Effects of Choline Supplementation in Diets on Juvenile Pacu (Piaractus mesopotamicus): Productive Performance, Proximate Composition and Serum Lipid Level.

INTRODUCTION: Pacu (Piaractus mesopotamicus) is a Brazilian fish species of high commercial value and has emerged as one of the main species with potential for intensive farming. This study aimed to investigate the impact of choline supplementation on productive performance, visceral fat, hepatosomatic indices, proximate composition, serum biochemical profile, and liver coloration in juvenile pacu (Piaractus mesopotamicus). METHOD: The 60-day experiment was conducted in the experimental hatchery of the Study Group of Aquaculture Management - GEMAq of the State University of West Paraná, Brazil. The completely randomized design consisted of five treatments with four replicates each. A total of 200 fish, with an average initial weight and length of 4.25 g and 5.97 cm, were distributed among 20 experimental hapas, resulting in a stocking density of 10 fish per experimental unit. Fish fed a choline-deficient diet exhibited the lowest values for final weight, weight gain, visceral fat, and hepatosomatic index. Conversely, in terms of proximate composition, fish fed choline-deficient diets had the highest moisture content but the lowest crude fat content. Triglyceride levels in juvenile pacu were significantly higher in groups fed diets containing choline (400 to 1200 mg kg-1 ). We also observed significant differences in the cyan color of the liver (P < 0.05). Notably, we observed significant differences in the cyan coloration of the liver (P < 0.05). Other parameters did not exhibit significant changes in response to varying choline levels in the diets. RESULT: Our study demonstrated that choline supplementation in P. mesopotamicus juveniles at an optimal concentration of 400 mg kg-1 significantly impacted growth, metabolism, productive performance, proximate composition, biochemical parameters, and liver color. CONCLUSION: These findings offer crucial guidance for aquaculture professionals, enabling them to enhance growth and health in P. mesopotamicus farming. Further research on choline's influence on lipid metabolism holds potential for more precise dietary recommendations, ultimately improving the efficiency and sustainability of aquaculture practices for this species.

Degradability, in vitro fermentation parameters, and kinetic degradation of diets with increasing levels of forage and chitosan.

Chitosan is the second most important natural biopolymer in the world, extracted from crustaceans, shrimps, and crabs and can modulate rumen fermentation. Our hypothesis is that the addition of chitosan alters the fermentation patterns of different diets for ruminants. This study aimed to evaluate the effects of different levels of chitosan and forage on in vitro dry degradation kinetics and fermentation in a gas production system. The chitosan levels (0, 1625, 3,500, or 7,500 mg/kg of dry matter [DM]) were arranged in a completely randomized block design, and for in vitro ruminal fermentation assay, we used a split splot arrangement. Into the incubator, all chitosan levels were distributed in the four jars, and the forage levels varying on 100, 65, 50, 35, and 20 on DM basis. There was an interaction effect for chitosan and forage levels (P ≤ 0.05) on IVDMD; IVOMD. IVDCP and IVDNDF. Chitosan negatively affected IVDMD in all roughage levels evaluated. The pH and ammonia concentration present effect only for roughage levels and incubation hours. The chitosan did not change (P = 0.3631) the total short-chain fatty acid concentration (overall mean = 21.19 mmol/L) and the C2:C3 ratio (overall mean = 5.85). The IVDCP showed the same decreasing quadratic behavior (P < 0.0001). The increasing chitosan addition increases (P < 0.0001) the gas production and decreases (P < 0.0001) the lag time (parameter C) of diets with greater concentrate participation, characterizing greater efficiency in the degradability of the diet, confirming its potential use in diets for ruminants. Chitosan changes in vitro dry degradation kinetics and fermentation at the minimum dose of 1,722 mg/kg DM for all diets. The roughage level influenced the in vitro nutrients degradability and cumulative gas production.

