The influence of age structure on total productivity in breeding flocks of Merino sheep. I. Flocks with a fixed number of breeding ewes, producing their own replacements

1968 ◽  
Vol 19 (3) ◽  
pp. 443 ◽  
Author(s):  
HN Turner ◽  
GH Brown ◽  
GH Ford
Keyword(s):  
Age Structure ◽  
Age Groups ◽  
Fixed Number ◽  
Reproduction Rate ◽  
Fixed Size ◽  
Young Stock ◽  
Merino Sheep ◽  
Total Productivity ◽  
Two Age Groups

In a flock of breeding ewes of fixed size, the number of age groups of rams and ewes influences the annual rate of genetic gain in any character under selection. The number of ewe age groups also influences the number of surplus stock aged 1½ years, and the number cast for age, as well as the amount and quality of wool obtained. The latter is also influenced by the proportion of ewes which rear no lambs, one, or two, as well as the proportion themselves born in multiple births or as the progeny of young ewes. In this paper, all these influences are considered in determining the age structure of the breeding flock which gives the greatest number of surplus stock and the greatest relative wool return. To combine the two, relative weights have to be given to wool and surplus stock. One such set of weights has been used, and the conclusion has been drawn that two age groups of rams, with either five or six age groups of ewes, give optimal return, the number of ewe groups depending on the level of reproduction rate. This conclusion depends on the relative weights used. In cases where numbers of animals are of supreme importance, such as after a drought or at a time of increasing pasture improvement, then retaining ewes to an older age would increase the number of surplus young stock.

Effect of Merino sheep age on consumer sensory scores, carcass and instrumental meat quality measurements

2019 ◽  
Vol 59 (7) ◽  
pp. 1349 ◽  
Author(s):  
L. Pannier ◽  
G. E. Gardner ◽  
D. W. Pethick
Keyword(s):  
Meat Quality ◽  
Age Groups ◽  
Age Effect ◽  
Eating Quality ◽  
High Quality ◽  
Merino Sheep ◽  
Longissimus Lumborum ◽  
Quality Measurements ◽  
Two Age Groups

Slower growing Merino sheep often miss the lamb category and become yearlings. Yet, they may still produce meat of acceptable eating quality, thus opening the opportunity to develop high quality yearling products. Consumer sensory differences (tenderness, overall liking, juiciness, liking of flavour and liking of odour) of grilled wet-aged (5 days) steaks from the M. longissimus lumborum (LL) and M. semimembranosus (SM) derived from wether lamb (n = 185; average age 355 days) and wether yearling (n = 206; average age 685 days) Merinos were tested. Additionally, the age effect on carcass and instrumental meat quality traits was analysed. Lambs were born in 2009 and 2010 at two research sites (Kirby, Katanning), and yearlings were born in 2009 at five research sites (Kirby, Cowra, Rutherglen, Struan, Katanning). On average within each muscle, yearlings had lower scores for all sensory attributes (P < 0.01) compared to lambs. Lambs versus yearlings born in the same year and reared at the same research site had greater sensory differences within the SM (P < 0.01), up to 10.0 eating quality scores more for tenderness. In contrast, the LL samples had almost no significant differences between the two age groups. A portion of the differences in overall liking and liking of flavour scores was explained by intramuscular fat. Yearlings were slightly heavier (P < 0.01) but leaner (P < 0.01), compared to lambs, and yearling meat colour was darker (P < 0.01). While the results generally supported the better eating quality of lamb, they demonstrated a very acceptable yearling LL eating quality, and showed the smaller impact of age on the LL muscle in Merinos. Hence, the development of a high quality yearling product for the LL muscle is possible.

scholarly journals EFFECT OF FREEZING ON THE MILK QUALITY OF COWS

2020 ◽  
pp. 54-57
Author(s):  
Lyubov Valentinovna Efimova ◽  
Tatyana Vyacheslavovna Zaznobina ◽  
Elena Vladimirovna Gatilova ◽  
Olga Valeryevna Ivanova
Keyword(s):  
Quality Indicators ◽  
Age Groups ◽  
Milk Quality ◽  
Long Term Storage ◽  
Before And After ◽  
Frozen State ◽  
Term Storage ◽  
Two Age Groups

Due to the fact that milk has a short shelf life, the issue of its freezing and long-term storage in the frozen state is relevant. A study was conducted on the effect of freezing on the milk quality after its defrosting of cows-mothers and cows-daughters of Red-Motley breed. As a result, it was established how milk quality indicators to change after five months of storage in a frozen state in cows of two age groups. A high correlation was established between quality indicators before and after freezing. The influence of the “freezing” factor on milk quality indicators was recognized statistically significant, the “generation” factor – not significant.

