Resumo em Inglês:

ABSTRACT This study aimed to analyze the effect of grasslands, meadows, and pastures on the efficiency of dairy farming and cattle farming in Türkiye and European Union countries. The primary data for this study included information on the production of raw milk and cattle meat, nitrogen content in treated manure, dairy cow populations, livestock standard units (LSUs), and the extent of grasslands, meadows, and pastures in both European Union countries and Türkiye. In the study, two distinct models were developed: one to assess dairy farming efficiency and the other to evaluate cattle farming efficiency. Dairy farming refers specifically to the production system that focuses on milk production from dairy cows. In contrast, cattle farming is a broader term that encompasses both dairy cattle and beef cattle. Data envelopment analysis was used to calculate the efficiency scores. The difference between dairy farming and cattle farming efficiency values was tested using the Mann-Whitney U test, and the results indicated a statistically significant difference in total efficiency (z = −2.462, P = 0.014) and technical efficiency (z = −3.416, P = 0.001) values. The significant difference in total efficiency values suggests that cattle farming is more efficient than dairy farming. Regarding grasslands, meadows, and pastures, countries with below-average grassland areas showed higher total efficiency values for cattle farming. Additionally, in countries where meadow and pasture areas are below average, total efficiency values for both dairy farming and cattle farming were higher. These findings suggest that the higher efficiency values observed in countries with below-average meadow and pasture areas may be explained by the structural characteristics of their production systems. In the absence of abundant natural forage resources, farmers are likely to adopt more intensive and resource-efficient management strategies, which enhance both total and scale efficiency. In other words, the scarcity of grassland acts as a driving force toward optimizing input utilization, resulting in improved efficiency outcomes in both dairy and overall cattle farming.

Resumo em Inglês:

ABSTRACT The objective of this study was to perform a financial analysis of a dairy farm located in the southern region of Rio Grande do Sul, comprising 500 hectares and a herd of 380 lactating Holstein cows, with an average daily milk production of 12,000 liters, during the year 2022. Based on the collected data, the total revenue (TR), fixed and variable costs and expenses were analyzed monthly and for the entire period. Additionally, operating profit (OP), contribution margin (CM), percentage contribution margin (CM%), break-even point (BEP), and break-even point output (BEP output) were calculated. A vertical analysis was conducted to determine the cost share in producing one liter of milk. The average revenue, costs and expenses, and gross profit per liter of milk were US$ 0.47 (R$ 2.41), US$ 0.40 (R$ 2.05), and US$ 0.07 (R$ 0.36), respectively. The CM and CM% were equal to US$ 815,036.08 and 39.84%, respectively. The BEP was equal to US$ 1,248,297.34, and the BEP output was 2,660,396.5 liters of milk. The most significant production costs were related to feed, accounting for 63.12% of the total cost. Labor and machinery maintenance ranked the second and third largest cost components, representing 10.01% and 9.10%, respectively. Except for the month of March, revenues exceeded costs and expenses throughout the year 2022 on the studied farm. The financial analysis of the property supports the adoption of strategies aimed at increasing profitability.

Resumo em Inglês:

ABSTRACT This study quantified production risks and economic feasibility in tropical pasture-based beef systems by integrating a rule-based Minimum Module (MM) framework with Monte Carlo simulation (@Risk 8.0) in Excel 365 using a Microsoft Visual Basic 6.0 algorithm. Twelve scenarios combining low (0.5 animal unit [AU] ha⁻1), medium (1.0 AU ha⁻1), and high (1.5 AU ha⁻1) stocking rates across 2017–2020 were each run with 10,000 stochastic iterations to identify the smallest viable herd size and pasture area that ensured non-negative net present value (NPV ≥ 0). Intensification increased per-hectare productivity from 3.3 to 9.8 arrobas ha⁻1 yr⁻1 (P<0.001) and reduced minimum grazing area by 53–63 percent (P<0.001). Risk profiles remained favorable, with negative gross margin in only 0.25% of iterations and negative total profit in 15.55% of iterations. Fixed-cost share declined from approximately 74% in low-intensity to approximately 48% in high-intensity systems (P<0.05). Strong co-movement among overhead inputs (ρ>0.90) and among variable-cost inputs (ρ>0.80), and a land-for-feed trade-off (ρ ≈ –0.35) were quantified. The MM tool delivers transparent “what-if” scenario testing for herd and land planning without complex optimization, enabling data-driven feed-price hedging and stocking-rate adjustments.

Resumo em Inglês:

ABSTRACT The study aimed to assess the effects of pre-exposure to lavender aromatherapy on horse behavior in stalls and during therapy sessions at the Equine Therapy Center of Cavalo Crioulo/IFRS. Eight therapy horses underwent three control (water diffusion) followed by three aromatherapy trials (water + five drops of diffused lavender essential oil for 30 min) in the stalls. Each trial was on a separate day/week over six consecutive weeks. Total time spent (min) and frequency of behavior in the stalls (head in the window, standing by the diffuser, head down, agitated) and then during the 20-minute therapy sessions (balk, bite, lean on the embarkation, quit session, head-butts) were determined. Perception of treatment-blind handlers who prepared and guided the horses during the therapy sessions was assessed with a closed survey after they ceased. Compared with control trials, diffused lavender aromatherapy resulted in horses spending more time with their heads down (21.2±1.3 vs. 26.9±1.4 min, P = 0.004), lower proportion of agitated behavior (12.5% vs. 87.5%, P<0.0001) and fewer visits to the stall’s window (29.2% vs. 65.2%, P = 0.003). The duration of head-butting was half post lavender exposure (0.14 vs. 0.06±0.01 min, P<0.05) and frequency of this behavior and biting the handlers during the sessions were approximately 2.5 times lower post-aromatherapy (P<0.05). According to most handlers (77%), horses were calmer than usual post-aromatherapy with no impediment to horse performance. Horses subjected to lavender essential oil diffused for 30 min before therapy sessions were calmer and easier to handle, suggesting that aromatherapy is a relevant and practical approach to improve horse welfare within animal-assisted therapy settings.

