Romanov is one of the most prolific breeds along with Finnsheep, Booroola Merino, Barbados Blackbelly and British Milk Sheep.

This breed started to be used in worldwide (1960’) in crossbreeding activities to take advantage of its
high ovulation rate, increased litter size and survivability of its offsprings. Romanov has been imported into 17 countries, in Europe, North America, South and North Africa, South America, Middle East. Romanov was first introduced Turkey via frozen embryos imported from Alberta, Canada in June, 2005. Ataturk University, Sheep Research Centre (A.U.S.R.C) where Romanov sheep has been widely studied in pure breeding, crossbreeding
and creation of several synthetic breeds.

Research & Results

The sheep industry competes against beef, pork, poultry, and fish for food dollars of consumers who have many choices of high-quality meats. To compete effectively, the industry needs to produce uniform, nutritious, lean lamb that satisfies the eating preferences of consumers and to improve reproductive efficiency and reduce labor requirements so that seed stock and commercial flocks are both practical and profitable under a range of production environments.  This challenge can be met by taking into account of advantage of breed diversity which is important aspect in any livestock breeding program, but is extremely critical in the sheep industry. For any trait affecting efficiency of meat production, there is useful genetic variation among breeds.  A good example is lambing rate, the number of lambs born per ewe lambing. Average lambing rates of breeds vary more than twofold, from perhaps 1.6 for mature Rambouillet ewes to about 3.7 for mature Romanov ewes.  To overcome the meat shortage in developing countries, indigenous sheep with low reproduction rate are advised to undergo crossbreeding with prolific breeds which will well adapt into the target region.  

Romanov is known as one of the most prolific breeds such as Finnsheep, Booroola Merino, Barbados Blackbelly and British Milk Sheep. This breed has been started (1960’) to be used in worldwide in crossbreeding activities to take advantage of its high ovulation rate, increased litter size and survivability of its offspring. The word "litter" is no longer used only for pigs, dogs and cats. After all, some Romanov ewes can produce more litter than some pigs can. Quadruplets, quintuplets and even sextuplets are common for a Romanov ewe. The North American record is a litter of seven live Romanov lambs. The record for the breed is nine! Genetically unique, the Romanov is a "pure gene" not a "cross" of other breeds. Romanov has been announced with great grazing ability (18-20 km) and longevity (10-12 years). When a Romanov is crossed with traditional breeds of sheep, a "hybrid" is produced. This hybrid advantage or "heterosis" affects rate of gain, lamb survival, fertility and litter size. The next shocker is the early sexual maturity. While most sheep producers struggle to get their ewe lambs to lamb by the time they are twelve months old, the Romanov ewe lambs are fertile and cycling by the time they are three months old. Unlike traditional sheep, which will breed only in the fall of the year, the Romanovs breed any month.

Romanov Worldwide

Romanov breed has been widely evaluated in numerous European, Middle Eastern, and North and South African countries beginning in the 1960’s.


The Romanov and Finn breeds have been used in the European countries in order to improve the reproduction traits of the local breeds (Espejo Diaz, 1989). Institut National de la Recherche Agronomique (I.N.R.A.) where Romanov sheep has been widely studied in pure breeding, crossbreeding. The creation of the INRA 401 sheep bloodline began in France in 1970, after a series of experiments crossing the Berrichon du Cher x Romanov which began in 1963 with the Romanov breed. Matings were carried out for several successive generations, between breeding stock of the same generation chosen in priority to maintain the origins represented in the foundation generation. In 1987, there were 15 000 purebred, 80 000 F1 and 21 000 I.N.R.A. 401 ewes. The INRA 401 is a highly productive ewe, with a 200 percent prolificacy, excellent out-of-season fertility, good milk production, and outstanding mothering ability. The F1 ewes have a high productivity, whatever the conditions (intensive or extensive) or the reproductive system (one lambing per year or three in 2 years) (Ricordeau, 1982).

