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.

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.

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.

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.

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.

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.

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.

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.

ABSTRACT This study was conducted to determine the effects of adding pomegranate peel and oregano pulp at different levels (2, 4, 6, and 8%) on a dry matter basis to sheep rations on methane production and rumen fermentation using the in vitro gas production technique. In the study, nine experimental groups were formed by adding different levels (2, 4, 6, and 8%) of pomegranate peel and oregano pulp to the total ration mixture (control ration). Each treatment group was designed with four replications. Rumen fluid was taken from two sheep that were fed mainly roughage. For each feed treatment, four gas production syringes were used. A trial design was created using a total of 40 gas production syringes, and four gas production syringes for blank samples. The prepared syringes were incubated for 24 h. The additive levels of pomegranate peel and oregano pulp did not change total gas, methane (%), and methane (mL) production compared with the control treatment. The use of pomegranate peel and oregano pulp for in vitro rations significantly reduced rumen fluid volatile fatty acid (VFA) levels, except for 2% pomegranate peel. In vitro organic matter digestibility and metabolizable energy levels of both additives were similar to the control ration. In the study, the addition of pomegranate peel and oregano pulp to total ration mixture at 2, 4, 6, and 8% levels did not change total gas and methane production. Except for the addition of 2% pomegranate peel, the treatments suppressed rumen fluid VFA. Besides, it is thought that the additives used in the study can be used up to 2% in the rations of ruminant animals in regions where they may create waste to reduce feed costs.

ABSTRACT The objective of this study was to characterize the sexual development of 48 Nelore bulls by associating the findings of sperm analyses with growth traits and ultrasound-measured testicular traits. Bulls were evaluated from 14.3 to 24.6 months old at intervals of 28 days, totaling 12 observations per animal. Data were subjected to repeated-measures analyses of variance over time (PROC MIXED, SAS 9.2) and equations for semen traits were developed using stepwise regression (PROC REG, SAS 9.2). Regarding the growth performance on pasture, there was an increase in average body weight (388 to 500±4.59 kg), body condition (5-6), and hip height (139 to 145±0.52 cm) with increasing age. However, a lower average daily gain (0.64 to 0.29±0.05 kg) was observed during the dry season. Reproductive traits such as scrotal circumference (27 to 33.6±0.34 cm), testicular artery diameter (2.14 to 2.96±0.04 mm), blood testosterone concentration (8.3 to 22.7±1.48 mg/mL), sperm motility (total: 42 to 82.8±2.91% and progressive: 26.2 to 62.3±2.61%), percentage of rapid cells (38.1 to 79.8±2.9%), and sperm concentration (43.6 to 645±42.1 × 106/mL) increased with increasing age, while there was a reduction in sperm defects (major: 59.4 to 9.6±3.18% and total: 62.5 to 15.1±2.94%). Ultrasonography and growth traits have a moderate power to predict major and total sperm defects but cannot predict other seminal traits. By 19-20 months of age, Nelore bulls start to exhibit reproductive traits that indicate the attainment of sexual maturity.

ABSTRACT The objective of this study was to evaluate the use of grazing management strategies (GMS) in rotational stocking to improve the canopy structure in mixed pastures of Marandu palisadegrass (Brachiaria brizantha cv. Marandu) and legume Macrotyloma axillare. Treatments consisted of combinations of defoliation frequencies (pre-grazing heights of 30 and 40 cm) and intensities (post-grazing heights of 15 and 20 cm) in a 2 × 2 factorial arrangement, corresponding to four GMS: 30-15, 30-20, 40-15, and 40-20 cm, allocated to 16 experimental units (paddocks) in a completely randomized block design with four replicates. Pastures managed with 30-20, 40-15, and 40-20 cm had the highest pre-grazing legume masses (P = 0.0378), but for all GSM, there was a reduction of legume in the forage mass over time (P<0.0001). In Summer 1, legume was observed in the upper strata of the pre-grazing profile for all GMS, but in Summer 2, it was only detected in the 20-25 cm stratum of the 30-20 and 40-20 cm GMS. Pastures managed with 30-20 cm had a high pre-grazing bulk density of total forage, grass, and legume leaf (P<0.05), and a high post-grazing grass leaf mass and bulk density. The highest pre- and post-grazing stem mass and bulk density occurred in pastures with a pre-grazing height of 40 cm (P<0.05). The lower defoliation frequencies (pre-grazing height of 40 cm) had no benefits for the canopy structure. Among the GMS evaluated, a pre-grazing height of 30 cm and a post-grazing height of 20 cm resulted in the most suitable canopy structure for grazing.