The age distribution in the Taimyr population wild northern deer (Rangifer Tarandus) in the first decades of 21 centuries

2021 ◽  
pp. 15-21
Author(s):  
A. Shapkin ◽  
R. Ivanova ◽  
N. Arsentseva ◽  
N. Sukhanova
Keyword(s):  
Age Structure ◽  
Rangifer Tarandus ◽  
Age Distribution ◽  
Age Groups ◽  
Base Material ◽  
Middle Level ◽  
Reproduction Rate ◽  
Male And Female ◽  
Field Samples ◽  
Wild Deer

Objective: mathematical demography means to identify and evaluate the age distribution of male and female of Taimyr tundra reindeer in the first decade of the XXI century and future trends in demographic situation Taimyr population.Materials and methods. The base material for evaluating the current state of the population age structure Taimyr steel fishing representative sample of male and female wild deer (n = 10845 individuals) collected in the West, Central and Taimyr Putorana in 2001-2008., And the deer samples (n = 1569 individuals), the floor of which is unknown. Determination of individual animals from age and older (n = 9773 individuals) performed on histological sections of cutters according to the corresponding procedure. To repay the random deviations of sample data because of a lack of presence of immature animals (calves, yearlings, young 1-2 years) (selectivity of fishing is directed primarily at the production of individuals older than 3 years, why animals in different age groups in the samples is greater than there are in the population) applies a smoothing procedure. Then, positive deviation of the number of individuals in the same age group were leveled due to negative deviations in adjacent groups.Results. By smoothed age ranges of the field samples from 2001-2008 the current age distribution of Taimyr wild reindeer calculated and analyzed. The study showed that the theoretical current age distribution of males with realized breeding is 77.03, females - 80.56, in the combined groups of animals - 82.35%. The real population has 18-19 age generations of males and females. The reproductive core of males from 3 to 10 years old is 48.43%, individuals of age limit 11 years and older occupy 1.96% of this sex and age structure, calves and young animals for 1-2 years - 24.64%. For the reproductive part of females aged 3–15 years, the overall age distribution is 55.34%, and the proportion of juveniles and young animals, according to calculations, is determined in this part of the population at 25.16%. In the combined current age distribution, males, females: calves and young animals accounted for 27.72%, the sexually mature part with animals of older and age-specific ages - 54.63%.Conclusion. Demographic Taimir population modeling operation in the first decade of the XXI century long materials commercial samples collected at commercial points shown at current age distribution of the realized and reproduction conditions for existing commercial load males - 77.03 for females - 80.56 and for unified groups (males, females) - 82.4%. Meanwhile, the steady state and stable age distribution Taimyr tundra wild deer can reach a middle-level only when the fecundity of female reproductive generations with clean reproduction rate (R0) equal in population groupings 1.0

scholarly journals Use of GPS for Older Adults to Decrease Driving Risk: Perceptions from Users and Non-Users

Geriatrics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 60
Author(s):  
Anne E. Dickerson
Keyword(s):  
Older Adults ◽  
Global Positioning System ◽  
Risk Perceptions ◽  
Age Groups ◽  
Driving Risk ◽  
Global Positioning ◽  
Healthy Community ◽  
Ability To Drive ◽  
Two Age Groups

Community mobility is important for social participation and quality of life. Thus, it is important to sustain older adults in their communities by supporting their ability to drive as long as possible. Use of global positioning system (GPS) technology may provide such support. This descriptive study examined 89 healthy community older adults’ perspective on using and programming a GPS after using it for wayfinding to unfamiliar destinations. Participants were equally divided between two age groups (60s, 70s) and familiarity with GPS (familiar, unfamiliar). The results showed age differences in problems following GPS directions and those who were familiar found it significantly easier to use. The majority of the unfamiliar group indicated an increased interest in using GPS and were significantly more interested in training to use a GPS. Preference for learning how to use a GPS included in-person delivery and practice with troubleshooting, using the menus and changing routes as topics critical for training. The implications of these results are discussed.

scholarly journals LOW VISION DEVICES

2015 ◽  
Vol 22 (10) ◽  
pp. 1345-1350
Author(s):  
Muhammad Saad Ullah ◽  
Sohail Safdar ◽  
Muhammad Nabeel Ahmad
Keyword(s):  
Tertiary Care Hospital ◽  
Low Vision ◽  
Tertiary Care ◽  
Age Groups ◽  
Care Hospital ◽  
Age Group ◽  
Vision Assessment ◽  
Study Results ◽  
Two Age Groups

