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Some observations on the behaviour of lake-dwelling brown trout in Lower Lough Erne
No full textPublication history: Accepted - 11 January 2021; Published online - 23 February 2021.Acoustic telemetry was utilised to track a sample of 80 adult wild brown trout across an extensive array of 30 receivers in Lower Lough Erne during 2016 and 2017. The mean detection duration across the array was 142 days, and the majority of tagged fish were detected consistently in the northern basin of the lake. One year after tagging, c.40% of larger fish (>45cm LF) were still actively detected, while only 5-10% of smaller fish (50%) did not undertake spawning migrations into an influent tributary and remained active within the lake during the reproductive period in November. In total, fourteen tagged trout undertook spawning migrations into a range of tributaries; the mean spawning sojourn was 54 days, and five fish (36%) did not return to the lake post spawning
Laser methane detector-based quantification of methane emissions from indoor-fed Fogera dairy cows
Get PDFPublication history: Accepted - 14 December 2020; Published online - 1 January 2021.Objective: Portable laser methane detectors (LMDs) may be an economical means of
estimating CH4 emissions from ruminants. We validated an LMD-based approach and
then used that approach to evaluate CH4 emissions from indigenous dairy cows in a dryland
area of Ethiopia.
Methods: First, we validated our LMD-based approach in Simmental crossbred beef cattle
(n = 2) housed in respiration chambers and fed either a high- or low-concentrate diet. From
the results of the validation, we constructed an estimation equation to determine CH4
emissions from LMD CH4 concentrations. Next, we used our validated LMD approach to
examine CH4 emissions in Fogera dairy cows grazed for 8 h/d (GG, n = 4), fed indoors on
natural-grassland hay (CG1, n = 4), or fed indoors on Napier-grass (Pennisetum purpureum)
hay (CG2, n = 4). All the cows were supplemented with concentrate feed.
Results: The exhaled CH4 concentrations measured by LMD were linearly correlated with
the CH4 emissions determined by infrared-absorption-based gas analyzer (r
2
= 0.55). The
estimation equation used to determine CH4 emissions (y, mg/min) from LMD CH4 concentrations (x, ppm m) was y = 0.4259x+38.61. Daily CH4 emissions of Fogera cows estimated
by using the equation did not differ among the three groups; however, a numerically greater
milk yield was obtained from the CG2 cows than from the GG cows, suggesting that Napiergrass hay might be better than natural-grassland hay for indoor feeding. The CG1 cows had
higher CH4 emissions per feed intake than the other groups, without significant increases
in milk yield and body-weight gain, suggesting that natural-grassland hay cannot be recommended for indoor-fed cows.
Conclusion: These findings demonstrate the potential of using LMDs to valuate feeding
regimens rapidly and economically for dairy cows in areas under financial constraint, while
taking CH4 emissions into consideration.We acknowledge the support of the Andassa Livestock Research Center, Amhara Region Agricultural Research Institute, Ethiopia, and the College of Grassland Science of Lanzhou University, China, for providing the respiration chambers (registered as LZUCKY-S-DXCLZ-001 for Institute of Grassland and Livestock Production System, Lanzhou University). This study was supported by the Marginal Region Agriculture Project of Tottori University; the Science and Technology Research Partnership for Sustainable Development (SATREPS) Project for Development of Next-generation Sustainable Land Management (SLM) Framework to Combat Desertification (JPMJSA1601) of the Japan Science and Technology Agency and Japan International Cooperation Agency; the Strategic Priority Research Program of Chinese Academy of Science (XDA20100102); the Key R & D Program of Ningxia Hui Autonomous Region (2019BBF02001); and the Program for Changjiang Scholars and Innovative Research Team at the University of China (IRT17R50)
Refining Fisheries Advice With Stock-Specific Ecosystem Information
Get PDFPublication history: Accepted - 17 March 2021; Published - 9 April 2021.Although frequently suggested as a goal for ecosystem-based fisheries management,
incorporating ecosystem information into fisheries stock assessments has proven
challenging. The uncertainty of input data, coupled with the structural uncertainty of
complex multi-species models, currently makes the use of absolute values from such
models contentious for short-term single-species fisheries management advice. Here,
we propose a different approach where the standard assessment methodologies can
be enhanced using ecosystem model derived information. Using a case study of the
Irish Sea, we illustrate how stock-specific ecosystem indicators can be used to set
an ecosystem-based fishing mortality reference point (FECO) within the “Pretty Good
Yield” ranges for fishing mortality which form the present precautionary approach
adopted in Europe by the International Council for the Exploration of the Sea (ICES). We
propose that this new target, FECO, can be used to scale fishing mortality down when
the ecosystem conditions for the stock are poor and up when conditions are good.
