novel approaches to expression and detection of oestrus in dairy cows

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cows in oestrus (Kiddy, 1977). Hence it should be able to greatly improve the accuracy of detection. This method of detection therefore improves upon existing methods by monitoring 2 different behaviours (standing to be mounted and mounting), with the potential to include activity monitoring in future developments to UWB. This follows from research suggesting that detection rates are improved when methods of detection are combined (Peralta et al., 2005;Lovendahl et al., 2008) for use as one complete method. Another previously reported method of oestrous detection, which is similar to UWB in the way it monitors the cows in all dimensions for both primary and secondary oestrous behaviour is 4sight. 4sight monitors cows through an image database containing images of 4 sides of the cow for identification, and is an optical digital surveillance system identifying cows in heat when they break a photosensitive beam. This method has reported 90% heat detection rate in a commercial situation, although conception rate is reportedly poor (Esslemont, 2006). However this method has not succeeded widely in the commercial sector compared to the various methods of activity monitoring available. UWB has the potential to succeed because of its ability to monitor individual cows in 3D with precision. Detection rates are strongly linked to conception rate (Roelofs et al., 2010), thereby improving detection rate enhances the potential to improve conception rate, and provides an opportunity to adhere to strict calving intervals. Furthermore, although the detection rate reported for UWB is comparable with existing methods such as activity monitoring (At-Taras and Spahr, 2001) and current commercial systems of automated online progesterone monitoring (Friggens et al., 2008) it has the advantage of reporting oestrus in real-time. Therefore unlike retrospective reports of 2 hourly activity units and weak correlations with time of ovulation, the onset of oestrus is known and insemination can occur within 4 to 12 hours (Dransfield et al., 1998). In addition UWB monitors mounting and standing to be mounted which are both strongly linked to the timing of ovulation (Roelofs et al., 2005) and the likelihood of UWB improving conception rates via accurate detection is increased. Further development to the UWB prototype is required and future work would be to monitor oestrous detection in several larger herds. This would determine the possible improvements to oestrous detection rate and by using the real-time properties of UWB investigate the effect on conception 158
ate. By using UWB in a commercial situation a true estimation of the efficacy of UWB as a method of oestrous detection will be gained and comparisons can be made between UWB and current detection methods. Further research possibilities using UWB are discussed in Chapter 5 and could be used to measure behaviour as an indicator of cow welfare and health. The novelty of UWB is 3D position recording and relaying of information in real-time. Cows typically spend 11 hours per 24 hours lying down (Ito et al., 2009) which is a strong indicator of cow comfort (Munksgaard et al., 2005). Using 3D positioning we can determine whether cows have an increased lying time which can indicate lameness (Walker et al., 2008b), and particular times when cows spend more time lying down such as feeding time can be identified which can be used as an indicator of moderate lameness (Yunta et al., 2012). Furthermore UWB may be able to alert the farmer to cases of clinical mastitis due to decreased lying times caused by pain and discomfort (Siivonen et al., 2011;Cyples et al., 2012). Therefore UWB can not only be used for research opportunities but also can be used to advise management and veterinary practices resulting in increased productivity and profit. UWB fulfils the criteria described by Senger (1994) for the optimal method of oestrous detection and is both efficient and accurate at detecting oestrus. UWB has the potential to increase the current oestrous detection rate from 50% (DairyCo, 2009). Increasing detection rate benefits the dairy industry by maximising productivity and increasing profit by adhering to desired calving intervals. If oestrus goes undetected then the strict 365 day calving interval, in which the aim is to produce 1 calf per cow per year, is extended, in turn decreasing overall productivity. Moreover extended calving intervals lead to an increase in forced culling; a significant contributor to greenhouse gas emissions as more animals must be reared to deliver the same level of production. It is reported that an increase of just 10% in oestrous detection rate can reduce the calving to conception interval by 4 days, and the incidence of cows culled for failure to conceive by 6% (DairyCo, 2009). Furthermore poor oestrous detection has other associated costs; extra labour for oestrous detection, more inseminations to get cows in calf, extra semen straws and technicians to artificially inseminate, and veterinary costs all reducing the net profit per cow, decreasing herd profitability (Roche, 2006). Importantly the financial implications of improving oestrous detection rates are large; a mere 10% 159
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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
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Backpack 1 st put on in AI stalls E
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Cows’ behaviour was assessed at 5
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or that the cows were in an area of
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plane, but mostly in achieving high
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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 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: The final section of this thesis de
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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