- Email: [email protected]
Feed intake, milk yield and milk composition by replacing unprotected fat by Ca-soaps for dairy cows
Animal Feed Science and Technology, 22 (1989) 193-202
193
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
Feed Intake, Milk Yield and Milk Composition by Replacing Unprotected Fat by Ca-soaps for Dairy Cows JOHN E. HERMANSEN
National Institute of Animal Science, P.O. Box 39, 8830 Tjele (Denmark) (Received 13 February 1987; accepted for publication 23 December 1987)
ABSTRACT Hermansen, J.E., 1989. Feed intake, milk yield and milk composition by replacing unprotected fat by Ca-soaps for dairy cows. Anim. Feed Sci. Technol., 22: 193-202. The effect of substituting traditional animal fat with saponified animal fat was investigated in experiments in 2 commercial herds: (1) a Danish Black and White herd ( 18 cows in mid-lactation per treatment) given a complete ration ad libitum; (2) a Jersey herd (15 cows in mid-lactation per treatment) given fixed amounts of concentrates containingthe fat and given silage ad libitum. In both experiments, the daily allowance of saponified animal fat was lower than the corresponding level of traditional animal fat because of a lower fat content in the saponified product than expected. The degree of saponification was estimated at ~ 70%. In Experiment 1, where the level of experimental fat amounted to 759 and 882 g, respectively, per cow daily, feed intake and milk yield tended to increase and the yield of butter fat was increased significantly (100 g per cow daily ) when using saponified animal fat. Furthermore, the content of linoleic acid in the milk was increased. In Experiment 2, the level of experimental fat was ~ 500 and 600 g, respectively, per cow daily, while the basic ration contained ~ 300 g. No significant effect on yield of milk and butter fat or the content of linoleic acid in the milk was found. It is concluded that the use of saponified animal fat is a means by which the positive effect on milk production of supplementing fat can be prolonged to higher levels of fat in the ration than can be reached with traditional animal fat.
INTRODUCTION
Several reports, summarized by Palmquist (1984a), have shown that the negative effect on rumen fermentation which is seen by feeding unprotected fat is avoided when the fat is given in the form of pre-formed Ca-soaps, which are rather insoluble in the rumen at a normal pH. Similar results have been found with the Na-salt of palm acid oil (Moller, 1986). On the other hand, only a few and small-scale results concerning the effect 0377-8401/89/$03.50
© 1989 Elsevier Science Publishers B.V.
194
on milk yield are available and do not show a consistent effect (Palmquist, 1984b; Chalupa et al., 1985). The aim of the present work was, therefore, to estimate the effect on feed intake and milk yield of replacing traditionally used animal fat (tallow or lard rendering) with the same type of fat given as Casalts. MATERIALSAND METHODS Two experiments in which traditional animal fat was replaced by Ca-soaps of the same type of fat were carried out in 2 commercial herds (tie-stalls) of the breeds Danish Black and White (SDM) and Danish Jersey, respectively. The saponified animal fat was supplied by N.L. Mathiesen, N~erum, Denmark, and the concentrates mixture containing either saponified or traditional animal fat was supplied by A. Toft A/S, Durup, Denmark. Management and feeding were carried out by the herdsmen while the registrations were made by a technician.
Experiment I Thirty-six SDM cows of an average body weight of 520 kg and in Weeks 324 of lactation were paired according to number of lactation, stage of lactation and actual yield of 4% fat-corrected milk, and randomly allotted to 2 treatments. Sixteen of the cows were in their first lactation. For a period of 10 weeks, the 2 groups of cows were given a complete ration ad libitum containing a concentrates mixture with either traditional animal fat or saponified animal fat. On a dry matter basis, the complete ration consisted of 23.4% concentrates (experimental feed), 10.6% chopped NH3-treated straw, 27.4% fodder beets, 21.1% grass silage, 15.1% whole crop barley silage, 0.8% urea and 1.6% minerals. The concentrates mixture consisted of the following ingredients: 50% soyabean meal; 15% barley; 5% cane molasses; 3% albumin; 3% lignosulphonate; 2% minerals; either 22% saponified tallow/lard rendering or 19% tallow/ lard+ 3% CaC03. The concentrates were treated with 0.3% formaldehyde. The complete ration was calculated to contain per kg dry matter (DM) ;0.94 Scandinavian Feed Units (SFU), 170 g crude protein and 7 g of Ca. Daily milk yield and feed intake were determined individually over 1 day and night, 5 and 8 times, respectively, through the experimental period. In relation to milk recording, a common milk sample from each group of cows was produced for determining iodine value and, the last 2 times, fatty acid composition of the milk. Gain was determined by weighing the cows on 2 successive days at the beginning and end of the experiment.
195
Experiment 2 Forty-five Jersey cows in Weeks 6-21 of lactation and with an average body weight of 368 kg were selected. The cows were blocked in groups of 3 and randomly allocated within each block to one of the following 3 treatments (types of concentrates): traditional animal fat, a palmitic and stearic acid-rich type of fat, and for the third group saponified animal fat. For a period of 9 weeks, the cows were given the concentrate mixtures consisting of 50% cotton seed meal, 15% soya-bean meal, 5% molasses, 5% meat bone meal, 3% albumin, 3% lignosulphonate, 2% minerals and 15% traditional animal f a t + 2% CaCO3 or 15% palmitic/stearic fat-mixture+2% CaCO~ or 17% Ca-saponified animal fat, respectively. The concentrate mixtures were treated with 0.3% formaldehyde. The concentrates were given in fixed and equal amounts to all the cows (3.7 kg DM per cow daily). In addition, the cows were given fodder beets (5.6 kg DM) and brewers grain (2.4 kg DM) in fixed amounts, and silage and hay ad libitum - - the simplified feeding system (Ostergaard, 1979). Milk yield, milk composition and gain were recorded in the same way as in Experiment 1. Feed intake (excluding intake of experimental feed) was recorded for the herd (110 cows) as a whole.
