novel approaches to expression and detection of oestrus in dairy cows

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another cow, attempting to mount other cows and other sexual activities, with pedometer readings (Van Vliet and Van Eerdenburg, 1996). Hence UWB should be beneficial for the more precise timing of AI and could potentially improve conception rates. In the modern herd there is limited use for non-automated methods of detection. Progesterone monitoring is accurate, although not precise at detecting oestrus, and does not relate to exact time of ovulation. Activity monitoring is efficient at detecting oestrus, but is coupled with a large error rate, and although providing an estimated window of time for AI, results in low conception rates because of the lack of relationship between activity increase and timing of ovulation. This could perhaps be related to activity only being recorded in 2 hourly intervals and because activity monitoring is retrospective reporting oestrus only at milking therefore could be reported 12 hours post onset of oestrus. Unlike UWB which records position twice per second, in real-time, alerting staff to perform visual observations and take action as oestrus happens. Hence UWB has the advantage of being efficient and yet accurate by detecting standing heat, the true indicator of oestrus (Orihuela, 2000). This method can also detect mounting, as well as standing to be mounted, which are the signs of oestrus most closely related to time of ovulation, in order to maximise conception rates (Roelofs et al., 2005). 5.4.4 Limitations of UWB Weaknesses of UWB are mainly because it is still in the early stages of development as a prototype system, and because of its prior application (monitoring emergency personnel for example in burning buildings/ forest fires or during natural disasters (Ingram et al., 2004;Ingram, 2006;Harmer et al., 2008;Dona et al., 2009) as it has not been developed for the purpose of monitoring cows. The impractically of the UWB unit size and battery power were major limitations for the purpose of oestrous detection. Having to mount units in backpacks is not ideal and changing batteries at least once every 24 hours is inefficient, requiring excessive labour. However, there is potential to develop the UWB product further, decreasing the size so that it can be worn on the cow’s neck collar, like activity monitors. Furthermore, UWB can be run on lower battery power by removing unnecessary functions included in the prototype and installing an internal battery to last for a prolonged period of time, if not the productive life of the cow. The UWB units must also be robust to avoid breakages of 148
antennae which could affect accuracy of position, which can be rectified by installing an internal antenna. Further potential improvements would be to increase the sampling rate; from 2Hz, twice per second, to perhaps 4Hz, relaying position 4 times per second, which has potential to smooth out any error spikes. This does however pose problems for the number of units functioning at once (20 UWB units at 2Hz, 40 UWB units at 1Hz) because when sampling rate increases, number of units able to communicate decreases. However, current improvements are being made to increase the total number of channels so that more UWB units can communicate. Therefore to strengthen the proof of concept that UWB is suitable for the purpose of oestrous detection, oestrus must be able to be monitored in a herd of cows. With further development to a specification designed for the purpose of oestrous detection UWB could be a marketable product to greatly benefit the dairy industry. 5.4.5 Implications of UWB This study has shown proof of concept that UWB is capable of detecting oestrus in cows. Although the number of cows standing to be mounted is decreasing (Dobson et al., 2008) this is still the most accurate determinant of oestrus (Orihuela, 2000) and timing of ovulation (Dransfield et al., 1998). However, UWB can also detect mounting behaviour of cows in oestrus which is beneficial for detecting oestrus when cows do not display standing heat and also relates to timing of ovulation (Roelofs et al., 2005). Positive implications of using UWB as a method of oestrous detection are that the detection rates can be increased, with potential to exceed the current target of 70% (DairyCo, 2009). This would lead to increased submission rate, at a more accurate time relating to onset of oestrus because UWB communicates continuously in real-time, and thus increase conception rate. Furthermore there are other potential uses of UWB because of the 3D positioning properties. Monitoring the amount of time spent lying down can indicate health and comfort of dairy cows. Cows typically spend 11 hours per 24 hours lying down (Ito et al., 2009) which is a strong identifier of cow comfort as this behaviour takes precedence over feeding and socialising (Munksgaard et al., 2005). This can be used as an indicator of cow comfort; housing design, bedding and general environment. Monitoring the time spent lying down, frequency of lying bouts and duration of individual lying bouts (Haley et al., 2000) can give an indication 149
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NOVEL APPROACHES TO EXPRESSION AND
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TABLE OF CONTENTS TABLE OF CONTENTS
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2.2.3 Statistical Analyses ........
