Potential of white garlic powder (Allium sativum L.) to modify in vitro ruminal fermentation

The current study aimed to evaluate the effect of increasing doses of garlic powder (GaP) on in vitro fermentation characteristics. Two successive 24-hour incubations were run, and gas production was measured at the end of each incubation period. Liquid samplings for each dose were reserved to determine ammonia nitrogen (NH3-N) and true organic matter degradability (TOMD). Partitioning factor (PF) was estimated as the ratio between TOMD and the gas produced at 24 hours of incubation. Microbial biomass (MBM) was estimated on the bases of truly degraded substrate and PF. Results showed that gas production increased (P <0.001) with the addition of 32 and 64 mg GaP. An increase (P <0.0001) in NH3-N concentration was recorded with 4 mg and 8 mg GaP compared with control, whereas adding 32 and 64 mg resulted in a NH3-N concentration equivalent to control (averaged 39.25 mg/100 ml). The propionate (C3) increased with doses and the highest proportion was noted with the addition of 8 mg GaP (P <0.001). The TOMD was similar for all the doses except for 64 mg GaP, where a slight but significant (P <0.001) increase was noted (77.7%). GaP did not affect PF and MBM values until the dose of 64 mg. It was concluded that GaP added to a ration composed of 50% roughages and 50% concentrate did not result in drastic modifications of in vitro rumen fermentation parameters, except at the highest dose (64 mg), where an increase of gas production, TODM, PF and MBM were noted.Keywords: Ammonia-nitogen, garlic powder; gas production, microbial biomass, propionate, shee

Variación estacional y sexual en la composición y perfil de ácidos grasos en filetes de caballa, Scomber scombrus (L. 1758) de la costa este tunecina

This study investigates the impact of season and sex variations on the total lipid contents and fatty acid composition of Scomber scombrus fillets from the Middle East Coast of Tunisia in order to dertermine the most favorable periods for consumption, and to see if the nutritional quality of the meat depends on the sex of the animal. The effect of fishing season induced significant changes in the lipid profile, and the highest values for total lipids were obtained in the spring for females with 13.2% and for males with 18.9%. The highest values for proteins were obtained in the summer for females with 22.0% and for males with 21.8%. Protein content variations were not significant (p > 0.05). The n-3/n-6 ratio showed a significant level, indicating a tendency toward n-3 fatty acid accumulation in mackerel fillets mainly represented by DHA, whose values were high during the study period for both sexes, except in autumun, which is the period of mackerel gonad maturation, when DHA decreased significantly (p 0.05). The Atherogenicity index (AI) and Thrombogenicity index (TI) were calculated. In our study the AI index was comprised between 0.3 and 0.6 for males and between 0.4 and 0.5 for females. The TI index values ranged from 0.6 to 0.8 for males, and was about 0.6 for females.Este estudio investiga el impacto de las variaciones estacionales y sexuales sobre el contenido total de lípidos y la composición de ácidos grasos de filetes de caballa, Scomber scombrus, de la Costa Este Tunecina, con objeto de determinar los períodos más favorables para su consumo y para ver si la calidad nutricional de la carne depende del sexo del animal. Los efectos de la temporada de pesca indujeron cambios significativos en el perfil de lípidos, así, los valores más altos de lípidos totales se obtuvieron en primavera para las hembras, 13,2% y para los machos, 18,9%. Los valores más altos de proteína se obtuvieron en verano para las hembras, 22,0% y para los machos 21,8%. Las variaciones en el contenido de proteínas no fueron significativas (

Strategy of Utilization of Locally Available Crop Residues and By-Products for Livestock Feeding in Tunisia

Important quantities of crop residues and by-products are yearly available in North African countries. This paper presents the screening of the most important by-products in Tunisia, their nutritional characteristics and the appropriate strategies to use most of them in order to improve ruminants feeding systems. One or several by-products are specifie of each region of the country but most of them are localized in the northern region. Some of the agricultural wastes are available in important quantities but are of nutritionally poor or moderate qualities (straw, olive wastes, poultry litter, etc), while others are produced in limited amounts but are of very interesting feeding values (sugar beet pulp, brewers grain, date residue, etc). The main applied strategies to valorize Tunisian agricultural by-products consist in ammoniation of cereal straws along with supplementation with multinutriment blocks and formulation of balanced diets based totally or partially on them. These alternatives are crucial in the improvement of feeding values of studied diets and animal performances essentially by improving micro-bial activity in the rumen. In Tunisia such solution could be applied both in extensive and moderate animal production systems

Estimation of Tunisian greenhouse gas emissions from different livestock species

17 páginas, 7 figuras, 3 tablas.This research was partly supported by the CLCA project, Phase II (Use of conservation agriculture in crop-livestock systems in the drylands for enhanced water use efficiency, soil fertility and productivity in NENA and LAC countries), which is funded by the International Fund for Agricultural Development (IFAD) (ICARDA's agreement No200116)