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Effect of dietary thiamin supplementation on milk production by dairy cowsEffect of Dietary Thiamin Supplementation
on Milk Production by Dairy Cows
R. D. Shaver and M. A. Bal
fiber carbohydrate, PEM = polioencephalomalacia, TH
= thiamin supplemented diet, TLC = theoretical length
We conducted three experiments to determine the effects of dietary thiamin supplementation on milk pro-duction by dairy cows. In trial 1, 28 Holstein cows were INTRODUCTION
blocked by parity and assigned randomly to either pla-cebo or thiamin top-dress for the 8-wk experiment to Most of the study of thiamin for ruminants has been provide a supplemental thiamin intake of 0 or 150 mg/d in relation to a clinical central nervous system condition per cow. Within each of these groups, cows were further observed in beef cattle called polioencephalomalacia assigned randomly to two total mixed rations (TMR) (PEM). Cattle with clinical signs of PEM, which include
for 4 wk, with the TMR treatments then reversed for circling behavior, rigid stance, and convulsions, re- a second 4-wk experimental period. Milk yield was 2.7 spond dramatically to large intravenous doses of thia- kg/d higher for thiamin-supplemented cows. Yields of min (3, 6). Incidence of PEM appears to be related to milk fat and protein were increased 0.13 and 0.10 kg/ ruminal destruction of thiamin by thiaminase enzymes d, respectively, by dietary thiamin supplementation. In produced by ruminal bacteria (3, 6). Cattle fed high trial 2, 20 multiparous Holstein cows were used in a concentrate or feedlot diets are most susceptible to crossover design with 4-wk periods. Placebo or thiamin PEM, but it has also been observed in grazing animals premixes were added to TMR to provide an approximate daily supplemental thiamin intake of 0 or 300 mg/cow.
In lactating dairy cows, we are unaware of any re- Milk and protein yields tended to be 0.7 and 0.04 kg/d ports of PEM or performance response to dietary thia- higher, respectively, for thiamin-supplemented cows.
min supplementation. Without extensive ruminal thia- In trial 3, 16 multiparous Holstein cows were used in min destruction, a thiamin deficiency in lactating dairy a replicated 4 × 4 Latin square with 21-d periods. Pla- cows seems unlikely, since Erdman (7) estimated a cebo or thiamin premixes were added to TMR to provide fivefold higher small intestinal flow of thiamin (ruminal an approximate daily supplemental thiamin intake of escape + production) relative to requirements extrapo- 0 or 300 mg/cow. Dry matter intake tended to be 0.8 lated with data from lactating sows. Some practical kg/d lower for thiamin-supplemented cows. Milk fat feeding guides recommend dietary thiamin supplemen- percentage tended to be 0.18 percentage units lower and tation when high levels of corn gluten feed are used in fat yield was 0.08 kg/d lower for thiamin-supplemented cows. Thiamin supplementation tended to increase The main objective of our first trial was to evaluate milk and component production when dietary concen- intake and milk production by dairy cows being fed a trations of neutral and acid detergent fiber were lower corn byproduct-based diet (CBP) versus a corn-soybean
and nonfiber carbohydrate was higher than recom- meal-based diet (CS). Because a corn byproduct-based
on corn gluten feed was under evaluation in trial 1, a (Key words: thiamin, milk production, intake)
secondary objective was to evaluate the effect of dietarythiamin supplementation on lactation performance.
Abbreviation key: C = control diet, CBP = corn by-
Based on the results of trial 1, our objective in trials 2 product diet, CS = corn-soybean meal diet, NFC = non-
and 3 was to further evaluate the effect of dietary thia-min supplementation on intake and milk production bydairy cows. Corn silage was the main forage used intrial 2, because it was available after a forage feeding trial conducted by our laboratory. Alfalfa silage was the Accepted April 20, 2000.
Corresponding author: R. D. Shaver; e-mail: rdshaver@facstaff.
sole forage used in trial 3, because our main objective was to evaluate the effect of processing alfalfa silage on intake, digestion, and milk production by dairy cows.
