A Description of the Dynamics of Fetal Growth in Sheep

Koong, L. J.; Garrett, W. N.; Rattray, P. V.

doi:10.2527/jas1975.4141065x

Cited by 67 publications

(45 citation statements)

References 2 publications

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“…Glucose infusion produced no alteration in umbilical blood flow from the basal value of 232±7 ml/kg per min (828±25 ml/min 186±7 (8) 69±3 (8) 30±3 (8) 0.19±0.03 (8) 0.14±0.02 (8) Day 1 394±34 (7) 219±11 (8) 203±11 (8) 70±5 (7) 29±2 (8) 0.19±0.03 (7) 0.13±0.02 (7) Day 2 396±37 (7) 223±13 (8) 197±10 (8) 67±4 (7) 31±3 (7) 0.18±0.03 (7) 0.14±0.02 (6) Day 3 416±67 (5) 241±15 (7) 197±12 (7) 71±4 (5) 32±3 (5) 0.20±0.05 (5) 0.13±0.01 (6) ut, uterine; umb, umbilical. *, ( ), number of observations.…”

Section: Resultsmentioning

confidence: 99%

“…Fetal weight increases by -2-4%/d in late gestation (8) and some, but not proportionate, increases in fetal oxygen consumption (expressed as ml/min) also occur after 120-130-d gestation (9,10 were withdrawn into capillary tubes pretreated with NaF. Plasma antipyrine concentrations were determined using the Technicon Autoanalyzer (Technicon Instruments Corp., Tarrytown, NY).…”

Section: Methodsmentioning

confidence: 99%

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Effects of chronic fetal hyperglycemia upon oxygen consumption in the ovine uterus and conceptus.

Philipps¹,

Porte²,

Stabinsky³

et al. 1984

J. Clin. Invest.

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Abstra ct. Hyperglycemia has been shown to induce arterial hypoxemia in the chronically catheterized fetal sheep. To investigate the mechanism behind this glucose-induced hypoxemia, eight pregnant ewes and their fetuses were studied. Fetal glucose infusion (1 1.9±0.6 mg glucose/kg per min) was associated with a doubling of the fetal plasma glucose concentration with concomitant elevation of the umbilical vein-distal arterial 02 content difference by 24 h of infusion (P < 0.01). Calculated fetal 02 consumption increased from 8.1±0.4 ml/kg per min in the control period to a maximum value of 10.6±0.3 ml/kg per min by third infusion day (P < 0.01), which is an increase of -30%. The degree of stimulation of fetal 02 consumption was related to the degree of fetal hyperglycemia but not to the degree of fetal hyperinsulinemia. The increase in fetal 02 consumption was accompanied by a significant increase in fetal 02 extraction with no change in either fetal 02 delivery or fetal blood 02 affinity. In addition, fetal hypercapnea with a mild fetal respiratory acidosis was induced by fetal hyperglycemia. The increase in fetal arterial Pco2 was linearly related (P < 0.001) to the magnitude of increase in fetal 02 consumption. These studies suggest that chronic fetal hyperglycemia induces a state ofaccelerated fetal oxidative metabolism and may be important in explaining the etiology behind certain unusual findings in human infants of diabetic mothers.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Effects of chronic fetal hyperglycemia upon oxygen consumption in the ovine uterus and conceptus.

Philipps¹,

Porte²,

Stabinsky³

et al. 1984

J. Clin. Invest.

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“…Furthermore, the birth weights of lambs for the ewes shorn at housing and from ewes extended grazed were similar, indicating that reduced heat stress was responsible for the increased birth weight of lambs from the ewes shorn at housing. concluded that, using the equations of Koong et al (1975) and Robinson et al (1977) for foetal growth prior to birth, increasing gestation length from 145.8 to 147.5 days would account for proportionately 0.23 and 0.35, respectively, of the increased birth weight of the lambs from the shorn ewes. The increased forage intake (0.18), due to winter shearing, throughout the housing period was the equivalent of increased ME intake of 111 MJ.…”

Section: Effects Of Winter Shearingmentioning

confidence: 99%

Effects of shearing at housing, grass silage feed value and extended grazing herbage allowance on ewe and subsequent lamb performance

