Effets de l’incorporation de Stipa tenacissima L. et les feuilles d’olivier dans l’alimentation des chèvres sur la production et la qualité du lait

Pour faire face aux variations des facteurs climatiques et gérer les sécheresses saisonnières et prolongées, les éleveurs du sud tunisien font recours à diverses stratégies d'adaptation. Ainsi, pour assurer les besoins alimentaires de leurs troupeaux, ils profitent des saisons favorables pour créer des réserves alimentaires notamment par la fauche d'espèces végétales non cultivées, notamment la collecte des résidus de récolte tels que les feuilles d'olivier. Le cas de l'Alfa «Stipa tenacissima L.» constitue l'un des exemples les plus connus dans les régions montagneuses du sud tunisien. Le présent travail a été réalisé dans le sud-est tunisien et vise une meilleure compréhension des pratiques traditionnelles de récolte et de fanage de Stipa et son utilisation en alimentation animale. Des enquêtes, auprès des agro-pasteurs de la région de Bénikédache ont été menées. Ainsi, selon les pratiques traditionnelles des éleveurs de l'incorporation des feuilles d'olivier séchées et l'alfa dans le régime alimentaire des animaux, un essai d'alimentation a été réalisé sur 20 chèvres de la population locales (âge moyen = 4,10 ± 0,70 ans et poids moyen = 25,20 ± 3,36 kg). Les chèvres ont été divisés en deux groupes de 10 animaux chacun, le premier a reçu le foin d'avoine (Groupe C : contrôle), le deuxième a reçu Stipa tenacissima +feuilles d'olivier séchées (Groupe STO) avec une complémentation (250 g du concentré commercial) pour les deux groupes. Les résultats de l'enquête ont révélé que la fauche de l'Alfa est conditionné par la période des premières pluies automnales et que 90% des enquêtés le ramassent à partir du début de mars jusqu'à la fin du mai. Après son séchage, l'Alfa est stocké soit en tas à l'air libre (30%) soit dans un local fermé (70%). Ces enquêtes ont montré que l'Alfa est utilisé particulièrement en été durant les années favorables (80%) et toute l'année en cas de disette (75%). L'essai de l'alimentation a montré que la production laitière a été similaire dans les deux groupes. Le taux de la matière grasse a été plus élevé dans le lait du groupe STO (5,01 et 5,44 %, respectivement). La densité, les teneurs en protéines et en lactose ont été comparables dans les deux groupes. L'Alfa est utilisé comme une ressource fourragère et son utilisation en alimentation animale peut améliorer la qualité nutritionnelle du lait

Coexistence between camels and wild animals

Abstract Livestock, especially small ruminants and camels, have been implicated for negatively affecting the abundance and distribution of other large wild animals in desert areas. We tested whether the occurrence of two emblematic species, the Dorcas gazelle (Gazella dorcas) and Houbara bustard (Chlamydotis undulata undulata), in south-eastern Tunisia was affected by camel abundance. Data were collected during March and April 2004. The study area was divided into 32 400 km2 sample units (20 km x 20 km) distributed over a regular grid. Within each unit, five sampling sites were randomly placed 3 km apart along a line transect. Each sampling site was visited once for a single 30-minute survey session. During these monitoring periods, we collected data on Houbara bustards and dorcas gazelle presences. We also recorded the number of sheep, goats and camels. Areas occupied by these two wild species were characterized by a significantly higher number of camels than unoccupied areas. The occurrence probability of these species was positively correlated with the number of camels. These results may be explained by the fact that the two wild species share similar habitat requirements with camels. The three species coexist in open areas and seem to avoid urbanised and agricultural areas. Camels may not compete with the other two wild species because camels generally consume poor-quality plants that are generally unpalatable and indigestible for these two species

Usporedba sastava i profila proteina sirutke majčinog, devinog, magarećeg, kozjeg i kravljeg mlijeka

