Valuing forages for genetic selection: what traits should we focus on?

2015 ◽  
Vol 55 (7) ◽  
pp. 869 ◽  
Author(s):  
D. F. Chapman ◽  
G. R. Edwards ◽  
A. V. Stewart ◽  
M. McEvoy ◽  
M. O'Donovan ◽  
...  
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Nutritive Value ◽  
Production Systems ◽  
Economic Value ◽  
Genetic Selection ◽  
Livestock Production ◽  
Animal Production ◽  
Yield Data ◽  
Feeding Value

Failure over the past two to three decades to implement industry-led, systematic forage evaluation systems that translate forage performance data to animal production and economics means that the livestock industries are poorly positioned to judge how much economic benefit they are gaining from forage plant improvement and to propose future priorities and targets. The present paper identifies several knowledge gaps that must be filled to enable the value being delivered to pasture-based livestock industries by forage improvement to be determined, demonstrated to farmers and increased in the future. Seasonal yield, total annual yield, nutritive value and feeding value of pasture are all important traits for driving the productivity of pasture-based livestock production systems. From a farm systems perspective, persistence of the yield or quality advantage of new cultivars is also economically important. However, this is the least well defined of the productivity traits considered in the paper. Contrary to anecdotal reports, evidence indicates that the genetic potential of modern ryegrass cultivars to survive in grazed pastures is at least equivalent to that of older cultivars. Plant breeding in Europe and New Zealand has changed the seasonal yield, quality and intake potential of perennial ryegrass. On the basis of dry matter (DM) yield data from small-plot evaluation trials, the New Zealand forage value index indicates that the top-ranked perennial ryegrass cultivars offer between NZ$280 and NZ $650/ha per year potential additional operating profit to dairy businesses (depending on region), compared with a historical genetic base of cultivars that were first entered into yield testing programs between 1991 and 1996. The equivalent figure in Ireland (including nutritive value effects) is about €325/ha per year. These estimates are yet to be confirmed in animal production studies. In intensive dairy systems, current rates of genetic gain in DM yield lag well behind realised rates of gain in animal genetics and associated increases in feed demand per animal. Genetic gains in yield need to double from current rates (estimated at 0.5% per year); but, it is not known whether this is possible in an outcrossing species such as perennial ryegrass, which is normally grown in a mixture with other species, especially white clover. Improvements in DM yield in seasons where extra DM has greatest economic value in grazing systems should dominate breeding objectives, but this must now be augmented by consideration of the environmental impacts of intensive pasture-based livestock production systems and opportunities to mitigate this through germplasm selection. There is less evidence that nutritive or feeding value of ryegrass cultivars significantly limits animal production and profitability and useful improvements have already been made using tetraploids and later heading material.

scholarly journals Red Chittagong Cattle: An Indigenous Breed to Help Tackle the Challenges of Modern Animal Production Systems

2021 ◽  
Vol 5 ◽  
Author(s):  
Nani Gopal Das ◽  
Mohammed R. Islam ◽  
Nathu Ram Sarker ◽  
Md. Abdul Jalil ◽  
Cameron E. F. Clark
Keyword(s):  
Milk Protein ◽  
Nutritive Value ◽  
Production Systems ◽  
Genetic Selection ◽  
Reproductive Traits ◽  
Well Being ◽  
Animal Production ◽  
Indigenous Cattle ◽  
Indigenous Breed ◽  
Animal Production Systems

Modern livestock selection is rapidly condensing the indigenous cattle gene pool. This trend limits the options for future genetic selection to benefit both animal well-being and farmer challenges. Here we reveal the potential of Red Chittagong cattle (RCC), a native genotype of Bangladesh, for tackling these current and pending challenges. Red Chittagong cattle are reddish in color and small in size with mature bulls and cows weighing 342 and 180 kg from birth weights of 16 and 14 kg, respectively. Whilst low mean levels of milk production of 618 L across a 228-day lactation are recorded so are high levels of milk protein (3.8%) and fat (4.8%) with offered feed types typically low in nutritive value, particularly crude protein. However, one in five cows under farm condition yield >1,000 L/lactation. Alongside high levels of milk protein and fat, other key features of this breed include resistance to common diseases and parasites with a high level of adaptation to agro-ecological conditions. As opposed to other indigenous breeds, there is currently high genetic variation in the RCC population, and associated variation in productive and reproductive traits highlighting the opportunity for development through long-term breeding programs alongside improved management conditions. Such efforts would enable this breed to become a global resource for tackling the challenges of modern animal production systems. In addition, further work is required to reveal the demographic distribution of the breed, potential production levels through the provision of improved diets and the mechanisms enabling disease resistance and digestibility of feeds.

