Sheep production

21/09/2022

24/08/2022

HOW WOOL IS MADE - A SHEEP'S STORY
Most people know that wool comes from sheep, but how it transforms from a sheep’s fluffy coat to material that’s ready to be worn is a journey. Wool goes through a multi-step process to clean it, regularize it, and transforms it into soft yarn. Although machinery can make the process much faster today, in most ways the process is the same as how people have been preparing wool for centuries.
Shearing the Sheep
Every year, at the end of winter, sheep farmers shear their sheep, using an electric tool similar to a razor that removes all of the sheep’s fleece in one piece. A single sheep’s annual fleece can weigh over 8 kilos, although most are around 3-4kgs. When done with care, shearing doesn’t harm the sheep – a key priority of our wool vendors at Baabuk. Shearing leaves them with a thin, cool coat for the summer months. Without shearing, the sheep’s fleece can severally overgrow, such as the famous case of “Shrek the Sheep”.
The wool is then sorted and prepared for cleaning.
Cleaning the Wool
A simple step of washing the wool with removes dirt, other contaminants, and natural oils from the wool. Some of these byproducts of cleaning the wool get used for other purposes. Lanolin, a wax secreted by sheep that helps to protect their wool, is included in many beauty products such as skin moisturizer.
Carding the Wool
Next, the wool fibers go through carding, a process that pulls them through fine metal teeth. Sheep wool is naturally curly; carding straightens out the fibers and makes them soft and fluffy. Originally, carding would be done by hand using two metal combs. Today, most manufacturers use machines to card large batches of wool more quickly. By the end of carding, the wool fibers are
lined up into a thin, flat piece. These sheets can then be drawn into long, thin pieces called rovings
Spinning the Wool into Yarn
Spinning turns the wool pieces into a material that’s usable. Spinning uses a wheel to spin 2-5 strands of wool together. This forms long, strong pieces of wool that you would recognize as yarn. Different processes create different kinds of yarn that work for distinct final products. Worsted spinning, for example, makes a smooth, thin yarn that’s perfect for suits and other garments made with the finer material. Woolen spinning, on the other hand, makes a thicker yarn that’s perfect for knitting.
Weaving and Knitting
Some wool yarn is sold directly to consumers, who use it to craft hand-made scarves, sweaters, and other clothing. Other yarn forms the raw material for all kinds of wool products, from shoes to coats. It’s woven into pieces of fabric that are ready to be shaped by fashion designers.
Dyeing
Wool quickly absorbs water, which makes it very easy to dye. It can be dyed at almost any stage of the process, depending on what the final product will be. Simply submerging the wool into boiling water with the dye material, or applying colorful dyes directly to the fabric, produces the desired color.
The process of transforming a sheep’s fleece into soft and cozy wool is truly an art form that needs to be carefully managed. Although the process can be time-consuming, the end product carries many natural benefits. We’re proud to produce our sneakers, slippers, and boots with quality as the primary objective, from 100% natural wool – no blends and no compromises

24/08/2022

A single sheep, on average, provides around 4.5 kg of wool per year, the equivalent of 10+ metres of fabric. This 4.5 kg of wool is enough to make six sweaters, three suit and trouser combinations, or the fabric to cover one large sofa.
Sheep are domestic animals raised on farms for their wool, meat and milk. Along with goats, pigs and cattle, sheep were among the first animals to be domesticated.
Wool sheep are classified as Ovis aries aries. Merino, Rambouillet, Blue Faced Leicester, and Corriedale breeds are among the best-known wool sheep.
There are hundreds of sheep breeds …
Some sheep breeds are raised for their meat, others for their wool, others for both. The Texel and Dorset breeds are good choices for meat production. But there are literally hundreds of sheep breeds.
All wool can be used
Wool can be used for different purposes, depending on the coarseness of the fibre and on other characteristics such as fibre length and crimp. Very fine wool is primarily used for clothing while coarser wool is used in carpets and furnishings such as curtains or bedding.
Quick Wool & Sheep Facts
A single sheep, on average, provides around 4.5 kg of wool per year, the equivalent of 10+ metres of fabric.
This 4.5 kg of wool is enough to make six sweaters, three suit and trouser combinations, or the fabric to cover one large sofa.
World sheep numbers in 2021 rose to 1.266 billion head, up from 1.263 billion head in 2020.
China has the largest sheep population, followed by India, Australia and Sudan

