Squeeze Chute Research Articles

Exploratory Trial to Determine the Efficacy of Yt-1C10B Pour-on for the Control of Lice Infesting Cattle, 1994

Abstract The experiment was performed at the Waggoner Ranch, Laramie, Wyoming. Experimental animals were commercial cattle of mixed breeds born in the spring of 1993. Cattle were housed in 4 separate pens at the rate of 5 animals per pen. Each pen was approximately 20 X 60 ft. Cattle were fed at the rate of 2 lbs of corn per animal per d, plus free choice alfalfa/grass hay. Salt, mineral mix, and well water were provided ad libitum. Efficacy was determined by counting all species of lice present on the animals. Lice infestations were naturally acquired. At the time of the pretreatment counts (8, 9 Mar) all cattle were infested with Linognathus vituli, 18 were infested with Bovicola bovis and two were infested with Haematopinus eurysternus. Treatments were applied, following pretreatment lice counts on 9 Mar 1994. Post treatment counts were performed 6, 14, 21, 28, 35, 42, 49 and 56 DAT. For purposes of examination, cattle were restrained in a squeeze chute with a head catch. A high intensity lamp provided illumination. Lice were counted in eight examination sites on each animal. Examination sites and dimensions were as follows: topline 5 X 15 cm, withers 5X15 cm, around right eye 10 X 15 cm, around left eye 10 X 15 cm, right cheek 5 X 10 cm, left cheek 5 X 10 cm, muzzle 5 X 25 cm and dewlap 5X15 cm. Sample sites included predilection areas of L. vituli, B. bovis, and H. eurysternus. Following pretreatment lice counts, all animals were ranked by total counts of L. vituli. The two animals with the highest counts were randomly assigned to either replicate 1 or 2. The next two animals were then assigned to the other replicate. This procedure was repeated with each group of 4 similarly infested animals. Treatment was randomly assigned to each animal within a pair of similarly infested animals. Treatment was based on body wt: 15 ml per animal 750 lb or greater; 10 ml per animal 500 to 750 lb; and 5 ml per animal 250 to 500 lb. The cattle weighed between 302 and 846 lb. Insecticide was applied as a pour-on from a graduated container along the face, neck, shoulder and midline of each animal as far back as the dosage would allow. Total lice counts were transformed using In (total count + 1). A general linear model procedure (SAS) was used to analyze the transformed counts. Total variation in the lice count was partitioned into that attributable to the treatment, animal within treatment, sampling d, treatment X sampling d interaction, and residual. Geometric means for lice counts were estimated for each treatment group on each sampling d.

Cattle with hair whorl patterns above the eyes are more behaviorally agitated during restraint

Hair whorl position on the forehead may be of value in selecting breeding cattle for a calm temperament. A total of 1500 cattle weighing 180–360 kg were temperament rated on a four-point scale. Seventy-two percent of the cattle were European × British breed crosses and 28% were Zebu × dairy breed crosses from Mexico. Cattle with a round hair whorl located above the eyes became significantly more agitated while they were restrained in a squeeze chute (crush) compared to cattle with a hair whorl located either between the eyes or below the eyes. For both the Bos taurus and Bos indicus crossbreeds, animals with hair whorls located below the eyes were rated calmer. There is a positive linear relationship ( P < 0.001) between cattle temperament while restrained in a squeeze chute and the location of facial hair whorls. The cattle observed in this study were extensively raised and had a large flight zone when approached by people. Casual observations indicate that the relationship between hair whorl position and temperament is most easily observed in cattle that do not have daily close contact with people.

