Fat lamb studies in Victoria. II. The interaction between pre- and post-natal planes of nutrition on the production of wool and lambs by crossbred sheep

1957 ◽  
Vol 8 (5) ◽  
pp. 471 ◽  
Author(s):  
JC Papadopoulos ◽  
TJ Robinson
Keyword(s):  
Growth Rate ◽  
Ewe Lambs ◽  
Wool Growth ◽  
Breed Difference ◽  
Plane Group ◽  
Nutritional Environment ◽  
The Mean ◽  
Lamb Growth ◽  
Pregnant Mare Serum Gonadotrophin ◽  
Restricted Feed Intake

The interactions between two planes of pre- and post-natal nutrition of grazing ewes and the level of fertility on: ( a ) birth weight of the lamb, ( b ) its subsequent growth rate, and ( c ) wool growth, were determined in 140 crossbred ewes (52 Romney Marsh X Merino, 88 Border Leicester X Merino). The effectiveness of pregnant mare serum gonadotrophin (PMS) , injected on the 12th to 14th day of the oestrous cycle, for raising fertility ' was also investigated. Romney cross ewes had commenced their breeding season before January 21, a t least 3 weeks earlier than Border Leicester cross ewes. They lambed correspondingly earlier. The overall lambing percentage was very high (139 per cent.). PMS had no significant effect. There was no breed difference. Low- and high-plane ewes gained an average of 20 and 54 lb respectively during pregnancy. The mean weight of the conceptus was 34 lb (twins 39 Ib, singles 25 lb). Hence low-plane ewes lost an average of 14 lb body tissue as compared with a gain of 20 lb by high-plane ewes. Mean birth weights of lambs - single and multiple pregnancies - from the two nutritional groups were indistinguishable. Lamb losses and lambing troubles were fewer in the low--plane group. There was no interaction of pre- and post-natal nutrition on subsequent lamb growth rate. Post-natal plane of nutrition, sex of the lamb, and number reared all had highly significant effects on lamb growth rate. There were also significant interactions between plane of nutrition of the ewe and number of lambs reared and sex of lambs. Wether lambs needed the best possible nutritional environment fully to exhibit their inherent superior growth rate over ewe lambs. Restricted feed intake either in pregnancy or in lactation reduced wool growth to approximately the same degree. Although birth and weaning weights were affected by the number of lambs born and reared, wool production of the dam was not affected.

Comparisons of the productivity of sheep grazing natural pastures of the Riverine Plain

1970 ◽  
Vol 10 (46) ◽  
pp. 549 ◽  
Author(s):  
AD Wilson ◽  
JH Leigh
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Late Summer ◽  
Summer Rainfall ◽  
High Growth Rate ◽  
First Year ◽  
Sheep Grazing ◽  
Wool Growth ◽  
The Mean ◽  
Second Year

The productivity of Merino sheep grazing on the semi-arid natural shrub (Atriplex vesicaria) and grassland (Danthonia caespitosa-Stipa variabilis, D. caespitosa, S. variabilis) pastures of the Riverine Plain was measured over three years. At 0.5 sheep to an acre, the sheep on A. vesicaria (bladder saltbush) community at first grew more wool than those on the grasslands, but wool growth rate declined in autumn to the same degree as on the grassland. In the second year most of the A. vesicaria bushes did not recover from grazing and wool growth-rate fell to half that on the grasslands. The sheep on A. vesicaria had to be removed in the second year, but on the grasslands there was no evidence that sheep could not be maintained indefinitely at that stocking rate. At 1.0 sheep to an acre, both the A. vesicaria and the D. caespitosa-S. variabilis grassland were incapable of maintaining the sheep for the duration of the experiment. Wool growth of the sheep on the grasslands showed an annual rhythm, with high growth-rate in spring (14 g per day) followed by a gradual decline in rate to 6-8 g per day in late summer and autumn. However, the extent of this decline was dependent on summer rainfall, as in one summer when rainfall was high, wool growth-rate was maintained at near the spring rate. The mean annual rate of wool growth was found to be correlated (r = + 0.92, P<0.01) to summer rainfall (November-April). The weight gain of weaner sheep was best on E. caespitosa, and was equaiied by that on A. vesicara only in the first year. Growth was not influenced by the presence or absence of bushes of Kochia aphylla Growth on S. variabilis was less than on D. caespitosa.

scholarly journals The role of reproductive loss on flock performance – a comparison of nine industry flocks