The aim of this study was to compare the physicochemical parameters of milk samples of five different species: cow, goat, donkey, camel and human. Also the analysis of whey protein profile in different milk samples was performed by anion-exchange fast protein liquid chromatography (FPLC) while polyacrylamide gel electrophoresis was used to identify a single fraction. Camel milk was the most acid (pH 6.460±0.005) and the richest in total proteins (3.41±0.31 %) and ash (0.750±0.102 %), whereas donkey milk had a neutral pH (7.03±0.02) and characterised by low proteins (1.12±0.40 %) and fat (0.97±0.03 %) content, being very close to human milk. Proteomic analysis of cow, goat, donkey, camel and human milk highlighted significant interspecies differences. Camel milk was similar to human milk in lacking of β-lactoglobulin and richness of α-lactalbumin. The knowledge gained from the proteomic comparison of the milk samples analysed within this study might be of relevance, both, in terms of identifying sources of hypoallergenic alternatives to bovine milk and detection of adulteration of milk samples and products.Cilj ovog istraživanja bio je usporediti fizikalno-kemijska svojstva 5 različitih vrsta mlijeka - kravljeg, kozjeg, magarećeg, devinog i majčinog. Primjenom ionske izmjene i brzo-proteinske tekućinske kromatografije (FPLC) provedena je i analiza profila proteina sirutke, dok je pomoću poliakrilamid gel elektroforeze identificirana svaka pojedina frakcija. Devino mlijeko imalo je najveću kiselost (pH 6,460±0,005) te najviše udjele proteina (3,41±0,31 %) i mineralnih tvari (0,750±0,102 %). S druge strane, magareće mlijeko imalo je pH vrijednost u neutralnom području (7,03±0,02) te niske udjele proteina (1,12±0,40 %) i mliječne masti (0,97±0,03 %) uslijed čega je bilo najsličnije majčinom mlijeku. Proteomička analiza uzoraka kravljeg, magarećeg, devinog i majčinog mlijeka rezultirala je značajnim razlikama ovisno o vrsti mlijeka. Devino mlijeko pokazalo se vrlo slično majčinom zbog odsutnosti frakcije β-laktoglobulina te visokog udjela α-laktalbumina. Rezultati dobiveni proteomičkom analizom različitih vrsta mlijeka mogu poslužiti za pronalaženje hipoalargenih alternativa kravljem mlijeku, ali i kao pomoć pri određivanju patvorenja mlijeka i mliječnih proizvoda

Effect of Thermal Treatments on the Fatty Acids Composition, Antioxidant and Anti-inflammatory Properties of Camel Milk

The present research was conducted to study heat treatment's effect on camel milk’s physicochemical and biological activities. Milk samples were heated at 63°C for 30 minutes, 90°C for 3 minutes, and 100°C for 3 minutes. After heating, the physicochemical: pH, acidity, Fat, Dry matter, proteins, and fatty acids composition as well as the antioxidant and anti-inflammatory activities of all samples were determined. The antioxidant activity of camel milk was evaluated by different assays, including free radical-scavenging activity (DPPH and ABTS) and ferric-reducing power assay (FRAP). Results showed that the heat treatment process increased significantly (p<0.05) the viscosity, total solids, ash, and lactose content. Although, the monounsaturated fatty acids and particularly the oleic acid were significantly decreased after heat treatment. Heat treatment didn’t show any significant effect on antioxidant activities. While a significant increase (p<0.05) was shown after boiling the milk in the anti-inflammatory activity. Therefore, pasteurization could be the greatest heating process to ensure the microbiological safety and the stability of the micronutrients in milk

Daily rhythms of behavioral and hormonal patterns in male dromedary camels housed in boxes

Background. Daily rhythmicity has been observed for a number of hormonal and behavioral variables in mammals. It can be entrained by several external factors, such as light-dark cycle and scheduled feeding. In dromedary camels, daily rhythmicity has been documented only for melatonin secretion and body temperature. In this study, the daily rhythmicity of behavioral repertoire, cortisol and testosterone levels was investigated in captive male camels. Methods. Six clinically healthy male dromedary camels (Camelus dromedarius) were used. The animals were housed in single boxes for 24 h daily and fed twice a day. Over a period of 48 h, behavioral observations were made and blood samples taken every two hours. The data were analyzed using diurnality index, conisor analysis and PROC mixed procedure. Results. The diurnality index for rumination and lying down was close to 0 (respectively, 0.09 and 0.19), while the indices for stereotypy, standing, feeding and walking were close to 1 (respectively, 0.74, 0.84, 0.92 and 0.85). Cosinor analysis revealed daily rhythmicity for all behaviors and for cortisol levels (acrophase at 12:57) but not for testosterone. Rumination and lying down (inactive behaviors) reached a peak during the scotophase, whereas feeding, walking and stereotypy (active behaviors) reached a peak during the photophase around midday. Cortisol level and expression of stereotypies peaked before and after food distribution and were negatively correlated (r =-0.287, P = 0.005). Testosterone levels and expression of sexual behaviors were stimulated by the visual and olfactory contacts with the females and were positively correlated (r =0.164, P =0.040). Testosterone was also negatively correlated with cortisol (r =-0.297; P =0.003). Discussion. These preliminary results provided new knowledge about the daily rhythm of behaviors in camels housed in boxes, suggesting that camels exhibit diurnal behavior pattern in the maintenance conditions outlined in the study. Daily rhythmicity seemed to be entrained not only by the light-dark cycle but also by scheduled feeding. The rise in stereotypy after food distribution could be due to the persistence of feeding motivation and frustration after the ingestion of food. Therefore, feeding practices should be improved to satisfy the foraging and feeding motivation of these camels. Behavioral and hormonal daily patterns in camels should be taken in consideration to adapt the management system, giving the animals more freedom during the light period and a diet richer in fiber, so as to improve reproductive performance, health and welfare

