Maataloustieteellinen A ikakauskirja Vol. 60: 473—480, 1988 Finnsheep and their crosses under subtropical conditions A. M. ABOUL-NAGA Animal Production Research Institute, Ministry of Agriculture, Dokki, Cairo Abstract. Finnsheep (F) have been introduced to eight countries in the subtropical Near East region over the last two decades. Those trials aiming at breeding pure F under the sub- tropical conditions were generally not successful. Pure F faced problems of adaptability to the subtropical environmental conditions, however, bad management and some health problems (especially Pneumonia) contributed significantly to the failure of some trials. On the other hand, crossbreeding trials with F in the region were generally successful. F-crosses proved to be well adapted to heat stress and exposure to solar radiation compared with the local breeds. Number of lambs born/ewe lambed was improved in F-crosses, as com- pared to local breeds, by 18—75 % in the first cross and 10—38 % in the 1/4 F. F-crossbred ewes showed encouraging results in their ability to breed more than once/year, especially those with lower F-blood (1/4F). Number of lambs born/ewe/year in accelerated lambing systems ranged from 1.91 to 2.72 in the first cross and from 1.67 to 2.18 in 1/4 F either in experimental farms or at the producers. Crossing fat tail sheep with F substantially decreased fat in the tail of the crossbreeds, while it increased significantly internal fat and total fat percentage in the carcass. Index words: Finnsheep, subtropics, crossbreeding, adaptation, fertility, prolificacy, sexual maturity, growth, carcass Introduction Lamb production is an important activity in the subtropical Near East (NE) region as a main source of meat and a major source of income for good part of the population. Tri- als for improving lamb production from lo- cal sheep involving the introduction of tem- perate breeds have been widely made for a long time in the region, including recently Finnsheep (F). Over the last two decades, eight NE coun- tries have imported F sheep, mainly to cross it with local sheep to improve prolificacy, but purebred F was sometimes raised under the subtropical conditions. According to the Finn- ish Sheep Breeders Association the first im- portation of F sheep from Finland to the region was in 1969 by a private breeder to Al- geria (25 ewes + 2 rams). It was followed in 1970 by successive batches of rams, and some ewes, to Egypt and Israel (3). Single importa- tion of small flocks to each of Cyprus, Leba- non and Iran was carried out early in the 473 JOURNAL OF AGRICULTURAL SCIENCE IN FINLAND https://www.c-info.fi/en/info/?token=hUK73va43jxSiG9e.PuXxqRgfpO1UX0HKorky-w.rLG8EJhUQCDOabHpB53_BxgoRM5oZfexSa5nRFNO1IARTS_HI50mjmG7wtwB2tEoI7SdY9ksl662YIUDDXUxak4kHlcP_8MlDbd-1UIn_hlC7mGyBkFCv9JczVUtSS2TmkAuvi5QHROVDU8lHQwCH-0hEiYGGrbPIcAeW7EE seventies. The largest importations were those to Libya and Iraq where each country import- ed hundreds of F ewes plus some rams. Furthermore, some F sheep were introduced to the region from second country as theram batches imported to Egypt from UK and USA and the flock imported to Iraq from Yugos- lavia. Breeding plans and objectives Table (1) summarizes breeding plans and objectives of eight trials executed in six NE countries. Those of Algeria and Iran could not be traced as they were carried out by private breeders. The most significant trials accord- ing to the number of animals involved, dura- tion and available information are those of EMOA (Egypt) and lARO (Israel). Those of NASC (Egypt), CMOA (Cyprus), AUB (Le- banon) and IFAO (Iraq) were smaller in scale and few reports are available on them. The Libyan trial followed by IMOA (Iraq) were the biggest as far as number of imported animals is concerned. However, they were ter- minated after few years with no reports. In- formation was available only through per- sonal communication. Two objectives could be postulated among different trials, the main one is crossing the imported F rams to the local ewes to improve their prolificacy. After the Ist cross, cross- breeding is continued toward higher or lower grades, or in some cases utilized the Ist cross as dam line for fat lamb production and mate them to sires from mutton