(Arthur H. Thomas, Philadelphia, PA). Samples were Although there is no proposed relationship between analyzed for DM, OM, and CP (1), NDF using α-amylase these factors, dietary thiamin supplementation was in- (Sigma no. A3306; Sigma Chemical Co., St. Louis, MO) cluded in the factorial design used in trial 3 to gain and sodium sulfite (15), and ADF (8). Nonfiber carbohy- more data on its effects. Only effects related to dietary drate (NFC) content was calculated as the difference
thiamin supplementation are presented and discussed between 100 and the sum of (NDF + CP + ash + fat) with NDF, CP, and ash determined analytically andfat with NRC (11) tabular values.
MATERIALS AND METHODS
Cows were milked twice daily and production was recorded at each milking during the preliminary and experimental periods. Milk samples taken from a.m.
Twenty-eight Holstein cows (16 multiparous and 12 and p.m. milkings on d 20 and 21 and d 27 and 28 of each primiparous) averaging 142 DIM (SD = 41) and 605 kg period were analyzed for fat, CP, and urea-nitrogen by of BW (SD = 82) at trial initiation were blocked by parity infrared analysis (Ag Source Milk Analysis Laboratory, and assigned randomly to either placebo or thiamin Menomonie, WI). Milk composition was calculated as top-dress for the 8-wk experiment. Within each of these an average of a.m. and p.m. samples with the proportion groups, cows were further assigned randomly to TMR of daily milk production at that milking as a containing either CS or CBP for 4 wk with the TMR treatments then reversed for a second 4-wk experimen- Data from wk 3 and 4 and wk 7 and 8 of the experi- tal period. Before the start of the experiment, all cows ment were analyzed as a split-plot design using the were fed diet CS during a 2-wk preliminary period.
general linear models procedure of SAS (13). Milk pro- Cows were housed and fed individually in tie stalls.
duction data from the second week of the preliminary The top-dress—composed of either wheat middlings or period were used as a covariate. The model included a thiamin mononitrate—wheat middlings mixture was covariate, parity (primiparous vs. multiparous cows), fed at the rate of 57 g/d per cow to individual cows once diet (CS vs. CBP), top-dress (C vs. TH), cow, and two- daily to provide a supplemental thiamin intake of 0 (C)
way interaction terms. Cow effects were used as the or 150 (TH) mg/d per cow.
error term for testing top-dress effects and residual The ingredient composition of CS and CBP diets is error was used to test diet and top-dress by diet inter- presented in Table 1. Both diets contained 55% alfalfa silage and 45% concentrate (DM basis). Corn byproductwas included in the CBP diet as replacement for two- thirds of the ground, shelled corn found in the CS diet.
The dried, pelleted corn byproduct (Koch Feed Prod- Twenty multiparous Holstein cows averaging 195 ucts, Wichita, KS) was composed of wet corn gluten DIM (SD = 33) and 657 kg of BW (SD = 52) at trial feed and starch sludge, starch, and syrup. Starch sludge initiation were used in a crossover design with 4-wk is composed of the settlings from starch cookers used periods. Wheat middlings or thiamin mononitrate- in the production of corn syrup. The higher CP content wheat middlings mixture were added to TMR to provide of corn byproduct than shelled corn allowed for elimina- an approximate daily supplemental thiamin intake of tion of soybean meal from the CBP diet and dictated that diet CS also be formulated for 20% CP (DM basis).
Dietary ingredient composition is presented in Table Diets were formulated to meet or exceed NRC (11) re- 1. Diets contained 50% forage (two-thirds corn silage quirements for minerals and vitamins and were fed as and one-third alfalfa silage) and 50% concentrate (DM TMR once daily. All cows were injected with bST (Posi- basis). Placebo or thiamin supplements were added to lac, Monsanto Company, St. Louis, MO) every 14 d respective TMR at 0.5% of DM. Diets were formulated for 17.5% CP (DM basis) and to meet or exceed NRC (11) Dry matter content of alfalfa silage was determined requirements for minerals and vitamins. Diets were fed weekly with a 60°C forced-air oven to adjust as-fed as TMR once daily. All cows were injected with Posilac ratios of diet ingredients. The amounts of TMR offered every 14 d starting on d 1 of the experiment.
