1. An experiment was conducted to compare the relative bioefficacy of DL‐methionine hydroxy analogue free acid (DL‐MHA‐FA) with DL‐methionine in broiler chickens. Responses used for comparison were weight gain and food efficiency between 7 and 35 d of age, and breast meat deposition, food cost per kg of breast meat, and abdominal fat at 41 d of age.
2. A total of 2160 seven‐day‐old male broiler chicks were used. The feeding programme consisted of a starter diet from 7 to 21 d, and a finisher diet till the end of the experiment. The starter basal diet contained 6.1 g/kg total sulphur‐containing amino acids (TSAA), and an estimated metabolisable energy (ME) content of 13.2 MJ/kg. The finisher diet contained 5.8 g/kg TSAA and an estimated ME content of 13.6 MJ/kg. Four concentrations of DL‐methionine and DL‐MHA‐FA were added at 0.5g/kg increments on an equimolar basis. Therefore, there were 9 experimental treatments which were each applied to 6 replicates of 40 chicks. Weight gain and food efficiency were determined at 35 d of age. Breast yield and carcase fat were measured at 41 d.
3. Significant responses to graded amounts of both methionine sources were observed in weight gain, food efficiency, breast meat percentage, and food cost per kg of breast meat. The responses fitted exponential regression curves. Based on the regression coefficients, equimolar bioefficacy of DL‐MHA‐FA relative to DL‐methionine was 80% for daily gain, 83% for food efficiency, 51% for breast meat yield, and 66% for food cost per kg of breast meat. Differences between the 2 sources were significant (P< 0.05) for breast meat yield and food cost per kg of meat and (P< 0.10) for food efficiency. 相似文献
1. The effect of three metabolisable energy (ME) concentrations 12.2, 11.3 and 10.5 MJ ME/kg and two forms of diet (mash and pellet) on egg production in summer and winter were studied. The different ME values were obtained by diluting the 12.2 MJ ME/kg diet with sugar beet pulp of 2.88 MJ/kg DM. In a 3rd summer experiment the water intake of hens on these diets was examined. Data were analysed by factorial analysis of variance, and the relationship between performance and dietary energy concentration was examined by regression analysis.
2. The use of low energy diets (10.5 to 11.3 MJ ME/kg) decreased egg production in both seasons, but pelleting diets improved egg production and egg weight in summer. Egg weight was not affected by energy density in winter, but decreased in the summer when energy density increased.
3. In winter, food consumption was not affected by the dietary ME, while in summer food consumption increased when the dietary ME increased. Therefore, energy intake was not the same at all energy densities, but tended to increase as the energy density increased.
4. In summer, pelleting improved food efficiency and egg production and increased water consumption and the ratio of water to food intake. Water intake and water: food ratio decreased with increasing dietary energy concentration. 相似文献
Based on the scarcity of reports in veterinary medicine literature, it appears that Arcanobacterium spp. are rarely isolated from horses. Recently, a single isolate from vaginal discharge in a mare was characterized as a new species, Arcanobacterium hippocoleae. The present report describes a case of necrosuppurative placentitis and stillbirth in an American Quarterhorse mare. Numerous colonies of irregular, Gram-positive, rod-shaped bacteria were observed by histological examination within fibrin lattice associated with placental lesions. Arcanobacterium hippocoleae was isolated in large numbers from the placenta, lung, and stomach contents. To the authors' knowledge, this is the first report of placentitis associated with Arcanobacterium spp. in a horse and the third reported isolation of A. hippocoleae from a horse. 相似文献
A die-off occurred in a captive colony of blue-winged grasshoppers (Tropidacris collaris) at the Toronto Zoo. One fourth of the colony died within a year due to infection with worms initially mistaken for nematomorphs but later identified as nematodes belonging to the Mermithidae, genus Mermis. Mortality persisted and the grasshopper population dwindled over the following years. Mermithid larvae developed in the hemocoel of the insects until they eventually emerged from a hollowed-out exoskeleton. Circumstantial evidence suggests that the parasites were introduced with raspberry browse that was grown on site and contaminated with mermithid eggs. 相似文献