Resumo em Inglês:

ABSTRACT To conduct an optimal breeding and selection program, it is necessary to understand the genetic underpinnings of the desired traits. Early growth is an indicator of future success in the production and reproduction of buffaloes. This study aimed to estimate the (co)variance components for growth traits of Anatolian buffalo calves in Yozgat by employing six animal models with the different combinations of additive genetic, maternal genetic, maternal permanent effects, and covariance between offspring and dam. Birth weight (BW), six-month weight (SMW), twelve-month weight (TMW), and average daily gain (ADG) were analyzed with the data collected from 2726 Anatolian buffalo calves born between 2016 and 2023. Estimation of variance components and genetic parameters for growth traits of Anatolian buffaloes was performed with WOMBAT software. For each trait, Akaike’s information criterion was used to detect the most appropriate model. The results showed that the best-fitted models explaining the variation in weights at birth (BW), six (SMW), and twelve (TMW) months of age and average daily gain (ADG) were models 3, 4, 1, and 1, respectively. Direct heritabilities for BW, SMW, TMW, and ADG were estimated in the range of 0.04±0.09-0.14±0.06, 0.23±0.09-0.49±0.15, 0.36±0.18-0.68±0.31, and 0.41±0.19-0.86±0.33, respectively. Maternal heritabilities for same traits were ranged between 0.02±0.09-0.04±0.03, 0.02±0.09-0.36±0.15, 0.05±0.14-0.22±0.24, and 0.00±0.15-0.20±0.25, respectively. This study unveiled genetic variability for growth traits in Anatolian buffaloes, suggesting that focusing selection efforts on these traits holds considerable promise for enhancing overall performance.

Resumo em Inglês:

ABSTRACT Tilapia is one of the most cultivated species in Mexico and an important fishery resource in the Aguamilpa Reservoir, contributing to the local food supply and economy. However, little is known about its genetic diversity and population structure in this reservoir. This study analyzed the genetic diversity of tilapia from the Aguamilpa Reservoir using SSR markers. According to morphological criteria, three species of the genus Oreochromis were identified, and 85 alleles were detected at five loci. The observed levels of heterozygosity and polymorphic information content (PIC) indicated high genetic variability, with 78% of the samples showing values greater than 0.5, which indicates substantial genetic variability. The fixation index (Fst = 0.028) and AMOVA showed low genetic differentiation among populations. Principal coordinates analysis (PCoA) and a dendrogram evidenced overlap among individuals, indicating the absence of a defined population structure and random exchange of alleles among populations. These results suggest that the reservoir's tilapia populations function as a single, homogeneous genetic unit, providing valuable information for the sustainable management and conservation of this fishery resource.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the effects of two different dry matter contents at ensiling on the chemical composition, fermentation products, microbial profile, and aerobic stability (AS) of wilted ryegrass (Lolium multiflorum L.) silages, with or without microbial inoculants. The ryegrass was wilted in the field until it reached 32 or 45% DM. In addition to DM contents, the effect of adding or not adding microbial inoculants to the forage was evaluated, resulting in the following treatments: Control - no additive (C); commercial inoculant - Magniva Platinum 2 (INO); and commercial inoculant plus enzymes - Magniva Platinum 3 (INO+E). The silos were stored for 62 days. In the 32% DM treatment, the inoculated silages showed higher DM content and lower pH than the control, indicating a more favorable fermentation profile. Silages at 32% DM exhibited lower pH (3.97), higher levels of lactic, acetic, and propionic acids, and a greater population of LAB. The lower DM treatments also showed reduced DM and gas losses, absence of effluent, and lower DM losses during aerobic exposure. The inoculants increased lactic acid production and decreased propionic and butyric acid concentrations. At 32% DM, INO and INO+E inoculants significantly improved in vitro estimates of DM, OM, and NDF digestibility. Yeast and mold counts were low (<10-4), with no colony development at the lowest dilution tested. Total DM (8.6 g kg−1 DM), gas (8.1 g kg−1 DM), and effluent losses (0.51 kg/ton wet basis) were minimal across all treatments. At 32% DM, silages treated with INO presented negative values for gas and DM losses. AS was high for all silages (353 and 328 h for treatments 32 and 45% DM, respectively), with greater stability observed in 32% DM treatments. The inoculants enhanced AS in 45% DM silages and reduced DM losses over 20 days of aerobic exposure. The 32% DM harvest led to better quality silages. Microbial inoculants were effective in improving fermentation and preservation of ryegrass silages by reducing fermentative losses at 32% DM and enhancing aerobic stability at 45% DM.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the effects of calcium oxide (CaO) and a mixture of corn heavy steep water and sugarcane molasses (HM) on the fermentation, aerobic stability, and ruminal disappearance of corn husk silage. Three doses of CaO (0, 20, and 40 g/kg of fresh matter (FM)) and three doses of HM (0, 100, and 200 g/kg of FM) were arranged factorially and applied to rehydrated corn husk (500 g/kg moisture) in a completely randomized design, with four replicates per treatment. Treated corn husk was placed in nylon-polyethylene bags (33 cm × 45 cm, 160 μm thick), vacuum sealed, and stored for 66 d. Significant HM × CaO interaction (P<0.05) were observed for chemical composition, including crude protein (CP) and ash-free neutral detergent fiber (aNDFom), as well as for key fermentative parameters, notably lactic, acetic, and n-butyric acids. CaO increased silage pH, with the highest dose exceeding pH 7 after 66 d of storage, indicating a high buffering capacity. Aerobic spore-forming bacteria and lactic acid bacteria (LAB) counts increased with HM and CaO, respectively, while molds decreased with CaO. Clostridia counts tended to increase with CaO, and n-butyric acid increased with both additives, suggesting reduced hygienic quality of the silage. Dry matter (DM) loss was reduced, and aerobic stability was extended by CaO, indicating inhibition of microbial metabolism. However, HM alone increased aerobic spoilage. Both additives enhanced ruminal DM disappearance, while CaO slightly improved in situ disappearance of aNDFom. Corn husk ensiled without additives already exhibited considerable ruminal DM and aNDFom disappearance, as well as good preservation. In conclusion, corn husk (500 g/kg moisture) may be ensiled without additives or, if convenient, added with up to 100 g/kg of HM.