Physicochemical and antioxidant properties of freeze-dried dromedary skim colostrum and milk powder

Cilj ovog istraživanja bio je utvrditi fizikalno-kemijska svojstva i antioksidativnu aktivnost devinog obranog kolostruma i mlijeka u prahu obrađenog postupkom liofilizacije. Dobiveni rezultati pokazali su da je obrani prah kolostruma imao veći udio proteina u usporedbi s mlijekom u prahu, koje je s druge strane imalo veći udio laktoze i pepela. Analiza mineralnog sastava pokazala je da su koncentracije kalcija i magnezija veće u obrađenom prahu kolostruma, dok se koncentracija željeza nije bitno razlikovala između obranog kolostruma i mlijeka u prahu. Mjerenja parametara boje pokazala su da je devin kolostrum u prahu crveniji, ali manje žut i bijel od obranog devinog mlijeka u prahu. Nadalje, obrano devino mlijeko u prahu imalo je veću gustoću i veću nasipnu gustoću. Topljivost proteina u obranom kolostrumu u prahu bila je znatno veća nego u obranom mlijeku u prahu, i to u širokom rasponu pH (3-8). Antioksidacijska aktivnosti određivana je korištenjem različitih in vitro testova, uključujući 2,2-difenil-l-pikrilhidrazil (DPPH) i 2,2’azino-bis (3-etilbenztiazolin-6-sulfonska kiselina) (ABTS) reducirajuću aktivnost radikala, kao i FRAP metodu te kapacitet keliranja željeza. Antioksidacijska aktivnost obje vrste ispitivanih uzoraka pokazala se ovisnom o ispitivanoj količini uzorka. Aktivnosti redukcije radikala DPPH i ABTS metodama bile su slične za obrani kolostrum i mlijeko u prahu, dok je aktivnost dobivena FRAP metodom te sposobnost keliranja željeza bila izraženija u obranom devinom kolostrumu, bez obzira na ispitivanu koncentraciju. Stoga se postupak liofilizacije može upotrijebiti kao djelotvoran način proizvodnje praha iz obranog devinog kolostruma i mlijeka u prahu s očuvanom hranjivom vrijednosti i antioksidacijskim svojstvima.This study aimed to determine the physicochemical properties and antioxidant activities of dromedary skim colostrum and milk powder produced by freeze-drying. Results of the study showed that skim colostrum powder possessed higher protein content compared to milk powder whereas this latter had greater lactose and ash content. The analysis of mineral content revealed that calcium and magnesium levels were higher in skim colostrum powder while the iron level did not differ significantly between skim colostrum and milk powder. The measurements of colour characteristics indicated that dromedary skim colostrum powder was redder, but less yellow and white than dromedary skim milk powder. Further, dromedary skim milk powder had higher bulk density and tapped bulk density. Protein solubility of skim colostrum powder exceeded that of skim milk powder over a wide range of pH (3-8). The antioxidant activities were evaluated using various in vitro tests, including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging activities, ferric reducing power assay and ferrous chelating activity. Both dromedary skim colostrum and milk powder exhibited antioxidant activities in a dose dependent manner. DPPH and ABTS radical scavenging activities were almost similar for skim colostrum and milk powder whereas ferric reducing power and ferrous chelating activity were more pronounced in dromedary skim colostrum powder whatever the concentration tested. Hence, freeze-drying process could be used as an effective tool for producing powder from dromedary skim colostrum and milk with nutritional and antioxidant properties

Moringa oleifera leaves: LC-ESI-MS analysis of phenolic compounds and antioxidant activities

Research on bioactive compounds derived from medicinal plants is still topical and their applications are of interest to food industry, phytopharmacy and cosmetics. The present study deals with the phenolic compounds profile and antioxidant activities of Moringa oleifera Lam. leaves. Therefore, this work is a contribution to study the potential of M. oleifera as a new crop in Tunisia. Composition of phenolic compounds was realized using LC-ESI-MS analysis. Antioxidant activities were assessed using many complementary methods. Extracts from Moringa leaves contained interesting amounts of total phenolics (33–99 mg GAE/g extract) and flavonoids (7–18 mg QE/g extract), with appreciable antioxidant activities in Fe3+ reducing (EC0.5: 0.5–1.1 mg/ml), DPPH• radical-scavenging (IC50: 0.6–1.9 mg/ml), β-carotene/linoleic acid bleaching (IC50: 66–120 µg/ml) and Fe2+ chelating (IC50: 0.5–0.8 mg/ml) assays. Quinic acid, gallic acid, quercetin-3-O-galactoside and quercetin-3-O-rhamnoside were the major compounds measured in the different extracts (5.5–13.5 mg/g extract). M. oleifera grown in oasis of Chenini-Gabes, southeastern Tunisia, can be a source of potent antioxidants for various food, nutraceutical or cosmeceutical applications