scholarly journals Maximising lamb growth rate - just what is possible in a high performance system

2003 ◽  
pp. 61-63 ◽  
Author(s):  
P.D. Muir ◽  
N.B. Smith ◽  
J.C. Lane
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
High Performance ◽  
Breeding Value ◽  
Average Weight ◽  
Average Growth Rate ◽  
Experimental Conditions ◽  
Average Growth ◽  
Performance System ◽  
Lamb Growth

Abstract This study set out to demonstrate what could be achieved in terms of lamb growth rates under controlled experimental conditions. Ewes with high breeding values for progeny growth rate were selected from within a flock of 900 ewes and mated using AI to a ram with a high breeding value for progeny growth rate. Of the 70 ewes mated, 44 reared 75 lambs (170%) to 12 weeks of age. Lamb birth weights averaged 4.8 kg. Ewes and lambs were fed on pasture covers between 1800 and 2600 kg DM/ha throughout lactation. At 12 weeks of age, the average weight of all lambs in the mob averaged 39 kg. Average growth rate of all lambs from birth to 12 weeks was 409 g/d, with single, twin and triplet lambs averaging 437, 407 and 380 g/d respectively. The best individual lamb grew at 549 g/d and weighed 51.6 kg at 12 weeks. This demonstration sets a new benchmark for both mob and individual lamb growth rates and indicates what can be achieved with a combination of genetics for growth, ewes with good milking ability and good pasture feeding conditions. Keywords: breeding value, lamb growth rate, milking ability, pasture quality

Growth and carcass characteristics of crossbred lambs in various production systems

2012 ◽  
Vol 52 (5) ◽  
pp. 373 ◽  
Author(s):  
N. M. Fogarty ◽  
J. G. Mulholland
Keyword(s):  
Growth Rate ◽  
Production Systems ◽  
Growth Traits ◽  
Carcass Weight ◽  
Wagga Wagga ◽  
Hybrid Vigour ◽  
Average Growth Rate ◽  
Lower Growth ◽  
Average Growth ◽  
Lamb Growth

Lamb growth, carcass and pelt measurements are reported from 5775 lambs born to Border Leicester × Merino (BLM) and Hyfer (Dorset × Merino composite) ewes joined to Dorset, Suffolk and Hyfer rams in three lamb-production systems at Cowra and Wagga Wagga over 5 years. The production systems involved lambings at different seasons of the year and increasing levels of intensification from autumn annual joining, spring joining with a backup mating for non-pregnant ewes, to an accelerated 8-monthly lambing system. Lambs from BLM ewes were 0.7 kg heavier at birth and grew 3% faster and reached slaughter, at 18 kg carcass weight, 1–2 weeks earlier than did lambs from Hyfer ewes (P < 0.01). The advantage in growth rate of lambs from BLM compared with Hyfer ewes was greater for lambs born in November. These lambs had poorer growing conditions over the summer months, with 22% lower growth rate and taking 5 weeks longer to reach slaughter than did lambs born in March or August. There was no difference between Dorset and Suffolk sire breeds for any lamb growth traits, with lambs from Hyfer sires growing 7% slower. Ram and cryptorchid lambs reached slaughter 1 week earlier than did wethers, with ewes a further 9 days later (P < 0.01). Sex differences were maximised when lamb growth was greatest. There were no differences in carcass fat measurements between ram and cryptorchid lambs, although both were considerably leaner than wethers (2.2–3.0 mm fat at the GR site), which were 1.3–2.1 mm leaner than ewes at 18-kg carcass weight. The range in average growth rate of progeny of the BLM ewes from the 12 different source flocks at Cowra and Wagga Wagga was 10–14% of the mean which was twice the difference in average growth rate of progeny from the BLM and Hyfer dams. There was also significant variation among the BLM source flocks for carcass fat measurements. Lamb progeny from the different sire- and dam-breed combinations had varying levels of heterozygosity. There appears to be little loss of heterosis or hybrid vigour for lamb growth, although the sire breed × dam breed interaction was significant (P < 0.01) for age at slaughter at Wagga Wagga, in which the ranking of the lamb types was consistent with the levels of heterozygosity. The estimates of between-lambing repeatability for the ewes were highest for birthweight (0.35 Cowra and 0.27 Wagga Wagga) and declined at later ages (0.26–0.17), with lower estimates for carcass traits.

scholarly journals Assessing the lockdown effect from excess mortalities

2021 ◽  
Author(s):  
Alexej Weber
Keyword(s):  
Growth Rate ◽  
South Korea ◽  
Growth Rates ◽  
Excess Mortality ◽  
Reproduction Number ◽  
Average Growth Rate ◽  
Average Growth ◽  
Reproduction Numbers ◽  
The Difference ◽  
Pharmaceutical Interventions

