Effects of the ratio of effective rumen degradable protein to fermentable metabolizable energy on voluntary intake and milk yields of dairy cows

2001 ◽  
Vol 2001 ◽  
pp. 184-184
Author(s):  
A.R.J. Cabrita ◽  
A.J.M. Fonseca ◽  
C. Sampaio ◽  
E. Gomes ◽  
R.J. Dewhurst
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Metabolizable Energy ◽  
Microbial Protein ◽  
Maize Silage ◽  
Protein Sources ◽  
Microbial Protein Synthesis ◽  
Voluntary Intake ◽  
Production Response ◽  
Degradable Protein

Diets with low ratios of effective rumen degradable protein (ERDP) to fermentable metabolizable energy (FME) are often offered to dairy cows in Portugal, because they are based on maize silage and protein sources are very expensive. It seems likely that this will restrict microbial protein synthesis and voluntary intake and, consequently, lead to reduced milk yields. The objective of this study was to examine the production response of dairy cows offered diets differing in ERDP/FME ratio.

Effect of the different ratios of effective rumen degradable protein to fermentable metabolizable energy on early lactating Holstein cow performances

2005 ◽  
Vol 2005 ◽  
pp. 189-189
Author(s):  
F. Rezaii ◽  
M. Danesh Mesgaran ◽  
A. R. Heravi Moosavi
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Metabolizable Energy ◽  
Nitrogen Excretion ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
N Utilization ◽  
Metabolisable Energy ◽  
The Cost ◽  
Degradable Protein

The efficiency of dietary N by dairy cows is generally low, and in part, may be related to an impaired utilization of N in the rumen. A major determinant of microbial protein synthesis is the availability of energy-yielding substrates (Castillo et al., 2001). It seems likely that low ratios of effective rumen degradable protein (ERDP) to fermentable metabolisable energy (FME) will restrict microbial protein synthesis and dry matter intake and, consequently, lead to reduced milk yield (Cabrita et al., 2003). Nitrogen excretion in faeces and urine accounts for a high proportion of N intake, which may be more than 70% of the daily N consumption. Environmental pollution from N as ammonia and nitrates is regarded as a major potential problem world wide. Nutritional manipulations might be a way of significantly increasing N utilization and decreasing N pollution by dairy cows, and where as protein sources are expensive so, the cost of diet decrease (Castillo et al., 2001). The objective of this study was to examine the product and component of milk of dairy cows offered diets with different ratios of ERDP/FME.

Limitations in digestible methionine in the intestine (MetDI) for milk protein secretion in dairy cows fed a ration based on grass silage

1995 ◽  
Vol 1995 ◽  
pp. 158-158
Author(s):  
Y. Chilliard ◽  
J. Rouel ◽  
A. Ollier ◽  
J. Bony ◽  
K. Tanan ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Small Intestine ◽  
Dairy Cows ◽  
Protein Secretion ◽  
Milk Protein ◽  
Microbial Protein ◽  
Maize Silage ◽  
Microbial Protein Synthesis ◽  
Grass Silage

The interest for increasing post-ruminal methionine supplies for dairy cows fed maize silage based rations has been clearly demonstrated (Sloan 1992). Theoretically grass silage based rations are also deficient in methionine in most dietary situations. Expressed as a percentage of PDIE (protein digestible in the small intestine when energy is limiting microbial protein synthesis in the rumen) the metDI value for grass silage approximates 1.95 compared to 1.97 for maize silage.This trial was conducted, to verify, if in practice, methionine alone could limit milk protein secretion in dairy cows fed grass silage based rations.

