Egg shell breakage accounts for a loss of 7 to 8% of the total eggs laid. Because shell breakage is related to egg shell strength, numerous methods have been developed to measure shell strength in relation to egg breakage. These methods can be divided into those that measure shell strength indirectly and those that measure directly. Egg specific gravity, nondestructive deformation, and beta backscatter are examples of indirect methods and quasi-static compression fracture, impact fracture, and puncture force are examples of direct measurements. A major advantage with indirect methods is that multiple measurements of shell strength may be taken on the same egg and the egg may be subsequently hatched, whereas with the direct methods the shell is fractured during the measurement. Factors known to influence the measurement of shell strength include the temperature of eggs, the length of time between oviposition and measurements, the sequence in which indirect measurements are taken, the compression rate and response time of recording equipment used to measure deformation, compression fracture and puncture force, the configuration and roughness of the surfaces of the measuring equipment that contact the egg shell, the deformation within the measuring equipment, and possibly the moisture content of the shell. Details of these factors should be reported with shell strength data. In general, there is a moderate relationship (r<.75) between data from indirect and direct shell strength measurements. There is a curvilinear relationship between shell strength and egg shell breakage. Further research is required to determine which of die indirect or direct methods best predict shell breakage under field conditions and to develop a model that will explain the strength of the hen's egg shell.(Key words: egg shell strength, egg shell breakage, measurement methods, specific gravity, nondestructive deformation, beta backscatter, compression fracture force, impact fracture force, puncture force) 1982 Poultry Science 61:2022-2039The measurement of egg shell strength has 2022

No abstract

During the summer of 1980, there was a great deal of rainfall and high humidity in southwestern Ontario. Sprouting of the kernels on plants in the field and pink discoloration down-graded the white winter wheat crop. Samples were submitted to Agriculture Canada from elevators and boats loading wheat for export. Chemical analyses indicated low levels of vomitoxin, with some analytical results as high as 8.5 ppm. A series of feeding trials was initiated with contaminated wheat (1.0 ppm vomitoxin) to determine effects on swine and poultry. Swine diets containing 0.3 and 0.7 ppm vomitoxin resulted in decreased feed consumption and weight gains. Poultry were fed similar levels of vomitoxin without any serious effects. Gross examination of internal organs at the termination of the subacute studies revealed no apparent toxic effects. Several farmers reported feed refusal, vomiting and death in their livestock. Chemical analyses, in general, revealed relatively low levels of vomitoxin. In one case, the level of vomitoxin (0.95 ppm) in the feed was high enough to he a possible contributing factor in the observed ill effects.

No abstract

(169,211, 2i3 and287 d) and at five times during the test day (0800, 1000, 1200, 1,100 and 1600 h) were performed. Egg lipids were analyzed at each of the four periods.Pllrtnu total lipids were inversely related (P < 0.01) to dietary HM levels while omega-3 and omega-6 fatty acid levels were positively and inversely related (P < 0.001), respectively. HM levels did not influence the total lipid content of the egg yolk iipid. boi o-.ga-3 and omega-6 fany acid content w;re positively and inversely related, respectively. The lwels_ of eicosapentaglgig (20:Sn:,epn) and docosahlxae11oic (22:6I3,DHA) a;id were 1l and 3 times higher, respectively (7.8 and 100.5 mg yolk-') in the yolks from hens given the l27o HM diet compared to the control diet.Key words; Herring meal, laying hens, omega-3 fatty acids, eicosapentaenoic acid, docosahexaenoic acid Nash, D. M., Hamilton Dietary HM lowered the omega-6 (P < 0.001) and increased the omega-3 fatty acid content (P < 0.001) of the plasma lipids (Table 4), thus lowering the plasma n6/n3 ratio from7.7 to a more beneficial 3.7 (Surgeon General's Report 1988). The major fatty acids responsible for the above change were palmitic (16:0), oleic (18:1n9), linoleic (18:2n6), arachidonic Q0:4n6), eicosapentaenoic (20:5n3) and docosahexaenoic (22:6n3) (Table 5). There was a genotype x diet interaction for 16:0, but no trends were evident. The difference (P < 0.05) in the levels of these plasma fatty acids between genotypes indicated genetic variation between the two commercial stocks of laying hens. With the l2Vo HM diet, the plasma EPA (20:5n3) and DHA (22:6n3) levels (0.29 and 2.73 'xtl7o, Table 5) were lower than the EPA and DHA levels (1.3 and 3.8 wtl%) observed by Cherian and Sim (1991) who fed a diet that contained 16% flaxto SCWL layers. The levels of EPA and DHA reported herein were There was a linear (P < 0.001) relation between EpA and DHA levels in the plasma and dietary levels of HM (Table 6) showing a typical dose response relationship. The change over time for genorype (P < 0.05), suggested that this response was less for DHA as time increased (Table 6). *,**,***SignificantatP<0.05,P<0.01andp<0.00l,respectively;NS,nonsignifrcant(p>0.05). x'**'***signiflcantatP<0.05,P<0.0landp<0.00l,respectively;NS,nonsignificant(p>0.05).