Effects of Feeding Lactating Dairy Cows Diets Containing Whole Soybeans and Tallow1 D. J. SCHAUFF? J. P. ELLIOlT, J. H. CLARK? and J. K. DRACKLEY Department of Animal Sciences University of Illinois
Urbana 61801 ABSTRACT
Four multiparous Holstein cows averaging 133 d postpartum and fitted with ruminal cannulas were utilized in a 4 x 4 Latin square design to investigate the effects of feeding diets containing whole soybeans and tallow. Treatments were 1) control, no added fat; 2) control and 10% whole raw soybeans; 3) control, 10% whole raw soybeans, and 2.5% tallow; and 4) control, 10%whole raw soybeans, and 4.0% tallow. Cows were fed for ad libitum intake a diet of alfalfa haylage, corn silage, and concentrate (45550, DM basis). Intakes of DM and production of milk, milk CP, milk SNF, and 4% FCM were not affected by feeding supplemental fat. hoduction of milk fat and weight percentages and yields of long-chain fatty acids in milk fat were increased, whereas weight percentages and yields of short- and medium-chain fatty acids were decreased by feeding supplemental fat. Digestibilities of DM, OM, energy, cellulose, and fatty acids were decreased slightly when fat was added to the diet, but utilization of energy and N for production of milk was not altered. Supplemental fats increased concentrations of NEFA and cholesterol in plasma. These data indicate that relatively large amounts of unprotected fat
can be added to the diet of lactating dairy cows without deleterious effects on milk composition, ruminal fermentation, or nutrient digestibilities. (Key words: feeding lactating d a q cows, whole soybeans, tallow, animal fats)
Abbreviation key: A-V = animal-vegetable, DE = digestible energy, ME = metabolizable energy, PE = partial efficiency of energy utilization for milk production, WSB = whole soybeans. INTRODUCTION
In early lactation, dairy cows have a large requirement for energy, but intake of energy may be limited by capacity for DMI. Addition of fat sources, such as whole oilseeds or tallow, to the diet may improve the energy status of high producing dairy cows. Increasing dietary intake of long-chain fatty acids should improve the metabolic efficiency of energy utilization for milk production (21). Preformed fatty acids of dietary origin can be incorporated directly into milk fat, which decreases energy expended to synthesize fatty acids and thereby spares energy for other productive functions in the mammary gland. Several studies have investigated the effects of feeding either whole soybeans (WSB) or tallow to lactating dairy cows. Ruminal acetate to propionate ratios (18, 26) and digestibilities of N (36) and DM (26) were decreased by feeding raw WSB or heated WSB at approxiReceived October 2, 1991. Accepted February 26, 1992. mately 20% of the dietary DM, whereas in lsupported in part by the university of ~llinoisAH- other studies deleterious effects of feeding cultural Experiment Station and a gift from Church and WSB at 15 to 20% of the dietary DM on Ihvi ht Co., Inc., Princeton, NJ. %rotein Blenders, 2420 Old Highway 218 South,Po ruminal fermentation (22, 36) and nutrient diBox 2090, Iowa City, IA 52244. gestibilities (29) were minimal. Addition of as 3~ddresscorrespondence to: J-Y H. CMC, Univer- much as 5% tallow to diets for lactating dairy sity of Illinois, Department of Animal Sciences. 264 Animal Sciences Lab, 1207 West Gregory Drive, Urbana, IL cows did not alter greatly ruminal fermentation (30, 31, 37), total tract nutrient digestibilities 61801. 1992 J Dairy Sci 75:1923-1935
1923
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SCHAUPP ET AL.
TABLE 1. Ingredient arid nutrient compositions of total mixed diets (dry h i s ) containing whole soybeans (WSB) and mow.
Item
Conk01
Control + WSB
Treatnacnts conlrol + WSB + 25% mow
Control + WSB + 4.0% tallow
(96)
Lngredient 45.00 Alfalfa haylage 5.00 Corn silage Ground shelled corn 2755 Soybean meal (48% CP) 7.00 5.00 Soybean hulls Whole raw soybeans Tallow' 4.50 Meat and bone meal Distillers dried grains with solubles 5.50 .15 Mineral and vitamin mixture2 .30 Scdim chloride ... Magnesium oxide Nutrient composition 71.7 DW % 92.0 OM, 96 20.6 CP, % 23.2 ADF, % 35.9 NDF, % 1.2 ca, % 3.1 Fatty acids, % Gross energy, Mcavkg 458
... ...
45.00 5.00 29.45
... ...
10.00
...
4.50 5.50 .15 .30 .10 71.8 92.1 202 212 33.4 1.3 5.2 4.72
45.00 5.00 26.95
45.00 5.00 25.45
10.00 2.50 4.50 5.50 .30 .10
10.00 4.00 4.50 5.50 .15 .30 .10
72.1 92.3 20.1 21.0 335 1.1 7.1 4.87
72.2 92.3 19.7 21.o 33.3 12 7.9 4.92
... ...
.IS
... ...
'Tallow marketed as Max Fat, Max-Fat Corporation, Green Bay, WI. kontains: 5.0% Mg, 7.5% K 10.0% S; 3.0% Zn; 3.0% Mn; 2.0% Fe; .5% CU; .015% Se; 2000 N of vitamin Ng 662 lU of vitamin D/g 8 IU of vitamin Wg.
