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Arterial and venous concentrations, extraction ratios and uptake of glucose, L-lactate and volatile fatty acids were measured in the hind half of four beef steers (340 to 360 kg) fitted with indwelling catheters in the posterior aorta and vena cava. The steers were fed hourly a pelleted, 85% concentrate diet. Treatments were control, iv infusion of insulin (1.4 IU/min) and iv infusion of glucose (149.4 mmol/h). Arterial blood concentration of glucose decreased from 3.23 mM (control) to 1.51 mM (insulin), then increased to 4.29 mM (glucose). Extraction ratio of glucose increased about threefold from 2.6 and of L-lactate decreased about fourfold from 9.2 during insulin infusion, then returned toward control values during glucose infusion. Extraction ratios of acetate (39), propionate (45) and butyrate (28) were similar among treatments. Uptake (two steers) of glucose from blood (mmol/h) increased from 38 (control) to 76 (insulin) and 99 (glucose). Uptake of acetate, propionate and butyrate from plasma (mmol/h) was, respectively, 105, 6.5, .93 (control); 170, 11.9, 3.53 (insulin) and 134, 10.9, 3.12 (glucose). Rates of uptake of glucose and propionate during control were slower (P<.05) than rates during insulin or glucose infusion; nonsignificant changes in uptake of butyrate followed a similar pattern. Uptake of L-lactate tended to be inversely related to uptake of glucose. Treatments did not affect uptake of acetate or valerate. Uptake of all metabolites except valerate was positive, indicating net use by the hind half.

A total of 88 purebred yearling Dorset, Hampshire, Suffolk and Targhee rams and ewes were randomized within breed and sex to 9.1 or 12.2 mg of cyclophosphamide (CPA) per pound of body weight (20.0 or 27.0 mg/kg). The drug was given once, in freshly prepared aqueous solution, by stomach tube. The objective was to determine whether these breeds differ in their defleecing response to CPA.The degree of wool loosening was assessed subjectively by a scoring system on days 6 and 8 after CPA treatment. The loosened wool was not manually removed, but was permitted to come off as it would in the course of the sheep's activities. The percentage of area from which wool had been lost from five contiguous locations on the body was estimated by visual inspection on day 13 after CPA treatment, and wool regrowth was measured on the shoulder 39 days after CPA treatment.The response to CA was affected by sex, CPA dosage, the particular location of the wool on the sheep and days after CPA treatment in a manner generally similar to previous observations, but no differences were observed among the four breeds that would require a different management system for chemical defleecing for one breed relative to any of the others.

Twenty-seven 4- to 6-month-old crossbred ewe and ram lambs were assigned at random within sex to dosages of 10, 20 or 30 mg of cyclophosphamide (CPA), a chemical defleecing agent, per kilogram of body weight. Erythrocyte and plasma acetylcholinesterase (AChE) activities were measured in jugular blood before CPA treatment and 1, 5, 9, 13, 17, 21 and 26 days thereafter. As in man, both plasma and erythrocyte AChE activities were depressed following CPA treatment, reaching their lowest levels on days 9 and 1, respectively. No physical signs of depressed AChE activity were observed in any of the sheep. The depression of neither the plasma or the erythrocyte enzyme can be used presumptively to identify sheep that have been treated with CPA before that fact is evident from the woold itself.

