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PUPILOMETRIA COMO INDICADOR NÃO INVASIVO DE ESTRESSE TÉRMICO EM OVELHAS

Fri, 29 May 2026 00:00:00 GMT

Título: PUPILOMETRIA COMO INDICADOR NÃO INVASIVO DE ESTRESSE TÉRMICO EM OVELHAS Autor: MARINHO FILHO, Lourdivaldo dos Santos Primeiro orientador: MACHADO, Nitalo André Farias Abstract: The aim of this study was to evaluate pupillometry as a technique for detecting heat stress in sheep under controlled environmental conditions. Six crossbred Santa Inês × Dorper ewes, approximately 7 months old and with an initial body weight of 23.70 ± 5.73 kg (mean ± SD), were assigned to a completely randomized design with repeated measures and exposed to three controlled air temperature conditions (26, 29, and 34 °C; 65% relative humidity) in a climatic chamber under standardized lighting. Pupillary area (PA) was obtained from video recordings by extracting images and processing them manually for analysis. Thermoregulatory responses, including respiratory rate (RR), heart rate (HR), and cortisol, among others, were also evaluated. Means were compared using Tukey’s test, and associations were assessed using Pearson’s correlation (P ≤ 0.05). PA increased by 16.05 mm² (≈20%) between 26 and 34 °C. RR and HR increased progressively across 26, 29, and 34 °C (P < 0.001), while cortisol increased by approximately 66% (P = 0.01). Strong positive correlations were observed between PA and RR (r = 0.88), HR (r = 0.87), and cortisol (r = 0.84). In conclusion, pupillary dynamics are associated with thermoregulatory responses in ewes exposed to heat stress, highlighting the potential of pupillometry in production animals. However, further research is needed to develop technological solutions that enable practical on-farm applications. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Silício e bactérias fixadoras de nitrogênio na qualidade de silagens de milho com e sem espiga

Fri, 31 Oct 2025 00:00:00 GMT

Título: Silício e bactérias fixadoras de nitrogênio na qualidade de silagens de milho com e sem espiga Autor: OLIVEIRA, Jéssica Maria de Sousa Primeiro orientador: FERREIRA, Daniele de Jesus Abstract: This study aimed to evaluate the effects of inoculation with Azospirillum brasilense and the application of different silicon doses on the chemical composition, macro and micromineral composition, microbial population, fermentation profile, and aerobic stability of corn silages, with and without cobs. In the first chapter related to corn silage without cobs, the average contents of nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, and sodium showed no significant differences (P > 0.05) in any of the specific factors. The nitrogen content ranged from 1.57 to 1.62 g kg−1 between treatments with and without inoculation. For microbiology, the average counts of lactic acid bacteria (LAB) were 0.976 and 2.093 log10 CFU g−1 for silages without and with A. brasilense, respectively, with no significant effect (P = 0.171). Filamentous fungi (MOLD) counts ranged from 3,318 to 3,143 log10 CFU g−1 (P = 0.651) and yeast counts from 0.773 to 1,128 log10 CFU g−1 (P = 0.160). There was no interaction between silicon and inoculant (P > 0.05). Gas and effluent losses were reduced, and aerobic stability was maintained for over 120 hours. In the second chapter, concerning corn cob silage, a positive influence of inoculation with A. brasilense and increasing silicon doses on the fermentation profile and chemical composition was observed. Dry matter (DM) contents ranged from 45.3% to 48.7% (P = 0.041), with an increasing trend at higher silicon doses. Inoculation reduced N-NH3/TN levels, reducing protein release (P = 0.038). Fermentation losses were significantly lower (P < 0.05) in silages with inoculant and with 8 kg ha−1 of silicon, reflecting better dry matter conservation and lower effluent production. Aerobic stability showed a significant increase, exceeding 140 h for the combined treatments, while treatments without inoculant or without silicon reached only approximately 96 h before a 2 °C increase in silage temperature. The relationship between higher dry matter and lower fermentable substrate loss suggests that silicon contributed to the structural integrity of the grains and reduced undesirable microbial activity, while A. brasilense favored the rapid colonization by lactic acid bacteria and a consequent drop in pH. This synergy resulted in greater aerobic stability and maintenance of nutritional quality after silo opening. Overall, it can be concluded that the combination of silicon and A. brasilense is an efficient strategy for improving the improvement and conservation of corn silages, especially in the ear fraction, promoting increased dry matter, reduced losses, and greater aerobic stability, without compromising the nutritional value of the forage. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Desempenho produtivo de ovinos alimentados com dieta contendo farelo da vagem de faveira em substituição total ao volumoso