(30), or ruminal disappearance of NDF from polyester bags (31). Many high producing commercial dajl herds have successfully utilized tallow and oilseeds (including raw WSB) in their diets (35). Because unprotected fats, such as oilseeds and tallow or other animal fats, usually are the cheapest sources of fat, there is great interest in maximizing their utilization in diets for dairy cattle. The optimal amounts of whole oilseeds or tallow to feed to high producing dairy cows to enhance lactational performance without causing deleterious effects on ruminal fermentation, nutrient digestibilities, energy and N utilization, milk production, or milk composition have not been determined Furthermore, information is needed about combining oilseeds and tallow in diets of dairy cows. Therefore, the objective of this study was to investigate the effects of feeding diets containJournal of Dairy Science Vol. 75, No. 7, 1992
ing WSB and tallow on ruminal fermentation, apparent total tract nutrient digestibilities, energy and N utilization, milk production, and milk composition. MATERIALS AND METHODS Experimental Design, Diets, and Management of Cows
Four multiparous Holstein cows with ruminal cannulas and averaging 133 d postpartum were used in a 4 x 4 Latin square with 21d periods. Each period consisted of 14 d of adjustment to treatments followed by 7 d of sample collection. The four treatments were 1) control, no added fat; 2) control and 10% raw WSB; 3) control, 10% WSB, and 2.5% tallow (Max Fat, Max-Fat Corp., Green Bay, WI); and 4) control, 10% WSB, and 4.0% tallow. Ingredient and nutrient compositions of the
FEEDING WHOLE SOYBEANS AND T U O W
diets are shown in Table 1. Ingredients were supplemented to meet the stated nutrient requirements for lactating dairy cows (27). Soybean hulls were added to the control diet to equal fiber provided by WSB in the other diets. Cows were fed and milked daily at 0500 and 1700 h and were weighed on 3 consecutive d before and after each fecal and urine collection period. Cows were allowed to exercise daily from 0600 to 0800 h, except during the last 5 d of each period when feces and urine were being collected. Nutrient intakes, Milk Production, and Milk Composition
1925
assuming that milk fat is 100% triglycerides and that there are 3 mol of fatty acids/mol of glycerol. Thus, 100 mol of fatty acids represent 33.3 mol of trigylceride. The weight that each of the fatty acids and glycerol contribute to the 33.3 mol of triglyceride was calculated after the molecular weight of each fatty acid was adjusted for removal of hydrogen and oxygen that are lost when the fatty acid is esterified to glycerol. The weights of the individual fatty acids and glycerol were converted to a relative weight percentage. The relative weight percentage was multiplied by yield of fat in milk to determine the yield of individual fatty acids and glyceroL
Diets were fed twice daily to cows as TMR Ruminal Fermentation in amounts to ensure 10% orts, and Dh4I were On d 20 of each period, ruminal fluid (40 measured daily. Samples of the dietary ingrediml) was collected from each cow via a suction ents and orb for each cow were obtained durpump at hourly intervals for 12 h after the a m ing the last 5 d of each period and were composited on a proportional basis according feeding. Ruminal fluid pH was determined imto amounts of feed offered and refused each mediately by using a glass electrode. Samples day. Composite samples were dried at 55"C, were acidified to pH 2 with 50% H2SO4 and ground in a Wiley mill with a 1-mm screen centrifuged at 27,000x g for 10 min, and the (Arthur H. Thomas, Philadelphia, PA), and supematant was frozen until analyzed for conanalyzed for contents of DM, OM (600'C for 8 centrations of VFA and ammonia N. Volatile h), CP (l), ether extract (l), energy (1261 fatty acids in the supernatant were determined Isoperibol Calorimeter, Parr Instrument Co., according to procedures of Klusmeyer et al. Ca (Perkin-Elmer Corp.,Norwalk, (20)by using an automated gas chromatograph Moline, E), CT), fatty acids (38), NDF (15), ADF (15), (Varian model 4600,Palo Alto, CA). Concencellulose (15), hemicellulose (NDF minus trations of ammonia N were determined acADQ, and soluble residue (neutral detergent cording to procedures of Chaney and Marbach solubles minus CP and ether extract). (3,as modified by Cotta and Russell (9). Milk weights were recorded daily at each milking. Milk samples were taken at each Total Tract Apparent Nutrient milking during the last 7 d of each period and Digestibilities and Energy composited daily for each cow according to and N Utilization milk production. Samples of milk were presemed with 2-bmmo-2-nitropropane-1,3 Total tract apparent nutrient digestibilities diol and stored at 4°C until a n a l y d for con- and energy and N utilization were determined tents of SNF (16), protein (l), fat [Babcock by total collection of feces and urine on d 17 method (l)], and energy (1261 Isoperihl Cal- through 21 of each period. Urine was collected orimeter, Pan Instrument Co.). Milk fat from via indwelling urinary catheters into polyethylthe Babcock procedure was stored frozen at ene containers, which contained 200 ml of -20°C until the time of fatty acid analysis. concentrated HCl to minimize loss of volatile Fatty acids in milk fat were analyzed utilizing materials. Urine was weighed, and 5% of the the procechues of Sukhija and Palmquist (38), daily urine output was stored at 4'C until the except that an external standard rather than an end of each period. Daily samples of urine internal standard was used to quantify the pro- then were composited and frozen at -20°C portions and yields of fatty acids in milk (4). until analyzed. Three percent of the daily fecal Glycerol in milk was calculated (D. M. output for each cow was stored frozen. Daily Barbano, 1990, personal communication) by fecal samples for each cow then were thawed, J o d of Dairy Science. Vol. 75, No. 7, 1992
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SCHAUPP ET AL.