AbstractBackground and AimsThe reported case numbers of COVID-19 are often used to estimate the reproduction number or the growth rate. We use the excess mortality instead, showing the difference between most restrictive non-pharmaceutical interventions (mrNPIs) and less restrictive NPIs (lrNPIs) with respect to the growth rate and death counts.MethodsWe estimate the COVID-19 growth rate for Sweden, South Korea, Italy and Germany from the excess mortality. We use the average growth rate obtained for Sweden and South Korea, two countries with lrNPIs, to estimate additional death numbers in Germany and Italy (two countries with mrNPIs) in a hypothetic lrNPIs scenario.ResultsThe growth rate estimated from excess mortality decreased faster for Germany and Italy than for Sweden and South Korea, suggesting that the mrNPIs have a non-negligible effect. This is not visible when the growth rate is calculated using the reported case numbers of COVID-19. This results in approximately 4 500 and 12 000 more death numbers for Germany and Italy, respectively.ConclusionThe reproduction numbers or growth rates obtained from reported COVID-19 cases are most likely biased. Expanding testing capacity led to an overestimation of the growth rate across all countries analyzed, masking the true decrease already visible in the excess mortality. Using our method, a more realistic estimate of the growth rate is obtained. Conclusions made for the reproduction number derived from the reported case numbers like the insignificance of most restrictive non-pharmaceutical interventions (lockdowns) might be wrong and have to be reevaluated using the growth rates obtained with our method.

REARING OF DAIRY CALVES ON PASTURE WITH OR WITHOUT WHOLE OATS

1967 ◽  
Vol 47 (3) ◽  
pp. 211-216
Author(s):  
A. D. L. Gorrill
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Growth Rates ◽  
Dairy Calves ◽  
Average Growth Rate ◽  
Average Growth ◽  
Bull Calves ◽  
Body Weights ◽  
Weight Gains ◽  
Average Body

Three groups of 10 Ayrshire bull calves born in May and June, 1963 were placed on pasture at 2 weeks of age, after weaning at 55 kg body weight, or at 15 weeks of age. Half the calves in each group also received whole oats while on pasture to a maximum of 1.4 kg/day. Prior to going on pasture, calves were fed a starter ration and timothy hay. The calves were removed from pasture at 21 weeks of age and fed hay and grain until 52 weeks of age. There were no differences between groups in rate of gain from 1 week of age to weaning, the average growth rate for all calves being 427 g/day. Calves put on pasture after weaning gained 223 g/day from weaning to 15 weeks of age, and calves put on pasture at 15 weeks of age gained only 177 g/day from 15 to 21 weeks of age. Weight gains during these same two periods for calves put on pasture at 2 weeks of age were 432 and 500 g/day, respectively. Feeding oats to calves on pasture did not increase growth rates to weaning or to 15 weeks of age. Average body weights at 52 weeks of age were 251, 228, and 242 kg, respectively for calves started on pasture at 2 weeks of age, after weaning, and at 15 weeks of age.

scholarly journals Inherent random fluctuations in COVID-19 outbreaks may explain rapid growth of new mutated virus variants

2021 ◽  
Author(s):  
Kenneth Bodin ◽  
Joacim Rocklov
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Rapid Growth ◽  
Virus Genome ◽  
Average Growth Rate ◽  
Average Growth ◽  
Virus Variant ◽  
Profound Impact ◽  
The Uk ◽  
Random Fluctuations

A new virus variant of SARS-COV-2 has had a profound impact on society while governments have taken action to limit its impacts by enforcing lockdowns and limiting spread from the UK to other countries. Variants with mutations in the virus genome are likely to occur, but do not always associate to significant changes in the biology of the virus, or the disease. For the variant VOC 202012/01 (also referred to as B.1.1.7), however, preliminary reports indicate it may be more transmissible. Here we use a simulation model calibrated to the inherent random fluctuating transmission pattern of COVID-19 to investigate what the probability may be for detecting more transmissible virus variants post facto. We find that post facto identification of successful virus variants of SARS-COV-2 are likely to exhibit growth rates that are substantially larger than the average growth rate. This finding has implications for interpreting growth rate and transmissibility of new virus variants.

