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Extension Section
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J O U R N A L OF D A I R Y S C I E N C E
concentrations of blood urea nitrogen or blood ammonia; but a more rapid increase in blood urea nitrogen after feeding was observed for the UA than the other treatments. The data strongly suggests that intake depression observed on high-urea diets is due to the undesirable taste of urea and not ruminal or postruminal effects. P182. Urea-treated corn silage in low protein rations for lactating cows. J. T. Huber* and J. W. Thomas, Michigan State University, East Lansing. Corn silages (34 to 37% dry matter) onstied with: 1) no additive; 2) 0.5% urea; 3) 0.75% urea; and 4) 0.75% urea -~ 0.17% CaSO, were fed as the only forage to 60 heavily lactating cows (10/group) for 70 days. Concentrates containing 8, 12, or 18% CP were also fed at 1 kg/3 kg milk. Treatments, designated by silage number and per cent CP in concentrate, were: Group A 1, 8; Group B 1, 18; Group C 2, 8; Group D 2, 12; Group E 3, 8, and Group F 4, 8. Nitrogen balances were determined on 5 cows/group at the end of the feeding period. Milk yields (kg/day) and persistencies (%) for the respective treatments averaged 19.2, 67; 25.7, 88; 23.7, 81; 26.4, 91; 23.8, 82; 23.9, 84. Group A was lower (P<0.05) than all others, with Group C and E lower (P~0.05) than D. Total dry matter and silage dry matter intakes (kg/100 kg body weight) averaged, respectively, 2.4, 1.2; 2.8, 1.6; 2.7, 1.4; 3.0, 1.6; 2.7, 1.5; 2.8, 1.5. Silage intake of Group A was lower (P~0.05) than Groups B and D. Balance data showed the negative Controls A excreted 142% of their digested nitrogen as milk and urine, while other groups averaged 89 to 109%.
P183. Lactation comparisons of alfalfa meal and urea as the nitrogen supplement. H. R. Conrad*, J. W. Hibbs, and V. A. Neuhardt, Ohio Agricultural Research and Development Center, Wooster. Sixty-six per cent alfalfa meal, 31.6% urea, 2.0% dicalcium phosphate, and 0.4% sodium propionate were mixed and pelleted for ira-
EXTENSION E l . N e w developments in production testing. F. N. Dickinson, Animal Husbandry Research Division, USDA, Beltsville, Maryland. A technical subcommittee of the National DHIA Coordinating Group has been formed to coordinate research on testing plans and methods for estimating yield. The committee decided that major problems facing it were estimation of milk and milk fat yield under alternate AM-PM sampling plans; adjustment of lactation milk and milk fat yields at start and J. DAIRY SOII~C~ VOL. 52, NO. S
proving the edibility of urea containing feeds while sustaining maximum tureen synthesis. This supplement (Dehy-100) contained 16% nitrogen. When 10% of Dehy-100 was added to grain concentrate, crude protein content was raised to 18%. In a switchback experiment comparing Dehy-100 with soybean meal in isonitrogenous diets, ten Holstein cows fed Dehy-100 produced an average of 7,933 kg of milk, 280 kg of fat, and 7,357 +---805 kg of 4% fat-corrected milk; consumed 3,873 -----481kg of digestible dry matter; and used 32% of the intake nitrogen for milk. The values for soybean meal feeding were 7,946 -+- 267, 7,182 ~927 and 3,614 ± 409 kg, and 33%, respectively. The maintenance of high productivity in cows fed Dehy-100 demonstrated its usefulness as a substitute for vegetable protein. P184. Dietary protein levels for milking cows. J. W. Thomas, Michigan State University, East Lansing. A corn silage-alfalfa hay-concentrate ration containing 10 to 11 or 13% protein was fed to 22 cows beginning 45 days postpartum and continued for two lactations. Milk:grain ratio was 2:1. From 45 to 305 days postpartum cows fed 10 to 11% protein produced 2.0 kg milk/cow/day less than projected and those fed 13% produced 3.4 kg more. Compared to their previous lactation, eight cows fed 10 to 11% protein produced 1.3 kg less and six cows fed 13% produced 5.4 kg more per cow per day. During the second lactation eight cows fed 10 to 11% protein averaged 6,562 (range, 3,900 to 9,581) kg milk and six fed 13% protein 7,851 (range, 6,257 to 9,266) kg or ]02 and 95% of their first experimental lactation. Monthly persistency for first lactation was 90 versus 94% and for second lactation 93 versus 95% respectively. In a 90day trial 16 cows at 180 days postpartum were fed the 10 or 13% rations. Fat-corrected milk production was ]7.6 versus 17.0 kg/cow/day for those fed 10 and 13% respectively. After mid-lactation a ration of 10% protein is adequate but for the entire lactation some cows require a higher level of dietary protein.
