RESUMO

This study assessed the feasibility of in vivo embryo production and nonsurgical embryo recovery (NSER) in Morada Nova ewes (an endangered native Brazilian breed of sheep) subjected to different estrus synchronization and/or superovulation protocols. Ewes received intravaginal sponges soaked with 60 mg medroxyprogesterone acetate (MAP), which were kept in place for six (G6; n = 12), nine (G9; n = 12), or 12 (G12; n = 12) days. Half of the ewes in each group remained estrus synchronized only (SYNCH) and the other half was superovulated (SOV) with 133 mg porcine follicle-stimulating hormone (pFSH). There were no differences (p > 0.05) in antral follicle counts determined with ultrasonography 60 hours before MAP sponge removal (or at the time of the first pFSH dose) among G6 (6.4 ± 0.9), G9 (6.2 ± 0.7), and G12 (5.5 ± 0.6). Estrus responses and NSER success rates did not vary (p > 0.05) among the three progestin-treatment groups of ewes for either estrus-induced or superovulated animals. The onset of estrus occurred 10-12 hours later (p < 0.01) in G9SYNCH ewes compared with G6SYNCH and G12SYNCH, and the duration of estrus was ∼19 hours greater (p < 0.01) in G9SOV than in G6SOV. The average duration of the NSER procedure was 32.6 ± 1.3 minutes. At least one structure was recovered in 85.7% of synchronized and in 87.5% of superovulated ewes. Viable embryo recovery rates were also similar (p > 0.05) for G6 (1.0 ± 0.3 and 2.5 ± 1.5), G9 (1.3 ± 0.5 and 4.8 ± 2.0), and G12 groups (1.0 ± 0.3 and 4.8 ± 2.3; estrus-synchronized and superovulated ewes, respectively). In conclusion, progestogen pretreatment of different durations and NSER can be employed in Morada Nova ewes, resulting in reasonable viable embryo recovery rates in both estrus-synchronized and superovulated animals. Therefore, both techniques are suitable for use in commercial settings as well as small ruminant conservation programs.

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The present paper aimed to show the thermoregulatory responses of locally adapted Morada Nova sheep with different coat colors that were exposed to direct solar radiation in an equatorial semiarid region. Animals were classified into four groups according to the coat color as follows: (1) dark red, (2) intermediate red, (3) light red, and (4) white coats. Forty Morada Nova ewes were observed in for 7 consecutive months. The experimental variables measured were rectal temperature (RT), skin surface temperature (ST), respiratory rate (RR), skin surface evaporation (CE), respiratory evaporation (RE), and heat exchange by convection (HC) and radiation (R). Data were collected from 1100 to 1400 h after the animals were exposed to 30 min direct sunlight. The results showed that all groups maintained homeothermy. The RR was higher in the animals of groups 1 to 3, which also showed higher values for ST when compared to the white-coated animals. Sensible heat exchange mechanisms were not important for heat loss, and R was a significant source of heat gain from the environment for the animals. Groups 1, 2, and 3 used RR more intensely than group 4 (P value = 0.001); however, CE was higher for the white-coated animals. It was concluded that Morada Nova sheep are well adapted to the semiarid environment, regardless of coat color.

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The aim of this study was to build a prediction model both sensible and latent heat transfer by respiratory tract for Morada Nova sheep under field conditions in a semiarid tropical environment, using easily measured physiological and environmental parameters. Twelve dry Morada Nova ewes with an average of 3 ± 1.2 years old and average body weight of 32.76 ± 3.72 kg were used in a Latin square design 12 × 12 (12 days of records and 12 schedules). Tidal volume, respiratory rate, expired air temperature, and partial vapor pressure of the expired air were obtained from the respiratory facial mask and using a physiological measurement system. Ewes were evaluated from 0700 to 1900 h in each day under shade. A simple nonlinear model to estimate tidal volume as a function of respiratory rate was developed. Equation to estimate the expired air temperature was built, and the ambient air temperature was the best predictor together with relative humidity and ambient vapor pressure. In naturalized Morada Nova sheep, respiratory convection seems to be a mechanism of heat transfer of minor importance even under mild air temperature. Evaporation from the respiratory system increased together with ambient air temperature. At ambient air temperature, up to 35 °C respiratory evaporation accounted 90 % of the total heat lost by respiratory system, on average. Models presented here allow to estimate the heat flow from the respiratory tract for Morada Nova sheep bred in tropical region, using easily measured physiological and environmental traits as respiratory rate, ambient air temperature, and relative humidity.