Resumo em Inglês:

ABSTRACT The objective of this study was to investigate the influence of nitrogen (N) input via fertilizer or through the inclusion of an N-fixing legume mixed with grass on canopy structural characteristics, forage production, and stocking rate in grazing systems. Three pastures type (PT), with Marandu palisadegrass (U. brizantha), were assessed: i) monoculture without N fertilizer application (Unfertilized); ii) monoculture fertilized with 150 kg N ha⁻1 year⁻1 (N-fertilized); iii) and mixed pasture with forage peanut (A. pintoi), without N fertilizer (Mixed). The treatments were managed under mob stocking with variable stocking rate. The canopy height target was between 25 and 30 cm (pre-grazing), and 15 cm (post-grazing). Beef cow-calf pairs were used (529 ± 49 kg cows and 80 ± 29 kg calves) for grazing. The pre-grazing total herbage mass was not influence for the PTs (P = 0.111), which averaged 7,234 kg ha⁻1. The greatest and lowest pre-grazing herbage mass were recorded for the N-fertilized and Unfertilized. The N-fertilized and Mixed had the greatest post-grazing herbage mass (P = 0.012). The legume proportion in the Mixed was on average 30.5%. The N-fertilized and Mixed showed the greatest herbage accumulation rate. The lowest herbage accumulation rate was recorded in the Unfertilized. Stocking rate was reduced by 35.7 and 78.5% in the Mixed and Unfertilized, respectively, compared with the N-fertilized pasture, with the Unfertilized averaging 0.9 AU ha⁻1. Overall, N-input is crucial for maintaining and supporting adequate carrying capacity in pasture ecosystems. Thus, forage peanut legume provides a way to add N with lower economic and environmental costs.

Resumo em Inglês:

ABSTRACT The objective was to evaluate the structural traits and forage accumulation of elephant grass genotypes under two stubble heights. The experiment was conducted in a factorial scheme, with five genotypes (P 2022 S1, 1810, 2111, 2035 and BRS Kurumi) and two stubble heights (25 and 45 cm), in a randomized block design, with three replications, considering the rainy and dry periods. Forage accumulation of the rainy period was higher for genotype 2111 (P<0.05) compared to P 2022 S1 and BRS Kurumi. The 1810 and 2035 genotypes showed forage accumulation similar to 2111. In the dry period, forage accumulation values were approximately 35% of those observed in the rainy period, with the BRS Kurumi and P 2022 S1 genotypes presenting lower values (P<0.05) compared to the others. The stubble height of 25 cm resulted in lower canopies (82 cm) than that at 45 cm (96 cm). The genotypes P 2022 S1 and 2111 had a higher percentage of leaves and a lower percentage of stem at the stubble height of 45 cm. The genotypes 2111 and 1810 were superior to BRS Kurumi for the percentage of leaf blade and stem at the defoliation height of 45 cm. In the dry season, the genotype 2111 showed the highest leaf-stem ratio. The genotypes 1810, 2111, 2035 and BRS Kurumi showed the highest leaf and lowest stem percentage. The defoliation height of 45 cm resulted in higher forage density. The genotypes 2035, 2111 and 1810 stood out for the high forage accumulation and leaf percentage at both stubble heights during the rainy season. Management with a defoliation height of 45 cm increases the leaf blade percentage and the leaf-stem ratio and reduces the proportion of stem in the forage harvested above the residue.

Resumo em Inglês:

ABSTRACT Three experiments were carried out to evaluate the effects of the following commercial inoculants: Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and L. buchneri (LP+LB) at 2.5 × 105 CFU g−1; as well as L. rhamnosus, L. buchneri, and L. diolivorans (LB+LD) at 2.5 × 105 CFU g−1; and the same inoculants at double dosage (2LB+2LD) at 5.0 × 105 CFU g−1. In Exp. 1, corn silage was uninoculated and inoculated with LP+LB and LB+LD and stored in 5-L jars for 15, 30, 45, and 90 d. In Exp. 2, reconstituted corn grain and, in Exp. 3, whole-ear corn silage (snaplage) were uninoculated and inoculated with LP+LB, LB+LD, and 2LB+2LD and stored for 60 d. The fermentation products, microbial counts, and aerobic stability (AS) were assessed. In Exp. 1, the LP+LB inoculant reduced (P = 0.03) the pH at 30 d. The LP+LB inoculant resulted in a higher (P<0.001) LAB count at 90 d. The lactic acid (LA) concentration was higher at 45 and 90 d (P<0.001). The LB+LD inoculant resulted in higher acetic acid (AA) and propionic acid (PA) content at 45 and 90 d (P<0.001). Inoculation reduced (P = 0.02) losses. In Exp. 2, LA was higher (P = 0.001) in silages inoculated with LP+LB and LB+LD than in the other treatments. Higher (P<0.001) AA and PA were observed with the 2LB+2LD inoculant compared with the other silages. In Exp. 3, lower pH (P = 0.001) and higher LA (P = 0.001) were observed with the LP+LB inoculant than in the other treatments. Inoculation with 2LB+2LD resulted in higher (P<0.001) AA and PA than the other treatments. In corn silage, inoculation with LB+LD enhanced fermentation from day 45, promoting higher acetic and propionic acid concentrations and greater AS. The AS of rehydrated corn grain and snaplage was improved by LB+LD, but only when the double dose was applied.

