C. KOUKI

R. BERGAOUI

Département de Production Animale : Institut National Agronomique de Tunisie INAT, 43, Av. Charles Nicolle, cité Mahrajène 1002 Tunis, Tunisie

Abstract - The aim of this study was to determine the effect of early heat acclimatization applied to broiler restricted to 50% ad libitum on growth performances, mortality rate and meat yields of chickens exposed at the age of 56 days to heat stress during 10 hours. The experiment was conducted on 800 chicks divided into 4 groups: T (fed ad libitum and not acclimatized), R (restricted to 50% ad libitum from 21 to 35 days and not acclimatized), RAC (exposed to 39°C ± 1°C during 24 hours and restricted to 50% ad libitum from 21 to 35 days) and AC (exposed to 39 °C±1°C during 24 hours at 5 days). Mortality rates of RAC group (10%) and AC (12%) were lower during heat stress (40C°±1 during 10 hours) at the age of 56 days compared to other groups T (34%) and R (26%). Results of this study confirm that thermal conditioning reduces mortality at finishing period and increases thermotolerance in chickens during heat stress. Internal rectal temperatures of acclimatized groups taken at 56 days were significantly higher (p <0.05) than not acclimatized groups. Blood T3 (triiodothyronine) rate is reduced during heat stress of RAC and AC groups. Restricted chickens expressed compensatory growth. During refeeding until 56 days the RAC chickens have expressed a similar average daily gain to that of T and AC groups. During the second week of restriction the best feed efficiency correspond to that of RAC (2,06 ±0,4)chickens and R(1,91±0,19). Abdominal fat deposition of chickens slaughtered at 42 days and 60 days of age, is not affected by food restriction not by thermal conditioning. Thigh, breast and cold carcass weights are not affected neither by thermal conditioning nor by the feed restriction nor by the combination of both of them. In conclusion, early acclimatization associated with feed restriction to 50 % ad libitum improves growth performance during the restriction and the refeeding period and reduce mortality at finishing period.

Keywords: thermal conditioning – performances –food restriction- Broiler

Résumé - L’objectif de notre expérience est l’étude de l’effet de l’acclimatation thermique précoce appliquée à jeune âge (5jours) et associée à une restriction alimentaire quantitative de 50% ad libitum sur les performances de croissance, la mortalité et le rendement de viande du poulet de chair. L’essai a été réalisé sur un ensemble de 800 poulets divisé en 4 lots : un lot T( alimenté à volonté et non acclimaté ) , R( rationné à 50% ad libitum de J21 à J35 et non acclimaté ) , RAC ( acclimaté à J5 et à une température de 39°C ±1°C durant 24 heures et rationné à partir J21 à J35 à 50% ad libitum ) et AC ( acclimaté à J5 à une température de 39°C ±1°C durant 24 heures ). Les taux de mortalité dans les lots RAC (10%) et AC (12%) ont été plus faibles comparés aux lots T (34%) et R (26%). Nos résultats confirment que l'acclimatation à jeune âge(J5) réduit fortement la mortalité en période de finition et accroit la thermotolérance des poulets lors du choc thermique, les températures rectales prises à J56 sur les poulets des lots acclimatés sont significativement supérieures (p<0.05) à celles des poulets non acclimatés. Le taux sanguin en T3 est réduit lors du choc thermique chez les lots RAC et AC. Lors de la réalimentation, les poulets rationnés ont exprimé une croissance compensatrice. Les poulets du lot RAC ont exprimé un GMQ moyen similaire à ceux des lots T et AC lors de la réalimentation. Durant la restriction et lors la réalimentation l'indice de consommation le moins élevé correspond à celui des poulets RAC. Le dépôt de gras abdominal des poulets abattus aux âges J42 et J60 n’a pas été affecté par la restriction alimentaire ni par l'acclimatation. Les rendements en cuisse, en filet et en carcasse froide ne sont pas affectés par l’acclimatation ni par la restriction ni par l’association des deux. En conclusion, l’association de la restriction à 50% ad libitum à l’acclimatation thermique affecte positivement les performances de croissance des poulets lors de la réalimentation en réduisant le taux de mortalité en période de finition.

Mots clés: Acclimatation thermique- restriction alimentaire-performances- poulet.

