Factors associated with the rate of growth of clean wool on grazing sheep

1992 ◽  
Vol 43 (2) ◽  
pp. 265 ◽  
Author(s):  
HA Birrell
Keyword(s):  
Organic Matter ◽  
Physiological State ◽  
Growth Management ◽  
The Other ◽  
Factors Associated ◽  
Wool Growth ◽  
Hourly Rate ◽  
Digestible Organic Matter ◽  
Two Factors ◽  
Grazing Period

In a grazing study that spanned 2.5 years, the rate of clean wool growth (Wi, g/day) in 4 week periods on Corriedale wether sheep was measured on each side of the animal with dyebands that were applied, alternately, at 2 week intervals. The observations (n = 224) on wool growth from 3 contiguous periods Wi = 1, 2 and 3 with the middle overlapping the other two periods, were related to either the daily rate of organic matter intake (OMI, g/day), the digestible organic matter intake (g DOMI/day), the hourly rate of OMI (IR, g OMI/h) or the hourly rate of digestible organic matter intake (DR, g DOMI/h) in linear or quadratic expressions. The intake data were collected every 4 weeks over the 3 days that correspond to days 6 to 8 of W1. The variance accounted for in each of W1, W2 and W3 increased in the order OMI<DOMI<IR<DR. DR accounted for 33.2% of the variance in W1 with a significant quadratic fit (P < 0.01) and 24.3% and 7.8% with linear fits against W2 and W3, respectively. A relationship that comprised five factors and accounted for 68% of the variance in W1 was developed by nonlinear regression. Three factors that were associated with nutritional aspects, the hourly rate of digestible organic matter intake (DR, g DOMI/h), the organic matter digestibility (OMD %) and the average organic matter intake in a grazing period (M, g OMI/grazing period) accounted for 54.9% of the variance in W1 while the other two factors that were associated with the physiological state of the animal, fleece-free liveweight change (C, g/day) and the fleece-free liveweight (L, kg) accounted for a further 13.1% of the variance of W1. The study suggests that factors associated with phenomena within a daily period may have important effects on wool growth. Management aspects are discussed.

Utilization of clover diets by sheep. 2. Intake, digestion and utilization of nitrogen and sulfur

1988 ◽  
Vol 39 (5) ◽  
pp. 881 ◽  
Author(s):  
PT Doyle ◽  
CE McLaren
Keyword(s):  
Organic Matter ◽  
Steady State ◽  
Growth Rates ◽  
Crude Protein ◽  
Subterranean Clover ◽  
The Other ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
Persian Clover

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.

Estimates of the energy required for maintenance by adult sheep 2. Grazing sheep

1963 ◽  
Vol 5 (1) ◽  
pp. 11-16 ◽  
Author(s):  
J. P. Langlands ◽  
J. L. Corbett ◽  
I. McDonald ◽  
G. W. Reid
Keyword(s):  
Organic Matter ◽  
Energy Cost ◽  
Functional Relationship ◽  
Adult Sheep ◽  
Maintenance Requirement ◽  
Digestible Organic Matter ◽  
Faecal Nitrogen ◽  
Grazing Period ◽  
The Mean ◽  
Maintenance Requirements

SUMMARYThe mean daily digestible organic matter intake (D) of each of 47 adult sheep during a grazing period of mean length 48 days was estimated by the chromium sesquioxide/faecal nitrogen technique. Mean live-weights (W) and mean daily weight gains (G) were also measured.The regression of D on W and G, and the underlying or functional relationship between D, W and G were both estimated. From the underlying relationship, the preferred equation, the maintenance requirement of a 100 lb. sheep at pasture is estimated to be 1·02 lb. digestible organic matter daily. This value is 24% higher than the corresponding value for housed sheep obtained previously by us.This result is compared with other estimates of the energy cost of grazing and it is concluded that further work is needed in order to define those circumstances which elevate the maintenance requirements of grazing animals.

Stimulation of wool growth by thyroxine implantation. II. Feed intake of grazing Merino wethers treated repeatedly with thyroxine.