composited by period, dried (55'C for 48 h), urea N (5). Concentration of NEFA in plasma was m e a s d by using a modification (12) of and ground through a 1-mm screen. Feces were analyzed for contents of DM, a commercial kit (NEFA-C, Wako Chemical OM, CP, ether extract, energy, Ca,fatty acids, Co. USA, Dallas, TX). NDF, ADF, cellulose, hemicellulose, and soluble residue as described for feed samples. Statistlcal Anaiysls Results from these analyses were used to calRepeated measurements (e.g., hourly mid a t e apparent total tract nutrient digestibility coefficients (34). The amounts of digestible nal measurements) were reduced to period soluble residue, hemicellulose, and cellulose means for each cow before statistical analyses. were used to calculate methane production by Data were analyzed by ANOVA for a Latin using the multiple regression equation deve square design using the general linear models procedure of SAS (14, 33). The treatment deloped by Moe and Tyrrell (24): sign was balanced for residuals (Le., carry-over effects) so that each treatment was preceded in methane production, McaVd = the design an equal number of times by each .439 + .273 (digested soluble residue, kg/d) of the other treatments (8). Residual effects + 3 2 (digested hemicellulose, kg/d) were not significant for any variables, so the + 1.393 (digested cellulose, kg/d). residual term was dropped from the model, and Urine was analyzed for contents of N (1) degrees of f r d o m were pooled with the error and energy (1261 Isoperibol Calorimeter, Parr term (14). Least squares means then were genInstrument Co.) to determine N utilization and erated (14) and are presented throughout. Ormetabolizable energy (ME).Apparent ME in- thogonal comparisons for treatment means take was estimated by subtracting gross energy were 1) control versus all treatments with lost in feces, urine, and methane from gross added fat, 2) WSB versus WSB plus tallow, energy in feed consumed. Metabolizable en- and 3) 2.5% tallow versus 4.0% tallow. Comergy intake above maintenance requirements parisons with P e .05 were considered to be (Le., ME available for milk production) was significant. estimated according to NRC (27) and was RESULTS AND DISCUSSION adjusted for changes in BW by using a value of 6 Mcal of ME/kg of BW change (27). Partial efficiency of energy utilization for milk Nutrient Composition of the Total production (PE) was calculated according to Mixed Diets the equation of Kronfeld et al. (21), where PE, Nutrient composition of diets is shown in % = [(milk energy)/(ME for milk - energy in Table 1. Au. diets were similar in contents of BW change)] x 100. Retained N was calcu- DM, OM, and Ca. Concentration of CP in the lated by subtracting N in feces, urine, and milk diets ranged from 19.7 to 20.6%. Dietary confrom N intake. Productive N was calculated as centrations of ADF and NDF were about 2 the sum of N retained in the body and N percentage units higher for the control diet secreted in milk. than for the other three diets, probably because soybean hulls in the control diet supplied more ADF and NDF than did WSB included in the Blood Sampling and Analyses other treatments. Contents of gross energy and Samples of blood were obtained by jugular fatty acids increased as additional fat was venipuncture from each cow 3 h after the a.m. added to the diets. The fatty acid compositions feeding on d 21 of each period. Blood was of tallow and WSB are shown in Table 2; mixed immediately with Na-EDTA (.l% final values are. similar to those reported by others concentration), and plasma was collected after (26, 30). centrifugation. Plasma was divided into aliquots and stored at -20'C until analyzed for DMI and Mllk Production and Composition concentrations of glucose (Sigma kit number Dry matter intake was not affected by sup315, Sigma Chemical Co., St. Louis, MO), total cholesterol (Sigma kit number 352), and plemental fat (Table 3). This agrees with data Journal of Dairy Science Vol. 75. No. 7, 1992
FEEDING WHOLE SOYBEANS AND TALLOW
TABLE 2. Patty acid composition of tallow and raw whole Soybeans. Raw whole
Fattv acid
SOVbeans
Tallow
c12:o
1.06 .07 11.30 .03 3.60 21.58 55.40 6.96
.07 320 24.80 5.32 14.50 45.94 5.92 25
c140 C160 C161 C180 C181 C182 c1&3
from other studies in which as much as 5% added tallow or protected tallow (30, 39) or 7.5% added yellow grease (11) were fed to lactating dairy cows. In contrast, DMI were decreased from 1 to 2 kg/d when loo0 g/d of hydrolyzed animal-vegetable (A-V) fat (23) or either 841 or 964 g/d of tallow were fed to lactating dairy cows (7). In the latter trial, the amount of tallow fed to the cows may have been excessive, because they consumed relatively small amounts of feed, and milk production was relatively low. Production of milk was not altered significantly by treatment (Table 3). In previous experiments, animal fats or raw WSB often did not increase milk production when the studies were short-term Latin square or switchback designs or when cows were producing less than 30 kg/d of milk (26, 29, 30, 36, 37). In
1927
other short-term trials, however, tallow (3) or yellow grease (11) inireas4 milk produition. In longer term (18 wk) experiments, milk production was increased by 2 to 3 kg/d when protected tallow (39) or encapsulated tallow (17) was fed to dairy cows. Additional longterm trials with high producing cows in early lactation are needed to determine the magnitude of increase in milk production that can be obtained when animal fats are fed to dairy cows. Milk fat percentage tended to increase (P = .06)when fat was fed to the cows, especially when both tallow and WSB were fed (Table 3). Milk fat yield also tended (P = .06) to increase when cows were fed fat (Table 3). Changes in milk fat percentages have been variable when cows were fed animal fats. Milk fat percentage was increased fiom .3 to .8 percentage units by feeding tallow (3, 7) or yellow grease (6); decreased .4 to .7 percentage units by feeding 5% tallow (39), 7.5% yellow grease (ll), or 5% yellow grease (19); or unchanged by feeding animal fats (17, 23, 30, 37). Adding more than 5% animal fat to the diet, especially the more unsaturated animal fats such as yellow grease or A-V fat, is more likely to depress milk fat percentage than adding either more saturated fat or smaller amounts of fat to the diet. Milk fat percentage and ruminal acetate to propionate ratios were decreased when 5% yellow grease was added to the diet compared with a diet that contained 5% hydrogenated yellow grease (19).
