Pre-weaning growth, carcass traits and sensory evaluation of
Corriedale, Corriedale
Pampinta and Pampinta lambs
V.H. Suarez
a,*, M.R. Busetti
a, C.A. Garriz
b, M.M. Gallinger
b, F.J. Babinec
a aEstacioÂn Experimental Agropecuaria Anguil, Instituto Nacional de TecnologõÂa Agropecuaria, CC 11, 6326 Anguil, La Pampa, Argentina bInstituto de TecnologõÂa de Alimentos, Centro de Investigaciones en Ciencias Veterinarias, Inst ituto Nacional de Tecnologia Agropecuaria,CC 77, 1708 MoroÂn, Buenos Aires, Argentina
Accepted 17 August 1999
Abstract
Birth weight (BW), weaning weight (WW), preweaning weight gain (PWG), carcass traits and sensory evaluation of meat of Corriedale (C), Pampinta (P) and their Fl crossbred (PC) lambs were studied from 1991 to 1993 at the Agricultural Experimental Station of Anguil (La Pampa, Argentina). Each year the trial involved an average of 35 C, 43 P and 36 PC. Data were analyzed for year, genotype, sex and birth type and their interactions as ®xed effects and birth weight and lamb age as covariables. The effects of genotype, sex, age and birth type were generally signi®cant (P< 0.05). P lambs had the heaviest (P< 0.03) BW (4.75 vs 4.26 kg for C and 4.30 kg for PC). Means for WW (33.4 kg) and PWG (295 g) of P were higher than those for C (24.6 kg and 218 g) and PC (27.7 kg and 245 g). Means for the latter genotype were signi®cantly higher than those for C. Carcass analysis showed smaller (P< 0.05) total fat and higher (P< 0.05) muscle percentages in P and PC lambs compared to C. No differences were detected in sensory evaluation between genotypes. Meat from the three groups had a slightly intense ¯avor, was rather juicy, tender and practically without connective tissues. These results suggest that utilization of P genotype may be effective to produce early ®nished lean lambs.#2000 Elsevier Science B.V. All rights reserved.
Keywords:Pampinta lambs; Crosses; Pre-weaning growth; Carcass traits; Meat quality
1. Introduction
The economic constraints of raising sheep solely for wool production, have resulted in a decline in the national population and economic importance of sheep in Argentina. A the present time, in the Pam-peana Region, most of the owners maintain ¯ocks of 100±200 wool-type crossbred ewes, Corriedale being
the principal breed. Currently, the main purpose of these ¯ocks is to produce meat for domestic consump-tion and the excess sold in local markets.
In spite of the poor management of these ¯ocks, producers value carcass yield and meat quality of lambs from those ¯ocks. Therefore, they choose to breed their ewes with rams from meat-type breeds, such as Karakul and Pampinta to increase lamb size and carcass leanness.
The Pampinta breed was developed by backcrossing local Corriedale ewes with imported East Friesian *Corresponding author. Tel: 54-954-95054; fax: 54-954-33163.
E-mail address: vsuarez@anguil.inta.gov.ar (V.H. Suarez).
(Ostfriesisches Milchshaf) milk type rams (Medrano, 1975). East Friesian sheep were chosen to improve proli®cacy and maternal ability of local ¯ocks (Fla-mant and Ricordeau, 1969). After 12 years of selection the Pampinta breed (3/4 Friesian 1/4 Corriedale) was established and is presently used in crossbreeding to increase meat and milk production.The objective of the current study was to compare lamb growth, carcass traits and meat characteristics of Pampinta and Corriedale breeds and their Pampinta Corriedale cross.
2. Material and methods
The study was conducted at Anguil Agricultural Experimental Station (La Pampa, Argentina) from 1991 to 1993. Each year, before the mating period (March), 3 groups of 3±5 year old ewes were separated at random. Different ewes were used each year. Three Corriedale (C) males were mated to 50 C ewes (group C); and three Pampinta (P) males were mated to 50 C (Group PC) and 50 P (Group P) ewes. Ewes were exposed to rams in March, to lamb in August and wean in December. In 1991 and 1992 large meat-type C rams (mean live weight 110 kg) were used whereas in 1993 wool-type C rams (mean 97 kg) were used. The mean live weight of P rams was 104.35.4 kg. Ewes were weighed in March, May, September and Decem-ber. Ewe groups grazed together on the same paddocks from mating to weaning.
Sex, birth type and lamb weight, were recorded within 24 h of birth. The number of pure breed and crossbred progeny varied from year to year, averaging 35 (C), 36 (PC) and 43 (P) lambs.
Lambs were weighed at weaning, when they aver-aged 92 days of age. Preweaning growth was calcu-lated as the average daily weight gain from birth to weaning. Arti®cially reared lambs, generally from triple births, were excluded from the analyses.
