Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 2. Reproductive performance

1984 ◽  
Vol 24 (124) ◽  
pp. 47 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Reproductive Performance ◽  
Early Life ◽  
Unit Area ◽  
Adult Life ◽  
Stocking Rate ◽  
Area Basis ◽  
Lamb Survival ◽  
Stocking Rates

The reproductive performance of ewes subjected to four nutritional regimes from conception to 15 months of age was recorded from first lambing at 24 months until the seventh lambing. The ewes were grazed at 10 and 20 sheep/ha. The proportion of ewes which exhibited oestrus at their first mating was less in those which had grazed at a high stocking rate between 3 and 15 months, and fecundity was increased by 15% in subsequent years by a high plane of nutrition between conception and 3 months of age, but only when ewes were grazed at a low stocking rate as adults. Ewes stocked at 10 sheep/ha weaned 50% more lambs than ewes stocked at 20 sheep/ha in adult life, but the more heavily stocked ewes weaned approximately 33% more lambs on a unit area basis. Approximately half the variability in the number of lambs weaned per ewe available for service was associated with variability in lamb survival. Relationships between the proportion of ewes showing oestrus, fecundity, survival of lambs, overall reproductive performance and liveweight of ewes are presented.

Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 3. Survival of ewes and their lambs, and the implications for flock productivity

1984 ◽  
Vol 24 (124) ◽  
pp. 57 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Computer Model ◽  
Early Life ◽  
Adult Life ◽  
Stocking Rate ◽  
Cumulative Mortality ◽  
Severe Wear ◽  
Wool Production ◽  
Stocking Rates

A stocking rate of 20 sheep/ha in adult life was associated with greater mortality of ewes and their lambs than a stocking rate of 10 sheep/ha, but mortality was not affected by the nutrition of the ewes in early life. Survival of lambs born as twins to weaning was 42% at the high stocking rate and 72% at the low. Corresponding values for singletons were 73 and 87%. Differences in survival of singleton but not twin lambs were established during the first 5 d of life. Mortality of ewes was greater at a high stocking rate and by nine years of age approximately twice the number of ewes had died at the high as at the low stocking rate. Incisor wear and losses were greater in sheep stocked as adults at the high stocking rate, and within this flock was more marked in ewes reared at a low than in those reared at a high stocking rate. Severe wear and loss of incisor teeth were not correlated with cumulative mortality at 108 months. Data reported in this and in the two previous papers in this series were synthesized into a computer model which was used to predict wool production and the numbers of lambs and surplus ewes available for sale when culling age was varied from four to eight years. Wool production and the numbers of surplus sheep available for sale were predicted to be greater at the higher stocking rate with the exception of the number of surplus female lambs available from flocks in which their mothers were culled at six years or earlier.

The design and interpretation of experiments to study animal production from grazed pasture

1968 ◽  
Vol 71 (3) ◽  
pp. 327-335 ◽  
Author(s):  
J. B. Owen ◽  
W. J. Ridgman
Keyword(s):  
Simple Model ◽  
Unit Area ◽  
Personal Communication ◽  
Animal Production ◽  
Stocking Rate ◽  
Grazed Pasture ◽  
Stocking Rates ◽  
Pasture Productivity

SUMMARYExperiments designed to assess differences between treatments in pasture productivity as measured by the production of animals are complicated by the stocking rates chosen. The paper attempts toderive a simple model relating production per animal and production per unit area to stocking rate for meat animals, based on biological considerations.A method is proposed which would allow meaningful grazing experiments to be carried out employing only one stocking rate, thus considerably reducing the expense of this type of experimentation.The model is applied to some recent data obtained by Hodgson (1966) and Appleton (1967, personal communication).

scholarly journals Herbage Mass Productivity and Carrying Capacity Estimation of Some of the Selected Rangelands of Taplejung District

1970 ◽  
Vol 11 ◽  
pp. 63-70
Author(s):  
NR Devkota ◽  
MR Kolachhapati
Keyword(s):  
Carrying Capacity ◽  
Unit Area ◽  
Growth Period ◽  
Grazing Management ◽  
Optimum Number ◽  
Specific Information ◽  
Mass Yield ◽  
Stocking Rate ◽  
Site Specific ◽  
Stocking Rates