Methods for reducing stress during transport and handling

Stress can be reduced during transport and handling by training people to use behavioral principles when handling animals, selecting livestock with a calm temperament and using well designed handling facilities and vehicles. In the U.S., there are increasing problems with very excitable cattle and pigs which are very difficult to handle and drive. Gentle, quiet handling of excitable genetic lines of pigs in single file races in a high speed slaughter plant is extremely difficult. Excitable pigs are more easily distracted by small distractions such as a sparkling reflection on the floor and are more likely to balk and pile up. Some excitable genetic lines of pigs have greatly elevated death losses during transport. Excitable animals are more fearful of novel new situations than calmer genetic lines. Similar excitability problems are being observed in cattle. Excitable genetic lines of cattle are more likely to severely injure themselves or handlers during handling because they are more likely to panic when confronted with novelty. The author has observed cattle from excitable genetic lines that went into a total panic when they were in novel surroundings. Excitability problems are more likely to cause problems in the U.S. due to very extensive raising of cattle. Excitable cattle that are reared intensively become accustomed to people and vehicles and they are more tolerant of novel situations than excitable cattle reared on open rangeland where they seldom see people. Excitable genetic lines of cattle which are completely halter broken become trained to accept novelty and will usually remain calm, but when these same animals are raised extensively where they seldom see people, they often panic and injure themselves when they are brought to an auction market or slaughter plant. Breeders need to select animals that have a calm temperament. Recent research in our laboratory has shown that the position of the spiral hair whorls on the foreheads of beef cattle is related to temperament. Beef cattle with high hair whorls located above the eyes become more agitated during restraint in a squeeze chute compared to cattle with hair whorls located between or below the eyes. Indiscriminant selection for rapid growth and leanness has contributed to this problem. Excitable genetic lines of cattle and pigs are causing serious welfare problems during handling in the U.S.

Methods for reducing stress during transport and handling

Stress can be reduced during transport and handling by training people to use behavioral principles when handling animals, selecting livestock with a calm temperament and using well designed handling facilities and vehicles. In the U.S., there are increasing problems with very excitable cattle and pigs which are very difficult to handle and drive. Gentle, quiet handling of excitable genetic lines of pigs in single file races in a high speed slaughter plant is extremely difficult. Excitable pigs are more easily distracted by small distractions such as a sparkling reflection on the floor and are more likely to balk and pile up. Some excitable genetic lines of pigs have greatly elevated death losses during transport. Excitable animals are more fearful of novel new situations than calmer genetic lines. Similar excitability problems are being observed in cattle. Excitable genetic lines of cattle are more likely to severely injure themselves or handlers during handling because they are more likely to panic when confronted with novelty. The author has observed cattle from excitable genetic lines that went into a total panic when they were in novel surroundings. Excitability problems are more likely to cause problems in the U.S. due to very extensive raising of cattle. Excitable cattle that are reared intensively become accustomed to people and vehicles and they are more tolerant of novel situations than excitable cattle reared on open rangeland where they seldom see people. Excitable genetic lines of cattle which are completely halter broken become trained to accept novelty and will usually remain calm, but when these same animals are raised extensively where they seldom see people, they often panic and injure themselves when they are brought to an auction market or slaughter plant. Breeders need to select animals that have a calm temperament. Recent research in our laboratory has shown that the position of the spiral hair whorls on the foreheads of beef cattle is related to temperament. Beef cattle with high hair whorls located above the eyes become more agitated during restraint in a squeeze chute compared to cattle with hair whorls located between or below the eyes. Indiscriminant selection for rapid growth and leanness has contributed to this problem. Excitable genetic lines of cattle and pigs are causing serious welfare problems during handling in the U.S.

The reluctance of cattle to change a learned choice may confound preference tests

Choice testing utilizing a Y-maze has been successfully used to test animal preferences. In this experiment, 12 female Angus×Hereford×Simmental×Charolais heifers were given a choice of walking through a squeeze chute (crush) or being restrained in a squeeze chute. The objective of the study was to determine if previously learned choices in a Y-maze would confound future choices. A start box led to two races in a Y configuration. There was a hydraulic squeeze chute at the end of each race. Animals that chose the right side were allowed to walk through the squeeze chute and animals that chose the left side were restrained in the squeeze chute for 30 s. During eight choice trials, the heifers had a definite preference for the ‘walk’ side. There were 64 walk choices and 32 ‘restraint’ choices. For six additional trials, the restraint and walk sides were switched. Walk choices dropped to 16 and restraint choices rose to 56. The resistance to switching effect was significant ( P<0.01). Significantly more heifers vacillated (looked back and forth) at the decisionpoint after the sides were switched ( P<0.01). The switch had been perceived by the animals. There is a tendency for cattle to resist changing a choice once they are accustomed to a treatment being associated with a specific side.