At 105 days of age, a random sample of 10 single male lambs from each genotype was chosen each year for detailed carcass and meat quality evaluation. Live weight, hot carcass weight and carcass yield were recorded for each lamb. Also muscle, total fat, kidney fat, bone and tendon were determined by dissecting one side of each carcass at the slaughter house of Meat Technology Institute of INTA Castelar (Buenos
Aires). These measurements were expressed as per-centage of total side weight. Flavor, aroma, tender-ness, juiciness, connective tissue and general acceptability were determined from m. Longissimus dorsi (6th to 10th ribs). Cooked meat samples (AMSA, 1978) were evaluated by 7 trained panelists using an 8 point scale according to Cross et al. (1978) (1 extremely bland, tough, dry and abundant connective tissue to 8 extremely intense, tender, juicy and without connective tissue detectable).
Birth weight (BW), weaning weight (WW) and daily gain (PWG) were analyzed by least squares method using PROC GLM procedure (SAS, 1988). A model with year, genotype, sex and birth type and their interactions as ®xed effects was used. For WW and WWG birth weight and lamb age were added in the model as covariables. Paired comparisons among the three groups were performed by t-test. Birth weight for singles and twins was analyzed jointly and separately. Carcass traits and organoleptic meat characteristics were analyzed using a model with year, genotype and year genotype effects. Differences between meat acceptability were analyzed by Fried-man Rank test (Steel and Torrie, 1980).
3. Results and discussion
3.1. Ewe weight
During the study live body weight of C, PC and P ewes averaged 64.5, 63.1 and 70.2 kg, respectively (P< 0.05).
3.2. Lamb birth weight
observed in the second generation of intense mating (Saoud and Hohenboken, 1984).
3.3. Preweaning weight gain and weaning weight
PWG and WW results are presented in Table 1. The effects of year (P0.001), genotype (P<0.058), birth type (P0.001) yeargenotype (P< 0.01), year sex (P< 0.008) and yearbirth type (P< 0.003) were signi®cant on both PWG and WW. In addition, the effects of age (P0.001) and genotype sex (P0.032) were signi®cant on WW and birth type sex (P0.02) and birth type sex year (P0.03) signi®cant on PWG. The above results showed that a signi®cant proportion of total variance was explained by year effect. This year variability, besides climatic and management effects includes sire
size variation. PWG of Pampinta genotype was super-ior to the others and PC slightly superior to C (Table 1). Generally P and PC PWG tended to be better (P< 0.05) than C and P and PC were 29.05% and 11.33% superior to C, respectively.
PWG are in agreement with preliminary observa-tions (Suarez et al., 1995) and corroborate P super-iority and the halfway position of F1 crosses that had better performances than C offspring. In spite of these differences, PWG of PC was more close to PWG of C. The high live weight gain of P lambs could be attributed to a greater maternal ability and milk pro-duction of P ewes (Suarez et al., 1996) which could rear their lambs more ef®ciently than C ewes (Kremer et al., 1995). Likewise, WW showed the same trend of PWG, according to previous results (C. Torrado, 1995, personal communication) that showed that F1 lambs
Table 1
Least-squares means and standard errors for lamb performance traits
Effects n Birth weight (kg) Av. daily gain (g) Weaning weight (kg)
Year
a,b,cColumn mean values of different years or groups with different superscripts are signi®cantly different,P< 0,05. C
Corriedale, P
between Pampinta regional Corriedale ewes were 15% heavier than regional ewe lambs, probably as a result of the small size of regional ewes. Preweaning results indicate that P rams are recommended for crossing smaller framed ewes.
3.4. Carcass traits and sensory evaluation
Averages for parameters measured at slaughter for the three genotypes are presented in Table 2. Genotype effect was signi®cant for slaughter (P0.0013) and hot carcass (P0.0005) weights. Only the year effect was signi®cant for carcass yield (P0.03). The year effect was also signi®cant for muscle, kidney fat and tendon percentages (P0.000l) and genotype effect was signi®cant for muscle (P0.013) and fat (P0.05) percentages. Muscle and fat of P and PC showed the same trends. Comparatively P and PC had 5.9% (P0.013) and 7.2% (P0.006) more muscle than pure C, while C lambs were 18.8% (P0.056) and 21.2% (P0.037) fatter than P and PC lambs, respectively.
Pampinta and PC carcass tended to be higher in muscle and bone and lower in total carcass fat, than those of C. Likewise, P and PC carcasses had high muscle and low fat proportions, resulting in a high mean muscle to fat ratio of 4.36 : 1 (P) and 4.82 : 1 (PC) compared with 3.6 : 1 for C. Previous studies showed that East Friesian purebred sires had high effect on progeny muscle storage and less fat deposi-tion (Bublath et al., 1981). Under similar productive conditions P and PC obtained better live weight gain and carcass quality and showed that P breed can
be used to improve meat characteristics of ¯ocks for local and external markets through high muscle and low fat deposition.
