Strong Wool Research Articles

Sheep breeding in north-western arid and semi-arid regions of India: An overview

Meatconsumption in India isincreasingrapidly andthe demandwill be much higher in nearfuture. Sheep meat has scope to fulfil this gap, given a strategic planning. Sheep husbandry contributes sizeably to the livelihood and economic sustenance of farmers in rural areas especially in arid and semi-arid regions. This review pertains to sheep breeding status and prospects for north-western arid and semi-arid regions of India for enhancing productivity. These regions have 14 well-defined sheep breeds/strains and farmers mainly depend on sheep rearing for their livelihood. Breeding policies directed by state government for sheep have been developed and implemented for improvement; however the reach of the programmes is limited. Breed improvement policy for sheep needs to be looked upon as a bottom-up instead of traditional top-down approach. ICAR-Central Sheep and Wool Research Institute (CSWRI) has developed new strains and improved native sheep such as Malpura, Magra, Marwari, Chokla, Patanwadi, Sonadi, Muzaffarnagari,Avikalin, prolificAvishaan, Dumba and sheep strains resistance to Haemonchus contortus in the arid and semi-arid regions. The Avishaan, prolific sheep produce more lambs per ewe for higher profitability. Milk of sheep also needs focus and selective breeding in Patanwadi sheep for milk has potential. In India, wool production has stagnated over the decade; however, there is huge demand for good quality wool in the market. Thus, crossbreeding of Australian strong wool Merino sheep with wool sheep of western Rajasthan can prove to be a promising solution. Implementation of breeding programme is usually difficult and requires involvement of shepherd communities. Several initiatives which need attention in near future for sheep breeding are proposed in this review. State-wide or region-wide sheep identification, use of information technology for sheep data collection and linkage to market, genomic selection for traits difficulttomeasureand breeding of sheepunderclimatechangeshould begiven proper emphasis.

Wool and Carpets - 6000 Years of Innovation, Quality and Sustainability

The first manufacture of rugs with pile yarns made from animal fibres was well over 6000 years ago and the oldest carpet still in existence is around 2400 years old. The carpets and rugs sector is the major end-use of strong wool which makes up around 45% of global wool production (fine wool comprises 35% of global production).The advantages and perceived deficiencies of wool carpets in comparison with newer generation synthetic carpets are highlighted with possible solutions and new directions for research. Improvements in these areas are essential for wool to maintain its share of the carpet market.

Identification and quantitation of major structural proteins from enriched cuticle fractions of wools of different breeds

The cuticle plays an important role in determining characteristic traits of wool fibres, but little is known about the identity and abundance of its proteinaceous constituents and whether there are unique differences in cuticle composition of wools from different breeds of sheep. In this study, protein profiles of enriched endocuticle fractions from fine (Merino), strong (Romney) wool and a sheep that sheds its wool (Wiltshire) were determined by LC-MS/MS and LC-MALDI, quantitative differences being determined by iTRAQ-labelling. Although keratin composition of the cuticle was similar between breeds, with the exception of K82, there were clear differences in the number of identified keratin-associated proteins. Overall, both qualitative and quantitative differences in protein composition of the cuticle from different sheep breeds were found, which may contribute to the unique characteristics of these wools.

Worlds of wool: Recreating value off the sheep's back

AbstractRecent attempts to recreate the wealth once generated in New Zealand from wool are discussed. These attempts are theorised as active processes of assemblage within overlapping and interacting social worlds. The focus of the paper is ethnographic, engaging with the actors in worlds of wool as they experiment with ways to retain and add value by enhancing connectivity between farmer‐producers, manufacturers and consumers; delineating and capturing value by constructing new products and brands; and continually developing metrologies, making new animals and advancing an array of environmental and social values. The study focuses on fine and strong wool worlds.

