The phosphorus requirement of pregnant sheep

Sykes, Andrew G.; Dingwall, R

doi:10.1017/s0021859600061141

Cited by 10 publications

(9 citation statements)

References 27 publications

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“…If this assumption is correct, then endogenous faecal loss of P should remain at this low level, irrespective of P intake, providing animals are fed just enough P to meet their requirements. Although low endogenous faecal losses of P have been observed in sheep given semi-purified diets deficient in P (Sykes & Dingwall, 1976) or very poor natural diets (Field, Sykes & Gunn, 1974) and there is some evidence that the high endogenous faecal loss associated with high P intakes can be reduced in response to an increased P demand (present study; Braithwaite, 19836) or an infusion of Ca into the blood (Braithwaite, 1984), there is yet no firm evidence that the endogenous loss in animals fed according to requirements can be kept constant at this low level. Rather, it seems more likely that the inevitable endogenous faecal loss, and hence maintenance requirement, must increase to some extent with increased P intake.…”

Section: Resultsmentioning

confidence: 99%

Some observations on phosphorus homoeostasis and requirements of sheep

Braithwaite¹

1984

J. Agric. Sci.

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The results of phosphorus kinetic studies from 149 sheep used in previous studies of calcium and P metabolism have been analysed statistically, to provide information on the mechanism of control of P homoeostasis.Whereas the rate of absorption of dietary P was increased in direct relation to P intake, the efficiency of absorption was decreased. Both the rate and efficiency of absorption, however, were increased in response to increased P demands. These results suggest that P may be absorbed by two processes: a passive one, related to P intake, and an active one, related to P demands.Endogenous loss of P in the faeces was directly related to both P intake and P absorption bat inversely related to P demands. Salivary secretion of P was directly related to P absorption and increased at a rate of 1 mg/day/kg body weight for each 1 mg/day/kg body weight increase in absorption. This finding supports the suggestion that the inevitable endogenous faecal loss of P, in animals fed exactly according to their P requirements, is not constant but varies in direct relation to the rate of P absorption, and hence to the P intake needed to supply these requirements.Urinary loss of P was generally low, but high values were found in some animals and were associated with increased rates of P absorption and decreased rates of endogenous faecal loss of P. Possible reasons for these high rates of urinary P are discussed.Increased P demands were met by a combination of an increase in P absorption and a decrease in endogenous faecal loss of P, and P retention was directly related to Ca retention.The relevance of these results to the calculation of P requirements and to the control of P homoeostasis is discussed.149 results are available from animals in various physiological states and given a variety of treatComparable recommendations by the Agri-ments. The purpose of this paper is to provide, by cultural Research Council (1965Council ( , 1980, the Nation-statistical analysis of these 149 results, information al Research Council (1968Council ( , 1975 and the Institut which may be useful in the calculation of P recomNational de la Recherche Agronomique (1978) for mendations and, at the same time, help improve the phosphorus requirements of sheep and cows at our understanding of the control of P homoeodifferent stages of growth, pregnancy and lactation stasis. can vary by as much as two-fold (Field, 1981; MATERIALS AND METHODS Braithwaite, 19836). This variation is due partly to different interpretation by these three bodies of Male and female sheep, ranging from 2 to 5 years the relevant information on P metabolism and of age, in various physiological states and given a partly to a general lack of this information.variety of different treatments were used in these During the past 5 years, an intensive study of studies of Ca and P metabolism. In particular, calcium and P metabolism of sheep has been studies were performed at different stages of pregcarried out at the National Institute for Research nancy and lactation and treatments inclu...

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Section: Resultsmentioning

confidence: 99%

Some observations on phosphorus homoeostasis and requirements of sheep

Braithwaite¹

1984

J. Agric. Sci.

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“…Digestibility SYKES and COOP (1976) found in continuous infections of lambs with Trichostrongvltrs coltrbrifrmis, a small intestinal parasite, n o reduction in digestibility. The same authors (SYKES and COOP 1977) found a depressed protein digestibility in lambs continuously infected with Ostertagia circumcincta, an abomasal parasite. This was found in comparison to pair fed animals.…”