Analytical procedures The feed was analysed according to conventional methods described by Jakobsen and Weidner (1973). Fatty acid composition in feed and milk was determined by gas chromatography, including an internal standard of C15:0 and C 17:0. Buffer solubility and nylon bag degradability of the concentrate protein was determined as described by Madsen and Hvelplund (1985).
Statistical procedures The effect of treatment on yield, gain and, in the SDM herd, feed intake on average for the experimental period was analysed for the 2 herds using the following model: Y= average + bl" (no. of days in lactation at start) + b2" (yields in 4% fat-corrected milk at start) + source of fat + residual for the individual cow Fatty acid composition and iodine value of the milk were evaluated by a t-test of the differences between treatments on the day of collection.
196 RESULTS
Experiment I The chemical composition of the concentrates is given in Table 1. The fat content of the concentrates containing saponified animal fat was lower than planned, probably because the fat content in the Ca-saponified product was lower than expected when the composition of the concentrate mixture was planned. The resulting difference in fatty acid content, expressed as the sum of the measured fatty acids given in Table 1, was not negligible. The degree of saponification was evaluated as the difference between the ether extract part and the Stoldt fat part. The ether extract amounted to 5.4% of DM, which would give a saponification of ~ 72%. Feed intake, yield and gain are given in Table 2. It appears from Table 2 that feed intake tended to increase when using saponified fat. The total fat intake was, however, lowest in that group because of the lower fat content in the concentrates. The cows given saponified fat yielded 100 g butterfat more per TABLE1 Chemical composition of the concentrates, Experiment 1 Saponified animal fat
Traditional animal fat
Dry matter (%)
88.0
87.4
Composition of DM Crude protein (%) Stoldt fat (%)2 Crude fibre (%) Ca (%)
29.7 19.3 5.1 1.9
29.2 23.7 5.2 1.5
Identified fatty acids (distribution) (%)1 C12:0 C14:0 C14:1 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3
Sum ~Weight % of methyl esters; 0 =trace. 2Ether extract after hydrolysis with HCI.
0.0 0.4 0.1 4.0 0.5 2.5 4.8 0.9 0.3
13.5
(0) (3) (1) (30) (4) (18) (36) (6) (2)
0.1 0.3 0.1 4.3 0.5 2.8 7.5 2.1 0.3
18.0
(i) (2) (o) (24) (3) (16) (41) (11) (2)
197 TABLE 2 Feed intake, yield and gain per cow daily by the use of saponified animal fat or traditional animal fat, Experiment 1 Saponified fat Feed intake Total DM (kg) Total SFU 1 Stoldt fat in concentrates (g) Yield Milk (kg) Fat (g) Fat (%) Protein (g) Protein (%) 4% fat corrected (kg) Gain (g)
Traditional fat
Difference S- T
P value
0.9 0.6 - 123
(0.11)
16.8 15.5 759
15.9 14.9 882
24.5 1003 4.09 757 3.08 24.8
23.2 903 3.89 708 3.05 22.8
1.3 100 0.20 49 0.03 2.0
(0.13) ( <0.01 ) (0.05) ( < 0.01 )
124
107
(0.10)
231
-
1Scandinavian feed unit.
TABLE 3 Composition of milk fat using saponified animal fat or traditional animal fat, distribution of major fatty acids Saponified fat
Traditional fat
Difference S- T
Weight % of methyl esters C12:0 C14:0 C14:1 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3
2.4 10.4 1.5 34.1 3.2 10.7 33.1 3.9 1.0
2.4 10.5 1.7 34.5 3.1 11.5 33.0 2.4 0.9
0.0 --0.1 --0.2 -0.4 0.1 -0.8 0.1 1.5" 0.1
Iodine value
35.3
33.5
1.8
*P < 0.05.
198 day because o f a higher milk yield as well as a higher fat c o n t e n t o f t h e milk. T h e r e was also a t e n d e n c y t o w a r d s i n c r e a s e d gain with the use of saponified fat. T h e c o m p o s i t i o n of milk fat c o n t a i n i n g > 10 c a r b o n s is given in T a b l e 3, f r o m w h i c h it can be seen t h a t o n l y small differences in milk f a t t y acid comp o s i t i o n were observed, b u t t h e c o n t e n t o f linoleic acid was actually raised by t h e use of saponified fat.