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5.3 RESULTS .......................
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Furthermore, automated software was
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LIST OF FIGURES Figure 1.1 Hormonal
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LIST OF TABLES Table 1.1 Trends in
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LIST OF ABBREVIATIONS ˚ ˚C μM 2D
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CHAPTER 1 - Introduction & Literatu
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the past 50 years and duration of o
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Oestrus growing follicle (Staigmill
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ecomes the main inhibitor of FSH an
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calf at 40-50 days post partum; inv
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al., 2006). However, aged sperm hav
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can occur within 2-3 days, but if t
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educes the incidence of problem cow
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oestradiol, the LH surge and ovulat
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The secondary signs of oestrus can
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There are also changes in normal be
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engage in more natural behaviours i
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1983). Exact explanations and mecha
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2006) and disruption of LH secretio
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1.4.3.2 Milk Yield and Nutrition Di
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influence the ability of the ovary
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cyclicity can be delayed if dietary
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indication for the optimal time to
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calving), 3) pre-breeding heat date
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1.5.2 Physiological Changes Physiol
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1.5.2.3 Body and Milk Temperature T
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physical activity and stage of the
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caused by the general environment t
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may be gained. This is because data
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In summary the objective was to for
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diet, with concentrates at milking.
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oestrus was defined as 3 consecutiv
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The interaction between parity and
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individual oestrus was not signific
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Table 2.4 The effects of the intera
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(361 vs. 578 points, respectively,
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oestrous expression with increasing
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the blood (Sangsritavong et al., 20
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CHAPTER 3 - Single Nucleotide Polym
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population owing to previous select
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Table 3.1 Cont. Follicle Stimulatin
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3.2.4 Sequencing of DNA in the Labo
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was achieved. PCR products were rem
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3.4 DISCUSSION The objectives of th
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fertility and oestrous expression.
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CHAPTER 4 - Development of a Novel
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In summary UWB seems a good option
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Initial tests were carried out to i
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Therefore this demonstrates that X
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which is most important for achievi
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Figure 4.9 Horizontal - Vertical Di
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that UWB is matching the ‘truth
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mounting cow. For example height ch
Page 113 and 114: Backpack 1 st put on in AI stalls E
Page 115 and 116: Cows’ behaviour was assessed at 5
Page 117 and 118: or that the cows were in an area of
Page 119 and 120: plane, but mostly in achieving high
Page 121 and 122: Develop techniques for analysis of
Page 123 and 124: in elastic silicone moulded over a
Page 125 and 126: and time of mount, duration of moun
Page 127 and 128: observed matched with increases in
Page 129 and 130: 5.3 RESULTS Results demonstrate pos
Page 131 and 132: Figure 5.2 Graph showing mounting b
Page 133 and 134: Table 5.1 Results from POC 2 showin
Page 135 and 136: Table 5.3 Efficiency and accuracy o
Page 137 and 138: oestrus and oestrus it is clear to
Page 139 and 140: P4 Concentration, ng/ml P4 Concentr
Page 147 and 148: Activity Activity Activity Activity
Page 153 and 154: 5.4 DISCUSSION The aim of this work
Page 155 and 156: averaged 70% which was lower than t
Page 157 and 158: when the cows lie down, especially
Page 159 and 160: the level of oestrous activity was
Page 161 and 162: technology larger herds must be mon
Page 163: monitoring could also monitor non-l
Page 167 and 168: predispose cows to illness e.g. met
Page 169 and 170: CHAPTER 6 - Overall Discussion & Co
Page 171 and 172: oestrus, h 2 =0.27 (Lovendahl et al
Page 173 and 174: The final section of this thesis de
Page 175 and 176: ate. By using UWB in a commercial s
Page 177 and 178: provides an insight the potential o
Page 179 and 180: BLOWEY, R. (2005) Factors associate
Page 181 and 182: ovine gonadotrophin releasing hormo
Page 183 and 184: GINTHER, O. J., KOT, K., KULICK, L.
Page 185 and 186: associated with embryonic survival
Page 187 and 188: ody condition at parturition on end
Page 189 and 190: Signs in a 24-h Tie-Stalled Dairy H
Page 191 and 192: SHERMAN, E. L., NKRUMAH, J. D., MUR
Page 193 and 194: Influence of negative energy balanc
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