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This experiment aimed to characterise the concentration of secondary compounds aucubin, catalpol and acteoside in plantain (Plantago lanceolata) herbage and determine if harvesting at different times or nitrogen (N) fertiliser inputs alter concentrations. Herbage of plantain was harvested each season over two years from plots fertilised at 180 or 450 kg N/ha/yr. At each harvest date, samples were taken in at 0700 h and 1600 h. The concentration of secondary compounds in plantain herbage was greatest for acteoside (range 1.77-36.0 mg/g DM), intermediate for aucubin (range 0.566-5.85 mg/g DM) and lowest for catalpol (<0.390 mg/g DM). Compound concentrations were unaffected by N fertiliser and showed limited diurnal fluctuation. There was a strong seasonal effect on all secondary compounds with peaks in concentration occurring in spring for aucubin and acteoside. This experiment suggests environmental factors other than soil N fertility and diurnal patterns influence the concentration of secondary compounds in plantain. [ABSTRACT FROM AUTHOR]

Irrigated, diverse pastures were managed under normal (grazed to 3.5 cm) or lax (grazed to 5 cm allowing ryegrass seed head development) grazing intensity, with or without mowing (to 3.5 cm), in spring. On the subsequent grazing rotation in summer, an experiment was conducted to investigate the carry-over effects of previous management on herbage regrowth and milk production. Nine groups of three Friesian × Jersey dairy cows each were randomly allocated to three replicates of three treatments: normal grazing (Norm); previously lax managed pastures (Lax); previously lax managed pastures that were pre-graze mown (Mow). Herbage in Mow treatments had a higher ME (p < 0.05) than Lax and Norm (11.7, 11.3 and 11.4 MJ ME/kg DM, respectively). There was no difference in dry matter intake (18 ± 0.30 kg DM/cow/d) or MS production (1.85 ± 0.02 kg MS/cow/d) among treatments. Results of this study indicated that milk production was not altered by grazing management. [ABSTRACT FROM AUTHOR]

The effects of 50% or 100% of a herbage diet of plantain on milk production and urinary nitrogen (N) concentration were measured in two experiments for late (autumn 2015) and early (spring 2015) lactation dairy cows. Three groups of 12 mixed age Friesian × Jersey dairy cows were offered a perennial ryegrass-white clover pasture, or pure plantain or 50% perennial ryegrass-white clover and 50% pure plantain by ground area (50–50 pasture–plantain). Urine N concentration was lower in both experiments (P< .001) for plantain (2.4 and 2.2 g N/L) and 50–50 pasture–plantain (3.6 and 3.4 g N/L) than pasture (5.4 and 4.7 g N/L). Cows on plantain or 50–50 pasture-plantain produced at least as much milk as those on pasture in both experiments. Plantain may offer environmental benefits to dairy systems by reducing the N concentration of urine deposited on the soil from grazing cows. [ABSTRACT FROM PUBLISHER]

Emissions of nitrous oxide from grassland systems are attributable largely to the use of nitrogen fertilisers and the excreta deposited by grazing animals. There is increasing interest in using gibberellins as a naturally-occurring growth promotant of herbage that could be used to reduce the use of nitrogen fertilisers while leading to similar or greater increases in dry matter. This may provide practical opportunities to reduce nitrogen intake by ruminants and extend the seasonality of herbage growth in spring and autumn while reducing nitrogen losses, resulting in lower rates of nitrogen excretion by grazing animals and reduced nitrous oxide emissions. Our findings from a review of previous studies confirm that gibberellins promote dry matter production, especially when applied in early spring or late summer/early autumn. When gibberellins are applied alone without nitrogen fertiliser, the nitrogen concentration of herbage is reduced and the impacts on forage quality are small and often not significantly different from those for untreated controls. We calculated the consequences of enhanced herbage production on nitrogen excreta returned to the soil as urine by a grazing dairy cow and estimated that one application of gibberellins will result in a relative reduction in nitrous oxide emission per urination event of 18% when compared with emissions from using nitrogen fertiliser. We used the OVERSEER ® model and nitrous oxide emissions factors to estimate the impacts of changing herbage dry matter production, foliage nitrogen concentration and timing of one application of gibberellins on annual nitrous oxide emissions for a dairy farm. For one application of gibberellins in late summer and early spring, we estimate reductions in nitrous oxide emissions of 1.6% and 1.3%, respectively, relative to the response for an untreated control. Incorporating the effects of reduced use of nitrogen fertiliser by substituting one split application of fertiliser in late summer or autumn with gibberellins, we estimate reductions on nitrous oxide emissions of between 5 and 6% relative to the response for the untreated control. We conclude that the use of gibberellins with reduced addition of nitrogen fertiliser has the potential to reduce nitrous emissions from grazed grassland. However, acceptance of widespread use of gibberellins will be dependent on cost benefit analysis for farmers. [ABSTRACT FROM AUTHOR]

