ABSTRACT
ABSTRACT The birth of fraternal twins is a characteristic frequently observed in callitrichids. Cytogenetic studies have demonstrated hematopoietic chimerism in marmosets with the occurrence of two cell lines 2n=46,XX/46,XY in females and males co-twins, without phenotypic changes. Amplification by PCR have also been used to verify the presence of the SRY gene in female chimaeras. Our aim was to verify the occurrence of chimerism in Callithrix sp. individuals considered as hybrids according to their intermediate phenotypes between C. jacchus and C. penicillata. Blood samples from 37 Callithrix sp. individuals were collected. Hematopoietic chimerism 2n=46,XX/46,XY was detected by cytogenetic analysis in five individuals, three males and two females. A fragment of approximately 200bp of the SRY gene was amplified in seven females with normal external genitalia. The percentage of 32% of chimeric individuals detected in the present study is similar to that observed for pure specimens of Callithrix. These data suggests that hybridization probably does not interfere with the occurrence of twin gestation, nor of chimerism. Although cytogenetics is the main tool to identify the two cell lineages present in cases of chimerism, the amplification of the SRY gene by PCR has proved to be more efficient to identify the Y chromosome in cases of chimeric female marmoset.
Subject(s)
Animals , Male , Female , Callithrix/genetics , Chimerism , Polymerase Chain Reaction , Cytogenetics , Genes, sry , Karyotype , Litter Size/geneticsABSTRACT
Profitability of sheep production depends on the reproductive response of ewes and growth of their lambs, which can be improved through the ram genotype. The aim of this study was to evaluate the reproductive response of Blackbelly (Bb), Pelibuey (Pb), Katahdin (Kat) and Dorper (Dor) ewes crossed with Damara (Dam) and Dor rams and the growth of their offspring. To measure percentage of single and multiple lambings (MLP), 234 Bb, Pb, Kat and Dor ewes were used. To measure lamb growth, the offspring of 86 Bb x Pb (BbPb) ewes and 73 Kat x Dor (KatDOR) ewes were used. Four Dor x BbPb, six Dam x BbPb and six Dam x KatDor lambs were slaughtered for carcass assessment. MLP was analyzed with the CATMOD procedure considering the factors age and breed. Lamb growth data were analyzed with the MIXED procedure, and those of carcass characteristics with the GLM procedure of SAS, using weight at slaughter as covariable. MLP was higher (P0.05) by effect of ram breed. It is concluded that Bb ewes are more prolific than Dor ewes; male lambs of Dam rams had post-weaning growth response and carcass yield similar to those of Dor rams, although the female lambs of Dor rams were heavier than those of Dam rams.
Rentabilidade da produção de ovinos depende da resposta reprodutiva de ovelhas e do crescimento de seus cordeiros, o que pode ser melhorado por meio do genótipo masculino. O objetivo deste estudo foi avaliar o desempenho reprodutivo de ovinos Blackbelly (Bb), Pelibuey (Pb), Katadin (Kat) e Dorper (Dor) e o crescimento de cordeiros com carneiros Damara (Dam) e Dor. Para medir a porcentagem de partos simples e múltiplas (MLP), foram utilizados 234 ovelhas Bb, PB, Kat e Dor. Para medir o crescimento dos cordeiros, foram utilizadas 86 ovelhas Bb x Pb (BbPb) e 73 Kat x Dor (KatDOR). Quatro cordeiros Dor x BbPb, seis Dam x BbPb e seis Dam x KatDor foram sacrificados para avaliação de carcaça. MLP foi analisada com o procedimento CATMOD, considerando-se fatores como idade e raça. Dados de crescimento do cordeiro foram analisados com o procedimento MIXED, e as de características de carcaça com o procedimento GLM do SAS, utilizando-se peso ao sacrifício como covariável. MLP foi maior (P<0.05) em Bb do que em Dor. Os cordeiros Dor x BbPb foram mais pesados (P<0.05) no nascimento do que Dam x BbPb. Em partos simples e múltiplos, os cordeiros de ovelhas KatDor foram mais pesados (P<0.05) no momento do nascimento de cordeiros BbPb. As cordeiras de carneiros Dor apresentaram maior (P<0.05) ganho de peso após o desmame do que as de carneiros Dam. O rendimento de carcaça, a espessura da gordura subcutânea e o rendimento de corte primal não foram diferentes por efeito da raça de carneiro. Conclui-se que as ovelhas Bb são mais prolíficas do que as ovelhas Dor; cordeiros de carneiros Damara tiveram resposta de crescimento pós-desmame e rendimento de carcaça semelhantes aos dos carneiros Dor, embora Dorper cordeiras fossem mais pesadas do que as de Damara.