TABLE 3. DMI, milk production, and milk composition for cows fed whole soybeans (WSB) and tallow.
Treatments Control
Item
Control
Control + WSB
DM& W d Milk. kgld % Fat, kgld 4% FCM, kg/d
22.2 30.5 3.34 1.02 27.5 3.14 .96 7.94 2.42
21.8 30.9 3.41 1.05 28.2 3.12 .96 7.86 2.43
CP, %
a,W d SNF, % SNF, kgld
Control
+ WSB + 2.5% tallow
+ WSB + 4.0% tallow
SEM
21.7 30.5 3.56 1.08 28.4 3.13 .95 7.67 2.33
21.4 29.7 3.52 1.05 27.5 3.13 .93 7.81 2.32
.6 .9 .06 .02 .6 .02 .03 .ll .07
kontrol v e m fat sources (P = .MI. *WSB vefsus WSB and tallow '2( = .11). Journal of Dairy Science Vol. 75, No. 7. 1992
1928
SCHAUPP ET AL.
Yields and percentages of protein and SNF in milk were not changed by treatment (Table 3), which agrees with data from other expeiments in which raw WSB or animal fats were fed to dairy cows (29, 30). In many other trials, however, milk protein percentage was decreased .1 to .2 percentage units by raw WSB (26, 36) or animal fats (6, 7, 10, 11, 17, 19) fed to dairy cows. The contents of casein and whey proteins in milk were decreased, and there was a trend for an increase in the percentage of NPN in milk when 3.5 to 7.5% yellow grease was added to diets of dairy cows (6, 10, 11). The mechanism for the decrease of milk protein percentage that often occurs when fat is fed to dairy cows remains undetermined. Composition of milk fat (weight percentages) and yields of individual fatty acids in milk fat are shown in Tables 4 and 5. Diets containing supplemental fat did not affect the weight percentage (Table 4) or yield (Table 5) of butyric acid in milk fat. Adding fat to the diet decreased the weight percentages and Yields of c 6 0 , c8:0, c 1 0 0 , C12:Os C14:Ov c 1 4 1 , and C15:o fatty acids in milk fat. The weight , C10.0, percentages and yields of C ~ Oc8:0, C12:0, and C140 fatty acids decreased further
when tallow was added to the diets. Addition of dietary fat decreased the weight percentages and yield of c16:O; however, WSB resulted in larger decreases than did the combinations of WSB and tallow. The greater content of C 1 6 0 in tallow than in soy oil may have provided more C160 for incorporation into milk. Fat supplementation to the diet did not affect weight percentages and yields of C1e. and C17:o fatty acids; however, weight percentages and yields of C16. and C17:o fatty acids were increased when cows were fed WSB and tallow when compared with WSB. Weight percentages and yields of c18:O in milk were increased by including supplemental fat in the diet; however, increases were less when tallow was added to the diet, especially at 4% of the diet. Weight percentage and yield of c18:1 in milk were increased dramatically by supplemental fat; the greatest increases occurred when both tallow and WSB were included in the diet. Supplementing fat to the diet did not affect weight percentage or yield of c18:2 in milk, but adding tallow to diets containing WSB decreased weight percentage and yield of c18:2 compared with adding only WSB. Weight percentage and yield of c18:3 in milk
TABLE 4. Least squares means for weight percentages of fatty acids and glycerol in milk fat from cows fed whole soybeans (WSB) and tallow. Treatments
Control
+ WSB
Control + WSB + 2.5% tallow
C182
2.7 2.0 1.5 2.7 3.2 11.2 1.2 .8 27.7 2.1 .7 8.3 21.0 2.0
c183
.8
3.0 1.8 1.2 2.1 2.6 9.5 .9 .7 23.6 1.7 .6 11.4 25.2 2.7 .7 12.2
2.6 1.5 .9 1.4 1.6 8.2 .9 .6 25.4 2.2 .7 11.0 28.3 2.0 .6 11.9
Fatty acid
Control
Significance of difference (P)
Control
+ WSB + 4.0%
Control
tallow
SEM
vs. fat
2.6 1.5 .9 1.3 1.7 7.7 .9 .7 25.9 2.7 .7 10.0 29.3 2.0 .3 11.8
.2 .1 .1
Urbana 61801 ABSTRACT
