Urea and meat meal in the diets of ruminant calves - the sites of digestion and the nitrogen requirements for microbial protein synthesis

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.

1975 ◽  
Vol 15 (75) ◽  
pp. 460
Author(s):  
J Leibholz

Three experiments were conducted with 108 male Friesian calves to determine the effect of protein and energy in the diet on the concentration of free amino acids in the plasma. In experiments 1 and 2, the diets contained 12 to 21 per cent crude protein, with urea or meat meal as the protein supplement. The diets were fed with and without sulphur supplementation. In experiment 3, the metabolizable energy content of the diets was changed from 2.2 to 1.8 Mcal kg-1 by the addition of 20 to 60 per cent roughage from lucerne meal or ground straw to the diets. Blood samples were collected from all calves at 11 weeks of age, and the concentration of free amino acids in the plasma was measured. As the protein content of the diets increased, the percentage of essential amino acids of the total amino acids in the plasma increased. The percentage of essential amino acids was also greater in the calves fed meat meal than in those fed urea. These changes were mainly due to increased concentrations of the branched chain amino acids and decreased concentrations of glycine and glutamic acid. The supplementation of the diets containing urea with sodium sulphate increased the concentrations of cystine and methionine in the plasma. As the metabolizable energy intake of the calves increased there was an increase in the concentration of total amino acids in the plasma. Hence, the effect of protein and energy in the diet must be considered in studying the concentration of amino acids in the plasma.


1975 ◽  
Vol 85 (1) ◽  
pp. 93-101 ◽  
Author(s):  
D. G. Harrison ◽  
D. E. Beever ◽  
D. J. Thomson ◽  
D. F. Osbourn

SUMMARYThe effects of an altered rumen dilution rate (D) upon the molar proportions of volatile fatty acids (VFA) in rumen liquor, VFA production rate, microbial protein synthesis and carbohydrate digestion within the rumen were studied using adult wether sheep.Dilution rate and VFA proportions were unaltered by the infusion of up to 121 water/day into the rumen of sheep fed dried grass and concentrate (9:1). There was a small but significant (P< 0·05) increase in the rumen volume when the infusion rate was increased from 8 to 12 1/day.The intraruminal infusion of artificial saliva (41/day), or artificial saliva containing 4% or 8% w/v polyethylene glycol (PEG) caused a significant increase in D with an associated decline in the molar proportion of propionate (Pr) in the rumen liquor. A similar effect was obtained with the intraruminal infusion of 2·5% w/v sodium bicarbonate. The overall regression of Pr on D was highly significant: Pr = 32·5–82·1D;r= –0·99, P < 0·001.A diet of flaked maize: dried grass (6:4) was offered to three sheep each fitted with a rumen cannula and with a re-entrant cannula at the proximal duodenum. The intraruminal infusion (4 1/day) of artificial saliva containing 4% w/v PEG caused a significant (P< 0·01) increase in D and a significant (P< 0·01) depression in Pr in two animals. The dilution rate and Pr in the third animal were virtually unaltered by infusion. The regression of Pr on D for the three animals was highly significant: Pr = 34·8–136·8D; r = –0·98, P < 0·001. Each increase in D was associated with an increased flow of α-linked glucose polymer, total amino acids and total microbial amino acids into the small intestine and with an increased efficiency of microbial protein synthesis within the rumen.


2001 ◽  
Vol 2001 ◽  
pp. 28-28
Author(s):  
J.P. Russi ◽  
R.J. Wallace ◽  
C.J. Newbold

Peptides and to a lesser extent amino acids accumulate in rumen fluid in the early post feeding period and rapidly decline thereafter (Broderick & Wallace, 1988). Numerous studies have demonstrated benefits to feeding peptides, in terms of increased microbial growth in the rumen (Newbold, 1999). However, given that peptides will only be available in the rumen for a short time after feeding it may be necessary to match supply of peptides and energy in the rumen to maximise the stimulation in microbial activity. The objective of this study was thus to investigate if microbial protein synthesis in rumen fluid would be enhanced by a synchronous provision of peptides and energy.


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.


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.


2015 ◽  
Vol 36 (6Supl2) ◽  
pp. 4413
Author(s):  
Luis Gabriel Alves Cirne ◽  
Américo Garcia da Silva Sobrinho ◽  
Fernanda Carvalho Basso ◽  
Roque Takahashi ◽  
Thiago Henrique Borghi ◽  
...  

<p>The objective of this study was to evaluate intake, microbial protein synthesis, and nitrogen balance in lambs fed diets containing 0.00, 12.50, and 25.00% mulberry hay substituting the concentrate. Twentyfour Ile de France lambs at approximately 60 days of age, with a body weight of 15.48 ± 0.07 kg, were confined in individual stalls and slaughtered upon reaching 32 kg body weight. Only the intakes of ether extract and metabolizable energy decreased linearly (P&lt;0.05) as the participation of mulberry hay in the concentrate was increased. Nitrogen in the feces, expressed in g day–1 and g kg0.75 day–1, increased linearly (P&lt;0.05), whereas excretions (mmol day–1) of allantoin, total purines, and absorbed microbial purines, microbial production (g day–1) expressed in microbial nitrogen and microbial crude protein, and microbial efficiency expressed in g MN kg–1 RDOM–1 and g MP kg–1 of TDN decreased linearly as the level of hay in the diet was increased. Mulberry hay substituting the concentrate in diets for feedlot lambs reduces the microbial protein synthesis.</p>