Recent research in Europe has suggested that stem mining insects may be important for vectoring the pathogen Puccinia punctiformis, and largely responsible for its systemic infection in the weed, Cirsium arvense. However, here we present comparative survey data showing that the level of systemic disease is the same in Europe and New Zealand, with and without stem miners, respectively, casting doubt on the idea that these insects are necessary for transmission of the fungus. [ABSTRACT FROM AUTHOR]

Context: Plantain has shown promise as a forage that can mitigate nitrogen (N) losses from farm systems, although adoption and regulation requires knowledge of the minimum amount of forage area or diet quantity to observe an effect. Aims: A grazing study was conducted to evaluate the effect of offering increasing proportions of spatially adjacent plantain (PL) and perennial ryegrass–white clover (PRGWC) on milk production and N utilisation of dairy cows. Methods: Forty-eight late lactating cows blocked into replicated (n = 3) groups of four cows were randomly allocated to one of the following four forage treatments based on percentage area of plantain: 0%, 15%, 30%, or 60%. Cows were allocated 25 kg DM/cow.day of forage above ground level daily on the basis of metabolisable energy requirements. Dry matter intake was estimated from the difference between pre- and post-grazing pasture mass, using a calibrated electronic rising-plate meter. Milk production was measured as yield and milk solids, while N use was estimated from total milk N excretion and spot subsamples of blood, urine and faeces. Key results: Offering cows spatially adjacent strips of PL increased apparent dry matter intake compared with PRGWC pasture alone (16.4 vs 15.1 kg DM/cow.day, P = 0.027) and apparent metabolisable energy intake (203 vs 188 MJ/kg.cow.day, P < 0.001). Milk yield (16.1 kg/cow.day), milk solids production (1.6 kg/cow.day) and fat concentration (5.69%) were unaffected by the proportion of plantain in the diet. PL offered at 60% of the area increased milk protein concentration compared with PRGWC (4.65 vs 4.36%, P < 0.01). There was no treatment effect on total apparent N intake (563 g N/cow.day), N excretion in milk (113 g N/cow.day) and N-utilisation efficiency (20 g milk N/100 g N consumed). However, total milk urea, blood urea and urine urea N concentrations declined with increasing plantain in the diet, reflecting an influence on urea metabolism. Conclusions: Offering plantain to grazing dairy cows did not improve milk yield or N-use efficiency, but influenced urea metabolism. Implications: Sowing plantain in spatially separate strips within perennial ryegrass–white clover pastures is a useful option to achieve target levels of plantain in the diet and, in conjunction with other mitigation strategies, can be used to improve the sustainability of pastoral dairy farming. Pastures that reduce the dairy nitrogen impact on the environment and increase milk production are desirable. Plantain is such pasture; however, limited knowledge on its inclusion rates in diets to make such a difference has not been generated. Including 15–60% plantain in dairy pastures reduced nitrogen in urine and maintained milk production similarly to ryegrass white clover. The implications of these results indicate that dairy farms may maintain milk production and emit less harmful nitrogen into water sources. [ABSTRACT FROM AUTHOR]

Future development pathways for irrigated dairy farms in Canterbury operating under stricter nitrogen (N) loss limits were compared in two farmlets over four years. One represented the traditional pathway of intensification via higher inputs of N fertiliser and supplementary feed ('higher input-high efficiency', HI-HE), while the other represented a lower input pathway using half the amount of N fertiliser and one quarter the amount of supplementary feed ('lower input-high efficiency', LI-HE). The stocking rate of both systems was matched to feed supply to achieve high utilisation (∼90%) of the pasture grown. Mean total annual N surplus and estimated nitrate-N leaching were lower in LI-HE than HI-HE, by 46% and 25% respectively. Milk production was lower for LI-HE (1,700 kg versus 2,240 kg milk fat + protein per ha/year). Estimated profit was the same for both systems at a milk price of $6.46/kg fat + protein, below which LI-HE was more profitable than HI-HE and vice-versa. Compared with the benchmark high-performing Lincoln University Demonstration Dairy Farm (LUDF) through the same period, LI-HE was 2% less profitable, but estimated N leaching was ∼30% lower. Subsequent adoption of the LI-HE system by LUDF demonstrated that the system is scalable, and profitable. [ABSTRACT FROM AUTHOR]

