Cattle temperament affects reproduction

Cattle temperament affects reproduction

In beef cattle production systems, the word "temperament" is used to describe the fear-related responses of cattle to human interaction.

*Dr. John Arthington is with the University of Florida's Range Cattle Research & Education Center in Ona, Fla. Dr. Reinaldo Cooke is with Oregon State University's Eastern Oregon Agricultural Research Center in Burns, Ore. To expedite answers to questions concerning this column, please direct inquiries to Feedstuffs, Bottom Line of Nutrition, 5810 W. 78th St., Suite 200, Bloomington, Minn. 55439, or email [email protected]

In beef cattle production systems, the word "temperament" is used to describe the fear-related responses of cattle to human interaction.

Cattle may display poor temperament for a variety of reasons, some of which may include: (1) genetic disposition, (2) previous handling experiences or (3) fear of a new or novel occurrence or interaction.

For reasons related to animal well-being and human safety, improvements in cattle temperament have been sought through improved handling and management protocols and selective breeding. Through these efforts, researchers and cattle producers have begun to recognize an association among cattle temperament and growth (Fell et al., 1999) and carcass quality (Voisinet et al., 1997).

Efforts at the University of Florida Range Cattle Research & Education Center embarked on research to investigate the influence of temperament and acclimation procedures on measures of reproductive performance of Bos indicus-influenced commercial beef heifers and cows. These studies were conducted as part of Dr. Reinaldo Cooke's doctoral dissertation research (Cooke et al., 2009a and 2009b).

This article will illustrate the findings of these two studies. Since this time, Cooke, now a faculty member of Oregon State University's Eastern Oregon Agricultural Research Center, has expanded these research findings in both Bos taurus (Cooke et al., 2012) and Bos indicus (Cooke et al., 2011) cows. Those findings will be presented in an upcoming Feedstuffs Beef Bottom Line contribution.

 

Heifers

Progesterone is an important hormone of the reproductive system. It is primarily derived from the corpus luteum, which is a tissue that forms on the ovary following ovulation.

However, the adrenal gland serves as a secondary source of progesterone, and at times, particularly during periods of stress, this adrenal-derived progesterone may be significant. Therefore, we hypothesized that that heifer and cow temperament may affect reproduction during the peripubertal (heifer) and postpartum anestrous (cow) periods.

The objective of the first study was to evaluate how acclimation to handling through a cattle working facility affects measures of growth, puberty attainment and pregnancy in developing heifers. The study was conducted over two consecutive years with 40 heifers enrolled each year.

Heifers were weaned at approximately seven months of age and randomly assigned to be acclimated or not (control). The acclimation procedure involved handling the heifers three times weekly (Monday, Wednesday and Friday) for four weeks. Specifically, the heifers were walked from their pasture to the cattle working facility (1.25 miles round trip).

In week 1, the heifers were not restrained but were simply allowed to walk through the chute and back to the pasture. In subsequent weeks, they were restrained in the squeeze chute with gradually increasing time intervals (ranging from five to 30 seconds for weeks 1-4, respectively).

The timeline of the study was: weaning on day 0, acclimation procedure on days 11-39 and breeding season on days 131-191. Heifer temperament was assessed on days 10 and 40, and blood was sampled throughout the study for assessment of puberty attainment and measurement of stress proteins.

Results. Heifers receiving the acclimation procedure gained 0.18 lb. per day less over the entire study than the control heifers (Table).

We attributed this difference to the added exercise and calories expended during the acclimation. For those heifers, this process involved a total walking distance of 15 miles. In addition, grazing was interrupted during each acclimation event when the heifers were removed from their pasture and walked to the cow pens.

Although the acclimated heifers had less bodyweight gain, they also had lower blood concentrations of cortisol (Table), which is a protein produced in response to stress, suggesting that the acclimated heifers were experiencing a lesser amount of stress during the handling and sample collection procedure compared to the control heifers.

Despite a reduced bodyweight gain, the acclimated heifers achieved puberty sooner (Figure) and became pregnant earlier in the breeding season compared to control heifers. The implications of these data suggest that acclimating prepubertal, Brahman-crossbred beef heifers to standard cattle working facilities and human presence may hasten the age of puberty and pregnancy attainment.

 

Cows

In a second study, we sought to assess the effects of acclimation to humans on measures of temperament and pregnancy of Brahman-crossbred cows.