1964 ◽  
Vol 15 (4) ◽  
pp. 676 ◽  
Author(s):  
LJ Lambourne
Keyword(s):  
Organic Matter ◽  
Feed Intake ◽  
Sheep Grazing ◽  
Wool Production ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
The Difference ◽  
Maintenance Requirements ◽  
Substantial Rise ◽  
Stimulation Of

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.

Effects of shelter, exposure and level of feeding over winter on the productivity of Welsh Mountain ewes and lambs

1973 ◽  
Vol 17 (1) ◽  
pp. 21-32 ◽  
Author(s):  
W. I. Robinson ◽  
W. Brown ◽  
I. A. M. Lucas
Keyword(s):  
Weight Loss ◽  
Body Weight ◽  
Organic Matter ◽  
Live Weight ◽  
Outdoor Exposure ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
Maintain Body Weight ◽  
Fourth Experiment ◽  
Different Levels

SUMMARYPregnant Welsh Mountain ewes were kept over winter on a hill. All were penned individually, either in a shed or out of doors. In Experiments 1 and 2 different levels of digestible organic matter (DOM) were given in each environment and in Experiment 3 only a single level was offered. In Experiment 2 all ewes were grazed together after lambing; in Experiment 3 some from each treatment were moved to a shed after lambing and their milk yields recorded between 10 and 15 days later.In a fourth experiment on low land, pregnant ewes were either housed or kept in an exposed or a sheltered paddock. All were grazed together after lambing.The results indicated that the requirement of indoors penned sheep to maintain body weight and produce a single lamb is 9·5 g DOM/kg live weight per 24 hr at 16 weeks pre-partum, rising to 15·0 g DOM/kg live weight per 24 hr at 1 week pre-partum. A 10% weight loss during pregnancy would be expected in ewes receiving 75 to 80 % of these requirements. Low intakes during pregnancy reduced wool growth and lamb birth weights.Outdoor exposure reduced pre-partum ewe weight by about 1·5 kg, and so was equivalent to a 10% reduction in daily DOM intake. The magnitude of this effect was not changed significantly by level of feeding. Exposure did not affect wool growth and its influence on lamb birth weight and growth was variable.

Lablab (Lablab purpureus) and lupin (Lupinus angustifolius) seeds as supplements for sheep fed low quality roughage

1998 ◽  
Vol 38 (1) ◽  
pp. 23
Author(s):  
R. M. Dixon ◽  
E. S. Garcia ◽  
J. A. Domingo ◽  
J. H. G. Holmes
Keyword(s):  
Organic Matter ◽  
Dry Matter ◽  
Nutritional Value ◽  
Synthetic Fibre ◽  
Rumen Fluid ◽  
Lupinus Angustifolius ◽  
Lablab Purpureus ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
Ad Libitum

Summary. The seeds of lablab (Lablab purpureus) and lupin (Lupinus angustifolius) were investigated as supplements for young sheep. In experiment 1, rumen-cannulated sheep were offered low quality roughage ad libitum alone or supplemented with about 5, 10 or 20 g/kg liveweight whole lupin or lablab seed. Rumen ammonia concentrations were increased by each level of both supplements, and the increases were greater with lupins than with lablab. The pH of rumen fluid was decreased by both supplements, particularly when the higher levels were fed. Dry matter of broken seeds of both legume species rapidly disappeared from synthetic fibre bags incubated in the rumen. Roughage dry matter disappearance from synthetic fibre bags decreased (P<0.05) when 20 g/kg liveweight lupins was fed, and this level of both supplements reduced (P<0.05) roughage intake. Total dry matter intake was increased more by lablab than by lupins, but dry matter and organic matter digestibility tended to be increased to a lesser extent by lablab. Overall, digestible organic matter intake and liveweight gain were increased to similar extents by both supplements. Wool growth was lower (P<0.05) with lablab than lupins, particularly at the highest level of supplementation, suggesting that availability of some amino acids was lower with lablab supplement. In experiment 2, rumen-cannulated sheep were fed low quality roughage ad libitum and supplemented with about 10 g/kg liveweight of either lupin or lablab seed. Lectins and protease inhibitors present in the lablab seed disappeared rapidly from synthetic fibre bags incubated in the rumen. In conclusion the nutritional value of lablab seed as a supplement for sheep fed low quality roughage was similar to that of lupin seed for liveweight gain, but was lower for wool growth.

