Results 2. Performance Directory UMM :Data Elmu:jurnal:L:Livestock Production Science:Vol67.Issue1-2.Dec2000:
A .W. Jongbloed et al. Livestock Production Science 67 2000 113 –122
117
3. Results 3.2. Performance
3.1. Chemical composition Throughout the trial no treatment-related health
problems in pigs were observed. As the animals Contents of proximate nutrients and minerals were
consumed far more feed than anticipated, we reduced very similar among the diets Table 3, except for
the number of pigs per pen in the last block from 6
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the Ca content in the diet with 32 g kg lactic
to 5. In Table 4 is presented the performance of pigs acid1microbial phytase, which was slightly lower
over 5 weeks of this experiment. Average initial and than in the other diets. The average Na, K, Cu and
final BW of the animals were 22 and 47 kg,
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Zn contents were 1.3, 11.6 g kg and 36 and 88 mg
respectively. Animal performance was very good,
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kg DM, respectively. The barley had a phytase
being affected by the treatments. Feed intake of pigs
21
activity of 330 FTU kg , resulting in low phytase
receiving microbial phytase in their diets was higher activities
in the
diets without
supplementary than of those without supplementary phytase P 5
21
Natuphos ranging between 138 and 181 FTU kg
0.04. Growth rate on the feeds with acids was
DM. In the Natuphos supplemented diets phytase
higher, and especially when microbial phytase was
21
activity ranged from 549 to 648 FTU kg DM,
added and also a very favourable feed conversion
21
being about 100 FTU kg lower than assumed.
ratio 2.15 was obtained. Both microbial phytase Phytase activity in the phytase-supplemented diets
and the acids had a positive effect on growth rate and with the highest dose of acid is slightly lower than at
feed conversion ratio P 50.039. However, there the lower dose of the organic acid, being on average
was no significant interaction of phytase and acids on
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40 FTU kg . This is more or less within the
these characteristics. accuracy of determination of phytase activity, being
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50 FTU kg . Acidity of the diets ranged from 5.8
3.3. Apparent total tract digestibility pH-units in the basal diets to 4.7 pH-units in the diet
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with supplementary lactic acid 32 g kg . The
Apparent total tract digestibility of DM, OM, ash, analysed amounts of lactic and formic acids were as
Ca, Mg and P are presented in Table 5. Digestibility planned.
of DM was enhanced by microbial phytase and acid
Table 3
21 21
a
Analysed chemical composition g kg DM; DM and organic acids in g kg
, as-fed Phytase
2 2
2 2
2 1
1 1
1 1
Acid –
LA LA
FA FA
– LA
LA FA
FA
21
Acid dose g kg –
32 16
16 8
– 32
16 16
8 DM
871 862
867 862
869 868
864 863
861 867
Ash 56
56 56
56 56
56 56
57 57
56 OM
944 944
944 944
944 944
944 943
943 944
CP 199
201 206
204 202
195 202
199 201
198 Cfat
52 59
– 60
– 54
60 –
58 –
Cfibre 51
53 –
53 –
52 53
– 54
– Ca
6.24 6.33
6.37 6.64
6.53 6.37
5.74 6.27
6.27 6.61
Mg 2.35
2.31 2.31
2.35 2.36
2.33 2.37
2.32 2.29
2.38 Total P
4.77 4.74
4.72 4.78
4.78 4.80
4.87 4.73
4.73 4.79
BC pH 4 meq kg 506
331 418
342 429
511 291
412 340
420 BC pH 3 meq kg
681 635
665 646
675 697
596 662
644 667
IP-P 2.95
– –
– –
3.02 –
– –
– Phytase act. FTU
181 145
181 138
142 642
549 584
552 594
Lactic acid 100 –
23.0 11.6
– –
– 22.7
12.3 –
– Formic acid 100
– –
– 11.4
5.3 –
– –
11.3 5.2
mmol acid –
256 129
247 115
– 252
137 246
112 pH
5.8 4.8
5.2 4.9
5.3 5.8
4.7 5.2
4.9 5.3
a
BC, buffering capacity; IP-P, P present as inositol P.
118 A
.W. Jongbloed et al. Livestock Production Science 67 2000 113 –122 Table 4
21 21
21 21
21
Feed intake kg animal day
, gain g animal day
and average feed conversion ratio kg feed kg daily gain as affected by
microbial phytase, organic acids and their interaction Phytase
Acid Intake
Gain Feed conversion ratio
a a
a
2 –
l.690 691
2.46
ab b
ab
2 Lactic
1.769 758
2.34
a b
bc
2 Formic
1.736 758
2.29
ab b
bcd
1 –
1.743 772
2.28
ab c
cd
1 Lactic
1.792 836
2.15
b c
d
1 Formic
1.861 874
2.14 RMSE
0.130 32.9
0.118 P values
Phytase 0.040
,0.001 ,0.001
Acids 0.171
,0.001 0.039
Phytase3acid 0.376
0.332 0.941
abcd
Within a column, values with different superscripts are significantly different at P ,0.05; RMSE, root mean square error; ]
Œ
S.E.M.5RMSE n, where n 58 for no acid means and n 56 for acid means.
