G. Alexandre

Growth performance, carcass quality, and noncarcass components of indigenous Caribbean goats under varying nutritional densities

Studies were conducted to determine the effects of feeding regimens on growth and carcass quality of the Creole goat, a genotype indigenous to the Caribbean. Forty kids weighing 9.0 +/- 1.2 kg of BW were reared indoors after weaning. Four supplement amounts were compared (10 kids per treatment): the G0 group received the basal diet (tropical forage, 8.8 MJ of ME and 108 g of CP/kg of DM) without concentrate, whereas the G100, G200, and G300 groups were offered 130, 230, and 310 g/d of concentrate (13.6 MJ of ME and 209 g of CP/kg of DM), respectively, in addition to the basal diet. The kids were slaughtered according to the standard procedure at 22 to 24 kg of BW for assessment of carcass traits and meat quality. Total DMI increased significantly, from 51 to 78 g/kg of BW(0.75), for G0 to G300 kids, whereas their ADG doubled from 42 to 84 g/d (P < 0.01; P < 0.01, respectively). The G:F values reached 125 to 130 for the G200 and G300 diets and were satisfactory compared with literature values. The carcass weight and dressing percentage (P < 0.01) increased from group G0 to G300, from 9 to 13 kg and from 42 to 51%, respectively. The proportions of the different cuts (related to the carcass weight) did not vary by diet. The conformation score increased significantly (P < 0.05) among the 4 groups from an average score of 3.2 to 4.0 (score/5). There was a significant effect (P < 0.01) of supplement amount on the accumulation of internal fat tissues: the kidney fat weight increased from 113 to 253 g from the G0 to the G300 group. Regardless of the feeding level and amount of internal fat, the carcasses had an acceptable fat cover score, which remained less than 2.6 (score/5). A significant effect was not observed for the ultimate pH and the main color variables of the meat. The cooking loss and the shoulder DM content varied (P < 0.05) with the supplement amount. By increasing the nutritional density of the diet, it was possible to obtain well-conformed and heavy carcasses, with no excessive fattening. Indigenous Creole goats have potential as meat animals when fed to gain more than 80 g/d. The optimal supplement supply with good-quality grass would be approximately 3.69 MJ of ME/d in our conditions. Further studies are required on meat sensory parameters and fatty acid profiles.

Body condition score and adipose cell size determination for in vivo assessment of body composition and post-mortem predictors of carcass components of Creole goats

Abstract The purposes of this study were to estimate precision and accuracy of a scoring method of body condition for Creole does, previously fitted by Santucci et al. (1991) for mediterranean goats. Body condition score (BCS) of 5 levels (1 to 5) with halves, was mainly based upon palpation of sternal subcutaneous adipose tissue (SAT). Repeatability of BCS was 88% (residual standard deviation (RSD) + 0.23 unit) and reproducibility was 80% (RSD = 0.30 unit). BCS and carcass adiposity score (CAS, Colomer-Rocher et al., 1987) appeared as the best predictors of total adipose tissue (TAT) in EBW, and total adipose tissue of carcass. Thickness of SAT and adipose cell size determination appeared to be poor indicators of total body fat and carcass fat. Residual coefficients of variation of linear regression of TAT in EBW and adipose tissue in shoulder by BCS indicated that BCS of Santucci et al. (1991) was a practical and reliable method to assess body composition of Creole does, but more than 5 score levels appeared to be unreliable. For post-mortem estimation, the weight of omental adipose tissue was found to be the best predictive variable of TAT in adult does.

Effect of dietary supplementation on resistance to experimental infection with Haemonchus contortus in Creole kids