SECTION
end of lactation under TIM ; parameters of daily milk fat variation; definition of acceptable tolerances for errors in estimates of yield, and; modifications to standard DHI rules to make them compatible with TIM. The last problem is the only one that has been mostly resolved. Progress has been made towards solving the other problems for lactation milk yield. Little progress has been made on any of the problems of milk fat yield or the errors found in, or acceptable tolerances for,
ASSOCIATION AFFAIRS
periodic milk weights. D a t a are available for studies on milk. Data must be collected for studies on milk fat. F a r greater resources than are presently available to this committee must be devoted to the timely solution of these problems. E2. Alternate AM-PM testing for Dairy Herd Improvement Association programs--operational procedures. D. N. P u t n a m ~ and H. C. Gilmore, The Pennsylvania State University, University Park. I n slightly less than four months from the time the a~ternate A~-P~ plan of testing was approved by the Pennsylvania Directors as an optional program, nearly 800 dairymen in 40 of Pennsylvania's 67 counties changed from the conventional twice-daily weighing and sampling on test day to the alternate A~-P~ plan. More than 75% of these herds were enrolled on official D H I test. Some counties adjusted fee schedules to provide a price differential for alternate AM-P~ testing, others did not. Generally the alternate plan fees are about 80% as much as the charges for the conventional program. The single milk weight is recorded on the barn sheet and doubled by data processing. The supervisor records whether milking is AI~ or P1/i which is printed on the dairymen's report. Lactation records are reported to USDA as unofficial records but by action of the state D t I I A directors lactation and herd records can be used for county and statewide publicity when properly labeled. E3. Thyroprotein feeding--research findings and application in dairy herd management. J. W. Thomas, Michigan State University, E a s t Lansing. Giving extra thyroid hormone temporarily increases milk production and this effect is more prolonged if additional feed is also .given. Fat-corrected milk increase ( k g / d a y ) is nonsignificantly related to days in milk (X1), age in months (X2) and production level (X3) when thyroxine treatment is initiated. Fat-corrected milk increase ( l b / d a y over 60 days) ---- 1.3 + 0.01 X 1 + 0.012 X2 -0.01 X 3. F a t test m a y also be increased but it is not sufficiently related to any factor that can be used to estimate response. Cvenerally, the largest increase in test and largest fatcorrected milk increase on a percentage basis occurred in cows having the smaller milk yield. There is an extremely large variation in response among cows within a herd and between herds. Cows that respond the most also have the largest decrease when thyroxine is discontinued. Over an entire lactation no measurable differences in production are likely to be found due to thyroprotein feeding. Reproductive performance and health of cows is not notably altered although temperature, respiration and heart rates are increased.
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E4. Genetic evaluations in action. B. R. Eastwood*, D. E. Voelker, and A. E. Freeman, Iowa State University, Ames. A selection index for t r a n s m i t t i n g ability was applied to milk and f a t records of more than 300,000 cows in 6,290 herds in eight states which have records processed at Iowa State University. A total of 1,076,221 lactations, including those in progress 45 days or more, was used in the calculations. Deviations of 305-2 time-mature equivalent lactations from herdmates (within breed, herd, and year-season) of the cow, paternal s~sters, dam, daughters, and maternal sisters were used in calculating the estimated average transmitting ability of each cow. Dairymen were provided within-herd rankings of their cows and a comparison of sire averages, selection differentials for estimated average transmitting ability, and other management criteria with state breed averages. Sixty-two educational meetings were conducted with Iowa dairymen during early 1969, emphasizing genetic evaluation of the herd and the application of the cow's estimated average t r a n s m i t t i n g ability and s i r e ' s - P r e dicted Difference in evaluating potential matings and offspring. B5. Bffect of genetic t r e n d on first summary of artificial insemination sampled sires and succeeding summaries. H. W. Carter, Cornell University, Ithaca, New York. Records of 14,500 daughters of 19 young sires, randomly sampled in artificial insemination, and returned to service as a result of the production of their first daughters, were studied to determine the effect of genetic trend on the level of their second crop of daughters. These 19 sires were selected from a total group of 80 sampled. The average superiority over herdmates of the first crop of daughters was plus 125 kg of milk. F i v e years later, these selected sires had a second crop of daughters. Their average superiority over herdmates was plus 7 kg of milk. This is a decrease of 118 kg of milk which is an average drop of 24 kg a year. The correlation of the second summary to the first summary was .8166, indicating a good degree of accuracy for the first selection which was based on a limited number of daughters. The average number of daughters p e r sire in the first summary was 69 and in the second 694. E6. Relation between initial and later United States Department of Agriculture--Dairy Herd Improvement Association sire summaries. B. T. McDaniel* and F. 1~. Dickinson, Animal H u s b a n d r y Research Division, USDA, Beltsville, Maryland. Predicted Differences (PD) from USDAD t t I A Sire Summaries of A p r i l 1967 and based on 50 progeny or less were defined as the initial summary (X) in all cases. IndeJ . DAIRY SCIEI~CE Vor.. 52, NO. 6
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pendent l a t e r summaries (Y) were computed by subtracting the initial from the latest. Comparisons were made only where the reliability of Y was ~ X. Analysis I contained 51 bulls with X based on non-artificial insemination (AI) progeny only (avg repeatability, ---- .38). Analysis I I contained 47 bulls with X based on A I progeny only (R = .52). All later summaries were based on A I progeny only. Correlations between X and Y for PD for milk yield were 0.67 versus an expected r of 0.52 in I, and 0.71 versus an r of 0.61 in II. Regressions of Y on X for PD (milk) were ] . 0 9 ± 0 . 1 7 in I and 0 . 9 0 - . 0 . 1 3 in II. F o r f a t yield, r's were 0.69 and 0.64, and b's were 0.98 ± 0.15 and 0.88 ± 0.16, respectively. F o r f a t percentage (deviation from herdmates), r's were 0.76 and 0.80, and b's were 0.55 ± .07 and 0.76 -* .09. Bias in PD (milk) was 51 kg in I versus --16 kg in I L The initial PD was the best predictor of each measure of breeding value for milk and f a t studied in the later summary. E7. Selection differentials of sires of bulls used in Dairy Herd Improvement Association herds. R. H. Miller ~, B. T. McDaniel, F. 51. Dickinson, and V. H. Lytton, Animal Husbandry Research Division, USDA, Beltsville, Maryland. All sire-son pairs with Predicted Difference (PD) data available as of September 1967 were studied to assess the amount of s.election practiced in choosing bulls for service. The numbers of sire-son pairs were as follows: Ayrshire, 684; Guernsey, 3,519; Holstein, 11,372; Jersey, 2,590; and Brown Swiss, 555. The sire's proof was repeated for each of his sons to obtain selection differentials weighted by the number of offspring. The mean weighted selection differentials for PD milk were as follows: Ayrshire, --46 kg; Guernsey, --12 kg; Holstein, --30 kg; Jersey, + 1 3 kg; and Brown Swiss, --14 kg. Selection differentials for f a t per cent were uniformly positive, ranging from .03% to .05%. The 15 Holstein sires with PD's for milk above 453.6 kg had a total of 176 sons whose PD's for milk averaged 82.6 kg. Only 39.5% of the Holstein bulls with summarized sons had PD's for milk yield above breed average. E8. Relative selection differentials of sires of artificial insemination ( A I ) bulls for production traits. 1T. H. Lytton*, R. H. Miller, B. T. McDaniel, and F. 51. Dickinson, Animal H u s b a n d r y Research Division, USDA, Beltsville, Maryland. All pairs of sires and their A I sons with Predicted Difference (PD) data available as of September 1967 were utilized to determine the degree of selection practiced in choosing bulls for use in AI. The numbers of sire-AI son pairs were 1.09 Ayrshire, 628 'Guernsey, J. DAIRY SCIENCE VOL. 52, NO. 6
