Dietary lysine and threonine utilization by young pigs: Efficiency for carcass growth

Abstract

Iletary tyslne retention, a basal diet was formulated to contain 6 g of lysine kg-1. Twelve pigs were fed the basal diet supplemented with LJysine.HCl to contain 6, 7 , or 8 g of lysine kg-1. Daily weight gain and gain:feed ratio were higher (P < 0.05) for pigs fed 8 g of lysine than for pigs fed 6 g of lysine kg-l diet. The accretion rates of dry rnatter, protein, ash, and lysine in the carcass were trigtrer ior pigs fed S g of tysinJttran for pigs fed 6 g of lysine kg-l diet. A linear regression of daily carcass lysine accretion on aaily lysine intake resulted inaT2Va effi-iency of carcass lysine accretion above maintenance. In the second experiment, three dieti including a basal diet formulated to contain 4 g of threonine kg-1 and supplemented with L-threonine to contain 4, 4.65' or 5.3 g of threonine kg-1 were fed to 12 pigs. Rate and efficiency of body weight gain exhibited a dose-response improvement (P < 0.05) to an increase in dietary threonini.-C*.urr protein, ash, and threonine accretion rates were higher (P < 0.05) for pigs fed 5.3 g of threonine than those fed 4 g of threonine kg-1 diet. Linear regression of daily carcass threonine accretion on daily threonine intake resulted in extra-maintenance efficiency of threonine retention of 6OVo. The efficiencies of dietary lysine and threonine utilization for carcass growth in pigs within the liveweight range of 10-20 kg are 72 and 6OVo, respectively'

Efficiency of methionine retention in ducks

“…The observation that the methionine, cysteine, arginine and threonine concentrations of body protein increased in response to supplemental dietary methionine concentration is in agreement with previous work in which there were increases in the concentration of a variety of amino acids in body protein from pigs and broiler chickens with increasing concentrations of dietary amino acids (Heger & Frydrych, 1985;Chung & Baker, 1992;Bikker et al 1994;Adeola, 1995Adeola, , 1998Edwards et al 1997). Furthermore, the amino acid intake-related changes in body amino acid concentration noted in the current study are consistent with the expected increase in proportion of contractile proteins relative to collagen protein.…”

“…The role of coprophagy in the observations by Heger & Frydrych (1985) and Gahl et al (1991) cannot be quantified and may be responsible for the observations, as Baker et al (1996) suggested. The current data, as well as the lysine retention data of Batterham et al (1990), Adeola (1995) and Heger et al (2002) with pigs, the lysine, isoleucine and valine retention data of Baker (1991) and Baker et al (1996) with chicks, and the data on branched-chain and large-neutral amino acids from Heger et al (2003) with pigs, lend support to the notion that, within a range of limiting amino acid intake that is close to optimal, the above-maintenance efficiency of retention of an individual amino acid is constant. Linear regression relating methionine accretion to intake indicated that the efficiency of methionine retention in ducks was 31 %.…”

“…Adeola (1995) reported that lysine was retained more efficiently than threonine in pigs. Edwards et al (1997, and , reported that the efficiency of dietary threonine, lysine and methionine retention in young chicks was 82 %, 79 % and 68 %, respectively.…”

“…The amount of dietary protein that must be supplied is dependent on the efficiency with which dietary protein is used for body functions. However, the efficiency of dietary protein utilisation is not necessarily equal to that of individual amino acids (Baker, 1991;Chung & Baker, 1992).Thus, data on dietary protein utilisation provide no knowledge on the efficiency of utilisation of individual amino acids, and there is evidence in pigs, chickens and rats that these efficiencies are not equal between amino acids within species (Gahl et al 1991;Batterham et al 1990;Bikker et al 1994;Adeola, 1995;Baker et al 1996;Sklan & Noy, 2004). Adeola (1995) reported that lysine was retained more efficiently than threonine in pigs.…”

Comparative nutrition and metabolism: Explication of open questions with emphasis on protein and amino acids

“…Because the gastrointestinal tract of pigs is similar to that of humans, microbial synthesis and subsequent absorption of amino acids probably also contribute importantly to the maintenance amino acid requirement of humans (55,56). (54,(57)(58)(59)(60)(61)(62). Thus, at well below required levels, amino acids recovered in whole-body protein represent only 50-90% of the amino acids fed (i.e., absorbed, because the amino acids fed are crystalline amino acids or derived from highly digestible casein).…”