09/08/2022

Vegetation control
Using sheep for custom grazing could prove to be the most profitable sheep enterprise. While the demand for lamb and wool seems limited, society seems willing to spend "unlimited" amounts of money to enhance the environment. Increasingly sheep (and goats) are being viewed as a natural and environmentally-friendly way to manage landscapes. At the same time, land managers don't want to own sheep. They want to contract grazing services.
There are many factors to consider when developing a fee-based grazing business: cost of fencing, water supply, the need to check animals daily, and a place to keep the sheep when they're not on a job. Fencing is the usually the major constraint. Predators may present a problem in remote locations. If the site is in view of the public, the public may expect the sheep to have access to shelter. It is a good idea to vaccinate sheep for rabies; it may be required.
While any kind of sheep can be used for grazing and vegetation control can be combined with production, a flock of mature wethers could prove to be the best choice. They are easier to manage and can be pushed to eat undesirable plant species without adversely affecting productivity.
Over the years, sheep have been used to control unwanted vegetation in orchards, vineyards, cemetaries, and on Christmas tree plantations. They have grazed under power lines, in national parks and historic battlefields, at ski resorts, and in urban settings. They have been used for noxious w**d control. Compared to goats, they are easier to contain, easier to handle, less destructive, and do a better job maintaining grassy landscapes. However, goats are a better choice to control brush, shrubs, and tree seedlings.

09/08/2022

Club Lambs
Some sheep farms specialize in the production and sale of club lambs. Club lambs are "feeder" lambs (ewes or wethers) that youth purchase to develop as market lamb projects to exhibit at county and state fairs, regional and national shows. Market lamb projects are usually "terminal," meaning they start with the purchase of a lamb and end with the sale of the lamb for slaughter.
While any lamb can be shown as a market lamb class, certain breeds will usually be more competitive, unless lambs are shown by breed. Heavy muscled lambs that finish over 125 lbs. are usually the most competitive in the show ring and in championship drives. Hampshires, Suffolks, and crosses between these two breeds are the most common type of club lamb, as well as the most competitive.
Dorsets, Southdowns, and Shropshires can also make good club lambs. Some shows separate lambs by weight increments, while others separate lambs by breed. Some shows collect carcass data on lambs and award additional prizes to youth participants. In live shows, judges don't always pick the lambs that will hang the best carcasses. Judging is very subjective and often the result of the lastest fad(s).
Some practices often employed in the club lamb sector may be distasteful to some people, e.g. lack of forage in the diet, late castration, ultra-short tail docking, and forced exercise. The important thing to remember about a club lamb project is that it is a youth project intended to teach young people valuable life skills. To put winning (at all costs) above youth development is sadly missing the point.

09/08/2022

Many sheep farms specialize in the production and sale of seedstock or breeding stock. Breeding stock may include ewes and rams, purebred registered animals, or commercial crossbreds. Customers for breeding stock may be other seedstock producers or commercial sheep producers.
In areas where there is a large commercial sheep industry, producers may be able to establish a demand for commercial rams. One option for selling rams is to participate in Central Ram Performance Testing Programs. In a ram test, rams are evaluated for various traits including growth, feed efficiency, wool traits, parasite resistance, and breeding soundness. Rams that don't meet performance standards are not allowed to sell. Consignment sales, production sales, and private treaty sales are other means of selling breeding stock.
Record keeping is an important aspect of seedstock production. The National Sheep Improvement Program (NSIP) is quantitative genetic evaluation program for small ruminant producers. It calculates EBVs (estimated breeding values) for various traits and allows the comparison of sheep from different flocks under different feeding and management systems. NSIP data is processed by Australia's LAMBPLAN. Producers can also do their own on-farm record keeping. There are various computer programs available for this purpose. A spreadsheet can also be used. There are apps for mobile devices.
Nowadays, it is recommended that breeding rams, especially those sold to other seedstock producers, be blood tested for scrapie genotype. Rams with susceptible genotypes (e.g. QQ) should probably not be sold for breeding, if progeny will be kept for breeding. QQ rams can be used to produce club lambs or as terminal sires in commercial flocks where all lambs will go to slaughter. Scrapie is not a genetic disease; however, an individual's genotype determines whether it will get scrapie if it is exposed to the infective agent.
Producers of breeding stock may also wish to enroll their flocks in the Voluntary Scrapie Flock Certification Program (VSFCP). The VSFCP is a monitoring program for scrapie administered by USDA-APHIS. It is usually a requirement for export of live animals.

