Sulphur Metabolism and Excretion Studies in Ruminants VIII. Methionine Degradation and Utilization in Sheep When Infused Into the Rumen or Abomasum

Abstract

Methionine (2 g/day) was continuously infused either abomasally or ruminally into two groups of sheep (four per group) over a 6-week period. After a further 6 weeks on the basal diet, which supplied daily 900 g dry matter, 18· 3 g nitrogen, and 1· 45 g sulphur, the infusion treatments were reversed. A control group of four sheep did not receive infusions. After 13 days on each treatment L-[35S}methionine was continuously infused, along with the carrier methionine, for 5 days during which the sheep were fed at 2-hourly intervals.Of the [35S]methionine infused ruminally 74% of the 35S flowed to the omasum; 6'4% of this was inorganic 35S. A large proportion of the organic 35S was associated with microbial or particulate ma,terial. It was estimated that less than a quarter of the 35S could have been as free methionine. Partial degradation of methionine may account for portion of the organic 35S found in omasal digesta. Wool growth and sulphur content of the wool was increased by 28 v. 68% and 4'5% v. 19'7% above the controls for ruminal or abomasal infusions, respectively. Body weight gains also improved with methionine infusions: control, ruminal, and abomasal treatment mean gains were 0·09, 0,41, and 0·66 kg/week, respectively. Larger nitrogen and sulphur balances were associated with the greater responses to abomasal infusions. Ruminal infusions did not alter the flow of protein to the omasum or the digestibility of organic matter.The responses obtained with ruminal infusions of methionine suggest that increasing the dietary intake of methionine, or the rate of fluid flow from the rumen, may ena,ble dietary supplements of methionine to effect improvements in wool production and body weight gains.

Thiols in wetland interstitial waters and their role in mercury and methylmercury speciation

“…Microbial pathways for the formation of cysteine, glutathione, and 3-MPA have been well documented in laboratory cultures and in marine sediments (Bird and Moir 1972;Salsbury and Merricks 1975;Kiene and Taylor 1988). Thiols in surface coastal wa- ters have also been attributed to marine phytoplankton (AlFarawati and Van Den Berg 2001;Matrai and Vetter 1988).…”

“…Nanomolar to millimolar levels of thiols have been commonly reported in seawater (Matrai and Vetter 1988;Tang et al 2000a;Al-Farawati and van den Berg 2001) and marine sediment interstitial waters (Luther et al 1986; Kiene and Taylor 1988;MacCrehan and Shea 1995). They can be formed via a variety of pathways, including (1) microbial deamination of sulfur-containing amino acids (Bird and Moir 1972;Salsbury and Merricks 1975;Mopper and Taylor 1986), (2) microbial degradation of dimethylsulfoniopropionate (DMSP) (Shea and MacCrehan 1988) produced by marine algae and halophytic plants (Yoch 2002), and (3) abiotic Michael addition reaction between sulfide or polysulfides and unsaturated organic compounds (Mopper and Taylor 1986;Mopper 1987, 1989). Although their biogeochemical significance in the early diagenesis of organic matter, sulfur (Aizenshtat et al 1995;Boulegue et al 1982), and trace metals such as Cu (Shea and MacCrehan 1988;Leal and Van Den Berg 1998) has been increasingly documented in marine sediments, little is known about the nature, distribution, and biogeochemical roles of thiols in freshwater systems.…”

Promotion of cashmere growth by sulfur supplements in cashmere goats

“…Wool growth requires high levels of SAA (Reis, 1989). Bird & Moir (1972) found that methionine infusion through the rumen or abomasums raised the wool yield. The study by Souri et al (1996) demonstrated that methionine is essential to support the growth and the viability of secondary follicles of the cashmere goats in vitro.…”

Sulfur and Methionine Metabolism in Sheep. IV. Metabolism and Absorption in the Intestines

“…Of the total sulfur reaching the omasum, c. 40 % was apparently digested in the remainder of the tract (Bird and Moir 1972). But, when bacteria labelled with 35S were injected into the abomasum or caecum the apparent digestibilities of the microbial sulfur were 71 % (Bird 1972a) and 31% (Judson et al 1975) respectively.…”