Nogueira, M.S.; Dutra, I.C.; Oliveira, G.R.S.; Sousa, M.P.; Santos, W.B.S.; Paixão, T.R.; Silva, H.S.; Amorim, S.S.The study evaluated the productive, morphometric, and bromatological characteristics of six sugarcane cultivars (Regional, RB 865536, RB 867515, CTC2, CTC9001, and CTC9004M). The experiment began at UESB and continued at Fazenda Bela Vista, with evaluations conducted 3 to 18 months after planting. A randomized complete block design was used, with six cultivars per cultivar and four replicates. The cultivar CTC2 presented higher levels of lignin and indigestible neutral detergent fiber, while RB 865536 stood out for its hemicellulose content. The average contents of dry matter, crude protein, ether extract, non-fibrous carbohydrates, and corrected neutral detergent fiber did not differ between cultivars, but there was variation in carbohydrate fractions. CTC9001 presented the highest value for fraction A (68.6%), while cultivar Regional and CTC9004M stood out in fraction B1+B2, and CTC2 and CTC9004M in fractions B3 and C, respectively. In the productive characteristics, CTC9004M presented the highest values of natural matter, dry matter, soluble carbohydrates, production and juice efficiency, standing out in yield. Regarding morphometric characteristics, CTC9001 showed advantages in leaf length and diameter, stem diameter, and leaf area, although there were no significant differences in plant height, tiller number, or leaf number. The cultivars have similar chemical and bromatological composition, agronomic characteristics, and growth behavior. CTC9004M demonstrated superior production efficiency, making it the most suitable option for forage use in semiarid conditions. Future studies should evaluate animal performance directly using these cultivars in feeding trials.Kirje Productive and biochemical responses of Marandu grass under fertilization protocols(Estonian University of Life Sciences, 2025) Dutra, I.C.; Pires, A.J.V.; Jardim, R.R.; Silva, H.S.; Santos, B.E.F.; Silva, N.V.; Ribeiro, A.S.; Dutra, G.C.; Filho, C.A.A.O.; Publio, P.P.P.; Silva, A.P.G.; Nogueira, M.S.The aim of this study was to evaluate the effects of liming and chemical fertilization protocols, containing different combinations of nitrogen (N), phosphorus (P) and potassium (K), on the photosynthetic pigments, productive characteristics and carbohydrate concentration of Urochloa brizantha cv. Marandu. Five fertilization protocols were evaluated (PK fertilizer combination; NP fertilizer combination; NK fertilizer combination; NPK fertilizer combination; and without fertilizer - control), associated or not with soil correction via liming, in a completely randomized design, with four replicates. The experimental units consisted of plastic pots with a capacity of 12 liters, which were filled with 10 dm³ of sandy clay loam soil. Seeds of Urochloa brizantha cv. Marandu, with 80% cultural value were used. With the corrected soil, the NP protocol provided greater production of dry mass of residue (PMSRE), root volume, leaf area, leaf area index, total sugar content (AST) and starch in the root, compared to the other protocols. Without liming, the NP protocol provided greater production of aerial part dry mass (PMSPA), root volume, leaf aerial volume, leaf aerial index and AST content in leaves, roots and residue. The NPK protocol, with liming, was 73% higher in chlorophyll a content, 50% in carotenoid content, 90% in PMSPA, 78% in leaf area and 76.2% in leaf area index, compared to the soil without correction. The use of NP fertilization with liming is recommended as it provides positive responses on the photosynthetic pigments, productive characteristics and total sugar content of Marandu grass.Kirje Productive and feeding performance of dairy cows fed sugarcane bagasse ammoniated with urea and cottonseed(Estonian University of Life Sciences, 2026) Ribeiro, A.S.; Pires, A.J.V.; Santos, D.C.; Albuquerque, M.L.P.; Silva, F.F.; Dutra, I.C.; Amorim, S.S.; Galvao, P.C.S.; Santos, M.L.S.; Amaral, M.V.; Publio, P.P.P.; Oliveira, G.R.S.The objective was to evaluate the use of ammoniated sugarcane bagasse (ASB) and cottonseed (CS) in the diet for lactating cows and their effects on intake, nutrient digestibility, dairy performance, microbial synthesis and ingestive behavior. The experiment was carried out at Bela Vista Farm (Encruzilhada-BA) and at the Forage and Pasture Laboratory of UESB (Itapetinga-BA), using eight multiparous ½ Holstein/Zebu crossbred cows with an average lactation