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Effects of forage family (legume vs. grass) on apparent ruminal synthesis (ARS) and postruminal supply of B vitamins were evaluated in 2 experiments. Diets containing either alfalfa (AL) or orchardgrass (OG) silages as the sole forage were offered to ruminally and duodenally cannulated lactating Holstein cows in crossover design experiments. Experiment 1 compared diets containing AL and OG [~23% forage neutral detergent fiber (NDF) and ~27% total NDF] offered to 8 cows in two 15-d treatment periods. Experiment 2 compared diets containing AL and OG (~25% forage NDF and ~30% total NDF) offered to 13 cows in two 18-d treatment periods. Thiamin, riboflavin, niacin, vitamin B6, folates, and vitamin B12 were analyzed in feeds and duodenal digesta. Apparent ruminal synthesis was calculated as the duodenal flow of each vitamin minus its intake. Forage family affected B vitamin intakes, duodenal flow, and ARS. In both experiments, AL diets increased vitamin B6 and decreased folate intakes. In experiment 1, riboflavin and niacin intakes were greater with the OG diet, whereas in experiment 2 thiamin intake was greater but riboflavin intake was smaller with the OG diet. In spite of the low contribution of either silage to the dietary folate content, folate intake was greater with OG diets than AL due to the difference in soybean meal contribution between diets. Niacin and folate ARS were not affected by the forage family. Duodenal microbial nitrogen flow was positively correlated with ARS of riboflavin, niacin, vitamin B6, folates, and vitamin B12, but tended to be negatively correlated with thiamin ARS. Apparent ruminal synthesis of folates and vitamin B12 appear to be related to microbial biomass activity. Changes in nutrient composition of the diets likely affected the microbial population in the rumen and their B vitamin metabolism.

Previous research in our laboratory has indicated that the physical filling effects of high-forage diets become increasingly dominant in determining feed intake and milk production as nutrient demand increases. This effect was tested further by using 14 ruminally and duodenally cannulated Holstein cows in a crossover design experiment with a 14-d preliminary period and two 15-d experimental periods. During the preliminary period, 3.5% fat-corrected milk yield was 15 to 60 kg/d (mean = 40 kg/d), and preliminary voluntary dry matter intake (pVDMI) was 20.6 to 30.5 kg/d (mean = 25.0 kg/ d). Treatments were a low-forage diet (LF), containing 20% (dry matter basis) forage neutral detergent fiber (NDF), and a high-forage diet (HF), containing 27% forage NDF. The ability of linear and quadratic factors of pVDMI to predict the difference in responses of individual cows to treatments (Y LF -Y HF ) was tested by ANOVA, with treatment sequence as a covariate. In contrast to results of previous research, differences in dry matter intake and fat-corrected milk yield responses to LF and HF did not depend on pVDMI. This might be because of the combined physical fill and metabolic satiety effects of LF, especially in cows with the greatest pVDMI. Digestion or passage of NDF might have been inhibited on LF among high-pVDMI cows. As pVDMI increased, NDF turnover time increased more on LF than on HF. Among high-pVDMI cows, the NDF turnover time was unexpectedly greater on LF than on HF. With increasing pVDMI, the digestion rate of potentially digestible NDF decreased at a similar rate on both diets. Passage rates of potentially digestible NDF and indigestible NDF were not related to pVDMI, regardless of treatment. Greater starch fermentation (resulting from greater starch intake) for LF as pVDMI increased likely inhibited NDF digestion through pH-dependent and pH-independent effects. Inhibition of NDF digestion might cause LF and HF to have similar effects on dry matter intake, depending on the nutrient demand of individual cows.

The effects of increasing concentrations of dried, pelleted beet pulp substituted for high-moisture corn on intake, milk production, and chewing behavior were evaluated using eight ruminally and duodenally cannulated multiparous Holstein cows in a duplicated 4 × 4 Latin square design with 21-d periods. Cows were 79 ± 17 (mean ± SD) d in milk at the beginning of the experiment. Experimental diets with 40% forage (corn silage and alfalfa silage) and 60% concentrate contained 0, 6.1, 12.1, or 24.3% beet pulp substituted for high-moisture corn on a dry matter basis. Diet concentrations of neutral detergent fiber (NDF) and starch were 24.3 and 34.6% (0% beet pulp), 26.2 and 30.5% (6% beet pulp), 28.0 and 26.5% (12% beet pulp), and 31.6 and 18.4% (24% beet pulp), respectively. Increasing beet pulp in the diet caused a linear decrease in dry matter intake (DMI). Time spent eating per day and per kilogram of DMI increased, and sorting against NDF tended to increase, with added beet pulp. Substituting beet pulp for corn caused a quadratic response in milk fat yield, with the highest yield for the 6% beet pulp treatment. A tendency was detected for a similar quadratic response in 3.5% fat-corrected milk yield. Lower plasma insulin concentration may have resulted in lower body condition gain for cows fed diets with higher beet pulp concentration. Partial substitution of pelleted beet pulp for high-moisture corn decreased intake but also may have permitted greater fat-corrected milk yield.