breeds. The other objective, either alone or along with the first one, was to breed the purebred F sheep un- der the prevailing subtropical conditions. Performance of purebred Finn Adaptation to subtropical conditions F were reported by El-Sheikh et al. (10) to be the least tolerant to heat stress and direct solar radiation under the Egyptian subtropi- cal conditions compared to three local breeds, followed by the Suffolk, then Ile-de-France. An interesting trial was carried out by EMOA to compare the performance ofF ewes imported to Egypt with their half-sibs raised in Finland. Egypt group was significantly (Pc.ol) of higher rectal temperature and pulse rate than their half-sibs in Finland all the year round (1). Their respiration rate in the summer was almost double that of the Fin- land group. The response of F ewes to heat and exercise stress was also investigated in comparison with the local Egyptian sheep and their crosses under subtropical condition. Their physiological and performance responses were dramatically high (12). On the other hand, F-crosses proved to be more adapted to the prevailing subtropical condi- tion. Their response to heat and exercise stress was closer to the local than to the F. Those of 1/4 F were almost similar to the local. Purebred F sheep imported from Yugosla- via to Iraq were reported to be badly affected by theprevailing subtropical environment and hygenic conditions (H. Karam, personal communication). The other flock imported later from Finland suffered from health problems (especially Pneumonia) and non- adaptability to the environmental conditions (F. El-Dessouky, personal communication). The situation in Libya was worse, soon af- ter arrival of the F flock it faced many difficulties, mainly because of bad manage- ment. The big flock (500 heads) diminished drastically and the trial was completely termi- nated within two years (H. Karam, personal communication). Reproductive performance Reproductive performance ofF ewes was also affected under the subtropical conditions. Their fertility was not satisfactory in Cyprus (Hadjibanayiotou, personal communication) and they performed the poorest among differ- ent breed groups studied in the EMOA trial which involved two local breeds and differ- ent F crosses (5). On the other hand, F sheep were able to maintain their high prolificacy, 474 Table 1. Breeding plans for different NE trials with Finnsheep. Country and Organization Started F sheep Breeding plan References imported Ministry of Agricul- 1970 40 M, 24 F xwith 2 local breeds -1/4 F, Aboul-Naga (1987), ture, Egypt (EMOA) + BM* inter se mating for synthetic. Aboul-Naga (1988) Agriculture Research 1970 23 M xwith Merino and Awassi for Goot (1975) Org., Israel (1ARO) intensive lamb production. Eyal et al (1984) National Academy of 1972 10M+10M* xwith 3 local breeds - 1/2 F Zahed (1988) Sc, Egypt (ENAS) Suf. or Ile-de-France Ministry of Agric. & 1972 6M,22 F Pure F and xwith 2 local breed Agroti (1976) Nat. Reso., Cyprus group —l/2 Fx lle-de-France (CMOA) American Univ. Bei- 1974 4 M, 7 F x Awassi and Texel A.U.B. (1982) rut, Lebanon (AUB) FAO, Iraq (FIRQ) 1973 5 M, 25 F* Pure F H. Karam (P. Comm.) Ministry of Agricul- 1979 15 M, 175 F Pure F and xwith Hamadani F. Dessouki ture, Iraq (IMOA) native sheep (P. Comm.) Agriculture Research 1979 50 M, 450 F pure F. H. Karam Coun. Libya (LARC) (P. Comm.) * imported from second country other than Finland number of lambs born/ewe lambed was 2.43 in EMOA trial and 2.3 in Cyprus. These figures are comparable well with the figures reported by Maijala (1984) under temperate conditions. Their lamb losses, however, were so high in both trials and ended by figures of 1.7 and 1.1 for lamb weaned/ewe lambed in the two trials. One of the important findings in the EMOA trial is the mild seasonal fluctuation in the se- men characteristics of the pure F rams, un- der the prevailing subtropical conditions. These mean that they can be used successive- ly at any time of year, which is important for accelerated lambing systems. However, difficulties of the pure F rams to mate with the fat-tailed ewes were frequently reported in different trials. AI, and in some cases dock- ing of the fat-tail, was used to come over this