Influence of Initial Seedling Size and Rate of Nitrogen Fertilizer on the Growth of Containerized Pecan Trees

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 451d-451
Author(s):  
Nolan Farace ◽  
C.E. Johnson
Keyword(s):  
Growth Rate ◽  
Nitrogen Fertilizer ◽  
Growth Rates ◽  
Average Growth Rate ◽  
Average Growth ◽  
Seedling Size ◽  
Ph Range

Pecan seedlings were randomly selected and divided into two lots according to size. Seven rates and three sources of nitrogen based fertilizers were applied four times starting on 6 May, 20 June, 4 July, and 15 Aug. Leachates were taken 3 weeks after each application. The pH range after the first application ranged from 6.0 to 7.0. After the fourth the pH had dropped to a range of 5.0 to 6.0. The TDS ranged from 0 to 6.0 mS after the first application to a 2.1 to 0.5 mS after the last application. Growth rates varied slightly among treatments. The average growth rate among seedlings was only slightly affected by nitrogen fertilize rates. Within 12 weeks the average growth was 1.3 mm. There were only slight differences in growth between the low and high rates of NH4·NO3 fertilizer. The growth rate decreased somewhat in response to increased rates of application of Ca·NO3.

scholarly journals The Two Growth Rates of the Economy

2020 ◽  
Author(s):  
Alexander Adamou ◽  
Yonatan Berman ◽  
Ole Peters
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
The United States ◽  
Ensemble Average ◽  
Gdp Per Capita ◽  
Average Growth Rate ◽  
Average Growth ◽  
Starting Point ◽  
Time Average ◽  
Per Capita

Economic growth is measured as the rate of relative change in gross domestic product (GDP) per capita. Yet, when incomes follow random multiplicative growth, the ensemble-average (GDP per capita) growth rate is higher than the time-average growth rate achieved by each individual in the long run. This mathematical fact is the starting point of ergodicity economics. Using the atypically high ensemble-average growth rate as the principal growth measure creates an incomplete picture. Policymaking would be better informed by reporting both ensemble-average and time-average growth rates. We analyse rigorously these growth rates and describe their evolution in the United States and France over the last fifty years. The difference between the two growth rates gives rise to a natural measure of income inequality, equal to the mean logarithmic deviation. Despite being estimated as the average of individual income growth rates, the time-average growth rate is independent of income mobility. (Stone Center on Socio-Economic Inequality Working Paper)

AGGREGATION IMPACT ON THE FILTRATION AND GROWTH RATES OF MUSSELS MYTILUS GALLOPROVINCIALIS LAM.

2017 ◽  
Author(s):  
Elena Vasechkina ◽  
Elena Vasechkina ◽  
Irina Kazankova ◽  
Irina Kazankova
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Clearance Rate ◽  
Mytilus Galloprovincialis ◽  
Natural Populations ◽  
Individual Variability ◽  
Clearance Rates ◽  
Average Growth Rate ◽  
Average Growth ◽  
Animal Size

This study presents the results of field and laboratory-based experiments performed to determine the mussel density effect on an individual mollusk’s growth and clearance rates. We measured the weight and length growth rates of single and aggregated mussels exposed into the sea for three monthly periods in summer and autumn 2015. The sample group contained 140 mollusks from natural populations within the length range of 15-20 mm. The average growth rate of aggregated mussels was almost the same as the growth rate of single ones. Clearance rate of single and aggregated mussels was measured in the laboratory using indirect method. There were selected 5 groups of mussels within the length ranges: 12-16 mm, 17-18 mm, 18-25 mm, 22-23 mm, and 35-38 mm. The clearance rate was measured for each mussel from the group and then for the whole group aggregated in a clump. Water temperature and seston concentration were the same for single and clumped mollusks. The volume of water in chambers was proportional to the weight of mussels put in water. The ratio of aggregated and single mussels’ clearance rates varied from 0.48 to 0.85 at the same density of aggregation and without regard to the animal size. Significant individual variability was recorded in all field and laboratory-based experiments.

AGGREGATION IMPACT ON THE FILTRATION AND GROWTH RATES OF MUSSELS MYTILUS GALLOPROVINCIALIS LAM.

