Comparative Research Data on Rats
Comparing TestDiet® 5755 purified ingredient Basal Diet

to LabDiet® 5008 grain-based Rat Feed

Rat Research

Similar growth and reproduction studies were conducted in Sprague-Dawley rats as were done with the ICR mice. Three generations of animals were used in the study. The performance comparison is made against the natural grain-based LabDiet® 5008 which is known for its excellent value in the production of rats. Each generation test consisted of 10 male and 10 female weanling animals from the colony maintained at the Purina Mills Animal Research Center. The experimental animals were randomly assigned to the treatments. The diets were provided in meal form during the 28-day test period. The rats from the growth studies were maintained on the respective diet until breeding age at approximately 90 days of age and served as breeder pairs in this study. Each breeder pair was maintained in production for a maximum of four months. Consequently, if 10 breeding females were used in each phase of the study, many of the fourth litters were not recorded during the time provided.

Rat Growth Studies

TestDiet®
5755

"Basal Diet"

 

LabDiet®
5008

 

(Purified)

 

(Grain-Based)


Average gains (gms)

M

F

 

M

F

 

F1 generation

157

110

 

162

115

 

F2 generation

155

108

 

172

114

 

F3 generation

155

105

 

166

109

Average F1 - F3

156

108

 

167

113

Grams feed/grams gain

 

F1 generation

2.5

3.4

 

2.6

3.4

 

F2 generation

2.4

3.1

 

2.5

3.3

 

F3 generation

2.8

4.4

 

2.5

3.7

Average F1 - F3

2.6

3.6

 

2.5

3.5


Rat Breeding Studies

TestDiet®
5755

"Basal Diet"

 

LabDiet®
5008

Number of females started

30

 

29

Number of litters produced

116

 

107

Number of litters weaned

109

 

99

Average number born alive

10.5

 

10.8

Average number weaned

9.2

 

9.0

Average 20-day weights (gms)

M

F

 

M

F

 

F1 generation

43.2

42.7

 

38.2

37.2

 

F2 generation

51.6

48.0

 

44.7

42.4

 

F3 generation

41.6

41.6

 

36.4

37.8

Average F1 - F3

45.5

44.1

 

39.8

39.1

Number of rats weaned:
3 generations

1003

 

891

 

 

 

 

Actual litters weaned x 100
Maximum litters possible

90.8

 

85.3


Conclusions

The reproductive performance of the breeder rats maintained for three generations on the TestDiet® 5755 ("Basal Diet") was excellent. The growth rate from birth to 20 days (weaning) on 5755 was outstanding for each generation of young. The females did an excellent job of suckling the young and the young began to eat the diet at an early age. Through the three generations no evidence of nutrient depletion occurred in any of the animals.

8/14/98

 

See also:

Comparative Research Data on Mice

Purified Diets