Determination of early pregnancy in ewes utilizing transrectal ultrasonography

Transrectal ultrasonography was used in ewes to determine the earliest day at which pregnancy could be detected, the number of embryos present, and the pattern of growth of the embryos. Twenty-one ewes were placed with 2 fertile rams and 20 ewes with 2 vasectomized rams. All ewes were treated to synchronize estrus and were observed for estrus twice daily. The 36 ewes that showed synchronized estrus were separated from the rams following mating. Transrectal ultrasonography was performed daily from estrus (Day 0) to Day 25 for all ewes and on Days 30, 35 and 40 post breeding for the 20 ewes mated to fertile rams. A 7.5 MHz transducer (human prostate, linear array) was utilized, with the ewes in dorsal recumbency in a tilting squeeze chute. Extraembryonic fluid and membranes were observed in the uterine horns ipsilateral to corpora lutea by Day 15 post breeding in all 17 ewes subsequently diagnosed as pregnant. Rhythmic pulsations (heartbeat) within the embryonic vesicles were first detected on Day 18 or 19. At least 1 embryo was detected by Day 20 in all the pregnant ewes, but not all the embryos were counted accurately until Day 25 (main effect of day; P < 0.05). Two ewes each had an embryo which died (absence of previously observed heartbeat) by Day 25 or Day 40, respectively, but each maintained the remaining embryos to term. The pattern of embryonic growth, as determined by crown-rump lengths on Days 20, 25, 30, 35 and 40, did not differ with the number of embryos carried (n = 1 to 4). In conclusion, transrectal ultrasonography was found to provide a rapid, accurate means for the early detection of pregnancy in ewes.

Behavioral agitation during handling of cattle is persistent over time

Cattle which become extremely behaviorally agitated during restraint and handling are dangerous to handlers and are more likely to become stressed. Fifty-three Gelbvich×Simmental×Charolais cross bulls and 102 steers were restrained for blood testing every 30 days in a squeeze chute (crush). At the same time they were also weighed in a single animal scale. Out of four consecutive restraint sessions. five (9%) of the bulls became extremely behaviorally agitated every time they were restrained. During three consecutive restraint sessions, six (6%) of the steers were always behaviorally agitated. Of the bulls, 13 (25%) were very calm and stood still in the squeeze chute. Of the steers. 40 (40%) were always very calm. The implications of the study are that behaviorally agitated behavior is very persistent over a series of handling and restraint sessions, and cattle which repeatedly become agitated during restraint should be culled. There was also a relationship between balking and temperament rating. Agitated bulls balked less during entry into the squeeze chute or scale. Cattle also balked less while entering the scale. This indicates that restraint in the squeeze chute was more aversive than the scale.

Novel breeding box has variable effects on heart rate and cortisol response of cattle

In seven experiments, cattle of different sex classes (bulls, steers, and cows), age (2–10 years), and breed (Augus, Hereford, and Braford) were subjected, one at a time, to restraint by a standard squeeze chute (cattle crush) or a novel ‘breeding box’ in order to compare each method's effects on heart rate and cortisol. The breeding box held two cattle in adjacent stalls and was covered with plywood to limit outside disturbances and light. The cattle were held in either the squeeze chute or the breeding box for 3 min while five heart rate samples were recorded at 0.5, 1, 1.5, 2, and 2.5 min after entering the treatment; in four of the experiments, one tail vein blood sample was taken at 3 min for plasma cortisol analysis. In one of the experiments, heart rate responses were greater for the chute restrained cows than for the cows restrained in the breeding box ( P<0.04). In a second experiment, cortisol response was also greater ( P<0.03) for the chute restrained cows than for the cows restrained in the breeding box. No differences were found for cortisol and heart rate responses in the other five experiments. Because breed, sex, and age were consistent between four of the experiments, data were combined and the results indicate that mean plasma cortisol concentrations were greater for the squeeze chute treatment than for the breeding box ( P<0.01), but no differences were found for heart rate. Angus cattle tended to have greater mean plasma cortisol concentrations than Hereford cattle for the combined experiments ( P<0.07). The Angus cattle also had greater heart rates than the Hereford cattle in one experiment ( P<0.05). The results from this research indicate that restraining cattle in a breeding box that was novel to them was as stressful as being restrained in a squeeze chute in which they had been subjected to routine production procedures. The stress resulting from being restrained in a novel breeding box when cattle are artificially bred may contribute to the variable conception rates reported by ranchers.

