Centro de Ciências Agrárias
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/11727
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Resultados da Pesquisa
Item Feedlot performance of Nellore bulls fed high-concentrate diets containing the association of tannins and saponins with sodium monensin(Brazilian Journal of Animal Science, 2024) Ferracini, Jéssica Geralda; Lelis, Ana Laura Januário; Polli, Daniel; Gasparim, Mariana Bassanezi; Feba, Luanda Torquato; Prado, Ivanor Nunes; Millen, Danilo DominguesThe objective of this study was to evaluate the performance of Nellore bulls finished in the feedlot and fed high-energy diets containing sodium monensin associated or not with tannins and saponins. Ninety-six Nellore bulls were used with an average initial body weight of 350.6±17.9 kg. The bulls were weight-blocked and randomly allocated to 12 pens, which were considered the experimental units. The treatments were assigned to the pens according to the blocks, as follows: sodium monensin (25 ppm; SM) and sodium monensin (25 ppm) plus tannins (350 ppm) and saponins (3.92 ppm, SM+TS). The bulls received an adaptation diet for the first 19 days, a growing diet from day 20 to day 59, and a finishing diet from day 60 to 98 of the experimental period. The animals were slaughtered after 98 days of study. The addition of tannins and saponins to the diets of feedlot Nellore cattle did not change the dry matter intake, hot carcass weight, and dressing percentage; however, it increased body weight by 2.0% and average daily gain by 5.4% and improved feed conversion by 4.3%. The addition of tannins and saponins to high-concentrate diets containing sodium monensin improves the productive performance of Nellore cattle finished in a feedlot for 98 days.Item Genetic polymorphisms in SIRT5 gene and their association with carcass traits in Congjiang Xiang pigs(Brazilian Journal of Animal Science, 2024) Zhang, Xiong; Wang, Jing; Zhao, Chunping; Zhang, JingThis study was conducted to investigate the polymorphism of the silence information regulator 5 (SIRT5) gene in 103 Congjiang Xiang pigs from Southwest China. We searched for SNP (single nucleotide polymorphism) loci of SIRT5 gene through sequence alignment and PCR. We obtained nine SNP loci: g.14135 A>C (intron 6), g.14247 C>A (intron 6), g.14305 C>T (exon 7), g.14335 C>T (exon 7), g.16603 T>C (intron 7), g.16613 T>C (intron 7), g.16800 G>A (intron 7), g.16812 C>G (intron 7), and g.16916 A>G (exon 8). Further analysis of SNP genotypes associated with the carcass traits of skin thickness, backfat thickness, and eye muscle area was carried out in pigs. We found that the genotypes g.14305 C>T (CC) and g.16812 C>G (CG) had certain advantages for improving the carcass traits of Congjiang Xiang pigs. The haplotype combination of the SIRT5 gene that improved skin thickness was H2H3:CCGGCTCA. These results may provide empirical support for molecular-based breeding of carcass traits in Congjiang Xiang pigs.Item Beta-lactam antimicrobials activity and the diversity of blaZ gene in Staphylococcus aureus isolates from bovine mastitis in the northwest of Portugal(Brazilian Journal of Animal Science, 2024) Hnini, Rachid; Silva, Eliane; Pinho, Luís; Najimi, Mohamed; Thompson, GertrudeThis study aimed to assess the antimicrobial susceptibility of 52 Staphylococcus aureus (S. aureus) bovine mastitis isolates obtained from 37 dairy herds from the northwest of Portugal against antibiotics belonging to the β-lactam family, evaluate the detection of blaZ and mecA resistance genes, and study the diversity of positive isolates. The antimicrobial susceptibility tests were performed by the disk diffusion method. The detection of blaZ and mecA genes was performed using specific polymerase chain reaction (PCR) and the diversity of blaZ was evaluated by phylogenetic analysis. The antimicrobial susceptibility test showed a prevalence of phenotypic resistance by S. aureus of 52.0% against penicillin and ampicillin, 34.6% against oxacillin, 17.3% against amoxicillin plus clavulanic acid, and 21.1% against cefazolin. A prevalence of phenotypic intermediate resistance of 5.7% against penicillin, 9.6% against amoxicillin plus clavulanic acid, and 1.9% against ampicillin and cefazolin, respectively, was demonstrated. A 100.0% phenotypic susceptibility was found against piperacillin. Of the 52 S. aureus isolates, 35 (67.3%) were PCR positive for blaZ gene, and isolate 25 was positive for mecA gene. The phylogenetic analysis of partial