The effect of nutritional stress on the wool production potential of strong and fine wool Merino sheep

The objective of this study was to investigate the effect of short-term nutritional stress after weaning on the wool production characteristics of fine vs. strong wool producing Merino sheep over the short and medium term. Forty fine wool and 40 strong wool weaner lambs were divided into two equal groups (treatment and control group) each. The treatment and control groups received diets of low and high nutritional value, respectively, for a period of three months. Thereafter the animals were kept for a further 18 months on natural pasture in the Karoo. After the first three months the body weights of the control groups were more than 12 kg heavier than those of their respective stressed groups. However, these differences in body weight were cancelled out by the end of the experiment due to compensatory growth among the treatment animals after alleviation of the nutritional stress. After the three-month stress period the fine wool group produced 42% less wool than their unstressed control group and the strong wool group only 29% less wool than their control group. However, at the end of the study the stressed animals produced the same amount of wool as their respective controls. The most important conclusion from these results is that early nutritional stress did not have a permanent detrimental effect on the wool production potential of fine or strong wool sheep. South African Journal of Animal Science Vol. 35(4) 2005: 273-281

Staple strength of fine, medium and strong wool Merino wethers under drought conditions

Fine, medium and strong wool Merino wethers (n = 72, 4 years old) were grazed together on drought-affected pastures in a semi-arid environment. In order to examine the hypothesis that restricting liveweight gains at the break of drought would improve staple strength, sheep were allocated to restricted grazing in a 5-ha paddock (drought group), or unrestricted grazing in a 20-ha paddock (drought-break group) when it was judged that the drought had broken in the region. Wool staples from all sheep broke at a point coinciding with summer rainfall events before allocation to treatment groups, and staple strength did not differ between treatments. Medium wool sheep (22.0 ± 1.6 N/ktex) produced wool of lower (P<0.001) staple strength than fine (30.0 ± 1.6 N/ktex) or strong (30.2 ± 1.6 N/ktex) wool sheep. Restricting the measurement of staple strength to the period when treatments were applied revealed no effect of treatment on staple strength, despite the fact that wethers in the drought-break group experienced a greater (P<0.001) liveweight gain (6.62 ± 0.37 kg) after allocation to their treatment than those in the drought group (–3.24 ± 0.37 kg). Staple strength was most strongly correlated with coefficient of variation of fibre diameter (r = –0.65; P<0.001); a result that was observed for all strains and treatment groups. The results indicate that coefficient of variation of fibre diameter is correlated with staple strength regardless of strain, and that management strategies designed to limit fibre diameter variability during a drought need to be applied not only at the break of a drought.

Wool production and quality of three strains of Merino in a semi-arid environment under different grazing strategies

Three strains of Merino wethers (strong, medium and fine wool; n = 30 each; 3 years old) were grazed under 3 different management regimes (10 from each strain) in a semi-arid environment to test the hypothesis that attempting to keep liveweight stable at upper and lower levels would improve staple strength relative to sheep in which no attempt was made to limit liveweight fluctuations, and that strength and wool colour would not differ between strains. Sheep in the low grazing regime were managed in an attempt to keep liveweight stable at a level below that of sheep in the high grazing regime, which were managed in an attempt to keep liveweight stable at a level higher than sheep in the low grazing regime. For the control group, no attempt was made to limit liveweight fluctuations through grazing management. Sheep in the high grazing regime had greater liveweights throughout the experiment than sheep in the low grazing regime, while the liveweight of sheep in the control group was usually intermediate. Staple strength did not differ significantly between the strains, but was greater (P<0.05) for sheep in the high grazing regime (58.3 ± 2.2 N/ktex) than for sheep in the control (39.0 ± 2.3 N/ktex) and low (33.8 ± 2.3 N/ktex) grazing regimes, which did not differ significantly from each other. Wool yellowness was not affected by grazing regime, but was lower (P<0.05) in fine wool sheep (1.0 ± 0.1%) than medium wool sheep (1.4 ± 0.1%), which, in turn, was less (P<0.05) than in strong wool sheep (1.7 ± 0.1%). Staple strength was significantly (P<0.05) correlated with mean liveweight (0.27), mean fibre diameter (0.25), minimum fibre diameter (0.36), coefficient of variation of fibre diameter (–0.50), coefficient of variation of diameter along fibres (–0.48) and between fibres (–0.41). The results indicate staple strength was not adversely affected by the choice of strain in a semi-arid environment, and that nutritional management to limit fibre diameter variability can be an effective strategy to improve staple strength, regardless of strain.