2021 ◽  
Author(s):  
Paul R Shorten ◽  
Sara J Edwards ◽  
Jenny L Juengel
Keyword(s):  
Growth Rate ◽  
Reproductive Performance ◽  
Survival Probability ◽  
Ovulation Rate ◽  
Embryo Survival ◽  
Ewe Lambs ◽  
Reproductive Loss ◽  
Lamb Survival ◽  
Lamb Growth

Abstract The reproductive performance of a sheep flock is dependent on a multitude of complex interacting factors. Attaining optimal flock performance requires information about how the reproductive steps are linked and relate to readily available measurements of the state of the flock. The goal was to use data from nine commercial flocks (greater than 300,000 records) to investigate and model the key reproductive steps affecting flock reproductive performance. We also developed a maximum-likelihood based methodology to predict flock ovulation rate based on measurements of the number of fetuses at mid-pregnancy (detected by ultrasound-scanning). The model was used to determine how changes in pre-mating liveweight, age, predicted ovulation rate, number of fetuses at mid-pregnancy, lamb survival and lamb growth rate affect the total lamb liveweight at weaning per ewe exposed to the ram in each flock. The data from the commercial flocks were also used to investigate the role of ewe age and pre-mating liveweight on each reproductive step. Sensitivity analyses were conducted to identify the key reproductive steps affecting flock reproductive performance, with a focus on understanding how these steps vary between flocks. The elasticity for embryo survival was 60% of that for lamb survival for these flocks and the elasticities for ovulation rate were highly variable between flocks (0.16 − 0.50 for mature ewes). This indicates that ovulation rate was near-optimal for some flocks, whereas there was potential to significantly improve flock performance in suboptimal flocks. The elasticity for ewe pre-mating liveweight was highly variable between flocks (-0.03 to 0.84 for mature ewes and -0.18 to 1.39 for ewe lambs), indicating that pre-mating liveweight ranged from optimal to suboptimal between flocks. For these suboptimal farms, opportunity exists to increase flock performance through improved management of ewe pre-mating liveweight. Reproductive loss was significantly greater in ewe lambs than mature ewes, although the difference is dependent on the stage of reproduction and flock. Predicted ovulation rate was 25% lower for ewe lambs and there was a 30% relative decrease in the predicted embryo survival probability from ovulation to scanning for ewe lambs. There was a 10% relative decrease in lamb survival probability from birth to weaning for ewe lambs and lamb growth rate was 25% lower for ewe lambs.

Effect of premating shearing on reproductive performance in ewe lambs after oestrus synchronization

1991 ◽  
Vol 116 (1) ◽  
pp. 135-138
Author(s):  
J. V. O'Doherty ◽  
T. F. Crosby
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Reproductive Performance ◽  
Medroxyprogesterone Acetate ◽  
Conception Rate ◽  
Factorial Experiment ◽  
Ewe Lambs ◽  
Significant Difference ◽  
Lamb Growth

SUMMARYOne hundred and fifty-four, March-born, lowland ewe lambs, on the Lyons Estate farm, were allocated to a 2×2 factorial experiment. In September 1987, half were shorn and 1 month later the lambs were treated with intravaginal sponges, containing either 60 mg medroxyprogesterone acetate or 40 mg fluorogestone acetate, for 12 days. Following sponge removal, ewes were mated to fertile rams at a ram: ewe ratio of 1:6. There was no significant difference in reproductive performance between the two progestagen treatments (P > 0·05). Premating shearing increased (P < 0·01) conception rate and reduced the percentage of barren ewes (P < 0·01) but there was no effect on litter size. Time of gestation following shearing was increased (P < 0·01) by 1·24 days. Lamb growth rate up to weaning was not affected by the shearing treatment. The results of this trial indicate positive advantages of premating shearing of ewe lambs.

