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71.
The frequencies of milk protein variants alphas1-casein, alphas2-casein, beta-casein and beta-lactoglobulin were determined in 182 milk sheep from 7 flocks in Lower Saxony and Saxony. The genotype effects of these polymorphic milk protein variants on milk performance traits were estimated for 173 ewes using a test day model with fixed regression.The model included the fixed effects of colour variant of the breed, region, lambing season, lambing year, lactation number and number of lambs born. The herd and animal effect were treated as random and the days in milk as linear and non-linear covariates. The milk protein variants of alphas1-casein and beta-casein showed a significant relationship to protein content and the variants of beta-casein to milk fat content. Milk fat yield was significantly associated with the milk protein variants of alphas2-casein, whereas the other milk performance traits were not significantly correlated.  相似文献   
72.
Two experiments were conducted to determine independent effects of BW and DE intake on body composition and the partitioning of retained body energy between lipid and protein in pigs with high lean tissue growth potentials and when energy intake limited whole-body protein deposition. In a preliminary N-balance experiment involving 20 entire male pigs at either 30 or 100 kg BW, it was established that whole-body protein deposition increased linearly (P < 0.05) with DE intake at both BW. These results indicate that DE intake controlled whole-body protein deposition and that these pigs did not achieve their maximum whole-body protein deposition when fed semi-ad libitum. In the main serial slaughter experiment, 56 pigs, with a BW of 15 kg, were assigned to one of four DE intake schemes and slaughtered at 40, 65, 90, or 115 kg BW. Within DE intake schemes, DE intake was increased linearly (P < 0.05) with BW, allowing for an assessment of effects of DE intake and slaughter BW on chemical and physical body composition (carcass, viscera, blood). Between 15 and 90 kg BW, average DE intake of 16.1, 20.9, 25.2, and 28.8 MJ/d supported average BW gains of 502, 731, 899, and 951 g/d, respectively. The proportion of whole-body protein present in the carcass increased with BW and decreased with DE intake (P < 0.05), whereas the distribution of whole-body lipid between carcass and viscera was not influenced by BW and DE intake. A mathematical relationship was developed to determine the relationship between DE intake at slaughter (MJ/d) and chemical body composition in these pigs: whole-body lipid-to-protein ratio = 1.236 - 0.056 x (DE intake) + 0.0013 x (DE intake)2, r2 = 0.71. The data suggests that absolute DE intake alone was an adequate predictor of chemical body composition in this population of entire male pigs over the BW and DE intake ranges that were evaluated, simplifying the characterization of this aspect of nutrition partitioning for growth in different pig populations.  相似文献   
73.
The objective of the present study was to evaluate the importance of genetic and environmental sources of variation for results of behaviour tests recorded at juvenile and breeding performance tests in the Hovawart dog. For these analyses behaviour test results of 1882 (juvenile evaluation), respectively 929 dogs (breeding performance test) born in 1995 to 2000 had been used. Variance component estimation was performed for the traits appearance, play instinct, hunting affinity, group of people, shoot, acoustical and optical influences and temperament using multivariate linear animal models and Residual Maximum Likelihood (REML). The models included test-year-season, sex, litter size, age and inbreeding coefficient of the animal as fixed effects. Additive genetic effects of the animal, permanent environmental effect of the litter and the effect of the kennel were considered as random factors.The sex of the dog was significant for appearance, play instinct, hunting affinity, acoustical and optical influences of juvenile evaluation and for the traits temperament, play instinct, hunting affinity, acoustical and one of the optical influences of breeding performance test.The age of the dog at test significantly influenced the traits play instinct, hunting affinity and acoustical influences of juvenile evaluation and optical influences and hunting affinity of breeding performance test. All traits with exception of hunting affinity and group of people were significantly affected by the test-year-season. The inbreeding coefficient was significant for appearance of juvenile evaluation and play affinity of breeding performance test. The effect litter size did not influence any of the traits significantly.The estimated heritabilities for the behaviour traits of juvenile and breeding performance test ranged from h2 = 0.01 to h2 = 0.13, respectively h2 = 0.01 to h2 = 0.14, with standard errors of up to 0.03. The additive genetic correlations between most of the traits were moderately to highly positive (r(g) = 0.20 to r(g) = 1.0, respectively r(g) = 0.29 to r(g) = 1.0). Negative additive genetic correlations were only found for a few traits of juvenile (r(g) = -0.02 to r(g) = -0.58) and breeding performance test (r(g) = -0.28 to r(g) = -0.83). Progress in breeding for the behaviour traits investigated here may only be meaningful when information from all relatives is used in an animal model instead of selection based on the phenotype of the single animal.  相似文献   
74.