Resumo em Inglês:

ABSTRACT Five bagger configurations were evaluated for their effects on physical characteristics, fermentation, and starch degradability in corn (Exp. 1) and sorghum (Exp. 2) grain silages. Both experiments were conducted using five treatments, involving baggers with different nominal power ratings (60, 75, and 90 hp; designated as M-60, M-75, and M-90). The treatments consisted of the following configurations: M-60 equipped with a standard roll; M-75 and M-90 equipped with intermediate and coarse rolls for corn; and fine and intermediate rolls for sorghum. Three bags were produced for each treatment, for a total of 15 silos (experimental units) per experiment. Treatments were considered fixed effects, whereas bags nested within treatments were considered random effects. Means were compared using Tukey’s test at 5%. The degree of grinding of corn and sorghum grains, as well as its effects on silage fermentation and starch degradability was assessed. No differences were observed in fermentation and microbial counts. In Exp. 1 (corn), M-60 + standard roll exhibited greater degradability (72.6%; P = 0.02). In corn, coarse rolls (M-75 and M-90) increased particle retention on 4.75 mm sieves and reduced particle retention on 1.70 and 1.18 mm sieves, resulting in an increase in geometric mean diameter (GMD; P = 0.01). In Exp. 2 (sorghum), intermediate rolls increased the proportion of larger particles, the GMD (P = 0.003), and the number of whole grain kernels, especially with M-90 (P = 0.015). Overall, for ensiling corn in silo bags, the M-60 + standard roll and the M-75 and M-90 + intermediate rolls are suggested, as these combinations enhance grain disruption and starch degradability. For sorghum, using fine rolls on the M-75 and M-90 baggers is recommended to improve grain fragmentation.

Resumo em Inglês:

ABSTRACT Freezing is one of the fundamental preservation techniques for increasing the shelf-life of meat. However, the quality of frozen meat is highly dependent on the thawing process. Thus, the current study sought to investigate the effects of freeze-thawing processing on protein degradation, lipid oxidation, microbiological spoilage, and qualitative parameters of two types of beef muscles: Longissimus lumborum and Semitendinosus. Beef muscles were collected from ten steer carcasses of at approximately 15 months of age with a mean body weight of 440 ± 50 kg, at 24 h post-mortem at a commercial slaughterhouse. The muscles were divided into two groups randomly: chilled or frozen-thawed. The freezing and thawing processes resulted in significantly higher degrees of protein and lipid oxidation in meat, resulting in reduced pH, moisture retention ability, and color stability. During the freeze-thawing process, there was a higher desmin degradation but no change in troponin T degradation. Frozen-thawed meat samples exhibited significantly increased growth of total aerobic count, Pseudomonas spp., Enterobacteriaceae, and coliform counts than those from chilled samples. Due to freezing-thawing, Longissimus lumborum muscle was more color-stable and had greater water holding capacity than Semitendinosus muscle (P≤0.05). The data indicate that freeze-thawing consistently caused protein degradation, fat oxidation, color deterioration, and reduced water holding capacity in both beef muscle types. Therefore, to avert quality deterioration during frozen storage, it is imperative to consider the characteristics of each beef muscle.

Resumo em Inglês:

ABSTRACT Laying hens’ gut health and microbiota are directly linked to their productivity, egg quality, and overall welfare. This study evaluated the impact of different fiber sources on the performance Dekalb laying hens (63 to 71 weeks of age) and egg quality at 67 and 71 weeks. At the end of the trial (71 weeks), organ development was assessed, and the cecal microbiota was characterized using 16S rRNA sequencing. Birds were divided into four groups: a diet with elephant grass (Pennisetum purpureum Schum), a diet with commercial insoluble fiber, a control diet without added fiber, and a diet with soybean hulls, with five replicates of 26 hens each. Fiber inclusion did not affect egg production, egg mass, feed conversion per dozen or per egg box, or eggshell quality (P>0.05). However, hens fed elephant grass had higher final body weight (P≤0.05), while soybean hulls improved feed conversion, reduced costs, and increased egg weight in the first evaluation (67 weeks; P≤0.05). Additionally, diets with soybean hulls led to a higher yolk percentage but a lower albumen percentage (P≤0.05). Beta diversity analysis revealed greater bacterial diversity in hens fed elephant grass compared with those in the control and soybean hull groups (P≤0.05). Soybean hulls increased the abundance of the Selenomonadaceae family, while elephant grass favored the genera Bacteroides, Megamonas, and the species Faecalibacterium prausnitzii. These findings indicate that elephant grass, soybean hulls, and commercial insoluble fiber are viable alternatives in layer hen diets to improve microbial diversity and gut health in poultry, with soybean hulls standing out as a cost-effective option for maintaining performance and egg quality.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the effect of functional amino acid and mineral supplementation on growth performance, carcass characteristics, meat quality, and fatty acid profile of finishing pigs. One hundred and twenty castrated male pigs with an initial weight of 59.7 ± 2.7 kg were used, distributed into four dietary treatments: control; amino acids, control + 0.5% Arg and 0.5% Leu; minerals, control + 0.1% Cr and 0.05% MgO, and amino acids + minerals. From 127 to 159 days of age, pigs fed the amino acid diet had greater average daily gain (ADG; P = 0.015), while those fed the amino acid + mineral diet showed improved feed conversion ratio (FCR; P<0.001) compared with the control diet. Across the entire experimental period (98 to 159 days), amino acid supplementation increased ADG (P = 0.043), whereas amino acid and amino acid + mineral diets improved FCR (P = 0.029). However, pigs fed the amino acid + mineral diet had lower ADG compared with pigs fed the amino acid diet. Carcass traits were largely unaffected, but pigs fed the amino acid + mineral diet had reduced backfat thickness (P = 0.015). Meat quality was influenced by amino acid supplementation, with reduced thawing loss (P = 0.001) and total water loss (P = 0.041). Regarding the fatty acid profile, amino acid and mineral diets increased oleic acid concentrations (P = 0.021), and mineral supplementation increased monounsaturated fatty acids (MUFA; P = 0.047). In summary, amino acid supplementation improved growth performance, water-holding capacity, and oleic acid concentration, whereas mineral supplementation increased the concentration of oleic acid and MUFA. The combination of amino acids and minerals improved FCR and reduced backfat thickness, but this was accompanied by lower ADG, indicating a lack of consistent synergistic benefits.

