Effects of energy balance and metabolizable protein level on tissue mobilization and milk performance of dairy cows in early lactation

Schei, I.; Volden, H.; Baevre, L.

doi:10.1016/j.livprodsci.2004.11.039

Cited by 28 publications

(33 citation statements)

References 37 publications

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“…Choosing an AA profile other than casein that is more realistic to a practical feeding situation is important (Chamberlain and Yeo, 2003). DePeters and Cant (1992) and Schei et al (2005) suggested that milk responses to additional nutrient supply depend on animal energy and nutrient balances. The production experiment of Schei et al (2005) showed that increased metabolisable protein supply, when cows were in negative energy balance, increased milk protein production.…”

Section: Discussionmentioning

confidence: 99%

“…DePeters and Cant (1992) and Schei et al (2005) suggested that milk responses to additional nutrient supply depend on animal energy and nutrient balances. The production experiment of Schei et al (2005) showed that increased metabolisable protein supply, when cows were in negative energy balance, increased milk protein production. However, it was not clear if the positive response was explained by solely an increased AA supply or a combination with increased glucose supply from increased gluconeogenesis.…”

Section: Discussionmentioning

confidence: 99%

“…Compared with the dietary metabolisable protein intake (the basal diet), abomasal infusion of 400 g AA increased the metabolisable AA supply by more than 20%, which has been shown to increase daily milk yield by 2.8 kg and milk protein production by 104 g in early lactating cows on low energy supply (Schei et al, 2005). Volden (1999) observed a 1.8-kg increase in milk yield with 190 g increased duodenal AA supply in early lactating cows.…”

Section: Discussionmentioning

confidence: 99%

“…Production and infusion experiments that have evaluated these factors have shown variable success in affecting both milk protein production and content. The low and variable response of metabolisable protein supply on milk protein production (Aikman et al, 2002;Raggio et al, 2004;Schei et al, 2005) may be due to the fact that some AA are utilised as an energy source, some AA are used as a glucogenic precursors and also, increased AA supplementation may affect hormones regulating lactogenic metabolism (Reynolds et al, 1994). Further improvement in prediction of dietary effects on milk protein production requires a better understanding of factors affecting intermediary metabolism of glucogenic substrates and AA.…”

Section: Introductionmentioning

confidence: 99%

“…Cows in negative energy balance have a high need for glucose because they mobilise fat as energy and have limited body reserves of glucogenic compounds. A combination of low energy supply and high metabolisable protein supply has shown to stimulate milk production (Ørskov et al, 1981;Schei et al, 2005). However, it is not clear if this response is solely explained by increased AA supply or that part of the AA has been used as source for glucose and thus improved glucogenic status of the animal.…”

Section: Introductionmentioning

confidence: 99%

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Post-ruminal or intravenous infusions of carbohydrates or amino acids to dairy cows 1. Early lactation

Schei

Danfær²,

Boman

et al. 2007

Animal

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The objectives of this study were to compare the effects of post-ruminal and intravenous infusions of wheat starch or glucose (CHO) or a mixture of amino acids (AA) on milk protein yield, nitrogen utilisation, plasma metabolites and mammary extraction rate of dairy cows in early lactation. Eight cow, ruminally fistulated, was assigned to two 4 £ 4 Latin squares during 14-day periods, where the last 7 days were for infusions. Infusions were: (1) starch in the abomasum (SP), (2) glucose in the blood (GB), (3) AA in the abomasum (AP), and (4) AA in the blood (AB). The experiment started 54^4 days (mean^S.E.) post partum (milk yield 33.4^1.7 kg). Daily amounts of nutrients infused were 378, 365, 341, and 333 g for SP, GB, AP and AB, respectively. The cows were fed a basal diet consisting of a concentrate mixture and grass silage (55:45 on dry-matter (DM) basis), and DM intake was 17.2 kg/day. Milk production was affected by site of infusion within substrate, whereas infusion substrates within infusion site (CHO or AA) were of minor importance. Compared with SP infusion, GB infusion increased ( P , 0.05) milk protein yield and concentration by 55 g and 1 g/kg. The AB infusion tended to ( P , 0.10) increase milk yield and ECM and increased ( P , 0.05) protein yield and concentration by 1.8 and 2.2 kg, 83 g and 1.1 g/kg compared with AP infusion, respectively. Nitrogen balance data indicated higher losses of metabolic faecal nitrogen (MFN) by abomasal than by intravenous infusions, and an increased ( P , 0.05) catabolism for AP and AB infusions compared with SP and GB infusions. GB infusion did not increase ( P . 0.10) plasma glucose or insulin concentrations above that of SP infusion. Compared with the SP infusion, the GB infusion had minor effect on plasma AA. AP infusion increased ( P , 0.05) plasma non-essential AA (NEAA) concentration compared with AB infusion, whereas infusion site of AA had no effect ( P . 0.05) on essential AA (EAA) or branched-chain AA (BCAA). Although a higher milk protein synthesis was observed for AB infusion, the mammary extraction rate was not higher ( P . 0.05) than for AP infusion. Across infusion site, AP and AB infusions increased plasma concentration of EAA and BCAA, but compared with GB infusion, the mammary extraction rates tended ( P , 0.10) to be lower. It is concluded that abomasal nutrient infusion increases loss of MFN and that the gastrointestinal metabolism influences the nutrients available for milk synthesis. Our conclusion is that when glucose was infused, AA limited a further milk protein synthesis, but when AA was infused, glucose or energy substrate might have been the limiting factor. Our results verify that glucogenic substrates are limiting when cows are in negative energy balance.

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