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.

Wool growth of pregnant and lactating Merino ewes

1985 ◽  
Vol 105 (3) ◽  
pp. 613-622 ◽  
Author(s):  
V. H. Oddy
Keyword(s):  
Organic Matter ◽  
Fibre Diameter ◽  
Wool Fibre ◽  
Total Plasma ◽  
Wool Growth ◽  
Digestible Organic Matter ◽  
Pregnancy And Lactation ◽  
The Difference ◽  
The Relationship ◽  
Growth Deficit

SUMMARYThe wool production of pregnant, lactating and non-pregnant, non-lactating (dry) Merino ewes eating one of three diets: chaffed oaten hay (OH), chaffed lucerne hay (LH), and a 50/50 (w/w) mixture of OH and LH, was determined. Measurements were made for 2 months prior to mating, during pregnancy and for 3 months after lambing, and for the dry ewes over the same period.Production of clean wool (Y, g/day) by dry ewes was linearly related to digestible organic matter intake (X, g/day):Y = 0·0301 X - 3·34, r = 0·97.Clean wool growth was significantly less (P < 0·01) than dry ewes in the 4th and 5th month of pregnancy and throughout lactation. During pregnancy the total deficit in clean wool growth (calculated as the difference between observed wool growth and that expected on the basis of the relationship between feed intake and clean wool growth of dry ewes) was 456 g for ewes bearing a single lamb and 578 g for those bearing twins, with no difference between diets. In lactation the total clean wool growth deficit increased as milk production increased, and for every litre of milk produced there was a deficit of 12 g clean wool.Wool fibre diameter was reduced during the 1st month of lactation. There was no consistent effect of pregnancy or lactation on the number of wool follicles per mm2, the ratio of primary plus secondary to primary wool follicles, or on the thickness of skin on the midside.Digestibility of dietary organic matter (DOM) was reduced during the last 3 months of pregnancy, and the first 2 months of lactation. However, this was insufficient to account for the magnitude of the decrease in wool growth seen during pregnancy and lactation.Wool sulphur content increased during pregnancy (P < 0·001), but not during lactation. The relationship between total plasma cyst(e)ine concentration and DOM intake during pregnancy was similar to that in dry ewes, but during lactation total plasma cyst(e)ine concentration was less than expected. It was calculated that during pregnancy the amount of sulphur saved through reduced wool growth was greater than that deposited in the conceptus, and during lactation the amount of sulphur saved in reduced wool growth matched that excreted as milk.These results are discussed in relation to control of wool growth during pregnancy and lactation.

Effect of time of joining and rate of stocking on the production of Corriedale ewes in southern Victoria. 3. Wool growth and the composition and availability of pasture

1975 ◽  
Vol 15 (73) ◽  
pp. 159 ◽  
Author(s):  
PA Kenney ◽  
IF Davis
Keyword(s):  
Fibre Diameter ◽  
Late Pregnancy ◽  
The Other ◽  
Early Lactation ◽  
Stocking Rate ◽  
Wool Production ◽  
Wool Growth ◽  
The Mean ◽  
Brome Grass ◽  
Stocking Rates

A study was made during a three year period (1 968-1 970) of wool production by a flock of 540 ewes grazing annual pasture at Werribee, Victoria. The ewes were stocked at three rates (5, 7 1/2 and 10 ewes ha-1) and lambed between July 6 and August 20 or between September 10 and October 29 each year. Fibre diameter and length of wool samples were measured in 1968, 1969 and 1970 ; in 1970 growth of greasy wool was calculated from staples of dye-banded wool. Wool growth was reduced in all ewes during late pregnancy and early lactation but was not affected during late lactation in ewes lambing in September. The proportion of tender fleeces from all ewes was greater in 1970 and the weight of fleeces from only those ewes bearing single lambs was less in all years for ewes lambing in July than for ewes lambing in September. More ewes were barren and fewer ewes had twins in July and consequently the mean fleece weights of all ewes from both groups were similar. Fleeces from ewes stocked at 10 ha-1 were lighter, shorter and finer than fleeces from ewes stocked at 5 and 7 1/2 ha-1, but the proportion of tender fleeces did not differ between the groups. Wool production of ewes stocked at 5 and 7 1/2 ha-1 increased from 1968 to 1970, whereas that of ewes at 10 ha-1 did not. This was associated with differences in pasture availability and composition. At 10 ewes ha-1 less pasture was present in winter and spring in 1970 than in 1968, whereas at the other stocking rates it was greater. In 1970 the density of weeds in autumn was greater and in spring more silver grass (Vulpia spp.) and less brome grass (Bromus spp.) was available at the high stocking rate.