The economic value to dairy systems of genetic gains in the nutritive value of perennial ryegrass in grass–clover pastures

2017 ◽  
Vol 57 (7) ◽  
pp. 1357 ◽  
Author(s):  
C. M. Wims ◽  
C. I. Ludemann ◽  
H. Phillips ◽  
D. F. Chapman
Keyword(s):  
New Zealand ◽  
Functional Groups ◽  
Perennial Ryegrass ◽  
Nutritive Value ◽  
Economic Value ◽  
Economic Benefits ◽  
Botanical Composition ◽  
Dairy Farmers ◽  
Flowering Behaviour ◽  
Metabolisable Energy

Perennial ryegrass (Lolium perenne L.) breeding efforts have focussed on improving pasture nutritive value by altering flowering behaviour and increasing ploidy. However, the gains in farm profitability that this has delivered are not known. The flowering behaviour, botanical composition and nutritive value of pastures based on 24 perennial ryegrass cultivar–endophyte combinations released in New Zealand since 1970 were compared under grazing for 3 years in the Waikato region of New Zealand. Cultivars were grouped into the following three functional groups for data analysis: mid-season-heading diploids, late- and very late-heading diploids, and late- and very late-heading tetraploids. The first of these groups included older, ‘standard’ cultivars, while the latter two groups were dominated by cultivars released since 2002. The appearance of reproductive tillers in grazed pastures was delayed by 4–8 weeks for the late- and very late-heading cultivars, resulting in pastures that maintained a greater proportion of green leaf and had a greater metabolisable energy (ME) concentration during spring. Tetraploid pastures had a greater ME concentration than did diploid pastures, largely due to the greater ME concentration of the perennial ryegrass component of these pastures. The gains in pasture nutritive value achieved by broadening the range of perennial ryegrass functional types have the potential to deliver economic benefits in the range of NZ$54/ha.year (late-heading diploids compared with mid-heading diploids) to NZ$232/ha.year (tetraploids compared with mid-heading diploids) to New Zealand dairy farmers. Potential economic gains can be diminished by changes in pasture botanical composition both over time and between functional groups.

Perennial ryegrass breeding in New Zealand: A dairy industry perspective

2012 ◽  
Vol 63 (2) ◽  
pp. 107 ◽  
Author(s):  
Julia M. Lee ◽  
Cory Matthew ◽  
Errol R. Thom ◽  
David F. Chapman
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
Genetic Improvement ◽  
Plant Traits ◽  
Dairy Industry ◽  
Animal Production ◽  
Plant Performance ◽  
Breeding Programs ◽  
Improvement Programs ◽  
Pasture Plants

Genetic improvement programs for livestock and pasture plants have been central to the development of the New Zealand (NZ) pastoral industry. Although genetic improvement of livestock is easily shown to improve animal production on-farm, the link between genetic improvement of pasture plants and animal production is less direct. For several reasons, gains in farm output arising from improved plant performance are more difficult to confirm than those arising from livestock improvement, which has led to some debate in the livestock industries about which plant traits to prioritise in future breeding programs to deliver the greatest benefit. This review investigates this situation, with the aim of understanding how genetic improvement of perennial ryegrass (Lolium perenne L.), the predominant pasture grass, may more directly contribute towards increased productivity in the NZ dairy industry. The review focuses on the dairy industry, since it is the largest contributor to the total value of NZ agricultural exports. Also, because rates of pasture renewal are greater in the dairy industry compared with the sheep and beef industries, genetic gain in pasture plants is likely to have the greatest impact if the correct plant traits are targeted. The review highlights that many aspects of ryegrass growth and ecology have been manipulated through breeding, with evidence to show that plant performance has been altered as a result. However, it is not clear to what extent these gains have contributed to the economic development of the NZ dairy industry. There are opportunities for breeders and scientists to work together more closely in defining economic traits that positively influence pasture performance and to translate this information to objectives for breeding programs, systematically linking information on the measured traits of ryegrass cultivars to economic values for those traits to assist farmer decision-making regarding the most appropriate cultivars to use in their farm system, and better defining genotype × environment interactions in key productivity traits of modern ryegrass cultivars. Changes in priorities for investment of public- and industry-good funds in forage improvement research and development will be needed if these opportunities are to be captured.