A study of the representing rangelands of Taplejung district was carried out during summer of 2009 to estimate the herbage mass yield of different slope categories, and to calculate the carrying capacity (CC) of the representing rangelands based on 60 days re-growth period so that optimum number of livestock unit (LU) per unit area would be possible to allow for grazing. The findings revealed that plain slope had higher herbage mass produced, but was comparatively over-grazed as revealed by higher stocking rate. Existing carrying capacity reasonably supports the grazers, but irrespective of the quality herbage. In deed there was a lower CC for higher slope area with higher CC for plain slope. Nevertheless, the CC values for different slope categories indicated that rangelands in Taplejung district has wider scope of improvement, both for herbage mass productivity, and grazing management through precise stocking rates to match with the prevailing carrying capacity. A major challenge, however, lies to convince herders about the benefits of reducing stocking rates and improving production efficiencies, with the increased income and less degradation of the present available rangelands. Detail study on herbage mass production based on total herbage mass harvest days of a year along with stocking rate for the respective period would be important to consider in generating concrete and site specific information. Key words: herbage mass; carrying capacity; stocking rate; rangelands; herders; Taplejung district DOI: 10.3126/njst.v11i0.4125Nepal Journal of Science and Technology 11 (2010) 63-70

Decreasing the mob size but not stocking rate of ewes at lambing increases the survival of twin lambs born on farms across southern Australia

2020 ◽  
Vol 60 (16) ◽  
pp. 1949 ◽  
Author(s):  
A. Lockwood ◽  
J. Trompf ◽  
L. Kubeil ◽  
A. Thompson ◽  
G. Refshauge ◽  
...  
Keyword(s):  
Resource Allocation ◽  
Stocking Rate ◽  
South Eastern ◽  
Factorial Combination ◽  
Eastern Australia ◽  
Context Data ◽  
Lamb Survival ◽  
On Farm ◽  
Stocking Rates ◽  
South Eastern Australia

Context Data collected from producers in south-eastern Australia found that the survival of twin-born lambs decreased by 3.5% for each extra 100 ewes in the mob at lambing. Increasing stocking rate by 1 ewe/ha decreased lamb survival by a further 0.7%. These survey findings suggest that lamb survival could be improved by optimising the allocation of ewes to mobs and paddocks at lambing. Aim The present paper reports two experiments. Experiment 1 tested the hypotheses that (1) the survival of twin-born lambs would be greater when ewes lamb in smaller mobs and at lower stocking rates, and (2) the effects of mob size and stocking rate would be greater in Merinos than in non-Merino breeds. Experiment 2 tested the hypothesis that the survival of twin-born Merino lambs would be greater at lower mob sizes when ewes lambed at stocking rates <4 ewes/ha. Methods Experiment 1 investigated a 2 × 2 factorial combination of mob size (high or low) and stocking rate (high or low) on the survival of twin-born Merino and non-Merino lambs at 70 on-farm research sites across southern Australia. Experiment 2 investigated the effect of high or low mob size on the survival of twin-born Merino lambs when ewes lambed at stocking rates of <4 twin ewes/ha at 15 on-farm research sites. In both experiments, adult twin-bearing ewes were randomly allocated into a treatment and lambing paddock on Day 140 from the start of joining at each farm. Lamb survival in each mob was calculated based on lamb losses between pregnancy scanning and lamb marking. Key results In both experiments, the effect of mob size on lamb survival was found to be linear, with survival of twin-born lambs decreasing by between 1.9% and 2.5% per additional 100 ewes in the mob at lambing, regardless of breed (P < 0.001). In Experiment 1, there was no effect of stocking rate or mob size by stocking rate on lamb survival. Conclusions The present research demonstrated that reducing mob size but not stocking rate will improve the survival of twin-born lambs to marking for extensive enterprises in Australia where ewes lamb at stocking rates of up to 12 ewes/ha. Implications These findings will contribute to guidelines for optimising ewe nutrition and resource allocation to improve lamb survival.

Environmental and genetic factors influence the liveweight of adult Merino and Border Leicester × Merino ewes across multiple sites and years

2016 ◽  
Vol 56 (4) ◽  
pp. 775 ◽  
Author(s):  
S. E. Blumer ◽  
G. E. Gardner ◽  
M. B. Ferguson ◽  
A. N. Thompson
Keyword(s):  
Reproductive Performance ◽  
Genetic Factors ◽  
Supplementary Feeding ◽  
Stocking Rate ◽  
Breeding Values ◽  
Management Interventions ◽  
Factors Influencing ◽  
Farm Profitability ◽  
Lamb Survival ◽  
Poor Nutrition

Variation in liveweight change in the ewe flock during periods of poor nutrition can affect farm profitability through the effects of liveweight loss on potential stocking rate, management interventions including supplementary feeding, and ewe and lamb survival and productivity. There is variation between individual animals in their ability to manage periods of poor nutrition, but the links between liveweight change and breeding values in the adult ewe flock have not been quantified. We analysed 5216 liveweight profiles for 2772 ewes managed over 3 years at eight sites across Australia, to define the relative effects of environment, reproductive performance and breeding values on liveweight change. The range in liveweight loss varied from 1.3 kg to 21.6 kg, and for liveweight gain from 0.4 kg to 28.1 kg. Site and year had the largest influence on liveweight change, which demonstrates that seasonal conditions and management were the most important factors influencing liveweight change. Liveweight loss was influenced by previous and current reproductive performance but these effects were small in comparison to the effects of site and year. There were mixed associations with sire breeding values for growth, fat and muscle depending on site. An increase in sire breeding values for fat by 1 mm was associated with a reduction in liveweight loss by up to 1.3 kg regardless of ewe breed, and this was more evident at sites where ewes lost a greater proportion of their liveweight. While management had the greatest effect on liveweight change, there appears to be scope to use breeding values to select sheep that will lose less weight during periods of poor nutrition in some environments.