There are various countries in Europe where Romanov has been used for the improvement of local breeds of sheep. Romanov has been recently used in Poland in the sheep prolificacy improvement program initiated in the 1990s. The National Research Institute of Animal Production was one of several research institutions carrying out research as part of this program. The objective of this research was to determine the effect of Romanov sheep inheritance on improvement of Polish Merino prolificacy. Research work was conducted at a sheep farm of the Institute's Experimental Station in Pawlowice from 1994 to 2001. It was noted that 25% Romanov (R1) breeding in the Polish Merino had a positive effect on all reproductive traits of the crossbreds. R1 ewe dams have been found superior to Polish Merino ewes in prolificacy by 42.1 percentage points, in fertility by 2.1 percentage points, in lamb rearing by 1.3 percentage points, and in reproductive performance by 27.6 percentage points on average (Sikora, 2003). The researches carried out in different countries (Borys and Osikowski, 1996; Osikowski and Borys, 1996; Young et al., 1996) has also shown favorable influence of the Romanov breed on reproductive performance (higher prolificacy, earlier reproductive maturity) and vitality of the lambs, but the crossbreds' slaughter performance was worse, especially during the live evaluation.
Romanov was used to create a composite breed called Gotland sheep. Gotland sheep (also known as Gotland Pelt Sheep) were first established on the large Baltic island of Gotland, off the east coast of Sweden. This breed has been obtained by crossing Karakul, Romanov and native landrace sheep. Goatland sheep was also taken to Australia for their elite fibre. Mature animals, shorn twice per year, can be expected to produce in excess of 7 kg of fleece annually. Australian Gotland sheep is not only known by their desired wool production traits but also high fertility, quick growing ability and easy handling.

Cross-breeding with both Finn sheep and Romanov has been practiced in several countries of the Mediterranean basin (Ricordeau et al., 1990). In Spain, Romanov has performed better than Finn sheep when mated to local ewes (Valls, 1983b). The Salz breed was developed by crossing Romanov rams of two strains with Rasa Aragonesa ewes in two flocks of 300 breeding ewes each (Fahmy, 1996). Salz ewes have showed good production potential in a system requiring improved prolificacy or accelerated lambing schedules. This new synthetic breed have been recorded with increased litter size (1.40 versus 1.71) compared to native breed. Authors (Maria and Ascaso, 1999) emphasized that crossing Romanov with low prolificacy, hardy native breeds can result in a substantial increase in productivity.

Altamura breed originated from Apulia a region in southeastern Italy has been crossed with Romanov to compare primiparous F1s performance with Romanov and Altamura breeds. Prolificacy have been increased from 1.25 to 1.76 for F1 and Atamura, respectively. Also lambs weaned per ewe was higher for F1 (1.51) compared to local breed (1.13) (Vicenti et al., 1993).

Leite Salvado et al., (1989) from Portugal have investigated opportunities to increase of meat production by increasing prolificacy by crossing Merino Branco ewes with Romanov. They found that prolificacy was higher for crossbreds (1.72 versus 1.24) than for Merino Branco ewes.
The Romanov breed was introduced into northern and southern Mediterranean countries has been reported with favourable results; however there is a depressive effect of heavy summer heat on male activity and female fertility. Composite lines have been created in Spain and Hungary (Ricordeau et al, 1990).

North America:

Romanov has been selected for obtaining optimal breed composition for easy-care hair breed by USDA and it was reported that varying levels of performance for reproductive efficiency (fertility, prolificacy, and maternal ability) and easy-care traits (adaptation, hardiness, parasite tolerance, and shedding of hair and wool) were created by mating Romanov ewes to Rambouillet, Dorset, Dorper, and Katahdin rams. Lupton et al., (2004) indicated that broader use of crossbred Romanov ewes would greatly increase the efficiency of commercial sheep production. Superior reproduction of Romanov-sired ewes was due to greater conception rate and prolificacy at each mating season and ewe age. Use of Romanov crossbred ewes would increase fertility during spring mating, an important constraint of the sheep industry (Leymaster et al., 2004). Increased utilization of the Romanov breed as a maternal contributor to a crossbreeding system can be implemented with minimal consequences in growth or carcass characteristics while increasing reproduction and fitness (Freking and Leymaster, 2004).

Canada, the pioneer for the sheep improvement programs in North America, has been conducting plenty of researches based on pure and cross breeding of Romanov sheep. Romanov breed in North America was reported high and generally comparable to that in Russia, France and other European countries (Fahmy, 1989). Romanov has been evaluated on every possible production trait such as reproductive and growing performance, carcass and wool quality.