Eight perennial ryegrass cultivars (representing the variations in ploidy, heading date and water‐soluble carbohydrates concentration) were investigated for morphology and nutritive value at three phenological stages: pre‐heading vegetative, reproductive and post‐flowering vegetative stages. Chemical compositions and digestibility of morphological components (lamina, pseudostem and reproductive stem) from each perennial ryegrass cultivar were analysed in a split‐plot design. At the vegetative stages, perennial ryegrass cultivars differed significantly in the proportions of lamina and pseudostem. Tetraploid cultivars, Base and Bealey, always had the greatest lamina proportion (51.8% and 53.2% at the pre‐heading and post‐flowering vegetative stages respectively). At the reproductive stage, the emergence of seed heads diminished the differences in morphology among cultivars. Perennial ryegrass cultivars also had distinct nutritive value throughout three phenological stages. The high‐sugar cultivar, AberMagic, had high WSC concentrations (276, 227 and 90 g/kg DM at the pre‐heading vegetative, reproductive and post‐flowering vegetative stages respectively); the intermediate‐heading cultivars, Kamo and Commando, generally had a lower organic matter digestibility in dry matter than the late‐heading cultivars at the pre‐heading vegetative (70.7% vs. 74.4%) and reproductive stage (63.9% vs. 68.2%). However, although the morphological components were different in nutritive value consistently, the differences in morphology did not account for the variation in nutritive value among perennial ryegrass cultivars. [ABSTRACT FROM AUTHOR]

An outdoor grazing study conducted with 45 non-lactating, pregnant dairy cows during winter measured dry matter (DM) intake, grazing behaviour, rumen pH, ammonia (NH3) and volatile fatty acids (VFAs) of cows fed 11 (K11) or 14 (K14) kg of kale DM/cow/day or 11 (G11) kg DM Italian ryegrass/cow/day. Cows in K14 spent more time grazing (441 min/day) than in K11 (9378 min/day) and G11 (326 min/day). Rumen ammonia concentrations ranged from 108 to 212 mg NH3/L for K14, 91 to 306 mg NH3/L for K11 and 57 to 269 mg NH3/L for G11. Total VFAs concentration (mmol/L) was greatest for K14 (104), intermediate at G11 (96.7) and lowest for K11 (75.4). Rumen pH fell to reach its lowest values of 5.7 for G11, 6.2 for K11 and 6.1 for K14. Hence, there was little evidence of sub-acute rumen acidosis in kale-fed cows. [ABSTRACT FROM AUTHOR]

Pasture mitigation strategies are needed to reduce the negative effects of nitrate (NO3−) leaching from intensive pastoral livestock production systems. We explored the capability of pasture grasses with different cool season (winter-early spring) growth rates to reduce NO3− leaching and increase N uptake. Following a single urine application of 700 kg N ha−1, NO3− leaching loss and N uptake by Italian ryegrass and four perennial ryegrass cultivars of varying seasonal growth (heading dates from -7 to +20 days), either undersown with/without Italian ryegrass, were quantified in a 12 month lysimeter study. Italian ryegrass cv. Tabu had lower NO3−-N leaching loss and drainage, and greater N uptake and DM yield than perennial ryegrass varieties. Italian ryegrass total N leaching loss (143 kg N ha−1 yr−1) was 46-33% less (P < .05) than early and mid-season maturing Tyson, Arrow and AberDart perennial ryegrass. Italian ryegrass total N uptake (463 kg N ha−1) was 1.2-1.4 times greater than all other grass sward types. Overall, perennial ryegrass pure swards had similar N uptake and N leaching. Late-season maturing One 50 perennial ryegrass showed significantly reduced (P < .05) total N leaching loss. Undersowing Italian ryegrass into established perennial ryegrass swards resulted in lower NO3− leaching and greater N uptake than non-undersown perennial ryegrass swards, though not significant. Results confirm Italian ryegrass is a useful pasture grass option for reducing annual N leaching loss. Cool season perennial ryegrass varieties appear not to influence soil N uptake and leaching loss. [ABSTRACT FROM AUTHOR]