and refused were recorded daily during the experimen- Dry matter content of corn silage and alfalfa silage tal period. The alfalfa silage and concentrate mixtures was determined weekly with 60°C forced-air oven for were sampled on d 15 and 22 of each period and each adjustment of as-fed ratios of dietary ingredients. Cows was composited by period for nutrient analysis. Com- were housed and fed individually in tie stalls. The posite feed samples were dried for 48 h in a 60°C forced- amounts of TMR offered and refused were recorded air oven and ground to pass a 1-mm Wiley mill screen daily. The corn silage, alfalfa silage, and concentrate Journal of Dairy Science Vol. 83, No. 10, 2000 Table 1. Diet ingredient and nutrient composition for trials 1, 2, and 3.
1CS = Corn-soybean meal diet.
2CBP = Corn byproduct diet.
3C = Control diet.
4TH = Thiamin-supplemented diet.
5Trial 1: Contained 22.8% CP, 36.8% NDF, and 28.4% ADF (DM basis). Trial 2: Contained 25.2% CP, 36.7% NDF, and 32.9% ADF (DM basis). Trial 3: Contained 20.3% CP, 44.1% NDF, and 32.8% ADF (DMbasis).
6Contained 35.6% DM and 7.3% CP, 40.6% NDF, and 23.9% ADF (DM basis).
7Contained 88% DM and 21.4% CP, 25.6% NDF, 13.6% ADF, and 3.4% ether extract (DM basis).
8SoyPlus, West Central Cooperative, Ralston, IA.
9Trace-mineralized salt: NaCl, 92.5 to 95.5%; not less than 0.55% Zn, 0.55% Mn, 0.35% Fe, 0.14% Cu, 10Vitamin supplement was added to provide vitamins A, D, and E at the rate of 150,000, 50,000, and 500 11Trial 1: Wheat middlings or thiamin mononitrate-wheat middlings mixture top-dressed at the rate of 57 g/d per cow to individual cows once daily to provide 0 or 150 mg of thiamin/d per cow. Trials 2 and 3:Wheat middlings or thiamin mononitrate-wheat middlings mixture added to TMR to provide an approximatedaily thiamin intake of 0 or 300 mg/cow.
12NFC = Nonfiber carbohydrate = 100 − (NDF + CP + ether extract + ash).
mixture were sampled on d 15 and 22 of each period and design using the general linear models procedure of each was composited by period for nutrient analysis.
Composite feed samples were dried for 48 h in a 60°Cforced-air oven and ground to pass a 1-mm Wiley mill screen (Arthur H. Thomas, Philadelphia, PA). Sampleswere analyzed for DM, OM, CP, NDF, and ADF, and Sixteen multiparous Holstein cows (eight ruminally NFC was calculated as described for trial 1.
cannulated and eight intact) averaging 120 DIM (SD = Cows were milked twice daily, and production was 36) and 600 kg of BW (SD = 39) at trial initiation were recorded at each milking. Milk samples taken from a.m.
used in a replicated 4 × 4 Latin square design with 21- and p.m. milkings on d 20 and 21 and d 27 and 28 of each d periods, 14 d for dietary adaptation. Thiamin supple- period were analyzed for fat, CP, and urea-nitrogen by mentation and alfalfa silage processing were main ef- infrared analysis (Ag Source Milk Analysis Laboratory, fects in the 2 × 2 factorial arrangement of treatments.
Wheat middlings or thiamin mononitrate-wheat mid- Dry matter intake and milk production data from wk dlings mixture were added to TMR to provide an ap- 3 and 4 and wk 7 and 8 were analyzed as a crossover proximate daily supplemental thiamin intake of 0 or Journal of Dairy Science Vol. 83, No. 10, 2000 300 mg/cow. Alfalfa silage was either harvested at 0.95 bags were washed in a commercial washing machine cm theoretical length of cut (TLC) without rolling or
with cold water for two cycles of 12 min each (4). Bags 1.90 cm TLC with a 1-mm roll clearance with an experi- and residue were then dried at 60°C for 48 h to deter- mental pull-type chopper fitted with an on-board Data from wk 3 of each period were analyzed as a Dietary ingredient composition is presented in Table replicated Latin square using the general linear models 1. Diets contained 60% alfalfa silage and 40% concen- procedure of SAS (13). Ruminal pH data were analyzed trate (DM basis). Placebo or thiamin supplements were using PROC MIXED of SAS (10) for repeated measures.