ABSTRACT This study evaluated the potential for rearing matrinxã (Brycon amazonicus) with different crude protein (CP) levels and using production performance, water quality, and animal welfare as indicators. To achieve this, 720 juvenile fish (3.65±0.17 g) were distributed in 24 experimental units (200 L). The study, which lasted for 60 days, followed a factorial design (2 × 4) with two production systems: biofloc technology (BFT) and clear water (CW) and four CP levels (24, 30, 36, and 42%) in the diet, with three repetitions for each. We found that the BFT system showed a lower total ammonia level (0.45±0.15 mg/L) compared with CW (1.16±0.50 mg/L). Fish produced in the BFT system exhibited better performance in terms of apparent feed conversion (1.06±0.15), productivity (7.68±2.38 g/m3), and survival (76.95±9.15%). The type of production system affected total leukocytes and neutrophils in the blood. Juvenile matrinxã can be fed a diet containing 30% CP in both production systems. Furthermore, the results demonstrated that bioflocs do not confer a direct benefit to juvenile matrinxã in terms of their feeding; however, the BFT system is a promising alternative for increasing the survival and improving animal welfare during the rearing phase.

ABSTRACT The objective of this study was to evaluate which morphometric variables have the greatest influence on the conformation differences observed in a subpopulation of adult Mangalarga Marchador (MM) horses and to summarize these traits through calculated scores (PCA eigenvectors) to later compare with the scores obtained by these animals during the act of registration. Forty-six morphometric traits were used, which included the 12 mandatory measures of the definitive genealogical registration and two of these new ones: “triangle” and the “Z” of the gait. We used 273 adult MM horses with known genealogy. In addition, their weight and 11 indexes used for functional analysis were calculated. Gait and morphology scores were provided by the Associação Brasileira dos Criadores do Cavalo Mangalarga Marchador (ABCCMM). Initially, the correlations between linear morphometry, angular morphometry, live weight, and functional indexes were analyzed separately. There was a greater proportional reduction of variables among linear measurements (from 32 to 15) than angular traits (from 12 to 7), which did not occur for weight and all the indexes. The low association between PCA scores and the subjective scores for morphology and gait at the registration, coupled with the fact that only six of the 12 mandatory linear measurements were related to the variability of the studied animals, suggests a review of the current registration system to improve sensitivity in the search for phenotypic traits of interest to maintain the current breed standard.

ABSTRACT This study investigates whether pre-pubertal scrotal circumference (SC) and anti-Müllerian hormone (AMH) concentrations indicate sexual precocity in Brahman and Simmental bulls. Fifty-three bulls (Brahman, n = 27; Simmental, n = 26) were used. Scrotal circumference was measured at three periods: pre-puberty (Brahman = 19.99±0.20 months; Simmental = 9.13±0.17 months), puberty (Brahman = 21.42±0.20 months; Simmental = 18.26±0.17 months), and post-puberty (Brahman = 33.34±0.55 months; Simmental = 24.07±0.17 months). A single sample taken at the pre-pubertal period was used for the AMH determination. Two classes were defined based on the frequency distribution of AMH concentrations: low AMH <2.28 ng/mL and high AMH ≥2.28 ng/mL. Scrotal circumference was negatively correlated with the percentage of total defects (r = −0.5957; P = 0.0246) and positively correlated with the percentage of normal sperm (r = 0.595; P = 0.0265). There was a high correlation between SC and assessment periods (pre-puberty, puberty, and sexual maturity) in both breeds (Brahman: r = 0.8776; P = 0.0005; Simmental: r = 0.7483; P = 0.0002). At puberty, SC was higher (P = 0.0002) in animals of the low AMH class (34.78±0.78 cm) than in the high AMH class (32.47±0.42 cm). Males classified as having low AMH concentration had better (P<0.0001) andrological assessments, (vigorous oscillatory movement or vigor: 3.92±0.20; sperm mass movement or turbulence: 2.63±0.19; progressive motility: 77.55±3.80) than those classified as having high AMH concentration (vigor = 3.33±0.19; turbulence = 2.06±0.19; progressive motility = 65.14±3.79). Pre-pubertal AMH concentrations are negatively correlated with SC and are a good predictor of sexual precocity in Brahman and Simmental bulls.

ABSTRACT This study aimed to develop and assess a deterministic mathematical model for predicting the impacts of varying sow replacement rates on the performance of farms producing weaned piglets. Initially, the influence of replacement rate on herd structure was examined using two equations, which accounted for the percentage of sows replaced (55, 45, and 35%), retention rates between parities (13, 9, and 5%), and number of last parities in the herd (6, 7, and 8). The model then estimated sow development throughout the reproductive cycle, starting with an initial weight of 140 kg at first mating and adjusting for weight gains during gestation and losses during lactation, influenced by the varying number of live-born piglets across parities. Energy requirements were calculated using the factorial method, which included maintenance, protein and fat gains, and milk production. The generated data formed various scenarios to derive productive values. These scenarios were analyzed using analysis of variance with the general linear model procedure, treating each scenario as a separate treatment. Early parities (up to P3) contributed 42% in SC-35, 51% in SC-45, and 60% in SC-55. Significant differences were noted in variables such as average parity, birth weight, feed intake during gestation, and average piglet weight gain. The developed model, incorporating replacement gilt modules, gestation, and lactation, can effectively predict herd structure by parity and assess the impact of annual sow replacement rates on the productivity of farms rearing weaned piglets.