The effect of soybean soapstock on the quality parameters and fatty acid composition of the hen egg yolk.

The effects of increasing proportions of soybean soapstock (SSS) in laying hen diets on egg quality parameters and on the fatty acid (FA) composition of the yolk were studied. One hundred sixty Babcock B-300 x laying hens, 20 wk of age, were allotted to 5 dietary treatments comprising a control diet (D5) with soybean oil at 100% or SSS in proportions of 25% (D1), 50% (D2), 75% (D3), and 100% (D4) replacing the oil source in commercial-type diets throughout the 15-wk laying period. Egg quality parameters were recorded weekly. Four pooled yolks for each treatment were collected at 0, 9, and 15 wk, and their FA profiles were determined. Egg weight, shell thickness, shape index, and Haugh unit were not influenced by dietary treatment. The concentrations of saturated FA (SFA) in yolks were generally kept at a constant level, regardless of the percentage of SSS in the hen diets. Total monounsaturated FA (MUFA) content did not vary over the course of the experiment, except for C14:1. After 15 wk of feeding, the total polyunsaturated FA (PUFA) n-3 increased in yolks of all diets. Among the long-chain PUFA, the percentage of C20:4 (arachidonic acid) was less affected. Inclusion of 100% SSS allowed production of eggs with similar PUFA/SFA and n-6/n-3 ratios when compared with eggs from hens fed D5. As SSS represents one-third of the oil cost, its inclusion in layer diets could represent an important economic benefit.

Organochlorine pesticide residues in cow's milk from a tropical region of Mexico.

A monitoring study was conducted to assess the magnitude of DDT [(1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane)] and HCH (hexachlorocyclohexane) contamination of bovine milk from the central tropical region of Mexico as the chemicals are extensively used in livestock and public-health programmes. Among pesticide residues analysed, the milk samples collected from Tlalixcoyan showed a mean level of gamma-HCH (0.128 mg x kg(-1)), which was significantly higher than residues in milk samples from Medellin (0.049 mg x kg(-1)) and Paso San Juan (0.022 mg x kg(-1)). The mean level of pp'-DDE in Medellin samples (0.039 mg x kg(-1)) was significantly higher than in Paso San Juan (0.018 mg x kg(-1)) and Tlalixcoyan (0.024 mg x kg(-1)) milk samples. The pp'-DDT mean level from Medellin milk samples (0.089 mg x kg(-1)) was significantly higher than the levels detected in the other two areas. The highest mean Sigma-DDT level detected in Medellin samples (0.146 mg x kg(-1)) was three times the FAO/WHO tolerance level. The highest acceptable daily intakes calculated for Sigma-DDT were 0.017 microg x kg(-1) bw day(-1) for adults and 0.530 microg x kg(-1) bw day(-1) for infants; for gamma-HCH residues, they were 0.021 microg x kg(-1) bw day(-1) for adults and 0.666 microg x kg(-1) bw day(-1) for infants, indicating that infants are more exposed to pesticide residues. Results indicate that cattle exposure to HCH and DDT results in high levels in dairy milk and a potential health risk for consumers.

Use of cholinesterase activity in monitoring organophosphate pesticide exposure of cattle produced in tropical areas.

The use of cholinesterase activity as a biochemical method for monitoring organophosphate pesticide exposure in cattle is described herein. Determination of cholinesterase activity of whole blood, erythrocyte, and plasma was carried out according to the Ellman modified kinetic method. The mean baseline acetylcholinesterase activities of 9.549 +/- 3.619 IU/mL in whole blood, 9.444 +/- 3.006 IU/mL in erythrocytes, and 0.149 +/- 0.063 IU/mL in plasma were estimated for steers from the control group. Results of multivariate analysis showed that the general responses between the control and experimental groups (in vivo, monitoring and case studies) treated with Coumaphos and Fenthion were statistically different, and the general responses of these experimental groups were statistically different over time as well. Among the fractions that were analyzed, the erythrocyte acetylcholinesterase activity could be adequate for the diagnosis of exposure or acute poisoning in cattle as it showed a good within-run and between-run precision with CVs <10% better than those in plasma.

The effect of acidified soapstocks on feed conversion and broiler skin pigmentation.

The effect of different soapstocks (corn, sunflower, canola, and soybean) on productive performance and skin broiler pigmentation was investigated. Soapstock was added to reach 1.0% polyunsaturated fatty acids in the diet. The addition of soybean soapstock significantly improved live body weight gain of the birds from 1 to 7 wk of age. A live body weight gain of 1,736 g/bird was calculated for broilers fed with the soybean soapstock diet. Feed conversion was significantly higher for broilers fed with the soybean soapstock diet, and no negative effect was observed. Compared to broilers fed with Pixtafil (100.0% pigmentation), those fed soybean soapstock (when added as a supplement of 1.0% polyunsaturated fatty acids in the diet) reached 48.0% pigmentation, and those fed corn soapstock reached only 7.3%. When the diets were complemented with Pixtafil to reach 100% of calculated pigmentation, the soybean soapstock diet reached 100.8% pigmentation compared to a canola soapstock diet that reached 72.0% pigmentation. Acidified soybean soapstock could be a source of polyunsaturated fatty acids and of xantophyl pigments in broiler feeding.

Organochlorine pesticide residues in cow's milk and butter in Mexico.

This monitoring study of 355 samples of cow's milk collected from the central region of Veracruz state and 448 samples of national butter brands was conducted to determine the contamination levels of organochlorine pesticides. The results obtained for mean HCH levels were 0.094 and 0.093 mg/kg on fat basis in cow's milk and butter samples, respectively. The mean DDT levels were 0.159 and 0.049 mg/kg, respectively. In relation to cow's milk, the total HCH levels in Veracruz state were higher but total DDT levels were comparable to those reported in other countries. On the other hand, organochlorine levels detected in national brand butter samples were lower than those found in other countries, where these pesticides are still used in sanitary actions. These results confirmed that dairy products in Mexico presented organochlorine pesticide residues (owing to their use in sanitary actions) indicating a human exposure through these food products.

Levels of organochlorine pesticides in Mexican butter.

Organochlorine pesticide residues were analyzed in 345 samples of butter purchased from Mexican supermarkets in 1994. Three national brands and one foreign brand were analyzed. Most samples contained residues of gama-HCH (91%), HCB (90%), and p,p'-DDE (88%). Residues of alpha-HCH (63%), p,p'-DDT (42%), beta-HCH (38%), o,p'-DDT (17%), heptachlor epoxide (7%), and endosulfane sulfate (3%) were also detected. Mean values of pesticide residues determined were 0.093 mg/kg fat for total HCH and 0.056 mg/kg for total DDT. Mean values of organochlorine pesticide residues in Mexican butter were comparable with those in a foreign brand.

Detection of some organochlorine pesticides in cow's milk.

This monitoring study of 192 samples of cow's milk collected from the central region of Veracruz state was conducted to determine the contamination levels of organochlorine pesticides. The results obtained for mean DDT and HCH levels were 0.057 and 0.098 mg/kg respectively expressed on fat basis and are within FAO tolerances and similar to those found in other tropical countries.