Importance of naturalized breeds as a base for the formation of exotic sheep (Ovis aries) breeds in tropical altitude regions.

Recent molecular tools and technologies have marked the discovery of the origin and domestication processes of a wide variety of species, using either genomic or mitochondrial molecular markers to provide input for selection programs, as well as the management and conservation of animal breeds. This study aimed to analyze genes of mitochondrial DNA of the following sheep (Ovis aries) breeds: Pantaneira, Bergamácia, Dorper, White Dorper, Ile de France and Hampshire Down, to obtain their population genetic parameters and investigate the origin of these sheep populations reared in the State of Mato Grosso do Sul. The analysis of mitochondrial DNA allowed to infer their phylogenetic relationships and revealed significant differences among them when compared with each other and with sequences obtained from GenBank. Through the formation of haplotypes, it was noted that the Pantaneira breed served as the maternal basis for the formation of the other breeds reared in the region, and it was possible to suggest a European origin for the sheep populations studied.

Economic selection index in small rural dairy farms.

This study aimed to calculate economic values (EVs) and economic selection indices for milk production systems in small rural properties. The traits 305-d milk yield in kg (MY), fat (FP) and protein (PP) percentage, daily fat (FY) and protein (PY) yield, cow live weight in kg (LW), calving interval (CI), and logarithm of daily somatic cell count (SCC) in milk were considered the goals and selection criteria. The production systems were identified from 29 commercial properties based on the inventory of revenues and costs and of zootechnical field data. Later, bioeconomic models were developed to calculate the productive performance, revenues, and costs concerning milk production to estimate EVs, which were calculated as the difference in annual profit with dairy production resulting from a change in one unit of the trait while keeping the others constant and dividing the value by the number of cows. After the EVs were known, ten economic selection indices were estimated for each system so they could be compared by modifying the selection criteria and calculating the relative importance of each selection criteria, the accuracy of the economic selection index, and response expected to the selection in USD, among other parameters. One of the systems detected was called less intensive (LS) and was characterized by having ten cows in lactation that produced 13·5 l/d and consumed 1·8 kg of concentrate/d. The second system detected was called more intensive (IS) and had 22 cows in lactation that produced 17·5 l/d and consumed 3·4 kg of concentrate/d. Monthly profits per cows in lactation of USD 2·60 and USD 68·77 were recorded for LS and IS, respectively. The EVs of the traits MY, FP, and PP were all positive, while for the other traits they were all negative in all situations. The best economic selection indices were those featuring selection criteria MY, LW, and CI, while the trait LW had the greatest importance in both systems. These results indicate that animal frame must be controlled in order to maximize the system's profit.

Genomic selection in dairy cattle simulated populations.

Genomic selection is arguably the most promising tool for improving genetic gain in domestic animals to emerge in the last few decades, but is an expensive process. The aim of this study was to evaluate the economic impact related to the implementation of genomic selection in a simulated dairy cattle population. The software QMSim was used to simulate genomic and phenotypic data. The simulated genome contained 30 chromosomes with 100 cm each, 1666 SNPs markers equally spread and 266 QTLs randomly designated for each chromosome. The numbers of markers and QTLs were designated according to information available from Animal QTL (http://www.animalgenome.org/QTLdb) and Bovine QTL (http://bovineqtl.tamu.edu/). The allelic frequency changes were assigned in a gamma distribution with alpha parameters equal to 0·4. Recurrent mutation rates of 1·0e-4 were assumed to apply to markers and QTLs. A historic population of 1000 individuals was generated and the total number of animals was reduced gradually along 850 generations until we obtained a number of 200 animals in the last generation, characterizing a bottleneck effect. Progenies were created along generations from random mating of the male and female gametes, assuming the same proportion of both genders. Than the population was extended for another 150 generations until we obtained 17 000 animals, with only 320 male individuals in the last generation. After this period a 25 year of selection was simulated taking into account a trait limited by sex with heritability of 0·30 (i.e. milk yield), one progeny/cow/year and variance equal to 1·0. Annually, 320 bulls were mated with 16 000 dams, assuming a replacement rate of 60 and 40% for males and females, respectively. Selection and discard criteria were based in four strategies to obtain the EBVs assuming as breeding objective to maximize milk yield. The progeny replaced the discarded animals creating an overlapping generation structure. The selection strategies were: RS is selection based on random values; PS is selection based on phenotypic values; Blup is selection based on EBVs estimated by BLUP; and GEBV is selection based on genomic estimated breeding values in one step, using high (GBlup) and low (GBlupi) density panels. Results indicated that the genetic evaluation using the aid of genomic information could provide better genetic gain rates in dairy cattle breeding programs as well as reduce the average inbreeding coefficient in the population. The economic viability indicators showed that only Blup and GBlup/GBlupi strategies, the ones that used milk control and genetic evaluation were economic viable, considering a discount rate of 6·32% per year.