The impact of rabbits on a grazing system in eastern New South Wales. 2. Sheep production

Much research, time and money have been invested in the control of rabbits in Australia, yet the relationship between rabbit density and livestock production losses has not been quantified. We experimentally investigated the variations in sheep production parameters caused by 4 densities of rabbits, 0, 24, 48 and 72 rabbits/ha. Medium to strong wool merino wethers were run at a constant stocking rate in replicated plots with rabbits at 4� different densities. Sheep liveweight and body condition and wool production variables were measured over 3�years. Low to medium densities of rabbits were not found to reduce liveweights of wethers, whereas wethers run with the high density of rabbits were significantly lighter. The presence of rabbits reduced the body condition of sympatric sheep with the lowest body condition recorded at the high rabbit density. Mean greasy fleece weights, wool yields and clean-fleece weights were significantly different between densities of rabbits. Wethers run with the high rabbit density grew less wool than the wethers run with the other 3 densities of rabbits. The cumulative gross return per ha from wool production was highest for the medium rabbit density and lowest at high rabbit density. At the conclusion of this short-term experiment, the presence of some rabbits enhanced returns from wool production because of lower fibre diameter and comparable clean-fleece weights of fleeces grown at low and medium rabbit densities. These production characteristics might have been caused by synergistic effects on pasture growth or a sheep stocking rate that was too conservative for the prevailing seasonal conditions. At high rabbit density, competition for pasture between rabbits and sheep overrode possible synergistic and understocking effects. The economic implications of the presence of rabbits on merino sheep production are discussed.

Evaluation of genetically fine and fine x strong wool Merinos on irrigated pastures

Evaluation of genetically fine and fine x strong wool Merinos on irrigated pastures

Factors affecting pregnancy rates following laparoscopic insemination of 28,447 merino ewes under commercial conditions: A survey

The results of laparoscopic insemination of 28,447 Australian Merino ewes with semen from 468 rams were used to study factors influencing pregnancy. The overall pregnancy rate was 71.7% (20,423/28,447). Pregnancy rates varied with type of progestagen implant, type and dosage of PMSG, fresh or frozen semen, wool type and number of ewes inseminated per hour. The pregnancy rate (64.6%) obtained with Medroxy-progesterone acetate (MAP) sponges, was significantly (P < 0.01) lower than with Fluorogestone acetate 30 mg (FGA 30; 74.7%) sponges, Fluorogestone acetate 40 mg (FGA 40; 72.1 %) sponges, and Controlled Internal Drug Release (CIDR-G; 71.7%) implants. A PMSG dose of 200 IU resulted in significantly (P < 0.05) lower pregnancy rates (62.4%) compared with 250 IU (72.9%), 300 IU (79.1 %) and ≥ 375 IU (69.4%). The mean pregnancy rate for ewes administered Folligon PMSG was 71.9%, which was significantly higher (P < 0.001) than that of ewes treated with Pregnecol PMSG (65.8%). The use of Pregnecol PMSG and MAP sponges was associated, and thus their conditional effects could not be calculated. Ewes inseminated with fresh semen were significantly (P < 0.001) more likely to become pregnant (82.2%) than those inseminated with semen frozen in pellets (69.5%) or straws (71.6%). Ewes inseminated during the months of March, April or May (fall, 71.5%) were just as likely to become pregnant as those ewes inseminated in November, December, January or February (69.6%). Significantly (P < 0.05) fewer strong wool ewes become pregnant to laparoscopic AI, (67.6%) than fine (71.7%), fine medium (73%) or medium wool ewes. Significantly (P < 0.0001) more pregnancies (77.6%) were achieved when more than 55 ewes were inseminated per hour compared with fewer than 35 ewes per hour (63.4%).