Keady

Hanrahan

2009

Animal

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The study involved 120 crossbred ewes (sixty 1.5 years old animals and sixty 2.5 years old animals; initial liveweight 67.6 kg, condition score 3.7), that were mated in October. They were assigned to six treatments (two shearing treatments (shorn and unshorn) 3 two silage feed values (low and medium) and two extended grazed herbage allowances (1.0 and 1.8 kg dry matter (DM)/day)) designed to evaluate the effects of shearing at housing, grass silage feed value and extended-grazed herbage allowance on their performance and the performance of their progeny. Swards, which had silage harvested on 6 September, received fertiliser N (34 kg/ha) for extended (deferred) grazing between 19 December and lambing in mid-March. The herbage was allocated at DM allowances of 1.0 or 1.8 kg/ewe daily until 1 February. For the final 6 weeks of pregnancy, daily herbage DM allowances were 1.5, 1.6, 2.0, 2.0 and 2.0 kg for weeks 6, 5, 4, 3 and 2 to parturition, respectively. Two grass silages (low and medium feed value) were offered from housing on 19 December to lambing in mid-March. At housing, half the ewes were shorn whilst the remainder remained unshorn. Each ewe received 23.4 kg concentrate prior to lambing. For the extended-grazed herbage and the low and medium feed-value silages, DM concentrations were 132, 225 and 265 g/kg, and metabolisable energy (ME) concentrations were 10.0, 10.0 and 10.7 MJ/kg DM, respectively. Treatment did not alter (P . 0.05) litter size or number reared. Grass silage feed value did not significantly alter silage DM intake, or ewe and subsequent lamb performance. Increasing herbage allowance in mid-pregnancy decreased herbage utilisation (P , 0.05) and increased herbage intake (P , 0.05). Shearing increased silage intake (P , 0.05), lamb birth weight (P , 0.01) and tended to increase lamb weaning weight (P 5 0.07). Relative to the housed shorn ewes, extended grazing did not alter (P . 0.05) ewe or subsequent lamb performance. It is concluded that shearing ewes at housing increased lamb birth weight due to increased silage intake probably associated with cold stress immediately post shearing and reduced heat stress in late pregnancy. Based on differences in lamb weight at weaning 0.8 kg of grass silage DM intake had the same feed value as a daily extended herbage DM allowance of 1.8 kg per ewe throughout the study. Neither silage feed value nor herbage allowance in mid-pregnancy affected lamb birth weight or subsequent growth rate.

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“…Já o Modelo 2 é comumente utilizado para descrever a dinâmica do desenvolvimento fetal em ovinos (Koong et al, 1975).…”

Section: Resultsunclassified

Utilização de modelos matemáticos para estimar a retenção de minerais em cabras durante a gestação

et al. 2003

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RESUMO -O trabalho foi realizado com o objetivo de estimar a retenção de elementos minerais durante a gestação de cabras com um ou dois fetos, utilizando-se diferentes modelos matemáticos. A estimativa de retenção foi baseada na diferença entre o total de cada mineral depositado no feto, útero, membranas, fluídos fetais e glândula mamária dos animais nas diferentes etapas da gestação e o total de cada mineral armazenado nas cabras vazias, utilizando-se os modelos de predição: ln Y = A -B e -C X ; Y = A e B X e ln Y = A + Bx + Cx 2 , em que x = tempo de gestação. Comparando-se a estimativa com os valores reais obtidos, verificou-se que o modelo proposto ln = A+Bx+Cx 2 , explicou com coerência e precisão o comportamento biológico da retenção de minerais durante todas as fases da gestação.Palavras-chave: cabras, gestação, minerais, retenção de minerais Utilization of Mathematic Models to Estimate the Minerals Retention during the Pregnancy of GoatsABSTRACT -This work was carried out with the purpose to evaluate the minerals retention during the pregnancy of goats with one or two foetus. The estimate of retention was based in the difference between the total of each mineral stored in the foetus, uterus, membranes, fetals fluids and mammary gland of animals in the differents stages of pregnancy and the total of each mineral stored in the Key Words: goats, pregnancy, minerals, minerals retention 1 Parte da tese apresentada pelo primeiro autor ao Doutorado em Zootecnia da FCAV-UNESP, Campus de Jaboticabal-SP. 2 Departamento de Agropecuária do Campus IV da UFPB, Bananeiras-PB, CEP 58.220-000. E.mail: rgermano@cft.ufpb.br 3 Departamento de Zootecnia da FCAV/UNESP, Campus de Jaboticabal-SP, CEP 14.870-000. 4 Departamento de Zootecnia da UFV, Viçosa-MG. CEP: 36.570-000 IntroduçãoOs minerais representam um componente essencial para a dieta dos caprinos e influenciam de modo marcante a sua produtividade, podendo em alguns casos ou regiões com solos deficientes, ser limitantes econômica e biologicamente e afetar inclusive a sobrevivência do animal. Durante a gestação, o nível nutricional tem extrema importância, sobretudo nos últimos 45 dias, quando os tecidos fetais têm maior desenvolvimento (Kadu & Kaikini, 1987). Se os nutrientes não forem suficientes nas últimas semanas que antecedem o parto, a concorrência entre mãe e feto poderá levar ao aborto.A gestação é uma fase importante na vida das fêmeas, já que as transformações que ocorrem afetam não somente o aparelho reprodutivo, mas todo o organismo animal. O metabolismo da mãe sofre profundas modificações, pois deve prover o feto de todos os princípios nutritivos em quantidades suficientes, embora haja, durante a gestação, uma notável melhoria nos processos de absorção do conduto alimentício, particularmente na assimilação de substâncias minerais.O ARC (1980) recomenda que para se calcular as quantidades de nutrientes depositadas no útero grávido, em sucessivos estádios da gestação, faz-se necessário conhecer: a quantidade total de nutrientes no feto; a quantidade adicion...

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A Description of the Dynamics of Fetal Growth in Sheep

Cited by 67 publications

References 2 publications

Effects of chronic fetal hyperglycemia upon oxygen consumption in the ovine uterus and conceptus.

Effects of chronic fetal hyperglycemia upon oxygen consumption in the ovine uterus and conceptus.

Effects of shearing at housing, grass silage feed value and extended grazing herbage allowance on ewe and subsequent lamb performance

Utilização de modelos matemáticos para estimar a retenção de minerais em cabras durante a gestação

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