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Item A study of the effects of post-mating progesterone supplementation on the reproductive performance in the ewe : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in animal science at Massey University(Massey University, 1989) Walsh, Peter AllanThe aim of this study was to investigate the effects of post-mating progesterone supplementation, in the form of CIDRs, on the reproductive performance in recently mated ewes. The effect of two nutrition treatments were also examined by feeding two different pasture allwances to these ewes during a two week period immediately folliwing a synchronized mating. Two hundred and thirty four Border Leicester X Romney first cross ewes, compresed of 130 mixed-age ewes (3-8 years) and 104 two-tooth (maiden) ewes were flushed on increasing pasture allowance prior to joining. These ewes were naturally mated at a synchronized oestrus following a 13 day CIDR treatment period. During the three days following CIDR withdrawal, 88.0% of the ewes were mated. The mixed-age ewes came into oestrus significantly earlier that the two-tooth ewes (P < 0.001). There was a significant linear relationship between liveweight and onset of oestrus (P < 0.05), with the heavier two-tooth ewes coming on oestrus earlier than the lighter two-tooth ewes. This was not apparent in the mixed-age ewes. On Day 2 following mating, ewes were randoaly divided into either the high or low pasture allowance levels. Pasture allowance levels were monitored using an Ellinbank Pasture Meter (EPM). Levels of feed intake were estimated for a random sample of 20 ewes both before and after mating through the use of intraruminal chromium releasing devices (CRDs). Sward heights (representing quantity), botanical composition and in vitro digestibilities (representing quality) were recorded for both the flushing and the post-mating period. This information led to the estimation of voluntary herbage intakes during the flushing period (Period I) of 1.2 M, while the intake levels of the ewes following the mating (Period II) were calculated to be approximately 1.6 M and 1.0 M for the high and low pasture allowance levels, respectively.Item Biosensors for fertility and pregnancy in cattle : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry at Massey University, Palmerston North, New Zealand(Massey University, 2013) Hsu, Yu-TingThis project is focused on progesterone sensing, using both surface plasmon resonance (SPR) and lateral flow immunoassay (LFIA) methods with a new progesterone (P4) sensing material to develop cost effective assays for progesterone sensing in bovine serum and milk samples. P4-PEG-OVA was synthesised, characterised and used for P4 detection. The P4-PEG-OVA sensor surface showed an improvement in surface response compared with two shorter ligand 4TP-P4-OVA and 4TPH-P4-OVA in SPR studies. An analysis method has been developed and modified for bovine serum and milk analyses. The results indicated the P4-PEG-OVA ligand allowed sensitive P4 detection in SPR sensing and allowed bovine P4 cycle profiling. The SPR analysed data was compatible with the ECLIA and ELISA independent analyses and the P4 cycle of each of the three bovine milk samples showed a very similar trend and the extraction level was also consistent. The P4-PEG-OVA ligand was used to develop a LFIA sensor strip, and the inhibition assay for bovine serum and milk analyses established. The results indicated that, after appropriate sample pre-treatment, the bovine estrous cycle profile could be detected. The LFIA method can be a potentially quick, easy and cost effective semi-quantitative P4 analysis for serum and milk samples. A new material, polyhydroxyalkanoate (PHA) granules has been investigated for the possibility of developing a new surface biosensor. From the surface studies, the results indicated that the 3GNZZPhaC beads have the potential to become an alternative binding material for SPR sensing due to its unique gold binding property. A flow cell was designed, constructed, and tested on 3GNZZPhaC beads prior the preliminary SPR investigations. The ZZPhaC beads also showed the gold binding property and ZZPhaC beads were used for SPR studies. The results suggested a possible application for them as a new SPR binding material for antibody detection.Item Improving the response to synchronisation programmes of dairy cattle : a thesis presented in partial fulfilment of the requirement for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Palmerston North, New Zealand(Massey University, 2014) Sahu, Santosh KumarA gonadotrophin, prostaglandin, gonadotrophin + progesterone (GPG+P4) programme with fixed-time artificial insemination (FTAI) is the current recommended synchronisation programme for both heifers and anoestrous cows on New Zealand dairy farms. However, it is an expensive programme and a better understanding of the role of all of its components would be very useful in developing alternative cheaper programmes. The