added to respective TMR at 0.5% of DM. Diets wereformulated for 18.5% CP (DM basis) and to meet or RESULTS AND DISCUSSION
exceed NRC (11) requirements for minerals and vita-mins. Diets were fed as TMR once daily. All cows were Dietary nutrient composition and DMI and milk pro- injected with Posilac every 10 d starting on d 1 of the ex- duction data from the three experiments are presented Dry matter content of alfalfa silage was determined weekly with a 60°C forced-air oven for adjustment of as-fed ratios of diet ingredients. Cows were housed and Diets contained 19.4 to 20.7% CP, which exceeds NRC fed individually in tie stalls. The amounts of feed offered (11) guidelines. This was related to the high CP content and refused were recorded daily. The alfalfa silage of the alfalfa silage and its dietary inclusion rate and treatments and concentrate mixtures were sampled on the higher CP content of corn byproduct and its dietary d 15 of each period for nutrient analysis. Feed samples substitution rate for ground, shelled corn. Although not were dried for 48 h in a 60°C forced-air oven and ground measured, high ruminal degradability of dietary CP to pass a 1-mm Wiley mill screen (Arthur H. Thomas, was likely because high CP degradability has been re- Philadelphia, PA). Samples were analyzed for DM, OM, ported for alfalfa silage, solvent-extracted soybean CP, NDF, and ADF, and NFC was calculated as de- meal, and corn gluten feed (14). The concentration of dietary NDF (27.4% of DM on average) was above the Cows were milked twice daily and production was NRC (11) minimum recommended allowance. However, recorded at each milking. Milk samples taken from a.m.
the concentration of NDF in diet CS was slightly below and p.m. milkings on d 17, 18, and 19 of each period the NRC (11) minimum recommended allowance, and were analyzed for fat, CP, and urea-nitrogen by infrared diet CS contained 5.6 percentage units less NDF than analysis (Ag Source Milk Analysis Laboratory, Meno- diet CBP. This was related to the higher NDF content of corn byproduct and its substitution rate for corn grain.
Ruminal fluid from the eight ruminally cannulated Concentration of dietary NFC (41.5% of DM on average) cows was sampled immediately before feeding and at was slightly above the optimum concentration of 40% 4, 8, and 12 h postfeeding on d 19 and 20 of each period.
(DM basis) suggested by Nocek and Russell (12), but Samples were taken from five different locations in the diet CS contained 6.5 percentage units more NFC than rumen via the cannula using a custom-made metal filter probe and pH was determined (Twin pH meter Model Milk yield was 2.7 kg/d (P = 0.01) higher for cows fed B-213, Spectrum Technologies, Inc., Plainfield, IL).
TH. Milk fat and protein percentages were unaffected The 48-h ruminal in situ DM degradation of the al- by dietary thiamin supplementation, but yields of fat falfa silage treatments was determined in ruminally and protein were increased 0.13 and 0.10 kg/d (P = cannulated cows on d 19 of each period. In situ bags 0.01), respectively, for TH. Grigat and Mathison (9) (25 × 35 cm, 52-µ pore size) were made of Dacron polyes- reported that dietary thiamin supplementation in- ter cloth (R102 Marvelaire White, N. Erlanger, Blum- creased average daily gain in feedlot steers fed all-con- gardt and Co., Inc., New York). The alfalfa silage treat- centrate diets. Positive effects of dietary thiamin sup- ments were incubated with triplicate bags per cow and plementation on milk and component yields were evi- matching incubation alfalfa silage with diet alfalfa si- dent on both CS and CBP diets, and no thiamin lage by cow and period. Twenty-five grams of DM was supplementation × diet interaction was observed. This weighed into each bag (30 mg/cm2 sample size to surface suggests that effects of dietary thiamin supplementa- area ratio) and incubated without drying or grinding tion observed in this trial were unrelated to the use of at 2 h postfeeding. In situ bags were placed in a nylon corn byproduct vs. corn grain plus soybean meal. This laundry bag and positioned in the ventral rumen. Dupli- finding contradicts Berger et al. (2) who recommended cate blank bags were incubated in each laundry bag to dietary thiamin supplementation only when feeding correct for influx of DM into the sample bags. In situ Journal of Dairy Science Vol. 83, No. 10, 2000 Table 2. Effect of dietary thiamin supplementation on DMI, milk production, and milk composition by dairy cows in trials 1, 2, and 3.