The aim of the present study was to test the effect of dietary supplementation on resistance to experimental infection with Haemonchus contortus in Creole kids. One trial with three replicates involved a total of 154 female kids that were chosen from three successive cohorts of the Creole flock of INRA-Gardel in 2007. The kids were placed into four treatments according to the amount of concentrate they received: G0 (no concentrate and a quality Dichantium spp. hay ad libitum, HAY), G1 (HAY+100g commercial concentrate d(-1)), G2 (HAY+200 g commercial concentrate d(-1)), G3 (HAY+300 g commercial concentrate d(-1)). The G0-G3 groups were infected with a single dose of 10,000 H. contortus third stage larvae (L(3)) at Day 0 (D0). Each infected group was comprised of one half resistant and one half susceptible genetically indexed kids. The average breeding values on egg excretion at 11 months of age were distant of 0.70, 0.65, 0.61 and 0.61 genetic standard deviations in G0, G1, G2 and G3, respectively. The faecal egg count (FEC), packed cell volume (PCV), eosinophilia (EOSI) and dry matter intake (DMI) indices were monitored weekly until 42 days post-infection. Enzyme-linked immunosorbent assay was carried out on serum samples to determine the level of IgA anti-H. contortus L(3) crude extracts and adult excretion/secretion products (ESP). The 10,000 L(3) dose received by the kids induced a severe infection: 8000 eggs per gram at the FEC peak, a PCV less than 15% and mortality. Interestingly, the supplemented animals in G3 showed a higher level of EOSI but a lower level of IgA anti-L3 and IgA anti-ESP than non-supplemented animals (G0). Resistant and susceptible kids had significantly different FEC variations within the groups. Susceptible kids had a 1.6 times higher egg output than resistant kids in G0. This difference was not found in the supplemented groups. The results of this study showed that supplementary feeding improved resistance of Creole kids to H. contortus experimental infection.

Intake and digestibility of naive kids differing in genetic resistance and experimentally parasitized (indoors) with Haemonchus contortus in two successive challenges.

We evaluated the effects of infection with Haemonchus contortus on feed intake, digestibility, fecal egg count, circulating eosinophils, and packed cell volume in Creole kids differing in genetic resistance (susceptible, S; resistant, R) to gastrointestinal parasitism and maintained on a similar level of nutrition. The experiment was carried out during 2 periods of 6 wk each differing in immunity development stage. In the first period (acquisition of immunity; period I), 22 naïve male kids (23.4 +/- 0.65 kg of BW) were housed in individual boxes and fed a hay-based diet, and a primary infection was induced. In the second period (expression of immunity; period II), 15 of the initial 22 kids (28.4 +/- 0.77 kg of BW) were submitted to a secondary infection. Housing and management were uniform throughout the experiment. For each period, measurements of intake and digestibility were made at 0, 2, and 4 wk postinfection (WPI) with a single dose of 10,000 infective larvae (L(3)). The DMI and total-tract DM, OM, CP, NDF, and ADF digestibilities were determined using the total feces collection and ad libitum forage supply method. Fecal and blood samples were collected weekly to measure fecal egg count, circulating eosinophils, and packed cell volume. Infection with Haemonchus contortus decreased feed intake during period I. The absence of anorexia in period II was probably due to the acquired immunity of kids. The DMI was affected (P = 0.05) by genetic predisposition to resistance (626 vs. 583 +/- 26 g/d, for R vs. S) and WPI, being greatest in the second WPI (693 vs. 614 and 657 g/d, for WPI-2 vs. WPI-0 and WPI-4, respectively). The latter was related to worm establishment phase and was linked to the lower total tract digestibilities at this point. Digestibilities were least at WPI-2. The fecal egg counts were greater (P < 0.001) in period I than II, and differences between S and R were evident after the fifth WPI in period II. Circulating eosinophils were greater (P < 0.001) in S vs. R. The results suggest that effects of these parasites on intake and digestibility are influenced by the individual genetic resistance and the immunological stage, and the strongest impact occurs between the second and the third WPI, a period during which the immune response is more pronounced, probably due to parasite maturation.

Economic values of body weight, reproduction and parasite resistance traits for a Creole goat breeding goal

A specific breeding goal definition was developed for Creole goats in Guadeloupe. This local breed is used for meat production. To ensure a balanced selection outcome, the breeding objective included two production traits, live weight (BW11) and dressing percentage (DP) at 11 months (the mating or selling age), one reproduction trait, fertility (FER), and two traits to assess animal response to parasite infection: packed cell volume (PCV), a resilience trait, and faecal worm eggs count (FEC), a resistance trait. A deterministic bio-economic model was developed to calculate the economic values based on the description of the profit of a Guadeloupean goat farm. The farm income came from the sale of animals for meat or as reproducers. The main costs were feeding and treatments against gastro-intestinal parasites. The economic values were 7.69€ per kg for BW11, 1.38€ per % for FER, 3.53€ per % for DP and 3 × 10(-4)€ per % for PCV. The economic value for FEC was derived by comparing the expected profit and average FEC in a normal situation and in an extreme situation where parasites had developed resistance to anthelmintics. This method yielded a maximum weighting for FEC, which was -18.85€ per log(eggs per gram). Alternative scenarios were tested to assess the robustness of the economic values to variations in the economic and environmental context. The economic values of PCV and DP were the most stable. Issues involved in paving the way for selective breeding on resistance or resilience to parasites are discussed.