Objective: The main objective of the present study was to find out visual outcomeof Low Vision Devices among patients suffering from different diseases causing reduced visualacuity in the area of Dera Ghazi Khan, Southern Punjab, Pakistan. Setting: OphthalmologyDepartment, Dera Ghazi Khan which is a tertiary care hospital. Period: 10th February, 2014 to31st December, 2014. Material and Methods: Patients (n=55) presented for their low visionassessment included two groups age wise as patients equal or more than 18 years age (n=22)and patients less than 18 years (n=33). LOG MAR VA charts, contrast sensitivity test, visualfields through arc perimeters, color vision with color pencils hue 16 test along with objective andsubjective refractions were applied. All the data were entered and analyzed using SPSS version16.00. Results: Patients (n=55) aged 7-90 years presented for their low vision assessment hadmean age 23.73+ 2.9 years. The patients were divided into two age groups. First group was22 (40%) patients equal or more than 18 years age and second consisted of 33(60%) patientsless than 18 years age group. Among the patients examined, 40 (72.7%) were males and 15(27.3%) were females. Our study results revealed that the low vision devices provision wasassociated with a statistically significant improvement in both near and distance visual acuitiesand with patients’ fulfillment. Conclusion: There was a significant improvement in far and nearvisual acuity of the patients suffering from a multiplicity of blindness caused diseases by whichpatients are able to improve their quality of life and able to do their tasks without getting helpfrom others.

Spatial diversity of demographic aging in Poland

2016 ◽  
Vol 61 (2) ◽  
pp. 62-72
Author(s):  
Małgorzata Podogrodzka
Keyword(s):  
Age Structure ◽  
Age Groups ◽  
The Elderly ◽  
Spatial Diversity ◽  
Explanatory Variables ◽  
Younger Age ◽  
Demographic Aging ◽  
The Relationship ◽  
Test Objects ◽  
Two Age Groups

In the assessment of the demographic age and ageing a lot of measures are being exploited. Among the most commonly used may be mentioned those which express the relationship between the number of people in two age groups (the elderly and the general population or younger age group). Rarely are used such measures, which take into account all the age structure of the population. The article presents a new method to analyze spatial diversity of the population age structure using the method of agglomeration with the Euclidean metric. The test objects were the voivodships (provinces), and the explanatory variables were five-year age groups (20 variables). In addition, a hypothetical business was introduced, which has a regressive age structure. Its introduction allowed for an evaluation of how the test regions differ not only among themselves, but also how far they deviate from the pattern of development of the Polish population. Considerations were conducted separately for men and women and the 1991, 2001, 2011.

scholarly journals Effect of Age and Sex on the Quality of Offal and Meat of the Wild Boar (Sus scrofa)

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 660
Author(s):  
Agnieszka Ludwiczak ◽  
Joanna Składanowska-Baryza ◽  
Marek Stanisz
Keyword(s):  
Wild Boar ◽  
Crude Protein ◽  
Ph Value ◽  
Age Groups ◽  
Protein Ratio ◽  
Wild Boars ◽  
Effect Of Age ◽  
Age And Sex ◽  
Two Age Groups

The goal of the study was to examine the effect of age and sex on the quality of wild boar offal and meat. A number of 32 hunt-harvested animals was assigned to groups according to age (juveniles and sub-adults) and sex. The quality of offal (liver, kidneys, heart and tongue) and m. semimembranosus was examined. The pH value of m. semimembranosus ranged from 5.45 to 5.88. The highest pH was recorded in the kidney and the liver (6.32–6.54 and 6.12–6.31). The meat in the group of juveniles was brighter (p = 0.042), yellower (p = 0.039), showed a greater drip loss (p = 0.007), cooking loss (p = 0.039), and plasticity (p = 0.028), compared to the sub-adults. The extractable fat content in the m. semimembranosus and offal (p = 0.004), and water to crude protein ratio (p = 0.033), also differed between age groups. The results of the study show different quality attributes of offal and meat of wild boars from two age groups. The obtained quality measures suggest that the culinary and technological usefulness of offal and meat from the wild boars may differ according to the age of hunted animals.