Eighty-four olive accessions obtained from the National Conservatory of Boughrara-Sfax (Tunisia), previously evaluated for morphological traits, were analysed with 47 random amplified polymorphic DNA (RAPD) markers. They were compared with other olive genotypes originated from Eastern or Western Mediterranean. The highest and lowest similarities between genotypes, estimated by simple matching algorithm, were 0.98 and 0.40, respectively. A dendrogram based on Ward's method and a factorial correspondence analysis (FCA) showed that most of Tunisian accessions are closely related to olive genotypes originating from the Eastern Mediterranean and some are clustering with genotypes originated from the Western Mediterranean. These findings suggested multiple and complex origin of Tunisian olive. A comparative study between a previous morphological analysis and current RAPD assay was carried out and discussed. 相似文献
We investigated whether high‐quality in vitro matured (IVM) oocytes can be distinguished from poor ones based on the morphological changes after treatment with hyperosmotic medium containing 0.2 mol/L sucrose in pigs. We hypothesize that IVM oocytes maintaining round shape have higher quality than mis‐shapened oocytes following dehydration. Oocyte quality was verified by determining embryonic developmental competence using in vitro fertilization, nuclear transfer and parthenogenetic activation. In all cases, the round oocytes had greater (p < .05) developmental competence than that of mis‐shapened oocytes in terms of blastocyst rate and total cell number in blastocysts obtained after 6 days of in vitro culture. We also confirm that round aged oocytes are higher in quality than mis‐shapened aged oocytes. In an attempt to find out why high‐quality oocytes maintain a round shape whereas poorer oocytes become mis‐shapened following sucrose treatment, we examined the arrangement of actin microfilaments and microtubules. Abnormal organization of these cytoskeletal components was higher (p <.05) in mis‐shapened oocytes compared to round oocytes after 52 hr of IVM. In conclusion, sucrose treatment helps selection of high‐quality oocytes, including aged oocytes, in pigs. Abnormal cytoskeleton arrangements partly explain for low developmental competence of mis‐shapened oocytes. 相似文献
Ultimate pH (pHu) is a major determinant factor of meat quality. In this study, we investigated the effects of pHu on the muscle antioxidant capacity, and the relationship between pHu and muscle antioxidant capacity of pigs. A total of 137 pigs from three pig breeds with the same feeding condition were slaughtered and used to measure the pHu, superoxide dismutase (SOD), glutathione peroxidase (GSH‐PX), total antioxidant capacity (T‐AOC), and malondialdehyde (MDA) content, and gene expression of SOD1 and GPX4. Loins from 137 pigs of three breeds were classified based on pHu into three groups: low (L‐pH: ≤5.50), intermediate (I‐pH: 5.51‐5.90), and high (H‐pH: ≥5.91). A majority of loins (47.5%–52%) were classified into the intermediate group. The results suggested that the pHu value was correlated with the activity of SOD, GSH‐PX, T‐AOC, and MDA, and gene expression of SOD1 and GPX4 in all pigs. In addition, our results also indicated a linear relationship between the pHu value and antioxidant traits. The pHu value accounted for 23%–40% of the variation in the antioxidant traits. These results suggested that increased pHu reduce the lipid peroxidation, and also indicated that pHu may be a key factor explaining the variation in the activity of antioxidant enzymes and gene expression in pork loins. 相似文献
The effect of chopping time and heating on physicochemical properties of meat batters was investigated by low‐field nuclear magnetic resonance and rheology technology. Cooking loss and L* increased while texture profile analysis index decreased between chopping 5 and 6 min. The relaxation time T21 (bound water) and its peak area ratio decreased, while the ratio of T22 peak area (immobilized water) in raw meat batters gradually increased with the extension of chopping time. However, T22 was opposite after being heated and a new component T23 (free water) appeared (T2i is the spin – spin relaxation time for the ith component.). The initial damping factor (Tan δ) gradually decreased and there were significant difference between 4 and 5 min of chopping time. There were significantly positive correlations between the ratio of peak area of T22 and chopping time, the storage modulus (G′), cooking loss, and L*, respectively. Continued chopping time could improve the peak area proportion of T22 in raw meat batters. Further, the higher the peak area proportion of T22 in raw meat batters, the cooking loss of heated meat gel was higher. Also, the stronger the mobility of immobilized water in meat batter, the higher the L* of the fresh meat batters. Thus, it is revealed that the physicochemical properties of meat batter are significantly influenced by chopping time which further affects the water holding capacity and the texture of emulsification gel. 相似文献