problem. Meanwhile, training the F rams on hand-mating with the fat-tailed ewes seems to be easy task in the EMOA trail. When F ewes were mated each 8 months, their fertility was good in January mating sea- son compared to the local breeds (70 %), but less in September (54 %) and only few ewes were mated in May (5). These figures are even less than the 60 % reported by Maijala and Österberg (18) as an average out-of-season conception rate for F sheep in Finland and other temperature countries. Performance of Finn crosses A) Reproductive Performance Prolificacy. Generally, F-crosses proved to be of higher prolificacy than the local breeds in different crossbreeding trials carried out in the NE. Improvement of prolificacy of the first crosses over the local breeds ranged from 18 to 75 % (Table 2). A rough mean for reported superiority is 40 %, which is higher than 31 % reported by Maijala (16) for the Ist crosses with temperate breeds. Results of other crosses rather than the first cross were reported in the EMOA and lARO trials. They showed that 1/4 F crosses were also of higher prolificacy than the locals but less than that of the Ist cross. Percentage of improvement over the corresponding local breeds ranged from 10to 38 % with an aver- age of 24 %, (versus 11 % for 1/4 F crosses with temperate breeds; (16). The Israeli trial involved some 3/4 F ewes, their prolificacy was 76 % more than the local. 475 Table 2. Reproductive performance of F-crosses in the NE under accelerated lambing systems. Genotype No. of EL/EE* LB/EL L/yr LB/EE/yr records EMOA (mating each 8 months, Sept., May and Jan.). Finn (F) 46 .52 2.43 .78 1.89 Rähmäni (R) 1512 .72 1.31 1.08 1.38 FR 743 .77 1.68 1.16 1.91 1/4F3/4R 941 .80 1.43 1.20 1.67 (1/4F3/4R) 2 741 .76 1.40 1.14 1.59 Ossimi (O) 613 .68 1.22 1.02 1.21 FO 382 .75 1.52 1.13 1.67 1/4F3/40 545 .76 1.38 1.14 1.52 (1/4F3/40)2 66 .95 1.42 1.43 1.89 lARO (in season and out of season matings with hormonal treatment) Merino (M) 382 .79 2.00 1.17 2.35 FM 434 .76 1.84 1.24 2.34 FA (Awassi) 365 .84 1.99 1.45 2.90 FA 266 .84 1.65 1.36 2.31 1/4F3/4M 77 .82 1.56 1.35 2.18 3/4FI/4A 67 .80 1.96 1.43 2.96 1/2 Assaf- -1/4FI/4A 102 .80 1.51 1.39 1.66 ENAS (mating each 4 months) Ossimi (O) 2545 .52 1.07 0.95 .83 Rähmäni (R) 1951 .41 1.10 1.04 .68 Barki (B) 1903 .40 1.07 1.02 .64 FR 33 .49 1.30 1.00 .96 FB 78 .52 1.25 1.19 .98 FO 68 .55 1.46 1.04 1.20 Cyprus (lambing twice a year) Chios (C) 53 2.13 1.20 FC 8 2.88 1.20 * EL: ewe lambed, EE: ewe exposed, LB: lambs born, L: lambing Improvement of prolificacy in the F cross- es with subtropical breeds is less than that ex- pected assuming linear increase in prolificacy with the proportion of F blood, especially in the Ist cross and higher F crosses. The linear slope of improving prolificacy with increas- ing F genes found in the temperate crosses (17) is not clearly justified in the subtropical F crosses. Failure of ova implantation or early embryonic losses in such high fecundity cross- es under the subtropical condition may con- tribute to these discrepancies. Inter-se mating of the Ist F crosses (IARO) or 1/4F (EMOA) does not seem to affect the prolificacy of the produced ewes (Table 2). Although it is still too early to judge the pos- sibility of establishing synthetics of high fecundity and well adapted to subtropical con- ditions in the region, yet the results are en- couraging. Fertility. When F crosses were mated once yearly, fertility was generally less than that of the locals. Meanwhile, most of the NE trials applied some sort of accelerated lambing sys- tem for the F crosses to utilize the ability in- herited from their subtropical parents to breed more than once/year (Table 2). Number of lambings/year (L/Yr) averaged 1.18 for EMOA, 1.23 for IRAQ, 1.08 for ENAS and 1.2 for the CMOA trials (Table 2). The more frequent lambing reported by IARO resulted from the use of hormonal treatment, whereas small number of F cross ewes were involved in the ENAS trial. An overall figure 476 of 1.2L/Yr can be reported in this aspect, vs. 1.3 reported for different subtropical breeds (2). Seasonal variation in reproductive perfor- mance and sexualactivity. Although F cross- es showed good ability to breed under acceler- ated lambing systems, yet seasonal