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S. AYED^1*

Z. CHAMEKH²

O. AYED-SLAMA ²

H. AMARA²

¹ Université de Carthage, Pôle Régional de Recherche Développement Agricoles du Nord Ouest Semi Aride-Kef, Tunisie

² Laboratoire de Génétique et d’Amélioration des Céréales de l’Institut National Agronomique de la Tunisie

Abstract - In this study, durum wheat x maize cross is used as an alternative for haploid plants production. This method is based on embryos rescue. The objective of this study was to analyze the influence of environmental factors in durum wheat crossed with maize on the basis of three parameters: percentage of developed ovaries, of embryos and of regenerated haploid plants. Four Tunisian durum wheat genotypes namely Jenah khotifa, Biskri, Karim and Razzek used as female parent were crossed with a maize genotype (Pioneer 37Y15) used as male parent. Results showed a significative difference between the two cropping season 2007-2008 and 2008-2009 for all parameters studied. Percentage of developed ovaries and embryos formed recorded about 45.33 % and 7.35% for the cropping season 2007-2008 and 29.15% and 6.35% for 2008-2009 cropping season 2007-2008. Genotypes Jeneh khotifa (47.5% and 9.7%) followed by Biskri (42.1% and 4.7%) showed the best percentage of developed ovaries, of embryos. A positive corrélation were noted between percentage of developed ovaries and embryos developed (0.67**) and between percentage of developed ovaries and haploid plants regenerated (0.69**).

Keywords: durum wheat, in vitro, maïs, regeneration

Résumé - Dans cette étude, la technique d’hybridation interspécifique blé dur x maïs a été adoptée comme une alternative pour la production de lignées haploïdes. Cette méthode repose sur le sauvetage in vitro d’embryons immatures. A cet effet, quatre génotypes de blé dur Jenah Khotifa et Biskri, Karim et Razzek, utilisés comme parent femelle, sont croisés avec un génotype de maïs (Pioneer 37Y15) utilisé comme parent mâle. Les croisements interspécifiques ont été effectués durant les deux années successives (2007-2008 et 2008-2009) pour déterminer l’effet des facteurs environnementaux tels que la température et/ou l’humidité pendant la phase de nouaison et de la formation des embryons. Trois paramètres ont été mesurés à savoir le taux de nouaison, d’embryogenèse et de régénération des plantules haploïdes. Les résultats obtenus ont montré une différence significative entre les deux années d’expérimentation pour tous les paramètres mesurés. Les taux de nouaison et d’embryogenèse des 4 génotypes passent de 45,33 %, 7,35% pour la première année à 29,15%, 6,35% pour la deuxième année. Les génotypes Jeneh khotifa (47,5%, 9,7%) suivi de Biskri (42,1%, 4,7%) ont montré les taux de nouaison et d’embryogenèse les plus élevés. Une corrélation positive a été notée entre le taux de nouaison et le taux d’embryogenèse (0,67**) ainsi que entre le taux d’embryogenèse et le taux de régénération de plantes haploïdes (0,69**).

Mots clés: blé dur, in vitro, maïs, régénération

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W. Abidi*

Centre Régional des Recherches Agricoles (CRRA), Sidi Bouzid, Tunisia.

Abstract - Pomological attributes and geometric properties of four pistachio cultivars (Mateur, Elguetar, Kerman, Ohadi) grown in the orchard of the Regional Center of Agriculture Research Sidi Bouzid Tunisia, were studied. This work aims to select suitable cultivars for these environmental conditions and determine important physical properties useful for the design of various separating, handling, storing and drying equipment. Agronomical traits such as production, trunk cross sectional area, yield efficiency, number of grapes/tree, number of fruits/grapes, number of fruits /100g, kernels weight, kernel dry weight /nut and dry weight ratio were evaluated. Physical properties of pistachio kernel such as length, width, thickness, arithmetic diameter, geometric diameter, sphericity and surface area, were determined. Our results showed higher yield for Mateur cultivar than the others cultivars. Ohadi showed higher fruit dimensions, arithmetic diameter, geometric diameter and sphericity, on the other hand this variety showed lower level of splits fruits (52%) and a higher level of blanks rate (26%). The choice of the most adapted and effective pistachio varieties in terms of vigour, production and geometric properties in the studied area are as follows: the first is the Mateur variety followed by Ohadi and Kerman and the last cultivar is Elguetar.

Keywords: pistachio, nut, kernel, geometric properties

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E. AISSA 

A. MOUGOU

K. KOUKI KHALFALLAH

National Agronomic Institute of Tunisia

Abstract - A greenhouse experiment was carried out during the spring–summer 2014 to examine that arbuscular-mycorrhizal (AM) can enhance growth of pepper plant (Capsicum annuum L.) supplied with Rock Phosphate (RP). Arbuscular mycorrhizal (+AM) and non AM pepper plants were grown in a calcareous soil with three fertilization regimes (without any phosphate amendment, supplied with Triple super phosphate (TSP) and supplied with RP). Mycorrhizal inoculation increase significantly plant biomass, height, leaves area and stems diameter for all fertilization regimes. The uptake of phosphorus was influenced by AM inoculation, hence inoculated plant supplied by TSP and RP had statically similarly and higher concentration of P in leaf tissue than unfertilized plants and non inoculated plants amended with P fertilizers. A slight increase of available P was registered in soil around roots of inoculated plant amended with RP.