Resumo em Inglês:

ABSTRACT This study used a systematic review and meta-analysis to evaluate a model for estimating the available phosphorus (aP) requirements of broilers. Databases (PubMed, Scopus, and Web of Science) were searched using the PICo methodology, including 90 studies from 1997–2023. The variables analyzed included performance (average daily gain (ADG) and feed efficiency (FE)) and bone traits (tibia P, ash, and shear force), expressed relative to the highest response in each study. The aP levels were compared to the Brazilian Tables for Poultry and Swine (BT), which were considered 100% aligned with the BT recommendations. Nonlinear regressions assessed the responses by phase (starter, grower, and finisher). In the starter phase, aP intake to maximize ADG and FE was 99% of the BT recommendations, with similar results for FE during the grower phase (99%), indicating slight overestimation. However, the ADG requirements in the grower and finisher phases were underestimated (102% of BT recommendations). The FE in the finisher phase matched BT recommendations (100%). Bone traits required a slightly higher aP intake (>100%) across all phases. The BT model reliably estimates aP needs, but may require additional supplementation to optimize bone mineralization.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the effects of lysine (Lys) restriction on compensatory growth, body composition, and nitrogen balance of growing-finishing pigs before and after immunocastration. Sixty-four entire male pigs (39.2 ± 6.8 kg) were randomly assigned one of four treatments: Control diet (CON; no restriction) or diets with restriction of Lys level in 14 (Lys-14), 28 (Lys-28) and 42% (Lys-42) of estimated Lys requirements for entire growing pigs (Lys restriction phase, from 0 to 28 d). From 29 to 64 d, all animals received the same diet, formulated to meet the nutritional requirements of entire males (repletion phase 1). Repletion phase 2 (from 65 to 86 d) began immediately after the administration of the second dose of immunocastration. The CON diet and common diets fed from 29 to 64 d and 65 to 86 d were formulated to meet or exceed nutrient requirements. Growth performance and body composition variables reduced linearly (P≤0.05) as dietary Lys restriction increased, except for the final body lipid which tended to reduce linearly (P<0.10). In the repletion phase 1, no difference was observed for average daily feed intake (ADFI), ADG and G:F (ADG/ADFI) among pigs previously fed CON and Lys-restricted diets regardless of the restriction degree (P>0.05). Final body weight (BW) and final body protein were similar between the groups of pigs previously fed CON or Lys-14 diets (P>0.05). At the end of the repletion phase 2, pigs previously fed CON diet had similar final body protein than pigs previously fed Lys-14 or Lys-28 diets. Regarding the highest Lys restriction evaluated (Lys-42), a total catch-up was evidenced only for the final body weight.

Resumo em Inglês:

ABSTRACT The objective of this study was to evaluate the inclusion of high-protein dried distillers’ grains (HP-DDG) in broilers’ diets. A total of 1,200 one-day-old male chicks were weighed and distributed among six treatments, with ten replicates of 20 birds each. The experimental period was divided into three phases: starter (1–21 days), grower (21–33 days), and finisher (33–43 days). The treatments consisted of six dietary levels of HP-DDG in the starter, grower, and finisher phases as follows: T1: 0%; T2: 3, 5, and 7%; T3: 5, 7, and 9%; T4: 7, 9, and 11%; T5: 9, 11, and 13%; and T6: 11, 13, and 15%. Body weight (BW), BW gain (BWG), feed intake (FI), and feed conversion ratio (FCR) were measured at 21, 33, and 43 days of age. In addition, carcass and cut yields were assessed at 43 days. Data were submitted to ANOVA and analyzed using Dunnett’s test (α = 0.05). In the starter phase, birds fed diets with 11% had lower BW (P = 0.032) and BWG (P = 0.029) than the control group. Overall performance from 1 to 33 days and from 1 to 43 days of age was not affected by HP-DDG levels (P>0.05). Carcass and cut yields at 43 days were not affected by HP-DDG (P>0.05). In conclusion, the gradual inclusion of HP-DDG in broiler diets up to 15% does not impair overall performance or carcass yield. However, inclusion levels should not exceed 9% during the starter phase to avoid initial growth loss.

Resumo em Inglês:

ABSTRACT The effects of dietary supplementation with enzymatic complexes and plant extracts on weaned piglets were evaluated. Sixty piglets (28 days old) were assigned to six treatments: Control diet (CD); CD with 125 g/ton of Yucca schidigera extract (CDY); CD with 200 g/ton of enzymatic complex (CDE); CD with 400 g/ton of multi-enzymatic complex with emulsifier (CDME); CDE + 125 g/ton YSE (CDE+Y1) and CDE + 250 g/ton YSE (CDE+Y2). Piglets on the CDE+Y1 diet had better feed conversion ratio (P<0.05). CDE, CDME and CDE+Y1 improved digestibility of dry matter, organic matter, fiber, energy and phosphorus, reducing phosphorus excretion (P<0.05). CDME improved jejunum morphology, increasing villus height, mucosal thickness and absorptive area (P<0.05), while CDE+Y2 reduced goblet cells (P<0.05). YSE increased serum GGT levels; phosphorus levels were lower with CDE+Y2 and AST was reduced in the CD group (P<0.05). Exogenous enzymes combined with plant extracts lowered TNF-α mRNA expression and increased nutrient transporter expression (SGLT-1, NaPi-IIb, PEPT-1) (P<0.05). Overall, enzymatic additives, with or without plant extracts, improved feed efficiency, nutrient digestibility and intestinal health. However, further research is needed to elucidate the effects of the interaction between enzyme complexes and plant extracts.