Four multiparous Holstein cows averaging 133 d postpartum and fitted with ruminal cannulas were utilized in a 4 x 4 Latin square design to investigate the effects of feeding diets containing whole soybeans and tallow. Treatments were 1) control, no added fat; 2) control and 10% whole raw soybeans; 3) control, 10% whole raw soybeans, and 2.5% tallow; and 4) control, 10%whole raw soybeans, and 4.0% tallow. Cows were fed for ad libitum intake a diet of alfalfa haylage, corn silage, and concentrate (45550, DM basis). Intakes of DM and production of milk, milk CP, milk SNF, and 4% FCM were not affected by feeding supplemental fat. hoduction of milk fat and weight percentages and yields of long-chain fatty acids in milk fat were increased, whereas weight percentages and yields of short- and medium-chain fatty acids were decreased by feeding supplemental fat. Digestibilities of DM, OM, energy, cellulose, and fatty acids were decreased slightly when fat was added to the diet, but utilization of energy and N for production of milk was not altered. Supplemental fats increased concentrations of NEFA and cholesterol in plasma. These data indicate that relatively large amounts of unprotected fat
can be added to the diet of lactating dairy cows without deleterious effects on milk composition, ruminal fermentation, or nutrient digestibilities. (Key words: feeding lactating d a q cows, whole soybeans, tallow, animal fats)
Abbreviation key: A-V = animal-vegetable, DE = digestible energy, ME = metabolizable energy, PE = partial efficiency of energy utilization for milk production, WSB = whole soybeans. INTRODUCTION
In early lactation, dairy cows have a large requirement for energy, but intake of energy may be limited by capacity for DMI. Addition of fat sources, such as whole oilseeds or tallow, to the diet may improve the energy status of high producing dairy cows. Increasing dietary intake of long-chain fatty acids should improve the metabolic efficiency of energy utilization for milk production (21). Preformed fatty acids of dietary origin can be incorporated directly into milk fat, which decreases energy expended to synthesize fatty acids and thereby spares energy for other productive functions in the mammary gland. Several studies have investigated the effects of feeding either whole soybeans (WSB) or tallow to lactating dairy cows. Ruminal acetate to propionate ratios (18, 26) and digestibilities of N (36) and DM (26) were decreased by feeding raw WSB or heated WSB at approxiReceived October 2, 1991. Accepted February 26, 1992. mately 20% of the dietary DM, whereas in lsupported in part by the university of ~llinoisAH- other studies deleterious effects of feeding cultural Experiment Station and a gift from Church and WSB at 15 to 20% of the dietary DM on Ihvi ht Co., Inc., Princeton, NJ. %rotein Blenders, 2420 Old Highway 218 South,Po ruminal fermentation (22, 36) and nutrient diBox 2090, Iowa City, IA 52244. gestibilities (29) were minimal. Addition of as 3~ddresscorrespondence to: J-Y H. CMC, Univer- much as 5% tallow to diets for lactating dairy sity of Illinois, Department of Animal Sciences. 264 Animal Sciences Lab, 1207 West Gregory Drive, Urbana, IL cows did not alter greatly ruminal fermentation (30, 31, 37), total tract nutrient digestibilities 61801. 1992 J Dairy Sci 75:1923-1935
1923
1924
SCHAUPP ET AL.
TABLE 1. Ingredient arid nutrient compositions of total mixed diets (dry h i s ) containing whole soybeans (WSB) and mow.
Item
Conk01
Control + WSB
Treatnacnts conlrol + WSB + 25% mow
Control + WSB + 4.0% tallow
(96)
Lngredient 45.00 Alfalfa haylage 5.00 Corn silage Ground shelled corn 2755 Soybean meal (48% CP) 7.00 5.00 Soybean hulls Whole raw soybeans Tallow' 4.50 Meat and bone meal Distillers dried grains with solubles 5.50 .15 Mineral and vitamin mixture2 .30 Scdim chloride ... Magnesium oxide Nutrient composition 71.7 DW % 92.0 OM, 96 20.6 CP, % 23.2 ADF, % 35.9 NDF, % 1.2 ca, % 3.1 Fatty acids, % Gross energy, Mcavkg 458
... ...
45.00 5.00 29.45
... ...
10.00
...
4.50 5.50 .15 .30 .10 71.8 92.1 202 212 33.4 1.3 5.2 4.72
45.00 5.00 26.95
45.00 5.00 25.45
10.00 2.50 4.50 5.50 .30 .10
10.00 4.00 4.50 5.50 .15 .30 .10
72.1 92.3 20.1 21.0 335 1.1 7.1 4.87
72.2 92.3 19.7 21.o 33.3 12 7.9 4.92
... ...
.IS
... ...
'Tallow marketed as Max Fat, Max-Fat Corporation, Green Bay, WI. kontains: 5.0% Mg, 7.5% K 10.0% S; 3.0% Zn; 3.0% Mn; 2.0% Fe; .5% CU; .015% Se; 2000 N of vitamin Ng 662 lU of vitamin D/g 8 IU of vitamin Wg.
