Mycobacterium avium paratuberculosis is the causative agent of Johne disease, a chronic ulcerative intestinal condition in ruminant animals. Owing to the predominance
of cellular response in subclinical forms of the infection, identification of M. a. paratuberculosis antigens eliciting host cell-mediated immune (CMI) reaction is crucial for early control of the disease. A 35 kDa protein
of M. a. paratuberculosis was studied for its ability to elicit CMI responses using a mouse model. Lymphoproliferation and IFN-γ response were used
to measure the CMI response. Recombinant 35 kDa protein (P35) stimulated proliferation of mouse mononuclear splenocytes sensitized
with M. a. paratuberculosis. The P35 elicited increased nitrite production from mononuclear splenocytes from M. a. paratuberculosis-sensitized
mice. In addition, RT-PCR-based semiquantitative IFN-γ measurement showed that stimulation with P35 is associated with significant
expression of IFN-γ mRNA in M. a. paratuberculosis-sensitized mouse splenocytes. The results indicate that the 35 kDa protein
of M. a. paratuberculosis is associated with CMI response in the host. 相似文献
Fifteen adult crossbred cattle bulls, 18-22 months old (mean body weight 286.33 + 9.43) were divided into 3 groups following RBD design and were fed sugarcane tops (SCT) supplemented with some agro-industrial
byproducts and concentrate feeds to determine nitrogen, Ca and P in crossbred cattle bull. For this purpose, crossbred cattle
bulls were fed for 30 days ad lib SCT supplemented with Wheat bran (WB), Lentil chuni (LC) and WB + LC (50:50) in Group I, II, and III respectively. The balance
values were 15.28 + 2.70, 26.85 + 4.35 and 18.00 + 3.17 for nitrogen, 11.77 + 1.34, 12.94 + 2.96 and 15.38 + 1.15 for calcium, 11.74 + 0.64, 11.26 + 1.58 and 11.69 + 0.79 for phosphorus in group I, II and III, respectively. There were no significant differences among the experimental groups
in Ca and P balance values but balance of nitrogen was significantly (P < 0.05) higher in group II as compared to group I
and III. It may indicated that the rumen fermentation was more appropriate in group III where animals were fed 50% lentil
chuni and 50% wheat bran (supplementation of both protein and energy). 相似文献
1.?An experiment (21 d) was conducted to determine if the response of chicks to a cocktail of xylanase, amylase, and protease (XAP) or Escherichia coli-derived phytase individually or in combination when fed a nutritionally marginal maize–soybean meal diet is age-dependent.
2.?A total of 250 one-day-old Ven Cobb broiler chicks were allocated to 5 dietary treatments in a randomised complete block design. The treatments were as follows: (1) positive control with supplemental inorganic P; (2) negative control (NC) marginal in P and ME; (3) NC plus XAP to provide (per kg of diet) 650, 1650 and 4000 U of xylanase, amylase, and protease, respectively; (4) NC plus phytase added to provide 1000 phytase units/kg; and (5) NC plus a combination of XAP and phytase.
3.?Low ME and P in the NC diet depressed weight gain and gain:feed. A cocktail of XAP alone did not improve performance, but phytase supplementation improved weight gain. The enzymes were additive in their effects on growth performance.
4.?The enzymes had no effect on ileal digestible energy. Ileal N digestibility was higher in diets with XAP or phytase individually compared with NC. Both phytase and XAP individually and in combination improved ileal P digestibility compared with NC.
5.?Total tract nutrient retention and ME increased as the birds grew older. There were age × diet interactions in total tract retention of P and Ca; improvement in P retention due to phytase use decreased by 50% as the chicks matured.
6.?The current study shows that a combination of XAP and phytase improved performance, but the enhancement in performance appears to be due mainly to phytase. Both XAP and phytase were effective in improving P digestibility and retention of chicks receiving nutritionally marginal maize–soybean meal.