Nutritional responses in wool growth by four Merino genotypes of differing wool growth performance

Sheep from four Merino flocks, different in annual clean fleece production when grazed together, were offered a range of nutritional treatments to compare their ability to digest dietary organic matter (experiment 1) and to compare the relationships of wool growth and fibre diameter with nutrient intake (experiment 2). The sheep were selected from a finewool (Fl), a strong wool (S), and two medium-Peppin (MP6 and MP10) flocks. The nutritional treatments varied intakes of two pelleted diets-B and F. Diet B consisted of oat grain, lucerne chaff, and oaten straw, while diet F was as for B but fortified with fishmeal. The digestibility of both diets was negatively related to the level of intake, and there were some differences between the flocks in their ability to digest organic matter. Clean wool growth per unit area of skin was curvilinearly related (P &lt; 0.001) to N intake, but was not influenced by diet per se. The regression coefficient for the relationship of clean wool growth with N intake and the estimated maximum wool growth rate of flock F1 were less than the other flocks. However, flock MP10 grew less wool than flocks S and MP6 at any given intake. Variation in (fibre diameter)2 accounted for 0.6 of the variation in wool growth, with responses in fibre diameter to intake being similar to those observed in wool growth. The responses in plasma cystine of the flocks to N intake differed, with the relationship for flock F1 being curvilinear and reaching a maximum at an intake of 27 g N day-1, while the responses of the other flocks were essentially linear. The relationships between plasma cystine level and wool growth differed between the flocks such that wool growth of sheep from flocks S and MP6 was more responsive to increased plasma concentration of cystine.

Wool prices and sheep breeding objectives - a historical perspective

An analysis of weekly wool prices for different fibre diameter market indicators from 1950 to 1993 was conducted to determine appropriate economic values for the calculation of sheep selection indices. An important determinant of breeding objectives and selection indices is the percentage increase in the value of wool for each 1 8m reduction in fibre diameter, termed index percentage (IP). From 1950 to 1981 the appropriate IP value for fine (20 8m), medium (21 8m) and strong (23 8m) wool Merinos was 5%. From 1981 to 1993 the mean weekly IP values for fine, medium and strong wool Merinos were about 20, 15 and 8% respectively. The 5 year moving average IP values in 1993 for fine, medium and strong wool Merinos were 25, 20 and 8% respectively. The distributions of weekly wool prices and IP values are not normal and are positively skewed. Therefore, a safer, more conservative approach is to calculate the median weekly IP values for any period or to use median weekly wool prices to calculate IP values. The median weekly IP values for 1981-1993 were 20, 11 and 8% for fine, medium and strong Merino wools respectively. Thus recently there has been a larger relative premium for fibre fineness which could be a permanent trend. Selection efficiencies for clean fleece weight and fibre diameter in fine and strong wool Merinos are predicted to be at least 90% when 10% and 5% indices are used respectively. Selection efficiency in medium wool Merinos when a 5% index is used is only 79% if the 'true' IP is 15%, or 90% if the 'true' IP is 10%. The 10% and 5% indices are currently calculated and made available to the ram owners who participate respectively in the N.S.W. Merino fine and medium wool sire evaluation schemes. It is suggested that there is a case for using indices with higher fibre diameter premiums (i.e. 20% and 10% respectively), than those currently provided in the fine and medium wool schemes.

Effects of genotype and environment on wool production of Merinos at pasture at two locations in semi-arid tropical Queensland

The problem of low wool production in central- western and north- western Queensland led to a study of the relative wool production of different genotypes of Merino sheep in these 2 regions. A number of the bloodlines of sheep introduced to central western and north-western Queensland attained a higher mature liveweight (P&lt;0.01) and produced more wool (P&lt;0.05) than the locally bred sheep. Annual wool production was closely related to mature liveweight, and the strong wool South Australian Merinos were consistently the heaviest and produced the most wool. Ranking on fleece characteristics and liveweight was consistent for both locations. Under severe nutritional stress, the sheep introduced to north-western Queensland showed a significantly (P&lt;0.05) greater drop in tensile strength of their wool than locally bred sheep. There was a significant difference (P&lt;0.05) between productivity levels of the sheep at each location, with the environment in central-western Queensland being more suited to wool production. The results of this experiment suggest that some bloodlines of Merinos offer the potential to improve the wool production of sheep bred in central- western and northwestern Queensland; however, the effect of rearing environment may also be important.

