Some relationships between wool production, nitrogen intake and digestible organic matter intake

1976 ◽  
Vol 16 (78) ◽  
pp. 64
Author(s):  
GE Robards ◽  
DE Tribe ◽  
R Thomas

Two experiments are described in which the wool production of Merino wethers receiving roughage rations of varying quantity and average crude protein content was examined. The results support a hypothesis that wool growth response to supplementation of low quality roughage is more closely related to the total digestible organic matter intake than to the total nitrogen intake. The second experiment demonstrates that in the short term the efficiency with which dietary nutrients are used for wool production depends upon the direction of liveweight change of the sheep.

1989 ◽  
Vol 113 (2) ◽  
pp. 249-253 ◽  
Author(s):  
D. N. Droushiotis

SUMMARYTwo small-grained cereals, Mulga oats and a triticale line, and two legumes, local vetch and local peas, were grown in pure stands and in mixtures at various cereal: legume seed ratios (20:80, 40:60, 60:40 and 80:20) for three successive cropping years, 1981/82 to 1983/84, at Laxia and Dromolaxia, Cyprus, in each year.The cereal pure stands produced, on average, more dry matter, 8·40 t/ha, and more digestible organic matter, 4·12 t/ha, than the legume pure stands, 3·68 and 2·18 t/ha, respectively. On average, total dry matter production decreased linearly as the seed proportion of the legume component in the mixture increased. The proportion of the legume in the harvested material was much lower than expected from the seed ratios. The highest proportion of legume was seen in the mixtures of peas with triticale and ranged from 8·1 to 35·5% at the various sowing rates. Digestibility and crude protein content were highest in the mixtures of triticale and peas.


1964 ◽  
Vol 15 (4) ◽  
pp. 676 ◽  
Author(s):  
LJ Lambourne

Estimates have been made of the feed intake of wethers that received implantations of 60 mg thyroxine every 3 months, and of untreated sheep, grazing together. The estimated intake of digestible organic matter (D.O.M.) by treated wethers was higher than that of controls in 24 out of 27 measurement periods. The difference in feed intake was least in the iirst month after implantation, when the treated sheep lost weight, and greatest in the second and third months when the treated sheep were regaining weight. The overall increase in intake resulting from thyroxine treatment (20–25%) was greater than the increase in wool production (7% greasy weight, 3-7 % clean weight), and the efficiency of wool production was therefore lower in thyroxinetreated wethers. From the relationships between feed intake and rate of weight change it was concluded that in the month after implantation, when pulse rates indicated a substantial rise in metabolic rate, the maintenance feed requirement was raised from about 560 g to about 780 g D.O.M. per day. Observations in two winters with recently shorn sheep gave estimates of maintenance requirements for untreated wethers ranging from 850 to 1300 g D.O.M. per day. During recovery from repeated thyroxine implantation the wethers gained in weight no more efficiently than the controls. The mechanism of action of exogenous thyroxine is discussed in the light of these and other data.


1971 ◽  
Vol 22 (2) ◽  
pp. 307 ◽  
Author(s):  
RH Weston

The voluntary feed consumption (VFC), liveweight increase, and wool growth of lambs, initially 9-10 weeks old and weighing 22 kg, were measured over 6 weeks when pelleted diets of differing protein content were offered. The crude protein contents of the diets, on a dry matter basis, were 11.7% (LP diet), 15.8% (MP diet), and 19.1 % (HP diet). The digestion of the HP and LP diets was studied, with use of markers, in similar lambs prepared with stomach fistulae. VFC, expressed as grams dry matter/day/kg body weight0.75, was 82 (SE�3) with the LP diet, 94�3 with the MP diet, and 97�4 with the HP diet. The dietary crude protein intakes were 110, 178, and 220 g/day with the LP, MP, and HP diets respectively and the corresponding quantities of crude protein (6.25 x nitrogen in forms other than ammonia) apparently digested in the intestines (DCP,) were 75, 134, and 179 g/day. The LP and HP diets provided about 12 and 23 g DCP1/lOO g digestible organic matter respectively; the value for the MP diet was estimated to be 18 g DCP1/100 g. The rates of liveweight increase were 153 � 16, 240�9, and 267�12 g/day with the LP, MP, and HP diets respectively. Wool production was the same with the MP and HP diets but lower with the LP diet. The level of intake of DCP1 and the DCP1/digestible organic matter ratio had little effect on the gross chemical composition of the lambs, as estimated indirectly from tritiated water space. The levels of essential amino acids in peripheral blood plasma were generally in the order HP diet > MP diet > LP diet. Digesta flow from the rumen and abomasum, rumen volume, ruminal volatile fatty acid concentration, and pH of ruminal digesta were similar with the LP and HP diets. It was concluded that a level of about 18 g DCP1/100 g digestible organic matter was adequate for the expression of maximum VFC and that concentrations in excess of this would have little enhancing effect on liveweight gain or wool production under conditions of ad libitum feeding.


