Studies on the energy metabolism of the pregnant sow

Close, W. H.; Noblet, Jean; Heavens, R.P.

doi:10.1079/bjn19850034

Cited by 82 publications

(13 citation statements)

References 27 publications

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“…Most authors report no significant difference between maintenance requirement for ME (MEm) for pregnant and dry sows (e.g. Close et al, 1985, Noblet et al, 1997), when expressed per kg metabolic live weight (LW). Obviously, the LW was more important for the total maintenance requirement than the reproductive stage.…”

Section: Discussionmentioning

confidence: 99%

Energy and protein metabolism in pregnant sows fed two levels of dietary protein

Theil¹,

Jørgensen²,

Jakobsen³

2002

Animal Physiology Nutrition

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The present study was performed to quantify the energy and nutrient metabolism of pregnant sows fed high (HP) or low (LP) dietary protein [18.3 vs. 13.5% of dry matter (DM)]. A total of nine sows (four on HP and five on LP diet) were subjected to balance and respiration trials four times during their second pregnancy (approximately on days 30, 61, 80 and 104 of gestation). The digestibility of protein (83.0 vs. 79.9) (p < 0.01) and energy (84.9 vs. 83.7%) (p < 0.05) was higher for the HP diet. Daily intake of metabolizable energy (ME) and retained energy (RE) were similar for the two groups, with an average of 28.37 MJ ME and 3.94 MJ RE, respectively. Heat production (HE) measured according to the respiratory quotient (RQ) and carbon-nitrogen (CN) method was similar (464 vs. 454 kJ/kg 0.75/day, respectively). Sows fed HP retained more energy in protein (3.33 vs. 2.00 MJ/day) (p < 0.001) and tended to retain less energy in fat (1.59 vs. 2.50 MJ/day) than LP sows. Retained nitrogen (N) (22.3 vs. 13.4 g/day) (p < 0.001) and utilization of N (retained/digested) (45.2 vs. 38.1%) was higher for HP sows compared with LP sows. In late pregnancy, retained N, retained fat, HE and oxidation of carbohydrates increased, while oxidation of fat was reduced to zero. In conclusion, both diets provided adequate N for retention in maternal tissue and conception products. In spite of the lower utilization of N in LP sows, the N excretion was depressed by 5.6 g/day compared with HP sows, because of the lower N intake.

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Section: Discussionmentioning

confidence: 99%

Energy and protein metabolism in pregnant sows fed two levels of dietary protein

Theil¹,

Jørgensen²,

Jakobsen³

2002

Animal Physiology Nutrition

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“…Following habituation the animals were removed to a specially-designed heat-sink calorimeter (Close et al 1978) maintained at 20 (SE 0.5)". Each animal remained in the calorimeter for 7 d when its heat loss and energy and nitrogen balances were determined (Close et al 1985). At the end of the calorimetric period the animals, both pregnant and control, were weighed and slaughtered and their uterus and mammary tracts removed for subsequent chemical analysis.…”

Section: Experimental Designmentioning

confidence: 99%

“…If it is assumed that energy is accreted with an efficiency of 0.80 (Agricultural Research Council, 1981), it may be calculated that as pregnancy progresses from day 50 to day 110, the ME requirement for reproductive gain increases from 0.03 to 0.12 of maternal energy intake. The corresponding values for protein have been calculated on the basis that the digestibility of protein is 0-74 (Close et al 1985) and that the efficiency with which protein is utilized is 0.70 (Ferrell et al 1976;Agricultural Research Council, 198 1). The calculated requirement for protein as a proportion of intake is greater than that of energy, increasing from 0.07 of maternal digestible protein intake at day 50 of gestation of 0.41 at day 110.…”

