Supplementation of Diets with Positive and Negative Urea Fermentation Potential Using Urea or Soybean Meal

Poos, Mary I.; Bull, L. S.; Hemken, R.W.

doi:10.2527/jas1979.4951417x

Cited by 38 publications

(18 citation statements)

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“…As the results indicated, both conditions were met. Urea toxicity was not a concern because of the amount of readily fermentable carbohydrates in the basal diet (41.6% NFC; Table 2) and because inclusion rates of 1 to 2% urea in diet DM have been used in high-grain diets without adverse effects (Poos et al, 1979). Indeed, no signs of urea toxicity were observed in any of the animals in the study.…”

Section: Dietary Treatmentsmentioning

confidence: 88%

Effect of Incremental Urea Supplementation of a Conventional Corn Silage-Based Diet on Ruminal Ammonia Concentration and Synthesis of Microbial Protein

Boucher

Ordway²,

Whitehouse

et al. 2007

Journal of Dairy Science

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One primiparous and 3 multiparous lactating Holstein cows fitted with ruminal and duodenal cannulas were used in a 4 × 4 Latin square design to determine the efficacy of adding urea to a corn silage-based diet on ruminal fermentation and microbial protein synthesis. Dietary treatments were 0, 0.3, 0.6, and 0.9% urea in diet dry matter (DM); urea was manually top dressed and incorporated into the ration. The basal diet contained (DM basis) 52% forage (with 61% of forage provided as corn silage) and 48% concentrate ingredients. The basal diet was formulated to meet National Research Council (NRC, 2001) requirements for energy and all nutrients except rumen-degradable protein (RDP) and metabolizable protein. Experimental periods lasted 14 d with the first 9 d for adaptation. The basal diet, without urea addition, contained 9.2% RDP in DM and had a predicted RDP balance of −167 g/d (NRC, 2001). There were no effects of dietary treatment on ruminal true digestibility of organic matter or ruminal apparent digestibility of neutral detergent fiber and acid detergent fiber. Total ruminal volatile fatty acid concentrations increased linearly with increasing urea level. Feeding increasing amounts of urea quadratically increased rumen ammonia N concentrations (9.0, 11.9, 12.8, and 17.4 mg/dL at 0, 0.3, 0.6, and 0.9% urea supplementation, respectively), passage of microbial N, and microbial N in duodenal digesta as a percentage of nonammonia N. The results of this study indicate that there were some positive effects of adding urea to the described lactating dairy cow diet, and that microbial protein synthesis was maximized at an average Received January 8, 2007. Accepted August 10, 2007 This is Scientific Contribution Number 2321 from the New Hampshire Agricultural Experiment Station. 2Corresponding author: charles.schwab@unh.edu 5619 ruminal ammonia N concentration of 12.8 mg/dL when urea was added at 0.6% in diet DM.

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Section: Dietary Treatmentsmentioning

confidence: 88%

Effect of Incremental Urea Supplementation of a Conventional Corn Silage-Based Diet on Ruminal Ammonia Concentration and Synthesis of Microbial Protein

Boucher

Ordway²,

Whitehouse

et al. 2007

Journal of Dairy Science

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“…This implies that at least part of the response could be related to overcoming the limited supply of rumen-degradable nitrogen for rumen microbes. Soybean meal has some-times increased diet digestibility more than isonitrogenous urea supplementation (Poos et al, 1979;Smith et al, 1980), suggesting that the form of nitrogen also may influence ruminal fiber digestion.…”

Section: Effects Of Protein Supplementationmentioning

confidence: 99%

A meta-analysis of feed digestion in dairy cows. 1. The effects of forage and concentrate factors on total diet digestibility