Compostagem de resíduo sólido de abatedouro avícola / Composting of solid waste from poultry slaughterhouse

Em virtude da grande demanda por proteína de origem animal, tem-se aumentado a produção de frangos de corte e consequentemente a geração de resíduos provenientes do abate de aves, sendo necessário o desenvolvimento de técnicas que permitam o aproveitamento e reciclagem desses materiais. Objetivou-se com a execução deste trabalho avaliar a eficiência da compostagem no tratamento e reciclagem do resíduo sólido de abatedouro avícola. Utilizou-se resíduo sólido de abatedouro avícola comercial composto por fragmentos de vísceras, tecido muscular, adiposo e ósseo, sangue coagulado e penas e, como fonte de carbono, a casca de arroz. Montou-se uma leira com 1,5m3 de volume inicial, na qual foram monitorados os parâmetros: temperatura, teores de sólidos totais (ST), voláteis (SV), N, P, K, carbono orgânico (C), matéria orgânica compostável (MOC), matéria orgânica resistente à compostagem (MORC), demanda química de oxigênio (DQO), massa e volume enleirados, número mais provável (NMP) de coliformes totais e termotolerantes, bem como suas reduções durante o processo. A temperatura máxima atingida no centro da leira foi de 53,3ºC (média semanal), já as reduções de massa de ST e SV e volume durante o processo de pré-compostagem foram de 36,1; 44,3 e 23,3%, respectivamente, e, durante o processo de compostagem, foram de 21,8; 23,8 e 4,4%. A baixa redução do volume das leiras pode estar associada à alta concentração de MORC (40,1%) que pode ser principalmente relacionada à qualidade da fonte de carbono. O processo promoveu satisfatórias reduções totais de ST, SV e volume, sendo, respectivamente, 50,1; 57,5 e 26,7%. No entanto, foram observadas reduções de 43% na quantidade de nitrogênio presente no composto final. Apesar das reduções de nitrogênio, a compostagem demonstrou ser um método eficiente no tratamento dos resíduos sólidos de abatedouro avícola.

The great demand for animal protein was responsible for the increase on the broilers production and hence, the generation of waste from the poultry slaughter was increased as well, which in turn, propelled the development of techniques that allow the reuse and recycling of these wastes. The objective of this study was to evaluate the efficiency of composting on the treatment and recycling of solid waste from poultry slaughterhouse. The solid waste was from a commercial poultry slaughterhouse and was composed of viscera, muscle, fat, bone, blood and feathers that was mixed with a source of carbon, rice husk. Initially, a windrow with a volume of 1.5m3 was built, and then some parameters were monitored: temperature, total solids (TS), volatile (VS), N, P, K, organic carbon (C), composting organic matter (COC), organic matter resistant to composting (MORC), chemical oxygen demand (COD), mass and volume of the windrow, most probable number (MPN) of total and fecal coliforms, as well as their reductions during the process. The maximum temperature reached in the center of the windrow was 53.3°C (weekly average) since reductions of weight of TS and VS and volume during the pre-composting were 36.1, 44.3 and 23.3%, respectively and during the composting process was 21.8, 23.8 and 4.4%. The low volume reduction can be associated with high concentrations of MORC (40.1%) which can be mainly related to the quality of the carbon source. The process produced satisfactory total reductions of TS, VS and volume that were respectively, 50.1, 57.5 and 26.7%. However reductions were observed in 43% of amount of nitrogen in the final compound. Despite reductions in nitrogen content, composting proved to be an effective method in the treatment of solid waste from poultry slaughterhouse.