Section: Mammary Tissuementioning

confidence: 99%

Studies on the energy metabolism of the pregnant sow

et al. 1985

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1. Twenty-six gilts were used in an experiment to study the effects of level of feed intake on the growth and chemical composition of the gravid uterus and mammary tissue at several stages of gestation. The animals were given either 1.8 or 2.5 kg feed/d (20 or 30 MJ metabolizable energy (ME) respectively) and were slaughtered at intervals between days 40 and 110 of gestation. The gravid uterus was dissected into fetal, placental, fluid and empty uterus components. From day 70 of gestation the mammary tissue was also dissected. The fresh weight and dry matter (DM), energy and nitrogen contents of the various tissues were determined.2. (a) With the exception of the fluid component, there was a significant increase ( P < 0.01) in the fresh weight of each tissue with both stage of gestation and level of feeding. At comparable litter sizes the total weight of the fetuses in late gestation was 16% higher with the higher feed intake. (b) The DM content of the individual uterine tissues increased significantly ( P < 0.01) with increase in stage of gestation so that the mean DM content of the gravid uterus increased from 74.6g/kg at day 50 to 103.1 and 159,0g/kg at days 90 and 110 of gestation respectively. (c) Neither stage of gestation nor feeding level influenced the respective energy contents of the individual uterine tissues, when expressed per g DM. The mean energy content of the total gravid uterus was 19.5 kJ/g DM. (d) The N content (g/g fresh weight) of the tissues increased with stage of gestation and was generally higher at the higher feeding level. The mean N contents (g/g DM) of the fetal, placental, fluid and empty uterine tissues were 0.090, 0,101, 0.098 and 0.128 respectively.3. The mammary tissue was the most variable of all the tissues investigated. Whereas the fresh weight and N content increased with stage of gestation, both the DM and energy content decreased. 4.Gompertz equations were fitted to describe the effects of stage of gestation, level of feed intake and litter size on the fresh weight and chemical content of the individual uterine tissues, total gravid uterus and mammary tissue. The use of these equations for calculating the nutrient requirements of pregnancy is demonstrated.5. It was calculated that between days 50 and 110 of gestation the ME requirement for reproduction increased from 3 to 12% of maternal energy intake. The calculated requirement for protein was from 7 to 41 % of maternal dietary protein intake respectively.In order to predict the nutrient requirements throughout pregnancy, it is necessary to know the changes which occur in both the reproductive and maternal tissues. In the past, the nutrient requirements of the pregnant sow have been based on an empirical approach by which reproductive characteristics such as sow-weight gain, litter size and average birth weight of the piglets have been assessed in relation to various nutritional inputs (e.g. Agricultural Research Council, 1967 (1976). These results describe only the extent to which the fetal and other reproductive tiss...

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“…Thus the above values for net efficiency are values for the combined efficiencies of energy deposited in the two compartments. Recently, Close et al (10) reported that the net efficiency for energy deposition in the reproductive tissues was 72%. This value was calculated from the partition of total energy retention into net maternal and reproductive components (protein and fat).…”

Section: Discussionmentioning

confidence: 99%

Maintenance energy requirement in pregnant rats and net energetic efficiency for fetal growth during late pregnancy.

Imai

Ohnaka

Ondani

et al. 1986

Journal of Nutritional Science and Vitaminology, J Nutr Sci Vit

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SummaryThe maintenance energy requirement (MEm) of pregnant rats and net energetic efficiency for fetal growth during late pregnancy were examined by regression analysis. Pregnant rats, weighing about 180 g, were fed on 20% casein diet during early-mid pregnancy and then divided into three groups ad libitum-fed, 50% food restricted, or starved. A linear relation between the energy balance (Y, kcal/100g BW/day) and the metabolizable energy intake (X, kcal/100g BW/day) was obtained as Y=0.81 X-14.83 (n: 17, r=+0.99, p<0.001).The X intercept, MEm, was calculated to be 18.31kcal/100g BW/day. Pregnant animals fed ad libitum retained 6.1 and 1.1 kcal of energy daily in their conceptuses and their own body, respectively, during late pregnancy. Assuming that the net efficiency of maternal energy deposition is equal to that for size and age-matched nonpregnant rats, the net energetic efficiency for fetal growth was calculated to be 82%. This value was very close to the net efficiency for weanling rats reported previously, suggesting that the net energetic efficiency for maximum growth in well-nourished rats is about 82%.

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Studies on the energy metabolism of the pregnant sow

Cited by 82 publications

References 27 publications

Energy and protein metabolism in pregnant sows fed two levels of dietary protein

Energy and protein metabolism in pregnant sows fed two levels of dietary protein

Studies on the energy metabolism of the pregnant sow

Maintenance energy requirement in pregnant rats and net energetic efficiency for fetal growth during late pregnancy.

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