09/08/2022

Sheep Dairying
Sheep have been milked for thousands of years and were milked long before the first cow was milked. The world's commercial dairy sheep industry is concentrated in Europe and the countries on or near the Mediterranean Sea. The dairy sheep industry is very small in the United States. Most sheep dairies are located in the Upper Midwest (Wisconsin and Minnesota), California, and the New England states.
Sheep's milk is usually made into gourmet cheeses. Some milk is made into yogurt and ice cream. Fresh sheep's milk is seldom consumed. Milk can be sold to a processor for conversion to cheese (or other products) or the milk can be processed on-farm by the producer and marketed as a value-added product.
While any breed of sheep can be milked, there are specialized dairy sheep breeds, much like there are specialized breeds of cattle and goats for dairy production. The two dairy sheep breeds raised in the US are the East Friesian and Lacaune. The Awassi, a dairy breed from the Middle East, was recently introduced to the US via embryos and semen.
Non-dairy breeds which are best adapted to dairy production are Dorset and Polypay. They only produce 100 to 200 pounds of milk per lactation, while crosses between domestic breeds and specialized dairy breeds average 250 to 650 pounds of milk per lactation. At one time, there was interest in creating a dairy hair sheep by crossing the Katahdin with the Lacaune. While not as heavy a milk producer, the Icelandic is a triple-purpose sheep.
The nutritional requirements of dairy ewes are significantly higher than for ewes being raised for meat and/or wool. Total feed requirements will depend upon genetics and length of lactation. It is important to note that some feeds can impart undesirable flavors to the milk (e.g. fish meal) and should not be fed in large quantities during lactation. Dairy ewes have the highest water requirement of any class of sheep at approximately three gallons per head per day.
While most non-dairy producers wean their lambs at 60 days of age or later, dairy lambs are usually weaned at 30 days of age or younger, so that the ewes can be milked when they are still producing significant amounts of milk. Milking facilities and equipment will be the biggest expense in a dairy sheep operation. The type of milking parlor may vary according to the size of the operation. Producers milking less than 50 ewes may utilize a platform for milking, whereas a "pit" parlor is desirable for larger operations.
After milk is cooled, it can be shipped to a processing plant or frozen for later use or shipment. While fresh milk may result in a product of slightly higher quality, frozen milk has been shown to produce very acceptable products. The ability to freeze milk on the farm and deliver large quantities to the processor at infrequent intervals allows the establishment of sheep dairies great distances from a processing plant.

09/08/2022

Wool Production
Wool was the first commodity to be traded internationally and is the product the public most commonly associates with sheep. However, the importance of wool (as a product) relative to meat has declined dramatically. In the early 1900's, the majority of income from a sheep enterprise was from the sale of wool. Today, it is the other way around. While wool is still important on many sheep farms, lambs almost always contribute the majority of income to the sheep farm. Fine wool brings the most money in the commodity market.
Selling wool in the commercial wool market has limited profit potential for most producers, but the niche marketing of wool can pay big dividends. For example, while wool sold commercially may bring only 50 cents per pound, fleeces sold to hand spinners could bring as much as $15-$20 per pound. Many producers have their wool processed into yarn, roving, blankets, or crafts and market value-added products. There are several cooperative ventures in the US that will add value to a producer's clip.
Fleeces sold to hand spinners need to be of high quality. Feeding, housing, health care, handling, and harvesting are all critical to the production of high quality wool. It goes without saying that fleeces should be skirted. Skirting is when the undesirable parts of the fleece are removed: belly wool, top knots, leg clippings, tags, stained wool, cotted wool, and short wool.
Some producers put covers on their sheep to prevent the fleeces from getting dirty and guard against the sun's ultraviolet rays, which may cause fading at the tips of colored fleeces. Since wool grows more under covers, covers have to be changed repeatedly as the fleece grows.
The marketing of fine wools is also becoming more of a niche market, as farmers and ranchers are finding ways to add value to their wool clips.