1,503 Holstein~ 447 Jersey, and 164 Brown Swiss. The sire's evaluation was repeated for each of his sons to obtain relative selection differentials weighted by the number of sons. The mean weighted selection differentials for A I bulls for PD milk ranged from --42 to 55 kg among the breeds. Mean PD's of the sons ranged from --20 to 5 kg. Selection differentials were generally positive for f a t yield (0 to 2 kg), and p e r cent f a t (--0.01 to .10%). The apparent superiority for PD milk yield of the sires of A I bulls over the sires of non-AI bulls ranged from 5 kg to 50 kg for the five breeds. Superiority for PD fat ranged from 1 to 2 kg, and for f a t per cent from 0.00 to 0.03%. F u t u r e A I bulls can and should possess a much higher selection differential for yield traits. E9. ]~stimates of sire-son relationships for yield traits in the five major dairy breeds. F. 5I. Dickinson*, B. T. McDaniel, R. H. Miller, and V. H. Lytton, Animal HusbandiT. Research Division, USDA, Beltsville, Maryland. The number of sire-son pairs for the five major d a i r y breeds were: Ayrshire, 684; Guernsey, 3,505; Holstein, 10,828; Jersey, 2,590; Brown Swiss, 555. Gross correlations between Predicted Differences (PD) for milk were 0.22, 0.25, 0.28, 0.33, and 0.14 for the five breeds respectively. F o r PD f a t r's were 0.23, 0.28, 0.26, 0.28, and 0.16. F o r f a t per cent (deviation from herdmates) r's were 0.24, 9.29, 0.30, 0.30, and 0.31. Gross regressions of PD-son on PD-sire were for milk, 0.14 ± .02, 0.18 ± .01, 0.19 ±.01, 0.23 ± . 0 1 , and 0.]3 ± . 0 4 ; for fat, 0.14 + .02, 0.18-* .01, 0.18 ± .01, 0.19 ± .01, and 0.15 -* .04; and for f a t per cent (deviation), 0.31 -*.05, 0.33 *- .02, 0.37 -* .01, 0.35 -* .02 and 0.38 -* .05. Sire-son correlations of PD's were higher than those based on unadjusted devia£ions from herdmates by 0.02 to 0.06 in all breeds except Brown Swiss. Correlations of sire-son PD's in Holsteins increased as r e p e a t a b i l i t y level of both sire and son increased. Even at the lowest repeatability categories the sire's PD was a useful predictor of the son's PD. El0. Progress report concerning a code of ethics for use of Dairy Herd Improvement Program results. D. E. Voelker, Iowa State University, Ames. During the p a s t two years, a special committee under the Coordinating Group of the National Cooperative Dairy H e r d Improvement Program has developed a code of ethics on the availability and use of d a i r y production records. The Coordinating Group has adopted this code of ethics as a guide to the dairy industry to be used uniformly throughout the industry, in order to maintain integrity, reliability and ethical use of dairy record data.
.~SS001~TION
The code of ethics provides guidelines for summary, evaluation and research use, information for publication, including labeling, nomenclature and selection of information, and sources and availability of record data. Specific requirements for publishing records of individual cows, sire summaries and herd averages are provided. 211. Using Milko-Tester located at central laboratories in state Dairy Herd Improvement record programs. E. C. Troutman, University of Kentucky, Lexington. Re-organization of Kentucky's Dairy Herd Improvement program involves the establishment of central laboratories, using a model MK I I Milko-Tester (Foss Electric, Denmark). Regional management areas and testing laboratories under a district manager have been initiated. Major advantages of the MilkoTester over the Babcock test are speed, accuracy, and convenience. Most problems are mechanical and fairly easy to locate and repair. Electrical problems are less frequent but more difficult to locate and repair. A new manual has aided in locating and solving problems. Major problems encountered during 18 months operation were stuck homogenizer piston, clogged pipette and homogenizer, leaking dispensing syringe, clogged and dirty cuvette, and current leaking stabilizer. Prevention and repair of these problems will be discussed. E12. Using Milko-Testers located at central laboratories in state Dairy Herd Improvement Association programs. H. C. Gilmore*, D. N. Putnam, and M. Kroger, The Pennsylvania State University, University Park. After investigations had been made on the feasibility of setting up county, district or statewide laboratories, a pilot program was started October 1, 1968 to determine the practicality of shipping milk samples to one statewide laboratory for milk fat testing using the Milko-Tester. Previous experience had shown that churning could be prevented by shipping samples in completely full containers without refrigeration. Disposable plastic bags in corrugated cardboard containers are being used to ship the milk samples by parcel post and by commercial carrier. Samples are being sent from twelve supervisors in seven counties from various locations throughout the state. Our experience to date shows that it is both economical and practical to ship preserved milk samples to one location for testing for milk fat. E13. Using Milko-Testers in Wisconsin in Dairy Herd Improvement Laboratories. E. E. Starkey, University of Wisconsin, Madison. Wisconsin has two Milko-Testers operating in central laboratories managed by our state
A~FAIaS
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Dairy Herd Improvement Association (Agricultural Records Cooperative). One has been in service since August 1967, used for testing 13,000 samples per month. The other unit has served for :12,000 samples per month since February 1968. Calibration and routine checking of the Milko-Tester has been a major concern and needs special attention. Although various mechanical problems have been experienced, they have been corrected. Adequate servicing of this machine does appear to need priority attention. Generally speaking, laboratory technicians enjoy using the Milko-Tester and would not want to return to the Babcock Method. E14. Effect of corral lighting on feed intake and milk production of dairy cattle. 1~. D. Murrill*, R. N. Eide, R. O. Leonard, and D. L. Bath, University of California, Davis. The effect of night lighting of corrals on feed intake and milk production was determined in three commercial dairies involving 264 head of dairy cows. Double-reversal designs were employed in each case. Treatment periods were for six weeks, the first week being used as an adjustment period. Mean milk production in the three trials were 18.72, 23.65, and 26.66 kg per day. Corral lighting resulted in increases of 0.04, 0.14, and .50 kg per day, respectively. Only the last difference was statistically significant at the 5% level. When milk production data from the three trials were pooled, a statistically significant increase of 0.22 kg per day resulted from the corral lighting treatment. Milk fat percentages were depressed 0.02, 0, and 0.03% respectively; none were significant. Mean roughage dry matter intakes were increased 1.22, 0.09, and 0.36 kg per day, respectively, in the three trials. Statistical analysis of roughage intake on an individual cow basis was not possible due to the common practice in commercial dairies of feeding roughage on a group basis.