two components of the programme that are the least understood, in terms of their underlying physiological actions and how they influence the outcome of synchronisation, are the Day 0 gonadotrophin-releasing hormone (GnRH) injection and the progesterone device. Additionally it is well known that energy status has a significant impact on fertility but there is little evidence, particularly under New Zealand conditions, of how energy status affects the response to GPG-based treatments in anoestrous postpartum dairy cows. The effects of a GPG (Day 0: 100 µg GnRH, Day 7: 500 µg PGF2a, Day 9: 100 µg GnRH) programme upon follicular and luteal dynamics, ovulation synchronisation and patterns of oestradiol and progesterone secretion in postpartum anoestrous dairy cows and nulliparous dairy heifers were compared with (i) a GPG programme plus a progesterone insert from Days 0–7 (GPG+P4) and (ii) a GPG+P4 programme from which the first GnRH treatment had been omitted (P+G+P4). Interactions of each treatment with energy balance, as determined by NEFA, IGF-I and insulin concentrations, were also studied in postpartum anoestrus cattle. Finally the conception rate (CR) to fixed time AI of a GPG+P4 programme in which AI was done concurrent with the Day 9 GnRH injection (Cosynch) was compared with a progesterone + prostaglandin programme (P4+PG; Day 0–7: progesterone releasing intravaginal device, morning of Day 6: 500 µg PGF2a, afternoon of Day 9: FTAI) in heifers. The physiological effects of the GPG and the GPG+P4 programmes were similar in anoestrous dairy cows. The inclusion of the Day 0 GnRH still appeared feasible in a GPG programme for treating anoestrous cows as it led to a higher probability of a corpus luteum (CL) on Day 7. In addition, treatment response was significantly affected by the postpartum duration and negative energy balance as evidenced by the significantly higher NEFA concentrations on Days 0, 7 and 9, and a lower insulin concentration on Day 0, in cows that failed to ovulate in response to the synchronisation protocol compared with cows that did ovulate. A clear and significant relationship between NEFA concentrations and ovulation in response to all synchronisation protocols showed that, regardless of the regimen that was used to treat anoestrus, the response was moderated and limited by the degree of negative energy balance. In heifers, the removal of the progesterone-releasing device from a GPG+P4 programme had no effect on follicular dynamics or on the proportion of heifers which ovulated after either the GnRH injection on Day 0 or Day 9. Additionally, unlike the anoestrus cows, omitting the GnRH injection on Day 0 did not result in significantly delayed ovulation at the end of the programme, inasmuch as treatment with P+G+P4 was associated with earlier ovulation than GPG. Furthermore, synchronising heifers with a significantly less expensive programme (P4+PG) resulted in similar CR to synchronising with GPG+P4 (54.8% versus 52.4%, respectively) further confirming that Day 0 GnRH was not essential in heifer synchrony. In conclusion, the higher conception rate in cows treated with a GPG+P4 programme rather than a GPG programme reported previously does not seem to be modulated by the actions on follicular dynamics and improved synchronised ovulation in dairy cattle with postpartum anoestrous (or in nulliparous heifers); however, the treatment response in anoestrous cows can be significantly affected by negative energy balance. In contrast, in dairy heifers, no benefit of Day 0 GnRH or the progesterone device in a GPG+P4 programme suggests the possibility of more cost effective options (e.g. P4+PG) which can lead to a CR as high as those synchronised using a GPG+P4 programme.Item Synchronization of follicular development, oestrus and ovulation using oestradiol benzoate and progesterone in dairy cattle : a thesis presented in partial fulfillment of the requirements for the degree of Master of Philosophy (Veterinary Clinical Science) at Massey University(Massey University, 2000) Abdullah, PuniminThe aim of oestrus synchronisation in cattle is to achieve a close synchrony of oestrus and ovulation with high submission rates. The status of follicular wave development at the time of treatment has been responsible for a large portion of the variability in ovarian response to treatments employed. The control of oestrus and ovulation require firstly that the life span of the corpus luteum is reduced, and secondly that follicular wave emergence is synchronized so that a healthy, oestrogen active dominant follicle is present at the end of the treatment. A clinical trial was conducted to determine the effective dosage of oestradiol bezoate in combination with progesterone on follicular dynamics, oestrous behaviour and time of ovulation when treatment was administered intravaginally. Intravaginal treatment with 2 mg or 7 mg oestradiol benzoate and progesterone on day 3 of the oestrous cycle was effective in inducing atresia of the dominant follicle and