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

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.

2001 ◽  
Vol 2001 ◽  
pp. 184-184
Author(s):  
A.R.J. Cabrita ◽  
A.J.M. Fonseca ◽  
C. Sampaio ◽  
E. Gomes ◽  
R.J. Dewhurst

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.


1993 ◽  
Vol 120 (2) ◽  
pp. 251-263 ◽  
Author(s):  
L. A. Sinclair ◽  
P. C. Garnsworth ◽  
J. R. Newbold ◽  
P. J. Buttery

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.


2010 ◽  
Vol 39 (5) ◽  
pp. 1141-1145 ◽  
Author(s):  
Alexandre Lima de Souza ◽  
Rasmo Garcia ◽  
Luciano da Silva Cabral ◽  
Mara Lúcia Albuquerque Pereira ◽  
Rilene Ferreira Diniz Valadares

It was evaluated nitrogen compounds and microbial protein synthesis in heifers fed diets containing coffee hulls (0.0; 8.75; 17.25; and 26.25% of dry matter) replacing ground corn concentrate at the following levels of coffee hulls in the total diet dry matter: 0.0, 3.5, 7.0 or 10.5%. It was used 24 crossbreed heifers (7/8, 15/16 and 31/32 Holstein-Zebu), which were distributed in a random block design made up accordingly to the weight of the animals. Spot samples of urine were colleted aproximatelly four hours after morning feeding and were used to estimate microbial protein synthesis by using urine purine derivatives. It was not observed effect of coffee hull levels in the diet on total nitrogen intake (160 g/day) and nitrogen excretion in the urine (87.4 g/day). The inclusion of coffee hull in the diet linearly increased nitrogen excretion in feces, as well as nitrogen balance. There was linear reduction in urinary excretion of allantoin, in total purine derivative and absorbed purine, which reduced 0.715, 0.873, and 0.954 mmol/day to each coffee hull unity added to the concentrate, respectively. Coffee hull altered microbial protein synthesis, which reduced in 0.687 g/day to each coffee hull unity added to the concentrate. Reduction in microbial protein synthesis can reduce weight gain in heifers fed coffee hulls.


1984 ◽  
Vol 51 (1) ◽  
pp. 77-83 ◽  
Author(s):  
A. B. McAllan ◽  
R. H. Smith

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.


Author(s):  
Anuthida Seankamsorn ◽  
Anusorn Cherdthong ◽  
Sarong So ◽  
Metha Wanapat

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.


1980 ◽  
Vol 31 (1) ◽  
pp. 163 ◽  
Author(s):  
J Leibholz

Nine Friesian calves between 11 and 30 weeks of age were fed on diets based on barley supplemented with 0, 1.75 or 3.5 % urea or with meat meal. In a further experiment a purified diet was supplemented with 3-5.25 % urea and 20-50% wheat straw. The replacement of meat meal by urea reduced the flow of nitrogen to the duodenum and the apparent absorption of amino acid in the intestines. It was calculated that diets containing no meat meal would be limiting the growth of calves by a deficiency of sulfur amino acids and possibly threonine. With purified diets it was also calculated that the sulfur amino acids would be the first limiting amino acids for growth. The apparent digestion of amino acids in the small intestine varied from 66 to 76% for diets containing at least 1.8% nitrogen. The apparent digestion of essential amino acids was greater than that of non-essential amino acids. A nitrogen content of 1.8 % as urea in a purified diet was sufficient to maximize the efficiency of microbial protein synthesis in the rumen to 23-24 g nitrogen per kg of dry matter fermented. This is equivalent to 1.7 g nitrogen per MJ of metabolizable energy in the diet and corresponds to a concentration of ammonia in the rumen of 120 mg/l. The dietary nitrogen content required in barley and urea diets for maximum microbial protein synthesis was greater than with purified diets owing to the incomplete breakdown of the nitrogen in barley in the rumen. The efficiency of microbial protein synthesis in the rumen was similar for diets containing 8.3-11.0 MJ of metabolizable energy per kg of diet. The apparent digestion of a-linked glucose polymers in the rumen was lower for diets containing 1.3 % nitrogen than for those containing at least 1.8 %. As the metabolizable energy content of diets increased, there was a decrease in the apparent digestion of a-glucose polymers in the rumen.


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