In grazed agricultural systems, animal urine patches are the major source of nitrogen (N) leaching losses and can cause a decline in water quality. Urine‐N rates often exceed plant requirements, and there is a need for mitigation options to reduce the impact of agriculture on the environment. One approach is to use alternative forages to reduce urine‐N loading rates, or to increase N uptake. This study used lysimeters to determine the N leaching losses, dry matter yields and N uptake following ruminant urine application to an Italian ryegrass‐plantain‐white clover forage mix (IRPWC, Lolium multiflorum Lam.‐Plantago lanceolata L.‐Trifolium repens L.) or perennial ryegrass‐white clover (PRWC, Lolium perenne L.‐T. repens L.). Three urine treatments were applied: Control (no urine), Urine Actual (urine from cows grazing each of the forages: 508, and 664 kg N/ha, for IRPWC and PRWC, respectively) and Urine 700 (700 kg N/ha). Compared with PRWC (113 kg N/ha), N leaching losses were 88.9% lower from IRPWC‐Urine Actual (12.5 kg N/ha) and 45.5% lower from IRPWC‐Urine 700 (61.8 kg N/ha). These reductions were attributed partly to the IRPWC having higher cool season activity and ability to take up N during the cool period, and partly to the lower concentration of urine‐N, compared with PRWC. IRPWC is a promising alternative forage for future farm systems with the ability to reduce urine‐N excretion from grazing animals and cause large reductions in N leaching losses while producing the same herbage dry matter yields as PRWC. [ABSTRACT FROM AUTHOR]

The effect of two irrigation rates on nitrogen (N) harvested by diverse and standard forages, and the subsequent effect on nitrate (NO3−) leaching losses from spring deposited urine was investigated. An experiment, using lysimeters (500 mm diameter, 700 mm deep), was conducted to measure herbage dry matter yield, herbage N harvested and NO3- leaching loss beneath a ‘standard forage’ and a ‘diverse forage’. Cow urine was applied to the forages at either 500 or 700 kg N ha-1, and following the urine application, irrigation was applied at a rate of 18 mm approximately every 3 days (high) or 9 mm approximately every 3 days (low) from November to April. Compared with low irrigation, NO3- leaching losses were 88-97% lower under high irrigation at a urine application rate of 700 kg N ha-1, and were less than 4 kg N ha-1 from all high irrigation treatments. [ABSTRACT FROM AUTHOR]

For Australian and New Zealand dairy farms, the primary source of home-grown feed comes from grazed perennial pastures. The high utilisation of perennial pasture is a key factor in the low cost of production of Australian and New Zealand dairy systems and, hence, in their ability to maintain international competiveness. The major pasture species used are perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), normally grown in a simple binary mixture. As pasture production has been further driven by increasing use of nitrogen fertiliser and irrigation, farms are getting closer to their economic optimum level of pasture utilisation. Increasing inputs and intensification have also increased scrutiny on the environmental footprint of dairy production. Increasing the diversity of pasture species within dairy swards presents opportunities to further increase pasture utilisation through additional forage production, extending the growing season, improving forage nutritive characteristics and, ultimately, increasing milk production per cow and/or per hectare. Diverse pastures also present an opportunity to mitigate some of the environmental consequences associated with intensive pasture-based dairy systems. A consistent finding of experiments investigating diverse pastures is that their benefits are due to the attributes of the additional species, rather than increasing the number of species per se. Therefore, the species that are best suited for inclusion into dairy pastures will be situation specific. Furthermore, the presence of additional species will generally require modification to the management of dairy pastures, particularly around nitrogen fertiliser and grazing, to ensure that the additional species remain productive and persistent. Diverse pastures offer benefits to pasture-based dairy systems in terms of increased forage and animal production, improved resilience and the potential to reduce nitrate leaching. The management required to maintain the diversity in the pastures may limit their application. However, the benefits of diverse pastures can be archived with only three species making their management and application simpler. [ABSTRACT FROM AUTHOR]