a new cohort of follicles began to emerge, on average, 2.5 ± 0.93 days after treatment. However, the IBD Onsettl2TM drug adminstration device, failed to maintain the required progesterone output and plasma concentrations during the treatment period. This resulted in failure to synchronize oestrus and ovulation. IBD Onsett12TM, as a single application intravaginal drug delivery device for the purpose of controlling the oestrus cycle in cattle, was further evaluated in cycling and non-cycling cows and compared to the CIDR oestrus synchronization program. A total of 350 Friesian or Friesian cross cows in five herds were involved in the trial. The retention rate for the IBD Onsett12TM was significantly lower than the CEDR (65.12% vs. 99.44%, χ2 = 73.528, P = 0.001), and the synchronized conception rate from the CIDR protocol was significantly higher than the IBD Onsett12TM among cycling and non-cycling cows (χ2 = 15.087, P = 0.02). The IBD Onsett12 oestrus synchronization program was effective in inducing fertile synchronized oestrus in some cycling and non-cycling cows, but resulted in a low synchronized conception rate. Manipulation of follicular development and controlling the oestrous cycle length will synchronize oestrus more precisely and control the time of ovulation more exactly to allow a single fixed-time insemination. Controlling the time of new follicular wave emergence and synchronizing the follicular wave status in dairy cows at random stages of the oestrous cycle would provide a more practical and less variable method of synchronization than those of the past. A clinical trial was conducted to control both follicular development and luteal function. Twenty randomly cycling, non-lactating dairy cows were randomly assigned to two treatments; 1) 2 mg oestradiol benzoate injected intramuscularly and 200 mg of progesterone subcutaneously, 9 days before prostaglandin (500 μg cloprostenol) and a second injection of 1 mg oestradiol benzoate 24 hours after prostaglandin treatment (ODB, n = 10). 2) 10 μg busereiin injected 7 days before prostaglandin (500 μg cloprostenol) and a second injection of 10 μg busereiin 48 hours after prostaglandin treatment (GnRH, n = 10). An acute short-acting treatment with progesterone and oestradiol benzoate or busereiin was effective in inducing atresia of the dominant follicle. A new follicular wave emerged earlier in the GnRH treated group than in the ODB treated group (2.22±0.15 vs. 3.60±0.22 days, P = 0.001). An LH surge occurred earlier after a second buserelin treatment on day 9 than after a second oestradiol benzoate treatment on day 10 (4.0 ± 1.0 vs. 22.80 ± 1.20 hour, P = 0.001). The mean time of ovulation after the second oestradiol benzoate or buserelin treatment was not significantly different between the ODB and the GnRH group (1.70 ± 0.30 vs. 1.56 ±0.18, P = 0.692). The proportion of cows that were observed in oestrus was higher in the ODB group than the GnRH group (100% vs. 55.6%, χ2 = 5.630, P = 0.018). In conclusion, progesterone and oestradiol treatment intravaginally or intramuscularlly was effective in synchronizing follicular wave emergence. Administration of oestradiol benzoate 24 hours after prostaglandin given 9 days after an initial progesterone and oestradiol treatment produced the oestrus synchrony, induced an LH surge and provide a degree of synchrony in the time of ovulation. This program showed potential in manipulating follicular development and luteal function and has the possibility allowing fixed-time insemination. However, the efficacy of the EBD Onsett12TM as a single application intravaginal drug delivery device to control the oestrous cycle or as progesterone-releasing device in cattle did not demonstrate satisfactory results when used in these trials. This might arise from the complexity of the drug delivery system. Nevertheless, the concept of delivering multiple drugs at different rates and times may have many benefits to the end user when current design and use problems arc resolved.Item A study of some effects of progesterone and pregnant mares' serum (PMS) on reproductive phenomena in the anoestrous Romney ewe : a thesis presented at Massey Agricultural College in part fulfilment of the requirements for the degree of Master of Agricultural Science in the University of New Zealand(Massey University, 1955) Lamond, D. R.No abstract.Item The effect of estrogen and progesterone on sex differences in susceptibility to noise[-]induced hearing loss : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Occupational Health and Safety at Massey University, Manawatu, New Zealand(Massey University, 2013) Hislop, Renee AdeleThere is some evidence suggesting that males and females differ in susceptibility to noise induced hearing loss (NIHL): that is, they differ in NIHL magnitude even when exposed to the exact same noise exposure (1, 2), and that this may be related to the effects of circulating levels of the female sex hormones estrogen and progesterone on the cochlear response to