Three pairs of mature, dry, nonpregnant Holstein cows were fed at maintenance diets of 80:20, 50:50 or 20:80 hay (chopped timothy) to concentrate (82% corn meal, 15% soybean meal, 3% limestone) and, using a balanced switchback design, were either infused via fistula or not with acetic acid to supply the equivalent of an additional 10% of maintenance. The infusate was delivered at a constant rate in 2 liters of aqueous solution over 20 hr per day by way of a stainless steel device that assured its delivery into the ventral rumen 4 to 6 cm from the mucosa. Apparent digestibilities of dry matter, organic matter, gross energy acid detergent fiber, nitrogen and nitrogen retention were unaffected by the acetic acid infusion. Neutral detergent fiber, cellulose and hemicellulose digestibilities were reduced by acetic acid infusion at 20:80 hay to concentrate ratio, but were unaffected at rations of 80:20 or 50:50. In rumen fluid, acetic acid concentration was increased and pH was reduced by the acetic acid infusion at all hay to concentrate ratios. Osmolarity, sodium and potassium concentrations were unaffected by acetic acid infusion. Concentration of propionate, i-butyrate, i- and n-valerate, but not n-butyrate, was reduced by acetic acid infusion. Over a feeding cycle from 7.00 am to 5:00 pm, acetic acid infusion did not affect the postprandial rise in concentration of any of the volatile fatty acids or total volatile fatty acids, the reduction in pH, or potassium concentration. Osmolarity and sodium concentration were unaffected by time over the feeding cycle or by acetic acid infusion. These results are discussed in relation to the use of intraruminal infusion of acetic acid to measure its partial efficiency for body tissue deposition in cattle.

Grade Hampshire rams were fed for 11 months ground, pelleted alfalfa hay to which had been added no insecticide, methoxychlor at 200 or 1,000 ppm or malathion at 270 or 1,350 ppm. Average levels of insecticide in the spiked feeds, by analysis, were for methoxychlor, 178 and 873 ppm and for malathion 192 and 941 ppm, respectively. Semen characteristics and spermatozoan morphology were assessed at 0, 3, 6 and 11 months of treatment. Except for an apparent increase in the percentage of dead, tailless spermatozoa in rams receiving the higher level of methoxychlor, the biological significance of which is unknown, no effects of pesticide ingestion were observed.

More salt (offered ad libitum) and more water were consumed and more urine voided on pelleted than on ground alfalfa hay. The greater intake of both salt and water were attributable to form of forage per seand were independent of one another.Over a range of pelleted alfalfa intake from about maintenance to ad libitumintake, water intake was much more closely related to forage than to salt intake. The partitioning of water loss between urinary and other routes of disposal was much affected by level of forage intake; evaporative and fecal loss became more important, and urinary less so, as forage intake increased.The appetite for salt offered free choice decreased as the level of forage intake was increased to ad libitumintake. All levels of salt intake were much above requirements, and this result was considered more closely related to appetitence generally than to a physiological need for sodium or chloride.At levels of salt intake which did not exceed ad libitumintake, water intake and urine output were not related to salt consumption.Levels of salt eaten ad libitumby sheep depends to a degree on the level to which they have become accustomed. Appreciable individual differences in salt and water intake exist among individual sheep that are homogenous as to breed, sex, age and previous treatment. These individual differences in salt and water intakes, however, do not appear to be closely correlated.

Mature rams and ewes treated with 15, 20 or 30 mg of cyclophosphamide (CPA) per kilogram of body weight were observed over the period after the wool loosened and could have been removed until the regrowth of wool appeared. The wool, however, was not removed, but was allowed to come off as it would. The percentage of area from which wool had been lost was estimated on the head, neck and brisket, the shoulder, the side, the hip and the belly on days 16, 21 and 28 after treatment. These areas were contiguous and covered the whole wooled surface of the sheep. Wool regrowth was scored on the shoulder on days 16, 21, 28 and 32 after treatment.The retention of the fleece over time was greater with decreasing CPA dosage. Also, appearance and rate of regrowth increased with decreasing dosage. These results are discussed in terms of the known action of cydophosphamide and also in terms of the practical management of a chemical defleecing operation.

In terms of its biochemical mechanism, the action of cyclophosphamide (CPA) as a defleecing agent is unknown. Its effects on the wool fiber, however, are understood (Dolnick et al., 1969). The individual wool fibers are constricted under the influence of the drug. Thereafter, the growth of the fiber carries the constriction toward the skin surface, and fibers break, or can be broken, at the point of constriction.The objective of the study was to determine whether the rate of wool loosening is “all or none”, i.e., independent of CPA dosage, or whether the response is dose dependent.Seventeen ewes and five rams were randomized within breed and sex to each of three groups. The distribution of breeds within groups and within sex is shown in table 1. All of the sheep were 2 years old or older. All had been conventionally shorn 27 weeks previously. None had ever before received CPA.