blaZ gene S. aureus isolates consensus sequences were placed in two different clades, clade A (cluster A, A.1) and B (cluster B), all closely related to animal and/or human S. aureus strains. Isolate 2 appeared in the phylogenetic tree as the most divergent. This study indicates that blaZ resistance gene plays a role in β-lactam resistance in the tested bovine mastitis S. aureus isolates within dairy herds in the northwest of Portugal, especially in case of penicillin and ampicillin antibiotics that have shown a high phenotypic prevalence. Indeed, the proportion of bovine mastitis isolates with phenotypic resistance did not agree with the proportion of those identified for blaZ, as isolates with 100.0% of phenotypic susceptibility for all tested antibiotics also harbored blaZ. BlaZ phylogenetic analysis from S. aureus isolates showed diversity inside or between different herds in the northwest of Portugal. Piperacillin, as a suggestion, could be tested for S. aureus bovine mastitis treatment in the future to evaluate this new possibility of therapy.Item Identification of parameters that affect the conception rate of precocious Nelore heifers before the start of the breeding season(Brazilian Journal of Animal Science, 2024) Silva, Geancarlos Carraro da; Silveira, Marcos Vargas da; Silva, Aldair Félix da; Gheller, Janaina Menegazzo; Silva, Wilian Aparecido Leite da; Fernandes, Henrique Jorge; Costa-e-Silva, Eliane Vianna da; Melo-Sterza, Fabiana de AndradeThe objective of this study was to identify parameters, before the start of the breeding season, that affect the conception rate of precocious Nelore heifers through ultrasonographic ovarian evaluation and evaluation of weight and body condition score (BCS). A total of 407 heifers aged 404±69 days (≈14 months old), weighing 267.1±31.2 kg, and with mean BCS of 3.1±0.5, were used. Heifers were subjected to hormone treatment to induce cyclicity and, 30 days later, to a fixed-time artificial insemination (FTAI) program with three managements. Morphometric measurements of ovaries and ovarian structures were performed by transrectal ultrasonographic evaluation, as well as weighing and evaluation of BCS on D −30 and D0. Conception rate was evaluated 30 days after FTAI. The conception rate of heifers did not vary according to ovary diameter, weight, BCS, and age at first calving. However, heifers with the presence of follicle with a diameter > 6 mm at D −30 and D0 had a higher conception rate at the first FTAI. The presence of a dominant follicle greater than 6 mm at D −30 is an efficient complementary criterion to identify 14-month-old Nelore heifers with greater ability to conceive at the first FTAI before the breeding season. Antral follicle count performed on D −30 is not a good tool to predict fertility at the first FTAI, and the weight may not be a limiter to select heifers under good nutritional and health management.Item Effects of Acacia mearnsii De Wild. extract and monensin on intake, digestibility, and ruminal variables of lambs(Brazilian Journal of Animal Science, 2024) Ribeiro, Simone da Silva; Vedovatto, Marcelo; Palmer, Elizabeth Anne; Franco, Gumercindo LorianoThis study evaluated the effects of tannin extract of Acacia mearnsii De Wild. or monensin on intake, digestibility, nitrogen balance, and ruminal variables of lambs. Five rumen cannulated lambs (40.3 ± 2.8 kg) were used in a 5 × 5 Latin square design, with periods of 21 days each. The treatments were: control, without additive; Tan-0.60, Tan-1.20, and Tan-1.80 for the doses of 0.60, 1.20, and 1.80 g kg−1 body weight (BW) of tannin extract, respectively; and ionophore (monensin) at 0.75 mg kg−1 of BW. Tannins reduced the digestibility of dry matter (DM) and the greatest effects were observed for Tan-1.80. Tannins also increased or tended to increase the fecal excretion of DM, and the greatest effects were observed for Tan-1.20 and Tan-1.80. Tannins increased the fecal excretion of N, decreased the amount of N in urine, but did not affect N retained. Furthermore, tannins reduced the concentration of valerate and the acetate:propionate ratio and increased propionate without affecting the amount of total volatile fatty acids, and the greatest effects were observed for Tan-1.80. The use of ionophore only increased the elimination of N in the urine. Thus, monensin does not affect nitrogen retention, and tannin impairs digestibility, but increases propionate production.Item Performance and bone health of broilers reared