noise (3-8). The main objective of this research was to determine what effect estrogen and progesterone levels had on sex differences in susceptibility to human temporary threshold shift (TTS) and otoacoustic emission (OAE) shift. A secondary objective was to determine whether estrogen and progesterone levels impacted on the prediction of susceptibility to NIHL using measures of auditory physiology: OAE amplitude, efferent suppression magnitude and 4 kHz pure tone audiometry thresholds. Additionally, it was determined whether the female sex hormones acted to influence susceptibility to NIHL via their effect on these measures of auditory physiology or whether hormones acted independently of these effects to influence susceptibility to NIHL. 25 female and 21 male participants aged 18-35 were exposed to a 3 kHz, continuous, pure-tone noise exposure at 100 dB LAeq for 15 minutes in their right ear. This exposure provided the equivalent energy to an eight-hour continuous A-weighted sound pressure level, LAeq,8h of 85 dB. To address the main objective TTS, OAE shift and recovery from TTS and OAE shift were compared in males and females. Serum levels of estrogen and progesterone were measured in female participants and correlations were made between these levels and TTS and OAE shift data. To address the second objective correlations were calculated between auditory physiology measures, TTS and OAE shift for males and females as well as between the sex hormones and auditory physiology measures. Additionally, linear regression models were produced to assess the mediating role of the auditory physiology measures on the relationship between hormones TTS and OAE shift. This research found no difference between males and the entire group of females in susceptibility to TTS, OAE shift or recovery from OAE shift, although females had a slower recovery from TTS. However, when circulating levels of estrogen and progesterone levels were accounted for a sex difference in TTS was apparent. This difference was driven by a large, significant, negative correlation between progesterone levels and TTS, whereas estrogen had no significant correlation with TTS or OAE shift. However, estrogen mediated different aspects of auditory physiology, whereas progesterone did not. There was no interaction between the effects of estrogen and progesterone on TTS or OAE shift. Additionally, there was a mediating role of some aspects of auditory function on the effects of estrogen on TTS and to a greater degree on OAE shift. However, estrogen itself only had a small non-significant impact on TTS and OAE shift so this suggests that the impact of auditory function and hormones on TTS and OAE shift are independent.Item Mammogenesis in the ovariectomized mouse : a study of the effects of estradiol and progesterone : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Physiology at Massey University(Massey University, 1972) Mackenzie, Helen MaryImmature ovariectomized female mice of the NOS albino strain were administered a series of estradiol treatments, and estradiol plus three different levels of progesterone, for 21 days in two separate experiments. Uterine weights, mammary gland areas, duct junctions/unit area, total duct junctions, mammary DNA and RNA were measured for all animals. Statistical analysis was carried out on all data. At estradiol doses between 0.00125-0.320 ug/day there was a steady increase in uterine weight, while mammary areas, unit junctions and total junctions increased to a peak at 0.020 and 0.040 ug/day estradiol respectively followed by an inhibition at higher levels. Changes in DNA and RNA did not follow this pattern but were more constant. At all progesterone doses an inhibition in uterine growth was seen when combined with 0.0050 ug/day estradiol, and a maximum was reached when the progesterone was combined with 0.010 ug/day estradiol, above which paint the curve remained flat showing an inhibition from growth observed with estradiol alone. The inhibition when 0.0050 ug/day estradiol was combined with progesterone was observed with all other parameters and also the inhibition at high levels of estradiol. However the final levels were higher than with estradiol alone. A third smaller experiment was carried out to show the time course of development of the mammary glands with 0.010 ug/estradiol and 0.010 ug/day estradiol plus 1 progesterone tablet. Mice were slaughtered at 3 day intervals during the 21 day treatment period. The results are discussed in relation to previous studies on mammary growth in ovariectomized mice and further areas of work suggested.Item Reproductive performance and the transition period of thoroughbred mares in New Zealand : evidence and implications for future alternative management strategies : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Veterinary Science at Massey University, Palmerston North, New Zealand(Massey University, 2012) Hanlon, David WilliamThe aims of this research were to investigate the reproductive performance