Digesta kinetics in sheep and cattle fed diets with different forage to concentrate ratios at high and low intakes.

Effect of maintenance and ad libitum intakes on digesta kinetics was studied with six ruminally fistulated cows and six ruminally fistulated wethers to validate the use of sheep as a model of cattle. Complete diets were made up of ratios of alfalfa:cracked corn and soybean meal of 80:20, 55:45, and 30:70. The rate of passage of Cr-mordanted alfalfa and soybean meal in the reticulorumen was negatively related to percentage of concentrate in the diet in both species at low intakes. Passage values of particulate and liquid markers were faster at high than at low intakes in both species for all diets. Rumen liquid volume increased with intake only in the cows on the low and intermediate concentrate diets. No substantial differences were found in particulate passage values between sheep and cattle. However, liquid passage rates from the rumen and the differentials between liquid and particulate dilution rates were higher in cows than in sheep for all diets at both intakes. These results together with those for digestibility data reported in a previous communication suggest that caution should be exercised when extrapolating results from one species to the other.

Overall efficacy of chronically administered recombinant bovine somatotropin to lactating dairy cows.

Recombinant bST at daily dosages of 0, 10.3, 20.6, and 41.2 mg/d were injected for 266 d into 8, 10, 9, and 9 Holstein cows, respectively. Treatment effects of recombinant bST were assessed for milk production traits, BW, blood components, and health and reproductive variables. Data reported compare controls to all bST-treated cows. There was an average increase of 18% in 3.5% FCM for bST versus control cows. This increase resulted in enhanced feed efficiency for bST cows, as their DM intakes were not elevated above those of the control cows. Recovery of BW was similar between control and bST groups. Milk composition was unaffected except for a slight decrease in protein percentage during the first 9 wk of treatment, and an elevated SCC between wk 19 and 28. Blood parameters were not different between control and bST cows, except for hematocrit, which decreased with bST treatment. The only health and reproductive parameters affected by bST were mastitis and days open, which were increased in the highest dosage groups.

Comparative digestion in sheep and cattle fed different forage to concentrate ratios at high and low intakes.

Effect of maintenance and ad libitum intakes on digestibility of different feed fractions was studied with six ruminally fistulated cows and six ruminally fistulated wethers to validate the use of sheep as a model for cattle. Complete diets were made up of ratios of alfalfa:cracked corn and soybean meal of 80:20, 55:45, and 30:70. The regression coefficient of the line relating organic matter digestibility with proportion of concentrate in the diet was smaller for the cows at ad libitum intake than for the other groups. Increasing the intake caused a decrease in digestibility of different fractions. The depression in digestibility was greater for the 30:70 forage:concentrate diet than for the others. At high intake, digestion values in the cows were less than those in the sheep for all diets. An increase in intake depressed the digestion of cell wall fractions and cell solubles including starch in cows, whereas in sheep, an increase in intake reduced cell wall digestion and to a lesser extent cell solubles, without affecting starch digestion. The digestive physiology of these species is sufficiently different to preclude the use of sheep data in formulating nutrient requirements for cows.

Response of dairy cows in early lactation to sodium hydroxide-treated soybean meal.

To determine effects of protein and rumen degradability in rations for early lactation cows, four diets (44:56 roughage:concentrate) were formulated to contain 15 or 17.5% CP and supplemental protein from untreated or NaOH-treated soybean meal. Diets were allocated to 34 multiparous Holstein cows from d 22 to 91 of lactation. Treatment means adjusted by covariance using data from d 10 to 21 for average daily milk (kg), milk fat (%), milk protein (%), and SCM (kg) were: 15% untreated 32.9, 3.54, 3.16, and 31.3; 15% NaOH-treated 31.1, 3.59, 3.08, and 29.6; 17.5% untreated 32.2, 3.70, 3.30, and 31.2; and 17.5% NaOH-treated 32.6, 3.58, 3.17, and 30.8. Increasing dietary protein percent raised milk protein percent but not protein yield or yield of other milk components, milk yield, SCM yield, or DM intake. Protein source had no effect on production or feed intake. Decreasing dietary protein percentage and use of NaOH-treated soybean meal reduced rumen ammonia. Degradation of protein in feeds was determined in four rumen fistulated lactating cows. Sodium hydroxide treatment of soybean meal reduced protein degradation in situ.

An attitudinal assessment of faculty practice plans.

An awareness of potential conflict between medical schools and private practice prompted an attitudinal assessment of faculty practice plans (FPPs). A representative sample of eight medical school FPPs in seven different communities was selected for study. For each FPP, a sample of health care leaders, stratified at different levels of administrative responsibility, was selected from academic medical centers and from community settings. Topics for FPP assessment were chosen for their relevance to physician and lay administrators involved with academic and community practice. Questions were answered on a yes-no basis and were graded by intensity of response. Although only two of the questions revealed statistical disparity on a simple yes-no basis, the intensity of response differed significantly in eight of the 14 questions asked. This study gives consideration to the strategic implications of FPPs for universities, medical schools, and organized medicine.