Evaluation of a long-established silvopastoral Brachiaria decumbens system: plant characteristics and feeding value for cattle

2019 ◽  
Vol 70 (9) ◽  
pp. 814 ◽  
Author(s):  
Marina A. Lima ◽  
Domingos S. C. Paciullo ◽  
Fabyano F. Silva ◽  
Mirton J. F. Morenz ◽  
Carlos A. M. Gomide ◽  
...  
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Nutritive Value ◽  
Production Systems ◽  
Crude Protein Content ◽  
Brachiaria Decumbens ◽  
Dairy Heifers ◽  
Feeding Value ◽  
Signal Grass ◽  
The Difference

One of the main challenges of using a silvopastoral system (SPS) is maintaining pasture and animal productivity over time. Our objective was to compare the productive characteristics and nutritive value of signal grass (Brachiaria decumbens cv. Basilisk) and the liveweight gain of dairy heifers in a SPS and open pasture (OP, signal grass under full sunlight) during the rainy seasons of four experiments between 2003 and 2016, which characterised systems from their 6th to 19th years after establishment in south-eastern Brazil when analysed together. The experimental design was a randomised complete block in a 2 × 4 factorial scheme (two production systems (SPS and OP) and four experiments (2003–2004, 2004–2007, 2011–2014 and 2014–2016)). From the 7th year onwards, the progressive reduction of photosynthetically active radiation negatively impacted the productive characteristics of the SPS pasture. Total forage mass was reduced by 19% in SPS compared with the OP in 2004–2007, 38% in 2011–2014 and 31% in 2014–2016. Crude protein content was 23% and 30% higher in the SPS than in the OP in 2011–2014 and 2014–2016, respectively. However, during the study period (until the 19th year), the liveweight gain of heifers was similar between systems since the higher crude protein content available in SPS contributed to improved forage nutritional value. From the 17th to the 19th year, weight gain per area was lower in the SPS compared with the OP (169 vs 199 kg ha–1), although the difference between systems was small. Signal grass presents a high degree of phenotypic plasticity in response to changes in shade levels, which gives this species a high potential for use in SPS.

Towards improved silage quality – A review

2001 ◽  
Vol 81 (2) ◽  
pp. 157-168 ◽  
Author(s):  
E. Charmley
Keyword(s):  
Volatile Fatty Acids ◽  
Nutritive Value ◽  
Protein Solubility ◽  
Animal Production ◽  
Energy Utilization ◽  
Negative Effects ◽  
Silage Fermentation ◽  
Feeding Value ◽  
Silage Quality ◽  
Voluntary Intake

Silage quality, as with all forages, is governed by the maturity of the crop at harvest. However, fermentation in the silo further influences nutritive value of silage by reducing voluntary intake and utilization of digestible nutrients. Silage research up to the present time has focussed on closing the gap between feeding value of the original crop and that of the resulting silage. This review focuses on the advances made towards closing that gap, and explores the possibility that in the future ensiling can become a tool for actually increasing the feeding value of forages. Following a section defining silage quality, the relationships between silage fermentation quality and voluntary intake and between silage fermentation and protein and energy utilization will be examined, with emphasis placed on measures to minimize the negative effects of fermentation on animal production. Recent literature is reviewed, which suggests that many factors previously thought to reduce silage intake, such as pH, lactic acid and dry matter (DM), have, in fact, only a casual relationship with intake. Concentrations of fermentation acids do not seem closely related to silage intake; however, they are critical in determining the balance of volatile fatty acids (VFA) produced in the rumen. This in turn, affects the non-glucogenic ratio and can influence milk and body composition in productive livestock. While rumen ammonia is often implicated in reducing silage intake, protein solubility may be more the causal agent than ammonia per se. Protein solubility is also a major factor in reducing the efficiency of silage protein utilization. Methods to reduce protein solubility in silages are discussed. Methods shown to improve silage feeding value include effective wilting and rapid acidification, either by direct acidification or the use of inoculants. Their widespread adoption has undoubtedly contributed to improvements in animal production from silages in recent years. Key words: Silage, feeding value, voluntary food intake, fermentation, ruminant