Experiment 2 T h e chemical c o m p o s i t i o n s of t h e c o n c e n t r a t e m i x t u r e s are given in T a b l e 4. As in E x p e r i m e n t 1, t h e fat c o n t e n t of t h e soap c o n c e n t r a t e was less t h a n p l a n n e d , p r o b a b l y for t h e same reason. T h e e t h e r e x t r a c t p a r t of t h e c o n c e n t r a t e s c o n t a i n i n g saponified fat acTABLE 4 Chemical composition of the concentrates, Experiment 2 Saponified animal fat
Traditional animal fat
Saturated fat
Dry matter (%)
88.9
89.6
88.5
Composition of DM Crude protein (%) Crude fibre (%) Stoldt fat (%) Ca (%)
32.3 11.1 15.8 2.0
33.7 11.6 19.0 1.7
31.7 11.0 18.9 1.7
Identified fatty acids (distribution) (%) C12:0 0.0 ( 0 ) C14:0 0.3 ( 3 ) C14:1 0.0 (O) C16:0 2.9 (25) C16:1 0.5 ( 5 ) C18:0 2.0 (18) C18:1 4.4 (38) C18:2 1.2 (10) C18:3 0.2 ( 1 )
0.0 ( 0 ) 0.2 ( 2 ) 0.0 (O) 3.3 (24) 0.4 ( 3 ) 2.2 (15) 5.9 (42) 1.8 (13) 0.2 ( 1 )
O.0 ( 0 ) 0.3 ( 2 ) 0.0 (O) 4.2 (26) 0.1 ( 1 ) 9.0 (56) 1.2 ( 7 ) 0.9 ( 6 ) 0.4 ( 2 )
Sum
11.5
14.0
16.1
Nylon bag degradability of protein (8%)
27
29
33
~Weight % of methyl esters; 0 = trace.
199 TABLE 5 Milk yield and gain given traditional animal fat, saponified animal fat or saturated fat in the concentrates, per cow daily Saponified animal fat Milk (kg) Fat (g) Fat (%) Protein (g) Protein (%) 4% fat corrected (kg) Gain (g)
Traditional animal fat
Saturated fat
P value for effect
18.1
18.5
17.3
0.33
1111 6.16
1115 6.03
1103 6.38
0.94 -
670 3.73
681 3.68
657 3.79
0.58 -
23.9
24.1
23.5
0.68
336
265
260
0.44
TABLE 6 Composition of milk fat at different fat sources in concentrates, distribution of major fatty acids, Experiment 2 Saponified animal fat
Traditional animal fat
Saturated fat
Weight % of methyl esters C12:0 C14:0 C14:1 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3
4.4 12.3 1.2 37.4 2.4 12.4 22.7 4.3 0.9
4.4 12.0 1.2 37.3 2.4 13.6 23.6 4.2 1.0
4.7 12.5 1.1 37.7 2.1 14.4 20.7 3.8 0.7
Iodine value
31.1
30.4
27.8
c o u n t e d for 5.4%. E s t i m a t e d o n t h e basis of the difference b e t w e e n t h e e t h e r e x t r a c t p a r t a n d the S t o l d t fat, t h e s a p o n i f i c a t i o n c a n be e s t i m a t e d at ~ 65%. T h e c o n t e n t of identified f a t t y acids was h i g h e s t in t h e m i x t u r e with satur a t e d fat, b u t it is n o t clear w h e t h e r this result reflects a n a c t u a l l y h i g h e r f a t t y acid c o n t e n t in t h e mixture, as t h e S t o l d t fat c o n t e n t was t h e s a m e as in the m i x t u r e c o n t a i n i n g t r a d i t i o n a l a n i m a l fat. O t h e r i n v e s t i g a t i o n s have revealed
200 that typical, Danish tallow/lard rendering may contain up to 4% of fatty acids with > 18 carbons. As mentioned earlier, the silage intake for the respective groups of cows was not recorded. The average silage intake was estimated at 3.3 kg DM per cow daily and as a consequence, their total intake can be estimated at 15 kg DM, 15 SFU and 830 g fatty acids for the treatment with traditional animal fat, and 527 g fatty acids from the experimental feed. Milk yield and gain are given in Table 5. No significant effect of type of fat was found. The milk composition is given in Table 6. No major differences were found in the saponified fat compared to traditional animal fat. Compared to traditional animal fat, the saturated mixture tended to increase the proportion of C12:0, C14:0, C16:0 and C18:0 at the expense of C18:1 and C18:2, resulting in a markedly reduced iodine value in the butterfat. DISCUSSION The response of the saturated fat (C16:0 and C18:0) in Experiment 2 was very much like the response found in earlier experiments (Hermansen, 1989), i.e. a negative influence on milk yield, but a markedly increased fat content of the milk at this level of inclusion. The experiments did not succeed in showing a consistent effect on milk yield of Ca-soaps compared to traditionally used animal fat. The fact that the Casoap concentrates had a lower fat content than the traditional animal fat and the planned level may have affected the interpretation of the experiments. In Experiment 1, the total intake of animal fat was 880 g per cow. In addition to the fatty acids in the basic ration ( ~ 120 g), the total level of fat (64 g kg -1 DM) is so high that a negative influence on milk fat yield is expected (Ostergaard et al., 1981; Hermansen, 1989). In this case, the use of saponified animal fat has stimulated the milk fat percentage and the milk fat yield. Furthermore, the milk protein yield was stimulated, but this effect must be related to the lower fat allowance with saponified fat, which has resulted in a higher intake of nutrients available for the milk protein synthesis, and it is not reasonable to relate this observation to the type of fat. In Experiment 2, where no significant effect was observed although the fat content of the milk tended to increase with the use of saponified fat, the total fat allowance was also high ( ~ 900 g per cow) because of the use of brewers' grain in the basic ration. The fat in question was, however, considerably lower than in Experiment 1. A total of 85% of the concentrate fat was a result of the experimental manipulation. This amounted to ~ 600 g of animal fat per cow against 820 g in Experiment 1. Because of the use of beet-top silage in Experiment 2, the daily allowance of Ca can be estimated at 1.0% of total DM, which is considerably above Danish standards and the level used in Experiment 1