Performance of sheep systems grazing perennial pastures. 3. Fertility, fecundity and lamb survival

2020 ◽  
Vol 60 (3) ◽  
pp. 414
Author(s):  
Susan M. Robertson ◽  
Michael A. Friend
Keyword(s):  
Reproductive Performance ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Reproductive Output ◽  
The Other ◽  
Management Systems ◽  
Stocking Rate ◽  
Farm Profit ◽  
Lamb Survival ◽  
In Pregnancy

Management system has the potential to alter the reproductive output of sheep flocks and thereby farm profit. A study was conducted between 2006 and 2010 to evaluate the reproductive performance of four management systems with differing combinations of time of lambing, stocking rate and ram breed, while grazing at a similar midwinter stocking rate (dry-sheep equivalents per hectare of 8, 10.2, 13, 11.2 and 11.2 in the successive seasons 2006–2010). Three systems, winter lambing Merino (WLM), split lambing (SL) and later lambing (LL), grazed replicated farmlets comprising pastures that were 20% lucerne (Medicago sativa), 20% tall fescue (Festuca arundinacea) and 60% phalaris (Phalaris aquatica). A fourth system (high lucerne (HL)) grazed farmlets of 40% lucerne, 15% tall fescue and 45% phalaris. All systems used Merino ewes: in WLM mated to Merino rams, lambing in July; in SL half of the ewes lambing to terminal-breed rams in July, the other half lambing to Merino rams in September; and in LL and HL lambed in September, half to terminal-breed and half to Merino rams. The number of lambs weaned per ewe joined was 10% higher (P < 0.05) in the WLM system (0.99 ± 0.03) than in the September-lambing systems LL and HL, largely a result of a higher number of fetuses per ewe and despite lower (P < 0.05) lamb survival to marking in some years. The SL system weaned a similar (P > 0.05) number of lambs per ewe (0.95 ± 0.03) to all other systems. However, the number of lambs weaned per hectare was least in WLM (4.6 ± 0.2), lower than in the HL and LL systems by 2.7 lambs/ha because of a lower stocking rate. The ranking of systems for fetal number and lamb survival was not consistent among years. Spring-lambing systems produced more lambs per hectare because of a higher stocking rate but fewer lambs per ewe than the WLM system. System differences in pregnancy rate, fecundity and lamb survival were not consistent between years.

The survival of lambs in shelter declines at high stocking intensities

2012 ◽  
Vol 52 (7) ◽  
pp. 497 ◽  
Author(s):  
S. M. Robertson ◽  
B. J. King ◽  
J. C. Broster ◽  
M. A. Friend
Keyword(s):  
Block Design ◽  
Stocking Rate ◽  
Nutritional Conditions ◽  
Lamb Survival ◽  
Stocking Rates

This experiment evaluated the effect of stocking intensity at lambing on lamb survival. A randomised block design with three replicates compared stocking rates of 16 and 30 ewes/ha. Twin-bearing Merino ewes (n = 69) that had been mated with Poll Dorset × White Suffolk rams were placed in paddocks sheltered with rows of hessian, with 8 or 15 ewes per 0.5-ha plot for the low and high stocking rates, respectively. The survival of lambs born alive at the high stocking rate (63%) was 24% less (P = 0.002) than for those at the low stocking rate (83%), and was associated with a higher (P < 0.05) proportion of lambs dying from starvation, mismothering or exposure. There were no differences (P > 0.05) in lamb birthweight, marking weight, ewe liveweight or condition, suggesting nutritional conditions between the stocking rates were similar. The results suggest caution in using lambing strategies which require high stocking rates.

Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 1. Wool production and quality, lamb growth rate, and size and liveweight of ewes

1984 ◽  
Vol 24 (124) ◽  
pp. 34 ◽  
Author(s):  
JP Langlands ◽  
GE Donald ◽  
DR Paull
Keyword(s):  
Fibre Diameter ◽  
Adult Life ◽  
Stocking Rate ◽  
Wool Production ◽  
Ewe Lambs ◽  
Subjective Assessments ◽  
Early Adult Life ◽  
Treatment Trends ◽  
Stocking Rates ◽  
Lamb Growth

Ewe lambs born to Merino ewes grazed at 10 or 20 sheep/ha were weaned at three months (L-, H-) and randomized to low or high stocking rate treatments (-L, -H) until 15 months old. Ewes from each of the four groups (LL, LH, HL and HH) then grazed at 10 or 20 sheep/ha until nine years old. Liveweight in early adult life and some body dimensions were reduced by a low plane of nutrition during rearing. The differences in liveweight declined with time and were not significant after 2% years in ewes stocked as adults at 10/ha or after 5% years in ewes stocked at 20/ha. Wool production and growth rates of lambs were reduced when ewes were stocked at the high stocking rate, but were not affected by rearing treatment. Wool production per sheep was about 30% greater at the lower stocking rate but about 33% less when expressed on a unit area basis. Fibre diameter and fleece length were reduced by a high stocking rate in adult life but were not affected by rearing treatment. Yield was not affected by stocking rate at any time. A number of subjective assessments of wool quality were also recorded; quality declined at a high stocking rate but was not affected by rearing treatment. Trends in wool production and quality with age of ewe are reported.

The effect of feeding supplements in the autumn on the reproductive performance of grazing ewes 1. Feeding fixed amounts of supplement before and during mating

1992 ◽  
Vol 54 (2) ◽  
pp. 243-248 ◽  
Author(s):  
R. G. Gunn ◽  
J. A. Milne ◽  
A. J. Senior ◽  
A. M. Sibbald
Keyword(s):  
Organic Matter ◽  
Body Condition ◽  
Reproductive Performance ◽  
Fish Meal ◽  
Live Weight ◽  
Stocking Rate ◽  
Mating Period ◽  
Sward Height ◽  
Stocking Rates ◽  
Effect Of Feeding

AbstractThe effects on reproductive performance offeeding supplements to ewes grazing predominantly perennial ryegrass swards before and during mating which started in mid November were examined with approximately 200 Scottish Blackface ewes in each of three experiments. In two experiments, ewes were offered no supplement (C), 600 g barley (S(B)) or 500 g barley + 100 g white-fish meal (S(B + FM)) per head per day from 3 weeks before until 3 weeks after the start of the mating period. Ewes in experiment 1 were grazed on different areas and in experiment 2 were rotated around these areas on a 12-day cycle. Initial herbage allowance in both experiments was 40 to 50 kg organic matter per ewe and stocking rates ranged from 10 to 14 ewes per ha. Ewes in experiment 3 were rotated around the same areas on a 10-day cycle at a stocking rate of 18 ewes per ha and offered either no supplement (C) or 600 g barley (S(B)) per head per day when live weight started to decrease or sward height declined to 3·5 cm, whichever occurred first. Both of these occurred shortly after the start of mating. Sward height fell from mid October and throughout November and was between 3 and 4 cm at the start of mating in all experiments.There were no differences in response to the (S(B)) and (S(B + FM)) treatments in live weight, body condition or reproductive performance in experiments 1 and 2 and the effects of supplementation were examined with these treatments pooled.Supplementation had very little effect on live weight, resulting in higher values only in experiment 1 but did produce higher body condition in all experiments. This occurred by the start of mating in experiment 1 but not until mid December in experiment 3 and early January in experiment 2.A significant increase in the number of lambs born per ewe lambing was obtained from supplementation when the data from experiments 1 and 2 were combined (P < 0·05). There was no response in reproductive performance to supplementation in experiment 3. It was concluded that supplementation in the pre-mating period can improve reproductive performance when sward height declines from 6 to 3·5 cm but that supplementation in the post-mating period may not, even when the sward height is below 3·5 cm.

Some comments on the shape of the gain–stocking rate curve

1976 ◽  
Vol 86 (1) ◽  
pp. 103-109 ◽  
Author(s):  
J. Connolly
Keyword(s):  
Unit Area ◽  
Rate Curve ◽  
Stocking Rate ◽  
Optimum Rate ◽  
Rate Relationship ◽  
Stocking Rates ◽  
True Relationship ◽  
Selection Of

SUMMARYIn this paper the method proposed by Jones & Sandland (1974) for testing the linearity of the animal gain–stocking rate relationship is examined. It is shown that the method cannot be used to establish such linearity. An examination of the biases in estimation of optimum stocking rate and gain per animal and per unit area at the optimum stocking rate arising out of assuming linearity where the true relationship was quadratic led to the following conclusions. Quite large biases can arise. Selection of stocking rates straddling the true optimum reduces these biases. If experimental stocking rates are lower than the true optimum stocking rate the optimum stocking rate is overestimated and the animal gain at optimum is underestimated and vice versa if the experimental stocking rates exceed the true optimum rate.

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