Carcass characteristics of Creole goat of Guadeloupe (FWI) as a function of pre-weaning performances and post-weaning management

G Alexandre, R Arquet*, G Gravillon**, J L Weisbecker*** and N Mandonnet

UR 143 Unité de Recherches Zootechniques, Centre INRA-Antilles-Guyane, Domaine Duclos, 97170 Petit Bourg, Guadeloupe
* INRA UE 467 Domaine Expérimental de Gardel, Centre INRA-Antilles-Guyane, 97160 Le Moule, Guadeloupe
** INRA UE 503 Unité Expérimentale en Production et Santé Animale, Centre INRA-Antilles-Guyane, Domaine Duclos, 97170 Petit Bourg, Guadeloupe
*** INRA Domaine Expérimental de Langlade, 31450 Montgiscard
gisele.alexandre@antilles.inra.fr

Summary

Two experiments were designed to run concurrently using 56 Creole male kids of Guadeloupe to assess the effects of feeding modes upon carcass traits. In the first experiment kids were reared after weaning in a rotationally grazed tropical pastures (P) at a mean stocking rate of 1200 kg LW/ha without supplements. In the second experiment kids were fed in stall (S) and received chopped tropical fodder and commercial pellets (50% of diet DM). In both experiments two groups of kids were determined on the basis of their average daily gain (ADG) before weaning (at 87 d): low level (L) and high level (H). Thus treatments were defined as LP vs. HP and LS vs. HS. Kids of P experiment were slaughtered at the end of 8 months of growth, whereas kids of S experiment were slaughtered as soon as the mean live weight of the group reached 19 to 20 kg.

The weights at weaning and at slaughter of LP vs. HP kids were 8.4 vs. 10.6 (P< 0.01) and 18.4 vs. 18.7 (P> 0.05), respectively. The corresponding values for LS vs. HS kids were 7.6 vs. 9.1 (P< 0.01) and 20.8 vs. 19.4 (P> 0.05). The LS kids spent significantly more time in the feedlot stall than the HS (178vs. 107days ; P< 0.01). The hot carcass weight was similar for P kids (6.5 kg) while it was significantly higher (P< 0.05) for LS vs. HS group: 9.5 vs. 8.2 kg. Also the gut content represented 38% vs. 31% of the carcass weight (P<0.05) for LP vs. HP kids; values obtained for LS and HS kids were 23% vs. 27% (P<0.05). Thus the true carcass yield reached 52% for P kids and 5 points more for S kids (no significant difference was observed between groups of L vs. H kids). The colour was mainly pale for P kids while it was pink for S kids. Conformation classification was 2.5 and 3 for P and S groups (scale from 1 to 5). Fat cover score and fat weights did not differ significantly between L and H kids within the P or S experiment. However these variables seem to be lower for pasture fed kids against supplemented kids: 3 and 2 times less for omental and kidney fat, respectively. Irrespective of the pre-weaning ADG level or the feeding mode the proportion of the different cuts was similar; 30% leg, 20% shoulder, 12% neck, 12 % breast.

It was concluded that the mode of feeding slightly affected carcass quality and composition while it had a marked influence on live and carcass weight as well as on the full gut percentage in the LW. More experiments are needed to determine the best mode of feeding specially for low weight kids.

Keywords: carcass composition, carcass yield, feeding level, Creole goat, preweaning ADG

Introduction

In Guadeloupe, goats are raised under the suckling system for meat production. Due to its high production level (Alexandre et al 1999) and good adaptation to tropical conditions (Mandonnet et al 2001), the Creole goat could be a valuable genetic resource for the region (Alexandre and Mandonnet 2005). For flocks reared under intensive grazing systems, the reproductive performances are high (1385 kg LW of weaned kids/ha/year). Despite the fact that the Creole goat is a meat breed, very few studies deal with the assessment of fattening performances and carcass characteristics. The carcass weight, varying from 6 to 8 kg among private farms, does not meet the needs of the formal modern sub-network (Alexandre et al 2008). There is a need to increase the meat production of the Creole goat.

Fattening and carcass performances varies widely with genotype, sex, feeding level, weight or age at slaughter (see review of Warmington and Kirton 1990; Dhanda et al 2003).

Grazing is the most common mode of animal production and tropical forages are of moderate feeding value (Humphreys 1991), and therefore, a limiting factor in animal production. High levels of performances partly depend on the supplementary intake of protein- and energy-rich foods.

Accordingly, there are on-going experiments to test the effects the feeding mode on carcass characteristics while taking into account the growth potential of kids before weaning. A great phenotypic variability of pre-weaning performances (up to 33 % of coefficient of variation) characterises this hardy breed. Given that in a weaner system of production such as in sheep (Villette and Thériez 1981) or in pig (Quiniou et al 2002), the pre-weaning performances may influence post weaning abilities; this factor has been included in this study.

