Estimation of the isoleucine and aromatic amino acid requirements of pregnant swine.

Speer, V. C.; Kile, D L; Trew, James Curtis

doi:10.2527/1990.6882394x

Cited by 4 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In most animal species, L-tyrosine can satisfy about 50 % of the total requirements for two aromatic amino acids: L-phenylalanine and L-tyrosine (e.g. Sasse and Baker, 1972;Robbins and Baker, 1977;Anderson et al, 1980;National Research Council (NRC), 1998 1985;Speer et al, 1990;NRC, 1994NRC, , 1998NRC, , 2006. L-Tyrosine and L-phenylalanine are among the most abundant amino acids in cereal-/soybean-based diets (about 1.4 % L-phenylalanine + L-tyrosine; NRC, 1998).…”

Section: Efficacymentioning

confidence: 99%

“…Sasse and Baker, 1972;Robbins and Baker, 1977;Anderson et al, 1980;National Research Council (NRC), 1998). Dietary L-phenylalanine and Ltyrosine requirements, as a percentage of complete feed, are in the range 1.06-1.25 for piglets (5-20 kg bw), 0.55-0.87 for grower/finisher pigs, 0.48-0.54 for pregnant sows, 0.75-1.14 for lactating sows, 0.69-1.04 for laying hens, 1.04-1.34 for chickens for fattening, 0.8-1.8 for turkeys and are around 1.04 for growing dogs, 0.59 for adult dogs and 1.53 for growing cats (Leilis and Speer 1985;Speer et al, 1990;NRC, 1994NRC, , 1998NRC, , 2006. L-Tyrosine and L-phenylalanine are among the most abundant amino acids in cereal-/soybean-based diets (about 1.4 % L-phenylalanine + L-tyrosine; NRC, 1998).…”

Section: Efficacymentioning

confidence: 99%

See 1 more Smart Citation

Scientific opinion on the safety and efficacy of L‐tyrosine for all animal species

2013

EFS2

View full text Add to dashboard Cite

L-Tyrosine can be synthesised in the body from L-phenylalanine, an essential amino acid. The additive L-tyrosine is produced by acid hydrolysis of feather keratin. L-Tyrosine is considered safe for all animal species, provided that the conditions of use are respected, i.e. supplementation of conventional diets with 0.5 % L-tyrosine for food-producing animals and 1.5 % for non-food-producing species. Higher dietary concentrations may lead to growth rate depression and eye lesions, and, in young animals, behavioural changes. L-Tyrosine will be incorporated into the body protein of the animal. The protein composition will not be changed. Free L-tyrosine will not be stored in the tissues. On the basis of the data available, no risk is expected for the consumer from the use of this L-tyrosine preparation showing a purity > 95 %. In the absence of data, the product is considered potentially irritating to skin and eyes, a potential dermal sensitiser and hazardous by inhalation. The use of Ltyrosine in animal nutrition would not be expected to lead to any localised increase in the concentration of Ltyrosine or its metabolites in the environment. It is concluded that the use of this product as a feed additive does not represent a risk to the environment. The supplementation of feed with L-tyrosine is efficacious in cases where high requirements for tyrosine as a melanin precursor occur. This has been demonstrated in cats for intensively colouring the coat. L-Tyrosine may also have the potential to intensify the pigmentation of the coat/plumage of other species, but limited evidence is available. SUMMARYFollowing a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety and efficacy of L-tyrosine for all animal species.Tyrosine can be synthesised in the body from phenylalanine, an essential amino acid. The additive Ltyrosine is produced by acid hydrolysis of feather keratin.L-Tyrosine is considered safe for all animal species, provided that the conditions of use are respected, i.e. supplementation of conventional diets with 0.5 % L-tyrosine for food-producing animals and 1.5 % for non-food-producing species. Higher dietary concentrations may lead to growth rate depression and eye lesions, and, in young animals, behavioural changes.L-Tyrosine will be incorporated into the body protein of the animal. The protein composition will not be changed. Free L-tyrosine will not be stored in the tissues. On the basis of the data available, no risk is expected for the consumer from the use of this L-tyrosine preparation showing a purity > 95 %.In the absence of data, the product is considered potentially irritating to skin and eyes, a potential dermal sensitiser and hazardous by inhalation.The use of L-tyrosine in animal nutrition would not be expected to lead to any localised increase in the concentration of L-tyrosine or its metabolites in the environment. It is concluded that the use of this product as a fee...