Attainment of puberty and reproductive performance in Clun Forest ewe lambs

1972 ◽  
Vol 78 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Ó. R. Dýrmundsson ◽  
J. L. Lees
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Breeding Season ◽  
Reproductive Performance ◽  
First Year ◽  
Cyclic Activity ◽  
Breeding Activity ◽  
Ewe Lambs ◽  
Wide Range ◽  
The Mean

SUMMARYCertain aspects of puberal development and reproductive performance in Clun Forest ewe lambs with a wide range of birth dates were investigated during the two seasons 1969–71. Of 33 ewe lambs born in the spring of 1969, 26 exhibited their first oestrus at a mean date of 8 November 1969 ± 2·5 days, the mean age being 228·3 ± 2·4 days and the mean body weight 36·3 ± 0·9 kg. The lambs which failed to breed in their first year, together with lambs born in the autumn of 1969, attained puberty during the autumn of 1970. Twenty-three ewe lambs carried foetuses to term in the spring of 1970 and had a mean lambing rate of 113·0 ± 7%. Of 84 ewe lambs born in the spring of 1970, 73 attained puberty in the first year of life at a mean date of 11 November 1970 ± 2·7 days, the mean age being 223·7 ± 3·0 days and the mean body weight 32·2 ± 0·5 kg. Cyclic activity of ewe lambs born in 1970 was recorded throughout their first breeding season. They experienced their last oestrus of the season at a mean date of 24 January 1971 ± 2·2 days, the mean age being 296·9 ±3·9 days and the mean body weight 32·4 ± 0·6 kg. The mid-breeding season was 18 December 1970, coinciding with the shortest days, and the mean number of heats exhibited throughout the season was 5·15 ± 0·24 per lamb.Marked individual variation existed in age and body weight at puberty and in breeding activity, largely due to differences in date of birth and growth rate during rearing. Ewe lambs born early tended to experience their first oestrus earlier in the season than late born lambs but they did so at a higher age and heavier body weight. Fast growth rate and earliness of puberty were associated with extended duration and enhanced regularity of cyclic activity. Time of birth was clearly of fundamental importance in relation to the onset and duration of breeding activity in the ewe lambs included in the present study.Adult rams of three breeds were found to vary consistently in the proportion of ewe lambs which they detected in oestrus, rams of the lambs' own breed being most efficient.

The incidence of central serous chorioretinopathy in the population of Kazan: Results of a retrospective epidemiological analysis for 2009–2018

2020 ◽  
pp. 30-33
Author(s):  
D. R. Аgliullin ◽  
G. R. Khasanova ◽  
E. A. Abdulaeva ◽  
S. T. Agliullina ◽  
A. N. Amirov ◽  
...  
Keyword(s):  
Growth Rate ◽  
Central Serous Chorioretinopathy ◽  
Morbidity Rate ◽  
Seasonal Prevalence ◽  
Upward Trend ◽  
Epidemiological Analysis ◽  
Significant Upward Trend ◽  
Track Record ◽  
Minimum Age ◽  
The Mean

Objective: To assess the incidence of central serous chorioretinopathy (CSC) through the example of a large industrial Russian city.Methods: A retrospective analysis of CSC of Kazan population for 2009–2018 has been done.Results: From 2019 to 2018, 831 new cases of CSC were registered in Kazan. A statistically significant upward trend with growth rate 105.2% and accession rate 5.2% was typical for the annual track record. The mean age of patients was 50 years, the minimum age was 14 years, the maximum age was 87 years. A statistically significant upward trend was detected in track record of incidence in groups of 30–39-year-old and 40–49-year-old. Seasonal increase of the incidence was recorded in February, March, April, October, and November.Conclusions: The upward trend and seasonal prevalence are typical for longterm morbidity of CSC in Kazan. The highest morbidity rate of CSC and statistically significant upward trend of its incidence in track record were recorded in the age of 30–39. 

Continuous Precipitation of Lead Iodide

1994 ◽  
Vol 59 (7) ◽  
pp. 1503-1510
Author(s):  
Stanislav Žáček ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Crystal Size ◽  
Crystal Growth Rate ◽  
Laboratory Model ◽  
Lead Iodide ◽  
Secondary Nucleation ◽  
Equimolar Ratio ◽  
Continuous Precipitation ◽  
The Mean

Lead iodide was precipitated from aqueous solutions of 0.015 - 0.1 M Pb(NO3)2 and 0.03 - 0.2 M KI in the equimolar ratio using a laboratory model of a stirred continuous crystallizer at 22 °C. After reaching the steady state, the PbI2 crystal size distribution was measured sedimentometrically and the crystallization kinetics was evaluated based on the mean particle size. Both the linear crystal growth rate and the nucleation rate depend on the specific output of the crystallizer. The system crystallization constant either points to a significant effect of secondary nucleation by the mechanism of contact of the crystals with the stirrer blade, or depends on the concentrations of the components added due to the micromixing mechanism.

scholarly journals Mammary Gland Structures Are Not Affected by an Increased Growth Rate of Yearling Ewes Post-Weaning but Are Associated with Growth Rates of Singletons