This approach provides a streamlined quantitative way of incorporating ecosystem
information into catch advice and provides an opportunity to operationalize ecosystem
models and empirical indicators, while retaining the integrity of current assessment
models and the FMSY -based advice process.This project (Grant-Aid Agreement No. CF/16/08) was carried
out with the support of the Marine Institute and funded under
the Marine Research Sub-programme by the Irish Government
Revisiting the Relationships between Fat-to-Protein Ratio in Milk and Energy Balance in Dairy Cows of Different Parities, and at Different Stages of Lactation
Get PDFPublication history: Accepted - 12 November 2021; Published - 14 November 2021.Simple Summary
Data from 840 Holstein-Friesian cows (1321 lactations) were used to evaluate trends in fat-to-protein ratios in milk (FPR), and the use of FPR as an indicator of energy balance (EB). The fat-to-protein ratio was negatively related to EB, and this relationship became more negative with increased parity. Regression slopes describing linear relationships between FPR and EB differed over time, although trends were inconsistent. Similarly, ‘High’ FPR scores in milk (≥1.5) were consistently associated with a greater negative energy balance, milk yields, body weight loss, and plasma non-esterified fatty acid concentrations; however, their relationships with dry matter intake did not follow a clear trend. Although FPR can provide an indication of EB at a herd level, this analysis suggests that FPR cannot accurately predict the EB of individual cows.
Abstract
A statistical re-assessment of aggregated individual cow data was conducted to examine trends in fat-to-protein ratio in milk (FPR), and relationships between FPR and energy balance (EB, MJ of ME/day) in Holstein-Friesian dairy cows of different parities, and at different stages of lactation. The data were collected from 27 long-term production trials conducted between 1996 and 2016 at the Agri-Food and Biosciences Institute (AFBI) in Hillsborough, Northern Ireland. In total, 1321 lactations (1 to 20 weeks in milk; WIM), derived from 840 individual cows fed mainly grass silage-based diets, were included in the analysis. The energy balance was calculated daily and then averaged weekly for statistical analyses. Data were further split in 4 wk. intervals, namely, 1–4, 5–8, 9–12, 13–16, and 17–20 WIM, and both partial correlations and linear regressions (mixed models) established between the mean FPR and EB during these periods. Three FPR score categories (‘Low’ FPR, 1.5) were adopted and the performance and EB indicators within each category were compared. As expected, multiparous cows experienced a greater negative EB compared to primiparous cows, due to their higher milk production relative to DMI. Relatively minor differences in milk fat and protein content resulted in large differences in FPR curves. Second lactation cows displayed the lowest weekly FPR, and this trend was aligned with smaller BW losses and lower concentrations of non-esterified fatty acids (NEFA) until at least 8 WIM. Partial correlations between FPR and EB were negative, and ‘greatest’ in early lactation (1–4 WIM; r = −0.38 on average), and gradually decreased as lactation progressed across all parities (17–20 WIM; r = −0.14 on average). With increasing parity, daily EB values tended to become more negative per unit of FPR. In primiparous cows, regression slopes between FPR and EB differed between 1–4 and 5–8 WIM (−54.6 vs. −47.5 MJ of ME/day), while differences in second lactation cows tended towards significance (−57.2 vs. −64.4 MJ of ME/day). Irrespective of the lactation number, after 9–12 WIM, there was a consistent trend for the slope of the linear relationships between FPR and EB to decrease as lactation progressed, with this likely reflecting the decreasing milk nutrient demands of the growing calf. The incidence of ‘High’ FPR scores was greatest during 1–4 WIM, and decreased as lactation progressed. ‘High’ FPR scores were associated with increased energy-corrected milk (ECM) yields across all parities and stages of lactation, and with smaller BW gains and increasing concentrations (log transformed) of blood metabolites (non-esterified fatty acid, NEFA; beta-hydroxybutyrate, BHB) until 8 WIM. Results from the present study highlight the strong relationships between FPR in milk, physiological changes, and EB profiles during early lactation. However, while FPR can provide an indication of EB at a herd level, the large cow-to-cow variation indicates that FPR cannot be used as a robust indicator of EB at an individual cow level.The interaction between genotype and nutrition in high yielding dairy cows in seasonal
grass-based systems of milk production (NutriGen project) was funded by the Department of Agriculture,
Food and the Marine (Republic of Ireland) and the Department of Agriculture, Environment
and Rural Affairs (Northern Ireland) under funding agreement 15/S/675
Various Statistical Approaches to Assess and Predict Carcass and Meat Quality Traits
