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This study aimed to evaluate the effects of dietary supplementation of rumen-protected methionine (RPM) on the body temperature and conception rate of Nelore cows exposed to high temperature and humidity index (THI) values. This study was realized on a commercial beef farm located in the north of Brazil (5º 31’ 39” S, 48º 49’ 18” W). At d-31, 31 days before the FTAI protocol, a total of 563 lactating multiparous Nelore cows were divided into two treatments, with three blocks each, the control group (CG) and methionine group (MG). Both groups were kept on tropical pastures and received a mineral supplement. The MG Group was supplemented with 3g RPM/100g during 77 days, and the expected mineral supplement intake of both groups was 100g/cow/day. Between d0 and d9 of the FTAI protocol, a subset of groups of cows (n=142) remained with a data logger attached to the progesterone device, to monitor intravaginal temperature (IT) every 30 min. During the period that the cows remained with the dataloggers the minimum, average, and maximum THI were 72.76, 78.02, and 83.28, respectively. Pregnancy diagnosis was realized 35 days after the artificial insemination and the conception rate was calculated as the number of pregnant cows/inseminated cows. Data were analyzed using the JMP GLIMMIX procedure. RPM supplementation did not affect the conception rate (CG = 64.36% vs. MG = 58.19%, P >0.05). Intravaginal temperature from day 1 to day 8, between 0630 and 2030 h and between 2200 and 0100 h were lower (P≤0.05) for MG in comparison with CG. The average and the maximum IT were, respectively, 38.94ºC, 40.88ºC for MG and 39.02ºC, and 41.38ºC for CG. In conclusion, the supplementation of rumen-protected methionine reduced the internal body temperature in Nelore cows submitted to high THI environments, during the hottest hours of the day, but does not affect the conception rate.

The accumulation of industrial by-products increases the use of sweet potato waste for ruminants, but ruminal pH characteristics are still not well known. The objective was to assess the fluctuation of ruminal pH in sheep supplemented with different levels of sweet potato flour inclusion in their diet. Four rumen-fistulated sheep were used; they were fed a diet based on ryegrass haylage (Lolium multiflorum) and sweet potato flour (Ipomoea batatas), provided according to the level of inclusion in the total diet (0, 0.5, 1.0 and 1.5%). Approximately 80 ml of ruminal fluid was collected for reading on a bench pH meter. Statistical data analysis was run on Statistical Analysis System (SAS Institute INC. Cary, NC, USA), and statistical difference was considered for p < 0.05. The animals that received 1.5% of sweet potato flour in their diet presented acid rumen pH; the 1.0% group presented rumen pH acidification in the first 6 hours after feeding, and the 0.5% level of inclusion did not change the rumen environment. It is concluded that the inclusion of 0.5% sweet potato flour in sheep diet proved to be an efficient energy supplementation strategy. The accumulation of industrial by-products increases the use of sweet potato waste for ruminants, but ruminal pH characteristics are still not well known. The objective was to assess the fluctuation of ruminal pH in sheep supplemented with different levels of sweet potato flour inclusion in their diet. Four rumen-fistulated sheep were used; they were fed a diet based on ryegrass haylage (Lolium multiflorum) and sweet potato flour (Ipomoea batatas), provided according to the level of inclusion in the total diet (0, 0.5, 1.0 and 1.5%). Approximately 80 ml of ruminal fluid was collected for reading on a bench pH meter. Statistical data analysis was run on Statistical Analysis System (SAS Institute INC. Cary, NC, USA), and statistical difference was considered for p < 0.05. The animals that received 1.5% of sweet potato flour in their diet presented acid rumen pH; the 1.0% group presented rumen pH acidification in the first 6 hours after feeding, and the 0.5% level of inclusion did not change the rumen environment. It is concluded that the inclusion of 0.5% sweet potato flour in sheep diet proved to be an efficient energy supplementation strategy.

This study evaluated the effect of different supplements during winter on the performance of heifers in a native Pampa biome field using deferred grazing and evaluated the economic viability of each treatment. A total of 124 heifers from Brangus and Angus breeds, 18 months old, and with an average weight of 301.6 kg were included in this experiment. The treatments applied were: control with only native grassland, native grassland + 80P mineral salt treatment (MS), native grassland + protein salt treatment (PS), and native grassland + protein/energy salt treatment (PES). Besides the productive, botanical, and bromatological characteristics of the pasture, the average daily gain and the live weight gain per hectare were evaluated. The economic viability of the treatments was evaluated through partial budgeting. Weight loss was observed in all treatments. However, only the PES treatment differed from the others, with an average daily gain of -0.046 kg dia-1 (p value < 0.005). The MS treatment was the best regarding economic viability. Despite that, the smallest weight loss was observed in the PES treatment, which may be a determinant in the development and future performance of heifers. Despite the small net margin, this treatment did not incur additional costs to the system.

The spring forage emptiness is an obstacle to the development of Brazilian livestock, including in the Bioma Pampa region. Feed strategies for this period contributed to the development of livestock and to the conservation of the biome. The objective of this work was to know the nutritional potential of forages during spring forage for use as strategies in the forage planning. The experiment had a completely randomized design, with ten forages and four replicates. The chemical composition, in vitro dry matter digestibility (IVDMD) and the total digestible nutrient content (NTD) of elephant grass, brachiaria cultivars Convert and Marandu, Tifton 68; diploid and tetraploid ryegrass; red, white and arrowleaf clover; and bird’s-foot trefoil. The grasses had a higher proportion of fibrous constituents, and lower levels of NDT and DMD, thus, lower nutritional value. Negative correlation between mineral matter and fibrous constituents with CP, TDN and IVDMD, was observed. Forages studied can be used as pasture alternatives for ruminants in the spring forage emptiness of the Pampa, Brazil, however, the strategy of using them should be a pasture planning.

Neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents were evaluated in pressurized and unpressurized conditions using samples of roughage and concentrates. In summary, the samples were dried, processed in a knife mill, weighed in nonwoven bags (100g/m²), placed in a container and treated with neutral or acid detergents. Extractions of NDF and ADF content were carried out in a non-pressurized condition at temperature of 100°C for 60min and in pressurized condition using different temperatures of 100 and 110°C for 60min. Results of the different temperatures using the pressurized procedure were compared to those obtained with the pressurized through the linear regression analysis. The method with the temperature 110°C for 60 min had a high level of agreement. Was not observed a bias potential of proportion (P>0.05). There was not a systematic inclination of the methods to overestimate or underestimate errors. This methodology can be carried out with roughage and concentrate feedstuffs simultaneously.