The influences of buller-effects on the efficiency of feedlot cattle

Transcription

1 Tarryn Attwood Supervisor: Prof. EC Webb The influences of buller-effects on the efficiency of feedlot cattle 31 October

2 Contents Introduction What kind of cattle are affected by buller-steer syndrome? Potential causes Physical effects on the animal Effects on animal productivity How is profitability affected? Current management trends? Suggested management Thank you

3 Introduction Abnormal behaviour often found in cattle that are confined such as in feedlots A buller is defined as an animal that is constantly ridden by his penmates but not for breeding purposes as both the rider and the buller are generally male Harmless riding vs. Bulling The classification of buller is regardless of whether or not the buller is receptive to the riders Listed as one of the three most important health issues in feedlots

4 What kind of cattle are affected by buller-steer syndrome? Are not always the smallest or the weakest animals Above average weight Same outwards appearance Potential to be top performers Have the same level of gains as penmates

5 Potential causes of bulling Hormonal Growth Promotants are often blamed Studies done to test the effect of dose, and type of implants Increase in incidence with Synovex-S Increasing dose increases incidence Possible visual stimulus Side effects of implants Improper placement of implants Current conclusion: HGP may increase the incidence of bulling, but are not the only cause

6 Potential causes of bulling cont. Other factors influencing buller-steer syndrome: Seasonality Environmental conditions and Weather Stress Breed type Castration Body size and age Social interactions

7 Potential causes of bulling cont. Reimplantation Overcrowding Boredom of cattle Pheromones and odours Oestrogen and testosterone levels High level of feeding Implantation technique

8 Physical effects on the animal Secrete a larger amount of endogenous estrogen (both urinary and serum levels (P<0.05)) Higher urinary creatine and 17-hydroxycorticosteroids concentration than normal steers Elevated serum globulin levels (P<0.01) and a lowered A/G ratio (P<0.01) also found Higher plasma total estrogens (P<0.05), but significantly lower serum calcium (P<0.1) and albumin (P<0.01) concentrations Biggest anatomical changes come as the consequences of the constant riding

9 Effects on animal productivity The physical act of bulling may have an effect on the pen mates as well as the buller. The constant disturbance may cause the entire pen to suffer from a lowered ADG (Ulbrich, 1981) Carcasses of bullers are generally downgraded due to discolouration from the bruising, leads to a limited carcass yield, and a loss of income for the feedlot owner

10 How is profitability affected? Financials losses come from many different parts of the feedlot production system Range of $23 (R350, 29) to $70 (R ) per buller loss in income Much higher if the animal dies near to being slaughtered Today a loss of $ would equate to R this monetary loss would warrant a cost of $5 - $6 (R4.35 R5.22 at the time of the survey) per steer for treatment were one available Therefore, feedlot operators that give priority to good buller management techniques will realise fewer financial losses in the long term

11 Current management trends To date, there is no cure for buller-steer syndrome The only known and well-used management strategy is to correctly identify bullers as early as possible and isolate them Holding the bullers in the hospital section of the feedlot for three days while treating stress-related injuries or illnesses, before being returned to their home pens, reduced the average risk of reoccurrence to 30% A second removal of the animals to the hospital for another three days following any relapses, further reduces the risk to 19% Buller pens are found to have few riding incidences even if there is a large number of bullers per pen Some feedlot operators have tried to implement a form of barricade over the pen - generally tends to increase the price of pens

12 Suggested Management Many different trials to find a cure/ treatment that can be used commercially, but there has been little success In 2013, Justman & Justman applied for a patent for a topical solution which can be applied to the backs suspected bullers, either to mask the smell of the buller s phereomones or alter the behaviour of potential riders Other potential solutions generally revolve around prevention more than cure. One study in 2002 noticed a difference in behaviour between heifers that received shade and those that did not heifers without shade had higher incidences of bulling Enrichment of pens may decrease the amount of aggressive behaviours seen between pen mates

13 Conclusion Bulling is an important welfare issue Has the potential to cause significant financial losses, but the true cause is as yet not known More research needs to be done to find a more effective treatment Feedlot managers and workers should be trained to identify and remove bullers as early as possible, and then to keep an eye on them if and when they are returned to their home pens Possible causes need to be minimized as much as possible

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15 Thank You