show abstract

Section: Efficacymentioning

confidence: 99%

Section: Efficacymentioning

confidence: 99%

Scientific opinion on the safety and efficacy of L‐tyrosine for all animal species

2013

EFS2

View full text Add to dashboard Cite

show abstract

Feeding Sows to Maximize Reproductive and Lactation Capabilities

Libal¹

1991

Swine Nutrition

View full text Add to dashboard Cite

Isoleucine requirement of pregnant sows1

Franco

Josephson

Moehn

et al. 2013

Journal of Animal Science

View full text Add to dashboard Cite

The objective of this study was to determine the Ile requirement in early (d 39 to 61) and late (d 89 to 109) pregnancy using the indicator AA oxidation method. The same 7 Large White × Landrace sows in their fourth parity were used in early and late pregnancy. Each sow received 6 diets based on corn, corn starch, and sugar in both early and late pregnancy at constant feed allowances (2.5 kg/d). Diets provided Ile at 20, 40, 60, 80, 100, and 120% of the Ile requirement (6.2 g/d based on the 1998 NRC) in early and 60, 80, 100, 140, 160, and 180% in late pregnancy. After determination of (13)C background in expired CO2 and plasma free Phe for 1.5 h when confined in respiration chambers, sows were fed the tracer, L[1-(13)C]Phe, a rate of 2.0 mg/(kg BW·h) over 4 h divided into eight 30-min meals. Expired CO2 and plasma free Phe were analyzed for (13)C enrichment above background. Requirements were determined as the breakpoint in 2-phase nonlinear models. Sow BW was 246.5 kg in early and 271.6 kg in late pregnancy. Daily gain of the 6 sows was similar in early (344 g/d) and late pregnancy (543 g/d). During pregnancy, sow maternal gain was 19.1 ± 4.4 kg and litters of 17.7 ± 0.8 piglets weighed 22.6 ± 0.9 kg at birth. The Ile requirement was 3.6 ± 1.2 g/d (P = 0.001) in early pregnancy with a Phe retention (-0.59 g/d) and energy retention (-0.31 MJ/d) that were not different from 0. This indicates that the fourth parity sows had requirements close to maintenance in early pregnancy. The Ile requirement in late pregnancy was 9.7 ± 1.9 g/d (P = 0.001) when sows retained 3.30 g/d of Phe and -1.45 MJ/d of energy. The greater Ile requirement in late pregnancy was probably caused by the increased conceptus growth after d 70 of pregnancy. Phenylalanine flux, oxidation, and nonoxidative disposal increased (P < 0.1) from early to late pregnancy, but body protein breakdown did not. Phenylalanine oxidation, nonoxidative disposal, and retention increased (P < 0.01) with increasing Ile intake in early pregnancy but were not affected by Ile intake in late pregnancy. Body protein breakdown did not respond to Ile intake in early or late pregnancy. Although energy retention was similar in early and late pregnancy, the respiratory quotient decreased (P = 0.047) from early (1.05) to late pregnancy (0.98), indicating lipid mobilization in late pregnancy when Ile was at or above the requirement. The results of this study show that the Ile requirement of sows increases from early to late pregnancy.

show abstract

Estimation of the isoleucine and aromatic amino acid requirements of pregnant swine.

Cited by 4 publications

References 0 publications

Scientific opinion on the safety and efficacy of L‐tyrosine for all animal species

Scientific opinion on the safety and efficacy of L‐tyrosine for all animal species

Feeding Sows to Maximize Reproductive and Lactation Capabilities

Isoleucine requirement of pregnant sows1

Contact Info

Product

Resources

About