The effects of conjugated linoleic acid (CLA) and canola oil on the fatty acid composition and quality of eggs from laying hens

Dietary conjugated linoleic acid (CLA) causes adverse effects on quality of eggs by modifying the fatty acid composition of the yolk. Supplementing oils prevent CLA-induced changes, but cause a decrease in the level of egg CLA. The objective of the study was to investigate the incorporation of CLA into the egg and its effect on the fatty acid metabolism when laying hens were fed diets containing different levels of canola oil. Hens (15 per group) were assigned to six groups and were fed for 50 days diets containing 0.5% canola oil (Group A), 0.5% CLA (Group B), 0.5% CLA plus 1.25% canola oil (Group C), 0.5% CLA plus 2.5% canola oil (Group D), 0.5% CLA plus 5% canola oil (Group E) or 0.5% CLA plus 10% canola oil. Eggs were collected daily. Three eggs per group were used for fatty acid analysis. Eggs laid on days 1 to11 were stored at 4 °C or room temperature for 30 days, and were separated into yolk and albumen for pH analyses. Yolk from Group B had increased concentrations of C16:0 and C18:0 and decreased concentrations of C18:1(n-9) compared to Group A. Adding 5% or 10% canola oil (Groups E or F) to the diet prevented an increase in C16:0 and C18:0 and a decrease in C18:1(n-9) concentrations. Relative amounts of CLA in eggs from Groups A, B, C, D, E and F were 0, 2.38, 2.33, 1.68, 1.36, and 1.17%, respectively. The concentrations of C18:3(n-3) in Groups A, B, C, D, E and F were 0.23, 0.25, 0.61, 0.70, 1.23 and 1.58%, respectively. The ratios of UFA/SFA in the eggs from Groups B, C and D decreased. When the eggs were stored at 4 °C, the yolk from Groups B, C and D had higher pH values than the other treatments, while the albumen pH of eggs from Groups B, C and D were lower. However, when eggs were stored at room temperature, no abnormal pH changes were observed in the yolk or albumen. This study suggested that adding a certain level of canola oil rich in n-3 fatty acids restored the level of egg yolk SFA to UFA, prevented CLA-induced abnormal changes in egg quality and thus led to a higher level of C18:3(n-3) and CLA in the egg. Keywords: Conjugated linoleic acid; unsaturated fatty acids; egg yolk and albumen pH; chickens South African Journal of Animal Sciences Vol. 35 (3) 2005: pp.172-17

Effect of dietary oils and conjugated linoleic acid on the growth performance of broilers vaccinated with the La Sota Newcastle vaccine

The objective of this study was to investigate the effects of dietary oils on growth performance of broiler chicks vaccinated with La Sota vaccine against Newcastle disease. One hundred and seventy five 1-week old Ross PM3 male broiler chicks were randomly allocated to five dietary groups (n = 35 chicks/group) and fed diets supplemented with 0.5% sunflower oil (Group A), 0.5% olive oil (Group B), 0.5% beef tallow (Group C), 0.5% conjugated linoleic acid (CLA, Group D) or 0.5% hazelnut oil (Group E) for five weeks. Diets contained 230 g crude protein/kg and 12.97 MJ metabolisable energy (ME)/kg (starter diet); 220 g crude protein/kg and 12.97 MJ ME/kg (grower diet) or 200 crude protein/kg and 12.97 MJ ME/kg (finisher diet). The broiler chicks were vaccinated with La Sota Newcastle vaccine at 22 days of age. Body weights were measured weekly and carcass characteristics and some organ (liver, heart, gizzard and intestine) weights were determined after slaughter. The growth rates of broilers from the Groups A, C and E were negatively influenced by vaccination, compared to Group D, which maintained its growth rate. There was no difference in the proportions of abdominal fat (%) of the chickens among the groups. The respective relative organ weights did not differ significantly between the respective dietary treatments. This study showed that the broiler chicks fed a diet supplemented with CLA had significantly better performance and carcass weights compared to the other groups. The present study also indicated that CLA included at a level of 0.5% in the diet prevented weight loss due to vaccination. South African Journal of Animal Science Vol. 37 (2) 2007: pp. 74-8