The food conversion efficiency in lambs of two crosses of sheep

1967 ◽  
Vol 7 (26) ◽  
pp. 199 ◽  
Author(s):  
ME Bourke
Keyword(s):  
Growth Rate ◽  
Organic Matter ◽  
Conversion Efficiency ◽  
Animal Tissue ◽  
Food Conversion ◽  
Factors Associated ◽  
Digestible Organic Matter ◽  
High Level ◽  
Food Conversion Efficiency

The experiment investigated factors associated with differences in growth rate from birth to seven weeks, by two crossbreeds of lamb. The Dorset Horn x Border Leicester-Merino grew at 0.18 kg per day, and the Dorset Horn x Merino grew at 0.14 kg per day (P<0.001) although both crosses consumed the same digestible organic matter intake. Thus the second cross was significantly more efficient (P<0.05) than the first cross. Two levels of milk were also fed to both crosses and, although the high level improved growth rate (P <0.001), it did not effect the efficiency of conversion of food to animal tissue.

The effects of grazing intensity on herbage consumption and animal production: III. Dairy cows grazed at two intensities on clean or contaminated pasture

1969 ◽  
Vol 72 (2) ◽  
pp. 223-228 ◽  
Author(s):  
J. F. D. Greenhalgh ◽  
G. W. Reid
Keyword(s):  
Organic Matter ◽  
Dairy Cows ◽  
Dry Matter ◽  
Live Weight ◽  
Grazing Intensity ◽  
Milk Composition ◽  
The Other ◽  
Soluble Carbohydrate ◽  
Digestible Organic Matter ◽  
Carbohydrate Contents

SUMMARYOn three occasions in May—July one half of a ryegrass pasture was grazed intensively by cattle and the other was mown. In August and September these areas, designated fouled (F) and clean (C) respectively, were each strip-grazed by two groups of five cows. One group on each area had a herbage allowance of 11·4 kg dry matter per cow per day (C11 and F11) and the other 20·4 kg (C20 and F20).Before the August-September grazing the fouled area had 2·8% of its surface covered by faeces. After this grazing 23 % of the F n area and 34 % of the F20 area were classified as having been rejected by the cows. However, the upper parts of the sward on these rejected areas were in fact grazed. There were only small differences in N and soluble-carbohydrate contents between the herbages offered and rejected.Organic-matter digestibility (%) and intake (kg/cow per day) for the four groups were: C11, 73·0 and 10·5; C20, 74·9 and 11·7; F11 , 74·4 and 9·6; F20, 77·0 and 10·6. The C11 cows consumed all the herbage allowed to them, but the F11 rejected 13%. Digestible organic matter intake was affected more by grazing intensity than by fouling; this was the case also for milk yield, milk composition and the live-weight change of the cows.

Nutritional responses in wool growth by four Merino genotypes of differing wool growth performance

1994 ◽  
Vol 45 (6) ◽  
pp. 1171 ◽  
Author(s):  
GJ Lee ◽  
AJ Williams
Keyword(s):  
Organic Matter ◽  
Nutrient Intake ◽  
Regression Coefficient ◽  
Unit Area ◽  
Fibre Diameter ◽  
The Other ◽  
Wool Growth ◽  
Per Se ◽  
Relationship Of ◽  
The Relationship

Sheep from four Merino flocks, different in annual clean fleece production when grazed together, were offered a range of nutritional treatments to compare their ability to digest dietary organic matter (experiment 1) and to compare the relationships of wool growth and fibre diameter with nutrient intake (experiment 2). The sheep were selected from a finewool (Fl), a strong wool (S), and two medium-Peppin (MP6 and MP10) flocks. The nutritional treatments varied intakes of two pelleted diets-B and F. Diet B consisted of oat grain, lucerne chaff, and oaten straw, while diet F was as for B but fortified with fishmeal. The digestibility of both diets was negatively related to the level of intake, and there were some differences between the flocks in their ability to digest organic matter. Clean wool growth per unit area of skin was curvilinearly related (P < 0.001) to N intake, but was not influenced by diet per se. The regression coefficient for the relationship of clean wool growth with N intake and the estimated maximum wool growth rate of flock F1 were less than the other flocks. However, flock MP10 grew less wool than flocks S and MP6 at any given intake. Variation in (fibre diameter)2 accounted for 0.6 of the variation in wool growth, with responses in fibre diameter to intake being similar to those observed in wool growth. The responses in plasma cystine of the flocks to N intake differed, with the relationship for flock F1 being curvilinear and reaching a maximum at an intake of 27 g N day-1, while the responses of the other flocks were essentially linear. The relationships between plasma cystine level and wool growth differed between the flocks such that wool growth of sheep from flocks S and MP6 was more responsive to increased plasma concentration of cystine.