The aim of this paper is to give the first results in this area.

Materials and methods 

The study was undertaken at the INRA-Gardel experimental farm (INRA UE 467) located in the driest region of the Guadeloupe island.

Creole meat type goats, a medium-sized breed (28 kg mature LW for females) were used from weaning to slaughter in two concurrent experiments at pasture without supplement (P) and in feedlot with supplement (S). In the first experiment the kidding period was centred on April (birth weight 1.9 ± 0.2 kg)  while in the second it was centred on June (birth weight 1.8 ± 0.3 kg). Entire male kids were weaned at 87 ± 5 days. The animals were reared on a rotationally grazed tropical pasture (P, n = 24) every 28 days (9.05  MJ ME and 123 g CP per kg DM) at an average stocking rate of 1200 kg LW/ha and received no supplementation. In the second experiment, the animals were supplemented (S, n = 32) and reared in collective pens on a slatted floor. The diet was composed of the same stand of tropical pasture as mentioned above (Table 1), mainly composed of  Digitaria decumbens, Dichanthium sp., Brachiaria mutica and Cynodon dactylon. In addition, they were offered commercial pellet (10.3 MJ ME and 180 g CP per kg DM), composed of maize (32.5%), wheat issues (40.0%), soya bean meal (15.0%) sugar cane molasse (6.0%) and minerals (6.5%).

In both experiments, two groups of kids were determined according to their pre-weaning ADG (Table 2): low level (L; 69 ± 10 g/day) and high level (H; 91 ± 14 g/day). Thus treatments were defined as LP vs. HP and LS vs. HS.

Regular drenching was carried out, to control gastro-intestinal parasitism, monthly for kids from birth to weaning and every two months for weaned kids and goats. External parasites were controlled every two weeks for young and adults (spraying of acaricides).

Kids of P experiment (12 in each group) were slaughtered at the end of 8 months of growth whereas kids of S experiment were slaughtered as soon as the mean live weight of the group reached 19 to 20 kg (14 and 18 in LS vs. HS group, respectively). Prior to slaughter, each goat was weighed. Length of fast (24 hrs) prior to slaughter was standardized for all goats in order to minimize variation in fill. Weights of all items (head, feet, pelt, lungs, liver, heart, and viscera) were taken during the slaughter process. The weight of the gastro-intestinal tract and all of its contents were recorded prior to and after cleaning. The cleaned GI-tract was separated and weighed as large and small intestines and mesenteric and intestinal fat. Hot carcass weight and chilled carcass weight (24 hrs post slaughter) and cut weight (leg, shoulder, neck, ribs, flank) were obtained according to procedures outlined by Colomer-Rocher et al (1987). Kidney and pelvic fat was removed and weighed on the chilled carcass before cutting. Empty body weight (EBW) was calculated by subtracting values of gut content from slaughter weight. Two dressing percentages were calculated, true carcass yield calculated as cold (chilled) carcass weight related to EBW and dressing percentage expressed as proportion of hot carcass weight to slaughter weight (SW). Carcass was graded according to conformation, colour of the meat and fat cover score (Colomer-Rocher et al 1987).

Data were analysed, in each respective experiment, by fitting a model that included the effects of preweaning ADG level using the GLM procedures of SAS (1996). In the P experiment the slaughter weight (kg) was added as a covariable and was kept if it reached significance. In the S experiment the age at slaughter (days) was added as a covariable in the model and was kept if it reached significance.

Results and discussion 

The weights at weaning and at slaughter (Table 3) of LP vs. HP kids were 8.4 vs. 10.6 (P< 0.01) and 18.4 vs. 18.7 (P> 0.05), respectively. The corresponding values for LS vs. HS kids were 7.6 vs. 9.1 (P< 0.01) and 20.8 vs. 19.4 (P> 0.05), respectively.

The HP kid markedly lowered (P<0.01) its ADG after weaning when reared under the limiting pasture conditions. The LS kids spent significantly more time in the feedlot stall than the HS kids (178 vs.107 days; P< 0.01). Although, comparisons are difficult between the two concurrent experiments, animals fed on concentrate-based diets exhibited, as expected, higher ADG (twice more) than those grazing tropical pastures, however, their carcass yield improved slightly (see below).

The hot carcass weight (Table 4) was similar for both P groups (6.5 kg) while it tended to be  higher (P> 0.05) for LS vs. HS group: 9.5 vs. 8.2 kg. Also the full GI tract represented 31% vs. 38% of the carcass weight (P<0.05) for LP vs. HP kids; the respective values obtained for LS and HS kids were 23% vs. 27 % (P>0.05).