Resumo em Inglês:

ABSTRACT This study evaluated the effects of supplementing drinking water with an acidifier blend on growth performance, serum biochemical profile, and gastrointestinal microbial counts of broilers. A mixture containing phosphoric, citric, and tartaric acids was supplied at 0, 60, or 150 mL/1000 L of drinking water during specific production phases. A total of 320 Cobb male broilers were allocated in a completely randomized design with eight replicates of 12 birds each. The acidifier progressively reduced drinking water pH values (5.54, 3.17, and 2.72, respectively). No effects (P>0.05) were observed on final body weight, feed intake, or feed conversion ratio. A quadratic trend (P = 0.087) was observed for total mesophilic bacterial counts in the crop, with the lowest point estimated at 103.87 mL/1000 L, whereas jejunal bacterial counts were not affected. Quadratic responses (P<0.01) were also observed for serum total protein, globulin, cholesterol, and uric acid concentrations, while albumin was not influenced (P>0.05). Supplementation of drinking water with a blend of citric, tartaric, and phosphoric acids at 150 mL/1000 L was safe, did not impair broiler performance, and maintained serum biochemical values within normal ranges. Quadratic responses among the evaluated concentrations (0, 60, and 150 mL/1000 L) suggest a potential inclusion range between 85 and 157 mL/1000 L associated with favorable outcomes. These findings indicate that the evaluated acid blend may contribute to gut health and represents a promising alternative to antibiotic growth promoters.

Resumo em Inglês:

ABSTRACT The study was carried out with the objective of investigating the enrichment of weaned piglet diets with selenium proteinate (SeP) and sodium selenite (SeS) at two inclusion levels. A total of 40 piglets, averaging 6.60 ± 1.06 kg, were assigned to five dietary treatments: a control diet, and diets supplemented with selenium proteinate (0.15 or 0.30 mg/kg) or sodium selenite (0.15 or 0.30 mg/kg). The SeP-0.30 diet reduced average daily feed intake (ADFI) (P<0.05) in both periods and average daily gain (ADG) (P = 0.017) in the second period. Diets with selenium proteinate improved the digestibility of dry matter (DM; P = 0.024) and organic matter (OM; P = 0.024). All selenium-enriched diets increased selenium retention (P<0.05). The addition of 0.30 mg/kg of selenium reduced villus height (VH) (P = 0.001), villus width (VW) (P = 0.001), crypt depth (CD) (P<0.0001), and mitotic rate (P = 0.031). Sodium selenite reduced apoptosis in the jejunal epithelium (P = 0.020) and increased hepatic selenoprotein P (SePP) expression (P = 0.038). High concentrations of sodium selenite elevated hepatic selenoproteins, serum creatinine (CRC), and Immunoglobulin A (IgA) concentrations. Supplementation with sodium selenite should not exceed 0.30 mg/kg, whereas selenium proteinate is recommended at up to 0.15 mg/kg. Increasing selenium, particularly as proteinate, yields positive results, but levels above 0.30 mg/kg may be detrimental.

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ABSTRACT The aim of the study was to evaluate the inclusion of carotenoids in the diet of layers on the production performance, quality and oxidative stability of eggs during storage. A total of 240 Dekalb White laying hens, 76 weeks of age, were used. The hens were allocated in completely randomized design with eight diets (control diet (CD); astaxanthin (AXT), 10 mg kg⁻1; lutein (LUT), 10 mg kg⁻1; lycopene (LYC), 10 mg kg⁻1; AXT + LUT, 10 mg kg⁻1 each; AXT + LYC, 10 mg kg⁻1 each; LUT + LYC, 10 mg kg⁻1 each; and AXT + LUT + LYC, 10 mg kg⁻1 each), five replicates, and six birds per experimental unit. Egg quality and oxidative stability were evaluated using a randomized 8 × 3 factorial design (diets × storage period: fresh, 15, and 30 days) with repeated measures. Eggs were stored either at room temperature (RT, 25 °C) or under refrigeration (RF, 8 °C) for the evaluation of egg quality and lipid stability. Dietary supplementation with astaxanthin (AXT; 10 mg kg⁻1), lutein (LUT; 10 mg kg⁻1), and lycopene (LYC; 10 mg kg⁻1), either individually or in combination, did not affect the zootechnical performance or overall egg quality of laying hens. However, AXT supplementation improves the oxidative stability of eggs compared with LYC, suggesting a greater protective effect against oxidative deterioration. Combined supplementation with AXT + LUT, AXT + LYC, and LUT + LYC enhances yolk pigmentation, whereas the simultaneous inclusion of all three carotenoids reduces pigmentation intensity. Regardless of dietary treatment, egg storage for up to 30 days at room temperature (25 °C) or under refrigeration (8 °C) negatively affects the internal quality of eggs.

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ABSTRACT This study evaluated the effects of xylanase combined with increasing amylase levels in broiler diets containing protease and phytase on performance, intestinal histomorphology, cecal short-chain fatty acid profile, serum interleukin (IL) levels, and economic viability over a 28-d period. A completely randomized experimental design was adopted in a 2 × 3 + 1 factorial arrangement (100 or 200 U kg−1 amylase × 0, 1,000 and 2,000 U kg−1 xylanase + positive control (PC), without enzymes), with seven replicates of 20 birds. Diets with amylase and xylanase also included 2,500 U kg−1 protease, whereas all diets had 500 U kg−1 phytase. Enzyme matrix values accounted for 100 kcal of metabolizable energy and 6% of crude protein and digestible amino acids. At 14 d, broilers receiving xylanase levels presented better feed conversion ratio (FCR) compared with those fed diets without xylanase (P = 0.014). However, regardless of the enzyme supplementation level, FCR was worse compared with PC (P = 0.0001). Diets containing 100 U kg−1 amylase resulted in better histopathology scores (I See Inside®). No difference (P>0.05) was observed between PC and enzyme-supplemented groups for intestinal morphometric parameters, concentrations of acetic, butyric and isovaleric acids, or serum levels of IL-6, IL-10 and IL-16 at 28 d. Feed cost/t of broilers fed 100 U kg−1 of amylase or 1,000 U kg−1 of xylanase was 3.15% and 3.24% lower, respectively, than PC. Although the inclusion of amylase and xylanase in reduced-energy and protein diets containing protease and phytase did not improve the broiler performance and did not match the PC group, it maintained gut health and immunological parameters. The use of 100 U kg−1 of amylase and 1,000 U kg−1 of xylanase enabled an average 3.25% reduction in production cost.