1988 ◽  
Vol 39 (5) ◽  
pp. 881 ◽  
Author(s):  
PT Doyle ◽  
CE McLaren

Nine mature Merino wethers were fed three clover diets at 95% of previously measured intake under steady state conditions. The diets were mature subterranean clover (MSC), green subterranean clover (GSC) and persian clover (PC). The utilization of dietary N and S was studied for each feed.The ratios of digestible organic matter (DOM) to crude protein (CP) in the diets ranged from 3.9 to 5.5 : 1. The flow of microbial crude protein (MCP) from the abomasum was only 34 g day-1 in sheep given MSC compared to 77 g day-1 for GSC and 85 g day-1 for PC. However, the calculated efficiencies of MCP synthesis were 230-250 g MCP per kg OM apparently digested in the rumen for the three clovers. Despite the similar efficiencies of MCP synthesis, the ammonia-N (30 mg l-1) and sulfide-S (220 8g l-1) concentrations in the rumen of sheep fed MSC were low. The concentrations for the the other clovers were ammonia-N 90-110 mg l-1 and sulfide-S 730-1770 8g l-1. The amount of CP apparently digested in the intestines (DCPi) was only 31 g day-1 in sheep given MSC compared to 100 g day-1 and 81 g-1 in those fed GSC and PC, respectively. While this indicates that protein insufficiency in the tissues may have limited the intake of MSC, the DCPi values per unit of DOM intake were 150,210 and 150 g kg DOM-1 for MSC, GSC and PC, respectively. Sheep excreted more N and S (% of intake) in faeces when given MSC compared to GSC or PC.The sheep were in positive apparent balance for N and S when fed GSC or PC, but were mobilizing these nutrients from tissues at the low intakes of DOM, N and S with MSC. The wool growth rates and amounts of N and S incorporated into wool when MSC was fed were about half the other two feeds.These results are discussed in relation to other work on the utilization of N and S by sheep and likely effects of this on the intake of the feeds.


1983 ◽  
Vol 100 (1) ◽  
pp. 43-62 ◽  
Author(s):  
Elisabeth Grenet

SUMMARYThe digestibility, the voluntary intake and the nitrogen balance of 108 diets corresponding to 94 silages prepared from 20 fresh crops were measured in growing sheep. Series of silages were made from the same fresh forage. Each series included two controls: a direct-cut silage without additive and a direct-cut silage with formic acid, with a variable number of experimental silages with different additives.Rumen ammonia concentration, measured on rumen-fistulated sheep, decreased when an additive was used. It increased with nitrogen intake and was inversely related to the organic-matter digestibility and the crude-fibre digestibility. It varied with the silage composition.The crude-protein digestibility of direct-cut silages without additives was similar to or slightly higher than the crude-protein digestibility of the fresh crops. The addition of formic acid depressed the digestibility, but the addition of formaldehyde decreased it even more. The urinary nitrogen loss was higher for silages without additive than for the fresh crops and was decreased by the addition of formic acid. The addition of formaldehyde to formic acid had an additive effect.Retained nitrogen was lower in silages without additives (12% of nitrogen intake) than in parent crops (15·7%). It increased when formic acid (15·8%) was added. The addition of formaldehyde at a low rate (1·5 l/t green fodder) to the formic acid did not increase the nitrogen retention whether expressed in g/day or as percentage of nitrogen intake, but the addition of formaldehyde at a high rate (3·5 l/t green fodder) to formic acid decreased nitrogen retention. The other additives based on cereals or whey did not improve the nitrogen balance compared with formic acid. Nitrogen retention differed according to plant species.Retained nitrogen increased with digestible organic-matter intake and nitrogen intake. It increased with the silage water-soluble carbohydrate content. The higher the silage fermentation product content (ammonia, lactic acid, propionic acid), the lower the retained nitrogen. It appears that the nitrogen value of silages can be high provided that the silages are well preserved and that excessive protein breakdown is avoided.


2008 ◽  
Vol 19 (3) ◽  
pp. 252 ◽  
Author(s):  
O. NISSINEN ◽  
P. KALLIAINEN ◽  
L. JAUHIAINEN

The development of the yield and nutritive value of timothy (Phleum pratense L.) both in the primary growth and in the regrowth were studied at MTT Plant Production Research, a unit of MTT Agrifood Research Finland, in Rovaniemi (66°35´N) in 1999–2001. The dry matter yield and leaf:stem ratio were measured from the crop samples, and the contents of crude protein and organic matter digestibility of both whole plant samples and leaf and stem fractions were analysed. In primary growth, the most rapid increase of dry matter, 220–240 kg ha-1 per day, was measured around the beginning of the heading stage. There was a very strong positive correlation between the proportion of stems and the amount of dry matter in the primary yield. The daily growth rate of the regrowth was less than half of that of the primary growth. The fastest decrease, 1 percentage unit per day, in crude protein content was measured at the pasture stage (4–5-leaf stage). During the entire sampling period, the average daily decline in crude protein content in the primary growth of timothy was 0.65 percentage units. The main cause for the rapid decline in crude protein content was the high proportion of stem matter and its low protein content. In the regrowth, during the last four weeks before the harvest, the average daily decline in crude protein content was 0.28 percentage units.The average decline in organic matter digestibility from early pasture stage to late silage stage was 0.9 percentage units per day. The most remarkable change was noticed at the growth stage of timothy when about the half of stems were heading and it was then that the digestibility decreased by more than one percentage unit per day. The rapid decline in organic matter digestibility was due to the low digestibility of stem matter. The daily change in forage digestibility in the regrowth was very small, on average 0.11%.;


