The effect of dietary nitrogen on nitrogen partitioning and milk production in grazing dairy cows : A thesis presented in partial fulfilment of the requirements for the Master of Animal Science at Massey University Palmerston North, New Zealand

Two experiments were conducted during spring (8th October to 12th November 2009) as part of a larger study, to study the effects of increasing levels of crude protein (CP) in pasture on milk production, dry matter intake (DMI) and nitrogen (N) partitioning in dairy cows. The first experiment was undertaken over 25 days (8th October to 1st November 2009), where fifteen multiparous, rumen fistulated, early lactation Holstein-Friesian cows (505 ± 10.4 kg liveweight; 4.1 body condition score ± 0.044, mean ± standard deviation) were assigned to one of three urea supplementation treatments: Control (0 g/day urea; ~20% CP), Medium (350 g/day urea; ~25% CP) and High (690 g/day urea: ~30% CP). Urea was supplemented to the pasture-based diet to increase CP content while maintaining similar concentrations of all other nutrients across treatments. All cows were offered ~20 kg dry matter (DM)/day perennial ryegrass-based pasture (CP = 20.6 ± 0.56% DM; metabolisable energy (ME) = 11.8 ± 0.06 MJ/kg DM). Cows were acclimated to their urea treatment over a 25 day experimental period. The objective of this study was to determine the effect of increased dietary CP in grazing cows on DMI and milk yield. Dry matter intake was estimated using a back calculation method from the energy requirements of the cows. The results indicate a complex interaction between DMI, milk yield and urea intake. As dietary CP increased, the milk yield increased; however, as urea’s contribution to total dietary CP concentration increased, the increase in both DMI and milk yield was less. Milk yield decreased when urea supplementation increased beyond 350 g/day, and the interaction evident in milk yield was mirrored in yields of fat, CP and lactose (P <0.001). The addition of urea had no effect on milk fat, protein and lactose percentages. The second experiment was conducted over 22 days (22nd October to 12th November 2009), involving ten multiparous, rumen fistulated, early lactation Holstein-Friesian cows (520 ± 5.6 kg liveweight; 4.15 body condition score ± 0.078, mean ± standard deviation). This experiment was undertaken to study N partitioning in pasture-fed grazing dairy cows using urea supplementation as a non-protein N (NPN) model to ensure all other nutritional characteristics of the forage remained the same. All cows were offered ~19 kg DM/day of perennial ryegrass-based pasture (CP = 18.4 ± 0.64% DM; ME = 11.4 ± 0.06 MJ/kg DM). Cows were assigned to one of two experimental groups: Control (0 g/day urea; ~18% CP), and a Urea supplemented group (350 g/day urea; ~23% CP). Cows were acclimated to the diets and metabolism stalls for 14 days, and a further 7 days were used for total collection of urine, faeces and milk. Increasing dietary CP content had no effect on DMI, milk yield, milk composition, and faecal N. Urinary urea N (UUN) and urine N yield and concentrations increased as dietary CP content increased however, urinary creatinine, ammonia (NH3), calcium and magnesium were not affected. Rumen urea and NH3 concentrations were increased as CP content increased. Milk urea N showed trends for linear responses to increasing N intake (P <0.001, R2 = 0.47). A 16.5% increase in N intake resulted in a 42.5% increase in milk urea nitrogen (MUN) concentration; however, the relationship was restricted to low MUN concentrations. Urinary N increased linearly as a result of N intake, although the relationship was restricted due to the underestimation of urinary N and the limited range of N intake values. The 28% increase in urinary N excretion resulted from a sharp 3.6% decline in N efficiency as dietary N content increased. The main conclusions of this thesis were the ability for excessive urea intake to reduce milk yield in grazing dairy cows. Further research is needed to determine if high soluble NPN concentrations in fresh pasture would affect DMI and milk yield in the same way. Increasing N intake results in linear increases in MUN, urinary N and UUN. These relationships could provide useful tools to predict urinary N excretion due to the strong relationships between these variables. Further research is needed to develop robust prediction equations for the relationships between these variables in grazing dairy cows before they could be used as regulatory tools

Behavior changes in grazing dairy cows during the transition period are associated with risk of disease : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Animal Science at Massey University, Manawatū, New Zealand