Impact of dicyandiamide application on nitrous oxide emissions from urine patches in northern Victoria, Australia

2008 ◽  
Vol 48 (2) ◽  
pp. 156 ◽  
Author(s):  
K. B. Kelly ◽  
F. A. Phillips ◽  
R. Baigent
Keyword(s):  
Nitrous Oxide ◽  
New Zealand ◽  
Dairy Cow ◽  
Production Systems ◽  
Animal Production ◽  
Soil Conditions ◽  
N2o Emissions ◽  
Cow Urine ◽  
Reduce Emissions ◽  
Animal Production Systems

Animal production systems in Australia are a significant contributor to nitrous oxide (N2O) emissions from soil, with the Australian Greenhouse Gas Inventory attributing ~25% of the N2O emissions from agricultural soils to animal production. Recent studies in New Zealand using dicyandiamide (DCD) in association with the application of urine to pastoral soil have reported reductions in N2O emission of up to 78% and reduced nitrate leaching of up to 45%. As such, the application of DCD to grazed pastures offers potential to reduce emissions resulting directly from animal production. This study was conducted on a border-check irrigated perennial pasture used for dairy production in northern Victoria. Automated enclosure chambers were linked to a fourier transformed infrared spectrometer to determine N2O emissions. The three treatments were a control, dairy cow urine (1000 kg N/ha) and dairy cow urine (1000 kg N/ha) with DCD included (10 kg/ha). The treatments were applied in mid-spring (15 September 2005) and again in mid-summer (25 January 2006) to a new area of pasture with N2O emissions measured for 120 and 70 days, respectively. Soil temperature and soil water content were monitored continuously. Soil inorganic-N was measured (0–100 mm) every 7 to 14 days for up to 120 days. Application of DCD reduced N2O emissions from a urine patch by 47% when applied in mid-spring and 27% when applied in mid-summer. The impact of the application of DCD on emissions from single urine patches lasted for ~50 days in mid-spring and 25 days in mid-summer. These reductions are lower than those reported in New Zealand studies and are likely to be related to soil conditions, principally temperature. The surface application of DCD has potential to reduce emissions from urine patches in northern Victoria; however, the effects are likely to be short-lived given the soil temperatures and high clay content typical of many Australian soils. More research is required to examine emission reduction options that are cost effective for animal production systems.

White clover: the forgotten component of high-producing pastures?

2017 ◽  
Vol 57 (7) ◽  
pp. 1269 ◽  
Author(s):  
D. F. Chapman ◽  
J. M. Lee ◽  
L. Rossi ◽  
G. R. Edwards ◽  
J. B. Pinxterhuis ◽  
...  
Keyword(s):  
New Zealand ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Production Systems ◽  
Nutrient Loss ◽  
Dairy Production ◽  
Lolium Perenne L ◽  
Agronomic Practices ◽  
Trifolium Repens L ◽  
N Rates

The contribution of white clover (Trifolium repens L.) to nitrogen fixation and feed quality in mixed pastures is indisputable, but the benefits of clover inclusion to total herbage accumulation (HA) are less clear. Results from four experiments comparing mixed pastures of white clover–perennial ryegrass (Lolium perenne L.) with perennial ryegrass monocultures are presented. These experiments covered a range of environments (dryland northern New Zealand and irrigated southern New Zealand), management inputs (nitrogen (N) fertiliser rates and defoliation management), and genotypes of ryegrass and white clover. Mixtures resulted in a significantly greater HA than did monocultures in 7 of the 8 years for which data were available; the interaction between pasture type (monoculture or mixture) and N rate was significant in six of those years, with a greater advantage in HA for mixtures under low N rates (mean = 3.08 t DM/ha.year) than under high N rates (mean = 1.54 t DM/ha.year). Two-thirds to four-fifths of the yield advantage under grazing was due to the direct effect of clover contribution (which ranged between 10% and 30% of total annual yield) to HA, most of which accrued in summer. The remainder was due to the capture of additional clover-derived N by the grass component of the mixture, estimated to equate to 50–60 kg N/ha under low N-fertiliser rates and 15–35 kg N/ha under high N rates. The magnitude and consistency of the yield advantages observed here indicates that there are unrealised yield and other benefits not currently being captured in New Zealand dairy production systems, largely because they are negated by the use of high N-fertiliser rates. The agronomic practices required to support clover-rich mixed pastures receiving moderate rates of N fertiliser are well documented and can be applied to help deal with nutrient loss limits required by environmental regulations plus volatility in farm-gate milk prices.