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Esse trabalho apresenta valores médios, erros padrão e correlações de Pearson de 10 medidas lineares (alturas de cernelha, garupa e tórax; perímetros da canela e torácico; comprimentos da garupa e corporal; abertura de ísquio; largura da garupa; e peso corpóreo) de 14 novilhas Pantaneiras, bem como uma análise multivariada por meio de análise de componentes principais (PCA) para reduzir quantidade de variáveis passíveis de serem mantidas e utilizadas em seleção, por apresentar maior contribuição para variação total. Os animais, com idade de 36 meses, não prenhes, pertencem ao Núcleo de Bovinos Pantaneiros de Aquidauana, da Universidade Estadual de Mato Grosso do Sul. As novilhas apresentaram medidas próximas aos bovinos de pequeno porte, como as raças Jersey e Sindi, com peso médio de 375±10Kg. O peso corpóreo apresentou correlação de magnitude moderada e significativa (P 0,05) com as alturas de cernelha (55%) e garupa (69%) e com o comprimento corporal (59%); e alta com perímetro torácico (82%). Nesse sentido, ao escolher exemplares mais altos, compridos e com maior garupa e circunferência torácica, certamente se estará selecionando animais mais pesados. Com base no peso das medidas, foram necessários apenas 4 PCA com autovalor mínimo de 1,0, acumulando 83,95% da variância acumulada. Extraiu-se 1 característica com maior peso em cada PCA, passível de ser mantida em estudos futuros ou em programas de seleção, havendo redução de 60%; sendo assim, indicam-se as medidas de altura e largura de garupa, perímetro torácico e comprimento corporal, como sendo essenciais para a escolha de animais fenotipicamente superiores.

This paper exhibit average values, standard error and Pearson correlations of 10 linear measurements (withers, rump and thorax height; shin and thoracic perimeters; rump and body lengths; opening of ischium; breadth of the rump, and body weight) of 14 heifers Pantaneira breed, as well as a multivariate analysis using principal component analysis (PCA) to reduce the amount of variables that can be kept and used in selection, due to a higher contribution to the total variation. The animals, with 36 months, not pregnant, belong to Nucleus of Cattle Pantaneiros of Aquidauana, University State of Mato Grosso do Sul. The heifers presented measures near the small sized cattle, such as Sindhi and Jersey breeds, with weight of 375±9.95kg. The body weight showed a moderate correlation and significant (P 0.05) with withers (55%) and rump heights (69%) and body length (59%), and high thoracic perimeter (82%). Therefore, by choosing the highest exemplary, of longer and greater rump and thoracic circumference, certainly will be selected the heavier animals. Based on the weight of the measures were needed only 4 PCA with minimum autovalue of 1.0, reaching 83.95% of the cumulative variance. It was extracted 1 characteristic with the highest weight in each PCA, which may be maintained in future studies or screening programs, with a reduction of 60%, thus, indicating the measurements of height and breadth of the rump, thoracic perimeters and length body as being essential to select of animals phenotypically superior.

Assuntos

RESUMO

Esse trabalho apresenta valores médios, erros padrão e correlações de Pearson de 10 medidas lineares (alturas de cernelha, garupa e tórax; perímetros da canela e torácico; comprimentos da garupa e corporal; abertura de ísquio; largura da garupa; e peso corpóreo) de 14 novilhas Pantaneiras, bem como uma análise multivariada por meio de análise de componentes principais (PCA) para reduzir quantidade de variáveis passíveis de serem mantidas e utilizadas em seleção, por apresentar maior contribuição para variação total. Os animais, com idade de 36 meses, não prenhes, pertencem ao Núcleo de Bovinos Pantaneiros de Aquidauana, da Universidade Estadual de Mato Grosso do Sul. As novilhas apresentaram medidas próximas aos bovinos de pequeno porte, como as raças Jersey e Sindi, com peso médio de 375±10Kg. O peso corpóreo apresentou correlação de magnitude moderada e significativa (P 0,05) com as alturas de cernelha (55%) e garupa (69%) e com o comprimento corporal (59%); e alta com perímetro torácico (82%). Nesse sentido, ao escolher exemplares mais altos, compridos e com maior garupa e circunferência torácica, certamente se estará selecionando animais mais pesados. Com base no peso das medidas, foram necessários apenas 4 PCA com autovalor mínimo de 1,0, acumulando 83,95% da variância acumulada. Extraiu-se 1 característica com maior peso em cada PCA, passível de ser mantida em estudos futuros ou em programas de seleção, havendo redução de 60%; sendo assim, indicam-se as medidas de altura e largura de garupa, perímetro torácico e comprimento corporal, como sendo essenciais para a escolha de animais fenotipicamente superiores.(AU)