215. Preliminary evaluation of a method of reducing mastitis infections in dairy cows. A. M. Meek ~, R. P. Natzke, G. H. Schmidt, W. G. Merrill, R. W. Everett, S. J. Roberts, and R. S. Guthrie~ Cornell University, Ithaca, New York. The paper describes a method of reducing the incidence of mastitis infection in dairy herds. I n 27 herds (1,900 cows) in New York state a research project is being carried out, using an effective teat dip material combined with the treatment of all quarters of dry cows to reduce new infections and to remove existing infections, respectively. There are 14 herds in free stall units and 13 herds in stall barns. I n a further division without housing type, half of the herds are receiving a hygiene program according to present recommendaJ. DAI~Y SClE~C~ VOL. 52, NO. 6
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tions except for teat cup treatment, whereas the other half of the herds are dependent on the teat-dip for sanitation. The teat-dip being used is a 4% NaOC1 solution with a maximum of 0.08% NaOH. The dry-cow treatment being used is a mixture of one million units of penicillin and one gram of streptomycin with 3% aluminum monostearate in peanut oil. The experiment will continue for three years. During 18 months the apparent reduction in infection as determined by bacteriological examination is about 75%.
El6. Dairy cost analysis in Dairy Herd Improvement (DHI) herds. W. R. Van Sant, University of Arizona, Tucson. The dairy cost analysis is a computerized program to provide dairymen with cost information for making management decisions. To expand the information for management purposes, this program has been adapted to D H I , providing a monetary value for the herd and individual cow records. This is a supplement to the D H I program and the computing center provides a herd summary and an individual cow report. On test day the supervisor reports daily feed and cost per ton, labor, latest market settlement stabement, and other permanent data. The computing center provides a herd analysis showing all cost per 100 lb 3.5% milk, return to management, feed cost per cow, break-even production, all compared to the average, low, and high cost per 100 lbs 3.5% milk of p a r t i c i p a t i n g herds. The individual cow records computed on a daily basis are m a r k e t value per hundredweight, gross value of daily milk, total daily production cost, net return, break-even production (total costs), break-even production (feed and market cost), monetary lactation values to date (plus or minus), extrapolated dollars and per cent mature equivalent relative value. El7. Disposable milk sample containers and carrying cases suitable for the Dairy Herd Improvement Program. I~. W. Eriekson, University of Minnesota, St. Paul. More central Dairy H e r d Improvement laboratories are being .established as the result of the introduction of the Foss Milk-O-Tester. Milk samples from extensive areas are being transported as several hundred samples are needed each day. Polyethylene plastic cups (147.85 ml or 5 oz) with snap-on lids are packed inside a 36-position polystyrene (Styro-
~. DAII~Y SOII~)TOEVOL. 52, ~IO. 6
foam) container. A polyvinyl wax-coated corrugated carton protects the Styrofoam during transportation of milk samples from f a r m to central testing facility. Such containers are superior to glass j a r s in t h a t they are lightweight, disposable, non-breakable, and more sanitary. The cups (one cent each) are used once and then discarded, whereas the polystyrene ($1.55 each) containers are used for at least 35 round trips between farms and laboratory. Styrofoam holds the cups rigid when they are filled and acts as an insulator against heat and cold. Samples of milk placed in these containers at 20 C withstood freezing for seven hours at --29 C. The cups withstood temperatures down to --50 C without cracking. ti18. New picture classes for 4-H dairy judging. R. E. Buffington, Virginia Polytechnic Institute, Blacksburg. F i f t y classes of four cows each of the five major dairy breeds were compiled for 4-1=[ Leaders and Extension youth agents for use in teaching dairy cattle judging. The ten classes per breed were composed of 40 outstanding cows within that breed. Each class is illustrated with five slides, one o f ' each individual cow and one of the group. There are also four black and white photographs (8.89 cm × 12.7 cm) of the individual cows mounted on poster board (21.59 cm × 27.94 cm). Each slide and photograph used is a copy of a professional picture published in a breed magazine. The official placing and scoring key plus the classification, production~ and outstanding type characteristics of each individual cow are outlined on the back of each poster. Pictures and slides of individual animals and classes aid in teaching the evaluation and comparison of d a i r y cattle.
E19. Teaching milking techniques. S. B. Spencer, Pennsylvania State University, University Park. The complexity of milking routines and the variety of milking systems make the teaching of milking procedures difficult. Moving pictures have been developed and employed to teach milking practices. Timed studies show that good procedures can result in milking times of under six minutes unit time per cow while poorly developed routines may require longer. The techniques used will be demonstrated.