Development of Posterior Subcapsular Cataracts in Asthmatic Children

PEDIATRICS ◽  
1984 ◽  
Vol 73 (5) ◽  
pp. 626-630
Author(s):  
R. G. Bhagat ◽  
H. Chai
Keyword(s):  
Risk Factors ◽  
Bone Age ◽  
The Other ◽  
Systemic Steroid ◽  
Children At Risk ◽  
Steroid Administration ◽  
Asthmatic Children ◽  
Factors Associated ◽  
Systemic Steroid Therapy ◽  
Two Factors

Posterior subcapsular cataracts (PSCC) are known complications of systemic steroid therapy. Previous studies have not clearly identified the asthmatic children at risk for the development of PSCC. The possible factors associated with systemic steroid administration that may influence the development of PSCC in asthmatic children were evaluated: (1) duration of administered steroids, (2) dose, (3) number of steroid "bursts" in the preceding year, (4) degree of retardation of bone age, and (5) mode of administration (daily or alternate day) of steroids. Of the 40 asthmatic children requiring steroids, seven (17.5%) had PSCC. All of the children with PSCC had been receiving steroids on a daily or alternate-day basis for at least 2 years and all had markedly delayed bone age. Only one child with the concurrent occurrence of these two factors did not develop PSCC. None of the other risk factors considered could distinguish the group of patients with PSCC. It is concluded that asthmatic children receiving steroids for 2 years or longer and having markedly delayed bone age are at a greater risk for the development of PSCC.

Consequences of reproduction on the liveweight, fat depth, wool growth, and intake of grazing Merino ewes in the short and long term

1995 ◽  
Vol 35 (2) ◽  
pp. 153 ◽  
Author(s):  
GJ Lee ◽  
KD Atkins
Keyword(s):  
Organic Matter ◽  
Reproductive Cycle ◽  
Reproductive Performance ◽  
Fibre Diameter ◽  
Late Pregnancy ◽  
Annual Reproductive Cycle ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
Short And Long Term

Effects of the current and previous year's reproductive performance on liveweight, fat depth, pasture intake, and wool growth were estimated in breeding Merino ewes in each of 2 years and in 4 seasons corresponding with stages of the annual reproductive cycle. Ewes bearing multiple lambs were heavier in early pregnancy (autumn, by 1.5 kg) and in late pregnancy (winter, by 2.5 kg) than single-bearing ewes, with both being heavier than nonpregnant (dry) ewes in winter (by 1.7-4.2 kg). Pregnancy had no effect on fat depth or intake in autumn or winter. Lactating ewes were leaner (by 1.0-1.7 mm), had lower liveweights (by 6.4-8.6 kg), and had substantially higher intakes [by 286-348 g digestible organic matter intake (DOMI)/day] than non-lactating ewes. From summer to winter, ewes that had previously reared a lamb, or lambs, to weaning weighed less, were leaner, and had higher intakes than ewes that were previously dry. Pregnant ewes grew significantly less clean wool and grew it less efficiently (g wool/kg DOMI) in autumn (7-9% less) and winter (11-18% less) than non-pregnant ewes. Similarly, lactating ewes grew less wool (by 23-30%) less efficiently than ewes not suckling, the effect being greater in ewes with multiple lambs. Post-weaning, however, ewes that had reared a lamb to weaning grew significantly more wool (by 6-15%) up to 4 months post-weaning, although efficiency of wool growth was still impaired. The effects of reproductive status on the fibre diameter of wool reflected those for wool growth. Effects of reproduction on productivity are long term and recovery may not be achieved before the next reproductive cycle.

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