7.?The data also showed that the chicks benefited more from the enzyme addition at a younger age and that the contribution of the enzymes to nutrient retention decreased with age in chickens. 相似文献
Brucellosis not only represents an important health restraint on livestock but also causes high economic losses in many developing countries worldwide. Despite considerable efforts made for the control of brucellosis, the disease is still spreading in many regions (such as the Middle East) where it represents one of the most important health hazards impacting both animals and humans. The present review aims to investigate the efficacy of veterinary control programs regarding brucellosis, with a special focus on current prevention, control, and eradication approaches. The reasons for unsuccessful control programs such as the absence of highly effective vaccines and non-certified bulls are also debated, to understand why the prevalence of brucellosis in livestock is not decreasing in many areas despite considerable efforts taken to date. The importance of governmental and regional investment in brucellosis control remains one of the main limiting factors owing to the limited budget allocated to tackle this disease. In this context, one health concept has generated novel comprehensive approaches with multiple economic implications across the livestock industry and public health. However, the implementation of such global preventive strategies appears to be a key issue for many endemic and low-income countries. According to the collected data, epidemiological contexts including management and trade systems along with well-defined agro-ecological zones should be evaluated in brucellosis endemic countries to improve milk production and to enhance the sustainability of the livestock sector at both national and regional levels. 相似文献
The present study reports that protoplasts isolated from stoloniferous shoots (SS) of potato represent an efficient system for somatic cell genetic manipulations. SS were established from single-node cuttings on MS medium supplemented with either 0.1 or 0.2 M sucrose (Suc), and protoplasts were isolated and cultured within the alginate strip, following an improved method. SS induced by 0.1 M Suc yielded 8–22 × 105 protoplasts g−1 fresh mass, with a high morphogenic competence. However, 0.2 M Suc-induced SS yielded protoplasts that contained large amounts of starch grains, resulting in their high degree of fragility, delayed cell division and poor morphogenic competence. For symmetric somatic hybridization (electrofusion) between Solanum tuberosum Gp. Tuberosum androgenic (di)haploid (2n = 2x = 24) ‘C-13’ and diploid (2n = 2x = 24) wild species S. pinnatisectum, protoplasts isolated from 0.1 M Suc-induced SS were also found to be most responsive. Out of several putative somatic hybrids, there were two tetraploids and five diploids, with 48 and 24 chromosomes, respectively at all the three shoot layers (L1–L3). This precluded the occurrence of mixoploidy vis-à-vis chimaerism in regenerants, as common in somatic fusion involving mesophyll protoplasts of S. pinnatisectum. Nuclear microsatellite analyses based on the two single-locus nSSR loci (STM0037 and STM2030) confirmed that one of the tetraploids was a true nuclear hybrid (heterokaryon), while the other a homokaryon of the Tuberosum parent ‘C-13’. The use of 0.2 M Suc-induced SS protoplasts for fundamental studies on tissue- and/or cell type-specific transient gene expression underlying tuberization has been discussed. 相似文献
Immune interferon gamma (IFN-γ) is essential for mammalian host defense against intracellular pathogens. IFN-γ induces nearly 2000 host genes, yet few have any assigned function. Here, we examined a complete mouse 65-kilodalton (kD) guanylate-binding protein (Gbp) gene family as part of a 43-member IFN-γ-inducible guanosine triphosphatase (GTPase) superfamily in mouse and human genomes. Family-wide loss-of-function analysis found that at least four Gbps--Gbp1, Gbp6, Gbp7, and Gbp10--conferred cell-autonomous immunity to listerial or mycobacterial infection within macrophages and gene-deficient animals. These Gbps solicited host defense proteins, including the phagocyte oxidase, antimicrobial peptides, and autophagy effectors, to kill intracellular bacteria. Thus, specific 65-kD Gbps coordinate a potent oxidative and vesicular trafficking program to protect the host from infection. 相似文献
The availability of effective inoculant rhizobia is often critical to the successful development of productive forage legumes. Biserrula pelecinus L. is a legume with potential as forage in Ethiopia to improve livestock feed quality and soil fertility. B. pelecinus can form N2‐fixing symbiosis with rhizobia in the genus Mesorhizobium. This study investigated the N2 fixation effectiveness of 15 B. pelecinus‐nodulating Mesorhizobium strains on two subspecies of B. pelecinus (B. pelecinus ssp. leiocarpa, native to Ethiopia, and the introduced B. pelecinus ssp. pelecinus). The most effective strain (WSM3873) on both subspecies was assessed at two sites; one with pre‐existing populations of B. pelecinus‐nodulating rhizobia (Modjo), and one without (Holeta). No inoculation response was observed at Modjo when B. pelecinus ssp. pelecinus was inoculated with WSM3873 alone, however, biomass yield was greatest (11.5 tonne DM/ha) following inoculation along with co‐application of phosphorus and nitrogen. At Holeta, a strong inoculation response was achieved with WSM3873 alone on B. pelecinus ssp. pelecinus. In contrast, B. pelecinus ssp. leiocarpa did not show any response at Modjo and failed to emerge after sowing at Holeta. While the native legume B. pelecinus ssp. leiocarpa appears poorly suited to development as a forage, B. pelecinus ssp. pelecinus and WSM3873 represents a promising legume‐rhizobia symbiosis that could benefit farming systems of the central Ethiopian highlands. 相似文献