Calcium, phosphorus in MBM vary

Calcium, phosphorus in MBM vary

*John H. Goihl is president of Agri-Nutrition Services Inc., Shakopee, Minn. To expedite answers to questions concerning this article, please direct inquiries to Feedstuffs, Bottom Line of Nutrition, 5810 W. 78th St., Suite 200, Bloomington, Minn. 55439, or email [email protected]

THE current cost of feed has nutritionists and swine producers evaluating various feed ingredients for their energy and protein content and possible use in swine diets.

In the mid-20th century, meat and bone meal (MBM) was a major protein ingredient in swine diets because it supplied protein and the minerals calcium and phosphorus. The value of the phosphorus in MBM has been reduced with the increased use of phytase and dried distillers grains with solubles in swine diets.

MBM is defined as the rendered product from mammal tissues, including bone, exclusive of any added blood, hair, hooves, horns, hide trimmings, manure, stomach and rumen contents except in such amounts as may occur unavoidably in good processing practices. It shall contain a minimum of 4.0% phosphorus, and the calcium level shall not be more than 2.2 times the actual phosphorus level. A description of the source is applied as to whether the MBM is from pork or beef.

The effective use of MBM as a source of calcium and phosphorus is dependent on an accurate assessment of the digestibility of these minerals when fed to pigs. There is variability in calcium and phosphorus percentages from different MBM sources because of different composition and processing methods.

Swine researchers R.C. Sulabo and H.H. Stein at the University of Illinois conducted an experiment to determine the apparent total tract digestibility (ATTD) of phosphorus and calcium and the standardized total tract digestibility (STTD) of phosphorus in eight different sources of MBM.

Table 1 summarizes the variation among the MBM sources used in this experiment. The values were obtained by chemical analysis.

Sources 2 and 3 did not meet the minimum phosphorus level of 4.0% for MBM and, therefore, are defined as meat meal.

A total of 72 barrows, with an initial bodyweight of approximately 18.0 kg, were divided into two blocks, depending on birth date, and then were randomly allotted to nine dietary treatments of four replicates each within each block. Pigs were placed in metabolism crates that had a feeder and nipple drinker.

A total of nine diets were formulated. Eight contained 8% of one of the MBM sources plus 15% sucrose, 73% corn starch and 3% soybean oil. The ninth was a phosphorus-free diet to measure the basal endogenous phosphorus loss (EPL). It contained 20% sucrose, 49% corn starch, 28% gelatin, soybean oil and solfa-floc.

No inorganic phosphorus or calcium were added to the eight MBM diets. Vitamins and other minerals were added to all diets to meet or exceed current nutrient estimates for pigs at this weight.

Pigs were fed at three times their estimated maintenance energy requirement divided into two equal meals per day. The first five days were considered an adaptation period to the diets. The feces were collected on days 6-11 and frozen immediately after collection for later analysis. The following equations were used to determine ATTD and STTD:

1. ATTD, % = phosphorus or calcium average daily intake (grams) - phosphorus or calcium average daily output(grams) in feces/phosphorus or calcium average daily intake (grams) x 100.

2. STTD, % = phosphorus average daily intake (grams) - phosphorus average daily output (grams) - EPL (mg/kg of dry matter)/phosphorus average daily intake (grams) x 100.

3. Basal EPL = phosphorus average daily output (grams)/phosphorus average daily intake (grams) x 1,000 x 1,000.

 

Results

Table 2 summarizes the ATTD of phosphorus and calcium and STTD of phosphorus for the eight MBM sources.

The researchers provided the following interpretations of these results:

* There were no significant differences in daily feed intake or daily fecal output among pigs fed the different diets containing the different MBM sources.

* There were differences in daily basal EPL among treatments.

* The ATTD and STTD of phosphorus differed among the MBM sources as well as the ATTD of calcium.

* The models developed by the researchers explained 60-73% of the variability in STTD of phosphorus and 73-85% of the variability in ATTD of calcium in the MBM sources.