Wed, 29 Oct 2025 00:00:00 GMT

Título: Desempenho produtivo de ovinos alimentados com dieta contendo farelo da vagem de faveira em substituição total ao volumoso Autor: BRITO, Eluiane Souza de Primeiro orientador: PARENTE, Henrique Nunes Abstract: Sheep farming for meat production in the Northeast region of Brazil is based on low-intensive systems, with still low productivity and advanced age at slaughter, resulting in lower financial returns for producers. Therefore, improvements and technological investments in production systems are necessary. In this context, this study aimed to evaluate the productive performance of sheep fed a diet containing bean pod meal as a total replacement for Tifton-85 hay. Fourteen castrated male Santa Inês crossbred sheep, with an average initial weight of 21 ± 2.4 kg and approximately five months of age, were used. They were housed in individual 1.45 m² metal pens. Two diets were evaluated: SVF (without bean pod meal) and CVF (with bean pod meal as a total replacement for Tifton-85 hay), formulated for a daily weight gain of 200 g. The experiment lasted 60 days, with 10 days for animal adaptation to the diets and facilities and 50 days for data collection (confinement). The animals received a diet with a roughage:concentrate ratio of 30/70. The experimental design was completely randomized, with two treatments and seven replicates, with initial weight used as a covariate. Analysis of variance was performed, and when there was an effect, it was considered statistically different. The results showed that providing the diet with bean pod meal as a substitute for hay reduced dry matter intake (P=0.001), crude protein intake (P=0.004), and organic matter intake (P=0.021), but did not affect (P>0.05) the intake of other nutrients. No effect (P>0.05) was observed for the variables weight gain, feed conversion, and biometrics (body length), with average values of 195 g/d, 3.37, and 88.09 cm, respectively. An effect with higher water intake (P=0.048) was observed for the SVF diet (3.65 l/d) compared to the CVF diet (2.77 l/d). The CVF diet showed a better economic response, with a net benefit of 935.37 and a rate of return of 250.01. Due to the results presented above, it is recommended to completely replace roughage with broad bean pod meal in the diet of feedlot sheep. Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação

Utilização de polímeros retentores de umidade no solo sobre o déficit hídrico e avaliação da qualidade de silagens de milho e sorgo produzidas na forma convencional e como silagem de ração total

Fri, 31 Oct 2025 00:00:00 GMT

Título: Utilização de polímeros retentores de umidade no solo sobre o déficit hídrico e avaliação da qualidade de silagens de milho e sorgo produzidas na forma convencional e como silagem de ração total Autor: RODRIGUES, Leonardo Rocha Primeiro orientador: ZANINE, Anderson de Moura Abstract: Corn and sorghum are grasses of high nutritional value, traditionally used as forage for ruminants. However, their cultivation faces challenges in regions with irregular rainfall and long dry periods, which limit grain and biomass production throughout the year. In this context, strategies such as the application of soil moisture-retaining polymer (MRP) and the use of total mixed ration (TMR) silage ensure a continuous supply of quality and sufficient food for these animals, even during the agricultural off- season. The objective of this study was to evaluate the effect of applying an MRP to the soil on water deficit and the quality of corn and sorghum silages, produced in conventional (CS) and total mixed ration forms. The experiment was conducted in a 4 × 2 × 2 factorial design, consisting of four hydration intervals with MRP: control (no hydration), hydration only on planting day (H0), hydration every five days (H5), and hydration every ten days (H10), two crops (corn and sorghum), and two types of silage (CS and TMR). The experimental design used was randomized blocks, totaling 16 treatments and 64 experimental subunits. The fermentative profile (pH, buffering capacity (BC), ammoniacal nitrogen (N-NH3), and soluble carbohydrates (CHOs)), effluent losses (EL), and gas losses (GL), dry matter recovery (DMR), aerobic stability, and bromatological composition were evaluated. There was an interaction effect between the factors for the CHOs variable (P= 0.0233), with the highest mean obtained with the use of sorghum, associated with the use of CS and hydration with MRP every 10 days. Regarding isolated effects, there was a difference between treatments (P<0.05) for crop type and silage type for variables related to fermentative quality. Sorghum silage showed lower pH (3.86) and higher BC (0.1050 mg NaOH/g DM) compared to corn. The use of TMR provided higher pH (4.04), higher BC, and higher N-NH3. Regarding losses, TMR stood out for presenting lower EL and GL and higher DMR, compared to CS. For MRP, there was a difference for N-NH3 and EL variables. The lowest levels of N-NH3 and EL were observed with the use of MRP every 10 days of hydration. As for the bromatological composition, corn silage showed lower NDF levels (41.31%) compared to sorghum (52.81%). TMR showed higher levels of DM, Ash, and CP, while CS showed higher levels of EE, NDF, and ADF. The application of MRP to the soil promoted an increase in the total biomass production of corn and sorghum crops, with the hydration interval every 10 days being the most indicated for higher yields. Sorghum stood out for higher effective degradability (ED) and biomass production, being more efficient than corn, whose silage deteriorates more quickly. Therefore, the use of sorghum with ten days of hydration and retention time (SRT) is recommended for better nutritional value and diet utilization Instituição: Universidade Federal do Maranhão Tipo do documento: Dissertação