There is growing interest in the use of behavior data derived from accelerometers as a potential measure of animal health, however, research determining the optimal use of these devices and the interpretation of data derived from them, is lacking, particularly in grazing systems. The aims of this thesis were to understand: 1) data management considerations that need to be taken into account when using accelerometer devices to measure behavior in a research setting; 2) environmental and other potentially-confounding variables that can influence cow behavior and, therefore, the interpretation of behavior data; 3) ‘normal’ behavior of clinically-healthy grazing dairy cows during the transition period, and; 4) changes to behavior of grazing dairy cows experiencing varying degrees of hypocalcemia and hyperketonemia. To do this, data from 4 separate parent experiments were collated to generate a database containing detailed phenotype data, including, but not limited to, measures of cow performance (e.g., milk production and composition, body weight and body condition score), cow health (e.g., energy and protein metabolites, minerals, liver enzymes, and immune markers in blood), and cow behavior (e.g., lying behavior and activity derived from triaxial accelerometers). My review of the appropriate use of leg-mounted accelerometers to monitor lying behaviors of dairy cows indicated that applying editing criteria to remove errors in lying behavior data caused by erroneous movements of the leg (e.g., scratching and kicking) can improve the accuracy of data derived from accelerometers for recording daily lying bouts (LB); however, has little to no impact on the accuracy of lying time. Lying behavior data must be edited using a suitable LB criterion where the interest is in studying both lying time and LB. My results indicated that inclement weather, parity, and physiological state are important variables that influence behavior in their own right and must be considered in subsequent analyses. Interestingly, when comparing my results with lying behaviors previously reported in housed cows, my results indicated that grazing dairy cows engage in similar lying behaviors to housed cows before and at the time of calving, while postcalving, grazing cows spend less time lying. Furthermore, grazing dairy cows displayed greater behavioral synchrony (i.e., cows engaged in the same behaviors simultaneously) compared with reports in housed cows. These postcalving differences highlight the importance of assessing behavior within the farming system of interest. My results also indicated that cows alter their behavior in response to ill health, whereby grazing dairy cows experiencing clinical hypocalcemia (without paresis) and hyperketonemia [with severe negative energy balance (NEB)] altered their behavior before, at the time of, and after disease diagnosis compared with healthy cows. My results indicated that behavioral differences between cows classified into 3 blood calcium groups [clinically-hypocalcemic (without paresis), subclinically-hypocalcemic, and normocalcemic] were transient. On the day of calving, clinically-hypocalcemic cows (without paresis), were less active, spent more time lying, and had more frequent LB compared with subclinically-hypocalcemic and normocalcemic cows; however, changes in behavior were short lived and were no longer present by 2 d postcalving. My results indicate that observed differences in behavior associated with hypocalcemia are small and may not be biologically significant as a metric to discriminate between hypocalcemic and normocalcemic cows. On the contrary, changes in behavior over time and within cow may allow differences between hypocalcemic and normocalcemic cows to be more easily discerned than using mean values of lying behavior and activity at a specific time point. My findings indicated that a relative increase in the number of steps taken within cow compared with a baseline period 2 wk precalving was positively associated with blood calcium concentrations postcalving. Further, my results indicated the behavioral differences between cows classified into 3 energy status groups [Hi–Hi = high non-esterified fatty acids (NEFA) and high β-hydroxybutyrate (BHB); Hi–Lo = high NEFA and low BHB, and; Lo–Lo = low NEFA and low BHB] occurred up to 2 wk before calving. During the 2 wk before calving, cows identified as Hi–Hi were more active, spent less time lying, and had fewer LB than the other 2 energy status groups. Interestingly, similar to the hypocalcemia work, my results indicated that a relative increase in the number of steps taken within cow during the 2 wk before calving was associated with lower odds of developing hyperketonemia with NEB; therefore, greater increases in activity before calving were associated with improved health outcomes postcalving in both studies. My results suggest that relative changes in behavior, in particular, step activity, might be an improved metric to discriminate between clinically-healthy grazing cows and cows experiencing a subclinical metabolic disease. My research provides an improved understanding of the associations between cow behavior and health, particularly for grazing dairy cows. This information provides a base for further exploring the potential for behavior and activity measures to identify cows experiencing ill health during the transition period. Future work should focus on continuing to improve our understanding of associations between behavior and disease, particularly in grazing dairy cows. Using within-cow behavior measures and determining how these data could be interpreted so that farmers could be alerted to sick animals and make actionable decisions on farm, should be the focus of future studies