To determine the effect of dietary inclusion level of wheat shorts (WS; a high nonstarch poly-saccharide-containing feed ingredient) and casein (CS; a control) on the efficiency of utilizing ileal digestible Lys (kLys) and Thr (kThr) for whole body protein deposition (PD) in the growing pig, 2 separate N-balance studies were conducted with either Lys or Thr as first-limiting AA in cornstarch-based diets. For the Lys study, a basal diet (L-basal) was formulated to contain 0.24 g of standardized ileal digestible (SID) Lys per MJ of DE, to which 0.095 or 0.19 g of SID Lys per MJ of DE were added using either CS (L-CS2 or L-CS3, respectively) or WS (L-WS2 or L-WS3, respectively). A sixth diet was evaluated that was similar to L-CS3 but to which 6% pectin (L-pectin) was added as a source of soluble nonstarch polysaccharides. For the Thr study, the basal diet (T-basal) was formulated to contain 0.14 g of SID Thr per MJ of DE, to which 0.055 or 0.11 g of SID Thr per MJ of DE were added from CS (T-CS2 or T-CS3, respectively) or from WS (T-WS2 and T-WS3, respectively). A sixth diet was evaluated that was similar to T-CS3 but to which 6% pectin was added (T-pectin). Increasing SID Lys intake from CS did not influence kLys for PD (P > 0.10), whereas increasing SID Lys intake from WS reduced kLys for PD (P = 0.001; 89 vs. 79%). Inclusion of 6% pectin had no effect on kLys for PD (P > 0.10). Increasing SID Thr intake from CS also did not influence kThr for PD (P > 0.10), whereas kThr for PD was reduced at the greatest dietary inclusion level of WS (P < 0.001; 90 vs. 77%). Pectin inclusion had no effect on kThr for PD (P > 0.10). The inefficiency of utilizing ileal digestible Lys intake for PD may be attributed to nonreactive Lys in WS. The negative impact of including high levels of WS in the diet of pigs on kThr seems to be associated with fiber content of WS; it was not related to increased endogenous ileal AA losses at the distal ileum. The impact of dietary AA source on the use of ileal digestible Lys and Thr for PD, or other body functions, is substantial and should be considered in the formulation of pig diets. Further research is warranted to elucidate the mechanisms contributing to substantial dietary effects on Thr use for PD.  相似文献   
75.
Use of dietary AA in growing pigs reflects digestion and use of digested AA for various body functions. Before evaluating dietary effects on use of digestible AA intake for body protein deposition, a digestibility study was conducted to investigate true ileal AA digestibility and endogenous ileal AA losses in growing pigs fed graded levels of wheat shorts (WS) or casein (CS; control). A casein-based basal diet (basal) was formulated to contain 0.27 g of standardized ileal digestible (SID) Lys per MJ of DE, to which extra Lys was added from WS (WS2, +0.10 g of SID Lys per MJ of DE; WS3, +0.20 g of SID Lys per MJ of DE) or casein (CS3, +0.20 g of SID Lys per MJ of DE). A fifth diet was formulated to be similar in CP level and source as CS3 but in which 6% pectin, a source of soluble non-starch polysaccharides (NSP), was included at the expense of cornstarch (CS3 + pectin). Five Yorkshire barrows (17.5 +/- 1.5 kg of BW) were fitted with a T-cannula at the distal ileum and randomly assigned to 1 of the 5 experimental diets in a 5 x 5 Latin Square design. Apparent ileal digestibility (AID), true ileal digestibility (TID), and endogenous ileal protein losses (EPL) were determined using the homoarginine method. Diet CS level did not influence (P > or = 0.10) TID of most essential AA or EPL (10.4 g/kg of DM intake). Including pectin in the diet did not influence TID of AA (P > or = 0.10) but increased EPL (15.6 g/kg of DM intake; P > or = 0.01). Inclusion of WS in the diet reduced TID of most essential AA (P < 0.01). The TID values for most essential AA, however, were the same (P > or = 0.10) for both dietary WS levels, except for Lys and Met, which were further reduced at the greatest dietary WS level. Increased EPL (P < 0.01) was only observed for WS3 (16 g/kg of DMI). We concluded that (1) the effects of dietary protein source on AID of AA can be attributed both to reduced TID of AA and increased EPL, (2) the impact of dietary WS level on TID of AA and EPL does not seem to be linear, (3) soluble NSP from pectin or WS exerts a greater effect on EPL than insoluble NSP, and (4) because of the metabolic cost associated with EPL and the impacts of feed composition on microbial fermentation in the gut lumen, the effects of feed ingredients on the use of ileal digestible AA for protein deposition should be investigated further.  相似文献   
76.