2017 ◽  
Author(s):  
Elena Vasechkina ◽  
Elena Vasechkina ◽  
Irina Kazankova ◽  
Irina Kazankova
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Clearance Rate ◽  
Mytilus Galloprovincialis ◽  
Natural Populations ◽  
Individual Variability ◽  
Clearance Rates ◽  
Average Growth Rate ◽  
Average Growth ◽  
Animal Size

This study presents the results of field and laboratory-based experiments performed to determine the mussel density effect on an individual mollusk’s growth and clearance rates. We measured the weight and length growth rates of single and aggregated mussels exposed into the sea for three monthly periods in summer and autumn 2015. The sample group contained 140 mollusks from natural populations within the length range of 15-20 mm. The average growth rate of aggregated mussels was almost the same as the growth rate of single ones. Clearance rate of single and aggregated mussels was measured in the laboratory using indirect method. There were selected 5 groups of mussels within the length ranges: 12-16 mm, 17-18 mm, 18-25 mm, 22-23 mm, and 35-38 mm. The clearance rate was measured for each mussel from the group and then for the whole group aggregated in a clump. Water temperature and seston concentration were the same for single and clumped mollusks. The volume of water in chambers was proportional to the weight of mussels put in water. The ratio of aggregated and single mussels’ clearance rates varied from 0.48 to 0.85 at the same density of aggregation and without regard to the animal size. Significant individual variability was recorded in all field and laboratory-based experiments.

Survival and growth of understory trees in oak forests of the Hudson Highlands, New York

1981 ◽  
Vol 11 (3) ◽  
pp. 689-695 ◽  
Author(s):  
Craig G. Lorimer
Keyword(s):  
New York ◽  
Growth Rates ◽  
Red Oak ◽  
Northern Red Oak ◽  
Average Growth Rate ◽  
Average Growth ◽  
Red Oaks ◽  
Oak Trees ◽  
Survival And Growth ◽  
Understory Trees

Mortality and growth rates of trees in various crown classes and size classes were analyzed from 40-year permanent plot records of slope and ravine forest dominated by chestnut oak (Quercusprinus L.) and northern red oak (Quercusrubra L.). Average 5-year mortality rates for suppressed trees ≥2.5 cm dbh of chestnut oak and red oak in the slope forest were 26 and 45%, respectively. None of the suppressed red oaks survived the 40-year period, compared with 14% of the chestnut oaks and 33% of the red maples (Acerrubrum L.). Mortality of oak trees in the intermediate crown class was less than half that of suppressed trees, but still much higher than that of maples and birches on the tracts. Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year. Curves and equations expressing average mortality and growth rates at various levels of competition are presented for each species.

scholarly journals Growth rate of african catfish (Clarias gariepinus) and plankton diversity in ponds under organic and inorganic fertilization

2021 ◽  
Vol 21 (02) ◽  
pp. 17545-17559
Author(s):  
PA Otieno ◽  
◽  
DO Owiti ◽  
PO Onyango ◽  
◽  
...  
Keyword(s):  
Growth Rate ◽  
Clarias Gariepinus ◽  
Chicken Manure ◽  
Average Weight ◽  
African Catfish ◽  
Phytoplankton Species ◽  
Inorganic Fertilizers ◽  
Average Growth ◽  
Plankton Diversity ◽  
And Control

Aquaculture offers the opportunity for safeguarding local and global food security in the face of declining capture fisheries. However, the form of aquaculture that is commonly practiced in Kenya is characterized by the use of agrochemicals such as fertilizers that negatively impact biodiversity especially when effluents from fish ponds drain into water bodies. This study aimed to determine differences in the growth rate of Clarias gariepinus, an important aquaculture fish in Kenya, to assess plankton diversity, and to identify phytoplankton species associated with pollution under organic and inorganic fertilization regimens using chicken manure, Diammonium phosphate, and urea, respectively. Average growth rate calculated per day was higher in the organically-fertilized ponds at 0.06 cm/day, followed by inorganically-fertilized ponds at 0.05cm/day and then, the control at 0.04 cm/day. Average weight gain was higher in organically-fertilized ponds at 0.08 g/day followed by ponds fertilized with inorganic fertilizer at 0.07 g/day and the control, at 0.06g/day. There were significant differences in growth rate across fertilization regimens (length: F2, 264= 24.06, p = 0.0399; weight: F2, 264 = 20.89, p = 0. 0457). Specifically, although differences in growth rate of fish in organically and inorganically fertilized ponds were not significant, fish in fertilized ponds were on average, longer and weighed more than those in the control pond. Jaccard’s similarity index for phytoplankton was highest (0.38) between organically-fertilized ponds and control but lowest (0.25) between inorganically-fertilized ponds and control. Use of chicken manure produced the highest diversity of zooplankton (Shannon-Weiner’s H in organically-fertilized pond = 1.886; inorganic = 1.044, and control = 0.935). The use of DAP and urea produced the highest proportion of phytoplankton species associated with pollution. These results do not support the commonly reported notion that ponds fertilized using inorganic fertilizers are more productive. Findings suggest that the use of inorganic fertilizers may threaten biodiversity in aquatic ecosystems through the production of toxic algae.

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