Effect of prepartum energy, body condition, and sodium bicarbonate on production of cows in early lactation.

In trial 1, the effects of dietary energy (102, 131 or 162% of requirement) in the dry period and of sodium bicarbonate (0 or .75% of diet dry matter) in early lactation were assessed with 31 cows in a 3 X 2 factorial arrangement of treatments. Body condition and weight increased linearly with prepartum energy. Dry matter intake and milk yield were similar across treatments through 12 wk postpartum. Sodium bicarbonate increased milk fat content only in the 131% group, an effect apparently related to greater mobilization of fat in that group. In trial 2, energy treatments imposed in late lactation (145 to 55 d prepartum) and in the dry period (55 to 0 d) were 1) cows fed to requirement in both periods, 2) cows overfed in the first and underfed in the second period, 3) cows fed to requirement in the first and overfed in the second period, and 4) cows overfed in both periods. Cows in treatments 1 and 2 (normal) calved in a thinner state than those in 3 or 4 (fat). In the first 12 wk postpartum, intake did not differ, but cows in groups 3 and 4 produced more milk. Sodium bicarbonate imposed factorially postpartum increased milk fat content. Overconsumption of energy prepartum did not impair production when high energy total mixed rations were fed postpartum.

Faculty practice plans. Profile and critique.

In 1910, the Flexner report signaled the end of commercialism in American medical schools, only to have it reappear in 1931. Between 1960 and 1985, access to federal, state, and private-sector funds paid to medical service plans in all 127 medical schools led to almost a 20-fold increase in faculty practice plan (FPPs)--from six to 118. All 127 US medical schools were surveyed. Wide swings in federal funding policies left medical schools with a defective management model, particularly for FPPs. Disposition of collected revenues, the role of for-profit FPPs, the personally lucrative nature of FPPs, an unwieldy number of fairly autonomous departments, ineffective governance, and hostile opposition from other parts of the university have raised questions of conflict of interest and accountability. Some 75 years after the Flexner report, a thorough evaluation of the effects of commercialism on medical education once again appears to be warranted.

Effect of varying protein and energy densities in complete rations fed to cows in first lactation.

Sixty-three Holstein cows in first lactation were allotted randomly at 28 days postpartum to receive one of nine rations in a 3 X 3 factorial design. Rations had crude protein 12, 15, or 18% in each of three energy densities from ratios of forage:concentrate of 75:25, 55:45, and 35:65. Corn silage and hay crop silage were combined in a ratio of 2:1 (dry basis) in each case, and diets were offered for ad libitum intake as complete feeds for an 11-wk experimental period plus 2 wk for a digestion trial. In regression analysis as energy density increased, feed intake, milk yield, milk protein, and lactose yields increased linearly, urea nitrogen in blood plasma decreased linearly, and milk fat percent and yield decreased curvilinearly. As dietary protein increased, feed intake, fat-corrected milk, milk fat yield, and plasma urea nitrogen increased linearly, and yields of milk, solids-corrected milk, milk protein, and lactose increased curvilinearly. Actual milk yield adjusted for dry matter intake increased with greater energy density but not with higher protein concentration. Increases of energy and protein each resulted in linear increases of digestibility of dry matter, crude protein, and energy of diets. There were no interactions of energy X protein for these measurements. Cows in first lactation will increase milk production in response to increasing protein over a range of energy densities when feed intake is increased.

Response of cows to a reduction in dietary crude protein from 17% to 13% during early lactation.

Four treatments involving 48 multiparous cows (12 per group) were compared during wk 0 to 19 postpartum. Treatments involved decreasing dietary crude protein from 17% to 13% at the 5th, 10th, or 15th wk postpartum or leaving on the 17% diet throughout. Treatment means across periods for milk yields, solids-corrected-milk, dry matter intake, crude protein intake, and milk fatty acids of chain length less than or equal to palmitoleic acid, adjusted by covariance, in orders listed were 27.4, 28.0, 29.1, 29.5 kg; 23.2, 25.1 26.4, 26.8 kg; 19.0, 19.7, 20.4, 20.6 kg; 2.65, 2.98, 3.31, 3.44 kg; 59.83, 63.72, 62.74, 64.55%. There were linear increased as duration on 17% diet increased. The effect of decreasing dietary protein percent was greatest for the change at 5 wk postpartum. Milk fat, protein, and lactose percentages were not affected by treatment. Protein disappearance from nylon bags inserted in rumen fistulated steers was more rapid on 17% than 13% crude protein rations, but ration dry matter disappearance did not differ between rations.