1978 ◽  
Vol 91 (3) ◽  
pp. 543-550 ◽  
Author(s):  
V. K. Cilly ◽  
G. N. Lodhi ◽  
J. S. Ichhponani

SummaryCakes derived from Taramira (Eruca sativa), Raya (Brassica juncea), Toria (B. campestris var. toria) and yellow and brown sarson (B. campestris var. sarson) were evaluated for their contents of crude protein, true protein, essential amino acids, available carbohydrate and tannins. Feeding trials were also conducted to compare the suitability of these cakes with groundnut cake for broilers and White Leghorn chicks up to 4 weeks of age.The crude protein content of Taramira cake was 33% whereas all the other cakes contained 37–38%. True protein accounted for 80–83% of crude protein in all the varieties and albumin and globulin constitutes the bulk of protein. The critical amino acid content of all the brassica seed proteins was found to be higher than that of other vegetable proteins although varietal differences were observed with respect to a few essential amino acids. The hulls accounted for 19% of whole Brassica seed and their removal raised the concentration of protein from 39 to 46% and reduced the crude fibre content from 15 to 6% in the defatted meal. Tannin content was higher in Taramira (1·74%) than in all other varieties (1·0–1·4%) and the major quantity of it was localized in the endosperm. The average metabolizable energy content of all the mustard cakes was 9·62 and 8·75 MJ/kg for meat-type and egg-type chicks, respectively. The nutritive value of Taramira cake was poorer than that of other Brassica cakes or groundnut cake for supporting growth rate of chicks of either breed.


2020 ◽  
Vol 15 (2) ◽  
pp. 187-194
Author(s):  
N. N. Suryani ◽  
I. W. Suama ◽  
I. G. Mahardika ◽  
N.P. Sarini

The purpose of this study was to determine the effect of energy and protein levels on rumen fermentation, microbial protein synthesis of Bali cattle heifers. The study was conducted in Petang Village, Badung Regency, Province of Bali Indonesia on 12 Bali cattle heifers with initial body weight 193,67 ± 22,55 kg/head. The treatment given is four types of ration consists of different level of metabolizable energy (ME) and crude protein (CP): ME 2051.41 kcal/kg: 12.04% CP (Treatment A); ME 2107.79 kcal/kg : 13.05% CP (Treatment B); ME 2194.06 kcal/kg : 14.04% CP (Treatment C) and ME 2294.23 kcal/kg : 15.09% CP (Treatment D). Variables measured: nutrient intake, rumen fermentation, microbial protein synthesis and growth performance of Bali cattle heifer age of 18 month. This research was a randomized block design. The results showed that increase in ME to 2294.23 kcal /kg and 15.09% CP significantly (P <0.05) increased energy intake to 17,880.57 kcal /day and protein intake 686.56 g /day. Rumen fermentation was also highest (P <0.05) in treatment D seen from total VFA, propionic acid and butyric acid respectively 170.32 mMol, 28.52 mMol and 13.70 mMol. While acetic acid, methane and NGR significantly decreased (P <0.05) respectively 57.77 mMol, 18.38 mMol and 3.07. This resulted in the highest rumen microbial protein synthesis in treatment D which was 562.06 g / day so that it was able to produce the highest ADG too, which was 0.42 kg /day. This study concluded that giving rations containing ME 2294.23 kcal /kg and 15.09% CP increased rumen fermentation and microbial protein synthesis, resulting in the highest growth compared to lower levels.


1977 ◽  
Vol 28 (5) ◽  
pp. 917 ◽  
Author(s):  
H Dove ◽  
GR Pearce ◽  
DE Tribe

Male crossbred lambs weighing 12.5 kg (period 1), 20 kg (period 2) and 30 kg (period 3) were infused per abomasum with milk-based diets in which crude protein (CP) and energy contents were constant at a given Iiveweight, but in which the proportion of CP supplied as essential amino acids (EAA) varied from 120 to 876 g EAA/kg CP. Responses in liveweight gain, nitrogen balance and metabolizable energy (ME) intake (period 1 only) were measured. A number of lambs died while receiving diets containing very high or very low proportions of EAA. Possible reasons for these deaths are discussed. In all periods liveweight gains were greatest in lambs given the control diet (513 g EAA/kg CP). In period 1 this liveweight gain was close to that expected on the basis of energy intake, but in periods 2 and 3, liveweight gains on the control diets were less than anticipated. Reductions in liveweight gain were greater for diets containing low proportions of EAA than those containing high proportions. The infusion of diets containing low proportions of EAA markedly increased urinary nitrogen excretion. The effect of diets containing high proportions was less pronounced. As a result of these effects, lambs given the control diet had the highest daily nitrogen balance in all periods. Nitrogen balance was less severely affected by the dietary changes than liveweight gain, particularly with 30 kg lambs. It is suggested that the reduced retention of apparently digested nitrogen in diets other than the control diets reflected the unsuitability of the pattern of absorbed amino acids for protein synthesis. The effect of diet on the components of energy balance in period 1 was less pronounced than its effect on nitrogen balance. The metabolizability of apparently digested energy was lower in diets other than the control diet, especially those containing low proportions of EAA. This is attributed to the energy cost of increased urinary nitrogen excretion on such diets. Alternative interpretations of the results are discussed, and it is suggested that dietary amino acids will be utilized most efficiently for protein synthesis by the tissues of the lamb when essential and non-essential amino acids are provided in approximately equal proportions. There was no conclusive evidence that this optimum proportion was different for older lambs.


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.


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