Middle East:

Israil was one of the countries where genetic integration of dairy and mutton sheep production has been attempted by using Finn and Romanov (Gootwine et al., 1989). Romanov has been used mainly to increase prolificacy of Awassi sheep up to about 2.0 in Israil and crosses had only a marginal impact on the semi-intensive sheep industry in this country, mainly because of the preference for the traditional Awassi fat-tailed phenotype among the local breeders and consumers (Goot et al., 1980).

Egyptian sheep breeds are characterized by extended breeding seasons, high fertility, and low prolificacy. Currently in Egypt efforts are being made to intensify production systems, primarily through changing reproductive management and crossing native breeds with prolific breeds. Egypt Ministry of Agriculture is currently doing some crossing with Finn and Romanov to increase lambing rate of local breeds (Almahdy et al., 2000).


Romanov has been intensively used for increasing productivity of sheep raised in South Africa. The first Romanovs were imported to South Africa in 1963. Since then, Romanov sheep have grown to moderate numbers and the animals available today, are well adapted to local conditions. This breed is mainly promoted for use in crossbreeding programs with local breeds where ½ or ¼ first cross ewes are preferred. Dorper was one of the sheep in South Africa to be used for crossing with Romanov. Even though the mean age of different blood levels of Romanov X Dorper crosses did show significant differences on first breeding season estrus activity the percentage of animals completing 3 oestrous cycles was higher when Romanov blood level is increased from ¼ to ¾ (Greeff et al., 1994).

Romanov started to be used in crossbreeding programs in Turkey in 2004. Ataturk University, College of Agriculture, Depatment of Animal Science has conducted a serial of projects funded by University Research Foundation with 500,000.00 USD dollars. Pure Romanovs were obtained with frozen embryos imported from Alberta, Canada. Romanov rams were used in crossing with Turkish native sheep breeds and resulted with F1 crosses which have greater reproductive efficiency, growing performance and survivability rates.
Reproductive efficiency has a greater influence on the economic sustainability of commercial sheep production than does any other performance-related trait. An increasing interest in meat production forces to reconsider F1 breeding objectives in low prolific breed. Prolific breeds, like Finn, Romanov and Booroola are being used in the breeding program aiming at upgrading reproduction performance in maternal breeds. There are strong reasons for all above countries preferred Romanov instead of other prolific breeds. The reasons can be counted as greater conception rate and litter size, higher prolificy at each mating season, early breeding age for male and female, higher survival rate in pre and post natal period and growing performance in cross breeds.

Conception Rate and Litter Size:

Lambing frequency and litter size are important components of an efficient lamb production system (GabinÄa, 1989; Boujenane et al., 1991). Ewes sired by Romanov had a greater (80%) conception rate at 1 yr of age compared to Finnship (64%), Dorset (54%), Montedale (47%) and Texel (58%) sired ewes. Romanov-sired ewes can be expected to exceed performance of other breeds under management systems that expect first lambing at 1 yr of age. At 1 yr of age, Romanov sired ewes had the greatest number of lambs and the heaviest litter weights at weaning and at 20 wk of age. Ewes sired by Romanov rams were lightest at breeding and had the greatest conception rate, the greatest number of lambs at birth, at weaning, and at 20 wk of age when raised by the dam, and the heaviest litter weights at birth, weaning, and at 20 wk of age when raised by the dam. Finnsheep-sired ewes ranked next to Romanov-sired ewes for these traits (Leymaster et al., 2004).
Gallivan et al. (1993) reported that ewes from Romanov sires had a greater ovulation rate, produced and reared more lambs, and produced heavier lambs than did ewes from Finnsheep sires. Of the two prolific breeds, the greater longevity of Romanov-sired ewes (76.8%) provided further advantage relative to ewes by Finnsheep sires (70.5%). Superior performance of Romanov-sired ewes was due to greater conception rate and prolificacy at each mating season and ewe age, as well as greater longevity relative to ewes by Finnsheep, Texel, Dorset, and Montadale sires. Broader use of crossbred ewes incorporating Romanov germplasm would greatly increase the efficiency of commercial sheep production. It was shown previously that the prolific Romanov breed (mean ovulation rate = 3) has more antral follicles than the nonprolific breed such as Ile-de-France (mean ovulation rate = 1) (Chill et al., 1979).