Genetic parameters for body weight, reproduction, and parasite resistance traits in the Creole goat

We estimated the genetic parameters for BW, reproduction, and parasite resistance traits to implement a breeding program for the Creole goat. The traits were preweaning BW at 70 d of age (BW70d), BW at 11 mo of age (BW11), fecal egg count at 11 mo of age (FEC11) for all animals, packed cell volumes of lactating does (PCV), and their fertility (FER) and litter size (LS). We analyzed about 30 yr of data, which included 18,450 records on 11,970 animals from the INRA experimental flock in Guadeloupe (French West Indies). Heritability estimates were low for reproduction traits (0.11 ± 0.02 for LS and FER) to moderate for production traits (0.32 ± 0.03 for BW11; 0.20 ± 0.03 and 0.08 ± 0.02 for the direct and maternal heritability estimates of BW70d, respectively). Heritability estimates for gastrointestinal nematode resistance traits were situated in an intermediate range (0.13 ± 0.05 for PCV and 0.18 ± 0.04 for FEC11). Genetic correlations between FER, PCV, BW11, and the maternal effect of BW70d were altogether positive, whereas LS and FEC11 were almost uncorrelated phenotypically and genetically. These correlations are very favorable for setting up a breeding program, making it possible to improve BW, reproduction, and parasite resistance traits simultaneously.

Production systems of Creole goat and their implications for a breeding programme.

The Creole goat is a local meat breed well adapted to the tropical environment of Guadeloupe, a French island in the Caribbean. A survey of 47 goat farmers was conducted in May 2008 to describe the Guadeloupean goat farming systems. It was the preliminary step for the implementation of a breeding programme for Creole goats. Farmers had 31 does on average. A small number (4%) kept only Creole goats. Most of them (62%) had a mixed herd of Creole and crossbreds. One-third of them (34%) reared only crossbred goats. Farmers appreciate the rusticity and resistance of the Creole goat but consider its growth as too slow. The most desired traits for goat selection were conformation and growth for males (77% of the answers). These traits were also important for females (30% of the answers). Maternal qualities were also frequently cited (maternal behaviour 23%, reproduction 20% and milk production 17%). Disease resistance was not seen as an important trait (10% and 7% of the answers for bucks and does, respectively). A typology constituted of five groups of farmers was also created. Farmers of three groups were retained to participate at a selection programme. They kept Creole goats and have expressed a strong willingness to join a selection programme. The results of the survey suggest that a breeding programme should mostly focus on the Creole goat as a maternal breed. Real consideration should be given to disease resistance. The Creole goat has indeed a key role to play in the sustainability of local farming systems.

Effects of feeding system and slaughter age on the growth and carcass characteristics of tropical-breed steers1