Effect of synchronizing the rate of dietary energy and nitrogen release on rumen fermentation and microbial protein synthesis in sheep

1993 ◽  
Vol 120 (2) ◽  
pp. 251-263 ◽  
Author(s):  
L. A. Sinclair ◽  
P. C. Garnsworth ◽  
J. R. Newbold ◽  
P. J. Buttery
Keyword(s):  
Protein Synthesis ◽  
Volatile Fatty Acids ◽  
Rumen Fermentation ◽  
Metabolizable Energy ◽  
Raw Material ◽  
Microbial Protein ◽  
Barley Malt ◽  
Mean Values ◽  
Microbial Protein Synthesis ◽  
Degradable Protein

SUMMARYThe effects of two diets formulated to be either synchronous or asynchronous with respect to the hourly supply of energy and nitrogen on rumen fermentation and microbial protein synthesis were studied in sheep.In Expt 1, the in situ degradation characteristics of nitrogen (N), organic matter (OM) and carbohydrate (CHO) fractions were determined in winter wheat straw, winter barley, malt distillers dark grains rapeseed meal and fishmeal. The feeds exhibited a large range in degradability characteristics of the nitrogen and energy-yielding fractions.A computer program was developed based upon the raw material degradation characteristics obtained from the above studies. The program was used to formulate two diets with similar metabolizable energy (9·5 MJ/kg DM) and rumen degradable protein contents (96 g/kg DM) but to be either synchronous (diet A) or asynchronous (diet B) with respect to the hourly rate of release of N and energy. The program was used to predict the hourly release of N, OM and CHO and the molar production of volatile fatty acids (VFA).In Expt 2, the two diets were fed to four cannulated sheep at the rate of 1 kg/day in four equal portions, in two periods, using a change-over design. Rumen ammonia concentrations followed the predicted rate of N degradation. A maximum concentration of 10·5 and 7 mM for diets A and B respectively was achieved within the first hour of feeding which then fell to 7 and 3 mM respectively. Rumen VFA proportions were more stable for the synchronous diet (A) than the asynchronous diet (B) and were more stable than predicted for both diets. True ruminal degradation of OM and CHO was similar for both diets and close to that predicted, although fibre degradability in diet A was 30% lower than predicted due to a reduction in both cellulose and hemicellulose digested. Microbial protein production was estimated simultaneously with L-[4,5–3H]leucine and a technique based on cytosine. Estimates varied with marker but mean values indicated a 27% greater production of microbial N (g N/kg DM I) with the synchronous diet (A) and an average improvement in microbial protein efficiency (g N/kg OM truly degraded or CHO apparently degraded) of 13%, although neither difference was significant. There was evidence of a greater recycling of N in the animals and a significantly lower content of rumen degradable protein when the sheep were fed the asynchronous diet (B).The results are consistent with the view that synchronizing the rate of supply of N and energyyielding substrates to the rumen micro-organisms based upon ingredient in situ degradation data can improve microbial protein flow at the duodenum and the efficiency of microbial protein synthesis.

scholarly journals The efficiency of microbial protein synthesis in the rumen and the degradability of feed nitrogen between the mouth and abomasum in steers given different diets

1984 ◽  
Vol 51 (1) ◽  
pp. 77-83 ◽  
Author(s):  
A. B. McAllan ◽  
R. H. Smith
Keyword(s):  
Protein Synthesis ◽  
Fish Meal ◽  
Basal Diet ◽  
Metabolizable Energy ◽  
Diaminopimelic Acid ◽  
Barley Straw ◽  
Microbial Protein ◽  
Total N ◽  
Microbial Protein Synthesis ◽  
Mixed Bacteria