Reproductive Performance at Different Mating Season:

Stanford et al., (1998) have studied the opportunity of using Romanov ewes to cross with terminal sires for out-of-season market lamb production. They concluded that breeding purebred Romanov ewes with terminal sires is an effective system for out-of-season market lamb production as the ewes show high (80-95%) lambing rates following April and May breedings while the comparatively low (60-80%) out-of-season lambing rates of the crossbred. The breeding season for the Romanov is longer and has been established to be between August and March (Fahmy, 1996). Ewes produced by Romanov sires had the greatest conception rate and prolificacy at each mating season.

Pre-Postnatal Survival:

While prolific breeds were reported with high incidence of low prenatal survival, Romanov is an exceptioanal with their higher rate (0.74) between ovulation rate and litter size (Ricordeau et al., 1976; Ricordeau et al., 1982 and Ricordeau et al., 1986). In a comparison of Finnish Landrace (FL) and Romanov as prolific breeds in a terminal sire crossbreeding system, prenatal survivability (Litter Size/Ovulation Rate×100) adjusted for ovulation rate, was repoted as greater for Romanov x Targhee than for FL x Targhee ewes (Gallivan et al., 1993). The markedly lower correlation between ova loss and ovulation rate in the Romanov breed (0.22) as compared to that in a number of crosses (0.58) with the Finnish Landrace breed involved in seven of them (varying from 1/8 to 7/8 upgrading; Fahmy, 1989). When compared in crossbreeding and purebreeding, the Romanov proved to be superior to the Finnish Landrace breed, in prenatal survivability (Ricordeau et al., 1990; Gallivan et al., 1993). Additionally, Romanov has been considered higher in uterine efficiency (the marginal increase in litter size as ovilation rate increases) compared to FL and Booroola Merino.

The other prolific breed carrying the FecB gene of Booroola origin have been used to increase flock prolificy but mortality rates for triplets tend to approach 30% (even with intense management) and with four or more lambs the mortality tends to be 50% and above (Willingham and Shelton, 1990). The net result is that litter sizes above two may not result in an increase in the lamb weight weaned. Freking et al., (2004) have noted differences between different ram breeds for ewe productivity with increased number born and improved survival of crossbred progeny to weaning for Romanov sired litters. Different breeds of ewes mated to Romanov rams have weaned more lambs than ewes mated to any of the other sire breeds. The authors concluded that ewes giving birth to Romanov-sired litters produced more lambs at birth with greater survival to weaning. Gallivan et al., (1993) observed similar tendency that Targhee ewes lambing to Romanov rams gave birth to .22 more lambs and had .15 more lambs alive at weaning compared to Finnish Landrace sired lambs. Overall conclusion from the study was that Romanov x Targhee ewes were superior to Finnish Landrance cross ewes with extra more weight of lamb at weaning by taking advantage of better rearing ability of Romanov sired ewes.

Breeding Age:

Highly prolific breeds tend to mature at an earlier age, as is the case for Romanov and Finnsheep (Fahmy, 1996; Maijala, 1996). The average earliest age of lambing for Romanov sheep was recorded as 233 days with 39 kg body weight at lambing. The percentage of animal lambed at about 8 months of age has been reported as 58% and 73% of these animals have lambed again at 16 months of age. Animals lambed twice or once at 16 months of age had similar body weight (53 kg). However litter size at birth and 70 days was lower in twice lambed ewes (2.50) compared to ewes (3.25) lambed once in 16 months and ewes lambed once raised 0.38 more lambs (Fahmy, 1990).
Gallivan et al., (1993) have compared Finnish Landrace and Romanov in a terminal-sire crossbreeding system and reported that Romanov x Targhee ewes has been observed with higher ovulation rate, younger at first estrus and lambing than Finnish Landrance crosses.

Growing Performance and Carcass Quality:

To overcome the meat shortage increasing reproduction rate is necessary. The new trend toward using prolific ewes and their crosses in sheep farming to improve productivity has increased choices among combinations of prolific and prolific x native lambs for market.
Borys and Osikowski (1996) evaluated fattening performance and slaughter value in two terminal crosses (Booroola Merino x Polish Merino or Romanov x Polish Merino). While ram lambs sired from Booroola Merino have showed a slower growth rate and poorer feed conversion, and a slightly poorer carcass quality and skin quality compared to Polish Merino lambs, Romanov sired lambs have showed better performance for these traits. In another study conducted by Gallivan et al., (1993) the fastest preweaning average daily gain was recorded in Romanov crosses relative to Finnsheep.