A switchback design experiment with eight cows was used to evaluate wet corn distillers grains (33.9% dry matter) as a feed for lactating cows. All cows were fed corn silage ad libitum and 3.2kg of alfalfa hay daily. Cows on the control diet were fed an 18.6% crude protein concentrate mix of corn, oats, and soybean meal at 1 kg/2.5kg milk produced. Cows on the experimental diet were fed 13.6kg wet distillers grains (34% crude protein, dry) and a 10.9% crude protein concentrate mix of corn and oats at 1 kg/2.5kg milk produced in excess of 11kg milk daily. The reduced amount and reduced protein content of the concentrate mix fed to cows on the experimental ration was to compensate for protein and energy consumed as wet distillers grains. Cows averaged 12 wk postpartum at the start of the experiment, which consisted of three 4-wk periods. Cows fed control and wet distillers grains rations produced 27.0 and 27.6kg of milk daily. No differences in milk fat (3.44 and 3.41%), milk protein (3.09 and 3.10%), or total solids (12.1 and 12.16%) were observed. Total dry matter consumption was similar for control and wet distillers grains rations (20.3 and 20.8kg dry matter/day). Rumen volatile fatty acids, pH, and ammonia were similar for cows fed control and distillers grains rations. Wet distillers grain can be effective in rations for lactating dairy cattle as a protein and energy source.

Alfalfa-brome hay, haylage, .5% urea-treated corn silage, or .5% urea plus 1% dried whey-treated corn silage was fed as the only forage to one of four groups of 10 lactating cows per group for a lactation trial of 10 wk. Rumen samples were collected via stomach tube 3 to 4 h after the morning feeding. The pH of the rumen samples from cows fed hay was higher than for cows fed haylage, urea-treated corn silage, and urea-whey corn silage, 6.69 versus 6.36, 6.40, and 6.50. Total volatile fatty acids and propionate were highest from cows fed urea-whey corn silage and were higher on all three fermented forages than cows fed hay. Acetate/propionate ratio was highest from cows fed hay and lowest from cows fed corn silages. Butyrate was highest from cows fed haylage or hay. Milk protein composition was not affected by ration although nonprotein nitrogen of milk was highest from cows fed the urea-treated corn silages. Oleic acid and total unsaturated fatty acids were lowest in milk fat from cows fed hay while palmitic acid was highest from cows fed hay and haylage. These results suggest that type of forage fed may cause small changes in rumen fermentation and in milk composition. The importance of these changes is unknown but may affect properties of dairy products produced from this milk.

Oats and a mixture of oats, barley, and wheat were grown on comparable plots and harvested in early dough stage as silage in each of 2 yr. Low moisture oat silage (oatlage) yielded 8533 and 7490 kg dry matter per ha in 2 yr compared to 9206 and 8004 kg for oats, barley, and wheat silage. Chemical composition of oatlage and silage were similar despite yearly variations. The silages were fed to 16 and 20 lactating cows in yr 1 and 2, respectively, to four steers for a digestion trial in year 1, and to 20 heifers in yr 2. Cows and heifers consumed more dry matter from silage than from oatlage. Milk production was higher when cows were fed silage than when they were fed oatlage in yr 1 (18.5 versus 19.3 kg/day) but was not different in yr 2 (19.9 versus 19.9 kg/day). Milk composition was not affected in either year. Digestibilities by steers and growth rates by heifers were similar when they were fed either oatlage or mixed silage.

A 75-yr history of the development of Dairy Herd Improvement Associations in the United States includes early cow testing efforts, involvement of the American Dairy Science Association, and activities of Cooperative Extension Service and United States Department of Agriculture personnel. Changes in organizational structure, improvement in methods and equipment, and expanding uses of data are documented. Enrollment and production improvement data are summarized.