The Mycoplasma hyopneumoniae genome contains at least 22 regions with a variable number of tandem nucleotide repeats (VNTRs) within coding DNA sequences (CDSs). In this work, the VNTR-containing CDSs were analysed in order to evaluate their degree of variation, possible correlations with antigenic properties, and their potential to be used as a basis for a strain typing PCR assay. We have analysed the VNTRs in five M. hyopneumoniae strains (J, 7448, 7422, PMS, and 232), based on published genomic sequences and on amplified and sequenced DNA segments. These VNTRs are distributed among 12 genes, most of which encode putative surface proteins, including known adhesins. The number of repeat units in any of the VNTRs is highly variable among the analysed strains, but they are, without exception, translationally in frame, and, therefore, code for a variable number of aminoacid repeats (VNTARs). These VNTARs determine putative structural, physicochemical and antigenic variations in the corresponding proteins, with potential implications for aspects associated to M. hyopneumoniae pathogenicity, such as cell adhesion and interactions with the host immune system. Considering that the characterized VNTARs are relatively stable, at least in vitro, and their sizes are strain-specific, we have developed a VNTR-based PCR assay for M. hyopneumoniae strain identification, useful for enzootic pneumonia (EP) diagnosis, strain typing, and distinction of circulating field isolates from vaccine strains in animals vaccinated against EP.  相似文献   
77.
Natural dihydrocoumarin, which is of great interest in the flavor industry, was biotechnologically produced from pure coumarin or tonka bean meal with Pseudomonas orientalis, Bacillus cereus, and various Saccharomyces cerevisiae strains. Coumarin was shown to be converted to melilotic acid, which yielded dihydrocoumarin upon distillation during purification. About 1.0 g/L product was obtained from 25 g/L tonka beans with S. cerevisiae within 147 h. This dihydrocoumarin thus fulfills all of the criteria of a natural raw material and can be used as a natural flavoring in accordance with U.S. and European Union regulations.  相似文献   
78.
Elementary chemistry distinguishes two kinds of strong bonds between atoms in molecules: the covalent bond, where bonding arises from valence electron pairs shared between neighboring atoms, and the ionic bond, where transfer of electrons from one atom to another leads to Coulombic attraction between the resulting ions. We present a third, distinct bonding mechanism: perpendicular paramagnetic bonding, generated by the stabilization of antibonding orbitals in their perpendicular orientation relative to an external magnetic field. In strong fields such as those present in the atmospheres of white dwarfs (on the order of 10(5) teslas) and other stellar objects, our calculations suggest that this mechanism underlies the strong bonding of H(2) in the (3)Σ(u)(+)(1σ(g)1σ(u)*) triplet state and of He(2) in the (1)Σ(g)(+)(1σ(g)(2)1σ(u)(*2)) singlet state, as well as their preferred perpendicular orientation in the external field.  相似文献   
79.
Denileukin Diftitox (ONTAK®, DAB389 IL-2) is a recombinant DNA-derived fusion protein depleting cells that express high-affinity IL-2 receptor. Important cell targets are CD4+CD25+Foxp3+ regulatory T cells (Treg). Elimination of immunosuppressive Treg by Denileukin Diftitox may provide a way to modulate immune tolerance following stem cell transplantation. Here, we combined Treg depletion with a vaccination approach to induce donor-specific immune reactions. To investigate this approach we chose the mixed chimerism canine stem cell transplantation model which represents a high state of tolerance between two hematopoietic systems. The aim was therefore to induce a graft versus hematopoiesis effect thereby converting mixed to full donor chimerism. Dog leukocyte antigen identical siblings that had developed a stable mixed chimerism after non-myeloablative stem cell transplantation received a single dose of Denileukin Diftitox (18 μg/kg, i.v.) followed by several cell-lysate vaccinations. Host peripheral blood mononuclear cell lysates combined with CpG-ODN, and Montanide® ISA 51 were locally applied. In vitro studies demonstrated that canine Treg are a target of Denileukin Diftitox. The suppression of T-cell proliferation by Treg was abolished by addition of Denileukin Diftitox (10 nM). An increase of proliferation of median 300% (range: 200%–425%) was observed. No change in donor chimerism was observed after administration of Denileukin Diftitox and vaccination. This study highlights that application of Denileukin Diftitox resulted in a depletion of Treg followed by an increase of immune response in vitro. This effect could not be confirmed in vivo even if the immune system was stimulated by vaccinations.  相似文献   
80.
ABSTRACT: Classical Swine Fever (CSF) is considered an endemic disease in European wild boar populations. In view of the high economic impact of the introduction of the virus into domestic pig units, huge efforts are invested in the preventive control of CSF in wild boar populations. Recent European Community guidelines favour oral mass vaccination against CSF in wild boar populations. The guidelines are explicit on the temporal structure of the vaccination protocol, but little is known about the efficacy of different spatial application schemes, or how they relate to outbreak dynamics.We use a spatially explicit, individual-based wild boar model that represents the ecology of the hosts and the epidemiology of CSF, both on a regional scale and on the level of individual course of infection. We simulate adaptive spatial vaccination schemes accounting for the acute spread of an outbreak while using the temporal vaccination protocol proposed in the Community guidelines.Vaccination was found to be beneficial in a wide range of scenarios. We show that the short-term proactive component of a vaccination strategy is not only as decisive as short-term continuity, but also that it can outcompete alternative practices while being practically feasible. Furthermore, we show that under certain virus-host conditions vaccination might actually contribute to disease persistence in local populations.  相似文献   
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