 Research on carcass and sensory quality of Romanov and their crosses (Theriez and Tissier, 1975; Sanudo and Sierra, 1982; Fahmy, 1986; Pommier et al., 1990) has indicated that this prolific breed produce acceptable market lambs. These studies also showed that excessive fat deposition occurs in the body cavity, whereas fat cover on the carcass is often inadequate to attain higher grades.
Considering age at slaughter as an indicator of overall growth rate, Fahmy et. al, (1992) reported that F1 lambs, produced by crossing DLS sheep Finnsheep (1/2)  and Romanov (1/2), were youngest (198 days), followed by Suffolklambs (204 days), whereas Finnsheep (264 days) and 1/2 Booroola Marino lambs (243 days) ranked last. Finnsheep and Romanov prolific breeds had a higher percentage of off-flavor than did a standard meat-type breed such as the Suffolkbreed. Authors conducted this study emphasized that wide-scale use of prolific breeds and their crosses to increase productivity of sheep will not have an adverse effect on quality of the carcasses or the meat available for consumers.

Wool Characteristics:

Many crossbreeding experiments have been conducted to estimate genetic effects of breeds of sheep. Typically (e.g., Wolf et al., 1980; Kempster et al., 1987), but not always (e.g., Snowder et al., 1997), increased lamb pproduction has been the primary objective of such experiments. Nevertheless, comprehensive evaluation requires that other factors, such as wool production and quality, also be considered.
Lupton et al., (2004) have evaluated wool characteristic of Romanov and Finnsheep and reported that both of these prolific breeds have been announced to produce offspring having the finest wool compared to Montadale, Dorset, and Texel. This order of increasing fiber diameter in F1 ewes was the same as for purebred rams of the sire breeds. In the current wool market, the micrometer range (23 to 30 m) of the wool produced by the F1 Romanov and Finnsheep ewes ensures that income from wool will be only a small portion (1 to 5%) of overall income from sheep production.

What makes Romanov unique in crossbreeding activities?

In cross-breeding systems, the use of F1 ewes requires simultaneous breeding of purebred and F1 offspring, a situation that requires an intensification of management and increases in cost of production (Sierra, 1985; Galal et al., 1993). This is probably the main reason why commercial sheep farmers are increasingly interested in the use of synthetic lines instead of first crosses. Generally, F1 animals tend to be better than subsequent inter se crosses. While there are numerous reports on the performance of F2 animals, empirical results on F3+ generations are limited. Due to recombination loss, this heterotic superiority in the F1 animals is expected to break down in subsequent generations, which is confirmed by findings of Syrstad (1989), who reported considerable declines for all relevant dairy traits when comparing the F2 with the F1 generation. Like in other farm animal species, F1 animals are reported to show the highest heterosis, which is lost in subsequent inter se matings. Boujenane and Chafik (1994) reported experiences with D'Man × Sardi crosses in Morocco, where an almost 20% heterosis for number of lambs born in the F1 is reduced to 13% and 5% in the F2 and F3, respectively. In sheep, repeated inter se matings with selection to create `synthetic' breeds have been exercised, e.g. in India (Avikalin breed) or South Africa (Dorper breed). Again, the development of a new breed or establishing and maintaining a complex mating scheme (such as crisscross or three breed rotation) requires considerable infrastructure and has a high risk of failure. Additionally, populations go through a genetic bottleneck in the formation of synthetics, with a high risk of loss of genes of potential future importance (Simianer, 2000). Ricordeau et al, (1990) indicated that the F1 Romanov crossbred ewes have a high productivity, whatever the conditions (intensive or extensive) or the reproductive system (one lambing per year or three in 2 years). The absence of regression of performance from F1 to F4 has led to the creation of a composite line, the I.N.R.A. The heterosis effect was reported high for fertility in ewe lambs and favourable for lamb viability.