The derivation of economic values in breeding programs for Australian Merino sheep with changing wool prices and flock production averages

The impact of fluctuating wool prices on setting economic values (EVs) in selection indices, e.g. WOOLPLAN, are studied by modelling genetic change in a flock following index selection, Operating under different wool price regimes. Because future price changes are difficult to predict, there is no guaranteed, optimal method of determining EVs. One possibility is the use of a moving regression of the last five years' wool prices (in real terms), rather than setting the index once, or every five years, or every year, based on current prices. The ratio (R) of clean wool price to micron premium is more important than actual prices. It is suggested that the default EVs used currently in WOOLPLAN are appropriate for strong wool Merino flocks. The choice and implications of EVs in other situations are discussed.

Food intake, growth and mature size in Australian Merino and Dorset horn sheep

ABSTRACTThe pattern of food intake as a function of age, and live weight as a function of food consumed was examined from soon after weaning to maturity in groups of fine and strong wool Merino rams and Dorset Horn rams and wethers. Each group, which initially comprised 20 sheep and from which individuals were removed for slaughter at approximately 6-kg increments in live weight, was fed a pelleted ration ad libitum for 98 and 77 weeks for the Merino and Dorset Horn groups respectively.The pattern of food intake was similar for all groups of sheep, in that food intake increased to a maximum at approximately 50 weeks of age and then declined with age with a regular oscillation superimposed on this curve. In all three groups of rams, but not in the Dorset Horn wethers, the oscillations in food intake were on an approximate annual cycle with a decrease in food intake in summer and an increase in winter.Estimated mature live weights for the strong and fine wool Merino rams were 120·5 and 97·6 kg, and for the Dorset Horn rams and wethers 108·6 and 101·4 kg. Variation between breeds in the level of food intake, food efficiency and consequently the pattern of growth, was largely a function of mature size. The Dorset Horn rams were slightly more efficient at converting food to live weight than the wethers.

The comparative productivity of five ewe breeds. 4. Growth and carcase characteristics of purebred and crossbred lambs

The growth to slaughter and carcase characteristics of purebred and crossbred lambs from five ewe breeds were compared in an experiment in 1971 and 1972 at Temora Agricultural Research Station. The ewe breeds were a Border Leicester x Merino fixed halfbred (BLM), Corriedale, Polwarth, a South Australian strong wool (SA Merino) and a medium wool Peppin strain of Merino. In each year, ewes of each breed were joined either to their own breed of ram or to Dorset Horn rams. The analysis used tested whether differences between ewe breeds in crossbred performance were halved compared with the differences between ewe breeds in purebred performances. The results supported this hypothesis for all characters measured. The largest breed effects on lamb performance were found for growth rate. Compared with the overall mean, the growth rates to weaning for purebred lambs were 118%,102%, 90%, 99% and 91% 10 for the BLM, Corriedale, Polwarth, SA Merino and Peppin Merino, respectively. The deviations from 100% for crossbred lambs were halved. Differences between breeds for carcase traits were estimated at the same carcase weight. South Australian Merino lambs had a lower dressing percentage than lambs from .the other breeds. Polwarths had the greatest depth of fat at the 12- 13th rib. Skins from Merino lambs had shorter staples and higher visual counts than skins from the other breeds. However, it was concluded that breed differences in carcase and skin characters, independent of carcase weight, were of little value in an economic comparison of the breeds for total productivity.

The comparative productivity of five ewe breeds. 1. Lamb growth and survival

An experiment was conducted at Temora Agricultural Research Station to compare birth weights, growth rates to weaning, and survival of lambs from five breeds. These data formed part of a larger study comparing the productivity of these breeds as possible dual-purpose ewe breeds. The breeds were a Border Leicester X Merino fixed halfbred (BLM), Corriedale, Polwarth, and a South Australian strong wool (S.A. Merino) and a medium wool Peppin strain of Merino. The descending order of ranking of the breeds on birth weight and growth rate to weaning was BLM, Corriedale, S.A. Merino, Polwarth and Peppin Merino. A significant breed x year interaction in pre-weaning growth rate was recorded, since the absolute differences between breeds increased as the overall mean growth rate increased. Breed means for the survival rate of single-born lambs ranged from 80.7 to 86.4 lambs weaned per 100 lambs born and they were not significantly different from each other. The mean survival rate of multipleborn lambs from the S.A. Merino and Polwarth breeds were 65.0 and 69.5 respectively, and these were significantly lower than the survival rate of multiples from the other breeds (76.8 to 80.4). Within breeds, birth weight was found to be positively related to survival at low birth weights but negatively related to survival at high body weights

