Growth, feed intake and carcass characteristics of indigenous goats fed local resources in Tunisian arid land

Abstract

Native genetic resource of goats is a pivotal source for meat and milk in southern Tunisia. Feeding is one of the most important activities of goat husbandry. Perceptions on the role of native feed resources for growth and carcass characteristics have not been well studied. Therefore, the present study was designed to help understand and to compare the influences of local forage resources (grass hay, dried olive leaves, Stipa tenacissima and oat hay) on growth performance and carcass characteristics of kids. The kids with the age of 4 months (average live bodyweight of 15 ± 58 kg) were selected for the study. The three study groups in the 90-day trial were as follows: Group C, where animals received oat hay only (control), Group OL, where animals received olive leaves (dried) + S. tenacissima and Group GH, where animals received grass hay. A daily allowance of commercially available concentrate (305 g DM/day) was offered to all groups (making about half of the total DM intake). At the end of the experiment, all animals were slaughtered. Statistical analysis showed that total DM intake was lower (P < 0.001) in C group (490.77 g) than the other two groups having similar DM intake (619.22 and 589.28 g for OL and GH, respectively). Average daily gain was comparable for the three groups (38.33, 40.71 g and 39.52, respectively, for C, OL and GH), with similar final liveweights. Cold carcass weight and carcass yield were not affected by diet treatment. Diet had no significant effect on individual organ weights and carcass composition. The use of the local forage resources evaluated in this trial could be used for the local goat population without loss of productivity when they make up about half of the diet along with a concentrate feed.

Effect of local diets on nutritional and sensory quality of meat of indigenous goats in Tunisian arid regions

“…Coulon and Priolo (2005) suggested that the effect of diet on the sensory profile of meat, in particular in colour change, could be, partly, due to a change in ultimate pH, but also the age at slaughter, the carcasses fatness and the intramuscular fat content contributed to colour and tenderness changes of the meat. This is not the case in the present study since the kids were slaughtered at the same age, and intramuscular fat content was similar in the three groups (Ayeb et al, 2015). The majority of the evidence suggests that there is little or no effect of pre-slaughter growth rate on meat tenderness ( Note: C, Oat hay; CLA, conjugated linoleic acid; Ko, Khortane; MUFA, monounsaturated fatty acids; OL, Stipa tenacissima + dried olive leaves; p, probability; P/S, polyunsaturated/Saturated fatty acids; PUFA, polyunsaturated fatty acids; SEM, standard error of the means; SFA, saturated fatty acids; ΣC18:1t-11t, sum of C18:1 t-6 to t-16 excluded C18:1 t-11; ΣC18:1c-9c, sum of C18:1 cis excluded C18:1 9c; ΣCLA, sum of conjugate linoleic acids.…”

“…Coulon and Priolo () suggested that the effect of diet on the sensory profile of meat, in particular in colour change, could be, partly, due to a change in ultimate pH, but also the age at slaughter, the carcasses fatness and the intramuscular fat content contributed to colour and tenderness changes of the meat. This is not the case in the present study since the kids were slaughtered at the same age, and intramuscular fat content was similar in the three groups (Ayeb et al, ). The majority of the evidence suggests that there is little or no effect of pre‐slaughter growth rate on meat tenderness (Perry & Thompson, ), and the relationship may however depend on the cooking method that is used.…”

Growth, Feed Intake And Conversion Ratio of Improved Goats Fed Brachiaria Grass And Napier Grass Mixed With or Without Leucaena Leaf Meal

“…This could be justi ed by the fact that goats with indigenous bloods are adapted well in the local climatic conditions and well used to consume local forages. A similar observation was reported in a Tunisia arid land where indigenous goats could increase the intake of local forage and thus increase carcass weight (Ayeb et al, 2016).…”