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ABSTRACT This study aimed to evaluate the potential of using images taken with a smartphone or scanner as alternatives to conventional spectrophotometry for phosphorus (P) analysis of feedstuff. Twenty-four samples of feed ingredients and commercial concentrates were evaluated. After acid digestion and dilution, the solutions were analyzed using the P-molybdate colorimetric reaction. Standards ranged from 0 to 1.4 mg L−1 at intervals of 0.2 mg L−1 of P in the reading solution. Standards and reading solutions were analyzed in ELISA microplates. The absorbance values of each cuvette were obtained using a spectrophotometer, and smartphone and scanner images were obtained sequentially. The images were segmented, and a circle was sampled in each cuvette to obtain the mean values of the red, green, and blue (RGB) channels. The P concentration was determined using linear regression of absorbance or the mean values obtained in the RGB channels as a function of P concentration. The repeatability (REP), limits of detection (LOD), and limits of quantification (LOQ) were calculated. Except for the scanner’s blue channel (P<0.10), image-based colorimetric methods provided similar P concentrations similar to those obtained by spectrophotometry (P>0.10). Using absorbance, the REP, LOD, and LOQ were 0.96%, 0.013, and 0.039 mg L−1, respectively. The best-performing image-based predictors were red and green channels of the smartphone, with REP, LOD, and LOQ values of 1.80%, 0.050, 0.150 mg L−1 and 2.11%, 0.074 and 0.223 mg L−1, respectively. The smartphone red channel spectrophotometric absorbance provided equivalent P concentrations at a 99% confidence interval. Smartphone images performed better than scanner images. The use of the mean red channel from smartphone images proved promising for determining P concentration in feeds.

Resumo em Inglês:

ABSTRACT The use of digital technologies and wearable sensors has advanced in precision livestock farming. However, there is still no clear definition of the most suitable models for the use of sensors in grazing animals, especially under tropical systems. Thus, we aimed to compare the performance of six predictive models for grazing cattle behavior and to evaluate different testing strategies. The study was conducted in a pasture area, using nine Tabapuã heifers monitored by triaxial accelerometers attached to the nape, with data recorded every second. Ninety-six 12-h visual observations were performed and combined with sensor data to generate two datasets: grazing vs non-grazing (GNG) and grazing, ruminating, and idling (GRI). The models tested were generalized linear model (GLM), random forest (RF), k-nearest neighbors (KNN), gradient boosting (GB), light gradient boosting (LGB), and artificial neural network (ANN), with hyperparameter optimization performed via Bayesian search. Seven testing strategies were applied, including random holdout (RHO), leave-animal-out (LAO), leave-height-out (LHO), with four different sward heights, and an external test, obtained in a previous study. All models, except GLM, showed good performance (~80% accuracy for GNG); however, the inclusion of three classes reduced the average accuracy by 6.4%. LGB and KNN were the most computationally efficient models, in terms of data process time, while ANN was the most demanding. Testing strategies that reduced data dependence (LAO and LHO) decreased accuracy, highlighting the importance of real-world scenarios for the development of robust commercial applications. It is recommended to balance accuracy and computational cost, prioritizing LGB, GB, or KNN for practical applications. Moreover, testing strategies under different farm conditions or using external datasets should be performed.

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ABSTRACT Rooster fertility has a considerable impact on reproductive efficiency in broiler breeder management, with semen quality being an important factor in fertilization success. This study evaluated the effects of age and body weight on semen quality measures in Ross 308 broiler breeder males. Twenty-four roosters were allocated into two age groups (25-29 weeks and 30-39 weeks) and three body weight categories (underweight: 3.0-3.5 kg; normal: 4.0-4.5 kg; overweight: 5.0-5.5 kg). The volume, concentration, motility, and viability of sperm samples were evaluated. Sperm motility was affected by age and body weight. Older roosters showed higher motility (69.33%) than younger ones (41.26%). Roosters with normal body weight had better sperm motility (84.0%) than roosters that were underweight (44.17%) or overweight (46.33%). Semen volume increased with age only in overweight roosters, whereas other parameters were not significantly affected. These findings underline need to maintain an optimal body weight to optimize fertility, while also acknowledging the beneficial effects of advancing age on sperm motility. Age-specific weight management strategies may improve reproductive performance in broiler breeder males.

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ABSTRACT The objective of this study was to investigate the potential carryover effect of narasin (NAR) supplementation during the backgrounding phase on subsequent feedlot performance and gastrointestinal morphometrics of finishing Nellore bulls. Ninety-six bulls were used in a 2 × 2 factorial design, evaluating conditional NAR supplementation on the backgrounding phase (control [CON] or NAR) and finishing supplementation (sodium monensin [MON] or NAR), resulting in four treatments as follows: 1) CON+MON, 2) CON+NAR, 3) NAR+MON, and 4) NAR+NAR. During the backgrounding phase, NAR-fed cattle showed reduced dry matter intake (DMI) expressed in kilograms and as a percentage (P≤0.03), however, it did not significantly affect final body weight (BW), average daily gain (ADG), or feed efficiency compared with the CON-fed cattle (P≥0.14). In the finishing phase, neither backgrounding nor finishing supplementation, nor their interaction, had significant effects on BW, ADG, DMI, feed efficiency, hot carcass weight, dressing percentage, or gastrointestinal morphometrics (P≥0.11). Relative to CON+NAR and NAR+MON, cattle fed NAR+NAR showed reduced fluctuation in DMI throughout the entire experiment (%; P≤0.02); however, fluctuations, even above 10% in some treatments, did not lead to reduced ADG or increased rumenitis incidence. We conclude that dietary supplementation with NAR did not enhance performance or gastrointestinal development in Nellore cattle during backgrounding or finishing, nor was a carryover effect observed between phases. Although NAR-fed cattle in the finishing phase performed similarly to those receiving monensin, the absence of a negative control limits interpretation, warranting further research on its role in stabilizing dry matter intake.