These high varying proportions observed between the two experiments, are linked to the feeding mode of the animals. This is in line with the conclusion of Moniruzzaman et al (2002) working with Black Bengal goats, where 41 % of difference for this trait was found between stall feeding and grazing systems. For the P kids, the diet is 100% grazed tropical forages known for its high level of structural elements (Humphreys 1991) leading to a high gut content. That is the reason why a 24h fasting period is recommended in standardized slaughter procedure (Colomer-Rocher et al 1987) in order to reduce the effects of the digestive content.

The true carcass yield reached 52% for P kids and 5 points more for S kids (no significant difference occurred between groups of LS vs. HS kids). The slight difference that appeared between P and S kids for their carcass yields, could be due to, not only their different SW, but also to the effect of the GI tract weight that interfere with the carcass yield mode of calculation. This is in line with results of Hango et al (2007) that did not find differences between different feeding regimens for this trait in Small East African goats. The values were similar to the those reported by Mahgoub and Lu (1998) for Omani goats (52 %) or by Hailu Dadi et al (2005) for Ethiopian kids (49-56%) reared and slaughtered under similar conditions as this present study. The dressing percentage of  S kids (48%) were higher than the Black Bengal ones reared in comparative intensive conditions (40 %: Shahjalal et al  2000; 42%: Moniruzzaman et al 2002) but slaughtered at a lower live weight (10 to 12 kg). The carcass output of P kids (39%) were within the range of values obtained  with Criollo of Chile (46 %, Gallo et al 1996) and West African (38 to 53%, Attah et al 2004) reared and slaughtered in comparative conditions. Comparison of different literature values is difficult because the adult size and the slaughter weight have great influence on the growth potential and on the carcass characteristics in fattening animals, such as in tropical goats of Oman (Mahgoub and Lu 1998).

The fat cover score and the weights of non-carcass fat deposits did not differ significantly between L and H kids within P or S experiment (Table 5).

However, these variables seem to be lower for pasture fed kids against supplemented kids: 3 and 2 times less for omental and kidney fat, respectively. This might be due to the lower energy value of the P diet vs. the S diet. Nevertheless, the fat cover score was low, since the subcutaneous fat depot is thin and poorly developed as reported by many researchers that have studied different breeds or management as reviewed by Warmington and Kirton (1990). As established for this species, the fat storage is predominantly located in the abdominal site. In our present study, the total visceral, kidney and channel fat represented 3.7 to 4.4% of EBW for S kids. These values were similar to those reported for the dwarf Black Bengal goats slaughtered at 12 kg LW (3.7% EBW: Shahjalal et al  2000) or slightly lower than the Dhofari goats of Oman reared and slaughtered under similar conditions (5.3% EBW: Mahgoub and Lu 1998). Differences could be due to the source and quantity of energy supply but also to genetic difference in age of maturity in the cited experiments.

The meat colour varied between pink to red pale for S and P kids (Table 5) and could be due to difference in LW at slaughter between the two experiments.

The weights of carcass cuts varied in the same sense that of carcass and were not tabulated. Irrespective of the pre-weaning ADG level or the feeding mode during fattening, the proportion of cuts was similar; 30% long leg, 20% shoulder, 12% neck and 12 % breast. This is in concordance with the conclusion of Sheridan et al (2003) for Boer goats reporting that diet did not affect the weight of commercial cuts as a proportion of carcass weight.  The distribution of primal cuts (62%) was in the upper range of values reported for the well conformed genetic breeds as reported by Warmington and Kirton (1990) and Dhanda et al (2003).

Conclusions 

These initial results outline the interest of intensifying the feeding level of Creole kids during the fattening period under our conditions. The mode of feeding, tested in the present study, seemed to slightly affect carcass quality and composition while it has a marked influence on live and carcass weight as well as on gut content weight. Marketing practices would depend on the feeding mode. It would be more interesting for breeders, to sell live animals in the case of kids reared at pasture whereas for the others in the form of entire carcasses if a grading system is used.

Further studies are required with more animals to take into account the great variability existing for such traits within the Creole breed. In addition, experiments aimed at increasing the carcass weight (gradually from 18 kg LW to more than 25 kg LW) should be interesting to provide recommendations in terms of fattening systems and to determine the potential of this tropical meat breed. In that sense it will be necessary to improve the supplementation strategies (quantity, quality and cost) especially for light weaned kids (less than 60 g/d pre-weaning ADG). It follows that tropical feed resources (shrubs, tree foliages, by-products) should be used in replacement of commercial pellets to make the system more sustainable.