Selection schemes for improving both reproduction rate and clean wool weight in the Australian Merino under field conditions

1965 ◽  
Vol 16 (5) ◽  
pp. 863 ◽  
Author(s):  
SY Young ◽  
Turner H Newton
Keyword(s):  
Theoretical Consideration ◽  
Relative Efficiency ◽  
Selection Pressure ◽  
Field Conditions ◽  
Reproduction Rate ◽  
Optimal Method ◽  
Merino Sheep ◽  
Selection Of ◽  
Australian Merino

Theoretical consideration has been given to 28 selection schemes which might readily be applied for the improvement of both number of lambs born and clean wool weight per head in Australian Merino sheep under field conditions. Two sets of relative weights were used, one lamb being considered equivalent to 5 or 10 lb of clean wool, and when both characters were selected in one sex, equal selection pressure was applied to each. Quality of wool is assumed to be safeguarded by preliminary culling of off-types. The schemes were investigated at two levels of twinning (15 and 30%). At both levels, the optimal method of ram selection was to select on clean wool weight among twin-born rams. At the lower level, the optimal method of ewe selection was to save twin-born ewes and to make up numbers by selecting on clean wool weight among those born as singles. At the higher level, this scheme was slightly exceeded in total genetic gain by one involving selection of ewes on their own 3-year-old reproduction rate. After 10 years of selection under the optimal scheme, an increase of about 40 lambs born per 100 ewes joined would be expected in reproduction rate, and about 1.2 lb clean wool in the cut per head. The gain in wool weight will be less (about 1 lb) if more rigorous culling on crimp is practiced, but the relative efficiency of the schemes near the optimum will not be changed. The tables presented could be used in flocks of any breed in which clean wool weight and reproduction rate were uncorrelated and to which approximately the same estimates of heritability, variances, and relative weights of lamb and wool could be applied.

The association between lambing status and future reproductive performance of ewes grazing oestrogenic pastures

1982 ◽  
Vol 33 (4) ◽  
pp. 711
Author(s):  
RW Ponzoni ◽  
SK Walker
Keyword(s):  
Analysis Of Variance ◽  
Age Structure ◽  
Reproductive Performance ◽  
Age Groups ◽  
Reproduction Rate ◽  
Data Set ◽  
Subsequent Performance ◽  
Regression Methods ◽  
Main Effect ◽  
Class 1

Eight flocks of ewes grazing improved pastures which contained oestrogenic clover (Trifolium subterraneum cv. Yarloop) were studied. Two data-sets were available for analysis: Data-set 1-four flocks, three with age-structure unknown. Records on the number of ewes lambing per ewe exposed to the ram (EPJ) and the number of lambs born per ewe exposed to the ram (LBJ) were collected during 1972-75. The repeatability of EPJ and LBJ were estimated within flocks by the regression methods. There was considerable variation between flocks in the values obtained. An analysis of variance was conducted including lambing status (0, 1 or 2 lambs at birth) of the ewes in 1972 as a main effect. Class 1 ewes had a better reproductive performance in subsequent years than either class 0 or class 2 ewes. The effects on flock performance of culling barren ewes were simulated, showing that little improvement in subsequent performance would result. Data-set 2-four flocks, age-structure known. EPJ and LBJ were recorded in 1973 and 1974. The repeatabilities of EPJ and LBJ were estimated within age groups of each flock by regression methods. The results were less variable than in data-set 1. An analysis of variance was conducted, including lambing status (0 or 1 lamb at birth) in 1973 as a main effect. Class 1 ewes had a better reproductive performance in 1974 than class 0 ewes. Simulation of the effects of culling ewes which were barren in 1973 showed that only a small improvement in reproductive performance of ewes in 1974 could be obtained. It was concluded that the culling of barren ewes is unlikely to provide a solution to the low reproduction rate of ewes grazing oestrogenic pastures.

E-Government in Croatia

2020 ◽  
Vol 12 (3) ◽  
pp. 85-96
Author(s):  
Jovana Zoroja ◽  
Ivan Strugar ◽  
Božidar Jaković
Keyword(s):  
Age Groups ◽  
Composite Index ◽  
Government Services ◽  
Eu Member States ◽  
Digital Performance ◽  
The Difference ◽  
High Level ◽  
The Eu ◽  
Two Age Groups

The composite index summarizing relevant indicators of Europe's digital performance and tracking the progress of EU Member States in digital competitiveness in the Croatian case, still below the EU average, especially in the area of e-government. The aim of this article is twofold. First, we evaluate the difference between respondents 18 to 24 and 25 to 34 according to their attitudes towards the usage of offered e-government solutions. Second, we determine the presence of the obstacles in using e-government solutions among these two age groups. The utilization of e-government services is still rather low, and one, a very important reason for lower usage of e-government services in Croatia is the perceived low level of quality of the e-government services with the perceived high level of obstacles towards their usage.

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