Dried whey was added at 0, 1, and 10% to first cutting chopped alfalfa hay. The material was reconstituted with approximately 50% water and ensiled in experimental silos. Addition of whey increased lactic acid, decreased acetic acid, and reduced pH of the hay silages. Characteristics of desirable fermentation were usually best in 10% whey-treated hay silages. Acid-detergent fiber, cell wall contents, and cellulose were lower in hay silages treated with whey. No differences in fiber nitrogen were among treatments. Results of a digestion trial with four Holstein steers indicated apparent digestibilities of dry matter, ether extract, energy, cellulose, lignin, and hemicellulose increased with whey addition. Whey also increased digestibilities of cell wall contents and ash. Digestibilities were generally highest for 10% whey-treated hay silage, except cellulose digestibility was highest for 1% whey. Digestibility of protein in hay silages was not influenced by whey treatment.

Summary The feeding of several surface-active agents had no significant influence on the growth rates of dairy calves when fed either in a milk replacement diet or in a concentrate mixture. Moreover, the detergents had no consistent effect on hay and concentrate consumption, incidence of diarrhea, fecal pH, blood plasma fat levels, or on hemoglobin, erythrocyte, leucocyte and differential leucocyte values of the blood. The addition of surface-active agents and of penicillin to distilled water and to rumen fluid caused relatively large reductions in surface tension, whereas aureomycin and terramycin had no appreciable influence on the surface tension of these liquids.

Summary The comparative effects of feeding aureomycin, terramycin, and penicillin (Experiment I) and terramycin, bacitracin, Chloromycetin, and 3-nitro-4-hydroxy phenyl arsonic acid (Experiment II) to dairy calves were evaluated. Mean body weight gains over a 12-week period as per cent of the mean gains of the controls were: Experiment I, terramycin, 155%; aureomycin, 151%; and penicillin, 86%; Experiment II, terramycin, 135%; arsonic acid, 128%; bacitracin, 126%; and Chloromycetin, 111%. The treatments that stimulated growth also improved efficiency of feed utilization. The most rapidly gaining groups also attained greater height at withers and appeared somewhat superior in condition and hair coat at completion of the experiment; however, these differences were not marked. No pronounced ration effects were noted on incidence and severity of diarrhea, although both were relatively high during weeks 3 to 5, inclusive. Blood cell counts (erythrocytes, leucocytes, and differential leucocytes), hemoglobin, plasma fat, and fecal pH appeared to be unaffected by antibiotic or arsenical supplementation. Also, there was no apparent effect of diarrhea on fecal pH. Rather marked age trends in the blood constituents were noted.

Nutritive qualities of high-sugar male sterile hybrid corn and regular dent hybrid corn silages were compared over 2 yr with growing Holstein steers and lactating cows. Silage yield and harvesting data were obtained both years. High-sugar corn silage contained more crude protein than regular silage, 8.59 versus 6.34% of dry matter. Silage dry matter yields per hectare were greater for regular corn in year 1, but greater for high-sugar corn the second yr. Two groups of 12 Holstein steers were fed the respective silages ad libitum and 1.81kg of a 13.2% crude protein supplement per head per day. Silage dry matter intake and average daily gain did not differ between groups: 5.32 and 1.02 versus 5.48 and .93kg/day for the high-sugar and regular corn fed groups. Apparent digestibilities of protein and fiber were greater for the high-sugar corn silage: 63.5 versus 52.2% and 61.9 versus 59.3%, respectively. During year 2, 20 cows were included in a switchback design to compare regular with high-sugar corn silage for lactation. Cows fed regular corn silage produced more milk (17.5 versus 16.55kg/day) and solids-corrected milk (18.03 versus 16.79 kg/day) than those fed high-sugar corn silage. No differences in dry matter intake, milk fat production, or body weight changes were detected.

Two feeding trials using 20 cows each compared high dry matter corn silage (HDMCS) with corn silage of medium dry matter content (MDMCS). A continuous design was employed in Trial I and a double-reversal design in Trial II. The high dry matter corn silage was ground before ensiling and both silages stored in gas-tight units. Significant differences associated with the harvesting of high dry matter corn silage when compared with the medium dry silage include: lower dry matter yields; greater field dry matter losses; higher percentage of ear losses; lower carotene content; lower total acid concentration during fermentation; and a higher pH. Voluntary dry matter consumption, milk production, and body weight gains were greater for cows fed the high dry matter corn silage, but differences were significant only for Trial II. There were no significant differences in per cent milk fat or solids-not-fat between treatments. No consistent difference in chemical composition of the silages between years was found. The digestibility of the dry matter, energy, and protein for the medium and high dry matter silages was 66.9, 66.7, and 54.7; and 64.7, 65.4, and 51.1%, respectively. The silages were nearly equal in feed value; however, the disadvantages suggest that general recommendations for delaying harvest were not warranted.