under artificial lighting and supplemented with different levels of vitamin D3(Brazilian Journal of Animal Science, 2024) Lopes, Tainá Silva Brandão; Vasconcelos, Mariana Diniz Costa; Costa, Bruno Teixeira Antunes; Sousa, Lorena Salim; Bertassoli, Bruno Machado; Ocarino, Natália de Melo; Serakides, Rogéria; Lara, Leonardo José Camargos; Araújo, Itallo Conrado SousaThis study aimed to investigate the effects of different levels of vitamin D3 in broiler diets on performance and bone health. A total of 360 one-day old male Cobb500® broiler chicks were subjected to five treatments of different levels of vitamin D3 in diets during two rearing phases: 0 IU/kg in both phases; 625 IU/kg in starter and 500 IU/kg in grower phase (25% of commercial inclusion); 1,250 IU/kg in starter and 1,000 IU/kg in grower phase (50% of commercial inclusion); 1,875 IU/kg in starter and 1,500 IU/kg in grower phase (75% of commercial inclusion); and 2,500 IU/kg in starter and 2,000 IU/kg in grower phase (100% of commercial inclusion). The traits studied weekly were feed intake, body weight, feed conversion, and viability. At 21 and 35 days of age, tibiae and femurs were removed, dissected, and evaluated for dry matter (DM), ash (%MM), calcium (%Ca), phosphorus (%P) and breaking strength. At 35 days of age, the bones were subjected to histopathological analysis for macroand microscopic morphological evaluation. Data were subjected to regression analysis, using α = 0.05. The variables of percentage %MM, %Ca, %P, and breaking strength experienced a positive linear effect up to the supplementation levels of approximately 25% of inclusion. The histopathological analysis found that the group that received the diet with 100% inclusion of vitamin D3 presented lesions compatible with osteopetrosis and tibial dyschondroplasia. The observed results showed that for isonutritive diets, reduced levels of vitamin D3 guaranteed performance during the evaluated period while the use of 100% of vitamin D3 , as commonly used, can cause bone diseases and harm the welfare of broilers.Item Evaluation of the effects of an emulsifier and two lipid sources on growth performance and intestinal morphology of broiler chickens(Brazilian Journal of Animal Science, 2024) Oliveira, Marcus Vinícius Garcia de; Silva, Júlia Marixara Sousa da; Batista, João Marcos Monteiro; Café, Marcos Barcellos; Mello, Heloisa Helena de Carvalho; Oliveira, Helder Freitas de; Pires, Marília Ferreira; Leandro, Nadja Susana Mogyca; Jacob, David VanniThis study aimed to evaluate the effect of including an emulsifier (soybean lecithin) and two lipid sources (soybean oil and chicken fat) on the performance and intestinal morphology of broiler chickens. A total of 576 one-day-old Cobb® 500 male chicks were housed in a completely randomized design, with treatments divided in a 2 × 2 factorial arrangement (with and without emulsifier and two lipid sources - soybean oil or chicken fat), totaling four treatments with eight replications and 18 chicks per plot. The experimental diets were formulated to be isoenergetic and isoproteic. The use of chicken fat improved the live weight at the starter rearing stage. However, the use of the emulsifier improved the live weight at the grower and finisher phases. No interaction effect was observed between treatments for performance. The intestinal morphology showed an increase in duodenal villus height with the use of chicken fat and emulsifier. The ileum had an increase in villus height in chickens fed the diet with soybean oil and emulsifier. Supplementation of the emulsifier resulted in positive results in the live weight of chickens at 35 and 42 days of age, in addition to increasing the villus height in the small intestine.Item Prebiotic composed of yeast (Saccharomyces cerevisiae) cell wall improves performance in broiler diets(Brazilian Journal of Animal Science, 2024) Fornazier, Roberto; Ribeiro Junior, Valdir; Albino, Luiz Fernando Teixeira; Tavernari, Fernando de Castro; Feddern, Vivian; Silva, Diego Ladeira da; Serafini, Suélen; Petrolli, Tiago Goulart; Paiano, Diovani; Calderano, Arele Arlindo; Boiago, Marcel Manente; Rostagno, Horacio SantiagoThis research aimed to evaluate the influence of a commercial prebiotic in different concentrations upon several parameters. To carry out the experiment, 640 male one-day-old broiler chicks were distributed in four treatments (0, 0.5, 1.0, and 1.5 kg/ton of yeast cell wall) with eight replicates of 20 birds per experimental unit, in