Performance and health of weanling bulls after butorphanol and xylazine administration at castration.

A total of 268 crossbred, 6- to 9-mo-old, bull calves (214 +/- 19 kg) were used in two separate 27-d experiments to assess the effects of butorphanol and xylazine administration (BXA) on the subsequent performance and health of beef calves. In each experiment, calves were randomly allotted to four treatment groups: 1) castration with BXA, 2) castration without BXA, 3) no castration with BXA, and 4) no castration without BXA. There were two replicates within each experiment. The intravenous administration of .07 mg/kg of butorphanol and .02 mg/kg of xylazine occurred 90 s before tail hold and castration procedures. Calves were placed in a squeeze chute and manually restrained by tail elevation. In Exp. 2, the cattle also were scored for chute activity (on a 1 to 5 scale with 5 being the most active). Cattle were weighed at the beginning and end of the experiment, feed intake was recorded daily, and cattle were monitored daily for respiratory disease. There were no castration x BXA interactions (P greater than .51). Castration reduced (P less than .01) daily gain and gain/feed and tended (P = .13) to reduce feed intake. The administration of BXA had no effect (P greater than .05) on gain or gain/feed but did tend (P = .13) to reduce feed intake. No differences (P greater than .45) were observed in morbidity or mortality due to either BXA or castration. Castration and BXA increased (P less than .01) blood cortisol levels on d 3, whereas control animals had reduced cortisol levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of freeze or hot-iron branding of angus calves on some physiological and behavioral indicators of stress

Twenty-four Angus calves averaging 293 ± 38 kg were either hot-iron branded (H), freeze branded (F), or served as a sham (S). Calves were blocked for temperament, weight, and sex, and randomly assigned to day and order in which treatments were applied. To reduce stress from handling at treatment time, each calf was herded through the squeeze chute for 5 days prior to the experiment. Jugular cannulae were established in each calf 1 day prior to application of treatment. Blood samples and heart rate were obtained at −5 and −3 min prior to and 0, 0.5, 1, 3, 5, 10, 15 and 20 min after calves were branded on the hip. Mean plasma cortisol concentration increased for all treatments during the sampling times ( P = 0.0001). Mean plasma epinephrine concentration was greater ( P < 0.01) for H calves at 0.5 min after branding than either S or F calves. Hot-iron branded calves had greater ( P < 0.02) mean heart rate during branding and 30 s post-branding than did either S or F calves. The escape-avoidance reaction of H calves, quantified as the amount of vertical movement the calf exhibited during branding, was also greater ( P < 0.05) than either the F or S calves. Five H calves, four F calves, and no S calves vocalized during treatment. The greater escape-avoidance reaction as well as the elevated heart rate and plasma epinephrine concentration of the H calves indicate that a greater pain sensation is perceived by hot-iron branded Angus cattle.

Behavioral and physiological effects of freeze or hot-iron branding on crossbred cattle.