Keywords: Gafsa Rock Phosphate, Arbsucular mycorrhizal fungi, Capsicum annuum L.

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A. Bettaieb^1*

N. Moujahed¹

G. Hamdaoui²

R. Ksouri³

¹ Animal Resources and Food-processing Laboratory, Agronomy National Institut of Tunisia. 43. Av Ch. Nicolle, 1082, Tunis, Tunisia.

² Bioactive substances laboratory, Borj Cedria Biotechnology center, BP 901, 3050, Hammam-Lif, Tunis, Tunisia.

³ Medicinal and Aromatic Plants laboratory. Borj Cedria Biotechnology center, BP 901, 3050, Hammam-Lif, Tunis, Tunisia.

Abstract - Five wild growing species were collected from Zaghouan (eastern-north of Tunisia, semi-arid, limestone) in order to evaluate their chemical composition for an eventual animal use context, particularly the enhancement of animal nutrition and health. These aromatic plants were selected for their highest content in phenolic, flavonoid, condensed tannin, saponin contents and essential oils composition. Results showed that among the studied species, Myrtus communis displayed the highest total polyphenol (101.3 mg GAE/g DW), while Ladandula stoechas, Rosmarinus officinalis, and Thymus vulgaris were the lowest ones (25.78, 22.74 and 20.50 mg GAE/g DW respectively). The amount of flavonoids varied widely between 28.6 and 5.1 mg /g DW in Mentha pelagium and Myrtus communis respectively. In addition, Condensed tannin content in Myrtus (6.39 mg CE/g DW) was higher than other species for which condensed tannin concentration ranged approximately between 1.37 and 3.30 mg/g DW. Concerning saponin content, it was the utmost in Lavandula (12.01 mg/g DW). Besides, the main compounds were 1.8-cineol in Rosmary (39 %) and thymol (61.3%) in Thym. It was concluded that the vegetal diversity in the studied area presented a consequent chemical diversity, available for animals as fed in grazing or in housing conditions. These bioactive molecules, mainly essential oils, may be used for their antimicrobial actions to improve animal health and performance.

Keywords: Polyphenols, flavonoids, condensed tannins , saponins, essential oils.

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R. SERAIRI BEJI^1,2

I. BETTAIEB REBEY²*

S. JAMELEDDINE³

R. KSOURI²

¹Ecole Supérieure des Sciences et Techniques de la Santé de Tunis, BP 176, Bab Souika, Tunisie.

²Laboratoire des Plantes Aromatiques et Médicinales, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050 Hammam-Lif; Tunisie.

³Département de Physiologie, Faculté de Médecine de Tunis; Tunisie.

Abstract - Fenugreek (Trigonella foenum-graecum Linnaeus, 1753) is used in alternative medicine for treating diabetes mellitus and its associated symptoms. The aim of this study was to investigate the antidiabetic, antihyperlipidemic and antioxidant activities of fenugreek in alloxan induced diabetic rats. Diabetes was confirmed after 3 days of single subcutaneous injection of alloxan (120 mg/kg) in albino Wistar rats. Animal’s standard diet was supplemented with fenugreek (5%) for 30 days. Rats were fasted overnight, weighed and then sacrificed on the 31^st day of the experiment. Their bloods were collected and submitted to various biochemical measurements, including blood glucose, total cholesterol (TC), triglycerides (TG) and high-density lipoprotein-cholesterol (HDL-CH). Further, low-density lipoprotein-cholesterol (LDL-CH) was calculated from the data obtained. Oxidative enzymes such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were assessed in serum and pancreas homogenate. The results showed that fenugreek supplementation in diabetic rats significantly decreased the levels of glucose (342.2 ± 23.9 mg/dl vs 171.0 ± 18.7 mg/dl; p< 0.05), TG (0.87±0.17g/l vs 0.49±0.09; p< 0.05), TC (0.95±0.11g/l vs 0.75±0.17; p<0.05) and LDL-CH (0.79±0.5g/l vs 0.53±0.15g/l; p<0.05) compared to diabetic control group. Furthermore, fenugreek increased the level of HDL-CH from 0.11±0.01g/l to 0.14±0.04g/l (p<0.05). These results are accompanied with improved weight gain of diabetic rats compared with the diabetic controls. Concerning oxidative stress, fenugreek significantly improved SOD, CAT and GPx activities both in serum and in pancreas homogenate. Fenugreek demonstrated significant antidiabetic, antihyperlipidemic, and antioxidant activities that may be due to its multiple effects involving both pancreatic and extra-pancreatic mechanisms. Fenugreek has the potential to be used as a dietary supplement for the management of diabetes.

Keywords: antihyperglycemic, antihyperlipidemic, alloxan, antioxidant enzymes, fenugreek

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