Acknowledgements 

The authors would like to thank B Bocage,  J Gobbardhan and W Troupe for their technical help. They are grateful to L Onyeka for English corrections to the manuscript. This study was supported by the "Region Guadeloupe" and the “European Community” (FEOGA).

References 

Alexandre G, Aumont G, Mainaud J C, Fleury J and Naves M 1999 Productive performances of Guadeloupean Creole goat during the suckling period. Small Ruminant Research 34: 157-162

Alexandre G, Asselin de Beauville S, Shitalou E and Zebus M F 2008 An overview of the goat meat sector in Guadeloupe: conditions of production, consumer preferences, cultural functions and economic implications. Livestock Research for Rural Development 20, http://www.lrrd.org/lrrd20/1/alex20014.htm

Alexandre G and Mandonnet N 2005 Goat meat production in harsh environments. Small Ruminant Research 60: 53-66

Attah S, Okubanjo A O, Omojola A B and Adesehinwa A O K 2004 Body and carcass linear measurements of goats slaughtered at different weights. Livestock Research for Rural Development 16, http://www.lrrd.org/lrrd16/8/atta16062.htm

Aumont G, Caudron I, Saminadin G and Xandé A 1995 Sources of variation in nutritive values of tropical forages from the Caribbean. Animal Feed Science and Technology 51: 1-13

Colomer-Rocher F, Morand-Fehr P and Kirton A H 1987 Standard methods and procedures for goat carcass evaluation, jointing and tissue separation. Livestock Production. Science 17: 149-159

Dhanda J S, Taylor D G and Murray P J 2003 Part 1. Growth, carcass and meat quality parameters of male goats: effects of genotype and liveweight at slaughter. Small Ruminant Research 50: 57-66

Gallo C, Le Breton Y, Wainnright I and Berkoff  M 1996 Body and carcass composition of male and female Criollo goats in the South of Chile. Small Ruminant Research 23: 163-169

Hango A, Mtenga L A, Kifaro GC, Safari J, Mushi D E, Muhikambele V R M 2007 A study on growth performance and carcass characteristics of Small East African goats under different feeding regimes. Livestock Research for Rural Development (19)  http://www.lrrd.org/lrrd19/9/hang19130.htm

Hailu Dadi, Tatek Woldu and Tesfaye Lema 2005 Comparison of carcass characteristics of Borana and Arsi-Bale goats under different durations of feedlot management. Livestock Research for Rural Development (17)   http://www.lrrd.org/lrrd17/12/dadi17137.htm                   

Humphreys L R 1991 Tropical pasture utilization. Cambridge University, Great Britain. 206 pp

Mahgoub O and Lu C D 1998 Growth, body composition and carcass tissue distribution in goats of large and small sizes. Small Ruminant Research 27: 267-278

Mandonnet N, Aumont G, Arquet R, Varo H, Gruner L, Bouix J and Vu Tien Khang J 2001 Assessment of genetic variability of resistance to gastrointestinal nematode parasites in Creole goats in the humid tropics. Journal of Animal Science 79: 1706-1712 http://jas.fass.org/cgi/reprint/79/7/1706.pdf

Moniruzzaman M, Hashem M A, Akhter S and Hossain M M 2002 Effect of different feeding systems on carcass and non-carcass parameters of Black Bengal goat. Asian-Australasian Journal of Animal Science 15: 61-65

Quiniou N, Dagorn J and Gaudre D 2002 Variation of piglets birth weight and consequences on subsequent performance. Livestock Production Science 78: 63–70

Shahjalal M, Bisshwa M A A, Tareque A M M and Dohi H 2000 Growth and carcass characteristics of goats given diets varying protein concentration and feeding level. Asian-Australasian Journal of Animal Science 13: 613-618

Sheridan R, Hoffman LC and Ferreira A V 2003 Meat quality of Boer goat kid and Mutton Merino lambs. 1. Commercial yields and chemical composition. Animal Science 76: 63-70 http://www.bsas.org.uk/Publications/Animal_Science/2003/Volume_76_Part_1/63/

Villette Y and Theriez M 1981 Influence du poids a la naissance sur les performances d'agneaux de boucherie. II. Composition corporelle et chimique d'agneaux abattus au même poids.  Annales de Zootechnie  30: 169-181 http://animres.edpsciences.org/index.php?option=article&access=standard&Itemid=129&url=/articles/animres/pdf/1981/02/Ann.Zootech._0003-424X_1981_30_2_ART0003.pdf

Warmington B G and Kirton A H 1990 Genetic and non-genetic influence on growth and carcass traits of goats. Small Ruminant Research 3: 147-165

Received 18 April 2008; Accepted 3 October 2008; Published 18 April 2009

Go to top