Alfalfa from the same field was preserved as good and molded hay. Molded hay was prepared by sprinkling water (equivalent to 7.6cm rainfall) over the bales and stacking outdoors. Temperature inside the molded hay bales reached a maximum of 57 to 64C within 36 to 48 hr and subsided to atmospheric temperature in 15 days, while little temperature change was found in the good hay. Brownish coloration intensified as the temperature increased in the molded hay. Significant changes in the chemical composition of alfalfa due to mold action included lowered dry matter, ether extract, and nitrogen-free extract and higher pH, ash, and ammoniacal nitrogen. Two groups of five Holstein steers each were used in a double-reversal design feeding trial to evaluate experimental forages. Molded hay feeding produced the following changes: 1) lower dry matter intake; 2) reduced body weight gain; 3) lower total VFA concentration; 4) lower percentage of rumen propionic, isobutyric, isovaleric, and valeric acids; 5) lower rumen ammonia concentration; 6) higher percentage of rumen acetic acid; 7) higher rumen pH. Reduced total ruminal protozoa with a depression of Isotricha, Dasytricha , and Entodinium spp. was found while the percentage of Diplodinium increased with molded hay feeding. The digestibilities of the dry matter, energy, and protein for good and molded hay were 63.7, 63.1, and 76.9; and 53.7, 54.5, and 53.0%, respectively. Mold activity decreased feed value of alfalfa for dairy steers by 25 to 30%.

Three trials with Brown Swis and aged Holstein cows were conducted with Leptaden (extracts of plants— Leptadenia reticulata and Breynia patens ) added to a standard ration. The cows were in late, early, and middle stages of lactation in Trials 1, 2, and 3, respectively. Following three weeks pretreatment, cows in the Leptaden group were administered 10 Leptaden tablets (268 mg/tablet) twice daily in the first trial and 15 tablets twice daily in the second and third trials for 21 days. This period was succeeded by a three week post-treatment period. Leptaden feeding did not produce any significant effect on average feed intake. Both control and experimental groups lost body weight during the trials, but there was no significant differences in weight change between the groups. Leptaden-fed cows did not increase in milk production or change in the content of fat or total solids in their milk compared to the controls. Heart rates, respiratory rates, and rectal temperatures of all cows were within normal ranges in all periods. The serum protein-bound iodine and blood glucose indicated that Leptaden did not impair thyroid activities of the cows. No significant differences were noted in other health related data between the Leptaden-fed and control cows.

Each State is given specific responsibility to develop, coordinate and administer the Dairy Herd Improvement Program through a Memorandum of Understanding between the Cooperative Extension Service of the State, the Federal Extension Service and the Animal Science Research Division of the Agricul tural Research Service of the United States Department of Agriculture. The current 1V~emorandum became effective in July, 1969. In addition to stating the purposes and objectives of the program, the Memorandum also outlines the assigned responsibilities of all concerned. The major responsibilities of various groups are covered in this paper.

Spear, a high protein oat variety, was evaluated during 2 consecutive yr for yields of forage dry matter and for feeding value as a silage to heifers, steers, and lactating cows. In yr 1 and 2, Spear yielded 7% and 13% less forage dry matter per hectare than Burnett, a comparative oat variety. Crude protein contents in silages were similar for varieties both years. In yr 1, Holstein heifers fed high protein and medium protein oat silages gained the same amount of weight but less weight than heifers fed alfalfa-brome hay. In a total collection digestion trial with six lactating cows, digestibilities of Spear were less than Burnett oat silage or alfalfa-brome hay. In yr 2, Spear and Burnett silages were fed ad libitum without a concentrate mixture to seven Holstein heifers each. Average daily gains were higher with Spear than Burnett. Apparent digestibilities as determined with steers tended to be less for Spear than Burnett. Dry matter intakes, milk yield, and composition were similar in a switchback lactation trial with ten cows fed spear or Burnett in oat silage supplemented with a concentrate at 1 kg per 3 kg milk produced.