The variation in fatty acid composition between the "bound" and "free" lipid in stored anchovy meal was determined using gas-liquid chromatographic analysis. A model system of fresh anchovy oil on powdered lactalbumin was also studied to determine the changes in extractability and fatty acid composition which occur during oxidation. All of the lipid-protein systems examined were first extracted with hexane. The extracted protein was then extracted with choroform:: methanol (2:1 v/v), and finally digested in HCl and the hydrolysate extracted with diethyl ether. The chloroform : methanol extract and HCl digestion represented oil which was bound to the protein. Each lipid extract was interesterified with methanol to yield the corresponding methyl esters, and these esters were then analyzed by gas-liquid chromatography. Both quantitative and qualitative analysis was carried out using a diethylene glycol succinate packed column in a gas chromatograph equipped with a hydrogen flame detector. The results of these investigations showed that the oil from anchovy meal differed markedly in fatty acid composition from the corresponding fresh oil. Although the types of fatty acids found were identical to those in the fresh oil, there was considerable quantitative variation. These differences were characterized by smaller amounts of polyunsaturated fatty acids in the meal, and correspondingly larger amounts of saturated and monoenoic fatty acids. The greatest change occurred in the acid, 20:5. Anchovy meal contained a "bound" lipid fraction which varied in quantitative fatty acid composition with the readily extractable lipid. The fractions associated with the protein had higher proportions of 22:4, 22:5, and 22:6, with the acid digest fraction considerably lower in the monoenoic fatty acids. The oxidation of anchovy oil and anchovy oil methyl esters on lactalbumin produced a reduction in hexane extractable lipid with a corresponding increase in lipid which was soluble only in chloroform : methanol or after HCl hydrolysis. These changes were more drastic when untreated anchovy oil was used. The oxidation of anchovy oil methyl esters on lactalbumin produced a reduction in the amounts of polyunsaturated fatty acids present in the hexane extract. The other solvent extractions, however, yielded only higher molecular weight compounds which could not be analyzed by GLC. These observations led to the conclusion that the fatty acids formed compounds which interacted before being bound to the protein. / Graduation date: 1966

Call number: LD2668 .T4 1986 S765 / Master of Science / Animal Sciences and Industry

The aim of this study was to maximize good quality grass silage utilization either by supplying a source of rumen undegradable protein or by a reduction of the concentrate in the diet. A randomized incomplete block design was used to evaluate feed intake, milk production and health incidence occurring in fifty-nine Holstein dairy cow (11 primiparous) distributed randomly to receive three different diets between wk 4 and 24 of lactation. The diets were composed of grass silage (predominance of timothy) offered ad libitum supplemented either with a mixture of cereal grains (wheat:barley 50:50) at 100% of recommendations plus soybean meal (Trt 1), or fish meal (Trt 2), or with cereal grains at 75% of recommendations plus fish meal (Trt 3). The grass silage was harvested at an approximate chop length of 8--10 cm, averaged 37.1% DM and was stored in heap silos. / Finally, an economic evaluation of the treatments was done using milk income, feed cost, health cost, and net income. (Abstract shortened by UMI.)

No description available.

A series of experiments were conducted to measure the mode of action by which fishmeal exerts its effect on milk composition of dairy cows. Production Study One measured the effect of increased fishmeal intake on milk production and milk composition in dairy cattle. Milk fat percentage and yield were decreased by increased fishmeal intake. This decrease was not associated with changes in ruminal fermentation patterns. Plasma long-chain n-3 polyunsaturated fatty acids were increased with increased fishmeal intake. Mammary slices from lactating bovine mammary gland were incubated with eicosapentaenoic acid. Changes in ¹⁴C-acetate metabolism were measured. Acetate oxidation and incorporation into milk lipid were not changed by eicosapentaenoic acid. However, tissue from mammary gland of cows milked 6 to 8 h prior to slaughter had 2 fold higher activity than tissue milked 1 h before slaughter. Disappearance of dry matter, crude protein, and lipid in fish meal from undegradable bags in the rumen was measured. Dry matter and crude protein degradation of fish meal were similar to published values. Lipid escaped rapidly with greater than 70% removed by 8 h. A subsequent fish oil infusion study revealed that intraruminal fish oil treatment did not significantly alter ruminal fermentation, or change fatty acid profiles in duodenal digesta, plasma, or milk. Duodenal infusion increased plasma concentrations of n-3 fatty acids but did not affect milk lipid fatty acid composition. A second production study compared the effects of fish meal versus fish oil on milk production and composition, and changes in fatty acids in plasma and milk. Fish meal significantly increased plasma n-3 fatty acids compared to the fish oil treatment. Residual fatty acids contained in fish meal seemed to be protected from rumen degradation and probably remained intact for digestion and absorption since plasma n-3 fatty acid concentrations increased. No changes in milk yield or composition were due to the experimental treatments. Fat in fish meal and fish oil source differed significantly in their ability to alter milk composition and plasma fatty acid profiles. / Ph. D.

Attempts to improve upon the crude protein feeding system have strived to characterize feedstuffs with respect to ruminal protein degradability. In vitro an in situ procedures fall short of this goal by not accounting for ruminal turnover. Six lactating cows, fitted with ruminal and duodenal cannulae, were utilized for in vivo determination of protein degradability by employing a double-marker system. Treatments were corn silage-based diets supplemented with 2:1 soybean meal:fish meal nitrogen (SF) or 1:2 soybean meal:fish meal nitrogen (FS) at levels of 15. 9 and 16.0 percent protein. Ruminal cobalt ethylenediaminetetraacetic acid (CoEDTA) infusions marked liquid phase (LP) digesta and Yb-soaked hay was used as a solid phase (SP) marker. Duodenal digesta was separated into SP and LP at 3000xg. Least squares means of LP flows did not differ for total, precipitable protein, or microbial nitrogen, for SF and FS. Total solid phase flow of dry matter was higher for FS (9.06 kg/d) than for SF (7.97 kg/d), although intakes did not differ. Milk composition and yield did not differ for FS and SF. Average daily gain was 0.12 kg/d for SF and 1:26 kg/d for FS. Whole-tract digestibilties were not different although rumen digestibility of dry matter was 24.9% for FS and 35.7% for SF, and duodenal recovery of N was 93.8% for SF and 107.5% for FS. Inclusion of a higher level of fish meal in the diet increased the proportion of feed proteins delivered to the small intestine, increasing weight gain while having no effect on milk production. / Master of Science