The comparative productivity of five ewe breeds. 3. Adult ewe performance

Reproductive, wool and liveweight data on adult ewes from five breeds at Temora Agricultural Research Station between 1966 and 1972 were analyzed .The breeds were a Border Leicester x Merino fixed halfbred (BLM), Corriedale, Polwarth, a South Australian strong wool (S.A. Merino) and medium wool Peppin strain of Merino. Mean levels of reproductive performance were 1.22,0.96,0.85,0.78 and 0.88 lambs weaned per ewe joined for the BLM, Corriedale, Polwarth, S.A. Merino and Peppin Merino breeds, respectively. The superiority of the BLM breed was primarily due to a higher proportion of ewes bearing multiple lambs, of ewes lambing. Average greasy fleece weights for the breeds were 4.58, 5.67, 4.75, 6.1 5 and 4.95 kg, respectively. Pregnancy and lactation reduced fleece weight by 6.1 % and 3.3%, respectively. There was no additional effect of litter size on fleece weight. The liveweights of adult ewes prior to joining were 59.6, 54.8, 46.3, 49.0 and 42.7 kg for the BLM, Corriedale, Polwarth, S.A. Merino and Peppin Merino, respectively. The implications of this large variation in adult liveweight to the evaluation of the breeds were discussed.

The comparative productivity of five ewe breeds. 2. Hogget wool production

This paper contains information on the fleece characteristics of hogget ewes from five breeds in each of seven years at Temora Agricultural Research Station. Measurements of greasy fleece weight, clean scoured yield and the components of clean fleece weight were made on the following breeds: a Border Leicester x Merino fixed halfbred (BLM), Corriedale, Polwarth, a South Australian strong wool (S.A. Merino) and a medium wool Peppin strain of Merino. Average annual clean fleece weights were 3.53, 3.53, 3.04, 2.77 and 2.70 kg for the S.A. Merino, Corriedale, BLM, Peppin Merino and Polwarth breeds respectively. Average fibre diameters of these breeds were 23.1, 25.1, 27.2, 20.3 and 22.1 pm respectively. An interaction between breeds and years for clean fleece weight was associated with larger differences between the breeds in the years when environmental conditions favoured higher average clean fleece weights. Differences between breeds were large in all the components of clean fleece weight. Within breeds, the contribution of variation in follicle number to variation in clean wool weight was relatively greater in the Polwarth and Peppin Merino breeds than in the Corriedale and S.A. Merino breeds, with the BLM breed intermediate. The converse ranking applied to variation in fibre volume as a contributor to variation in clean wool weight within breeds.

A survey of moisture content in some greasy wool from New South Wales.

A study of fleece moisture content showed that it was not evenly distributed over the body of the sheep. The lower mid side of the fleece showed the highest average moisture content, while positions such as mid shoulder, lower shoulder, flank, and belly showed moisture contents above the mean value. The mid side and mid hindquarter positions showed means approximately equal to the average for the entire fleece. Positions more exposed to the air, such as upper shoulder, upper side, and upper hindquarter, showed lower amounts of moisture. Change in relative humidity during shearing affects slightly the initial moisture content of the wool. High-yielding wool shows a higher affinity for moisture. A strong wool strain of sheep had a significantly higher moisture content than medium and fine wool strains run together in the one environment. Wools of different origin in New South Wales on the showfloor of a wool store exhibited marked and statistically significant differences in moisture content both between and within districts. The variations within districts are greater than the variations between districts. Wool packed in bales, although stored in Sydney for a period of 6 or more weeks, had not reached equilibrium with the coastal atmosphere. Differences as large as 7 per cent. were found on the showfloor. Evidence collected in this study suggests that expert wool valuers and buyers cannot or do not take into consideration moisture content differences which are as large as 6 per cent. Although existing practice in commercial yield estimation apparently does not affect the wool merchants, individual growers selling wool grown, or shorn, or both grown and shorn in drier atmospheric conditions may be losing substantially.