Nousiainen

Rinne

Huhtanen

2009

Journal of Dairy Science

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A meta-analysis based on published experiments with lactating dairy cows was conducted to study the effects of dietary forage and concentrate factors on apparent total diet digestibility. A data set was collected that included a total of 497 dietary treatment means from 92 studies. The diets were based on grass silage or on legume or whole-crop cereal silages partly or completely substituted for grass silage. The silages were supplemented with concentrates given at a flat rate within a dietary comparison. For the statistical evaluation, the data were divided into 5 subsets to quantify silage (digestibility, 42 diets in 17 studies; fermentation characteristics, 108 diets in 39 studies) and concentrate (amount of supplementation, 142 diets in 59 studies; concentration of crude protein, 215 diets in 82 studies; carbohydrate composition, 66 diets in 23 studies) factors on total diet digestibility. The diet digestibility of dairy cows was determined by total fecal collection or by using acid-insoluble ash as an internal marker. Diet organic matter digestibility (OMD) at a maintenance level of feeding (OMD(m)) was estimated using sheep in vivo or corresponding in vitro digestibility values for the forage and reported ingredient and chemical composition values, with tabulated digestibility coefficients for the concentrate components of the diet. A mixed model regression analysis was used to detect the responses of different dietary factors on apparent total diet digestibility. Improved silage OMD(m) resulting from earlier harvest was translated into improved production-level OMD in cows (OMD(p)). The effects of silage fermentation characteristics on OMD(p) were quantitatively small, although sometimes significant. Concentrate supplementation improved total diet OMD(m), but this was not realized in lactating dairy cows because of linearly decreased neutral detergent fiber (NDF) digestibility as concentrate intake increased. Increasing the concentrate crude protein amount quadratically improved OMD(p) in cows, with the response being mostly due to improved NDF digestibility. Replacement of starchy concentrates with fibrous by-products slightly decreased OMD(p) but tended to improve NDF digestibility. The true digestibility of cell solubles (OM - NDF) estimated by the Lucas test both from all data and from the data subsets was not significantly different from 1.00, suggesting that responses in OMD(p) of dairy cows are mediated through changes in the concentration and digestibility of NDF.

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“…In this trial neither of the two moderate CP diets (+UDP or +RDP) resulted in an increase in milk production above that of the control diet. An increase in supply of rumen-degradable N (RDN) presumably increases digestibility and thus encourages higher food intakes as demonstrated by Poos, Bull and Hemken (1979). An increase in supply of rumen-degradable N (RDN) presumably increases digestibility and thus encourages higher food intakes as demonstrated by Poos, Bull and Hemken (1979).…”

Section: Crude Protein Levelmentioning

confidence: 99%

The influence of a formulated excess of rumen degradable protein or undegradable protein on milk production in dairy cows in early lactation

Sloan¹,

Rowlinson²,

Armstrong³

1988

Anim. Sci.

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Following a 3-week covariance period, 30 group-housed dairy cows were individually given one of three diets from week 4 to week 13 of lactation to determine any possible advantage in milk yield and production of feeding levels of undegradable protein (+UDP) or rumen-degradable protein (+RDP) above the minimum levels (control) proposed by the Agricultural Research Council (ARC, 1984). The three concentrates given were formulated to be of equivalent metabolizable energy (ME, 13-5 MJ/kg dry matter (DM)) concentration and each consisted of rolled barley plus a protein supplement: control (crude protein (CP), 129 g/kg DM) 0-35 kg DM fish meal per day; +UDP (CP, 167 g7kg DM) 1-0 kg DM fish meal per day; and +RDP (CP, 167 g/kg DM) 1-5 kg DM soya per day. For each group the total 'concentrate' allowance per animal per day was 11-6 kg fresh weight and was given in three equal feeds. Grass silage (CP 122 g/kg DM, ME 10-6 MJ/kg DM) was given ad libitum. For the control, +UDP and +RDP treatments, respectively, mean grass silage intakes were 8-29, 8-62 and 8-65 kg/day and mean milk yields were 26-6, 26-3 and 26-1 kg/day. These were not significantly different (P > 0-05). Milk fat concentration was lower (P < 005) for the +UDP treatment (36-4 g/kg) in comparison with the control (38-6 g/kg) or the +RDP treatment (39-7 g/kg) but no other milk constituent was significantly influenced by treatment. There was a trend for a greater live-weight gain with treatment +UDP (0-81 kg/day) compared with the other two treatments (control 0-50, +RDP 0-51 kg/day) but there were no differences in condition-score change between treatments. In this trial there was no advantage to feeding formulated levels of UDP or RDP above those proposed by ARC (1984).

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Supplementation of Diets with Positive and Negative Urea Fermentation Potential Using Urea or Soybean Meal

Cited by 38 publications

References 0 publications

Effect of Incremental Urea Supplementation of a Conventional Corn Silage-Based Diet on Ruminal Ammonia Concentration and Synthesis of Microbial Protein

Effect of Incremental Urea Supplementation of a Conventional Corn Silage-Based Diet on Ruminal Ammonia Concentration and Synthesis of Microbial Protein

A meta-analysis of feed digestion in dairy cows. 1. The effects of forage and concentrate factors on total diet digestibility

The influence of a formulated excess of rumen degradable protein or undegradable protein on milk production in dairy cows in early lactation

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