Formulation changes and feed texture

With diets formulated to least cost ingredient input, it is often necessary to change ingredient concentrations, and depending upon economic circumstances, the computer invariably 'asks' for major changes at certain times. In these situations, nutritionists are often reluctant to make major ingredient substitutions in consecutive diets, on the basis that such change may adversely affect feed intake and hence product. In a recent study, birds were fed a range of diets over a 12-month cycle, with the situation of least cost where major changes in ingredient use occurred in most months. Control birds were fed least cost formulated diets, although in this situation major ingredient changes from month to month were not allowed, rather these changes occurred more gradually as occurs commercially. Birds responded reasonably to these changes and no major adverse effects were seen. However, a slight improvement in egg production and egg size with a conventional least cost system, where diet changes were tempered to prevent drastic swings in diet composition, some what negated the savings in feed costs seen with absolute least cost. The economic situation in terms of egg return minus feed cost was in favor of conventional least cost, mainly due to a doubling of the mortality rate with the major swings in diet composition. It seems that while the absolute least cost diets are initially attractive in reducing feed cost, they offer little overall economic advantage and generally pose an additional economic risk.

The texture of diets for laying hens is perhaps subject to more variability than for any other class of poultry. In some countries, very fine mashes are used, whereas crumbles are used in other areas. There is little doubt that any type of feed texture can be made to work physically, although bird response is not always the same. Our research data suggests that regardless of nutrient profile, layers prefer large particles of feed. When layers were offered a crumbled diet, they show a marked preference for the largest size particles available. Smaller particles of feed only start to disappear later within a 24 h period, when all the large particles have been eaten. In this study, there was no disappearance of very fine particles <0.6 mm, although this result may be confounded with the break down of large particles. Feed intake increased when birds were suddenly presented with feed of small particle size, and intake temporarily declined when birds were offered only large size particles. A criticism of mash diets is that they tend to separate out when used in long runs of feed trough, and especially where continous chain feeders are used. From a survey of commercial flocks in Ontario, we found comparable physical separation of feed with both mash and crumbles (Table 4.22).

In this study, feed samples were taken directly from the feed tank and then at points progressively further from the initial point of distribution within the feed trough. Particle and nutrient separation were seen at all farms (Table 4.22). With crumbled feed, particle size was dramatically reduced as feed traveled along the trough, although this was not associated with any major change in nutrient profile. Higher calcium levels per se in the trough, rather than the tank, relates to feed samples in the trough including all feed in front of the bird that included fine particles beneath the feeder chain. Particle separation was also seen with the mash feeds, although this was only during the first 18 m run of the feed trough.

Table 4.22 Particle segregation and calcium analysis of feed collected from farms using either mash or crumbles (%)

Type of feed

Particle size (mm)

At feed tank

Distance along feed trough (m) +18 +36 +72 +108

Crumbles

>2.36

46.0

29.8

25.3

20.6

16.0

>1.18

28.8

26.5

25.5

24.7

23.7

>0.85

6.9

9.4

10.1

10.9

11.1

>0.71

3.4

5.5

6.1

6.7

7.1

>0. 60

3.2

5.6

6.2

6.7

7.1

<0.60

11.7

23.2

26.8

30.3

33.8

%Calcium

3.5

4.3

4.5

4.7

4.5

Mash

>2.36

17.3

10.0

8.3

8.5

10.5

>1.18

22.7

21.1

20.0

19.6

21.0

>0.85

11.9

13.4

13.2

14.5

15.1

>0.71

7.2

8.9

9.0

9.2

9.0

>0.60

7.4

8.6

9.0

9.3

8.2

<0.60

33.5

38.0

40.5

38.9

36.2

%Calcium

4.0

4.9

5.3

5.6

5.0

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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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