Effect of climate variability on pasture-based dairy feeding systems in south-east Australia

2015 ◽  
Vol 55 (9) ◽  
pp. 1106 ◽  
Author(s):  
Şeyda Özkan ◽  
Julian Hill ◽  
Brendan Cullen

The Australian dairy industry relies primarily on pasture for its feed supply. However, the variability in climate affects plant growth, leading to uncertainty in dryland pasture supply. This paper models the impact of climate variability on pasture production and examines the potential of two pasture-based dairy feeding systems: (1) to experience winter deficits; (2) to carry forward the conserved pasture surpluses as silage for future use; and (3) to conserve pasture surpluses as hay. The two dairy feeding systems examined were a traditional perennial ryegrass-based feeding system (ryegrass max. – RM) and a system that incorporated double cropping into the perennial ryegrass pasture base (complementary forage – CF). The conditional probability of the RM and CF systems to generate pasture deficits in winter were 94% and 96%, respectively. Both systems could carry forward the surplus silage into the following lactation almost once in every 4–5 years with the RM system performing slightly better than the CF system. The proportions of the grain-based concentrates fed in the two systems were 25% and 27% for the RM and CF systems, respectively. This study suggests that double-cropping systems have the potential to provide high-quality feed to support the feed gaps when pasture is not available due to increased variability in climatic conditions.


2006 ◽  
Vol 46 (8) ◽  
pp. 993 ◽  
Author(s):  
S. M. Robertson

The impact of different management strategies on production and profit can be evaluated with knowledge of how sheep production responds to changes in the available feed base and sheep or pasture management. This study aimed to quantify on-farm pasture and sheep production in mixed sheep and cropping systems in the Victorian Mallee of south-eastern Australia (325 ± 50 mm annual rainfall) as a prelude to computer simulation modelling. During 2001 (average rainfall) and 2002 (extreme drought) pasture production, the feed base and sheep production were monitored in 15 paddocks on 5 properties located across the region. Crop stubbles were the major source of feed for 6 months of the year, enabling ewes to maintain liveweight. There was more variation in pasture parameters between paddocks at the 1 location than between locations. The botanical composition, plant density, soil fertility and management were key variables associated with between-paddock variation in pasture production. Variation in pasture production between years was larger than within-year differences. In contrast, stocking rates were not much lower in the drought year of 2002 than in 2001. This study suggests there is potential for management to improve pasture production, and demonstrates the importance of feed sources other than annual pasture for sheep production in environments where the annual pasture growing season is short.



2022 ◽  
Vol 951 (1) ◽  
pp. 012023
Author(s):  
D Anzhany ◽  
Despal ◽  
T Toharmat ◽  
N Rofiah ◽  
N Nuraina ◽  
...  

Abstract Fatty acids (FA) profiles especially conjugated linoleic acid (CLA) are commonly used to distinguish milk quality. However, its content is very sensitive and tends to change with a different type of feed. The study aims to identify the relationship between the feeding system and milk FA profile in the Pangalengan sub-district. The feeding system and milk FA profiles were studied using two-step post observatory research. Step one, milk was collected from 27 traditional-dairy farms using purposive random sampling and compare with a large-scale farm. The result shows that FA profiles vary greatly among traditional-farms especially for long-chain FA (LCFA) which was found in small concentrations. CLA content was also found higher in traditional-farms. Step two, five traditional-farms with the highest CLA milk content were observed for their feeding systems. Parameter observed including cow’s specification, feed type used, and feed intake. The best ration produced high milk CLA and production was the ration consisted of 38 % high-quality forages and 62 % commercial concentrate. Thus, it can be concluded that milk from traditional farms was better than milk from large-scale farms. The best milk CLA was produced with a combination of 38 % high-quality forages and 62 % commercial concentrate.



1997 ◽  
Vol 37 (5) ◽  
pp. 537 ◽  
Author(s):  
D. J. Donaghy ◽  
J. M. Scott ◽  
W. J. Fulkerson