201 Z (0.7% of DM, corresponding to Danish standards). Even if it is shown that the addition of Ca to the ration cannot fully reverse the negative effect of fat on fermentation (El-Hag and Miller, 1972) and that preformed Ca-soaps are superior to conventional f a t + a d d e d Ca (Palmquist et al., 1985), it has also been shown that the addition of Ca to a ration rich in fat does have a positive influence on rumen fermentation (Jenkins and Palmquist, 1980, 1982; Palmquist and Conrad, 1980; Palmquist and Jenkins, 1980). Therefore, Palmquist (1982) recommends a level of ~ 1.0% Ca in the total DM ration when rich in fat to secure the natural soap formation in the rumen. This means that the difference in response in Trials 1 and 2 may be caused by the smaller amount of fat used in Experiment 2 and/or that the diet conditions in Experiment 2 were relatively in favour of the traditional animal fat. The method of recording milk composition and the lack of determination of the short-chain fatty acids made it impossible to discuss the quantitative transfer of fatty acids to milk. However, in Experiment 1 the proportion of linoleic acid in the milk increased significantly (from 5% of the C18 fatty acids to 8% ) despite a markedly lower allowance of C18:2 and a lower relative proportion of C18:2 of the C18 fatty acids in the concentrates. In Experiment 2 this effect was not seen, probably because of the smaller amount of experimental fat in question and the fact that the C18:2 content of the milk in general was high as a result of the use of brewers' grain. CONCLUSIONS
The present results show that at a high level of fat inclusion in the diet, where a negative effect of traditional animal fat is expected, the use of saponified animal fat will increase milk and butterfat yield markedly. On the other hand, at a moderate level of fat inclusion no such positive effect can be expected. Therefore, it seems reasonable to consider saponified fat as a means by which the positive effect of traditional animal fat on milk production at moderate levels can be prolonged to higher levels of fat in the ration. The results obtained do not allow a direct conclusion on the effect of an increased allowance of saponified fat. However, based on the similarity in response in the present Experiment 1 and the results of Hermansen (1989) concerning increasing allowance of saturated fat, it seems reasonable to suggest a response of ~ 100 g of butterfat per cow daily when increasing the daily allowance of total fat from 45 to 75 g k g - 1 DM by the use of saponified fat.
REFERENCES Chalupa, W., Vecchiarelli,B., Sklan, D. and Kronfeld, D.S., 1985. Responses of tureen microorganism and lactating cows to calcium salts of long chain fatty acids. In: Abstracts for the
202 Eightieth Annual Meeting of the American Dairy Science Association, June 1985. J. Dairy Sci., 68: 110. El-Hag, G.A. and Miller, T.B., 1972. Evaluation of whisky distillery by-products. VI. The reduction in digestibility of malt distillers grains by fatty acids and the interaction with calcium and other reversal agents. J. Sci. Food Agric., 23: 247-258. Hermansen, J.E., 1989. Feed intake and milk yield at increasing supplement of a palmitic and stearic acid-rich type of fat in comparison with animal fat. Anita. Feed Sci. Technol., 22: 179191. Jakobsen, P.E. and Weidner, K., 1973. Chemistry of feedstuffs and animals. Veterinary Faculty for FAO Fellows, Royal Veterinary and Agricultural University, Copenhagen, 69 pp. Jenkins, T.C. and Palmquist, D.L., 1980. Effect of added fat and calcium on rumen lipid metabolism of Holstein cows. J. Dairy Sci., 63 (Suppl. 1 ): p. 153. Jenkins, T.C. and Palmquist, D.L., 1982. Effect of added fat and calcium on in vitro formation of insoluble fatty acid soaps and cell wall digestibility. J. Anim. Sci., 55: 957-963. Madsen, J. and Hvelplund, T., 1985. Protein degradation in the rumen. A comparison between in vivo, nylon bag, in vitro and buffer measurements. Acta Agric. Scand., Suppl. 25: 103-123. Moller, P.D., 1986. Undersogelser over oms~etning af Ca-sseber og frie fedtsyrer i mave-tarmkanalen hos kv~eg. Natl. Inst. Anita. Sci., Copenhagen, Short Communication No. 628, 4 pp. Ostergaard, V., 1979. Strategies for concentrate feeding to attain optimum feeding level in high yielding dairy cows. Natl. Inst. Anim. Sci., Copenhagen, Rep. 482, 138 pp. Ostergaard, V., Danf~er, A., Daugaard, J., Hindhede, J. and Thysen, I., 1981. The effect of dietary lipids on milk production in dairy cows. Natl. Inst. Anita. Sci., Copenhagen, Rep. 508, 140 pp. Palmquist, D.L., 1982. Fat in dairy rations. Feed Int., pp. 46-49. Palmquist, D.L., 1984a. Use of fats in diets for lactating dairy cows. In: J. Wiseman (Editor), Fats in Animal Nutrition. Butterworths. Palmquist, D.L., 1984b. Calcium soaps of fatty acids with varying unsaturation of fat supplements for lactating cows. Can. J. Anim. Sci., 64 (Suppl.): 240-241. Palmquist, D.L. and Conrad, H.R., 1980. High fat rations for dairy cows. Tallow and hydrolized blended fat at two intakes. J. Dairy Sci., 63: 391-395. Palmquist, D.L. and Jenkins, T.C., 1980. Fat in lactation rations: review. J. Dairy Sci., 63: 1-14. Palmquist, D.L., Joyner, A.E. and Jenkins, T.C., 1985. Effect of dietary calcium source on rate of insoluble soap formation in the rumen and digestibility of fiber in sacco. J. Dairy Sci., 68 (Suppl. 1 ): 111.