J O U R N A L OF D A I R Y S C I E N C E
concentrations of blood urea nitrogen or blood ammonia; but a more rapid increase in blood urea nitrogen after feeding was observed for the UA than the other treatments. The data strongly suggests that intake depression observed on high-urea diets is due to the undesirable taste of urea and not ruminal or postruminal effects. P182. Urea-treated corn silage in low protein rations for lactating cows. J. T. Huber* and J. W. Thomas, Michigan State University, East Lansing. Corn silages (34 to 37% dry matter) onstied with: 1) no additive; 2) 0.5% urea; 3) 0.75% urea; and 4) 0.75% urea -~ 0.17% CaSO, were fed as the only forage to 60 heavily lactating cows (10/group) for 70 days. Concentrates containing 8, 12, or 18% CP were also fed at 1 kg/3 kg milk. Treatments, designated by silage number and per cent CP in concentrate, were: Group A 1, 8; Group B 1, 18; Group C 2, 8; Group D 2, 12; Group E 3, 8, and Group F 4, 8. Nitrogen balances were determined on 5 cows/group at the end of the feeding period. Milk yields (kg/day) and persistencies (%) for the respective treatments averaged 19.2, 67; 25.7, 88; 23.7, 81; 26.4, 91; 23.8, 82; 23.9, 84. Group A was lower (P<0.05) than all others, with Group C and E lower (P~0.05) than D. Total dry matter and silage dry matter intakes (kg/100 kg body weight) averaged, respectively, 2.4, 1.2; 2.8, 1.6; 2.7, 1.4; 3.0, 1.6; 2.7, 1.5; 2.8, 1.5. Silage intake of Group A was lower (P~0.05) than Groups B and D. Balance data showed the negative Controls A excreted 142% of their digested nitrogen as milk and urine, while other groups averaged 89 to 109%.
P183. Lactation comparisons of alfalfa meal and urea as the nitrogen supplement. H. R. Conrad*, J. W. Hibbs, and V. A. Neuhardt, Ohio Agricultural Research and Development Center, Wooster. Sixty-six per cent alfalfa meal, 31.6% urea, 2.0% dicalcium phosphate, and 0.4% sodium propionate were mixed and pelleted for ira-
EXTENSION E l . N e w developments in production testing. F. N. Dickinson, Animal Husbandry Research Division, USDA, Beltsville, Maryland. A technical subcommittee of the National DHIA Coordinating Group has been formed to coordinate research on testing plans and methods for estimating yield. The committee decided that major problems facing it were estimation of milk and milk fat yield under alternate AM-PM sampling plans; adjustment of lactation milk and milk fat yields at start and J. DAIRY SOII~C~ VOL. 52, NO. S
proving the edibility of urea containing feeds while sustaining maximum tureen synthesis. This supplement (Dehy-100) contained 16% nitrogen. When 10% of Dehy-100 was added to grain concentrate, crude protein content was raised to 18%. In a switchback experiment comparing Dehy-100 with soybean meal in isonitrogenous diets, ten Holstein cows fed Dehy-100 produced an average of 7,933 kg of milk, 280 kg of fat, and 7,357 +---805 kg of 4% fat-corrected milk; consumed 3,873 -----481kg of digestible dry matter; and used 32% of the intake nitrogen for milk. The values for soybean meal feeding were 7,946 -+- 267, 7,182 ~927 and 3,614 ± 409 kg, and 33%, respectively. The maintenance of high productivity in cows fed Dehy-100 demonstrated its usefulness as a substitute for vegetable protein. P184. Dietary protein levels for milking cows. J. W. Thomas, Michigan State University, East Lansing. A corn silage-alfalfa hay-concentrate ration containing 10 to 11 or 13% protein was fed to 22 cows beginning 45 days postpartum and continued for two lactations. Milk:grain ratio was 2:1. From 45 to 305 days postpartum cows fed 10 to 11% protein produced 2.0 kg milk/cow/day less than projected and those fed 13% produced 3.4 kg more. Compared to their previous lactation, eight cows fed 10 to 11% protein produced 1.3 kg less and six cows fed 13% produced 5.4 kg more per cow per day. During the second lactation eight cows fed 10 to 11% protein averaged 6,562 (range, 3,900 to 9,581) kg milk and six fed 13% protein 7,851 (range, 6,257 to 9,266) kg or ]02 and 95% of their first experimental lactation. Monthly persistency for first lactation was 90 versus 94% and for second lactation 93 versus 95% respectively. In a 90day trial 16 cows at 180 days postpartum were fed the 10 or 13% rations. Fat-corrected milk production was ]7.6 versus 17.0 kg/cow/day for those fed 10 and 13% respectively. After mid-lactation a ration of 10% protein is adequate but for the entire lactation some cows require a higher level of dietary protein.
