Resumo em Inglês:

ABSTRACT The objective of this study was to analyze dairy farm characteristics as a function of milk urea nitrogen (MUN) content in the north and west of the state Paraná, Brazil. Milk urea nitrogen serves as an indicator of protein utilization by cows. In view of the high costs of protein in animal diets, this study evaluated farm characteristics that could influence MUN content. For this, 32 dairy farms were randomly selected for application of a questionnaire assessing qualitative and quantitative variables. Interviews and samplings of bulk tank milk were carried out from October 2018 to October 2019. Three clusters of farms were identified: cluster 1, low MUN content (8.07 mg/dL); cluster 2, high MUN content (21.60 mg/dL); and cluster 3, intermediate MUN content (11.90 mg/dL). Clusters 1, 2, and 3 comprised 19, 4, and 9 farms, respectively. No association was found between MUN content and production system (conventional or agroecological). However, clusters differed significantly (P<0.05) in total number of cows and number of lactating cows. Differences (P<0.05) were also found for milk fat and total solids contents. As MUN is highly influenced by diet protein levels and the analyzed farms used feed based on the same ingredients (corn and soybean), it was not possible to identify which factors influenced MUN content for the studied farm groups.

Resumo em Inglês:

ABSTRACT The objective of this work was to analyze the impact of different feeding frequencies on the growth and hematological parameters of freshwater fish species (tambaqui, Colossoma macropomum; matrinxã, Brycon amazonicus) subjected to biofloc technology enriched with sodium chloride. We tested two feeding frequencies: T1 = feeding all experimental days for tambaqui, except on Sundays; T2 = feeding all experimental days for tambaqui, except on Sundays and Wednesdays; M1 = feeding all experimental days for matrinxã, except on Sundays; and M2 = feeding all experimental days for matrinxã, except on Sundays and Wednesdays. The growth performance of tambaqui and matrinxã were not affected by the treatments. The MCHC for matrinxã was the only hematological parameter significantly different. The physiological status (Kn = condition factor) of the M2 treatment was the only parameter that presented a significant difference in relation to the central value (Kn = 1.00). Water quality parameters remained within the range indicated for the rearing of both species. The feeding frequencies tested do not negatively affect tambaqui or matrinxã.

Resumo em Inglês:

ABSTRACT The objective was to describe the organizational structure of the Mangalarga herd and evaluate the influence of geographic distribution and different coats on the population structure and genetic diversity. Genealogic data of horses born between 1919 and 2018 were submitted to the software ENDOG 4.8, corresponding to the total population (TP), and those born between 2009 and 2018, representing the reference population (RP). Wright’s fixation index, inbreeding coefficient (F), and average relatedness (AR) were estimated considering each Brazilian state as a subpopulation and, afterwards, the different coat colors as subpopulations. The origin and use of breeding animals were used as parameters to classify the populations in the different states within the strata: Nucleus, Multiplier, Commercial, and Isolated. Considering Brazilian states as subpopulations, the mean value estimated for FIS in the RP was 0.0091, FIT of 0.0107, FST of 0.0016, F of 5.81%, and AR of 3.81%. In the RP, the sorrel coat accounted for 87.58% of the genetic contribution. Considering different coat colors as subpopulations, the mean value estimated for FIS in the RP was 0.0103, FIT of 0.0107, FST of 0.0004, F of 3.53%, and AR of 3.29%. In the RP, the breed is present in 14 states. Of those, 53.33% were classified as Multiplier herds and 46.67% as Commercial herds. The organizational structure of the Mangalarga breed is not pyramid shaped and, even with the greater genetic contribution of the state of São Paulo and of the sorrel coat, the inbreeding coefficient is under control.

Resumo em Inglês:

ABSTRACT The present study aimed to evaluate the effectiveness of the grain processing carried out by a device containing round and oblong holes attached to the inside of the forage harvester and evaluate its impact on the nutrient composition of corn silage, animal productivity, feeding behavior, apparent digestibility of the diet, and carcass traits of feedlot finished steers. The silages tested were: silage subjected to the grain processor (SGP) and silage not subjected to the grain processor (SNGP), which also made up the diet given to the animals. For animal assessment, we used 32 crossbred steers (half Angus, half Nellore), with an average age of 11±2 months and an initial average body weight of 350±9.06 kg. The experiment was a randomized block design, consisting of two treatments and eight repetitions each, represented by a pen with two animals. The SGP showed a greater accumulation of grains at the bottom of the particle separator system, that is, the processor promoted a reduction in particle size, which led to a 42% higher starch content in the lower layer. At the end of the 112 days of evaluation, the animals that received the diet composed of SGP achieved higher daily weight gain (1.627 kg/day) than those fed SNGP (1.427 kg/day), better feed efficiency, and higher carcass gain during the experimental period (116.3 vs 105.5 kg). The use of the grain processing system improves the use of the diet by the animals and makes a greater fraction of starch available, resulting in higher animal weight gain.