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 884
Author(s):  
Emmanuelle Haslin ◽  
Rene A. Corner-Thomas ◽  
Paul R. Kenyon ◽  
Adrian J. Molenaar ◽  
Stephen T. Morris ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mammary Gland ◽  
Live Weight ◽  
Late Pregnancy ◽  
Control Group ◽  
Early Lactation ◽  
Fat Pad ◽  
Negative Effects ◽  
Lamb Growth ◽  
Heavy Group

The experiment aimed to examine the impacts of an increased growth rate of ewes between three and seven months of age on udder development using ultrasound and to establish whether ultrasonography could be used to identify ewe mammary structures that may be indirect indicators of singleton growth to weaning. Udder dimensions, depths of gland cistern (GC), parenchyma (PAR) and fat pad (FP) were measured in late pregnancy (P107), early lactation (L29), and at weaning (L100) in 59 single-bearing yearling ewes selected from two treatments. The ‘heavy’ group (n = 31) was preferentially fed prior to breeding achieving an average breeding live-weight of 47.9 ± 0.38 kg at seven months of age. The ‘control’ group (n = 28) had an average breeding live-weight of 44.9 ± 0.49 kg. Udder dimensions, GC, PAR and FP did not differ between treatments. Lamb growth to L100 was positively associated (p < 0.05) with PAR at P107 and GC at L29. There was no evidence of negative effects of the live-weight gain treatments on udder development of yearling ewes as measured by ultrasonography. The results suggest that this ultrasound method has the potential to identify pregnant yearling ewes which would wean heavier singletons.

Seasonal variations in wool growth and heat tolerance of sheep. I. Wool growth

1960 ◽  
Vol 11 (1) ◽  
pp. 75 ◽  
Author(s):  
M Wodzicka
Keyword(s):  
Body Weight ◽  
Day Treatment ◽  
The Other ◽  
Seasonal Rhythm ◽  
Group Iii ◽  
Wool Growth ◽  
Group I ◽  
The Mean ◽  
Group Ii ◽  
The Difference

The monthly wool growth of three groups of rams was studied at Beltsville, Maryland. Group I received natural daylight (at 38° 53' N.) and was shorn monthly. Group II had a 7:17 hours of daylight to hours of darkness rhythm and was shorn every 6 months, once in winter and once in summer. Group III received natural daylight and was likewise shorn every 6 months. The rams of all groups produced more wool in summer than in winter. This difference was significant (P<0.001). The mean body weight and food intake were both greater in the winter months, which indicated that the seasonal rhythm of wool growth was not a consequence of poorer feeding in winter. The rams which were shorn monthly (group I) grew considerably more wool than the other two groups, but the difference was not statistically significant. The short-day treatment of group II did not increase the annual wool production nor decrease the seasonal rhythm of wool growth. The balance of evidence from this and other experiments indicates that temperature rather than light controls the seasonal rhythm of wool growth.

Effects of lasalocid and protein levels on feed intake and growth rate of Awassi lambs

1997 ◽  
Vol 1997 ◽  
pp. 187-187
Author(s):  
M. M. Muwalla ◽  
M. Y. Harb ◽  
T. F. Crosby
Keyword(s):  
Growth Rate ◽  
Feed Intake ◽  
Feed Efficiency ◽  
Published Data ◽  
Growth Promoter ◽  
Feed Conversion ◽  
Protein Levels ◽  
Feedlot Lambs ◽  
Lamb Growth ◽  
Awassi Lambs

Lasalocid is a polyether antibiotic derived from the fermentation of streptomyces lasaliensis used as a coccidiostat in sheep. There are varying literature reports on lamb growth rate and feed intake when lasalocid is included in the diet of feedlot lambs. While some reports have shown that lasalocid enhances feed efficiency in ruminants by decreasing feed intake and either maintaining or improving rate of gain others indicate that lasalocid did not have any effect on lamb growth rates or feed efficiency (Stobart et al., 1987). Also, when lasalocid was fed to Chios lambs, growth rate was increased but there was no improvement in feed conversion efficiency (Hadjipanayiotou et al., 1988). There are no published data in the literature relating to the use of lasalocid as a growth promoter in the Awassi breed of sheep fed complete diets and the purpose of this study was to investigate the effect of lasalocid with two levels of protein on the growth rate and feed efficiency of weaned male and female Awassi lambs.

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