193
Elsevier Science Publishers B.V., Amsterdam - - Printed in The Netherlands
Feed Intake, Milk Yield and Milk Composition by Replacing Unprotected Fat by Ca-soaps for Dairy Cows JOHN E. HERMANSEN
National Institute of Animal Science, P.O. Box 39, 8830 Tjele (Denmark) (Received 13 February 1987; accepted for publication 23 December 1987)
ABSTRACT Hermansen, J.E., 1989. Feed intake, milk yield and milk composition by replacing unprotected fat by Ca-soaps for dairy cows. Anim. Feed Sci. Technol., 22: 193-202. The effect of substituting traditional animal fat with saponified animal fat was investigated in experiments in 2 commercial herds: (1) a Danish Black and White herd ( 18 cows in mid-lactation per treatment) given a complete ration ad libitum; (2) a Jersey herd (15 cows in mid-lactation per treatment) given fixed amounts of concentrates containingthe fat and given silage ad libitum. In both experiments, the daily allowance of saponified animal fat was lower than the corresponding level of traditional animal fat because of a lower fat content in the saponified product than expected. The degree of saponification was estimated at ~ 70%. In Experiment 1, where the level of experimental fat amounted to 759 and 882 g, respectively, per cow daily, feed intake and milk yield tended to increase and the yield of butter fat was increased significantly (100 g per cow daily ) when using saponified animal fat. Furthermore, the content of linoleic acid in the milk was increased. In Experiment 2, the level of experimental fat was ~ 500 and 600 g, respectively, per cow daily, while the basic ration contained ~ 300 g. No significant effect on yield of milk and butter fat or the content of linoleic acid in the milk was found. It is concluded that the use of saponified animal fat is a means by which the positive effect on milk production of supplementing fat can be prolonged to higher levels of fat in the ration than can be reached with traditional animal fat.
INTRODUCTION
Several reports, summarized by Palmquist (1984a), have shown that the negative effect on rumen fermentation which is seen by feeding unprotected fat is avoided when the fat is given in the form of pre-formed Ca-soaps, which are rather insoluble in the rumen at a normal pH. Similar results have been found with the Na-salt of palm acid oil (Moller, 1986). On the other hand, only a few and small-scale results concerning the effect 0377-8401/89/$03.50
© 1989 Elsevier Science Publishers B.V.
194
on milk yield are available and do not show a consistent effect (Palmquist, 1984b; Chalupa et al., 1985). The aim of the present work was, therefore, to estimate the effect on feed intake and milk yield of replacing traditionally used animal fat (tallow or lard rendering) with the same type of fat given as Casalts. MATERIALSAND METHODS Two experiments in which traditional animal fat was replaced by Ca-soaps of the same type of fat were carried out in 2 commercial herds (tie-stalls) of the breeds Danish Black and White (SDM) and Danish Jersey, respectively. The saponified animal fat was supplied by N.L. Mathiesen, N~erum, Denmark, and the concentrates mixture containing either saponified or traditional animal fat was supplied by A. Toft A/S, Durup, Denmark. Management and feeding were carried out by the herdsmen while the registrations were made by a technician.
Experiment I Thirty-six SDM cows of an average body weight of 520 kg and in Weeks 324 of lactation were paired according to number of lactation, stage of lactation and actual yield of 4% fat-corrected milk, and randomly allotted to 2 treatments. Sixteen of the cows were in their first lactation. For a period of 10 weeks, the 2 groups of cows were given a complete ration ad libitum containing a concentrates mixture with either traditional animal fat or saponified animal fat. On a dry matter basis, the complete ration consisted of 23.4% concentrates (experimental feed), 10.6% chopped NH3-treated straw, 27.4% fodder beets, 21.1% grass silage, 15.1% whole crop barley silage, 0.8% urea and 1.6% minerals. The concentrates mixture consisted of the following ingredients: 50% soyabean meal; 15% barley; 5% cane molasses; 3% albumin; 3% lignosulphonate; 2% minerals; either 22% saponified tallow/lard rendering or 19% tallow/ lard+ 3% CaC03. The concentrates were treated with 0.3% formaldehyde. The complete ration was calculated to contain per kg dry matter (DM) ;0.94 Scandinavian Feed Units (SFU), 170 g crude protein and 7 g of Ca. Daily milk yield and feed intake were determined individually over 1 day and night, 5 and 8 times, respectively, through the experimental period. In relation to milk recording, a common milk sample from each group of cows was produced for determining iodine value and, the last 2 times, fatty acid composition of the milk. Gain was determined by weighing the cows on 2 successive days at the beginning and end of the experiment.
195
Experiment 2 Forty-five Jersey cows in Weeks 6-21 of lactation and with an average body weight of 368 kg were selected. The cows were blocked in groups of 3 and randomly allocated within each block to one of the following 3 treatments (types of concentrates): traditional animal fat, a palmitic and stearic acid-rich type of fat, and for the third group saponified animal fat. For a period of 9 weeks, the cows were given the concentrate mixtures consisting of 50% cotton seed meal, 15% soya-bean meal, 5% molasses, 5% meat bone meal, 3% albumin, 3% lignosulphonate, 2% minerals and 15% traditional animal f a t + 2% CaCO3 or 15% palmitic/stearic fat-mixture+2% CaCO~ or 17% Ca-saponified animal fat, respectively. The concentrate mixtures were treated with 0.3% formaldehyde. The concentrates were given in fixed and equal amounts to all the cows (3.7 kg DM per cow daily). In addition, the cows were given fodder beets (5.6 kg DM) and brewers grain (2.4 kg DM) in fixed amounts, and silage and hay ad libitum - - the simplified feeding system (Ostergaard, 1979). Milk yield, milk composition and gain were recorded in the same way as in Experiment 1. Feed intake (excluding intake of experimental feed) was recorded for the herd (110 cows) as a whole.