A maternal effect, in genetics, is the phenomena where the genotype of a mother is expressed in the phenotype of its offspring, unaltered by paternal genetic influence. This is usually attributed to maternally produced molecules, such as mRNAs, that are deposited in the egg cell. Maternal effect genes often affect early developmental processes such as axis formation. This term may also be used to describe maternal inheritance, in which some aspect of an offspring's genotype is inherited solely from the mother. This is often attributed to maternal inheritance of mitochondria or plastids, which each contain their own genome. This phenomenon is distinct from the first phenomenon because in maternal inheritance the individual's phenotype reflects its own genotype, not necessarily the genotype of its parent. Maternal direct effect of the Romanov was higher (P<0.05) than that of the Finnsheep in lamb weights at birth and on day 50 (Gallivan et al.,1993). An important maternal effect has been also observed by  Maria et al., (1993) for birth weight, weaning weight  and daily gain for the periods birth to weaning in Romanov lambs. 

In the sheep, the Callipyge phenotype is a muscular hypertrophy that is subject to a parent-of-origin effect. The phenotype is only present in individuals that have a single mutated allele of the Callipyge (Clpg) locus inherited from the father. Fahmy et al., (1999) has investigated callipyge phenotype born to Romanov purebred and crossbred (Suffolk x Romanov) ewes. They reported that 50% of lambs expressed the callipyge phenotype (CP). The Cg lambs have been reported as younger to reach slaughter weight and had higher dressing proportion. They also had more leg, less loin and less shoulder than the normal phenotype lambs. Besides Cg lambs have been found more favorable in terms of more lean, less fat, larger loin-eye area, less backfat and less internal fat.

Inferiority in Romanov:

Romanov breed is noted for early sexual maturity (Fahmy, 1990), a long breeding season (Ricordeau et al., 1990) and high prolificacy (Hackett and Wolynetz, 1985; Ricordeau et al., 1990). However, these reproductive advantages are mitigated by reduced growth rate (Fahmy et al., 1992) and carcass quality (Stanford et al., 1997) as compared to traditional meat-type breeds. Ricordeau et al, (1990) also agreed with others about lambs sired Romanov have had a high growth rate, but a low carcass and meat quality.

 In an early sexual maturing, prolific breed such as the Romanov has been reported with inferior carcass quality. Despite the popularity of Romanov sheep for their superior prolificacy (imported into over 17 countries; Fahmy, 1996), surprisingly few research studies have been conducted to characterize the composition and quality of their carcasses. Most of the work reported in the literature comes from Russia where pure Romanovs were compared with Romanov-crossed lambs for traits related to growth and dressing percentage (V&ii and Gushchin, 1985; Al-Lakham, 1990).

In these Russian studies, the inferior quality of Romanov male lamb carcasses resulting from the heavier anterior proportion of the carcass has not been addressed. Fahmy (1997) reported that inferior quality is manifested by heavier weight of the shoulder and lighter weights of the most valuable cuts of the carcass of the Romanov lambs. Higher concentration of testosterone in Romanov lambs was correlated proportion of loin (positively) and leg (negatively).

As Romanov lambs seem to have similar carcass proportions to other breeds at birth, the developmental changes leading to Romanov carcass inferiority must occur during the growing period. In their reviews of French research with Romanov, Ricordeau et al. (1988, 1990) referred to the inferior quality of the Romanov carcass but indicated that no work has been done in France to find a solution. The work by Fahmy (1992) showed that carcasses of castrated and female Romanov lambs approached in carcass quality those from other breeds.
In one particular French report by Teyssier and Prud’hon (1982), the entire carcasses of Romanov and Romanov crosses ranging in age from 25 to 150 days, were dissected into separate muscles and each muscle was weighed. The results showed that in crosses there was a slightly favourable shift in size of muscles as compared to the pure Romanov.

Research conducted at the Lennoxville Research Centre confirmed the poorer carcasses of the Romanov males compared with females (Pommier et al., 1989) and to other genotypes (Fahmy et al., 1992). Other data showed that castrating Romanov lambs decreased the proportion of shoulder and increased that of leg wholesale cuts of their carcass (Fahmy, 1992). 


Assuming that slaughter lambs production is the main aim of sheep husbandry, it is most important to improve reproductive performance in maternal flock, especially as the present level of fecundity is not sufficient to secure profitability of sheep farms. The program on prolificacy improvement in national sheep population should be introduced to improve in size of litters by upgrading local breeds through crossbreeding with prolific breeds such as Romanov.

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