Summary. The present study investigated, in a subtropical environment, the timing of defoliation treatments in spring and summer irrigation management on the survival of perennial (Lolium perenne cv. Yatsyn) and biennial (L. multiflorum cv. Noble) ryegrass in a mixed ryegrass–white clover (Trifolium repens) pasture over the first summer, and seedling recruitment the following autumn. Defoliation options were related to various ryegrass plant development stages such as the number of leaves per tiller attained during regrowth, stem elongation and seed set. The criterion for timing of frequent defoliation was 1 leaf/tiller regrowth and infrequent defoliation 3 leaves/tiller. Both pasture types were defoliated either frequently or infrequently at specific times from sowing to mid summer. Half the plots were irrigated from 30 November to 6 April while the remaining plots were not irrigated over this period. There was no survival of biennial ryegrass plants into autumn of the second year and pasture production was entirely from seedling recruitment of seed set in the previous spring. The maximum seedling recruitment (plant population 89% of spring in establishment year) was achieved by infrequent defoliation in mid spring and then cessation of defoliation until mid summer to allow plants to set seed. However, this resulted in a production loss of 3094 kg dry matter/ha of ryegrass and clover. In contrast, production of perennial ryegrass in the second year was reliant almost exclusively on individual ryegrass plants surviving the summer, as there was little seed set and virtually no seedling recruitment. There would appear to be 2 contrasting defoliation requirements to optimise perennial ryegrass persistence. Infrequent defoliation from sowing to early spring (22 March–2 September) and frequent defoliation in early summer (19 November–3 February) resulted in maximum plant survival and minimum tropical grass incursion. Frequent, compared with infrequent, defoliation up to 2 September decreased root dry matter in February by 45% to 1.66 g dry matter/plant. However in early summer, frequent defoliation maximised survival, presumably by reducing shading by tropical grasses, and preventing a closed canopy which encourages ‘rust’ infestation of the ryegrass. Irrigation of ryegrass over summer, in situations likely to become waterlogged, will only be of benefit in dry years and if scheduling is frequent enough to benefit ryegrass rather than tropical grass. These results highlight the importance of maintaining an infrequent defoliation interval to maximise persistence of perennial ryegrass in the subtropics. More frequent defoliation may be necessary in late spring/early summer to reduce the impact of leaf rust.



2013 ◽  
Vol 10 (4) ◽  
pp. 4397-4437 ◽  
Author(s):  
Y. Zhou ◽  
Y. Zhang ◽  
J. Vaze ◽  
P. Lane ◽  
S. Xu

Abstract. Most of the surface water for natural environmental and human water uses in southeast Australia is sourced from forested catchments located in the higher rainfall areas. Water yield of these catchments is mainly affected by climatic conditions, but it is also greatly affected by vegetation cover change. Bushfires are a major natural disturbance in forested catchments and potentially modify the water yield of the catchments through changes to evapotranspiration (ET), interception and soil moisture storage. This paper quantifies the impacts of bushfire and climate variability on streamflow from three southeast Australian catchments where Ash Wednesday bushfires occurred in February 1983. The hydrological models used here include AWRA-L, Xinanjiang and GR4J. The three models are first calibrated against streamflow data from the pre-bushfire period and they are used to simulate runoff for the post-bushfire period with the calibrated parameters. The difference between the observed and model simulated runoff for the post-bushfire period provides an estimate of the impact of bushfire on streamflow. The hydrological modelling results for the three catchments indicate that there is a substantial increase in streamflow in the first 15 yr after the 1983 bushfires. The increase in streamflow is attributed to initial decreases in ET and interception resulting from the fires, followed by logging activity. After 15 yr, streamflow dynamics are more heavily influenced by climate effects, although some impact from fire and logging regeneration may still occur. It is shown that hydrological models provide reasonable consistent estimates of forest disturbance and climate impacts on streamflow for the three catchments. The results might be used by forest managers to understand the relationship between forest disturbance and climate variability impacts on water yield in the context of climate change.



2021 ◽  
Vol 9 (01) ◽  
pp. 327-337
Author(s):  
Harmel Obami-Ondon ◽  
◽  
Medard Ngouala Mabonzo ◽  
Ngoma Mvoundou Christian ◽  
Bernard Mabiala ◽  
...  

Climate variability, in Africa in general and in the Republic of Congo-Brazzaville in particular, has been widely documented over the past 20 years. However, variables related to rainfall, such as the nine-month rainy seasons, have been very little studied in the Bateke Plateaux zone, which play a major role in regional hydrology. The objective of this study is to investigate the influence of climatic events on seasonal rainfall patterns on the Plateaux Bateke. On the one hand, it involves monitoring the evolution of climatic parameters through the analysis of temperature, relative humidity and rainfall variation. On the other hand, it was a question of comparing the monthly rainfall normals over the period 1987-2016 in order to determine the behaviour of seasonal rainfall patterns in the context of climate variability. The principal component analysis, based on nine (09) variables, highlighted the impact of climate variability on seasonal rainfall patterns. The first principal component (F1) is associated with the factors defining the climatic conditions of the Plateau Bateke. The second main component (F2) does not express clear correlations. Generally speaking, the temperature and relative humidity of the air are factors in the temporal variability of seasonal rainfall regimes on the Plateaux Bateke.



2008 ◽  
Vol 56 (3) ◽  
pp. 303-312 ◽  
Author(s):  
U. Sangakkara ◽  
P. Stamp

Improved fallows are considered an easy, low cost and suitable method of increasing the productivity and sustainability of smallholder tropical rainfed cropping systems, although most farmers allow weeds to grow when the environmental conditions are not conductive for crop production. Field studies were carried out over the minor and major seasons, to evaluate the impact of a preceding improved fallow using Crotalaria or Tithonia , two popular tropical green manures, on selected soil properties, and on the growth and yield of maize. Improved fallows enhanced chemical soil properties significantly and the impact was most prominent at the onset of the minor maize season. Thus, the growth and yield of maize was also increased to a greater extent in this season, when yields are generally lower due to the suboptimal climatic conditions of lower rainfall and higher temperatures. However, fallows in the minor season also improved soil characteristics and maize yields in the major season, the most significant impact being increased seed yields and harvest indices. Although farmers may not grow fallow crops in major seasons, the potential of these green manure fallows in increasing maize yields in minor seasons and possible strategies to include the fallows in the cropping sequences of tropical rainfed upland cropping systems are discussed on the basis of this field study.



