scholarly journals The effect of high and low levels of supplementation on milk production, nitrogen utilization efficiency, and milk protein fractions in late-lactation dairy cows

2015 ◽  
Vol 98 (8) ◽  
pp. 5529-5544 ◽  
Author(s):  
M. Reid ◽  
M. O’Donovan ◽  
J.P. Murphy ◽  
C. Fleming ◽  
E. Kennedy ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Milk Protein ◽  
Nitrogen Utilization ◽  
Protein Fractions ◽  
Utilization Efficiency ◽  
Nitrogen Utilization Efficiency ◽  
Low Levels

scholarly journals Effect of Different Tannin Sources on Nutrient Intake, Digestibility, Performance, Nitrogen Utilization, and Blood Parameters in Dairy Cows

Animals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 507 ◽  
Author(s):  
Zhang ◽  
Xu ◽  
Cao ◽  
Wang ◽  
Yang ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Nutrient Intake ◽  
Control Diet ◽  
Nitrogen Retention ◽  
Blood Parameters ◽  
Nitrogen Utilization ◽  
Utilization Efficiency ◽  
Nitrogen Excretion ◽  
Nitrogen Utilization Efficiency ◽  
Dietary Treatments

This study investigated the effect of tannin sources on nutrient intake, digestibility, performance, nitrogen utilization, and blood parameters in lactating dairy cows. Four multiparous lactating Holstein cows were used in a balanced 4 × 4 Latin square design, with each period lasting 28 days. Cows were randomly assigned to one of four dietary treatments: Control diet (CON, a totally mixed ration without tannin supplements), control diet supplemented with 3% bayberry condensed tannins (BCT), control diet supplemented with 3% Acacia mangium condensed tannins (ACT), and control diet supplemented with 3% valonia hydrolyzed tannins (VHT). Dietary treatments did not significantly affect nutrient intake, milk yield or composition, microbial protein synthesis, nitrogen utilization efficiency, or plasma concentrations of glucose, non-esterified fatty acids, β-hydroxybutyrate, total protein, and globulin, or the albumin-to-globulin ratio. Tannin supplements decreased the apparent total tract nutrient digestibility to varying degrees and significantly decreased the milk and blood urea nitrogen contents (p < 0.05). Tannin supplements altered nitrogen excretion routes in lactating dairy cows, and BCT significantly decreased the urinary nitrogen excretion (p = 0.04). Compared with the CON, ACT, and VHT diets, BCT yielded the highest nitrogen retention and nitrogen retention-to-digestible nitrogen ratio despite having a similar nitrogen utilization efficiency (p < 0.05). Bayberry condensed tannin supplementation may be a potential way to improve nitrogen utilization and reduce concerns regarding nitrogen excretion in dairy cows.

Diet formulation as an effective tool for mitigating nitrogen excretion in dairy systems

2013 ◽  
Vol 4 (s1) ◽  
pp. 15-18 ◽  
Author(s):  
A. N. Hristov
Keyword(s):  
Dairy Cows ◽  
Milk Production ◽  
Dietary Protein ◽  
Milk Protein ◽  
Air Pollutant ◽  
Utilization Efficiency ◽  
Nitrogen Excretion ◽  
Ammonia Emissions ◽  
N Losses ◽  
Diet Formulation

Nitrogen (N) losses and ammonia emissions from livestock operations represent a significant water and air pollutant. It has been repeatedly demonstrated that reduction in dietary protein input results in improved N utilization efficiency and reduced N losses with manure in dairy cows. Reducing dietary protein can also benefit the producer by reducing feed cost. These interventions, however, have to be balanced with the risk of decreased productivity. If animal requirements for metabolizable protein (MP) are not met, productivity cannot be sustained. Supplementation with rumen-protected (RP) amino acids (AA) limiting milk production and milk protein synthesis may compensate for the lack of MP in dairy cow diets. Long-term experiments at Penn State University demonstrated reduced urinary N losses, blood urea, milk urea N, and ammonia emissions from manure with MP-deficient v. MP-adequate diets. In some trials, however, milk production and milk protein yield were decreased with the MP-deficient diets. Supplementation of these diets with RPAA (Lys, Met and His) increased dry matter intake and milk yield of the cows to levels comparable with MP-adequate diets and can be a successful strategy for reducing N losses and maintaining productivity in lactating dairy cows fed low-protein diets.

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