SECTION
end of lactation under TIM ; parameters of daily milk fat variation; definition of acceptable tolerances for errors in estimates of yield, and; modifications to standard DHI rules to make them compatible with TIM. The last problem is the only one that has been mostly resolved. Progress has been made towards solving the other problems for lactation milk yield. Little progress has been made on any of the problems of milk fat yield or the errors found in, or acceptable tolerances for,
ASSOCIATION AFFAIRS
periodic milk weights. D a t a are available for studies on milk. Data must be collected for studies on milk fat. F a r greater resources than are presently available to this committee must be devoted to the timely solution of these problems. E2. Alternate AM-PM testing for Dairy Herd Improvement Association programs--operational procedures. D. N. P u t n a m ~ and H. C. Gilmore, The Pennsylvania State University, University Park. I n slightly less than four months from the time the a~ternate A~-P~ plan of testing was approved by the Pennsylvania Directors as an optional program, nearly 800 dairymen in 40 of Pennsylvania's 67 counties changed from the conventional twice-daily weighing and sampling on test day to the alternate A~-P~ plan. More than 75% of these herds were enrolled on official D H I test. Some counties adjusted fee schedules to provide a price differential for alternate AM-P~ testing, others did not. Generally the alternate plan fees are about 80% as much as the charges for the conventional program. The single milk weight is recorded on the barn sheet and doubled by data processing. The supervisor records whether milking is AI~ or P1/i which is printed on the dairymen's report. Lactation records are reported to USDA as unofficial records but by action of the state D t I I A directors lactation and herd records can be used for county and statewide publicity when properly labeled. E3. Thyroprotein feeding--research findings and application in dairy herd management. J. W. Thomas, Michigan State University, E a s t Lansing. Giving extra thyroid hormone temporarily increases milk production and this effect is more prolonged if additional feed is also .given. Fat-corrected milk increase ( k g / d a y ) is nonsignificantly related to days in milk (X1), age in months (X2) and production level (X3) when thyroxine treatment is initiated. Fat-corrected milk increase ( l b / d a y over 60 days) ---- 1.3 + 0.01 X 1 + 0.012 X2 -0.01 X 3. F a t test m a y also be increased but it is not sufficiently related to any factor that can be used to estimate response. Cvenerally, the largest increase in test and largest fatcorrected milk increase on a percentage basis occurred in cows having the smaller milk yield. There is an extremely large variation in response among cows within a herd and between herds. Cows that respond the most also have the largest decrease when thyroxine is discontinued. Over an entire lactation no measurable differences in production are likely to be found due to thyroprotein feeding. Reproductive performance and health of cows is not notably altered although temperature, respiration and heart rates are increased.
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E4. Genetic evaluations in action. B. R. Eastwood*, D. E. Voelker, and A. E. Freeman, Iowa State University, Ames. A selection index for t r a n s m i t t i n g ability was applied to milk and f a t records of more than 300,000 cows in 6,290 herds in eight states which have records processed at Iowa State University. A total of 1,076,221 lactations, including those in progress 45 days or more, was used in the calculations. Deviations of 305-2 time-mature equivalent lactations from herdmates (within breed, herd, and year-season) of the cow, paternal s~sters, dam, daughters, and maternal sisters were used in calculating the estimated average transmitting ability of each cow. Dairymen were provided within-herd rankings of their cows and a comparison of sire averages, selection differentials for estimated average transmitting ability, and other management criteria with state breed averages. Sixty-two educational meetings were conducted with Iowa dairymen during early 1969, emphasizing genetic evaluation of the herd and the application of the cow's estimated average t r a n s m i t t i n g ability and s i r e ' s - P r e dicted Difference in evaluating potential matings and offspring. B5. Bffect of genetic t r e n d on first summary of artificial insemination sampled sires and succeeding summaries. H. W. Carter, Cornell University, Ithaca, New York. Records of 14,500 daughters of 19 young sires, randomly sampled in artificial insemination, and returned to service as a result of the production of their first daughters, were studied to determine the effect of genetic trend on the level of their second crop of daughters. These 19 sires were selected from a total group of 80 sampled. The average superiority over herdmates of the first crop of daughters was plus 125 kg of milk. F i v e years later, these selected sires had a second crop of daughters. Their average superiority over herdmates was plus 7 kg of milk. This is a decrease of 118 kg of milk which is an average drop of 24 kg a year. The correlation of the second summary to the first summary was .8166, indicating a good degree of accuracy for the first selection which was based on a limited number of daughters. The average number of daughters p e r sire in the first summary was 69 and in the second 694. E6. Relation between initial and later United States Department of Agriculture--Dairy Herd Improvement Association sire summaries. B. T. McDaniel* and F. 1~. Dickinson, Animal H u s b a n d r y Research Division, USDA, Beltsville, Maryland. Predicted Differences (PD) from USDAD t t I A Sire Summaries of A p r i l 1967 and based on 50 progeny or less were defined as the initial summary (X) in all cases. IndeJ . DAIRY SCIEI~CE Vor.. 52, NO. 6
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pendent l a t e r summaries (Y) were computed by subtracting the initial from the latest. Comparisons were made only where the reliability of Y was ~ X. Analysis I contained 51 bulls with X based on non-artificial insemination (AI) progeny only (avg repeatability, ---- .38). Analysis I I contained 47 bulls with X based on A I progeny only (R = .52). All later summaries were based on A I progeny only. Correlations between X and Y for PD for milk yield were 0.67 versus an expected r of 0.52 in I, and 0.71 versus an r of 0.61 in II. Regressions of Y on X for PD (milk) were ] . 0 9 ± 0 . 1 7 in I and 0 . 9 0 - . 0 . 1 3 in II. F o r f a t yield, r's were 0.69 and 0.64, and b's were 0.98 ± 0.15 and 0.88 ± 0.16, respectively. F o r f a t percentage (deviation from herdmates), r's were 0.76 and 0.80, and b's were 0.55 ± .07 and 0.76 -* .09. Bias in PD (milk) was 51 kg in I versus --16 kg in I L The initial PD was the best predictor of each measure of breeding value for milk and f a t studied in the later summary. E7. Selection differentials of sires of bulls used in Dairy Herd Improvement Association herds. R. H. Miller ~, B. T. McDaniel, F. 51. Dickinson, and V. H. Lytton, Animal Husbandry Research Division, USDA, Beltsville, Maryland. All sire-son pairs with Predicted Difference (PD) data available as of September 1967 were studied to assess the amount of s.election practiced in choosing bulls for service. The numbers of sire-son pairs were as follows: Ayrshire, 684; Guernsey, 3,519; Holstein, 11,372; Jersey, 2,590; and Brown Swiss, 555. The sire's proof was repeated for each of his sons to obtain selection differentials weighted by the number of offspring. The mean weighted selection differentials for PD milk were as follows: Ayrshire, --46 kg; Guernsey, --12 kg; Holstein, --30 kg; Jersey, + 1 3 kg; and Brown Swiss, --14 kg. Selection differentials for f a t per cent were uniformly positive, ranging from .03% to .05%. The 15 Holstein sires with PD's for milk above 453.6 kg had a total of 176 sons whose PD's for milk averaged 82.6 kg. Only 39.5% of the Holstein bulls with summarized sons had PD's for milk yield above breed average. E8. Relative selection differentials of sires of artificial insemination ( A I ) bulls for production traits. 1T. H. Lytton*, R. H. Miller, B. T. McDaniel, and F. 51. Dickinson, Animal H u s b a n d r y Research Division, USDA, Beltsville, Maryland. All pairs of sires and their A I sons with Predicted Difference (PD) data available as of September 1967 were utilized to determine the degree of selection practiced in choosing bulls for use in AI. The numbers of sire-AI son pairs were 1.09 Ayrshire, 628 'Guernsey, J. DAIRY SCIENCE VOL. 52, NO. 6