Twenty-seven crossbred calves (1/2 Simmental, 1/4 Hereford, 1/4 Brahman) averaging 257 +/- 11 d of age were either hot-iron-branded (H), freeze-branded (F), or sham-branded (S). Calves were blocked for temperament, weight, and sex and were randomly assigned to day and order in which treatments were applied. To reduce stress from handling at treatment time, each calf was herded through the squeeze chute daily for 5 d before the experiment. Jugular cannulas were inserted in each calf 1 d before application of treatment. Blood samples and heart rate measures were obtained at -5, -3, 0, .5, 1, 3, 5, 10, 15, and 20 min after application of the treatments. Mean concentrations of plasma epinephrine (EPI) were higher for H calves at time .5 min than for either S or F calves (P = .10). To account for individual differences, prebranding heart rates and hormone concentrations were subtracted from subsequent samples and were also used to calculate a proportion for each subsequent sample. Analyses of subtracted values found that EPI concentrations were greater for H calves than for either S or F calves (P = .007) at .5 min postbranding. No other differences were found for the subtracted analyses. Analyses of proportion data also revealed that H calves had greater EPI than did either S or F calves (P = .027) at .5 min postbranding. Only three animals vocalized during branding, one H calf and two F calves. Despite the 5-d acclimation period, handling and restraint elevated plasma cortisol concentrations and heart rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of naltrexone on relaxation induced by flank pressure in pigs

Twenty, 6 to 9 kg Yorkshire piglets were used in 2 trials. Ten piglets received an IM injection of naltrexone at a dose of 1 to 1.3 mg/kg. Ten control pigs received saline. Blind behavioral testing in a “squeeze chute” was conducted 40 minutes after injection. The “squeeze chute” consists of two padded plywood panels hinged on a base to form a V. Each pig was squeezed for 60 seconds. After release, eahh pig remained in the padded V for 10 minutes. There was sufficient room for the pigs to walk a few steps. Both naltrexone- and saline-treated pigs eventually crouched down in the chute and relaxed against the padded sites of the V. Naltrexone-pretreated pigs had a longer latency to achieve relaxation—311.8±47.8 seconds vs. 161.8±30.38 seconds (SE) ( p<0.02). Each stage of relaxation at induction was rated on a 1–4 scale (1 = squealing and jumping, 4 = relaxed quietly). Naltrexone-treated pigs had significantly lower relaxation ratings than saline-treated pigs (1.90 vs. 3.20) ( p<0.01). Treatment had no effect on the final degree of relaxation. Naltrexone partially blocked the relaxation response.

Effect of blood sampling and shipment to slaughter on plasma catecholamine concentrations in bulls.

The effect of venipuncture on blood serum catecholamine concentrations was studied in five yearling Red Angus bulls. Treatments consisted of sampling jugular vein blood via indwelling cannulas in a squeeze chute every 10 min for 1 h; sampling jugular vein blood from an indwelling catheter before, during and after venipuncture simulation; sampling jugular vein blood by venipuncture in a chute after shipment of 320 km to a slaughter plant; and sampling pooled blood from the neck during exsanguination at slaughter. Plasma epinephrine (E) and norepinephrine (NE) concentrations were determined by high performance liquid chromatography (HPLC) with electrochemical detection (ECD). Prevenipuncture NE and E in blood sampled from an indwelling catheter extended through a solid wall were 1.0 and .5 pmol/ml plasma, respectively. Plasma NE and E during venipuncture (1.6 and 1.1 pmol/ml, respectively) and immediately after cannulation in a squeeze chute (1.8 and 1.2 pmol/ml, respectively) were higher than prevenipuncture concentrations. Plasma NE and E, 1.9 and 1.2 pmol/ml plasma after shipment of 320 km, increased during exsanguination to 135.8 and 81.3 pmol/ml plasma, respectively. The NE and E in blood samples collected by venipuncture in a chute or box stall do not represent resting concentrations of these catecholamines.