Climate ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 145
Author(s):  
Godwin P. Cudjoe ◽  
Phillip Antwi-Agyei ◽  
Benjamin A. Gyampoh

Agriculture is one of the sectors most susceptible to changes in climatic conditions. The impact is even stronger in Africa, where rain-fed agriculture is vital for daily subsistence, but where adaptive capacity is low. It is therefore crucial to increase the understanding of the actual climate change dynamics on agricultural productivity. This study examined the effects of changes in climatic variables such as rainfall and temperature on maize production in the Ejura-Sekyedumase Municipality, Ghana. Regression, chi-square and trend analyses were used to establish the relationship between climate variables (rainfall and temperature) and maize yield in the study area. This was supplemented with participatory household interviews with 120 farmers to understand the perception of farmers on rainfall and temperature patterns. The results from the study respondents and trend analysis show that rainfall is shorter in terms of duration and less predictable, whilst temperature has increased. The findings suggest that the general relationship between rainfall, temperature and maize yield is such that maize yield increased with increasing rainfall of the right amount and distribution pattern and decreased with increasing temperature. The study concludes that climate variability and/or change is evident in the study area and its effect on maize yield is severe.



Foods ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 137 ◽  
Author(s):  
Tom F. O’Callaghan ◽  
David Mannion ◽  
Diana Apopei ◽  
Noel A. McCarthy ◽  
Sean A. Hogan ◽  
...  

The purpose of this study was to examine the impact of a variety of supplemental feeds on the composition and quality of milk in a pasture-based dairy system. Four pasture-supplemented feeding systems were compared: Group 1 supplementation with 16% crude protein parlour concentrate (CONC); Group 2 supplementation with palm kernel expeller plus parlour concentrate (PKE); Group 3 supplemented with soya hulls plus parlour concentrate (SOYA); Group 4 was supplemented with molassed beet pulp plus parlour concentrate (BEET). Supplemental feeding system was demonstrated to have a significant effect on the size of native casein micelles and the gelation properties of milks. While CONC feeding produced significantly higher casein micelle size, gel strength (Young’s Modulus) was significantly negatively correlated with casein micelle size. Supplemental feeding system had a significant effect on a number of fatty acids (FA) and indices derived therefrom, including total saturated and unsaturated fatty acids, de novo produced FA, omega 3, and omega 6 FA. The volatile profile of milks was also affected by supplemental feed choice, whereby multivariate analysis demonstrated that the CONC diet was distinctly different to that of the PALM, SOYA, and BEET milks. Multivariate analysis demonstrated that it is possible to distinguish milks from different pasture-supplemented feeding systems by their FA profile.



2020 ◽  
pp. 155-164
Author(s):  
Viktor Trokhaniak ◽  
Ivan Rogovskii ◽  
Luidmyla Titova ◽  
Zoriana Dziubata ◽  
Petro Luzan ◽  
...  

Exposure and the outbreak of diseases result in significant losses in large scale poultry operation. New ventilation systems are necessary to provide safe and homogenous internal environment at large enterprises, especially under the changeable climatic conditions of global warming. Within the framework of this investigation, computational fluid dynamics (CFD) simulation of a side ventilation system in a poultry house during winter seasons has been conducted. As results, 3D temperature fields, current lines and pressures in a poultry house have been found. It has been determined that fresh air valves arranged at a height of 200 mm from flooring work better than those traditionally arranged at a height of 400 mm. The erection of walls on the inside of a poultry house framework as well as the decrease in the height of flooring improve poultry house aerodynamics.



Author(s):  
K.N. Tozer ◽  
G.M. Rennie ◽  
W.M. King ◽  
N.R. Mapp ◽  
N.L. Bell ◽  
...  

The impact of renewal on pasture production was determined by monitoring renewed and unrenewed pastures on five farms in each of Bay of Plenty and Waikato for 3 years, excluding the year after sowing (establishment). Renewed pastures produced an additional 1.5 t dry matter (DM)/ha averaged over both regions in the second year after establishment and 1.9 t DM/ha in each of the third and fourth years. Renewed pastures also had greater clover DM content in spring and summer and lower broadleaf weed DM content in winter. Perennial ryegrass tiller densities were similar in renewed and unrenewed pastures in both regions. There were fewer white-fringed weevil, black beetle and total nematodes in renewed pastures on at least one of the sampling times. It was concluded that higher clover content, fewer weeds, and fewer insect pests contributed to greater DM production in renewed pastures. Keywords: Pasture renewal; dairy pastures; pasture persistence; DM production; regrassing



Sign in / Sign up

Export Citation Format

Share Document