1,503 Holstein~ 447 Jersey, and 164 Brown Swiss. The sire's evaluation was repeated for each of his sons to obtain relative selection differentials weighted by the number of sons. The mean weighted selection differentials for A I bulls for PD milk ranged from --42 to 55 kg among the breeds. Mean PD's of the sons ranged from --20 to 5 kg. Selection differentials were generally positive for f a t yield (0 to 2 kg), and p e r cent f a t (--0.01 to .10%). The apparent superiority for PD milk yield of the sires of A I bulls over the sires of non-AI bulls ranged from 5 kg to 50 kg for the five breeds. Superiority for PD fat ranged from 1 to 2 kg, and for f a t per cent from 0.00 to 0.03%. F u t u r e A I bulls can and should possess a much higher selection differential for yield traits. E9. ]~stimates of sire-son relationships for yield traits in the five major dairy breeds. F. 5I. Dickinson*, B. T. McDaniel, R. H. Miller, and V. H. Lytton, Animal HusbandiT. Research Division, USDA, Beltsville, Maryland. The number of sire-son pairs for the five major d a i r y breeds were: Ayrshire, 684; Guernsey, 3,505; Holstein, 10,828; Jersey, 2,590; Brown Swiss, 555. Gross correlations between Predicted Differences (PD) for milk were 0.22, 0.25, 0.28, 0.33, and 0.14 for the five breeds respectively. F o r PD f a t r's were 0.23, 0.28, 0.26, 0.28, and 0.16. F o r f a t per cent (deviation from herdmates) r's were 0.24, 9.29, 0.30, 0.30, and 0.31. Gross regressions of PD-son on PD-sire were for milk, 0.14 ± .02, 0.18 ± .01, 0.19 ±.01, 0.23 ± . 0 1 , and 0.]3 ± . 0 4 ; for fat, 0.14 + .02, 0.18-* .01, 0.18 ± .01, 0.19 ± .01, and 0.15 -* .04; and for f a t per cent (deviation), 0.31 -*.05, 0.33 *- .02, 0.37 -* .01, 0.35 -* .02 and 0.38 -* .05. Sire-son correlations of PD's were higher than those based on unadjusted devia£ions from herdmates by 0.02 to 0.06 in all breeds except Brown Swiss. Correlations of sire-son PD's in Holsteins increased as r e p e a t a b i l i t y level of both sire and son increased. Even at the lowest repeatability categories the sire's PD was a useful predictor of the son's PD. El0. Progress report concerning a code of ethics for use of Dairy Herd Improvement Program results. D. E. Voelker, Iowa State University, Ames. During the p a s t two years, a special committee under the Coordinating Group of the National Cooperative Dairy H e r d Improvement Program has developed a code of ethics on the availability and use of d a i r y production records. The Coordinating Group has adopted this code of ethics as a guide to the dairy industry to be used uniformly throughout the industry, in order to maintain integrity, reliability and ethical use of dairy record data.
.~SS001~TION
The code of ethics provides guidelines for summary, evaluation and research use, information for publication, including labeling, nomenclature and selection of information, and sources and availability of record data. Specific requirements for publishing records of individual cows, sire summaries and herd averages are provided. 211. Using Milko-Tester located at central laboratories in state Dairy Herd Improvement record programs. E. C. Troutman, University of Kentucky, Lexington. Re-organization of Kentucky's Dairy Herd Improvement program involves the establishment of central laboratories, using a model MK I I Milko-Tester (Foss Electric, Denmark). Regional management areas and testing laboratories under a district manager have been initiated. Major advantages of the MilkoTester over the Babcock test are speed, accuracy, and convenience. Most problems are mechanical and fairly easy to locate and repair. Electrical problems are less frequent but more difficult to locate and repair. A new manual has aided in locating and solving problems. Major problems encountered during 18 months operation were stuck homogenizer piston, clogged pipette and homogenizer, leaking dispensing syringe, clogged and dirty cuvette, and current leaking stabilizer. Prevention and repair of these problems will be discussed. E12. Using Milko-Testers located at central laboratories in state Dairy Herd Improvement Association programs. H. C. Gilmore*, D. N. Putnam, and M. Kroger, The Pennsylvania State University, University Park. After investigations had been made on the feasibility of setting up county, district or statewide laboratories, a pilot program was started October 1, 1968 to determine the practicality of shipping milk samples to one statewide laboratory for milk fat testing using the Milko-Tester. Previous experience had shown that churning could be prevented by shipping samples in completely full containers without refrigeration. Disposable plastic bags in corrugated cardboard containers are being used to ship the milk samples by parcel post and by commercial carrier. Samples are being sent from twelve supervisors in seven counties from various locations throughout the state. Our experience to date shows that it is both economical and practical to ship preserved milk samples to one location for testing for milk fat. E13. Using Milko-Testers in Wisconsin in Dairy Herd Improvement Laboratories. E. E. Starkey, University of Wisconsin, Madison. Wisconsin has two Milko-Testers operating in central laboratories managed by our state
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Dairy Herd Improvement Association (Agricultural Records Cooperative). One has been in service since August 1967, used for testing 13,000 samples per month. The other unit has served for :12,000 samples per month since February 1968. Calibration and routine checking of the Milko-Tester has been a major concern and needs special attention. Although various mechanical problems have been experienced, they have been corrected. Adequate servicing of this machine does appear to need priority attention. Generally speaking, laboratory technicians enjoy using the Milko-Tester and would not want to return to the Babcock Method. E14. Effect of corral lighting on feed intake and milk production of dairy cattle. 1~. D. Murrill*, R. N. Eide, R. O. Leonard, and D. L. Bath, University of California, Davis. The effect of night lighting of corrals on feed intake and milk production was determined in three commercial dairies involving 264 head of dairy cows. Double-reversal designs were employed in each case. Treatment periods were for six weeks, the first week being used as an adjustment period. Mean milk production in the three trials were 18.72, 23.65, and 26.66 kg per day. Corral lighting resulted in increases of 0.04, 0.14, and .50 kg per day, respectively. Only the last difference was statistically significant at the 5% level. When milk production data from the three trials were pooled, a statistically significant increase of 0.22 kg per day resulted from the corral lighting treatment. Milk fat percentages were depressed 0.02, 0, and 0.03% respectively; none were significant. Mean roughage dry matter intakes were increased 1.22, 0.09, and 0.36 kg per day, respectively, in the three trials. Statistical analysis of roughage intake on an individual cow basis was not possible due to the common practice in commercial dairies of feeding roughage on a group basis.