Images of America: Travelers from Abroad in the New World by Robert B. Downs

Reviews 77 I See by My Get-Up. By Ron Querry. (Albuquerque: University of New Mexico Press, 1987. 151 pages, $19.95/$11.95.) On the literal level, Ron Querry tells the story of his metamorphosis from English teacher at the University of Oklahoma to cattle baron in New Mexico, to writer in Taos. Allegorically, the narrative celebrates fortitude, patience, and rashness as it interweaves the scenarios of the drifting cowboy who helps to save the ranch, of the tenderfootwho acquireswestern arete, and of the cow­ boywho is socompetent that he can stop being a cowboy—theVirginian motif. Morally, the tale recounts the way in which Querry is able to reconcile, in the process of writing the book, his desire to be a good old boy with his desire to use the academic training which the “real people” regard as womanly. The narrative is a bit weak anagogically, but characters and events are vividly and, as far as my experience reaches, accurately presented. The accounts of the Department Chair at the chili cook-off and of the first meeting of tenderfoot, bull, and squeeze chute do not depend on prior knowledge of the characters—I know the Chair but not Retardo Mountalbull, the two char­ acters least steady on their legs in this otherwise decorous narrative—but they are equally funny. Querry also has a real feeling for the landscape, people, and fauna of eastern New Mexico, and he conveys the passing of a generation whose legacy has been despoiled and abandoned by suburbanites for whom the West has become a picturesque diversion. The style exhibits the strengths (wryness of tone, vernacular rhythm, comic inflation) and weaknesses (vocabulary strained to archness, pseudo-oral padding, mock-self-deprecatory parentheses of southwestern humor.) More damagingly, this mode restricts Querry to stereotyped character and to anec­ dote, so that he is unable to make connections between events and their contexts. If Querry uses his own voice more consistently,' if he abandons the per­ sona of good old boy; and if he learns to trust his material and his reader— then in future work he can do more than entertain: he can tell us some important things about himself, about the West, and about those who read and enjoy his work. ROBERT MURRAY DAVIS University of Oklahoma Images of America: Travelers from Abroad in the New World. By Robert B. Downs. (Urbana and Chicago: University of Illinois Press, 1987. 232 pages, $24.95.) In a career that extends over more than half a century, the author of this volume has contributed prolifically to the literature of American librarianship 78 Western American Literature and bibliography. During the past three decades Robert B. Downs has also successfully addressed a nonspecialist reading audience as a scholar-bookman, summarizing and commenting on groups of “great books” in Western culture —west, that is, of China. His Books that Changed the World (1956) is a classic of the genre. Images of America, Downs’s most recent offering, is a seasoned perform­ ance in the latter line. Here he introduces us to forty works, issued between 1770 and 1944, all describing parts of America as seen by foreign travelers. Following a general introduction, he devotes one chapter to each of the titles under review. The reports of “standard” visitors like Mrs. Trollope, Dickens, and Stevenson all receive treatment, but Downs makes productive forays into less familiar territory. His accounts of independent visits to the United States in 1857 by a Japanese, Yukichi Fukuzawa, and a Russian, Aleksandr Lakier, are especially recommended. Downs’s claims for Images of America as a work of scholarship are mod­ est. His research, cited in the bibliographical notes, is not extensive. His book contains no footnotes, nor do page-references accompany his quotations. His practice of allotting on average about 1250 words to each author necessitates painful omissions and unsatisfying summary comments. Of course, Downs does not pretend to be encyclopedic or definitive. Instead, he offers a pleasant, well chosen, intelligently edited sampler. As he moves from author to author he agreeably varies the mix of biographical background, summary, and quota­ tion. (Henry Nevinson’s Good-bye, America! [1922] is represented almost entirely by a single...

The effect of the beef recipient female on embryo transplant offspring

Embryo transfer techniques were employed to investigate the importance of prenatal and postnatal maternal breed effects on calves of high growth potential (Chianina) and low growth potential (Angus). Six crossbred cow breed groups of known producing ability were used as recipients. These crossbred recipient females had been produced by artificia ly inseminating Angus and Hereford cows with semen from Chianina, Maine Anjou and Simmental bulls. Prior production records on the recipients cipients were used to calculate Most Probable Producing Ability (MPPA) estimates for each cow for birth weight and weaning weight. Donor breed differences were evaluated (P<0.01 to P<0.001) for all growth traits with Chianina calves having longer gestation lengths, heavier weights at all ages and greater hip heights than Angus calves. Chianina calves also were found to be more aggressive than Angus calves as determined by their higher scores (P<0.001) when entering the working chute and while restrained in the squeeze chute. Differences among the six crossbred recipient dam groups were not significant for any growth trait. From linear contrasts it was noted that Angus crossbred dams produced heavier calves at birth (P<0.005) and weaning (P<0.10) than Hereford crosses. When recipient females were grouped into quartiles based on MPPA estimates, no differences were detected among MPPA groups for either birth weight or weaning weight of their embryo transfer calves. Information to date from the present study suggests that the bovine recipient female has less influence on the performance of embryo transfer calves than would be anticipated based on earlier breed comparison studies. Apparently, if recipient cows from breeds that are reasonably similar in milking ability and mature size are used in an embryo transfer program, the maternal environmental differences are not great enough to prevent the transplant calves from expressing their growth potential. Crossnursing may also occur, so that transplant offspring with higher growth potentials may obtain enough milk from other dams to allow them to express their genetic potential. The potential milk producing ability of the beef recipient should still remain as a primary consideration by those involved in the transplantation of bovine embryos.