randomized blocks. Prebiotic effects were assessed on performance, carcass yield and prime cuts, in addition to the litter quality (its content of nitrogen and phosphorus). There were significant improvements for weight gain and feed conversion ratio in experimental growth periods. However, prebiotic level at 1.0 kg/ton is enough to provide improvement in performance and similar yield parameters than the control group. Also, 1.5 kg/ton prebiotic inclusion in the diet promotes environmental benefits by reducing the phosphorus amount in the litter by 51%. Above 1.0 kg/ton prebiotic addition in broiler diets can be safely recommended, because it promotes both performance and environmental benefits.Item Genetic parameters, prediction of selection gains and genetic diversity in Andropogon lateralis Nees ecotypes(Brazilian Journal of Animal Science, 2024) Silveira, Diógenes Cecchin; Sampaio, Rodrigo; Valentini, Arthur; Santos, Weliton Menezes dos; Longhi, Júlia; Nauderer, Carla; Machado, Juliana Medianeira; Mills, Annamaria; Simioni, Carine; Brunes, André Pich; Weiler, Roberto Luis; Dall’Agnol, MiguelThe objective of this study was to estimate the genetic parameters and predict selection of genetic gains and genetic diversity of 12 Andropogon lateralis ecotypes collected in the State of Rio Grande do Sul, Brazil. To estimate genetic parameters and predict selection gains, the REML/BLUP technique was applied. Genetic diversity among the ecotypes was evaluated by two clustering methods (optimization and hierarchical) and principal component (PC) analysis, the latter method also used to discard variables. The genetic parameters studied showed high potential for selection of important agronomic forage traits for livestock production. Results showed that the 12 A. lateralis Nees ecotypes exhibited high genetic variability for the studied forage characters and indicated parental prosperity for crosses within the genetic breeding program. Principal component analysis showed that number of total vegetative tillers, leaf:stem ratio, number of reproductive tillers, and leaf dry matter yield accounted for 80.6% of the observed variation in PC1. These variables are important characteristics for quantifying the dry matter production and nutritional value of forage plants, and they can help to discriminate amongst ecotypes. Ecotypes sourced from the Pelotas, Piratini, Passo Fundo, Bagé, and Montenegro regions showed superior forage production when evaluated by the BLUP methodology. Therefore, this group was identified as the most suitable for selection and crossing purposes. Tocher’s cluster analysis grouped the ecotypes into five divergent groups. Principal component and UPGMA hierarchical methods were also efficient at separating the ecotypes.Item Genetic structure and diversity of Santa Inês sheep flocks in Central Northern Brazil(Brazilian Journal of Animal Science, 2024) Deus, Alzira Regina Silva de; Silva, Geice Ribeiro da; Sena, Luciano Silva; Britto, Fábio Barros; Rocha, Artur Oliveira; Carvalho, Débora Araújo de; Sousa, Fabiana Cristina Belchior de; Santos, Natanael Pereira da Silva; Sarmento, José Lindenberg RochaThe objective of this study was to assess the genetic structure and diversity of six Santa Inês sheep flocks from the Central-Northern Brazil. A panel of 20 highly polymorphic and informative microsatellite loci was selected and amplified. The following parameters were obtained: overall mean of number of alleles = 15.4; expected heterozygosity (He) = 0.89; polymorphism information content (PIC) = 0.88; discriminatory capacity = 0.95; combined probability of identity = 1.50 × 10−34; and probability of exclusion = 1.00. The flocks with the lowest and the highest degrees of genetic variability were Farm 6 (He = 0.70, PIC = 0.653, and allelic richness [Ar] = 3.76) and Farm 1 (He = 0.89, PIC = 0.882, and Ar = 4.39), respectively. Indications of genetic bottleneck were observed in all flocks, as well as moderate genetic differentiation, with FST = 0.053, RST = 0.096, and Dest = 0.169. The migration rate in all flocks was high, with a trend towards Farm 1. This finding was not in agreement with the substructure found with the Bayesian admixture analysis and corroborated the array obtained with the principal component analysis and the clustering analysis. The results revealed moderate structuring and high genetic diversity in the flocks. However, management strategies should be reviewed, as evidence of bottleneck and genetic erosion was observed.