The objective of this study was to determine if temperament and pregnancy attainment could be improved in mature beef cows exposed to a human presence acclimation procedure.

This study was conducted over two consecutive years using a total of 395 cows assigned to 14 individual pastures. Two treatments — acclimated and non-acclimated (control) — were randomly assigned to pastures (seven pastures per treatment annually).

The acclimation procedure was applied from August to January, which was prior to and following the calving season (October to January). The procedure involved visiting the herds twice weekly, walking among the cows for 15 minutes per herd and offering small amounts (1-2 oz.) of cattle range cubes, which provided no meaningful nutritional contribution. The control cows remained undisturbed.

Results. The acclimation procedures in experiment 2 yielded no meaningful changes in cow bodyweight, plasma cortisol concentrations or temperament (Table). The effect of acclimation on cow pregnancy rate was inconsistent among years and breeds.

In general, there were no effects of acclimation on pregnancy, with the exception of Braford cows in year 1, when the acclimation procedure resulted in more Braford cows becoming pregnant earlier in the breeding season.

Interestingly, although the acclimation procedure did not affect changes in temperament score among cows or the likelihood of pregnancy, there was a significant linear relationship among temperament score and pregnancy rate for all cows. Irrespective of acclimation treatment, cows with poorer temperament scores were less likely to become pregnant compared to cows with calmer temperaments.

The implications of these data suggest that acclimating mature Brahman-crossbred beef cows to human presence appears to have no effect on changes in cow temperament or the probability of pregnancy. However, an overall influence of cow temperament on attainment of pregnancy was discovered.

 

The Bottom Line

Overall, these findings suggest that the role temperament plays in measures of well-being and productivity of beef cattle is becoming better understood. The results of these two studies suggest that temperament has an important and measurable influence on the likelihood of achieving pregnancy in a controlled breeding season.

The effectiveness of acclimation procedures appears to be age dependent in that they were effective at improving reproductive measurements in growing heifers but not in mature cows.

Further research is warranted to investigate other methods of acclimation and to further assess the impact of cow age on response to acclimation protocols.

 

References

Cooke, R.F., J.D. Arthington, D.B. Araujo and G.C. Lamb. 2009. Effect of acclimation to human interaction on performance, temperament, physiological responses and pregnancy rates of Brahman-crossbred cows. J. Anim. Sci. 87:4125-4132.

Cooke, R.F., J.D. Arthington, B.R. Austin and J.V. Yelich. 2009. Effects of acclimation to handling on performance, reproductive and physiological responses of Brahman-crossbred heifers. J. Anim. Sci. 87:3403-3412.

Cooke, R.F., D.W. Bohnert, B.I. Cappellozza, C.J. Mueller and T. DelCurto. 2012. Effects of temperament and acclimation to handling on reproductive performance of Bos taurus beef females. J. Anim. Sci. 90:3547-3555.

Cooke, R.F., D.W. Bohnert, M. Meneghetti, T.C. Losi and J.L.M. Vasconcelos. 2011. Effects of temperament on pregnancy rates to fixed-timed AI in Bos indicus beef cows. Livest. Sci. 142:108-113.

Fell, L.R., I.G. Colditz, K.H. Walker and D.L. Watson. 1999. Associations between temperament, performance and immune function in cattle entering a commercial feedlot. Aust. J. Exp. Agric. 39:795-802.

Voisinet, B.D., T. Grandin, S.F. O'Connor, J.D. Tatum and M.J. Deesing. 1997. Bos indicus-cross feedlot cattle with excitable temperament have tougher meat and a higher incidence of borderline dark cutters. Meat Sci. 46:367-377.

 

Average daily gain (ADG), temperament score and plasma cortisol concentrations of heifers exposed, or not, to an acclimation procedure

 

 

 

Std. error

 

Item

Acclimated

Control

of means

P-value

ADG, lb./day*

1.10

1.28

0.04

< 0.01

Temperament score**

2.46

2.48

0.096

0.93

Plasma cortisol, ng/mL

38.5

51.0

3.5

< 0.01

*Calculated over the entire 191-day study.

**Calculated from a pooled assessment of heifer behavior in the squeeze chute, velocity exiting the squeeze chute and behavior in a pen with an observer present.

Cattle temperament affects reproduction

 

Volume:85 Issue:28

Hide comments

Comments

  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
Publish