P 50.015 and ,0.001, respectively, although the expected, microbial phytase exerted a large effect on
effect of microbial phytase was limited. Also, ash the apparent digestibility of total P P ,0.001,
digestibility was enhanced by microbial phytase and which was equal to 16-units or 0.69 g of digestible
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the acids P ,0.001 and both factors interacted P kg
of feed. These acids also had a positive effect meaningfully P 50.046. Digestibility of Ca was
on digestibility of P 4.9-units. Moreover, there affected by both microbial phytase and acids P ,
was a significant interaction between phytase and 0.001. No main effect of microbial phytase on Mg
acids P 50.01. The formic acid in combination digestibility could be found, whereas the organic
with microbial phytase showed a further positive acids tended to enhance its digestibility. Further-
effect equal to almost 5-units. For all digestibilities more, there was a significant interaction between
that were measured, formic acid in combination with phytase and acids on Mg digestibility P 50.042. As
microbial phytase resulted in the highest values.
Table 5 Average apparent total tract digestibility of DM, OM, ash, Ca, Mg and P as affected by microbial phytase, organic acids and their
interaction Phytase
Acid DM
OM Ash
Ca Mg
P
a a
a a
a a
2 –
81.80 83.97
45.58 47.14
22.90 25.00
b bc
b b
ab b
2 Lactic
82.47 84.45
49.18 53.53
25.31 29.87
b cd
b b
a b
2 Formic
82.66 84.66
49.14 54.92
24.38 29.87
a a
b b
b c
1 –
81.97 83.88
50.12 55.81
23.91 41.48
b ab
c c
a d
1 Lactic
82.54 84.25
53.91 59.14
23.55 45.71
c d
d d
b e
1 Formic
83.31 84.91
56.33 62.07
27.03 51.27
RMSE 0.338
0.315 1.281
1.862 2.010
2.171 P values
Phytase 0.015
0.988 ,0.001
,0.001 0.419
,0.001 Acid
,0.001 ,0.001
,0.001 ,0.001
0.068 ,0.001
Phytase3acid 0.113
0.211 0.046
0.217 0.042
0.010
abcd
Within a column, values with different superscripts are significantly different at P ,0.05. RMSE, root mean square error; ]
Œ
S.E.M.5RMSE n, where n 58 for no acid means and n 56 for acid means.
A .W. Jongbloed et al. Livestock Production Science 67 2000 113 –122
119 Table 6
21 21
Average pH, osmolarity mosmol l , Ca, Mg and P content g l
in the urine as affected by microbial phytase, organic acids and their interaction
Phytase Acid
pH Osm.
Ca Mg
P
ab ab
2 –
8.01 535
1.12 0.23
0.0073
a ab
2 Lactic
7.96 659
1.42 0.26
0.0069
b a
2 Formic
7.95 572
1.03 0.21
0.0058
c b
1 –
7.81 577
0.54 0.20
0.0166
c ab
1 Lactic
7.87 655
0.38 0.23
0.0142
c ab
1 Formic
7.88 622
0.44 0.23
0.0109 RMSE
0.17 109
0.321 0.045
0.0100 P values
Phytase 0.105
0.472 ,0.001
0.545 0.018
Acids 0.999
0.152 0.452
0.452 0.654
Phytase3acids 0.755
0.810 0.173
0.173 0.851
abcd
Within a column, values with different superscripts are significantly different at P ,0.05. RMSE, root mean square error; ]
Œ
S.E.M.5RMSE n, where n 58 for no acid means and n 56 for acid means.
formance of the pigs is therefore predominantly due 3.4. Characteristics of urine
to the higher feed intake, although also positive effects have been noted by microbial phytase even
The urinary pH, osmolarity and Mg content were when the pigs are fed above their P requirement
similar, irrespective
of supplementary
acid or
Jongbloed et al., 1996. phytase doses Table 6. No effect of these organic
Also, the supplementary organic acids had a acids on urinary pH was expected because these
positive effect on performance of the pigs in the diets acids are known to be metabolised in the liver for
with and without microbial phytase. This enhanced various metabolic processes. The concentration of Ca
response is reported in numerous publications as in the urine was reduced by microbial phytase P ,
reviewed by Partanen and Mroz 1999, although the 0.001 because the deficit of digestible P in the
effect in our experiment is confounded with a higher metabolic pool was much lower Jongbloed, 1987;
supply of digestible P on average 0.2 g kg. Also, Mroz et al., 1993. Microbial phytase increased
Radcliffe et al. 1998 reported a better performance significantly the P concentration in the urine. How-
of pigs fed diets with 1.5 to 3.0 citric acid at ever, concentrations are very low, which means that
digestible P levels below requirement. It is generally the animals on all treatments were still fed below
assumed that the response of pigs to organic acids their P requirement.
declines with increasing age of the animal and development of gastric secretion Kirchgessner and
Roth, 1980, 1982; Easter, 1988, but for the category