Get PDFPublication history: Accepted - 8 April 2020; Published - 22 April 2020.The beef industry is organized around di erent stakeholders, each with their own
expectations, sometimes antagonistic. This article first outlines these di ering perspectives. Then,
various optimization models that might integrate all these expectations are described. The final goal
is to define practices that could increase value for animal production, carcasses and meat whilst
simultaneously meeting the main expectations of the beef industry. Di erent models previously
developed worldwide are proposed here. Two new computational methodologies that allow the
simultaneous selection of the best regression models and the most interesting covariates to predict
carcass and/or meat quality are developed. Then, a method of variable clustering is explained that
is accurate in evaluating the interrelationships between di erent parameters of interest. Finally,
some principles for the management of quality trade-o s are presented and the Meat Standards
Australia model is discussed. The “Pareto front” is an interesting approach to deal jointly with the
di erent sets of expectations and to propose a method that could optimize all expectations togethe
The state of the world’s urban ecosystems: What can we learn from trees, fungi, and bees?
Get PDFPublication history: Accepted - 2 July 2020; Published online - 29 September 2020Trees are a foundation for biodiversity in urban ecosystems and therefore must be able to withstand global change and biological challenges over decades and even centuries to prevent urban ecosystems from deteriorating. Tree quality and diversity should be prioritized over simply numbers to optimize resilience to these challenges. Successful establishment and renewal of trees in cities must also consider belowground (e.g., mycorrhizas) and aboveground (e.g., pollinators) interactions to ensure urban ecosystem longevity, biodiversity conservation and continued provision of the full range of ecosystem services provided by trees. Positive interactions with nature inspire people to live more sustainable lifestyles that are consistent with stopping biodiversity loss and to participate in conservation actions such as tree‐planting and supporting pollinators. Interacting with nature simultaneously provides mental and physical health benefits to people. Since most people live in cities, here we argue that urban ecosystems provide important opportunities for increasing engagement with nature and educating people about biodiversity conservation. While advocacy on biodiversity must communicate in language that is relevant to a diverse audience, over‐simplified messaging, may result in unintended negative outcomes. For example, tree planting actions typically focus on numbers rather than diversity while the call to save bees has inspired unsustainable proliferation of urban beekeeping that may damage wild bee conservation through increased competition for limited forage in cities and disease spread. Ultimately multiple ecosystem services must be considered (and measured) to optimize their delivery in urban ecosystems and messaging to promote the value of nature in cities must be made widely available and more clearly defined.Animal Plant Health Agency (UK). Grant Number: 88566670
Phosphorus stocks and flows in an intensive livestock dominated food system
Get PDFPublication history: Accepted - 21 July 2020; Published online - 31 July 2020.Current use and management of phosphorus (P) in our food systems is considered unsustainable and considerable
improvements in the efficiency of P use are required to mitigate the environmental impact of poor P
stewardship. The inherent low P use efficiency of food production from animals means food systems dominated
by livestock agriculture can pose unique challenges for improving P management. This paper presents the results
of a substance flow analysis for P in the Northern Ireland (NI) food system for the year 2017 as a case study for
examining P stewardship in a livestock dominated agricultural system. Imported livestock feed was by far the
largest flow of P into the NI food system in 2017 (11,700 t ± 1300 t) and P from livestock excreta the largest
internal flow of P (20,400 ± 1900t). The P contained in livestock slurries and manures alone that were returned
to agricultural land exceeded total crop and grass P requirement by 20% and were the largest contributor to an
annual excess soil P accumulation of 8.5 ± 1.4 kg ha−1. This current livestock driven P surplus also limits the
opportunities for P circularity and reuse from other sectors within the food system, e.g. wastewater biosolids and
products from food processing waste. Management of livestock P demand (livestock numbers, feed P content) or
technological advancements that facilitate the processing and subsequent export of slurries and manures are
therefore needed.This paper was produced as part of the RePhoKUs project (The role
of phosphorus in the sustainability and resilience of the UK food
system) funded by BBSRC, ESRC, NERC, and the Scottish Government
under the UK Global Food Security research programme. Funding was