09/08/2022

Hair Sheep
The declining value of wool relative to meat, along with the decreasing number of sheep shearers, has contributed to the expansion of hair sheep, not only in the United States, but other countries as well. It is estimated that approximately 10 percent of the world's sheep population is hair sheep. According to a 2011 NAHMS study, 21.5 percent of sheep operations in the U.S. raised hair sheep breeds. Over 90 percent of the lambs that are marketed through the sale barn in San Angelo, Texas are now hair sheep.
Hair sheep naturally shed their coats (mixtures of hair and wool fibers) and typically do not require shearing, crutching, or tail docking. Hair sheep (of tropical origin) tend to be more resistant to internal parasites (gastro-intestinal worms) and other pests than wooled sheep. In addition, hair sheep breeds possess many desirable reproductive characteristics, such as early puberty, out-of-season breeding, and prolificacy.
Hair sheep are usually promoted as an "easy-care" alternative to wooled sheep and traditional high-cost production systems. Hair sheep ewes are often lambed on pasture. Lambs are commonly grass-finished. Hair sheep lambs are usually better suited to the ethnic markets than the commodity markets, which tend to prefer heavy with more finish (fat cover). At the same time, hair sheep will also work in more intensive production systems.
Because hair sheep production continues to grow, there may be a good market for hair sheep breeding stock. Many hair sheep producers sell their ewe lambs as breeding stock and their male lambs for meat.

09/08/2022

Lamb Feeding
Commercial lamb feeding is a traditional sheep enterprise in the US and is becoming more popular in other countries. In some parts of the US, lamb feeding is a seasonal enterprise, occurring primarily in the fall and winter, after pastures have stopped growing and crop residues are available for grazing. In other areas (e.g. Texas, Colorado, and the Corn Belt), lamb feed lots operate year-round. Many farmers feed their own lambs out.
In a lamb feeding enterprise, feeder lambs (50 to 100 lbs.) are purchased and fed to finish weights of 100 lbs. or more. Besides the purchase price of the lambs, the major cost of finishing lambs is obviously feed. Lambs can be finished on a variety of diets: complete pelleted rations, whole grain rations, or high-forage diets. Cheap gains can often be put on lambs on pasture or crop aftermaths. Lambs can also be finished on various by-products feeds. Distiller's grains and other co-products have been used to feed out lambs.

09/08/2022

Meat sheep producers sell either slaughter lambs or feeder lambs. Slaughter lambs are usually purchased for immediate slaughter. In the United States, the average slaughter weight for a lamb processed in a federally-inspected plant is about 136 lbs. Lambs sold into ethnic markets tend to be much lighter, usually less than 100 lbs. and often less than 80 lbs. Increasingly, there is a market for slaughter lambs of any weight.
Feeder lambs are lambs that are usually fed or grazed to heavier weights before being harvested. Feeder lambs vary in weight, usually from 50 to 100 lbs., with the demand usually being the highest for 60 to 90 lb. lambs. Increasingly, lamb feeders are having to compete with the ethnic markets for these light weight lambs.
In a meat sheep enterprise, the primary factors which determine profitability are percent lamb crop, lamb growth rates, and market prices. Unless forage resources are abundant or feed costs are very low, it is difficult to make a profit from a ewe that weans only one lamb, especially in areas where predation is high.

09/08/2022

Sheep are multi-purpose animals, raised for their meat, milk, wool, and skins. While they have been used to control unwanted vegetation for centuries, grazing as a fee-based service is a relatively new opportunity for US sheep producers. Sheep are also a popular research model and some producers have developed businesses supplying animals or other products (e.g. blood) to bio-science.
One of the first and most important decisions a shepherd must make is to decide which aspect(s) of sheep production to focus on. While most sheep breeds are multi-purpose, most are best suited to either meat, milk, or wool production -- seldom all three. Production and marketing practices usually vary according to the purpose of the flock.