Subject(s)
Animals , Weight Gain , Weaning , Sheep/growth & development , Sheep/genetics , Reproduction/genetics , Litter Size/genetics , Reproductive Physiological Phenomena/geneticsABSTRACT
Profitability of sheep production depends on the reproductive response of ewes and growth of their lambs, which can be improved through the ram genotype. The aim of this study was to evaluate the reproductive response of Blackbelly (Bb), Pelibuey (Pb), Katahdin (Kat) and Dorper (Dor) ewes crossed with Damara (Dam) and Dor rams and the growth of their offspring. To measure percentage of single and multiple lambings (MLP), 234 Bb, Pb, Kat and Dor ewes were used. To measure lamb growth, the offspring of 86 Bb x Pb (BbPb) ewes and 73 Kat x Dor (KatDOR) ewes were used. Four Dor x BbPb, six Dam x BbPb and six Dam x KatDor lambs were slaughtered for carcass assessment. MLP was analyzed with the CATMOD procedure considering the factors age and breed. Lamb growth data were analyzed with the MIXED procedure, and those of carcass characteristics with the GLM procedure of SAS, using weight at slaughter as covariable. MLP was higher (P<0.05) in Bb than in Dor. The Dor x BbPb lambs were heavier (P<0.05) at birth than Dam x BbPb. Of the lambs from single and multiple births, the KatDor lambs were heavier (P<0.05) at birth than BbPb lambs. The female lambs of Dor rams had higher (P<0.05) weight gain after weaning than those of Dam rams. Carcass dressing, subcutaneous fat, and primal cut yield were not different (P>0.05) by effect of ram breed. It is concluded that Bb ewes are more prolific than Dor ewes; male lambs of Dam rams had post-weaning growth response and carcass yield similar to those of Dor rams, although the female lambs of Dor rams were heavier than those of Dam rams.(AU)
Rentabilidade da produção de ovinos depende da resposta reprodutiva de ovelhas e do crescimento de seus cordeiros, o que pode ser melhorado por meio do genótipo masculino. O objetivo deste estudo foi avaliar o desempenho reprodutivo de ovinos Blackbelly (Bb), Pelibuey (Pb), Katadin (Kat) e Dorper (Dor) e o crescimento de cordeiros com carneiros Damara (Dam) e Dor. Para medir a porcentagem de partos simples e múltiplas (MLP), foram utilizados 234 ovelhas Bb, PB, Kat e Dor. Para medir o crescimento dos cordeiros, foram utilizadas 86 ovelhas Bb x Pb (BbPb) e 73 Kat x Dor (KatDOR). Quatro cordeiros Dor x BbPb, seis Dam x BbPb e seis Dam x KatDor foram sacrificados para avaliação de carcaça. MLP foi analisada com o procedimento CATMOD, considerando-se fatores como idade e raça. Dados de crescimento do cordeiro foram analisados com o procedimento MIXED, e as de características de carcaça com o procedimento GLM do SAS, utilizando-se peso ao sacrifício como covariável. MLP foi maior (P<0.05) em Bb do que em Dor. Os cordeiros Dor x BbPb foram mais pesados (P<0.05) no nascimento do que Dam x BbPb. Em partos simples e múltiplos, os cordeiros de ovelhas KatDor foram mais pesados (P<0.05) no momento do nascimento de cordeiros BbPb. As cordeiras de carneiros Dor apresentaram maior (P<0.05) ganho de peso após o desmame do que as de carneiros Dam. O rendimento de carcaça, a espessura da gordura subcutânea e o rendimento de corte primal não foram diferentes por efeito da raça de carneiro. Conclui-se que as ovelhas Bb são mais prolíficas do que as ovelhas Dor; cordeiros de carneiros Damara tiveram resposta de crescimento pós-desmame e rendimento de carcaça semelhantes aos dos carneiros Dor, embora Dorper cordeiras fossem mais pesadas do que as de Damara.(AU)