Effect of storage temperature on the quality of eggs from conjugated linoleic acid-fed laying hens

This study was designed to investigate the effects of storage temperature on the quality of eggs from conjugated linoleic acid (CLA)-fed laying hens. For 40 days laying hens (20 per group) were fed a diet containing either 0.5% maize oil (Group A, Control) or 0.5% CLA (Group B). For fatty acid analysis, three eggs were collected after the eighth day of feeding. After two days of feeding, eggs were collected and stored for 28 days at 4°C, 15°C or 24°C for colour quality assessment. For pH measurements, 30 eggs from each group were stored at 4 C or room temperature (21-24°C) for one, two or three weeks. Dietary CLA caused higher levels of C16:0 and C18:0 and lower levels of C16:1(n-7) and C18:1(n-9) compared to the control group. Egg yolk from Group B had higher levels of c-9, t-11 and t-10, c-12 CLA than the control group. The ratio of total saturated to unsaturated fatty acids (SFA/UFA) increased 2.4-fold in the eggs from CLA-fed hens. CLA eggs stored at 4°C had higher pH values in yolk and lower pH values in albumen compared to those from the control group. However, pH values of yolk or albumen in eggs stored at 21-24°C were similar in the control and treatment groups. Dietary CLA caused significant colour changes in yolk and albumen of the eggs stored at 4°C and 15°C. No colour changes were observed in the yolk and albumen of CLA eggs at 21-24°C. Results indicated that dietary CLA influenced fatty acid composition of eggs and had negative effects on the quality of eggs stored at 4°C or 15°C, but not at room temperature (21-24°C). It is suggested that CLA probably changed the permeability of the vitelline membrane during cold storage. South African Journal of Animal Science Vol. 36(1) 2006: 13-1

BEEF PRODUCER CHOICE IN CATTLE MARKETING

In addition to the conventional auction method of cattle marketing, alternative marketing arrangements include sale by private treaty, video auction, retained ownership, and use of strategic alliances. This study examines use of alternative marketing arrangements and types of producers using each. Thirty-nine percent of producers used alternative arrangements.Marketing,

Beef Producer Choice in Cattle Marketing

In addition to the conventional auction method of cattle marketing, some alternative marketing arrangements include sale by private treaty, video auction, retained ownership, and use of strategic alliances. This study finds that 91% of Louisiana producers use conventional auctions, while 39% use other types of marketing arrangements. The most heavily used alternative marketing arrangement is private treaty, at 26%. Those producers using alternative marketing arrangements tend to be larger, have heavier weaning weights, have more diverse farming operations, be younger, have greater contact with their county extension agents, and depend less on income from off-farm sources.cattle marketing, conventional auction, private treaty, strategic alliance, video auction, Livestock Production/Industries, Marketing,

Role of Alpha Oscillations During Short Time Memory Task Investigated by Graph Based Partitioning

In this study, we investigate the clustering pattern of alpha band (8 Hz - 12 Hz) electroencephalogram (EEG) oscillations obtained from healthy individuals during a short time memory task with 3 different memory loads. The retention period during which subjects were asked to memorize a pattern in a square matrix is analyzed with a graph theoretical approach. The functional coupling among EEG electrodes are quantified via mutual information in the time-frequency plane. A spectral clustering algorithm followed by bootstrapping is used to parcellate memory related circuits and for identifying significant clusters in the brain. The main outcome of the study is that the size of the significant clusters formed by alpha oscillations decreases as the memory load increases. This finding corroborates the active inhibition hypothesis about alpha oscillations

Simulation of associative learning with the replaced elements model

Associative learning theories can be categorised according to whether they treat the representation of stimulus compounds in an elemental or configural manner. Since it is clear that a simple elemental approach to stimulus representation is inadequate there have been several attempts to produce more elaborate elemental models. One recent approach, the Replaced Elements Model (Wagner, 2003), reproduces many results that have until recently been uniquely predicted by Pearce’s Configural Theory (Pearce, 1994). Although it is possible to simulate the Replaced Elements Model using “standard” simulation programs the generation of the correct stimulus representation is complex. The current paper describes a method for simulation of the Replaced Elements Model and presents the results of two example simulations that show differential predictions of Replaced Elements and Pearce’s Configural Theor