of Thoroughbred mares in New Zealand, to examine the use of intravaginal progesterone to manage transitional mares and to develop a potential model for haemorrhagic anovulatory follicle (HAF) development in the mare. Firstly, a prospective cohort study was performed involving five stud farms in the Waikato region of New Zealand during three consecutive breeding seasons (2006-2008). A total of 1482 individual mares contributed 2007 mare years and 3402 oestrous cycles over the three breeding seasons. The mean first-cycle pregnancy rate was 53.6%, the end-of-season pregnancy rate was 85.3% and the foaling rate was 80.2%. The length of the breeding season was relatively short with 87% of services occurring in the 91 day period between 1st September and 30th November. Multivariable analyses revealed that reproductive performance was influenced by two main mare-related factors; the age of the mare and her reproductive status (dry or foaling). Increasing mare age significantly reduced the first-cycle pregnancy rate, reduced the end-of-season pregnancy rate and increased the interval from the start of the breeding season to conception. In terms of reproductive status, dry mares had a significantly higher first-cycle pregnancy rate and end-of-season pregnancy rate compared with foaling mares. The majority of variation in reproductive performance was associated with mare-level factors and the contribution of the stallion and stud farm was relatively minor. Transitional mares treated with intravaginal progesterone at the start of the breeding season were served two weeks earlier than untreated control mares. In the first 21 days of the season, 95% of treated mares were served compared with 43% of control mares. Treated mares also conceived earlier and had a higher end-of-season pregnancy rate than control mares. Follicle development in response to intravaginal progesterone treatment iii appeared to be mediated through a close temporal association between progesterone, FSH and LH during treatment. In the last study, transplantation of chorionic girdle into non-pregnant mares resulted in elevated eCG concentrations in all mares and the development of multiple HAFs in the treated mares over a prolonged time-span. In conclusion, this research has, i) identified the most important factors associated with the reproductive performance of New Zealand Thoroughbred mares, ii) determined that intravaginal progesterone treatment is a suitable management tool for transitional mares and iii) created a model for HAF development in the mare.Item Refinement of analytical technologies for detection of biomolecules of importance to the dairy sector : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Sciences at Massey University, Palmerston North, New Zealand(Massey University, 2011) Sharma, Indu; Sharma, InduThere is a continuous push on the dairy industry to enhance livestock productivity to meet with the demands of ever increasing human population. This demand can be achieved by developing rapid and early diagnostic aids to help curtail various problems encountered in the livestock production. The first study of the present thesis was focussed on standardizing initial steps towards development of Surface Plasmon Resonance for progesterone and oestradiol 17- , both of which are critically implicated in animal reproduction. For progesterone, the binding response of two different length linkers, and the antigen-antibody binding response of two different source monoclonal antibodies (P1922 from Sigma vs SE-7720-1430 from Serotec) were evaluated. It was concluded that the long length linker had better binding response than the short length linker. The antibody obtained from Serotec (SE-7720-1430) had greater sensitivity but its binding response was inconsistent. On the other hand, the sensitivity of the monoclonal antibody from Sigma (P1922) was lower, although its binding response was consistent. For oestradiol 17- , antibody procured from Bio-trend (BT70-1020-06) was tested and its binding response was consistently low on all the test days. This study thus suggests that careful testing and selection of antibodies to achieve desired antigen-antibody binding response is a critical step towards development of SPR for progesterone and oestradiol 17- . The second study was undertaken to refine the currently existing fluorescent techniques to measure phytoporphyrin in the peripheral circulation of cows. Phytoporphyrin is implicated in facial eczema (FE), which is a photosensitization disease of high economical importance. This occurs due to disturbances in the chlorophyll metabolism as a result of liver damage and bile duct occlusions caused by fungal toxicity. The present study described new modified fluorescent methods to measure phytoporphyrin in the serum of cows. Further, the absorption and emission spectra of phytoporphyrin were compared with that of other chlorophyll metabolites and thus a currently existing anomaly in the chemical structure of phytoporphyrin was rectified.