215. Preliminary evaluation of a method of reducing mastitis infections in dairy cows. A. M. Meek ~, R. P. Natzke, G. H. Schmidt, W. G. Merrill, R. W. Everett, S. J. Roberts, and R. S. Guthrie~ Cornell University, Ithaca, New York. The paper describes a method of reducing the incidence of mastitis infection in dairy herds. I n 27 herds (1,900 cows) in New York state a research project is being carried out, using an effective teat dip material combined with the treatment of all quarters of dry cows to reduce new infections and to remove existing infections, respectively. There are 14 herds in free stall units and 13 herds in stall barns. I n a further division without housing type, half of the herds are receiving a hygiene program according to present recommendaJ. DAI~Y SClE~C~ VOL. 52, NO. 6
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tions except for teat cup treatment, whereas the other half of the herds are dependent on the teat-dip for sanitation. The teat-dip being used is a 4% NaOC1 solution with a maximum of 0.08% NaOH. The dry-cow treatment being used is a mixture of one million units of penicillin and one gram of streptomycin with 3% aluminum monostearate in peanut oil. The experiment will continue for three years. During 18 months the apparent reduction in infection as determined by bacteriological examination is about 75%.
El6. Dairy cost analysis in Dairy Herd Improvement (DHI) herds. W. R. Van Sant, University of Arizona, Tucson. The dairy cost analysis is a computerized program to provide dairymen with cost information for making management decisions. To expand the information for management purposes, this program has been adapted to D H I , providing a monetary value for the herd and individual cow records. This is a supplement to the D H I program and the computing center provides a herd summary and an individual cow report. On test day the supervisor reports daily feed and cost per ton, labor, latest market settlement stabement, and other permanent data. The computing center provides a herd analysis showing all cost per 100 lb 3.5% milk, return to management, feed cost per cow, break-even production, all compared to the average, low, and high cost per 100 lbs 3.5% milk of p a r t i c i p a t i n g herds. The individual cow records computed on a daily basis are m a r k e t value per hundredweight, gross value of daily milk, total daily production cost, net return, break-even production (total costs), break-even production (feed and market cost), monetary lactation values to date (plus or minus), extrapolated dollars and per cent mature equivalent relative value. El7. Disposable milk sample containers and carrying cases suitable for the Dairy Herd Improvement Program. I~. W. Eriekson, University of Minnesota, St. Paul. More central Dairy H e r d Improvement laboratories are being .established as the result of the introduction of the Foss Milk-O-Tester. Milk samples from extensive areas are being transported as several hundred samples are needed each day. Polyethylene plastic cups (147.85 ml or 5 oz) with snap-on lids are packed inside a 36-position polystyrene (Styro-
~. DAII~Y SOII~)TOEVOL. 52, ~IO. 6
foam) container. A polyvinyl wax-coated corrugated carton protects the Styrofoam during transportation of milk samples from f a r m to central testing facility. Such containers are superior to glass j a r s in t h a t they are lightweight, disposable, non-breakable, and more sanitary. The cups (one cent each) are used once and then discarded, whereas the polystyrene ($1.55 each) containers are used for at least 35 round trips between farms and laboratory. Styrofoam holds the cups rigid when they are filled and acts as an insulator against heat and cold. Samples of milk placed in these containers at 20 C withstood freezing for seven hours at --29 C. The cups withstood temperatures down to --50 C without cracking. ti18. New picture classes for 4-H dairy judging. R. E. Buffington, Virginia Polytechnic Institute, Blacksburg. F i f t y classes of four cows each of the five major dairy breeds were compiled for 4-1=[ Leaders and Extension youth agents for use in teaching dairy cattle judging. The ten classes per breed were composed of 40 outstanding cows within that breed. Each class is illustrated with five slides, one o f ' each individual cow and one of the group. There are also four black and white photographs (8.89 cm × 12.7 cm) of the individual cows mounted on poster board (21.59 cm × 27.94 cm). Each slide and photograph used is a copy of a professional picture published in a breed magazine. The official placing and scoring key plus the classification, production~ and outstanding type characteristics of each individual cow are outlined on the back of each poster. Pictures and slides of individual animals and classes aid in teaching the evaluation and comparison of d a i r y cattle.
E19. Teaching milking techniques. S. B. Spencer, Pennsylvania State University, University Park. The complexity of milking routines and the variety of milking systems make the teaching of milking procedures difficult. Moving pictures have been developed and employed to teach milking practices. Timed studies show that good procedures can result in milking times of under six minutes unit time per cow while poorly developed routines may require longer. The techniques used will be demonstrated.