Analytical procedures The feed was analysed according to conventional methods described by Jakobsen and Weidner (1973). Fatty acid composition in feed and milk was determined by gas chromatography, including an internal standard of C15:0 and C 17:0. Buffer solubility and nylon bag degradability of the concentrate protein was determined as described by Madsen and Hvelplund (1985).
Statistical procedures The effect of treatment on yield, gain and, in the SDM herd, feed intake on average for the experimental period was analysed for the 2 herds using the following model: Y= average + bl" (no. of days in lactation at start) + b2" (yields in 4% fat-corrected milk at start) + source of fat + residual for the individual cow Fatty acid composition and iodine value of the milk were evaluated by a t-test of the differences between treatments on the day of collection.
196 RESULTS
Experiment I The chemical composition of the concentrates is given in Table 1. The fat content of the concentrates containing saponified animal fat was lower than planned, probably because the fat content in the Ca-saponified product was lower than expected when the composition of the concentrate mixture was planned. The resulting difference in fatty acid content, expressed as the sum of the measured fatty acids given in Table 1, was not negligible. The degree of saponification was evaluated as the difference between the ether extract part and the Stoldt fat part. The ether extract amounted to 5.4% of DM, which would give a saponification of ~ 72%. Feed intake, yield and gain are given in Table 2. It appears from Table 2 that feed intake tended to increase when using saponified fat. The total fat intake was, however, lowest in that group because of the lower fat content in the concentrates. The cows given saponified fat yielded 100 g butterfat more per TABLE1 Chemical composition of the concentrates, Experiment 1 Saponified animal fat
Traditional animal fat
Dry matter (%)
88.0
87.4
Composition of DM Crude protein (%) Stoldt fat (%)2 Crude fibre (%) Ca (%)
29.7 19.3 5.1 1.9
29.2 23.7 5.2 1.5
Identified fatty acids (distribution) (%)1 C12:0 C14:0 C14:1 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3
Sum ~Weight % of methyl esters; 0 =trace. 2Ether extract after hydrolysis with HCI.
0.0 0.4 0.1 4.0 0.5 2.5 4.8 0.9 0.3
13.5
(0) (3) (1) (30) (4) (18) (36) (6) (2)
0.1 0.3 0.1 4.3 0.5 2.8 7.5 2.1 0.3
18.0
(i) (2) (o) (24) (3) (16) (41) (11) (2)
197 TABLE 2 Feed intake, yield and gain per cow daily by the use of saponified animal fat or traditional animal fat, Experiment 1 Saponified fat Feed intake Total DM (kg) Total SFU 1 Stoldt fat in concentrates (g) Yield Milk (kg) Fat (g) Fat (%) Protein (g) Protein (%) 4% fat corrected (kg) Gain (g)
Traditional fat
Difference S- T
P value
0.9 0.6 - 123
(0.11)
16.8 15.5 759
15.9 14.9 882
24.5 1003 4.09 757 3.08 24.8
23.2 903 3.89 708 3.05 22.8
1.3 100 0.20 49 0.03 2.0
(0.13) ( <0.01 ) (0.05) ( < 0.01 )
124
107
(0.10)
231
-
1Scandinavian feed unit.
TABLE 3 Composition of milk fat using saponified animal fat or traditional animal fat, distribution of major fatty acids Saponified fat
Traditional fat
Difference S- T
Weight % of methyl esters C12:0 C14:0 C14:1 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3
2.4 10.4 1.5 34.1 3.2 10.7 33.1 3.9 1.0
2.4 10.5 1.7 34.5 3.1 11.5 33.0 2.4 0.9
0.0 --0.1 --0.2 -0.4 0.1 -0.8 0.1 1.5" 0.1
Iodine value
35.3
33.5
1.8
*P < 0.05.
198 day because o f a higher milk yield as well as a higher fat c o n t e n t o f t h e milk. T h e r e was also a t e n d e n c y t o w a r d s i n c r e a s e d gain with the use of saponified fat. T h e c o m p o s i t i o n of milk fat c o n t a i n i n g > 10 c a r b o n s is given in T a b l e 3, f r o m w h i c h it can be seen t h a t o n l y small differences in milk f a t t y acid comp o s i t i o n were observed, b u t t h e c o n t e n t o f linoleic acid was actually raised by t h e use of saponified fat.