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.

Influence of clipping regime and silage quality on the performance of pregnant and lactating ewes

1989 ◽  
Vol 1989 ◽  
pp. 55-55
Author(s):  
Heather J Black ◽  
D H B Chestnutt
Keyword(s):  
Organic Matter ◽  
Birth Weight ◽  
Crude Protein ◽  
Dry Matter ◽  
Late Pregnancy ◽  
Digestible Organic Matter ◽  
Silage Quality ◽  
Ad Libitum ◽  
Additional Influence ◽  
Voluntary Food Intake

Winter clipping of breeding ewes has given variable increases in lamb birth weight associated mainly with increased ewe voluntary food intake (Rutter, Laird and Broadbent, 1972; Vipond, King, Inglis and Hunter, 1987). The requirement for energy is greatest during the last six weeks of pregnancy but increasing uterine occupation of rumen volume may limit the ewe's ability to increase intake after clipping in late pregnancy. The additional influence of forage quality on intake after clipping is not clear. The present experiment was designed to study the independent and interacting effects of clipping regime and silage quality on lambing performance.Sixty Greyface ewes of uniform age were individually penned 14 weeks before lambing. Precision chop silage offered ad libitum was either early cut [188.3 g dry matter (DM)/kg, 155.7 g crude protein (CP)/kg DM, 740 g digestible organic matter (DOM)/kg DM] or late cut (184.5 g DM/kg, 100.9 g CP/kg DM, 689 g DOM/kg DM). For all treatments concentrate feeding was introduced 7 weeks before lambing, on an increasing scale to provide a total of 21 kg/ewe. Silage type was factorially arranged with 6 clipping regimes.

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.

Whole wheat grain feeding of Merino ewes. 3. Influence of level of wheat and vitamin A on wool growth in pregnancy and lactation

1976 ◽  
Vol 16 (78) ◽  
pp. 49 ◽  
Author(s):  
WR McManus ◽  
JA Reynolds
Keyword(s):  
Growth Rate ◽  
Vitamin A ◽  
Fibre Diameter ◽  
Late Pregnancy ◽  
Control Group ◽  
Whole Wheat ◽  
Wool Growth ◽  
Pregnancy And Lactation ◽  
Wool Yield ◽  
The Relationship

In experiment 1, ewes were fed three levels of wheat in pens, with or without vitamin A, from joining to weaning. The wheat levels ranged from 3.4 to 4.6 kg head-1 week-1. Control groups were run on native pasture. In experiment 2 three levels of wheat, which ranged from 3.9 to 7.1 kg head-1 week-1. were fed to ewes from joining to weaning. At each wheat level two groups were fed wheat in pens (wheat/ pen); another group was fed wheat in small paddocks (wheat/paddock). One of the wheat/pen groups received vitamin A. A control group was run at pasture. Vitamin A had no effect on wool traits except on wool yield in experiment 2. Clean wool weight and staple length increased linearly with increasing wheat intakes in both experiments. The relationship between fibre diameter and wheat level was linear in experiment 1 and curvilinear in experiment 2. In experiment 2 there were differences between wheat/pen and wheat/paddock groups in all the wool traits measured. In experiment 1, wool growth rate was reduced by 40 per cent in the wheat groups and by 44 per cent in the pasture groups during late pregnancy and lactation. In experiment 2, compared with early pregnancy, wool growth rate was reduced by 11 per cent and 31 per cent in the wheat groups during late pregnancy and lactation respectively.