Association of rare MSH6 variants with familial breast cancer

Germline mutations in the mismatch repair genes MLH1, MSH2, MSH6, and PMS2 predispose to Lynch syndrome (also known as hereditary non-polyposis colorectal cancer). Recently, we have shown that the CHEK2 1100delC mutation also is associated with Lynch syndrome/Lynch syndrome-associated families albeit in a polygenic setting. Two of the ten CHEK2 1100delC positive Lynch syndrome families additionally carried a pathogenic MLH1 or MSH6 mutation, suggesting that mutations in mismatch repair genes may be involved in CHEK2 1100delC-associated cancer phenotypes. A phenotype of importance is hereditary breast and colorectal cancer (HBCC), with the CHEK2 1100delC mutation present in almost one-fifth of the families-again in a polygenic setting. In order to evaluate the involvement of MSH6 in polygenic CHEK2 cancer susceptibility, we, here, have analyzed the entire MSH6 coding sequence for genetic alterations in 68 HBCC breast cancer families. Rare MSH6 variants, with population frequencies below 1%, were identified in 11.8% of HBCC breast cancer families, whereas the same variants were identified in only 1.5% of population controls, suggesting that rare MSH6 variants are associated with HBCC breast cancer (P <or = 0.00001). However, screening of the entire MSH6 coding sequence in 68 non-HBCC breast cancer families showed a similar association (8.8 vs. approximately 1.4% in controls, P <or = 0.001), suggesting that rare MSH6 variants are not confined to HBCC breast cancer. Together, our data suggest that rare MSH6 variants may predispose to familial breast cancer. However, none of the rare MSH6 variants are obviously pathogenic, suggesting that a more subtle disease mechanism may operate in breast carcinogenesi

2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS.

Peer reviewe

The effect of prepartum synthetic zeolite supplementation on the eating, lying and activity behaviours of grazing dairy cows

This study determined the effect of feeding synthetic zeolite A prepartum to reduce periparturient hypocalcaemia risk on the eating, lying, and activity behaviours of multiparous grazing dairy cows. Animals were randomly allocated to either a Zeolite treatment group (n = 21; individually fed 500 g/d zeolite for two weeks prepartum) or a Control group (n = 22). Behaviour data obtained from accelerometers were analysed to determine the effects of treatment, parity (Parity 2−3 vs. 4+), and their interactions during 3 periods: PRE (−21 to −3 d), PERI (−2–2 d) and POST (3–28 d) relative to the day of calving (day 0). Parity 2–3 Zeolite cows ate for 18 min/day less than Parity 2–3 Control cows PRE. Zeolite-fed cows also ate for 24 min/day less than Control cows during the PERI period. There were no treatment differences in lying time or activity PRE or PERI, but Zeolite-fed cows spent more time lying POST. Regardless of treatment, Parity 2–3 cows were generally more active and ate for longer than Parity 4 + cows. Our results suggest zeolite may subtly decrease appetite or alter eating behaviour during the supplementation period, particularly in younger cows, and may improve cow comfort postcalving.</p

A Clinical Guide for Assessment and Prescription of Exercise and Physical Activity in Cardiac Rehabilitation. A CSANZ Position Statement

Patients with cardiovascular disease benefit from cardiac rehabilitation, which includes structured exercise and physical activity as core components. This position statement provides pragmatic, evidence-based guidance for the assessment and prescription of exercise and physical activity for cardiac rehabilitation clinicians, recognising the latest international guidelines, scientific evidence and the increasing use of technology and virtual delivery methods. The patient-centred assessment and prescription of aerobic exercise, resistance exercise and physical activity have been addressed, including progression and safety considerations.</p

A high-yield double-purification proteomics strategy for the identification of SUMO sites

Cancer Signaling networks and Molecular Therapeutic

Multilineage co-culture of adipose-derived stem cells for tissue engineering

© 2012 John Wiley & Sons, Ltd. Stem cell interactions through paracrine cell signalling can regulate a range of cell responses, including metabolic activity, proliferation and differentiation. Moving towards the development of optimized tissue-engineering strategies with adipose-derived stem cells (ASCs), the focus of this study was on developing indirect co-culture models to study the effects of mature adipocytes, chondrocytes and osteoblasts on bovine ASC multilineage differentiation. For each lineage, ASC differentiation was characterized by histology, gene expression and protein expression, in the absence of key inductive differentiation factors for the ASCs. Co-culture with each of the mature cell populations was shown to successfully induce or enhance lineage-specific differentiation of the ASCs. In general, a more homogeneous but lower-level differentiation response was observed in co-culture as compared to stimulating the bovine ASCs with inductive differentiation media. To explore the role of the Wnt canonical and non-canonical signalling pathways within the model systems, the effects of the Wnt inhibitors WIF-1 and DKK-1 on multilineage differentiation in co-culture were assessed. The data indicated that Wnt signalling may play a role in mediating ASC differentiation in co-culture with the mature cell populations

Business strategies for transitions to sustainable systems

This paper develops a strategic perspective for business to contribute to the innovation of societal systems. Sustainability issues at the level of societal sectors cannot be addressed by single organizations but need to be thought of as systemic challenges in which business, government and civil society each play different roles. Sustainability involves structural changes over longer periods of time, and requires co-evolutionary changes in technology, economy, culture and organizational forms. We propose that the transition management framework offers a fruitful way to analyze such co-evolutionary processes of social transformation and subsequently develop strategies to infl uence and accelerate such processes. We present the case of two firms working in this new context of transition management in The Netherlands. From these cases we conceptualize a more general approach for business to redefine and reframe the societal context in which it is operating and develop novel business strategies