The researchers indicated that, regardless of the species from which the MBM was produced, the bone particles in dry, defatted MBM contain 64% ash and 31% crude protein, mostly in the form of collagen, whereas soft tissue particles contain 11% ash and 81% crude protein.

The variations in crude protein and ash concentrations in MBM may reflect differences in bone-to-soft tissue ratios. Generally, MBM from cattle contains considerably greater amounts of bone than MBM derived from swine, thus accounting for the differences in ash content in the final product.

The average ATTD of phosphorus in these eight sources of MBM was 65.9%. Previous experiments ranged from 54% to 85%. The average STTD of phosphorus was 68.8%, which is similar to 67.3% for fish meal but less than the 88.4-98.2% range for inorganic phosphates. The STTD of phosphorus is approximately 26.4% in corn and approximately 52.5% in soybean meal, as reported from previous experiments.

Previously reported relative bioavailability values of phosphorus among different sources of MBM are relatively similar to the range of values for the STTD of phosphorus reported in this experiment. The STTD of phosphorus in this experiment decreased with increasing ash concentrations.

Previous research also has shown that phosphorus in bone tissue has a reduced digestibility compared with phosphorus in soft tissue. Animal protein products with a decreasing percentage of bone tissue result in increased phosphorus digestibility. For example, phosphorus digestibility is 68% for bone meal, 80% for MBM and 85% for meat meal.

The ATTD for calcium in these MBM sources was within the reported range of values for calcium carbonate, which is between 60.9% and 70.9%. Recently reported values for ATTD of calcium in corn and soybean meal are 47-49%.

 

The Bottom Line

This experiment demonstrated that the concentrations and digestibility values for phosphorus and calcium vary among different sources of MBM.

There results were connected to the ash concentration in MBM, which indicated relatively higher concentrations of calcium and phosphorus with higher concentrations of ash. However, the higher concentrations of calcium and phosphorus in MBM resulted in reduced digestibility.

The researchers developed prediction equations using the concentrations of total phosphorus in MBM that may be used to estimate phosphorus and calcium digestibility in MBM for growing pigs.

 

Reference

J. Anim. Sci. Vol. 91, No. 3.

 

1. Variation among eight sources of MBM

 

-Source-

Criteria

1

2

3

4

5

6

7

8

Crude protein,%

52.2

51.2

57.2

52.1

51.7

51.2

45.7

54.2

Ether extract, %

14.1

15.2

14.4

12.6

11.7

11.8

11.6

13.4

Ash, %

28.2

24.7

20.6

29.6

27.8

28.6

33.2

25.3

Calcium, %

9.69

7.12

5.09

10.42

8.86

9.63

11.03

8.30

Phosphorus, %

4.72

3.65

2.59

5.05

4.43

4.49

5.26

4.06

Calcium:phosphorus ratio

2.05

1.95

1.97

2.22

2.02

2.14

2.10

2.04

Lysine, %

3.07

3.16

3.21

2.75

2.92

2.65

2.63

3.07

Tryptophan, %

0.36

0.38

0.41

0.34

0.35

0.28

0.28

0.33

Threonine, %

1.68

1.73

1.98

1.63

1.75

1.56

1.44

1.76

 

2. ATTD of phosphorus and calcium and STTD of phosphorus for different sources of MBM

 

-Source-

Criteria

1

2

3

4

5

6

7

8

Feed intake (dry matter), g/day

530

503

483

508

519

527

489

513

Fecal output (dry matter), g/day

13.42

10.20

11.70

14.64

14.38

13.15

10.76

12.88

ATTD of phosphorus, %

61.6

73.5

80.1

70.2

63.8

52.1

58.6

67.1

EPL*, mg/day

56

54

51

54

55

56

52

55

STTD of phosphorus, %

64.0

76.9

84.4

72.6

66.6

54.8

61.0

69.8

ATTD of calcium %

57.2

73.2

81.0

66.3

62.7

53.0

56.0

62.1

*Basal EPL x daily dry matter intake.

 

Volume:85 Issue:25

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