Section: Discussionmentioning

confidence: 79%

“…Reduced performance may be due to a lowered digestive efficiency of the parasitized gastro-intestinal tract, resulting in lower apparent digestibility o f the ration as found by BREMNER (1961) and SYKES and COOP (1977). However, in other studies such a change in digestibility was not observed (SYKES and COOP 1976;ROSEBY 1977;POPPI et al 1981). Absorbed nutrients may be used less efficiently by infected animals.…”

Section: Introductionmentioning

confidence: 80%

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Effect of trichostrongylid infection on feed intake, metabolic rate and protein gain of calves

Verstegen

Hel

Albers

et al. 1988

Animal Physiology Nutrition

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Zusammenfassung Der Einfluß einer Trichostrongyliden‐Infektion auf die Futteraufnahme, den Energieumsatz und Proteinansatz bei Kälbern In zwei Versuchen wurde an 3 bis 6 Monate alten Kälbern der Einfluß einer Trichostrongyliden‐Infektion auf den Energie‐ und Proteinumsatz gemessen. Im 1. Versuch mit acht männlichen Friesian‐Kälbern wurden 4 Kälber mit 20000 infektiösen Cooperia spp‐Larven infiziert. Sieben Wochen später erhielten die Kälber erneut 350000 infektiöse Larven. 10 bis 40 Tage nach der 2. Infektion wurden Energie‐ und Proteinstoffwechsel untersucht, mit Hilfe indirekter Kalorimetrie. Im 2. Versuch wurden 8 Kälber mit 100000 Cooperia spp‐Larven infiziert und nach 4 und 5 Wochen mit Thiabendazol behandelt. Ab der 17. Lebenswoche wurden vier Tiere dreimal in der Woche über insgesamt 8 Wochen mit 2 500 Ostertagia sp‐Larven und 25 000 Cooperia sp‐Larven reinfiziert. Diese Tiere wurden pair‐fed mit Kontrolltieren gefüttert. Der Energie‐ und Proteinumsatz wurde über 8 Wochen gemessen. Die Kontrolltiere zeigten eine um 370 g/Tag höhere Zunahme als die infizierten Tiere in Versuch 1 und eine um 75 g/Tag höhere Zunahme als die infizierten Tiere in Versuch 2. Die Umsetzbarkeit der Energie lag bei den infizierten niedriger als bei den nicht infizierten. Der Energieaufwand für Erhaltung lag bei den infizierten Tieren höher als bei den Kontrolltieren. Bei geringerer Rauhfutterzufuhr (Versuch 1) war der Erhaltungsbedarf für infizierte Tiere im Vergleich zu den Kontrollen nicht erhöht. Außerdem wurde festgestellt, daß bei geringerem Gewichtszuwachs ein niedrigerer Proteinansatz bei den infizierten Tieren zu verzeichnen war.

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“…The non-lactating cows were used in only one trial (4 animals) for the study of the relationship between phosphorus and calcium absorption and their concentration in the diet [28]. The only pregnant animals of our database were ewes used in 4 trials (64 animals) and weighing 46 kg [29], 50 kg [26], 65 kg [30], and 70 kg [27]. The lactating ewes ingested 859 g DM and weighed on average 59.6 kg.…”

Section: General Resultsmentioning

confidence: 99%

I. A bibliographic database for quantitative analysisof phosphorus flow in ruminants

Bravo

Sauvant

Bogaert³

et al. 2003

Reprod. Nutr. Dev.

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-The present study describes a quantitative analysis of phosphorus metabolism in ruminants. The database compiles 100 sources either published (95) or unpublished (5) involving studies on true or apparent phosphorus balances carried out before 1999. The database reports 652 distinct experimental conditions (lines) described with experimental variables (column) involving a total of 2 982 animals: 414 lambs (33 references), 1 078 sheep (37 references), 64 pregnant ewes (3 references), 212 lactating ewes (5 references), 528 calves (20 references), 4 maintenance cows (1 reference), 519 lactating cows (6 references), 42 kids (1 reference) and 121 lactating goats (3 references). The reliability of the database was tested using some general relationships.metabolism / phosphorus / quantitative aspect / ruminant

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The phosphorus requirement of pregnant sheep

Cited by 10 publications

References 27 publications

Some observations on phosphorus homoeostasis and requirements of sheep

Some observations on phosphorus homoeostasis and requirements of sheep

Effect of trichostrongylid infection on feed intake, metabolic rate and protein gain of calves

I. A bibliographic database for quantitative analysisof phosphorus flow in ruminants

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