1. Protozoa-free steers with simple rumen and abomasal cannulas were given basal diets consisting of a concentrate mixture of flaked maize and tapioca with barley straw (BS) or alkali-treated barley straw (BSA). Other diets were supplemented with urea (BSU and BSAU respectively) or with fish meal replacing the tapioca (BSF and BSAF respectively). The diets were isoenergetic and calculated to provide sufficient metabolizable energy (ME) to support a growth rate of 0.5 kg/d. Rumen-degradable nitrogen (RDN): ME values (g/MJ) were estimated to be 0.50, 1.20 and 0.80 for the basal diet, urea- and fish-meal-supplemented diets respectively. RNA and α, ε-diaminopimelic acid (DAP) were used as microbial markers. 103Ruthenium and polyethylene glycol (PEG) were given as flow markers and flows (g/24 h) at the abomasum of organic matter (OM) and nitrogenous constituents were calculated.2. Samples of mixed bacteria separated from rumen digesta from animals receiving N-supplemented diets contained significantly more N than those from animals receiving basal diets (approximately 74 and 62 mg/g dry matter (DM) respectively) but there were no other significant differences in total-N contents between treatments. RNA-N: total-N values were similar for all diets (approximately 0.13). DAP-N: total-N values were significantly lower in bacteria from animals receiving alkali-treated (AT) rather than untreated (UT) straw (approximately 0.008 and 0.011 respectively).3. The proportion of OM intake digested in the rumen (ADOM) was significantly higher for animals receiving AT straw rather than UT straw (approximately 0.54 and 0.43 respectively). N supplementation had no effect on OM digestibility.4. When basal rather than N-supplemented diets or AT-straw- rather than UT-straw-containing diets were given, there were significantly lower flows of ammonia-N, non-ammonia-N (NAN) and microbial-N (based on RNA flow, MN(RNA)) at the abomasum. Mean daily MN(RNA) flows (g) were 21, 30, 31, 16, 27 and 28 for diets BS, BSU, BSF, BSA, BSAU and BSAF respectively. These correspond to estimated efficiencies of microbial protein synthesis, expressed as g MN(RNA) /kg truly-digested OM, at 14, 22, 22, 12, 18 and 19 respectively. Values were significantly lower for basal as compared with corresponding N-supplemented diets and for AT-straw diets as compared with corresponding UT-straw diets.5. Estimated mean proportions of total feed-N intake degraded in the rumen, based on MN(RNA) as microbial marker, of diets BS, BSU and BSF were 0.60, 0.74 and 0.47 respectively; corresponding values for diets BSA, BSAU and BSAF were 0.72, 0.73 and 0.36 respectively. Making certain assumptions, the mean proportions of fish-meal-N digested in the rumen were calculated to be 0.23 and 0.14 respectively for UT- and AT-straw diets. The values were not significantly different. Values for microbial flows based on DAP as marker were significantly lower, by about 25%, than those based on RNA.

scholarly journals Ruminal Ecology, Microbial Protein Synthesis and Milk Production in Lactating Dairy Cows Fed Glycerin-Based Diet: A Comparison Study on Chitosan Sources Supplementation

2020 ◽  
Author(s):  
Anuthida Seankamsorn ◽  
Anusorn Cherdthong ◽  
Sarong So ◽  
Metha Wanapat
Keyword(s):  
Protein Synthesis ◽  
Dairy Cows ◽  
Milk Production ◽  
Dry Matter ◽  
Nutrient Digestibility ◽  
Control Group ◽  
Microbial Protein ◽  
Microbial Protein Synthesis ◽  
Lactating Dairy Cows ◽  
Different Sources

The study compared the influence of chitosan sources on rumen fermentation, methane emission and milk production in lactating dairy cows fed a glycerin-based diet. Six, lactating Holstein-Frisian crossbreeds (410 ± 5.0 kg BW, 120 ± 21 day-in-milk), were arranged in a 3 x 3 replicated Latin square design. In addition to control, a 2% chitosan extract supplement and a 2% commercial chitosan supplement of dry matter intake were the treatments. The results denoted that no significant differences on daily dry matter, nutrients or estimated energy intake were noted when cows received different sources of chitosan. Nutrient digestibility was not influenced differently by extraction based or commercial chitosan supplements. The pH, temperature, ammonia nitrogen, blood urea and microbial count were similar among treatments. The different sources of chitosan supplements did not change the totals of volatile fatty acids, acetate and butyrate; in contrast, different chitosan sources influenced (P<0.05) propionate content. The ruminal acetate to propionate ratio was markedly (P<0.05) reduced with chitosan supplement, but no change appeared between sources of chitosan. At 4 hours after feeding, the methane estimation significantly decreased with the addition of chitosan supplementation (P<0.05) compared to the control group. The purine derivatives and microbial protein synthesis were not altered by the treatments. No significant differences existed on milk yield, milk composition or milk urea nitrogen when cows received different sources of chitosan (P>0.05). In sum, supplementing extracted chitosan showed more potential than did commercial chitosan for enhancing economic efficiency and recycling shrimp residues, therefore, reducing environmental waste.

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