Resumo em Inglês:

ABSTRACT We aimed to evaluate the effects of storage condition (SC) and storage time (ST) on the fermentative parameters and nutritional value of relocated whole-plant corn silage (WPCS) in plastic bags. A completely randomized design was used in a 2 × 5 factorial arrangement, with two SC (in the field without cover and in a barn as covered space) and five ST (10, 30, 60, 90, and 120 d), with four replications. Corn was harvested (321 ± 10.3 g kg−1 dry matter (DM)) and relocated in plastic bags (50 kg) after 210 d of fermentation. The mold count of silage stored in the barn displayed a quadratic adjustment (P = 0.008) and reached its lowest value at 60 d of storage. Yeast count decreased (P = 0.001) linearly as a function of time in the silage stored in the barn. Lactic (P<0.001) and acetic (P<0.001) acid concentrations increased linearly as a function of silage ST in the field. A quadratic relationship was observed between protein concentration (P = 0.039) and in vitro dry matter digestibility (IVDMD; P<0.001) and ST for silage in the field, with the lowest value observed at 90 (58.3 g kg−1 DM) and 60 (529.3 g kg−1 DM) days, respectively. The concentration of ammonia nitrogen increased linearly by 6.80 g kg−1 TN (P<0.001) as a function of ST in relocated silage in the field. The IVDMD increased linearly (P<0.001) as a function of time in silage stored in the barn. Silage in the field had 1.00 log CFU g−1 more lactic acid bacteria (LAB) than those stored in barns. A quadratic adjustment was observed (P<0.05) as a function of ST on LAB count, aerobic stability, maximum temperature, time to reach maximum temperature, DM, and organic matter. It is recommended that silage be stored in bags in the field for use within 60 d. Silage stored in bags in a barn can be used within 120 d.

Resumo em Inglês:

ABSTRACT This study aimed to characterize the response mechanisms and evaluate the resistance of Megathyrsus maximus hybrids to water deficit and waterlogging. The experiment was conducted in a greenhouse using a randomized block design with an 8 × 3 × 2 factorial arrangement. Treatments were a combination of eight genotypes of M. maximus, three water conditions (control, waterlogging, and water deficit), and two harvest times (20 days of water stress and 12 days post-recovery). Productive and morphological traits were evaluated at the end of the stress period and after the recovery period. All hybrids subjected to water deficit showed reduced aerial and root mass. However, a survival response was observed post-stress, with recovery of approximately 28.4% of the aerial part and 16.3% of the root system in all genotypes. Hybrid PM409 showed potential for adaptation to waterlogging, as suggested by the observed greater root production (41.2%) compared with the average production of other genotypes. In addition, there was no reduction on leaf and stem mass production compared with the control condition. The results suggest that no material showed to be resistant to water deficit. On the other hand, hybrid PM409 showed promising traits for waterlogging stress resistance.

Resumo em Inglês:

ABSTRACT We determined the impacts of light intensity, fasting, and storage times on total protein (TP), albumin (ALB), globulin (Glb), uric acid (UA), creatinine (Cre), calcium (Ca), phosphorus (P), and alkaline phosphatase (ALP) in serum and plasma of broilers. At 42 days old, 140 broilers (3,123 ± 654 g) were assigned to two light intensities (5 or 20 lux m−2) and seven fasting times (0, 2, 4, 6, 8, 10, and 12 h). At 45 days old, blood collection was performed in all the broilers. Serum and plasma were stored in a freezer at −20 °C and analyzed on 0, 15, 30, 60, and 120 days. Higher concentrations of Cre and plasma Ca were observed at 20 lux, while the other components were observed at 5 lux. Serum ALB and Ca decreased with each hour of fasting, whereas ALP increased. Uric acid had the lowest concentration at 4 h and 51 min of fasting. Peak serum concentrations of Glb, TP, and Cre were at 6 h, 4 h and 30 min, and 5 h and 15 min of fasting, respectively. Plasma UA, Ca, and P had the lowest concentration at 3 h and 48 min, 5 h and 45 min, and 30 min of fasting, respectively, and a reduction in ALP. Serum UA, TP, and Glb concentrations increased with increasing storage time. Peak serum concentrations of Cre, P, and Ca were at 42, 119, and lowest at 82 days, respectively. Plasma Glb and ALP showed an increase with each storage day, while Cre decreased. Plasma UA and P showed the highest concentrations at 101 and 62 days, respectively. Plasma Ca showed a lower concentration at 50 days. The factors studied significantly influence key blood components in broilers. Higher light intensity increases Cre and Ca concentrations, while fasting reduces serum ALB and Ca, with variable peaks in other components. Storage boosts serum UA, TP, and Glb, with component-specific peaks and declines over time.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the effect of delivery frequency of loose mineral mixtures (LMM) offered to grazing steers on the physicochemical characteristics of the mixture and animal performance. Two experiments were carried out both during the wet-to-dry transition period (March 2021 to June 2021) and during the rainy season (November 2021 to March 2022). Brangus steers (n = 120, distributed in 24 paddocks) were used in experiment 1 and Nellore steers (n = 96, distributed in 20 paddocks) in experiment 2. The LMM contained 8% phosphorus and was delivered at two different frequencies: weekly (DF7d) and every 21 days (DF21d). The paddock was considered the experimental unit, with 12 experimental units in experiment 1 and 10 experimental units in experiment 2. The LMM disappearance was assessed as the difference between LMM delivered mass and orts. Assessments included the chemical characteristics of the LMM orts, the rainfall drained water mineral content and its electrical conductivity, fecal and plasma mineral content, and animal performance. Data were analyzed for outliers and subjected to analyses of maximum restricted likelihood. In experiment 1, drained rainfall water was higher for DF21d. There were differences in plasma and fecal mineral concentrations due to homeostatic balance. There were no significant differences in average daily weight gain (ADG) between treatments during the wet-to-dry transition period (P>0.05); however, the ADG of animals supplemented weekly was 60 g higher than ADG of animals in the DF21d treatment (P<0.04). During the rainy season, there was a greater demand for force to penetrate the mass of the mixture for the DF21d treatment (2.14 vs. 1.63 kg/cm2; P = 0.01). The delivery frequency of loose mineral mixtures changes the physicochemical patterns of the supplement, affecting animal performance, which is more evident during the rainy season.