1Means are covariate-adjusted least square means.
2C = Control diet.
3TH = Thiamin-supplemented diet.
4NS = Not significant (P > 0.15).
was unaffected by dietary thiamin supplementationand there were no treatment × sampling time interac- The concentrations of dietary NDF and ADF were tions; pH averaged 6.49 for C versus 6.52 for TH and below the NRC (11) minimum recommended allowance.
6.26 for C versus 6.27 for TH at 4 h and 8 h postfeeding, The concentration of dietary NFC (46.7% of DM) was respectively (data not presented in table). In situ DM well above the optimum concentration of 40% (DM ba- degradation of alfalfa silage was also unaffected by di- sis) suggested by Nocek and Russell (12). Dietary CP etary thiamin supplementation, averaging 68.8% and concentration (17.0% of DM) was lower than for trial 1 69.0% for C and TH, respectively (data not presented (20.1% of DM on average). Although not measured in either trial, lower ruminal degradability of dietary CPfor this trial versus trial 1 was likely because of the useof corn silage and expeller-extracted soybean meal (14).
Milk and protein yields tended to be 0.7 (P = 0.15) Supplementing dietary thiamin at the rate of 150 to and 0.04 kg/d (P = 0.09) higher, respectively, for cows 300 mg/d per cow increased or tended to increase milk fed TH. Dietary thiamin supplementation did not affect and component production in trials 1 and 2, respec- tively. In trial 1, increased milk, fat, and protein yieldsin response to dietary thiamin supplementation were observed in cows fed TMR containing either corn-by- Dietary concentrations of NDF (32.3% vs. 24.3 to product or corn-soybean meal-based concentrates. Dif- 30.2% of DM) and ADF (22.2% vs. 15.6 to 18.3% of DM) ferences in response to dietary thiamin supplementa- were higher and NFC (36.0% vs. 38.3 to 46.7% of DM) tion between trials cannot be clearly explained, but was lower for this trial than for trials 1 and 2. Also, diets fed in trials 1 and 2 contained lower concentra- dietary NDF from forage was higher for this trial than tions of NDF from forage and total NDF and higher for trials 1 and 2 (26.5% vs. 19.7 to 20.2% of DM). The concentrations of NFC than the diet fed in trial 3. Also, concentration of CP in the diet for this trial (18.7% of the CP concentration of diets fed in trial 1 greatly ex- DM) was intermediate between diets for trials 1 (20.1% ceeded NRC (11) guidelines and of diets fed in trials 2 of DM on average) and 2 (17.0% of DM).
and 3. These differences in dietary nutrient concentra- Intakes of DM tended to be 0.8 kg/d lower (P = 0.15) tions between trials may have influenced ruminal thia- for cows fed TH. Milk fat percentage tended to be 0.18 minase production by rumen bacteria and hence the percentage units lower (P = 0.06) and fat yield was 0.08 observed response to dietary thiamin supplementation kg/d lower (P = 0.05) for cows fed TH. Dietary thiamin (3, 6). Another possible explanation for the observed supplementation did not affect milk yield or protein in variation in response to dietary thiamin supplementa- this trial. No interactions of thiamin supplementation tion between trials could be the presence or nonpres- by alfalfa silage processing were observed.