Grazing management of reproducing ewes affects staple strength

2000 ◽  
Vol 40 (6) ◽  
pp. 783 ◽  
Author(s):  
S. M. Robertson ◽  
G. E. Robards ◽  
E. C. Wolfe
Keyword(s):  
Fibre Diameter ◽  
Late Pregnancy ◽  
Staple Fibre ◽  
Grazing Management ◽  
Nutritional Management ◽  
Early Lactation ◽  
Wool Growth ◽  
Pregnancy And Lactation ◽  
Staple Strength ◽  
Lamb Growth

A grazing study was conducted on irrigated pastures to assess the influence of manipulating the availability of green pasture at different stages of pregnancy and lactation on the staple strength of broad-wool Merino ewes lambing in July. Sheep subjected to different treatments produced wool ranging between 14 and 48 N/ktex for single-rearing and 22 and 53 N/ktex for non-lambing ewes. Single-bearing/rearing ewes produced wool of strength +4.7 (P>0.05) to –23 N/ktex (P<0.001) in comparison with non-lambing ewes. Reproduction was associated with a reduction in staple strength of 51, 24 and 9% for ewes grazed throughout the experiment at low, medium and high pasture levels, respectively. A staple strength greater than 40 N/ktex was achieved in single-rearing ewes which grazed high pasture mass throughout pregnancy and lactation, during late pregnancy and early lactation, or during mid-pregnancy. Single-rearing ewes, which grazed low pasture biomass throughout either mid, late or all of pregnancy, or during lactation, produced wool with staple strength less than 30 N/ktex. In comparison to grazing the medium pasture allowance throughout the experiment, manipulation of pasture availability had relatively small effects on lamb growth and average fleece measurements, compared with the effects on staple strength. The exception was ewes grazing only the low pasture allowance. The interaction between reproduction and nutritional management influenced staple strength by altering the minimum fibre diameter and the uniformity of along-staple fibre diameter and rate of wool growth. It was concluded that managing pasture availability to promote a uniform along-staple fibre diameter or rate of wool growth can prevent reductions in staple strength associated with reproduction.

Effects on wool production during pregnancy and lactation of twice daily abomasal supplementation with casein or methionine and cystine

1978 ◽  
Vol 18 (90) ◽  
pp. 52 ◽  
Author(s):  
AJ Williams ◽  
RN Tyrrell ◽  
AR Gilmour
Keyword(s):  
Amino Acids ◽  
Fibre Diameter ◽  
Late Pregnancy ◽  
Similar Response ◽  
Early Lactation ◽  
Wool Production ◽  
Wool Growth ◽  
Pregnancy And Lactation ◽  
Sulphur Amino Acids ◽  
Sorghum Grain

The responses in wool production of Merino ewes to abomasal supplements of casein (56 g day-1) and of a mixture of methionine and cystine were measured during late pregnancy and early lactation. The mixed supplement provided equal quantities of the sulphur amino acids as the casein. The ewes were offered sufficient quantities of a diet of sorghum grain/lucerne hay (in the ratio 7 : 3 by weight) to maintain maternal liveweight. During the final four weeks of pregnancy and the first six weeks of lactation, the cassin supplement increased wool growth (826 vs. 639 g cm-2 day-1). A similar response was observed for fibre diameter (1 9.7 vs. 18.5 pm : P < 0.05). Wool production and fibre diameter did not differ between the ewes supplemented with methionine and cystine and the control ewes during this same period. The ewes supplemented with methionine and cystine produced wool with the greatest sulphur content, and this trait was least in the wool from the control ewes (3.84 vs. 3.64 vs. 3.49: P < 0.05). We concluded that the availability of the sulphur amino acids was not primarily limiting wool production in pregnant/lactating ewes.

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