(30), or ruminal disappearance of NDF from polyester bags (31). Many high producing commercial dajl herds have successfully utilized tallow and oilseeds (including raw WSB) in their diets (35). Because unprotected fats, such as oilseeds and tallow or other animal fats, usually are the cheapest sources of fat, there is great interest in maximizing their utilization in diets for dairy cattle. The optimal amounts of whole oilseeds or tallow to feed to high producing dairy cows to enhance lactational performance without causing deleterious effects on ruminal fermentation, nutrient digestibilities, energy and N utilization, milk production, or milk composition have not been determined Furthermore, information is needed about combining oilseeds and tallow in diets of dairy cows. Therefore, the objective of this study was to investigate the effects of feeding diets containJournal of Dairy Science Vol. 75, No. 7, 1992
ing WSB and tallow on ruminal fermentation, apparent total tract nutrient digestibilities, energy and N utilization, milk production, and milk composition. MATERIALS AND METHODS Experimental Design, Diets, and Management of Cows
Four multiparous Holstein cows with ruminal cannulas and averaging 133 d postpartum were used in a 4 x 4 Latin square with 21d periods. Each period consisted of 14 d of adjustment to treatments followed by 7 d of sample collection. The four treatments were 1) control, no added fat; 2) control and 10% raw WSB; 3) control, 10% WSB, and 2.5% tallow (Max Fat, Max-Fat Corp., Green Bay, WI); and 4) control, 10% WSB, and 4.0% tallow. Ingredient and nutrient compositions of the
FEEDING WHOLE SOYBEANS AND T U O W
diets are shown in Table 1. Ingredients were supplemented to meet the stated nutrient requirements for lactating dairy cows (27). Soybean hulls were added to the control diet to equal fiber provided by WSB in the other diets. Cows were fed and milked daily at 0500 and 1700 h and were weighed on 3 consecutive d before and after each fecal and urine collection period. Cows were allowed to exercise daily from 0600 to 0800 h, except during the last 5 d of each period when feces and urine were being collected. Nutrient intakes, Milk Production, and Milk Composition
1925
assuming that milk fat is 100% triglycerides and that there are 3 mol of fatty acids/mol of glycerol. Thus, 100 mol of fatty acids represent 33.3 mol of trigylceride. The weight that each of the fatty acids and glycerol contribute to the 33.3 mol of triglyceride was calculated after the molecular weight of each fatty acid was adjusted for removal of hydrogen and oxygen that are lost when the fatty acid is esterified to glycerol. The weights of the individual fatty acids and glycerol were converted to a relative weight percentage. The relative weight percentage was multiplied by yield of fat in milk to determine the yield of individual fatty acids and glyceroL
Diets were fed twice daily to cows as TMR Ruminal Fermentation in amounts to ensure 10% orts, and Dh4I were On d 20 of each period, ruminal fluid (40 measured daily. Samples of the dietary ingrediml) was collected from each cow via a suction ents and orb for each cow were obtained durpump at hourly intervals for 12 h after the a m ing the last 5 d of each period and were composited on a proportional basis according feeding. Ruminal fluid pH was determined imto amounts of feed offered and refused each mediately by using a glass electrode. Samples day. Composite samples were dried at 55"C, were acidified to pH 2 with 50% H2SO4 and ground in a Wiley mill with a 1-mm screen centrifuged at 27,000x g for 10 min, and the (Arthur H. Thomas, Philadelphia, PA), and supematant was frozen until analyzed for conanalyzed for contents of DM, OM (600'C for 8 centrations of VFA and ammonia N. Volatile h), CP (l), ether extract (l), energy (1261 fatty acids in the supernatant were determined Isoperibol Calorimeter, Parr Instrument Co., according to procedures of Klusmeyer et al. Ca (Perkin-Elmer Corp.,Norwalk, (20)by using an automated gas chromatograph Moline, E), CT), fatty acids (38), NDF (15), ADF (15), (Varian model 4600,Palo Alto, CA). Concencellulose (15), hemicellulose (NDF minus trations of ammonia N were determined acADQ, and soluble residue (neutral detergent cording to procedures of Chaney and Marbach solubles minus CP and ether extract). (3,as modified by Cotta and Russell (9). Milk weights were recorded daily at each milking. Milk samples were taken at each Total Tract Apparent Nutrient milking during the last 7 d of each period and Digestibilities and Energy composited daily for each cow according to and N Utilization milk production. Samples of milk were presemed with 2-bmmo-2-nitropropane-1,3 Total tract apparent nutrient digestibilities diol and stored at 4°C until a n a l y d for con- and energy and N utilization were determined tents of SNF (16), protein (l), fat [Babcock by total collection of feces and urine on d 17 method (l)], and energy (1261 Isoperihl Cal- through 21 of each period. Urine was collected orimeter, Pan Instrument Co.). Milk fat from via indwelling urinary catheters into polyethylthe Babcock procedure was stored frozen at ene containers, which contained 200 ml of -20°C until the time of fatty acid analysis. concentrated HCl to minimize loss of volatile Fatty acids in milk fat were analyzed utilizing materials. Urine was weighed, and 5% of the the procechues of Sukhija and Palmquist (38), daily urine output was stored at 4'C until the except that an external standard rather than an end of each period. Daily samples of urine internal standard was used to quantify the pro- then were composited and frozen at -20°C portions and yields of fatty acids in milk (4). until analyzed. Three percent of the daily fecal Glycerol in milk was calculated (D. M. output for each cow was stored frozen. Daily Barbano, 1990, personal communication) by fecal samples for each cow then were thawed, J o d of Dairy Science. Vol. 75, No. 7, 1992
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SCHAUPP ET AL.