This study aimed to compare the growth performances and carcass characteristics of tropical-breed steers reared in 2 contrasted feeding systems (indoor vs. pasture) and slaughtered at different ages (early vs. late). A total of 309 Creole steers (growing at an initial BW of 173 ± 3 kg and an initial age of 252 ± 4 d) were used over a continuous 12-yr study. Indoor steers were housed in a cattle shed, fed fresh-cut grass plus concentrate, and slaughtered at 14.5 or 17.1 ± 0.1 mo of age. Pasture steers were pasture grazed without supplemental feed, and slaughtered at 17.6 and 21.2 ± 0.1 mo of age. Indoor-fed steers had a greater ADG (786 vs. 517 ± 29 g•d(-1); P < 0.0001) and more carcass fat (164 vs. 145 ± 4.5 g•kg(-1); P = 0.001) than pasture-fed steers. Late-slaughtered steers had decreased ADG (630 vs. 673 ± 27 g•d(-1); P = 0.001) but greater dressing percentages (hot dressing percentage = 55.7 vs. 54.7 ± 0.34%; chilled dressing percentage = 54.5 vs. 53.4 ± 0.34%; P < 0.0001) than early-slaughtered steers. The interaction between feeding system and slaughter age was significant for carcass tissue composition. Whole-carcass muscle content was greater in late-slaughtered steers than early-slaughtered steers, especially in pasture-fed steers (720 vs. 698 ± 6.0 g•kg(-1); P < 0.0001), but less so in indoor-fed steers (707 vs. 700 ± 5.9 g•kg(-1); P = 0.046). Furthermore, increasing slaughter age had no effect on carcass fat in indoor-fed steers (162 vs. 166 ± 4.8 g•kg(-1); P = 0.342), but decreased carcass fat in pasture-fed steers (150 vs. 140 ± 5.0 g•kg(-1); P = 0.014). The results showed that slaughter age and feeding system are 2 major factors that independently affect most of the growth and carcass traits of tropical-breed steers but jointly influence tissue deposition. Our study found that in tropical-breed steers that are grazing, late slaughtering grazing steers increased carcass muscle content without extra fat, thus yielding a carcass quality better suited to consumer choices.

Fatty acid composition of muscle and adipose tissues of indigenous Caribbean goats under varying nutritional densities

The effects of a concentrate diet on growth, carcass fat, and fatty acid (FA) composition of muscle (supraspinatus), perirenal, and intermuscular adipose tissues of Creole goats (n = 32) were evaluated. Goats were fed a tropical green forage Digitaria decumbens ad libitum with no concentrate (G0) or 1 of 3 levels of concentrate: 140 (G100), 240 (G200), and 340 g•d(-1) (G300), respectively. Goats were slaughtered according to the standard procedure at the commercial BW (22 to 24 kg of BW). Goats fed the concentrate diets (G100, G200, and G300) had greater ADG (P < 0.001), cold carcass weights (P < 0.001), and omental (P < 0.01), perirenal (P < 0.01), and intermuscular (P < 0.01) adipose tissues weights. Dietary intake of C18:0, C18:1n-9, C18:2n-6 increased as concentrate supplementation increased (P < 0.001), whereas C18:3n-3 intake was not affected (P > 0.05). Increased concentrate supplementation did not affect (P > 0.05) the proportion of MUFA in all tissues and had very little effect on SFA in perirenal tissue, but increased the PUFA proportion in muscle (P < 0.05). The major effect of feeding increased concentrate was an increase in n-6 PUFA proportions in all tissues (P < 0.001) and, surprisingly, a decrease in n-3 PUFA (P < 0.001). Focusing on FA, which are supposed to have a beneficial or an adverse effect on human health, feeding increased concentrate did not increase the content of any cholesterol-increasing SFA in meat, but increased the n-6/n-3 ratio above 4 when more than 240 g of concentrate was fed per day.

Preweaning Productivity of Suckling Goats and Sheep in Guadeloupe (FWI) under Intensive Reproductive Rate and Grazing Management

In Guadeloupe, small ruminants are reared for meat production under pasture conditions. Intensive rotative grazing systems (irrigated, fertilized and high-stocked tropical pastures) allow satisfactory levels of production but generate high post-grazing residues. Experiments were designed to control these. A system in which residuals were mown (RM) was tested in comparison to the control system (residuals remained, RR). The same design was carried out over two years with Creole goats and Martinik sheep. An accelerated reproductive rate (3 parturitions over 2 years) was carried out. Systems were compared at three parturition seasons per year (dry, intermediate and rainy seasons). Each group was composed of 20 goats (36.0±2.5 kg) or 20 ewes (46.8±2.4 kg). The systems exhibited high levels of productivity in both species compared to other results in the tropics: more than 50 and 30 offspring born alive per hectare and per reproductive season for the goat and ewe flocks, respectively. The annual production at birth was 110 kg kids/ha per year and 133 kg lambs/ha per year (i.e. 21% more). Corresponding values at weaning were 630 kg kids/ha per year and 785 kg lambs/ha per year (i.e. 25% more). The RM system produced 10% more than the RR system in Creole goats, while it produced 35% more in Martinik sheep. Seasonal effects and other factors of variation are discussed.