Feeder Cattle Stress During Handling and Transportation

ABSTRACT THE relationship between heart rate and stressor events which normally occur in the handling and transportation of feeder calves from producer to feedlot was determined. Heart rate was monitored with a bio-medical telemetry system and activity was monitored with a closed-circuit television system. In a laboratory ex-periment, three pairs of calves were subjected to various planned and ad lib stressor events such as placing in a squeeze chute, loading on a transport vehicle, and eating or drinking. The average heart rate increased by less than 10 beats/min (BPM) for mild stressor events such as gentle butting to more than 30 BPM for severe stressor events such as loading on a vehicle. A mathematical model was developed to predict the heart rate for various stressor events. In two other experiments, eight feeder calves from each of two truckloads were monitored during assembly, simulated auction sale, and while in transit (1600 km) from the producing area to the feedlot. These experi-ments showed that there was a significant difference in the stress, as measured by increased heart rate, between the two shipments. Much of the difference was attribut-able to differences in procedures and facilities. For ex-ample, efficient sorting of animals resulted in an increase of only 7 BPM while inefficient sorting resulted in an in-crease of 48 BPM. Heart rate appears to be related to stress and, therefore, may provide a fast objective way to measure stress and its effect upon subsequent animal health. Future research is planned to test this hypothesis as well as provide the information needed to develop more efficient handling and transportation procedures.

Advantages of the Kimberly-Rupp Instrument in Spaying Heifers

I started using the Kimberly-Rupp technique this year. I found it very advantageous in my practice which is small. Several reasons preparation time on these heifers where in many cases I don't have a squeeze chute, or we have to drag one in from somewhere, is none. We cut them off feed and water for twenty-four hours and preferably 36 hours. There's no clipping to do, and no scrubbing. We just run them in when we are ready to work, and that's that. Just a head catch cenainly works very adequately for doing this technique.

Observations of cattle behavior applied to the design of cattle-handling facilities

Field observations were conducted while cattle were being handled in abattoirs, auction markets, yards on ranches, dipping vats and restraining chutes. Mature cattle and calves of many different breeds were observed under commercial conditions. A review of the literature and the observations indicated that cattle can be most efficiently handled in yards and races which have long narrow diagonal pens on a 60° angle. In yards designed by the author, cattle which are waiting to be sorted are held in a 3–3.5 m-wide curved race with an inside radius of 7.5–11 m. From the curved race, the animals can either be sorted into the diagonal pens, or they can be directed to the squeeze chute, dipping vat, or restraining chute at the abattoir. The handler works from a catwalk which is located along the inner radius of the race. This facilitates the movement of the animals because they will tend to circle around the handler in order to maintain visual contact. The curved holding race terminates in a round crowding pen which leads to a curved single file race. Cattle have 360° panoramic vision and poor depth perception. Sharp contrasts of light and dark should be avoided. Single file races, forcing pens, and other areas where cattle are crowded should have high solid fences. This prevents the animals from observing people, vehicles, and other distracting objects outside the facility.