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ABSTRACT The objective of this study was to assess the effect of corn silage particle size on feeding behavior, blood parameters, fecal characteristics, and growth performance of beef heifers. Corn silage was harvested at 37.9 ± 1.6% dry matter (DM) using a self-propelled harvester containing shredding rolls and set to either a 13-mm theoretical length of cut (TLC), designated as conventional particle size (CPS), or a 24-mm TLC, designated as long particle size (LPS). Ninety-six Nellore heifers (initial shrunk body weight = 248 ± 36 kg) were randomly assigned to one of two treatments [3 heifers per pen; 16 pens (replicates) per treatment]. Treatments consisted of a finishing diet containing either CPS or LPS. Heifers were fed for 101 days, with the first 15 days serving as the adaptation period. Feeding behavior was evaluated on days 47 and 69, fecal samples were collected on days 58 and 78, and ultrasound backfat thickness, ribeye area, and blood samples were assessed on the day of slaughter. Statistical analysis was performed using the MIXED procedure in SAS (α = 0.05). No differences were observed in initial body weight, final body weight, ADG, hot carcass yield, carcass traits, or feed efficiency (P≥0.05). However, the DM intake of heifers fed LPS (7.98 kg/d) was higher than that of heifers fed CPS (7.55 kg/d) (P = 0.031). Although treatments did not significantly affect ingestive behavior (P≥0.05), heifers receiving the LPS diet exhibited a 15% increase in NDF intake (P = 0.006). Fecal pH tended (P = 0.052) to be 1.3% higher in LPS-fed heifers. Overall, an increase in corn silage particle size led to higher intake without compromising feed efficiency. Nevertheless, the treatments had no significant effect on chewing activity or the performance of finishing beef heifers.

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ABSTRACT Vitamin A is listed in the fat-soluble vitamins group, whose absorption, transport, and storage are similar to the lipids. However, the vitamin A functions go beyond those reported in the ocular cells’ metabolism being also described in reproductive functions, growth, and specific tissue maintenance through gene regulation. In ruminants, vitamin A supplementation can be done in different ways. Orally with carotenoids which β-carotene is the main representative, and intramuscularly by injectable applications of synthetic vitamin A. In cows, it is common to perform oral supplementation with β-carotene in the middle and/or final third of gestation to increase plasma retinol concentrations, benefiting the fetus, colostrum synthesis, and reproductive indices. In newborn calves, vitamin A administrated intramuscularly might favor cell differentiation for lipogenesis increase in muscle tissue indicating a higher intramuscular fat degree and resulting in a future improvement in meat quality. Thus, this review aimed to address the vitamin A supplementation dynamic on the effect on gestational/maternal and neonatal metabolism in beef cattle.

Resumo em Inglês:

ABSTRACT This study aimed to evaluate the effects of incorporating the Angus breed into a rotational crossbreeding system involving the Charolais and Nellore breeds. The experiment included 67 calves born in 2021, which were allocated to four treatments according to their genetic composition: calves with Charolais predominance (PCH), Nellore predominance (PNE), and F1 Angus-cross calves with Charolais (AACH) or Nellore (AANE) maternal predominance. Calves were monitored from birth to seven months of age, and dams were evaluated from calving to weaning. Differences in birth weight were observed among the treatments (P<0.05), with mean weights of 35.8, 38.0, 31.7, and 33.2 kg for PCH, PNE, AACH, and AANE, respectively. Post-weaning average daily gain also differed among treatments (P<0.05), with higher gains for AACH (0.716 kg/day) and AANE (0.655 kg/day) compared to PCH (0.518 kg/day) and PNE (0.474 kg/day). No significant differences were found in milk yield among treatments (P>0.05), with a mean daily production of 5.60 L and a total production of 432 L. Mating rotationally crossbred (Charolais × Nellore) cows with Angus bulls improved calf performance, particularly after weaning, due to increased individual heterozygosity. Additionally, the reduced birth weight of these calves may decrease the risk of dystocia without impairing growth. This strategy appears to be effective for enhancing productivity in cow-calf systems.

Resumo em Inglês:

ABSTRACT The study evaluates the impact of feeding the same amount of corn grain at different times on animal production, carcass characteristics, and meat quality. At weaning, 60 steers (176 kg) were divided into six groups assigned to one of two dietary treatments (n = 3). In dietary treatment one (DT1), steers grazed an endophyte-free tall fescue pasture to 330 kg of LW and then (Phase-3) were fed a corn grain-based diet for 90 d before slaughter. In dietary treatment two (DT2), steers were fed a cracked corn grain-based diet for 90 d after weaning (Phase-1) and then grazed until slaughter, being supplemented with cracked corn grain in Phase-3. To reach the same total amount of grain intake in both treatments, in Phase-3, DT2 was supplemented with the amount of grain being fed to DT1 minus DT2 average grain intake in Phase-1. The average daily gain in DT1 was lower in Phase-1 than in DT2, but greater in Phase-2 and Phase-3. Final live weight, hot carcass weight, ribeye area and subcutaneous fat thickness were greater (P<0.50) in DT1 than in DT2, but marbling score and intramuscular fat content did not differ (P>0.100). Meat from DT1 had greater L*, a*, and b* values than DT2 (P<0.05), but the subcutaneous fat had a lower b*-value (P<0.001). The longissimus dorsi muscle shear-force did not differ (P = 0.255), and minor differences were observed in meat fatty acid composition. The n-6:n-3 ratio and C18:1 trans-10/trans-11 proportion were greater (P<0.050), and the C20:5 proportion was lower (P = 0.002) in DT1 than in DT2. Thus, the corn grain feeding strategy during the fattening period did not affect meat marbling score or intramuscular fat content, shear force, or fatty acid profile, but did affect meat color as well as subcutaneous fat thickness and color.