Experiment 2 T h e chemical c o m p o s i t i o n s of t h e c o n c e n t r a t e m i x t u r e s are given in T a b l e 4. As in E x p e r i m e n t 1, t h e fat c o n t e n t of t h e soap c o n c e n t r a t e was less t h a n p l a n n e d , p r o b a b l y for t h e same reason. T h e e t h e r e x t r a c t p a r t of t h e c o n c e n t r a t e s c o n t a i n i n g saponified fat acTABLE 4 Chemical composition of the concentrates, Experiment 2 Saponified animal fat
Traditional animal fat
Saturated fat
Dry matter (%)
88.9
89.6
88.5
Composition of DM Crude protein (%) Crude fibre (%) Stoldt fat (%) Ca (%)
32.3 11.1 15.8 2.0
33.7 11.6 19.0 1.7
31.7 11.0 18.9 1.7
Identified fatty acids (distribution) (%) C12:0 0.0 ( 0 ) C14:0 0.3 ( 3 ) C14:1 0.0 (O) C16:0 2.9 (25) C16:1 0.5 ( 5 ) C18:0 2.0 (18) C18:1 4.4 (38) C18:2 1.2 (10) C18:3 0.2 ( 1 )
0.0 ( 0 ) 0.2 ( 2 ) 0.0 (O) 3.3 (24) 0.4 ( 3 ) 2.2 (15) 5.9 (42) 1.8 (13) 0.2 ( 1 )
O.0 ( 0 ) 0.3 ( 2 ) 0.0 (O) 4.2 (26) 0.1 ( 1 ) 9.0 (56) 1.2 ( 7 ) 0.9 ( 6 ) 0.4 ( 2 )
Sum
11.5
14.0
16.1
Nylon bag degradability of protein (8%)
27
29
33
~Weight % of methyl esters; 0 = trace.
199 TABLE 5 Milk yield and gain given traditional animal fat, saponified animal fat or saturated fat in the concentrates, per cow daily Saponified animal fat Milk (kg) Fat (g) Fat (%) Protein (g) Protein (%) 4% fat corrected (kg) Gain (g)
Traditional animal fat
Saturated fat
P value for effect
18.1
18.5
17.3
0.33
1111 6.16
1115 6.03
1103 6.38
0.94 -
670 3.73
681 3.68
657 3.79
0.58 -
23.9
24.1
23.5
0.68
336
265
260
0.44
TABLE 6 Composition of milk fat at different fat sources in concentrates, distribution of major fatty acids, Experiment 2 Saponified animal fat
Traditional animal fat
Saturated fat
Weight % of methyl esters C12:0 C14:0 C14:1 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3
4.4 12.3 1.2 37.4 2.4 12.4 22.7 4.3 0.9
4.4 12.0 1.2 37.3 2.4 13.6 23.6 4.2 1.0
4.7 12.5 1.1 37.7 2.1 14.4 20.7 3.8 0.7
Iodine value
31.1
30.4
27.8
c o u n t e d for 5.4%. E s t i m a t e d o n t h e basis of the difference b e t w e e n t h e e t h e r e x t r a c t p a r t a n d the S t o l d t fat, t h e s a p o n i f i c a t i o n c a n be e s t i m a t e d at ~ 65%. T h e c o n t e n t of identified f a t t y acids was h i g h e s t in t h e m i x t u r e with satur a t e d fat, b u t it is n o t clear w h e t h e r this result reflects a n a c t u a l l y h i g h e r f a t t y acid c o n t e n t in t h e mixture, as t h e S t o l d t fat c o n t e n t was t h e s a m e as in the m i x t u r e c o n t a i n i n g t r a d i t i o n a l a n i m a l fat. O t h e r i n v e s t i g a t i o n s have revealed
200 that typical, Danish tallow/lard rendering may contain up to 4% of fatty acids with > 18 carbons. As mentioned earlier, the silage intake for the respective groups of cows was not recorded. The average silage intake was estimated at 3.3 kg DM per cow daily and as a consequence, their total intake can be estimated at 15 kg DM, 15 SFU and 830 g fatty acids for the treatment with traditional animal fat, and 527 g fatty acids from the experimental feed. Milk yield and gain are given in Table 5. No significant effect of type of fat was found. The milk composition is given in Table 6. No major differences were found in the saponified fat compared to traditional animal fat. Compared to traditional animal fat, the saturated mixture tended to increase the proportion of C12:0, C14:0, C16:0 and C18:0 at the expense of C18:1 and C18:2, resulting in a markedly reduced iodine value in the butterfat. DISCUSSION The response of the saturated fat (C16:0 and C18:0) in Experiment 2 was very much like the response found in earlier experiments (Hermansen, 1989), i.e. a negative influence on milk yield, but a markedly increased fat content of the milk at this level of inclusion. The experiments did not succeed in showing a consistent effect on milk yield of Ca-soaps compared to traditionally used animal fat. The fact that the Casoap concentrates had a lower fat content than the traditional animal fat and the planned level may have affected the interpretation of the experiments. In Experiment 1, the total intake of animal fat was 880 g per cow. In addition to the fatty acids in the basic ration ( ~ 120 g), the total level of fat (64 g kg -1 DM) is so high that a negative influence on milk fat yield is expected (Ostergaard et al., 1981; Hermansen, 1989). In this case, the use of saponified animal fat has stimulated the milk fat percentage and the milk fat yield. Furthermore, the milk protein yield was stimulated, but this effect must be related to the lower fat allowance with saponified fat, which has resulted in a higher intake of nutrients available for the milk protein synthesis, and it is not reasonable to relate this observation to the type of fat. In Experiment 2, where no significant effect was observed although the fat content of the milk tended to increase with the use of saponified fat, the total fat allowance was also high ( ~ 900 g per cow) because of the use of brewers' grain in the basic ration. The fat in question was, however, considerably lower than in Experiment 1. A total of 85% of the concentrate fat was a result of the experimental manipulation. This amounted to ~ 600 g of animal fat per cow against 820 g in Experiment 1. Because of the use of beet-top silage in Experiment 2, the daily allowance of Ca can be estimated at 1.0% of total DM, which is considerably above Danish standards and the level used in Experiment 1