of 20 kg day-1 and body weight of 454.7 ± 23.6 kg. The cows were distributed in two 4×4 Latin squares, in a 2×2 factorial scheme, evaluating ammoniated sugarcane bagasse (30% or 40%) associated or not with cottonseed (0% or 18%). The experiment had four periods of 21 days, 17 of adaptation and 4 of collection, totaling 84 days. The interaction between the proportions of ASB and CS was not significant for any of the variables evaluated. The inclusion of 30% sugarcane bagasse obtained from sugarcane bagasse resulted in higher intakes of dry matter (DM), crude protein (CP), ether extract (EE), non-fibrous carbohydrates (NFC), and total digestible nutrients (TDN), without influencing the consumption of neutral detergent fiber corrected for ash and protein. Higher intake (P < 0.05) of DM, CP, NFC, and TDN was observed in the diet without sugarcane bagasse, and in the diet with sugarcane bagasse, EE intake was higher (P < 0.05). The ASB content and the inclusion of CS influenced digestibility at 40% ASB, and with CS, they provided lower digestibility. Furthermore, individual factors did not affect these variables (P < 0.05). Feed efficiency and percentage of total solids in milk were higher for diets with 40% ASB. The use of 40% ASB with CS is recommended.Kirje Responses of Azospirillum brasilense on Brachiaria brizantha under different soil amendments(Estonian University of Life Sciences, 2025) Publio, P.P.P.; Pires, A.J.V.; Dutra, I.C.; Sousa, M.P.; Figueiredo, G.C.; Nogueira, M.S.; Oliveira, G.R.S.; Ferreira, E.P.L.; Santos, A.F.; Ribeiro, A.S.; Cardoso, P.H.S.; Soares, W.N.The objective of this study was to evaluate the responses of Brachiaria brizantha to inoculation with Azospirillum brasilense in different soil amendments. Four soil amendment treatments were evaluated (Control, liming, combination of NPK fertilizers and liming + combination of NPK fertilizers), associated or not with the inoculant Azospirillum, in a completely randomized design, with five replicates per treatment. The experimental units consisted of plastic pots with a capacity of 12 liters, which were filled with 10 dm³ of sandy clayey loam soil. For soil correction, higher productions were found for the variables SPAD indexes, chlorophyll b content, carotenoids and chlorophyll a/b ratio. The soil correction factor provided greater production of green matter, dry matter, and leaf area index when using liming with NPK when compared to the control treatment. There was an increase in root volume and weight for the type of soil correction. The use of liming and combination of NPK fertilizers promoted greater development of plant height, tiller density, stem and leaf elongation, quantity and average final leaf size. The use of Azospirillum brasilense inoculation associated with soil correction is recommended, as it provides positive responses on the production of the aerial part and roots of Brachiaria brizantha.Kirje TMR silage with sugarcane bagasse and urea: effects on intake, digestibility, and feeding behavior in dairy heifers(Estonian University of Life Sciences, 2026) Santos, D.C.; Pires, A.J.V.; Silva, F.F.; Ribeiro, A.S.; Andrade, W.R.; Albuquerque, M.L.; Dutra, I.C.; Oliveira, G.R.S.; Sousa, M.P.; Mendes, R.B.; Santos, M.L.S.; Amaral, M.V.This study evaluated the effects of total mixed ration (TMR) silage containing two levels of sugarcane bagasse (40% and 50% of dry matter), with or without urea inclusion (2.5%), on intake, nutrient digestibility, nitrogen balance, microbial protein synthesis, and feeding behavior of dairy heifers. Eight crossbred heifers were assigned to two simultaneous 4×4 Latin squares in a 2×2 factorial arrangement. Urea inclusion reduced (P < 0.05) dry matter and neutral detergent fiber intake but improved dry matter and crude protein digestibility. Increasing bagasse level to 50% reduced (P < 0.05) intake and digestibility of nutrients, reflecting the higher fiber content and lower energy density of the diets. Nitrogen balance and microbial protein synthesis were not affected by treatments. Higher bagasse levels increased rumination time per unit of NDF and the number of ruminal boli, indicating greater physical demand for fiber processing. Overall, TMR silage containing 40% sugarcane bagasse without urea provided the best balance between intake and nutrient utilization. These results highlight the importance of optimizing fiber levels and nitrogen sources in TMR silage to improve efficiency in dairy heifer feeding systems under tropical conditions.