1596 Nitrogen excretion of lactating dairy cows fed an alfalfa hay– or birdsfoot trefoil hay–based high-forage diet

2016 ◽  
Vol 94 (suppl_5) ◽  
pp. 776-776
Author(s):  
M. Ghelich Khan ◽  
S. Y. Yang ◽  
J. S. Eun ◽  
J. W. MacAdam
2020 ◽  
Vol 19 (1) ◽  
pp. 1264-1274
Author(s):  
Babak Darabighane ◽  
Farzad Mirzaei Aghjehgheshlagh ◽  
Ali Mahdavi ◽  
Bahman Navidshad ◽  
John K. Bernard

1993 ◽  
Vol 76 (1) ◽  
pp. 165-174 ◽  
Author(s):  
G.A. Broderick ◽  
J.H. Yang ◽  
R.G. Koegel

1990 ◽  
Vol 73 (12) ◽  
pp. 3512-3525 ◽  
Author(s):  
D. Lubis ◽  
H.H. Van Horn ◽  
B. Harris ◽  
K.C. Bachman ◽  
S.M. Emanuele

2007 ◽  
Vol 87 (2) ◽  
pp. 237-249 ◽  
Author(s):  
J. Chiquette ◽  
G. Talbot ◽  
F. Markwell ◽  
N. Nili ◽  
R. J. Forster

Many studies have introduced exogenous bacterial strains into the rumen in an attempt to improve fermentation processes or counteract ruminal digestive disorders. Some attempts have been successful in the establishment of the new strain although others have failed. To a large extent, particular conditions necessary to the establishment of a new strain are not yet fully understood. In the present study, Ruminococcus flavefaciens NJ (NJ), isolated from the rumen of a wild moose, was introduced into the rumen of six ruminally fistulated non-lactating dairy cows receiving either a high concentrate or a high forage diet and supplemented on a daily basis with a probiotic mixture. In a second experiment, NJ and the probiotic mixture were given to young calves of 21 to 35 d of age. During repeated dosing, NJ modified the abundance of other cellulolytic bacterial populations compared with periods with no dosing. NJ also improved in sacco digestibility of timothy hay with the high concentrate diet. NJ declined rapidly in the rumen from 106 cells mL-1 after dosing to 102 cells mL-1, 24 h following dosing. The persistence of NJ increased with weeks of dosing in cows or when introduced in the rumen of young calves (105 cells mL-1 after 48 h and 102 cells mL-1 after 7 d). The presence of probiotics or a change in the concentrate to forage ratio in the diet did not succeed in establishing the new strain in the rumen. Key words: Ruminococcus flavefaciens NJ, probiotics, rumen fermentation, cellulolytic populations, in sacco digestibility, non-lactating dairy cows


2018 ◽  
Vol 61 (5) ◽  
pp. 1713-1727
Author(s):  
Ruilan Dong ◽  
Hongmin Dong ◽  
Karen A. Beauchemin ◽  
Hongwei Xin

Abstract. Manure nitrogen (N) output from dairy cattle is a major environmental concern in China. Various empirical models are available to predict manure N output from dairy cattle, but the accuracy and precision of these models has not been assessed for Chinese conditions. The objective of this study was to evaluate the performance of extant models that predict different forms of manure N output for lactating dairy cows in China with the aim of identifying the best-fit and most suitable prediction models. A total of 35 empirical models were evaluated for their ability to predict N excretion of dairy cows in China fed a wide range of diets. The data set consisted of 99 treatment means from 32 publications with information on animal and dietary characteristics and N output flows. Performance of the models was evaluated using root mean square prediction error (RMSPE) and concordance correlation coefficient (CCC) analysis. A model (eq. 19) based on N intake (NI) was selected as best for predicting fecal N excretion (RMSPE = 15.8% and CCC = 0.75). Another model that also used NI as an input variable was most suitable for predicting urinary N (RMSPE = 26.0% and CCC = 0.63, eq. 14) and total N (RMSPE = 15.8% and CCC = 0.81, eq. 31). Models predicting urinary urea N (UUN) and urinary N / total N performed poorly. Overall, the deviation of the regression line from the equality line (y = x line) for even the best-fit urinary, fecal, and total N excretion models demonstrated the need to develop improved models for use under Chinese conditions. Using N output data from dairy cows in China to develop manure N output models may help improve environmental stewardship of the dairy industry in China. Keywords: Dairy cows, Evaluation, Manures, Model performance, Nitrogen excretion.


1968 ◽  
Vol 51 (10) ◽  
pp. 1620-1624 ◽  
Author(s):  
D.A. Stiles ◽  
E.E. Bartley ◽  
G.L. Kilgore ◽  
F.W. Boren ◽  
R.L. Ott ◽  
...  

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