ence of an antithiamin factor produced by Fusarium Ruminal fluid was sampled as part of our evaluation molds (5). However, we collected no thiaminase or myco- of alfalfa silage processing effects on digestion. Thus, toxin data in these trials to support or refute either ruminal data were also collected regarding the effects explanation. It is unlikely that response differences of dietary thiamin supplementation. Ruminal fluid pH among trials were related to problems with thiamin Journal of Dairy Science Vol. 83, No. 10, 2000 stability, because the expected loss of potency is only 2 Berger, L. L., J. C. Weigel, and S. C. Bidner. 1986. Corn gluten feed for beef cattle. Pages 4–5 in Corn Gluten Feed-The Future 5% over 8- to 12-wk of storage after mixing in a premix of Feeding. Illinois Corn Growers Assoc. Bloomington, IL.
and negligible over 24 h after mixing in TMR (M. B.
3 Brent, B. E., and E. E. Bartley. 1984. Thiamin and niacin in the Coelho, BASF Corp., Mount Olive, NJ, personal commu- 4 Cherney, D.J.R., J. A. Patterson, and R. P. Lemenager. 1990.
nication). The trend for reduced DMI and milk fat in Influence of in situ bag rinsing technique on determination of dry response to dietary thiamin supplementation noted in matter disappearance. J. Dairy Sci. 73:391–397.
5 DiNicola, N. L. 1995. Evidence for an unidentified autoclave-labile trial 3 was unexpected, and we offer no explanation anti-thiamin factor produced by Fusarium proliferatum cultures for this observation. Results of these trials suggest a associated with spiking mortality syndrome. Ph.D. Thesis, Univ.
possible role for thiamin supplementation when dietary 6 Edwin, E. E., and R. Jackman. 1982. Ruminant thiamine require- concentrations of NDF and ADF are lower and NFC is ment in perspective. Vet. Res. Comm. 5:237–250.
higher than recommended. More research with lactat- 7 Erdman, R. A. 1992. Vitamins. Pages 297–308 in Large Dairy Herd Management. H. H. Van Horn and C. J. Wilcox, ed. Am.
ing dairy cows on the response to dietary thiamin sup- plementation and on nutritional factors affecting this 8 Goering, H. K., and P. J. Van Soest. 1970. Forage Fiber Analyses.
(Apparatus, Reagents, Procedures, and Some Applications).
Agric. Handbook No. 379. ARS-USDA, Washington, DC.
9 Grigat, G. A., and G. W. Mathison. 1982. Thiamin supplementa- tion of an all-concentrate diet for feedlot steers. Can. J. Anim.
10 Littell, R. C., G. A. Milliken, W. W. Stroup, and R. D. Wolfinger.
Appreciation is extended to Sandra Trower and Rob- 1996. SAS System for Mixed Models. SAS Inst., Inc., Cary, NC.
11 National Research Council. 1989. Nutrient Requirements of Dairy ert Elderbrook at the University of Wisconsin Arlington Cattle. 6th rev. ed. Natl. Acad. Sci., Washington, DC.
and Madison Dairy Cattle Centers, respectively, for the 12 Nocek, J. E., and J. B. Russell. 1988. Protein and energy as an care and feeding of the cows. The technical assistance integrated system. Relationship of ruminal protein and carbohy-drate availability to microbial synthesis and milk production. J.
in the laboratory of Sandra Bertics and Erin Miller is 13 SAS User’s Guide: Statistics. Release 6.03 Edition. 1988. SAS 14 Satter, L. D. 1986. Protein supply from undegraded dietary pro- REFERENCES
15 Van Soest, P. J., J. B. Robertson, and B. A. Lewis. 1991. Methods of dietary fiber, neutral detergent fiber, and nonstarch polysac- 1 Association of Official Analytical Chemists. 1990. Official Methods charides in relation to animal nutrition. J. Dairy Sci. 74:3583– of Analysis. Vol. I. 15th ed. AOAC, Arlington, VA.
Journal of Dairy Science Vol. 83, No. 10, 2000
Second Announcement IFFS 2007: April 29 – May 03, 2007 International Federation of Fertility Societies XIX World Congress on Fertility & Sterility Section 7 Scientific Programme Trilogies Key to the structure of the programme wil be 19 trilogies. Some wil run concurrently so that delegates wil be able to select sessions of greatest interest to them. These are topic sp