variation in their reproductive performance was clear- ly noted in each of these trials. Seasonal differences in number of ewes lambed/ ewes exposed (EL/EE) or lambs born/ewes lambed (LB/EL) between autumn and winter (in sea- son) and spring and summer (out of season) were substantial in the EMOA and lARO tri- als and significant in ENAS (Table 3). Seasonal differences in LB/EE were 39.5 and 39.2 % in the first two trials, respectively. However, 1/4 F ewes in the EMOA trial showed less seasonal variation in their fertili- ty than the Ist cross, while it sustained seasonal variation in their prolificacy similar to other F crosses. Aboul-Naga et al. (5) speculated that high ovarian activity, including high ovu- lation rate, seems to be limited to the normal breeding season (fall), while during the prolongation of the breeding season, result- ing from crossing with subtropical breeds, ovulation rates are maintained at lower levels. The low seasonal variation in the fertility of 1/4 F cross ewes is in agreement with their consistent oestrous activity around the year even better than the local breeds (5). The 1/2 F ewes in the lARO trial showed oestrous ac- tivity similar to that of their local parent (7). Both trials, however, reported ovarian ac- tivity during the anoestrous period of the F crosses as detected by the hormonal profile. This may explain the relatively high fertility results obtained out-of-season, by hormonal treatment in the lARO or by the ram introduc- tion in the EMOA trials. On farm trials. EMOA carried out on farm trials to test the performance of 1/4 F-cross- es under the breeders’ and small farmers’ con- ditions versus the local sheep at some villages in the Nile Delta area. The preliminary results were reported by Aboul-Naga (3). With the rams run with the ewes all the year round, lambing intervals averaged 9.4 months for Ist lambing and 8.5 months for adult ewes. An- nual number of lambs born/ewe averaged 1.60 and 2.2 for the ewe groups respectively, and number of lambs weaned annually were 1.5 and 2.09, respectively. These are rather satisfactory figures for lamb production un- der these conditions. Some of lARO results were also reported from commercial flocks, especially those of crosses other than the Ist cross. Results were as satisfactory as, or even better than, at the experimental farm (14). Sexual maturity. One of the reported characteristics of the F sheep is their early maturity, ewe lambs usually mated at 7—B months of age (18). In lARO, 1/2F ewe lambs tend to lamb earlier than the locals, especial- ly for the Awassi crosses, where age at Ist lambing were 404 days for the Ist cross, 359 days for back-cross ewe lambs versus 457 days for Awassi. Furthermore, conception rate at first mating was substantially higher for F- cross ewes. Season of birth showed some ef- fect on age at first lambing. In EMOA, age at puberty was attained de- lectably earlier in the F crosses (6.5 —7.5 months versus 8 months for the local). The 1/4 F ewes lambs attained puberty about 2 weeks earlier than the Ist cross (Aboul-Naga, unbublished data). Also F-cross ram lambs of AUB reached puberty early at 6—7 months of age. AUB (8) stated that genes of early sexual maturity are transmitted through crossing with F sheep. B) Lamb and Carcass Performance: Lamb losses. Lamb losses during the Ist 4 months of their life is an important criterion under the relatively harsh subtropical condi- tions especially for highly fecund sheep as the F crosses. Lamb losses were generally low for most trials, ranging from 4 to 12 %. In IARO it averaged 22 % under experimental farm conditions, with similar loss rates for singles and twins and much higher for triplets or 477 Table 3. Seasonal variation in reproductive performance of F-crosses in the NE. Season of No. EL/EE LB/EE LB/EL mating EMOA September 1743 .75 ±.02 1.23 + .04 1.70 ±.03 January 1552 .82+ .03 1.10 ±.04 1.40 ±.30 May 222? .69 ±.03 .93+ .04 1.42 ±.04 Seasonal differences ** *** *•* IARO Nov.-Feb. 690 .89+ .09 1.74 ±.30 1.95 ±.21 May-Sept. 362 .79 ±.lB 1.25 ±.37 1.79 ±.29 Seasonal differences ** ** * ENAS Jan. -Feb. 1916 .42 ±.03 1.10 ±.Ol May-June 2239 .27 ±.03 1.11 ±.Ol Sept.