28/06/2022

Tigray highland sheep owners. Discussions were made with key informants such as farmers’ representatives/elders and livestock experts in the Bureau of agriculture and rural development.
Data pertaining to common Tigray highland sheep were collected through a household survey. A total of 480 household heads (30 per rural kebelle) were randomly selected and interviewed using structured questionnaires developed from previous researcher [5]. Before conducting the formal survey, the questionnaire was pre tested and modified to match with the study area’s livestock production system and for its appropriateness. The survey was carried out by enumerators under close supervision and participation of the researcher. From the field survey, information on general household characteristics, purposes of keeping sheep, common Tigray highland sheep flock structure, breeding system and selection criteria, disposal and acquisition of sheep were gathered and documented as per the questionnaires developed and pre-tested. The discussion made with the key informants were focused on collecting data pertaining to the production system and potential breeding tract of the common Tigray highland sheep breed.
2.3. Data Analysis
Statistical Package for Social Sciences (SPSS, Corp.21, Release, 2012 [6] ) was used to analyze the survey data (household information, sheep husbandry and diseases management practice, feeding practice, purpose of sheep keeping, production constraints, selection criteria, acquiring and disposal of sheep), while data for land holding per-household, flock structure and reproductive performances were subjected to analysis of variance (ANOVA) using the general linear model procedure of SAS version 9.2 (2008 ). Tests of statistical significance or otherwise of particular mean comparisons were done with Duncan’s multiple range test. Indices were calculated for all ranking data using the formula: Index = Σ[3 for rank 1 + 2 for rank 2 + 1 for rank 3] given for an individual reason divided by Σ[3 for rank 1 + 2 for rank 2 + 1 for rank 3] for all reasons where indices represent weighted averages of all rankings for a particular trait or reason
Mixed crop-livestock production system is the dominant farming system in the study areas. Livestock production is subsistence-oriented and it is a traditional type which is characterized by minimal inputs like in the other parts of Ethiopia. It was demonstrated that low input production system is found in all livestock production systems prevailing in the country except in peri-urban and urban system [9]. Table 1 presents some key characteristics of the respondents across the study districts. The overall average age of the household head was 48.33 ± 9.16 years, implying that the respondents were adults with a good experience in

28/06/2022

A study was undertaken to identify the production system, breeding practices and major production constraints of common Tigray highland sheep in 16 rural kebelles from eight districts of Tigray Regional State. A total of 480 households (30 households for each rural kebelle) were selected purposively to collect data through personal observations and a detailed structured questionnaire. Mixed crop-livestock production system was the dominant farming system in all the study districts. The farmers kept a variety of livestock species including sheep, goats, cattle, chickens horse, donkeys and bee colony. Sheep, principally as source of income, meat for home consumption, production of manure and for socio cultural purposes, are commonly herded with other species in the open grazing fields by young boys in a family. Mating was generally uncontrolled. Body size, growth rate and adaptability were the major traits in selecting rams, whereas ewes were selected based on body size, twining ability and lambing interval. Majority of sheep across all districts are housed in structures known as Gebella which is built from stone and mud wall and tree/corrugated iron sheet roofing separated from the main family house. The major constraints hampering sheep production in the study areas were feed shortage (0.25), lack of capital (0.24), insufficient veterinary services (0.2), limited grazing land (0.2), water scarcity (0.06) and predators (0.05) with index value indicated in parenthesis. In order to improve the productivity of sheep, it is important to involve farmers and other stockholders in addressing these constraints and designing breed improvement interventions, considering the overall farming and breeding practice of smallholders.

28/06/2022

Sheep production is one of the main enterprises in mixed-crop livestock system in Ethiopia. Sheep production provides food, cash income and manure to the smallholder farmers. Smallholder farmers rear sheep mainly for two purposes: for cash income and slaughter for home consumption during festivals.

26/10/2021

Atsbie-Wemberta, Degua-Tembien, Ganta-Afeshume and Wukro-keleteAwelaelo districts hold lower number of sheep. This variation in livestock holding is partly related to the average land holding which has a bearing on availability and size of grazing and/or browsing lands, crop residues and crop aftermath as the main feed sources of small holder livestock producer’s. Similar result for sheep holding was reported for highland sheep in Lallo Mama Midir in the central highlands [13] and Gumuz sheep in Amhara region [14] of Ethiopia. The number of sheep per household reported in the present study is larger than the sheep flocks in the mixed crop livestock production system of the western highlands of the Amhara Regional State [15].

3.4. Sheep Husbandry Practice

Husbandry practices have an implication for designing genetic improvement programs and introducing improved sheep management such as strategic health interventions at village level [16]. The flock herding practices of the smallholder farmers reflects the breeding managements and has an impact on the flock size.