2009 ◽  
Vol 49 (12) ◽  
pp. 1100
Author(s):  
B. J. McGuirk

Early work in the 1950s on the wool growth response of sheep from diverse genotypes for wool production in response to varying planes of nutrition at pasture did not show the significant genotype × environment interactions exhibited in later pen studies with the same or very similar genotypes. However, this early study used a log-transformation on all traits to adjust nutritional effects for scale. Re-analysis of the original (i.e. untransformed) data shows that superior genetic merit for clean fleece weight, different sire progeny groups or selection flocks is more apparent when hogget ewes are fed a high plane of nutrition at pasture. However, only in the case of flocks was the interaction statistically significant, and this interaction was insignificant when data were either log-transformed, or when an appropriate test that accounts for scale-type effects was applied. When left untransformed, the data are, thus, in agreement with the subsequent pen studies that examined data on untransformed clean wool production.


2018 ◽  
Vol 70 (1) ◽  
pp. 29-36
Author(s):  
F.C.D. Araújo ◽  
M.G. Cruz ◽  
J.C.C. Balieiro ◽  
M.L. Menezes ◽  
C.G. Moreira ◽  
...  

ABSTRACT The aim of this study was to investigate the effect of odontoplasty on apparent digestibility of diet for horses, consumption time, and particle size of feces. Nine horses were used, aged 14.5±3.3 years and weightng 531±38.7kg. The diet consisted of 1.5% of live weight (LW) in Tifton 85 hay and 0.75% of LW in concentrate for both assays. The experiment consisted of two tests of apparent digestibility using the method of total collection, before and after the odontoplasty, where the consumption time of hay and concentrate was also evaluated and the particle size of the feces was analyzed. An effect (P<0.05) of odontoplasty on the apparent digestibility coefficients of dry matter, organic matter, crude protein, neutral detergent fiber and acid detergent fiber was observed. Effect of the consumption time for the concentrate (P<0.05) was observed, but not for the forage (P<0.05). There was more retention (P<0.05) of the fecal particles in the sieves of bigger granulometry. The odontoplasty increases the digestibility of dietary nutrients and feces particle size, without changing feces quality. Animals after the procedure have shorter concentrate consumption time.


2006 ◽  
Vol 34 ◽  
pp. 109-115
Author(s):  
Eva Schlecht ◽  
Andreas Susenbeth

SummaryAn equation predicting organic matter digestibility (OMD) of the diet from faecal crude protein content (FCP) was established by Lukas (2002) with data from cows fed various diets based on roughage of temperate origin. The suitability of this equation to predict OMD of tropical roughages was tested with data from grazing and stall-fed cattle, sheep and goats. The correlation between measured OMD and that estimated from the average FCP of a group of animals consuming the same diet was r=0.91, and the deviation between estimated and measured values averaged 6%. Poor estimates were obtained for feeds with high biological tannin activity. Using the equation provides an easy assessment of OMD of tropical roughages that do not contain biologically traceable amounts of anti-nutrients.


1962 ◽  
Vol 58 (3) ◽  
pp. 387-391 ◽  
Author(s):  
J. H. Topps

1. In two continuous digestibility trials carried out in 1960 and 1961, groups of three wether sheep were fed on oven-dried herbage which had been selectively collected from natural pastures during December 1959 to March 1960 and December 1960 to March 1961. The organic matter digestibility and the digestible crude protein content of the herbage and the nitrogen concentration in faeces were measured over periods of 5 days. The fresh faeces of dairy cattle grazing the natural pastures were regularly sampled and analysed. Regressions of organic matter digestibility and digestible crude protein content on faecal nitrogen were evaluated. From these equations and the composition of the dairy cattle faeces the digestibility of the herbage grazed was calculated.2. The herbage consumed by the cattle had a significantly higher organic matter digestibility and digestible crude protein content than the collected material. This difference, which increased as the season progressed, indicates that dairy cattle became increasingly selective in their grazing as the pasture deteriorated in quality.3. There was a marked yearly difference in digestibility-faecal nitrogen relationships and in the quality of the consumed forage. The grass eaten in 1959-60 had a higher digestibility and lower digestible crude protein content than in the following year. These differences may be part attributable to a seasonal difference in rainfall.4. The organic matter digestibility of the grazed herbage ranged from 52·71 to 65·03% and the digestible crude protein content from 3·08 to 7·43% For milk production, the herbage consumed is low in digestible protein in relation to the total amount of digestible nutrients.


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