7 research outputs found
Meat quality of lambs fed different saltbush hay (Atriplex nummularia) levels
Climate changes have increased soil and water salinity, compromising animal produc- tion especially in dry areas where scientists have become more interested in halophyte plants, like saltbush. The effects of saltbush hay levels (30, 40, 50 and 60%) were evaluated based on physical-chemical, nutritional and sensory parameters of Santa Ine^s lamb meat. Thirty-two 8-month-old castrated Santa Ine^s lambs, with initial weights of 22±1.97 kg were used; they were slaughtered after 60 days in the feedlot. The pH, colour, moisture, protein and cholesterol contents did not differ among treatments. Panelists observed a greater inten- sity of lamb smell and flavour (P=0.0035) in the meat of animals that received more con- centrate in the diet. An increase in the inclu- sion of saltbush increased ash percentage (P=0.0232), total saturated (P=0.0035) and polyunsaturated (P=0.0287) fatty acids and reduced the lipids (P=0.0055) and the n-6:n-3 ratio (P=0.0058) of the meat. Therefore, salt- bush hay can be used as a feeding resource in regions with problems of water and soil salini- ty because it does not impair the physical- chemical, nutritional and sensory quality of sheep meat
Study On The Introgression Of Beef Breeds In Canchim Cattle Using Single Nucleotide Polymorphism Markers
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The aim of this study was to evaluate the level of introgression of breeds in the Canchim (CA: 62.5% Charolais-37.5% Zebu) and MA genetic group (MA: 65.6% Charolais-34.4% Zebu) cattle using genomic information on Charolais (CH), Nelore (NE), and Indubrasil (IB) breeds. The number of animals used was 395 (CA and MA), 763 (NE), 338 (CH), and 37 (IB). The Bovine 50SNP BeadChip from Illumina panel was used to estimate the levels of introgression of breeds considering the Maximum likelihood, Bayesian, and Single Regression method. After genotype quality control, 32,308 SNPs were considered in the analysis. Furthermore, three thresholds to prune out SNPs in linkage disequilibrium higher than 0.10, 0.05, and 0.01 were considered, resulting in 15,286, 7,652, and 1,582 SNPs, respectively. For k = 2, the proportion of taurine and indicine varied from the expected proportion based on pedigree for all methods studied. For k = 3, the Regression method was able to differentiate the animals in three main clusters assigned to each purebred breed, showing more reasonable according to its biological viewpoint. Analyzing the data considering k = 2 seems to be more appropriate for Canchim-MA animals due to its biological interpretation. The usage of 32,308 SNPs in the analyses resulted in similar findings between the estimated and expected breed proportions. Using the Regression approach, a contribution of Indubrasil was observed in Canchim-MA when k = 3 was considered. Genetic parameter estimation could account for this breed composition information as a source of variation in order to improve the accuracy of genetic models. Our findings may help assemble appropriate reference populations for genomic prediction for Canchim-MA in order to improve prediction accuracy. Using the information on the level of introgression in each individual could also be useful in breeding or crossing design to improve individual heterosis in crossbred cattle. © 2017 Buzanskas et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.12202663/09-0, CAPES, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior449564/2014-2, CNPq, Conselho Nacional de Desenvolvimento Científico e TecnológicoCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Análise genética de características reprodutivas na raça brahman
Aiming to establish selection criteria for the
Brahman cattle in Brazil, the objective of this paper
was to estimate genetic and environmental
parameters for birth weight (BW), gestation length
(GL) and scrotal circumference at 365 (SC365),
455 (SC455) and 550 (SC 550) days of age, and
relative efficiency of indirect versus direct selection
for these traits. Data were obtained from 15 851
animals belonging to 16 herds in six states, enrolled
in a genetic breeding program. (Co)variance and
heritability coefficients and genetic and environ-
mental correlations between traits were estimated
by restricted maximum likelihood (REML) under a
multi trait animal model. The model included as fixed
effects the contemporary group and the age of
cow at calving as a covariate (linear and quadratic),
and as random the direct genetic, the permanent
environmental and residual effects. For BW and
GL it was also considered the maternal genetic
effect as random. Estimates of direct heritabilities
were 0.36, 0.29, 0.55, 0.43 and 0.40 for BW, GL,
SC365, SC455 and SC550, respectively. Genetic
correlations between BW and GL, GL and SC365,
GL and SC455, GL and SC550, SC365 and SC455,
SC365 and SC550 and SC455 and SC550, were
respectively 0.06, 0.13, 0.20, 0.13, 0.96, 0.98 and
0.99. The heritabilities estimates for all traits
indicated these show enough additive genetic
variability to respond favorably to selection. For
sexual precocity, the best option would be SC365,
due to the high value of heritability and to indirect
selection at this age being more efficient than
direct selection for PE455.Para fins de estabelecer critérios de seleção
para a raça Brahman, no Brasil, este estudo
objetivou estimar parâmetros genéticos e ambien-
tal para peso ao nascer (PN), período de gestação
(PG) e perímetro escrotal aos 365 (PE365), 455
(PE455) e 550 (PE550) dias de idade e eficiências
relativas de seleção indireta versus a direta para
essas características. Os dados referem-se a
15 851 animais de 16 rebanhos de seis estados,
participantes de um programa de melhoramento
genético. Componentes de (co)variância e coefi-
cientes de herdabilidade e de correlações
genéticas e ambientais entre características foram
estimados pelo método da máxima verossimilhança
restrita, sob modelo animal multi-característica.
No modelo, foram incluídos como efeitos fixos,
grupo de contemporâneos e idade da vaca ao
parto como covariável (efeitos linear e quadrático)
e, como efeitos aleatórios, genético aditivo direto,
ambiente permanente da vaca e resíduo. Para PN
e PG considerou-se ainda o efeito aleatório genético
materno. As herdabilidades estimadas para PN,
PG, PE365, PE455 e PE550 foram, respectivamen-
te, 0,36; 0,29; 0,55; 0,43 e 0,40. As correlações
genéticas entre PN e PG, PG e PE365, PG e PE455,
PG e PE550, PE365 e PE455, PE365 e PE550 e
PE455 e PE550 foram, respectivamente, 0,06;
0,13; 0,20; 0,13; 0,96; 0,98 e 0,99. Todas as
características apresentaram variabilidade
genética aditiva suficiente para responder
favoravelmente à seleção. No que tange a
precocidade sexual, a melhor opção seria PE365,
devido à alta herdabilidade estimada, além de que
a seleção indireta a esta idade seria mais eficiente
que a direta para PE455