Means presented in Table 3 indicated that in gen-eral, tenderness and juiciness had good scores and ¯avor and aroma received rather high scores, however there were no signi®cant differences for any of these organoleptic measurements between genotypes. Pane-lists only showed slightly Rank Test signi®cant (X2 7.17; P< 0.05) preferences in tenderness for PC meat samples during 1991 and for (X26.61;P< 0.05) P samples during 1993, both compared with C meat samples. However, these rank differences were not important to differentiate genotype samples in ¯avor, aroma, juiciness and tenderness. As a whole these sheep meat samples can be de®ned as of slightly intense ¯avor, rather juicy, tender and practically without connective tissue. Previous observations of Garriz et al. (1994) indicated that carcass and
Table 2
Least-squares means and standard errors for carcass measurements of lambs
Parameters Corriedale (C) PC Pampinta (P)
Number of lambs 30 30 30
Slaughter weight (kg) 26.6a2.7 31.6b4.2 35.4c4.5
a,b,cLine mean values with different superscripts are signi®cantly different,P< 0.05.
Table 3
Organoleptic evaluations performed by panel of trained judges (Point scale used (1 to 8): 1 extremely bland, tough, dry and abundant connective tissue; 8 extremely intense, tender, juicy and without connective tissue detectable. None of the genotype differences was signi®cant)
Parameters Corriedale (C) PC Pampinta (P)
No. of samples 30 30 30
Aroma 5.20.8 5.20.6 5.20.5
Flavor 5.20.9 5.01.1 5.11.0
Juiciness 5.20.8 5.10.9 5.21.0
meat analyses of P and PC under similar slaughter age and rearing conditions had more carcass weight, more muscle, less fat and without meat quality differ-ences.
In conclusion, the present results complement those on reproductive qualities: high proli®cacy and milk yield of the Pampinta breed (Suarez et al., 1996) and encourage the use of this breed for crossbreeding programs to produce early ®nished and lean lambs. However, these data are limited to one maternal genotype and for one farming system, and additional information with other breeds and crossbreeding sys-tems or under other management conditions is needed to further assess the favorable characteristics of Pam-pinta sheep.
Acknowledgements
Sincere thanks are addressed to Jorge Gavella and Nelson Zentt for their assistance.
References
AMSA, 1978. Guidelines for cookery and sensory evaluation of meat. American Meat Science Association, Chicago, Illinois 60611.
Bublath, A., Parodi, J.J., Perez, J.L., 1981. Carcass composition of sheep purbred and crossbreds. Rev. Arg. Prod. Anim. 7, 332± 347.
Cross, H.R., Moen, R., Stan®eld, M., 1978. Guidelines for training and testing judges for sensory analysis of meat quality. Food. Tech. 32, 48.
Flamant, J.C., Ricordeau, G., 1969. Croisements entre les races ovines PreÂalpes du Sud e Frisonne (Ostfriesisches Milchschaf). I, La brebis laitiere de Frise Orientale. Elevage en race pure. Utilization en croisements. Ann. Zootech. 18, 107±130. Garriz, C.A., Suarez, V.H., Fort, M.C., 1994. Carcass quality and
yield of Pampinta breed lamps. 18 Argentine Animal Produc-tion Congress, Buenos. Aires. Rev. Arg. Prod. Anim. 14(Suppl. 1), TP 9.
Kremer, R., Barbato, G., Roses, L., Perdigon, F., Rista, L., Herrera, V., 1995. Milk production of Corriedale sheep. Enivironmental effects and weaning strategies. Rev. Arg. Prod. Anim. 15(3/4), 870±873.
Medrano, C.A., 1975. New importation of East Friesian german sheep breed. Informativo de Tecnologia Agropecuaria paara la RegioÂn SemiaÂrida Pampeana, EBA Anguil. NTA 64, 6. SAS Institute, Inc., 1988. SAS/STAT User's Guide, Release 6.03
ed. SAS Institute, Inc., Cary NC, p. 1088.
Saoud, N.B., Hohenboken, W.D., 1984. Phenotypic relationships among early life traits and life ewe production ef®ciency. J. Anim. Sci. 59, 607±609.
Sidwell, G.M., Miller, L.R., 1971. Production in some pure breed of sheep and their crosses. II Birth weight and weaning weight lambs. J. Anim. Sci. 32, 1090±1094.
Steel, R.D.G., Torrie, J.H., 1980. Principles and Procedures of Statistics: A Biometrical Approach. McGraw-Hill, New York. Suarez, V.H., Fort, M.C., Busetti, M.R., Cayssials, H., Garriz, C.A.,
Gallinger, M.M., 1995. Pre-weaning evaluation of Pampinta, Corriedale and PampintaCorriedale lambs. Rev. Arg. Prod. Anim. 15(3/4), 868±870.
