novel approaches to expression and detection of oestrus in dairy cows

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ate decreased dramatically to an average of 53.5%, without any increase in script accuracy; therefore the optimised script resulted in the best oestrous detection. From the daily analysis of the reports of oestrus, mounting and standing behaviour, it was clear that the incidence of erroneously declared mounting was more prevalent on days when cows were actually in oestrus (Tables 5.5 and 5.6). It was also clear that more error was attributed to cows that came into oestrus during the trial compared to control cows not in oestrus. The increased error during oestrus could be due to the number of cows in oestrus at once; for example increased number of cows in oestrus increases oestrous expression (Hurnik et al., 1975;Van Vliet and Van Eerdenburg, 1996), which may mean that the error is a result of the experimental design because 6 cows were synchronised to come into oestrus simultaneously. In a commercial situation the number of cows in oestrus together may be lower which could result in a more accurate detection rate. Spikes in the data affect the accuracy of mounting detection because in the UWB data error spikes are recorded in the same format as actual mounts and so could be mistaken. Falsely declared mounts were investigated by looking at the MU position on CCTV cameras. This showed that there was no pattern associated with the error spikes. Potential reasons could be attributed to a cows’ position in an area of poor geometry in the dairy barn (Figure 4.9), or due to non-line of sight from the master unit (Harmer et al., 2008). Because the dairy farm is a complex environment with various obstructions, line of sight may become obstructed and thus cause reflections in the signal which give false or less accurate 3D positions. Although, filtering by script analysis can help to eliminate these spikes. Upon further analysis of the data from POC 2 and POC 3 it appears that data quality in POC 2 was better than POC 3, therefore data from POC 3 required further filtering. It is obvious that 2 MUs in POC 3 had higher incidence of error and more false positives were declared by script analysis (Cow 38 and 623; control cow and oestrus cow). These particular MUs were tested against a normally functioning MU in the same BU network in the same positions of good geometry; results revealed no difference in position or error, leading to the conclusion that error could be attributed to a cow’s favoured position within the location, which could be an area of poorer geometry and more obstruction. Furthermore it is possible that 140
when the cows lie down, especially in areas of poor geometry, that MUs may lose line of sight with the master unit or become obstructed by other objects or cows, which could contribute to error. In summary, these results were extremely important in providing the basis for automated detection of oestrus by UWB; because error increased on days of oestrus and was associated with cows in oestrus. Hence a clear distinction could be made between those cows in oestrus, thus eligible for AI, and those that were not showing behavioural oestrus. 5.4.2 UWB for Automated Oestrous Detection This novel method of oestrous detection accurately detected all the 9 cows in oestrus in this study using automated analysis of UWB data. The herd level script was developed to detect oestrus in a group of cows following analysis of UWB error, which as discussed increased with oestrous behaviour. The herd level script can detect initial mounting behaviour and therefore identify cows coming into oestrus. If mounting and/ or standing to be mounted continue and occur again within 3 hours the cow is deemed in oestrus. In total 10 cows displayed oestrus during trials POC 2 and 3, although one cow was discounted from analysis (as explained above), therefore these results show that 9 out of 9 cows (100%) can be detected in oestrus automatically by continuous monitoring of cows’ 3D position to detect mounting and standing to be mounted. In support of these results 6 out of 6 cows were also correctly identified as not being in oestrus. Time of onset of oestrus, mounting, can also be determined although this requires further investigation. This sign of oestrus is important to monitor because mounting and disorientated mounting are more intense behaviours which are displayed around the time of oestrus (Van Eerdenburg et al., 1996). Therefore in the case that standing to be mounted is not displayed, as fewer cows stand to be mounted (Dobson et al., 2008), mounting can be a useful indicator of oestrus. Importantly standing to be mounted can also be identified, as this is the definitive sign that a cow is in true oestrus (Orihuela, 2000). Standing to be mounted is also the most closely related sign of oestrus to ovulation and therefore if the time of onset is known provides an accurate prediction for ovulation and when to AI. Standing heat occurs 26.4 hours before ovulation (Roelofs et al., 2005), showing how real-time UWB detection of standing to be mounted can be a useful predictor for time of AI which is required in order to maximise conception 141
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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
Page 105 and 106: which is most important for achievi
Page 107 and 108: Figure 4.9 Horizontal - Vertical Di
Page 109 and 110: that UWB is matching the ‘truth
Page 111 and 112: 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: averaged 70% which was lower than t
Page 159 and 160: the level of oestrous activity was
Page 161 and 162: technology larger herds must be mon
Page 163 and 164: monitoring could also monitor non-l
Page 165 and 166: antennae which could affect accurac
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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