provided by Biotechnology and Biological Sciences Research Council
(Grant No. BB/R005842/1)
Understanding the drivers and motivations of farm diversification: Evidence from Northern Ireland using a mixed methods approach
Get PDFPublication history: Accepted - 28 October;Farmers are increasingly required to become more productive and innovative to ensure effective 9 management of farm resources and to improve their livelihoods. Farm diversification has been 10 identified as a viable strategy that can be adopted by farm businesses to achieve these objectives 11 in order to reduce their reliance on agricultural production as the main source of household 12 income. In this study, we employ a mixed methods approach to analyse the factors influencing 13 farm diversification and diversification strategies in Northern Ireland. The challenges of setting 14 up a farm diversification enterprise were also explored. Data collection and analysis were 15 undertaken by combining both quantitative and qualitative approaches in a two-stage process 16 using primary data obtained from a survey of farm businesses and interviews with key 17 stakeholders involved in the Northern Ireland agricultural sector. The study results show that the 18 primary motivating factor in pursuing farm-level diversification is the need to generate additional 19 income. The analysis has shown that farm level diversification has the capacity to contribute to 20 both the sustainability of family farms and the wider rural economy. The study results support 21 the need for governments to explore the development of policy measures to support 22 diversification at farm level
Northern Ireland farm-level management factors for prolonged bovine tuberculosis herd breakdowns.
Get PDFPublication history: Accepted - 16 September 2020; Published online - 28 September 2020This study determined farm management factors associated with long-duration bovine tuberculosis (bTB) breakdowns disclosed in the period 23 May 2016 to 21 May 2018; a study area not previously subject to investigation in Northern Ireland. A farm-level epidemiological investigation (n = 2935) was completed when one or more Single Intradermal Comparative Cervical Test (SICCT) reactors or when one or more confirmed (positive histological and/or bacteriological result) lesion at routine slaughter were disclosed. A case-control study design was used to construct an explanatory set of management factors associated with long-duration bTB herd breakdowns; with a case (n = 191) defined as an investigation into a breakdown of 365 days or longer. Purchase of infected animal(s) had the strongest association as the most likely source of infection for long-duration bTB herd breakdowns followed by badgers and then cattle-to-cattle contiguous herd spread. However, 73.5% (95% CI 61.1–85.9%) of the herd type contributing to the purchase of infection source were defined as beef fattening herds. This result demonstrates two subpopulations of prolonged bTB breakdowns, the first being beef fattening herds with main source continuous purchase of infected animals and a second group of primary production herds (dairy, beef cows and mixed) with risk from multiple sources
The Effect of Beef Production System on the Health, Performance, Carcass Characteristics, and Meat Quality of Holstein Bulls
Get PDFPublication history: Accepted - 17 October 2020; Published online - 19 October 2020.The aim of this study was to evaluate the e ect of production system on the health,
performance, carcass characteristics, and meat quality of autumn born (AB) and spring born (SB)
Holstein bulls. The study involved a total of 224 Holstein bulls and was conducted over two years
(2017/18, 2018/19). The four production system treatments di ered during the grower period and
consisted of: (i) grazed with no concentrate supplementation (G), (ii) grazed with 2 kg concentrate
supplementation per day (G2), (iii) grazed with ad libitum access to concentrates (GA) and (iv)
housed with ad libitum access to concentrates and grass silage (HA). All bulls were finished on ad
libitum concentrates and grass silage and were slaughtered at a mean age of 15.5 months. Total
grower dry matter intake (DMI) (p < 0.001) and total finishing DMI (p < 0.001) di ered between
production systems for both AB and SB bulls, with that of GA bulls being the greatest in both cases.
Average daily gain (ADG) during the grower period was greatest (p < 0.001) for the HA production
system in the AB bulls and the GA and HA production systems for the SB bulls. However, during
the finishing period, G bulls had the greatest (p < 0.001) ADG of the AB bulls, while that of the SB
bulls was from the G2 production system (p < 0.001). For both AB and SB, bulls on the GA and
HA production systems produced heavier cold carcass weights than the G and G2 bulls (p < 0.001).
There was no significant di erence (p > 0.05) in health, carcass conformation, fat classification, or
meat quality between production systems.This study was jointly funded by the Department of Agriculture, Environment and Rural Affairs for
Northern Ireland and AgriSearchNI