Table Classification of vitamins by relative transfer efficiency from diet to egg

Transfer efficiency

Vitamin

Very High High

Medium

  • 60 - 80%) (40 - 50%)
  • 15 - 25%)

Vitamin A

Riboflavin Pantothenic acid Biotin

Vitamin B12

Vitamin D3 Vitamin E

Vitamin K

Thiamin

Folacin

Adapted from Naber (1993)

v. Yolk mottling - Egg yolk mottling continues to be a problem that appears sporadically in a number of flocks. Although the condition has been known for some time, there appears to be no definite evidence as to its cause or of ways to alleviate it. Diet has been implicated, but there is no real evidence that nutrition is a factor with the majority of mottling problems that appear. However, it is known that certain feed additives such as nicarbazin can cause a mottling condition if they are inadvertently added to a laying diet. Most cases of yolk mottling are reported in the spring of the year and most often 'disappear' during the summer or fall. However,

Table 4.41 Vitamin content of eggs from hens fed regular or enriched levels of vitamins

Vitamin

Units

Regular egg

Enriched egg

DRI1

% DRI

Biotin

Hg/kg

16

18

30

60

Folic acid

Hg/kg

8.7

10

400

3

Niacin

mg/kg

0.04

0.08

16

1

Pantothenate

mg/kg

0.76

0.77

5

15

Vit A

lU/kg

17.7

22.5

270

8

Vit B1

mg/kg

0.048

0.06

1.2

5

Vit B2

mg/kg

0.21

0.25

1.3

19

Vit B6

mg/kg

0.027

0.03

1.3

2

Vit B12

Hg/kg

0.872

3. 37

2.4

140

Vit D3

Hg/kg

0.39

1 1

5

22

Vit E

mg/kg

1.3

3.78

15

25

Vit K

mg/kg

0.12

0.13

0.12

108

1 Daily recommended intake for adult

1 Daily recommended intake for adult

Table 4.42 Yolk mottling as influenced by temperature

Haugh

Yolk color

Severity of

units

index

mottling (%)

Fresh eggs

85.4

11.3

7.1

Eggs held 1 week at 12.5°C

70.8

10.9

45.6

Eggs held 2 weeks at 12.5°C

66.7

10.9

44.0

Eggs held 1 week at room temperature

-

-

47.6

Eggs held 2 days at 31.7°C

-

-

60.0

whether the season of the year or the type of laying house management is a factor has not been proven. Table 4.42 shows the result of a study in which eggs held for various lengths of time and under different environmental conditions, were checked for severity of yolk mottling. It is evident that the majority of mottling appears during storage. Storing, even at ideal temperature for one week, can result in a marked increase in the condition. It has been suggested that the modern strains of birds are more prone to yolk mottling than are traditional strains although research data does not confirm this assertion.

The vitelline membrane surrounding the yolk is much weaker when yolks are mottled. With severe mottling it is very difficult to manually separate the yolk without breaking the membrane. It is not known if the change in vitelline membrane integrity is a cause or effect of mottled yolks. In terms of nutrition, nicarbazin or high gossy-pol cottonseed are most usually implicated.

vi Albumen quality - The main factor influencing albumen quality is storage time. Over time, especially at temperatures > 10°C, there will be a breakdown of thick albumen, and so loss in egg quality.

Over the last few years there has been increasing concern about the quality of the thin rather than thick albumen in fresh eggs. Most measures of albumen quality, such as Haugh unit, only measure characteristics of the thick albumen, and so apparently 'Grade A' eggs can have problems with the thin albumen. In certain birds, we see the area of thin albumen to be as much as 120 sq. cm., compared to 60 - 70 sq. cm. for a 'normal' egg. These spreading albumens are especially problematic in the fast-food industry where eggs are prepared on flat-surface grills. We have tested various levels of protein and amino acids, and fed birds diets of vastly different acid-base balance, and seen no effect on this phenomenon. We have selected birds producing normal vs. spreading albumen and their offspring show similar characteristics. The current thin albumen problem therefore seems to be an inherited characteristic.

Magnesium plays a role in stabilization of thick albumen, and so there have been studies aimed at improving albumen quality by feeding layers high levels of this mineral. In one study, feeding 4 - 8,000 ppm Mg on top of a basal level of 1500 ppm did help maintain thick albumen after egg storage for 20 d at 20°C. In control eggs, there was almost 70% liquification of thick albumen, while in magnesium enriched birds there was only 25% conversion of thick to thin albumen. Unfortunately, high levels of dietary magnesium cause loss in shell quality and so this has to be considered if magnesium salts are used in layer diets.

There have been inconsistent reports of improvement in albumen quality in response to 10 ppm dietary chromium. On the other hand 10 ppm vanadium results in dramatic loss in albumen quality. Such levels of vanadium can be contributed by contaminated sources of phosphates. Interestingly, the negative effect of vanadium is reported to be corrected by use of 10 ppm chromium in the diet.

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Pregnancy Diet Plan

Pregnancy Diet Plan

The first trimester is very important for the mother and the baby. For most women it is common to find out about their pregnancy after they have missed their menstrual cycle. Since, not all women note their menstrual cycle and dates of intercourse, it may cause slight confusion about the exact date of conception. That is why most women find out that they are pregnant only after one month of pregnancy.

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