Application of microsatellite markers for breeding and genetic conservation of herds of Pantaneiro sheep

Background The aim of the present study was to assess the genetic diversity of Pantaneiro sheep, using microsatellite markers, in order to assist maintenance and management plans, enhance mating systems and reduce the inbreeding rate. A total of 127 animals were genotyped at eight microsatellite loci. They belonged to populations from the Experimental Farm of the Universidade Federal da Grande Dourados (UFGD) (Dourados/MS/Brazil) and Embrapa Pantanal (Corumbá/MS/Brazil). Results The population of Pantaneiro sheep from the UFGD exhibited a high mean number of alleles (11.13) and allelic richness (10.66). The polymorphic information content was highly informative in the locus studied, resulting in a mean value of 0.71. Observed heterozygosity was lower than expected for all molecular markers assessed. The analysis of molecular variance showed a differentiation rate of 5.2% between populations. Conclusions The results of the statistical parameters indicated that populations of Pantaneiro sheep require special attention on herd management, and it's further necessary to implement breeder exchange programs in order to preserve the genetic variability of these populations. Furthermore, the maintenance of those populations in their typical habitats is rather required to allow different responses from the herds to the interactions between genotype and environment.

Association of the leptin gene with carcass characteristics in Nellore cattle.

Advances in DNA technology have created biotechnological tools that can be used in animal selection and new strategies for increasing herd productivity and quality. The objective of the present work was to associate the genotypes of leptin gene exon 2 polymorphisms with productive traits in Nellore cattle. Blood was collected from Nellore males and PCR-RFLP reactions were performed with the restriction enzymes Cla I and Kpn 2I. The gene frequencies resulting from digestion by Cla I were 0.60 and 0.40 for allele A and T, respectively; the genotypic frequencies were AA = 0.20 and AT = 0.80. The gene frequencies from digestion by Kpn 2I were 0.81 for allele C and 0.194 for allele T; the genotypic frequencies were CC = 0.62 and CT = 0.38. The populations in both cases were not in Hardy-Weinberg equilibrium (p > 0.05), and the TT genotype was not found. Significant associations were noted between leptin gene exon 2 polymorphisms and five productive traits in Nellore cattle: carcass fat distribution, the intensity of red muscle coloration, pH, marbling, and post-slaughter fat thickness.

Genetic parameters for milk, fat and protein yields in Murrah buffaloes (Bubalus bubalis Artiodactyla, Bovidae)

The objective of the present study was to estimate genetic parameters for test-day milk, fat and protein yields and 305-day-yields in Murrah buffaloes. 4,757 complete lactations of Murrah buffaloes were analyzed. Co-variance components were estimated by the restricted maximum likelihood method. The models included additive direct genetic and permanent environmental effects as random effects, and the fixed effects of contemporary group, milking number and age of the cow at calving as linear and quadratic covariables. Contemporary groups were defined by herd-year-month of test for test-day yields and by herd-year-season of calving for 305-day yields. The heritability estimates obtained by two-trait analysis ranged from 0.15 to 0.24 for milk, 0.16 to 0.23 for protein and 0.13 to 0.22 for fat, yields. Genetic and phenotypic correlations were all positive. The observed population additive genetic variation indicated that selection might be an effective tool in changing population means in milk, fat and protein yields.