Efficiency of protein utilization in dairy cows

Hof, G.; Tamminga, S.; Lenaers, P.J.

doi:10.1016/0301-6226(94)90168-6

Cited by 26 publications

(20 citation statements)

References 15 publications

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“…Milk lactose content was significantly decreased in the Leu+/Met+ group and tended to be lower in the Leu+/Met-group at the end of the experiment compared with the initial content. In contrast, lactose yield increased at a constant lactose concentration in another study [16] when cows received more intestinally digestible protein as compared with a supply of a calculated deficiency.…”

Section: Effects Of Leucine and Methionine On Performancementioning

confidence: 95%

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

Kröber¹,

Sutter²,

Senn³

et al. 2001

Anim. Res.

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-In a 2 × 2 factorial approach the productive and metabolic response of 24 multiparous Brown Swiss cows fed rations calculated to be deficient in leucine (0.9-fold of requirements) and methionine (0.8-fold) to supplementation either of one or both of these amino acids were investigated. On a dry matter basis the rations consisted of 29% grass silage, 20% maize silage, 6% hay, and 45% concentrate. Blood plasma amino acid data confirmed the intended difference in metabolic supply of leucine and methionine keeping a low variation in the plasma levels of the other essential amino acids, particularly lysine. Live weight, milk yield as well as content and amount of milk fat were not affected by the treatments. Content and amount of milk protein were significantly reduced relative to initial level without additional methionine. Nutrient digestibility and nitrogen balance remained widely unchanged by the supplementations. Except of plasma aspartate amino transferase, cholesterol, creatinine and ornithine, which responded to methionine, hormones, enzyme activities as well as plasma, urine and milk metabolites were not systematically influenced by leucine and methionine supply. The present results gave clearer indications for a deficiency in methionine than in leucine.

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Section: Effects Of Leucine and Methionine On Performancementioning

confidence: 95%

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

Kröber¹,

Sutter²,

Senn³

et al. 2001

Anim. Res.

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“…Initially, the DVE/OEB 1991 system (CVB 1991) assumed a constant efficiency of 0•64. Later research (Hof et al 1994;Subnel et al 1994) showed that this efficiency is variable and influenced by the ratio between DVE and net energy for lactation (NE L ; MJ) as well as by the fat-and protein-corrected milk (FPCM) production level. According to Subnel et al (1994), this efficiency could adequately be described by the equation:…”

Section: Aa Composition Of Dvementioning

confidence: 99%

Update of the Dutch protein evaluation system for ruminants: the DVE/OEB₂₀₁₀system

Blok²,

et al. 2010

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SUMMARYIn the current Dutch protein evaluation system (the DVE/OEB1991system), two characteristics are calculated for each feed: true protein digested in the intestine (DVE) and the rumen degradable protein balance (OEB). Of these, DVE represents the protein value of a feed, while OEB is the difference between the potential microbial protein synthesis (MPS) on the basis of available rumen degradable protein and that on the basis of available rumen degradable energy. DVE can be separated into three components: (i) feed crude protein undegraded in the rumen but digested in the small intestine, (ii) microbial true protein synthesized in the rumen and digested in the small intestine, and (iii) endogenous protein lost in the digestive processes.Based on new research findings, the DVE/OEB1991system has recently been updated to the DVE/OEB2010system. More detail and differentiation is included concerning the representation of chemical components in feed, the rumen degradation characteristics of these components, the efficiency of MPS and the fractional passage rates. For each chemical component, the soluble, washout, potentially degradable and truly non-degradable fractions are defined with separate fractional degradation rates. Similarly, fractional passage rates for each of these fractions were identified and partly expressed as a function of fractional degradation rate. Efficiency of MPS is related to the various fractions of the chemical components and their associated fractional passage rates. Only minor changes were made with respect to the amount of DVE required for maintenance and production purposes of the animal. Differences from other current protein evaluation systems, viz. the Cornell Net Carbohydrate and Protein system and the Feed into Milk system, are discussed.

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“…Ammonia residues are converted into urea by the liver and excreted in the urine. With mobilization of muscle tissue, deamination of protein occurs (Hof et al, 1994;van Straalen, 1995). Part of the blood urea pool is excreted by urine and milk.…”

Section: Introductionmentioning

confidence: 99%

Effect of Rumen-Degradable Protein Balance and Forage Type on Bulk Milk Urea Concentration and Emission of Ammonia from Dairy Cow Houses

Duinkerken

André

Smits

et al. 2005

Journal of Dairy Science

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As the Dutch government and dairy farming sector have given priority to reducing ammonia emission, the effect of diet on the ammonia emission from dairy cow barns was studied. In addition, the usefulness of milk urea content as an indicator of emission reduction was evaluated. An experiment was carried out with a herd of 55 to 57 Holstein-Friesian dairy cows housed in a naturally ventilated barn with cubicles and a slatted floor. The experiment was designed as a 3 x 3 factorial trial and repeated 3 times. During the experiment, cows were confined to the barn (no grazing) and were fed ensiled forages and additional concentrates. The default forage was grass silage. The nutritional experimental factors were: (1) rumen-degradable protein balance of the ration for lactating cows with 3 levels (0, 500, and 1000 g/cow per d), and (2) proportion of corn silage in the forage ration for lactating cows with 3 levels (0, 50, and 100%) of forage dry matter intake. Several series of dynamic regression models were fitted. One of these models explained emission of ammonia by the nutritional factors and the temperature; another model explained ammonia emission by the bulk milk urea content and the temperature. The ammonia emission from the barn increased when levels of rumen-degradable protein balance increased. Furthermore, at a given level of rumen-degradable protein balance, the emission of ammonia correlated positively with the corn silage content in the forage ration. However, this correlation was not causal, but was the result of interaction between corn silage proportion and intake of ileal digestible protein. The bulk milk urea content and the temperature correlated strongly with the ammonia emission from the barn; the selected model accounted for 76% of the variance in emission. It was concluded that the emission of ammonia from naturally ventilated dairy cow barns was strongly influenced by diet. The emission can be reduced approximately 50% by reducing the rumen-degradable protein balance of the ration from 1000 to 0 g/cow per d. The milk urea content is a good indicator of emission reduction.

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Efficiency of protein utilization in dairy cows

Cited by 26 publications

References 15 publications

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

Update of the Dutch protein evaluation system for ruminants: the DVE/OEB₂₀₁₀system

Effect of Rumen-Degradable Protein Balance and Forage Type on Bulk Milk Urea Concentration and Emission of Ammonia from Dairy Cow Houses

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Efficiency of protein utilization in dairy cows

Cited by 26 publications

References 15 publications

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

Effects of supplying leucine and methionine to early-lactating cows fed silage-concentrate based diets with a calculated deficiency in leucine and methionine

Update of the Dutch protein evaluation system for ruminants: the DVE/OEB2010system

Effect of Rumen-Degradable Protein Balance and Forage Type on Bulk Milk Urea Concentration and Emission of Ammonia from Dairy Cow Houses

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Product

Resources

About

Update of the Dutch protein evaluation system for ruminants: the DVE/OEB₂₀₁₀system