Winter Pregnancy Rates and Subsequent Fall Cow/Calf Ratios in Elk

Free-ranging elk (Cervus canadensis) wintering at the Hardware Ranch Game Management Unit near Logan, Utah were diagnosed for pregnancy by rectal palpation. Anatomical changes in gravid and nongravid uteri of cattle were found directly applicable to elk. Correlations between winter pregnancy rates and subsequent fall cow/calf ratios indicated that pregnancy checks would give wildlife managers a sixto eight-month forecast of an elk herd's productivity, assuming preand postpuberal losses remained constant. J. WILDL. MANAGE. 38(4):789-791 Intensified elk management programs require detailed reproductive information to provide a knowledgeable basis for herd manipulations. Available information on various species demonstrates that reproductive processes vary from one population to another, as variables such as climate, weather, and forage change. Rectal palpation generally is accepted to be the most reliable method of detecting pregnancies in bovine, particularly in the early and midgestational periods (Arthur 1964). Greer and Hawkins (1967) first reported the rectal approach for pregnancy determinations in elk. Fig. 1 shows the close correlation between fetal sizes of elk and cattle. It indicates similar fetal growth curves for these two species. METHODS AND MATERIALS The Cache elk herd and the Hardware Ranch Game Management Unit near Logan, Utah provide excellent opportunities to study reproductive parameters. In cooperation with the Utah Division of Wildlife Resources, free-ranging elk were trapped on the winter feed grounds at the Ranch and cows aged as mature or yearling (Hancock and Low 1956) were examined for pregnancy by rectal palpation during the 196970, 1970-71, and 1971-72 winters. A plastic arm-length glove was used to protect the hand and arm. After the elk were properly restrained in a Powder River squeeze chute, the gloved hand was lubricated and inserted into the rectum. Internal organs were contacted; the genitalia palpated, and the animal's reproductive status recorded. Similarities between cattle and elk uterine and ovarian locations and structure, as well as the senior author's previous experience with cattle, increased the efficiency of elk palpation. RESULTS AND CONCLUSIONS Nineteen adult and 5 yearling elk were trapped and rectally palpated during the 1969-70 winter, 60 adults and 23 yearlings in 1970-71, and 39 adults and 13 yearlings in 1971-72 (Table 1). There were no significant differences between the pregnancy rates observed during the 3-year study when statistically tested by chi-square. It is assumed that representative samples were taken and no preor postpuberal losses 1 A contribution of the Utah Cooperative Wildlife Research Unit, Utah State University, Utah Division of Wildlife Resources, U. S. Fish and Wildlife Service, and the Wildlife Management Institute, cooperating. 2 Present address: Ralston Purina Company, Checkerboard Square, St. Louis, Missouri 63199. J. Wildl. Manage. 38 (4):1974 789 This content downloaded from 157.55.39.149 on Sat, 09 Jul 2016 06:59:36 UTC All use subject to http://about.jstor.org/terms 790 WINTER PREGNANCY RATES IN ELK o Follis and Spillett

Nest Building in the Bengalese Finch. I : External Factors Affecting It and Its Relation To Other Behaviour Early in the Breeding Cycle

Pairs of Bengalese finches taken direct from stock cages in which the sexes are kept separately vary widely in the time taken to settle down. Birds showing a longer delay until they are prepared to incubate, also spend less time in the nest box soon after pairing and are seen to copulate later. Growth of interest in the nest box after pairing is slowed down when no nest material is provided. The peak period of building in normal pairs occurs in the five or six days prior to the first egg. The female does the majority of building within the nest box; the male does by far the majority of carrying of nest material to it. In normal pairs nest building declines at the start of incubation, but it did not do so in pairs whose nest was removed three times daily. Pairs in this situation would construct a complete nest in a few hours. Singing by males declines at around the start of incubation and is rare when incubation is fully established. The eating of cuttlefish bone by females is almost entirely restricted to the egg-laying period. Only 25% of isolated males build nests, while it is rare for a paired male not to do so. The presence of another bird or birds is the important factor here as groups of four males, monosexual male pairs and males separated from females by bars were all found to build. The results are discussed in relation to previous work on the same species. The controlling influence of external stimuli, whether acting directly on the nervous system or through the mediation of hormones, is stressed.