composited by period, dried (55'C for 48 h), urea N (5). Concentration of NEFA in plasma was m e a s d by using a modification (12) of and ground through a 1-mm screen. Feces were analyzed for contents of DM, a commercial kit (NEFA-C, Wako Chemical OM, CP, ether extract, energy, Ca,fatty acids, Co. USA, Dallas, TX). NDF, ADF, cellulose, hemicellulose, and soluble residue as described for feed samples. Statistlcal Anaiysls Results from these analyses were used to calRepeated measurements (e.g., hourly mid a t e apparent total tract nutrient digestibility coefficients (34). The amounts of digestible nal measurements) were reduced to period soluble residue, hemicellulose, and cellulose means for each cow before statistical analyses. were used to calculate methane production by Data were analyzed by ANOVA for a Latin using the multiple regression equation deve square design using the general linear models procedure of SAS (14, 33). The treatment deloped by Moe and Tyrrell (24): sign was balanced for residuals (Le., carry-over effects) so that each treatment was preceded in methane production, McaVd = the design an equal number of times by each .439 + .273 (digested soluble residue, kg/d) of the other treatments (8). Residual effects + 3 2 (digested hemicellulose, kg/d) were not significant for any variables, so the + 1.393 (digested cellulose, kg/d). residual term was dropped from the model, and Urine was analyzed for contents of N (1) degrees of f r d o m were pooled with the error and energy (1261 Isoperibol Calorimeter, Parr term (14). Least squares means then were genInstrument Co.) to determine N utilization and erated (14) and are presented throughout. Ormetabolizable energy (ME).Apparent ME in- thogonal comparisons for treatment means take was estimated by subtracting gross energy were 1) control versus all treatments with lost in feces, urine, and methane from gross added fat, 2) WSB versus WSB plus tallow, energy in feed consumed. Metabolizable en- and 3) 2.5% tallow versus 4.0% tallow. Comergy intake above maintenance requirements parisons with P e .05 were considered to be (Le., ME available for milk production) was significant. estimated according to NRC (27) and was RESULTS AND DISCUSSION adjusted for changes in BW by using a value of 6 Mcal of ME/kg of BW change (27). Partial efficiency of energy utilization for milk Nutrient Composition of the Total production (PE) was calculated according to Mixed Diets the equation of Kronfeld et al. (21), where PE, Nutrient composition of diets is shown in % = [(milk energy)/(ME for milk - energy in Table 1. Au. diets were similar in contents of BW change)] x 100. Retained N was calcu- DM, OM, and Ca. Concentration of CP in the lated by subtracting N in feces, urine, and milk diets ranged from 19.7 to 20.6%. Dietary confrom N intake. Productive N was calculated as centrations of ADF and NDF were about 2 the sum of N retained in the body and N percentage units higher for the control diet secreted in milk. than for the other three diets, probably because soybean hulls in the control diet supplied more ADF and NDF than did WSB included in the Blood Sampling and Analyses other treatments. Contents of gross energy and Samples of blood were obtained by jugular fatty acids increased as additional fat was venipuncture from each cow 3 h after the a.m. added to the diets. The fatty acid compositions feeding on d 21 of each period. Blood was of tallow and WSB are shown in Table 2; mixed immediately with Na-EDTA (.l% final values are. similar to those reported by others concentration), and plasma was collected after (26, 30). centrifugation. Plasma was divided into aliquots and stored at -20'C until analyzed for DMI and Mllk Production and Composition concentrations of glucose (Sigma kit number Dry matter intake was not affected by sup315, Sigma Chemical Co., St. Louis, MO), total cholesterol (Sigma kit number 352), and plemental fat (Table 3). This agrees with data Journal of Dairy Science Vol. 75. No. 7, 1992
FEEDING WHOLE SOYBEANS AND TALLOW
TABLE 2. Patty acid composition of tallow and raw whole Soybeans. Raw whole
Fattv acid
SOVbeans
Tallow
c12:o
1.06 .07 11.30 .03 3.60 21.58 55.40 6.96
.07 320 24.80 5.32 14.50 45.94 5.92 25
c140 C160 C161 C180 C181 C182 c1&3
from other studies in which as much as 5% added tallow or protected tallow (30, 39) or 7.5% added yellow grease (11) were fed to lactating dairy cows. In contrast, DMI were decreased from 1 to 2 kg/d when loo0 g/d of hydrolyzed animal-vegetable (A-V) fat (23) or either 841 or 964 g/d of tallow were fed to lactating dairy cows (7). In the latter trial, the amount of tallow fed to the cows may have been excessive, because they consumed relatively small amounts of feed, and milk production was relatively low. Production of milk was not altered significantly by treatment (Table 3). In previous experiments, animal fats or raw WSB often did not increase milk production when the studies were short-term Latin square or switchback designs or when cows were producing less than 30 kg/d of milk (26, 29, 30, 36, 37). In
1927
other short-term trials, however, tallow (3) or yellow grease (11) inireas4 milk produition. In longer term (18 wk) experiments, milk production was increased by 2 to 3 kg/d when protected tallow (39) or encapsulated tallow (17) was fed to dairy cows. Additional longterm trials with high producing cows in early lactation are needed to determine the magnitude of increase in milk production that can be obtained when animal fats are fed to dairy cows. Milk fat percentage tended to increase (P = .06)when fat was fed to the cows, especially when both tallow and WSB were fed (Table 3). Milk fat yield also tended (P = .06) to increase when cows were fed fat (Table 3). Changes in milk fat percentages have been variable when cows were fed animal fats. Milk fat percentage was increased fiom .3 to .8 percentage units by feeding tallow (3, 7) or yellow grease (6); decreased .4 to .7 percentage units by feeding 5% tallow (39), 7.5% yellow grease (ll), or 5% yellow grease (19); or unchanged by feeding animal fats (17, 23, 30, 37). Adding more than 5% animal fat to the diet, especially the more unsaturated animal fats such as yellow grease or A-V fat, is more likely to depress milk fat percentage than adding either more saturated fat or smaller amounts of fat to the diet. Milk fat percentage and ruminal acetate to propionate ratios were decreased when 5% yellow grease was added to the diet compared with a diet that contained 5% hydrogenated yellow grease (19).