-Oct. 2811 .53+ .03 1.15 ±.Ol Seasonal differences ** * * significant at 5 %, ** significant at 1 %, significant at .1 %. quadruplets. Lamb losses were higher in Meri- no than in Awassi crosses (14). Lamb losses were much less in the commercial flocks to average 11.5 %, the on-farm trials of EMOA showed also mild mortality rates of B—l 2 % up to weaning. Growth andfattening performance. Gener- ally, birth weight of F crosses was either slight- ly higher than or close to that of local lambs. Higher frequency of multiple births in the F crosses may contribute to these findings. Growth rates during suckling were generally higher than that of the locals (19, 14, Aboul- Naga, unpublished data). Milk production from F-cross ewes was comparable to that of the native sheep but less than some other sub- tropical breeds known to be of good milk production, i.e. Awassi and Chios (lARO and CMOA). Postweaning performance of F crosses varied greatly in different trials. It ranged from being less than the local breeds with daily gain of 164 g (ENAS) to high as 247—257 g/day (9). Other trials fall in between these findings. From another point of view, differ- ent trials showed significantly earlier slaugh- ter age of F crosses (15, 11). Carcass composition. The most noticeable feature in the carcass composition of F cross- es is the drastic reduction in the fat tail com- pared to the local sheep disproportionate to the F blood (Table 4), which represent lower marketability for these crosses in the region, especially for the Ist cross or higher F cross- es. On the other hand, F crosses showed sig- nificantly higher carcass fat percentage and less lean percentage than local breeds. Fat- tailed subtropical sheep breeds are known to have lean carcasses (aside from the fat tail), on the other hand, one of the main inferiori- ty of the F carcasses is their less muscularity (18). Using terminal sires on F carcasses for fat lamb production, i.e. Suffolk cross in EMOA and Suffolk or Assaf in lARO and Ile- de-France in CMOA, does not seem to have favourable results in improving carcass com- position of the produced lambs (15, 11, 6). General conclusions 1. Raising purebred F sheep cannot be recommended under subtropical conditions, while their crosses, especially the Ist and low- 478 3 Table 4. Fattening and carcass performance of F-crosses in the NE, Breed No. Daily Slau- Slau- Car- Inter- Tail Fat Lean gain ghter ghter cass nal wt. % % wt. age wt. fat (kg) (kg.) (day) (kg) (kg)* EMOA Ossimi (O) 18 181 27.9 154 12.3 0.64 1.2 12.0 66.6 Rähmäni (R) 15 179 38.1 154 14.3 0.44 1.2 11.0 68.1 1/4F3/40 13 203 32.8 154 14.5 0.54 0.4 21.1 59.1 1/4F3/4R 24 196 32.7 154 14.5 0.50 0.6 20.0 59.0 ScXl/4F 3/40 21 196 32.5 13.7 0.75 0.4 20.2 61.4 ScX 1/2F 1/20 15 190 32.7 14.0 0.65 0.2 23.7 58.8 IARO Awassi (A) 7 263 51.1 263 25.0 1.45 5.8 38.5** 47.5 Merino (M) 33 300 56.3 300 29.6 1.20 30.2 55.7 FM 8 143 45.3 143 23.5 1.74 0.1 36.6 48.7 FA 11 143 45.3 145 22.3 1.79 0.4 37.6 47.7 AsxFM 9 139 46.2 139 23.3 1.87 0.2 33.7 50.7 AsxFA 4 141 45.8 141 23.3 1.23 0.7 37.4 48.9 * Kidney + gut fat. ** 1/2 Carcasses dissection included the tail. Sc : Suffolk cross, As : Assaf. er F crosses proved to be fairly well adapted to the subtropical conditions and can be uti- lized successfully to improve lamb production from local sheep. 2. Annual fecundity rate is a better indi- cator than prolificacy as it involves their abil- ity to breed more than once/year, to be able to measure up to local ewes in that regard. High prolific sheep may not be the best sheep under subtropical conditions. Moderately pro- lific ewes, as the low F crosses, and able to produce more than once per year, would suit better to the prevailing subtropical conditions. 3. F crosses showed substantial improve- ment in the prolificacy over the local breeds. Their performance, however, is less than ex- pected according to additive model, especial- ly for the Ist and higher F crosses. 4. Lamb performance of F crosses were generally satisfactory. They showed drastic decrease in their fat tail as compared to their local parents, however, their carcasses had higher fat content and were less lean than the local sheep. References I. Aboul-Ela, M.8., A.M. Aboul-Naoa, T.H. Shala- by, and K. Maijala, (1987). 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