Effect of Protein Level during Pregnancy and Lactation on Plasma Amino Acid Profile of Swine

Leucine and valine requirements of the lactating sow

“…The relationship between composition of dietary protein and changes in plasma amino acid patterns has been extensively studied (Puchal et al, 1962;Lucas et al, 1969;Nordstrom et al, 1970;Davey et al, 1973;Itch et al, 1974). Robinson et al (1974) using 34 kg pigs established corre lation coefficients relating plasma amino acids levels to dietar citent for isoleucine, leucine and valine of 0.99, 0.88 and 0.92, respectively.…”

The sulfur-amino acid requirement for reproducing gilts

“…This is a common observation of gestation performance and has been reported by numerous researchers. Lucas e^ al. (1969) showed that the sulfur-amino acids were the first limiting amino acids in this basal diet.…”

“…Earlier work at Iowa State University (Holden et , 1968) indi cated that a balanced eight percent crude protein diet would support satisfactory reproductive performance over a long term experiment (four parities). Lucas ^ (1969) measured the amino acid composition of this diet and the levels of plasma-free amino acids of the sows consuming the diets at the 100th day of gestation and observed that methionine and cystine were the first-limiting amino acids in the eight percent protein diet. Since this basal diet was considered adequate for reproductive per formance, with methionine and cystine considered to be the first limiting, an experiment was designed using this diet to estimate the dietary re quirement for methionine and cystine.…”

“…This response is similar to that observed in experiment 6808 and again probably reflects the metabolic demands on available non essential amino nitrogen, including its conversion to proline and hydroxyproline.Compared to the plasma levels reported byLucas e_t a^, (1969) our observed level of plasma methionine is similar and cysLine about two to three times greater than they observed on the eight percent protein diet.Plasma histidine, threonine and valine are 20 to 40 percent less. The mature sows used byLucas (1969) could be expected to require relatively more cystine than gilts because a-larger share of their dietary intake is used for replacement of hair and skin rather than for growth.Amino acid ratios were determined by dividing the fed level of each plasma amino acid by the fasted level sampled one hour previous to the collection of the fed sample. The means, expressed as percentages, and analyses of variance are shown inTables 17 and 18.…”

Isoleucine and leucine requirements of the lactating sow

“…In 1964, Allison and others, using rats, established a correlation between cellular protein content of muscle tissue and the ability of the animal to survive stresses of amino acid or protein deprivation. They stated that it was possible that muscle is a major source of protein reserve in the body and some of these tissue (Puchal et al, 1962;Swendseld et al, 1963;Lucas et al, 1969;Nordstrom, et al, 1970;Davey et al, 1973;Itoh et al, 1974). Leung et al (1968), Clark et al (1973) andNoda (1975) ail indicated that the plasma amino acid pattern of animals fed an amino acid-deficient diet is characterized by a very low concentration of the amino acid that limits growth.…”