201 Z (0.7% of DM, corresponding to Danish standards). Even if it is shown that the addition of Ca to the ration cannot fully reverse the negative effect of fat on fermentation (El-Hag and Miller, 1972) and that preformed Ca-soaps are superior to conventional f a t + a d d e d Ca (Palmquist et al., 1985), it has also been shown that the addition of Ca to a ration rich in fat does have a positive influence on rumen fermentation (Jenkins and Palmquist, 1980, 1982; Palmquist and Conrad, 1980; Palmquist and Jenkins, 1980). Therefore, Palmquist (1982) recommends a level of ~ 1.0% Ca in the total DM ration when rich in fat to secure the natural soap formation in the rumen. This means that the difference in response in Trials 1 and 2 may be caused by the smaller amount of fat used in Experiment 2 and/or that the diet conditions in Experiment 2 were relatively in favour of the traditional animal fat. The method of recording milk composition and the lack of determination of the short-chain fatty acids made it impossible to discuss the quantitative transfer of fatty acids to milk. However, in Experiment 1 the proportion of linoleic acid in the milk increased significantly (from 5% of the C18 fatty acids to 8% ) despite a markedly lower allowance of C18:2 and a lower relative proportion of C18:2 of the C18 fatty acids in the concentrates. In Experiment 2 this effect was not seen, probably because of the smaller amount of experimental fat in question and the fact that the C18:2 content of the milk in general was high as a result of the use of brewers' grain. CONCLUSIONS
The present results show that at a high level of fat inclusion in the diet, where a negative effect of traditional animal fat is expected, the use of saponified animal fat will increase milk and butterfat yield markedly. On the other hand, at a moderate level of fat inclusion no such positive effect can be expected. Therefore, it seems reasonable to consider saponified fat as a means by which the positive effect of traditional animal fat on milk production at moderate levels can be prolonged to higher levels of fat in the ration. The results obtained do not allow a direct conclusion on the effect of an increased allowance of saponified fat. However, based on the similarity in response in the present Experiment 1 and the results of Hermansen (1989) concerning increasing allowance of saturated fat, it seems reasonable to suggest a response of ~ 100 g of butterfat per cow daily when increasing the daily allowance of total fat from 45 to 75 g k g - 1 DM by the use of saponified fat.
REFERENCES Chalupa, W., Vecchiarelli,B., Sklan, D. and Kronfeld, D.S., 1985. Responses of tureen microorganism and lactating cows to calcium salts of long chain fatty acids. In: Abstracts for the
202 Eightieth Annual Meeting of the American Dairy Science Association, June 1985. J. Dairy Sci., 68: 110. El-Hag, G.A. and Miller, T.B., 1972. Evaluation of whisky distillery by-products. VI. The reduction in digestibility of malt distillers grains by fatty acids and the interaction with calcium and other reversal agents. J. Sci. Food Agric., 23: 247-258. Hermansen, J.E., 1989. Feed intake and milk yield at increasing supplement of a palmitic and stearic acid-rich type of fat in comparison with animal fat. Anita. Feed Sci. Technol., 22: 179191. Jakobsen, P.E. and Weidner, K., 1973. Chemistry of feedstuffs and animals. Veterinary Faculty for FAO Fellows, Royal Veterinary and Agricultural University, Copenhagen, 69 pp. Jenkins, T.C. and Palmquist, D.L., 1980. Effect of added fat and calcium on rumen lipid metabolism of Holstein cows. J. Dairy Sci., 63 (Suppl. 1 ): p. 153. Jenkins, T.C. and Palmquist, D.L., 1982. Effect of added fat and calcium on in vitro formation of insoluble fatty acid soaps and cell wall digestibility. J. Anim. Sci., 55: 957-963. Madsen, J. and Hvelplund, T., 1985. Protein degradation in the rumen. A comparison between in vivo, nylon bag, in vitro and buffer measurements. Acta Agric. Scand., Suppl. 25: 103-123. Moller, P.D., 1986. Undersogelser over oms~etning af Ca-sseber og frie fedtsyrer i mave-tarmkanalen hos kv~eg. Natl. Inst. Anita. Sci., Copenhagen, Short Communication No. 628, 4 pp. Ostergaard, V., 1979. Strategies for concentrate feeding to attain optimum feeding level in high yielding dairy cows. Natl. Inst. Anim. Sci., Copenhagen, Rep. 482, 138 pp. Ostergaard, V., Danf~er, A., Daugaard, J., Hindhede, J. and Thysen, I., 1981. The effect of dietary lipids on milk production in dairy cows. Natl. Inst. Anita. Sci., Copenhagen, Rep. 508, 140 pp. Palmquist, D.L., 1982. Fat in dairy rations. Feed Int., pp. 46-49. Palmquist, D.L., 1984a. Use of fats in diets for lactating dairy cows. In: J. Wiseman (Editor), Fats in Animal Nutrition. Butterworths. Palmquist, D.L., 1984b. Calcium soaps of fatty acids with varying unsaturation of fat supplements for lactating cows. Can. J. Anim. Sci., 64 (Suppl.): 240-241. Palmquist, D.L. and Conrad, H.R., 1980. High fat rations for dairy cows. Tallow and hydrolized blended fat at two intakes. J. Dairy Sci., 63: 391-395. Palmquist, D.L. and Jenkins, T.C., 1980. Fat in lactation rations: review. J. Dairy Sci., 63: 1-14. Palmquist, D.L., Joyner, A.E. and Jenkins, T.C., 1985. Effect of dietary calcium source on rate of insoluble soap formation in the rumen and digestibility of fiber in sacco. J. Dairy Sci., 68 (Suppl. 1 ): 111.