3.4.1. Housing System and Herding Practice

According to the result, 64.4%, 29.6% and 6.0% of households are housing their sheep in closed, semi-closed and open
housing type respectively (Table 3). Majority of sheep across all districts are housed in houses separated from family

26/10/2021

sheep farming. The overall mean family size was 6.49 ± 2.65, which is comparable with the estimation of 6.4 persons per household reported in other area [10]. Among the total household heads, 75.0% were males, which is comparable to the result reported by earlier researchers [11] [12]. Household headed by female in the present study is high, which could be attributed to the death of mainly males in the prolonged internal conflict during the Derg regime and border dispute between Eritrea and Ethiopia.

The majority of the respondents (94.4%) were follower of Ethiopian Orthodox Christianity, while the remaining (5.6%) were Muslims. The overall literacy rate among the household heads was 67.4%. Small holder farmers close to the regional capital Mekelle have higher (82.9%) while those in Alamata (55.0%) and Offla (53.4%) recorded lower literacy rate. This variation could be due to the distance to the urban centers, since education facilities in such areas are likely better for offering chance to the residents to educate themselves and their children. The presence of better educational background in this study would be a good opportunity for enhancing animal genetic improvement programs in the study areas, since literate communities are more likely better to adopt and practice new technologies and also to keep performances records of animals. The present findings indicate that sheep farming is performed by every social class of the community regardless of their background characteristics and show the significant importance of sheep to the producers.

3.2. Land Holding and Farm Activities

The overall average landholding per household in the study areas was 1.0 ± 0.8 hectare (Table 2). There is significant (P < 0.05) difference between the districts. Alamata, Enderta and Mekelle area districts have larger land holding while households in Atsbie-Wemberta, Wukro-keleteAwelaelo, GantaAfeshume, Degua-Tembien and Offla have smaller landholding with no significant difference in land size among these districts. This result shows that the average land holding size per household in the mid altitude was higher than high altitude due to the dense population in the later. Almost all respondents across the study areas indicated that the trend of land holding size per household is decreasing over time. Human population growth rate, expansion of the existing town and newly established town, establishment of governmental institutes, land degradation and soil erosion are some of the mentioned factors contributing to the declining landholding per house hold across all districts. The average landholding reported in this study was greater than 0.5 ± 0.53 hectare reported for Atsbie-Wemberta district

26/10/2021

Mixed crop-livestock production system is the dominant farming system in the study areas. Livestock production is subsistence-oriented and it is a traditional type which is characterized by minimal inputs like in the other parts of Ethiopia. It was demonstrated that low input production system is found in all livestock production systems prevailing in the country except in peri-urban and urban system [9]. Table 1 presents some key characteristics of the respondents across the study districts. The overall average age of the household head was 48.33 ± 9.16 years, implying that the respondents were adults with a good experience in

26/10/2021

Data pertaining to common Tigray highland sheep were collected through a household survey. A total of 480 household heads (30 per rural kebelle) were randomly selected and interviewed using structured questionnaires developed from previous researcher [5]. Before conducting the formal survey, the questionnaire was pre tested and modified to match with the study area’s livestock production system and for its appropriateness. The survey was carried out by enumerators under close supervision and participation of the researcher. From the field survey, information on general household characteristics, purposes of keeping sheep, common Tigray highland sheep flock structure, breeding system and selection criteria, disposal and acquisition of sheep were gathered and documented as per the questionnaires developed and pre-tested. The discussion made with the key informants were focused on collecting data pertaining to the production system and potential breeding tract of the common Tigray highland sheep breed.

2.3. Data Analysis

Statistical Package for Social Sciences (SPSS, Corp.21, Release, 2012 [6] ) was used to analyze the survey data (household information, sheep husbandry and diseases management practice, feeding practice, purpose of sheep keeping, production constraints, selection criteria, acquiring and disposal of sheep), while data for land holding per-household, flock structure and reproductive performances were subjected to analysis of variance (ANOVA) using the general linear model procedure of SAS version 9.2 (2008 [7] ). Tests of statistical significance or otherwise of particular mean comparisons were done with Duncan’s multiple range test. Indices were calculated for all ranking data using the formula: Index = Σ[3 for rank 1 + 2 for rank 2 + 1 for rank 3] given for an individual reason divided by Σ[3 for rank 1 + 2 for rank 2 + 1 for rank 3] for all reasons where indices represent weighted averages of all rankings for a particular trait or reason