TABLE 3. DMI, milk production, and milk composition for cows fed whole soybeans (WSB) and tallow.
Treatments Control
Item
Control
Control + WSB
DM& W d Milk. kgld % Fat, kgld 4% FCM, kg/d
22.2 30.5 3.34 1.02 27.5 3.14 .96 7.94 2.42
21.8 30.9 3.41 1.05 28.2 3.12 .96 7.86 2.43
CP, %
a,W d SNF, % SNF, kgld
Control
+ WSB + 2.5% tallow
+ WSB + 4.0% tallow
SEM
21.7 30.5 3.56 1.08 28.4 3.13 .95 7.67 2.33
21.4 29.7 3.52 1.05 27.5 3.13 .93 7.81 2.32
.6 .9 .06 .02 .6 .02 .03 .ll .07
kontrol v e m fat sources (P = .MI. *WSB vefsus WSB and tallow '2( = .11). Journal of Dairy Science Vol. 75, No. 7. 1992
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SCHAUPP ET AL.
Yields and percentages of protein and SNF in milk were not changed by treatment (Table 3), which agrees with data from other expeiments in which raw WSB or animal fats were fed to dairy cows (29, 30). In many other trials, however, milk protein percentage was decreased .1 to .2 percentage units by raw WSB (26, 36) or animal fats (6, 7, 10, 11, 17, 19) fed to dairy cows. The contents of casein and whey proteins in milk were decreased, and there was a trend for an increase in the percentage of NPN in milk when 3.5 to 7.5% yellow grease was added to diets of dairy cows (6, 10, 11). The mechanism for the decrease of milk protein percentage that often occurs when fat is fed to dairy cows remains undetermined. Composition of milk fat (weight percentages) and yields of individual fatty acids in milk fat are shown in Tables 4 and 5. Diets containing supplemental fat did not affect the weight percentage (Table 4) or yield (Table 5) of butyric acid in milk fat. Adding fat to the diet decreased the weight percentages and Yields of c 6 0 , c8:0, c 1 0 0 , C12:Os C14:Ov c 1 4 1 , and C15:o fatty acids in milk fat. The weight , C10.0, percentages and yields of C ~ Oc8:0, C12:0, and C140 fatty acids decreased further
when tallow was added to the diets. Addition of dietary fat decreased the weight percentages and yield of c16:O; however, WSB resulted in larger decreases than did the combinations of WSB and tallow. The greater content of C 1 6 0 in tallow than in soy oil may have provided more C160 for incorporation into milk. Fat supplementation to the diet did not affect weight percentages and yields of C1e. and C17:o fatty acids; however, weight percentages and yields of C16. and C17:o fatty acids were increased when cows were fed WSB and tallow when compared with WSB. Weight percentages and yields of c18:O in milk were increased by including supplemental fat in the diet; however, increases were less when tallow was added to the diet, especially at 4% of the diet. Weight percentage and yield of c18:1 in milk were increased dramatically by supplemental fat; the greatest increases occurred when both tallow and WSB were included in the diet. Supplementing fat to the diet did not affect weight percentage or yield of c18:2 in milk, but adding tallow to diets containing WSB decreased weight percentage and yield of c18:2 compared with adding only WSB. Weight percentage and yield of c18:3 in milk
TABLE 4. Least squares means for weight percentages of fatty acids and glycerol in milk fat from cows fed whole soybeans (WSB) and tallow. Treatments
Control
+ WSB
Control + WSB + 2.5% tallow
C182
2.7 2.0 1.5 2.7 3.2 11.2 1.2 .8 27.7 2.1 .7 8.3 21.0 2.0
c183
.8
3.0 1.8 1.2 2.1 2.6 9.5 .9 .7 23.6 1.7 .6 11.4 25.2 2.7 .7 12.2
2.6 1.5 .9 1.4 1.6 8.2 .9 .6 25.4 2.2 .7 11.0 28.3 2.0 .6 11.9
Fatty acid
Control
Significance of difference (P)
Control
+ WSB + 4.0%
Control
tallow
SEM
vs. fat
2.6 1.5 .9 1.3 1.7 7.7 .9 .7 25.9 2.7 .7 10.0 29.3 2.0 .3 11.8
.2 .1 .1