scholarly journals ASPECTS OF THE FEEDING AND NUTRITIVE VALUE OF LOTUS SPECIES

1981 ◽  
pp. 152-159 ◽  
Author(s):  
A. John ◽  
J.A. Lancashire
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Condensed Tannins ◽  
Nutritive Value ◽  
Red Clover ◽  
Protein Digestion ◽  
Weight Gains ◽  
Feeding Value ◽  
Feeding Trials

Daily weight gains of sheep in pure sward grazing trials showed relative feeding values to be in the order: white clover (100) > sainfoin (97), Maku lotus (87) > lucerne, red clover (78) > perennial ryegrass (52). The high feeding value of lotus and sainfoin may be due to the presence of condensed tannins which have been shown to improve protein digestion and utilization in indoor feeding trials.

Combining seasonal yield, silage dry matter yield, quality and persistency in an economic index to assist perennial ryegrass variety selection

2016 ◽  
Vol 155 (4) ◽  
pp. 556-568 ◽  
Author(s):  
M. O'DONOVAN ◽  
N. MCHUGH ◽  
M. MCEVOY ◽  
D. GROGAN ◽  
L. SHALLOO
Keyword(s):  
Perennial Ryegrass ◽  
Dry Matter ◽  
Production Systems ◽  
Decision Making Process ◽  
Economic Potential ◽  
Yield Data ◽  
Economic Values ◽  
Variety Selection ◽  
Yield Quality ◽  
Yield Threshold

SUMMARYA total economic merit index (Pasture Profit Index, PPI) for perennial ryegrass variety selection was developed to rank perennial ryegrass varieties (Lolium perenneL.) based on their economic potential for grass-based ruminant production systems. The key traits of importance identified were: spring, mid-season (April 11–August 10) and autumn dry matter (DM) yield, first and second cut silage DM yield, grass quality April to July (inclusive) and sward persistency. Variety persistency was quantified by determining the ground score (GS) change across years, which was associated with a yield threshold which triggered sward replacement. Each one-unit decline in GS was associated with a 1683 kg loss in DM yield. Data generated in the Irish recommended list trials for value for cultivation and use were analysed to quantify the relative performance of each variety for each of the aforementioned traits. A previously developed methodology to generate economic values was used with updated price assumptions to develop economic values, which were applied to the analysed performance data of individual varieties. These data were used to estimate the total economic merit of each variety. Thirty-nine varieties were ranked on total economic merit with the highest performing variety (Cv111) generating €213 per ha/year compared withCv201, which was the lowest ranking variety generating −€31 per ha/year. Use of the PPI provides information to end users in relation to the economic merit of one variety over another, facilitating a more informed decision-making process at farm level.

scholarly journals THE NUTRITIVE VALUE OF LEGUMES

1976 ◽  
pp. 107-118 ◽  
Author(s):  
M.J. Ulyatt ◽  
J.A. Lancashire ◽  
W.T. Jones
Keyword(s):  
Perennial Ryegrass ◽  
Nutritive Value ◽  
Feeding Experiments ◽  
Protein Energy ◽  
Feeding Value

Evidence is reviewed to show that, in most circumstances, legumes are of higher nutritive value than grasses. The reasons for such differences are explored using evidence from indoor feeding experiments. In particular, the superiority of legumes over perennial ryegrass appears to be due to a higher intake and a higher ratio of protein/energy absorbed. The mechanisms by which tannins in legumes such as Lotus and sainfoin can reduce bloat and improve nutritive value are also considered. Finally, the management of legumes in relation to their higher feeding value is discussed. It was considered that, because of agronomic factors, the superior nutritive value of legumes is not being exploited in agriculture.

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