This paper exhibit average values, standard error and Pearson correlations of 10 linear measurements (withers, rump and thorax height; shin and thoracic perimeters; rump and body lengths; opening of ischium; breadth of the rump, and body weight) of 14 heifers Pantaneira breed, as well as a multivariate analysis using principal component analysis (PCA) to reduce the amount of variables that can be kept and used in selection, due to a higher contribution to the total variation. The animals, with 36 months, not pregnant, belong to Nucleus of Cattle Pantaneiros of Aquidauana, University State of Mato Grosso do Sul. The heifers presented measures near the small sized cattle, such as Sindhi and Jersey breeds, with weight of 375±9.95kg. The body weight showed a moderate correlation and significant (P 0.05) with withers (55%) and rump heights (69%) and body length (59%), and high thoracic perimeter (82%). Therefore, by choosing the highest exemplary, of longer and greater rump and thoracic circumference, certainly will be selected the heavier animals. Based on the weight of the measures were needed only 4 PCA with minimum autovalue of 1.0, reaching 83.95% of the cumulative variance. It was extracted 1 characteristic with the highest weight in each PCA, which may be maintained in future studies or screening programs, with a reduction of 60%, thus, indicating the measurements of height and breadth of the rump, thoracic perimeters and length body as being essential to select of animals phenotypically superior.(AU)

Assuntos

RESUMO

Naturalized Brazilian hair breeds are adapted to tropical climate, however produce lambs for slaughter with lower performance and carcass traits. One way to increase productiveness comprises the use of adapted ewes crossed with specialized meat breeds, exploiting the complementarity between breeds and heterosis for sustainable lamb production. Dorper rams can be use to produce crossbred lambs with better performance traits. The aim of this study was to evaluate the weight at birth and at 30 days of Morada Nova lambs (MN) and Santa Inês (SI) straight breed or Dorper crossbred. The study was carried out at Instituto de Zootecnia, city of Nova Odessa, located in São Paulo State, Brazil. Forty-two adult Santa Inês (SI) ewes with 51.8 ± 7.1 Kg of initial body weight, with 21 mated with SI rams and 21 mated with Dorper (DO) rams and 38  Morada Nova (MN) with 33.1 ± 4.98 with 19 mated with MN and  19 mated with DO rams were used. During pregnancy the ewes were reared on intensive grazing systems with rotational grazing on Aruana grass (Panicum maximum cv. Aruana), plus corn silage ad libitum and a concentrate mixture (400 g/day) with 16% crude protein and 80% of total digestible nutrient (TDN) on  final third of gestation. After lambing, the ewes were kept in collective pens and kept under the same diet used in late pregnancy. The weight at birth as well as at 30 day old were recorded

O artigo não apresenta resumo em português.

RESUMO

Naturalized Brazilian hair breeds are adapted to tropical climate, however produce lambs for slaughter with lower performance and carcass traits. One way to increase productiveness comprises the use of adapted ewes crossed with specialized meat breeds, exploiting the complementarity between breeds and heterosis for sustainable lamb production. Dorper rams can be use to produce crossbred lambs with better performance traits. The aim of this study was to evaluate the weight at birth and at 30 days of Morada Nova lambs (MN) and Santa Inês (SI) straight breed or Dorper crossbred. The study was carried out at Instituto de Zootecnia, city of Nova Odessa, located in São Paulo State, Brazil. Forty-two adult Santa Inês (SI) ewes with 51.8 ± 7.1 Kg of initial body weight, with 21 mated with SI rams and 21 mated with Dorper (DO) rams and 38  Morada Nova (MN) with 33.1 ± 4.98 with 19 mated with MN and  19 mated with DO rams were used. During pregnancy the ewes were reared on intensive grazing systems with rotational grazing on Aruana grass (Panicum maximum cv. Aruana), plus corn silage ad libitum and a concentrate mixture (400 g/day) with 16% crude protein and 80% of total digestible nutrient (TDN) on  final third of gestation. After lambing, the ewes were kept in collective pens and kept under the same diet used in late pregnancy. The weight at birth as well as at 30 day old were recorded

O artigo não apresenta resumo em português.