This study aimed to identify suitable predictors of nitrogen (N) use efficiency (NUE; milk N/N intake) for cows that differed in breeds and were fed with ryegrass pasture, using existing data from the scientific literature. Data from 16 studies were used to develop models based on the relationships between NUE and dietary and animal-based factors. Data from a further 10 studies were used for model validation. Milk urea N (MUN) and dietary water-soluble carbohydrate-tocrudeprotein ratio (WSC/CP) were the best and most practical animal- and diet-based proxies to predict NUE. The results indicate that it might be necessary to adopt separate models for different breeds when using WSC/CP to predict NUE but not when using MUN. [ABSTRACT FROM AUTHOR]

An amino acid substitution (K232A) in the enzyme diacylglycerol acyl-CoA acyltransferase 1 (DGAT1) has been reported to explain variation in milk traits and milk fatty acid (FA) profile. In this study, associations between K232A, and milk traits including milk FA composition, were studied in wholly pasture-fed New Zealand Holstein-Friesian × Jersey cross-bred (KiwicrossTM) dairy cows. With a high frequency of K variant (61.9%), the KK cows produced more milk fat on average (5.41 ± 0.04%), than the AA cows (4.43 ± 0.06%). The milk volume, fat concentration and protein concentration for the AK cows were between the values for the genotypes AA and KK. More C16 : 0 (saturated fatty acid), conjugated linoleic acid (CLA) and polyunsaturated fatty acid (C18:3 cis-9, 12, 15) were found in the milk of the KiwicrossTM cows, and the influence of DGAT1 K232A on these FAs during the mid- and late- stage of lactation were significant. The AA cows produced more (P < 0.001) CLA (1.137 ± 0.047 g/100 g) and C18:3 cis-9, 12, 15 (0.855 ± 0.015 g/100 g), but less C16:0 (35.170 ± 0.355 g/100 g) than the KK cows (0.934 ± 0.025 g/100 g, 0.778 ± 0.009 g/100 g and 38.010 ± 0.250 g/100 g respectively). [ABSTRACT FROM AUTHOR]

The study investigated the effect of stage of lactation and Breeding Worth (BW) index on estimated dry matter intake (DMI), milk solids (MS) production, energy use efficiency (EUE) and feed conversion efficiency (FCE) of grazing cows. Two hundred crossbred cows with similar calving date (14 August ± 9.97 days), live weight (471.5 ± 44.02) and age (7.5 ± 1.25 years) were separated into five groups (n = 40) based on New Zealand BW index: Low BW (BW = 63.1); Medium Low BW (BW = 88.2); Medium BW (BW = 19.1); Medium High BW (BW = 128.9); and High BW (BW = 146.9). Milk samples were collected in early, mid and late lactation and herbage samples were taken the day before milk sampling. The DMI was estimated by back-calculation based on metabolizable energy requirement for maintenance and production. The MS production, herbage DMI, EUE and FCE declined from early to late lactation. The overall results suggest regardless of the stage of lactation, cows with higher BW had a higher DMI, MS production and FCE. [ABSTRACT FROM AUTHOR]

Breeding cows for improved production and production efficiency may have led to indirect selection for behavioural traits including grazing and urination behavioural patterns. This study investigated the relationship between genetic merit (breeding worth; BW) and grazing and urination behaviour in Holstein-Friesian × Jersey lactating dairy cows. Two groups of 12 cows were assigned into high BW (HBW; NZ$146 ± 12.8) or low BW (LBW; NZ$40 ± 11.8) groups. Cows were observed for grazing (grazing, ruminating, idling and bite rate) and urinating (frequency and duration of urination events) behaviour during the first grazing session of the day (5 h; between milking 0900–1400 h). Based on the whole grazing and urination behaviour data matrix, MANOVA and PCA procedures suggested no difference in the grazing and urination behaviour of HBW and LBW cows. Further work measuring additional traits (e.g. intake rate, bite mass, diurnal urination patterns) may be required to differentiate cows of divergent BW based on behavioural patterns. [ABSTRACT FROM AUTHOR]

Four levels of plantain (0%, 25%, 50% and 75% on DM basis) inclusion rate to ryegrass-clover pasture and three target heifer mature live weights, 444 kg (representing Jersey), 529 kg (Friesian), and 492 kg (cross bred Jersey × Friesian) were tested in this modelling exercise for a 30 ha farm and 24-month analysis. The annual average growth rates were 30 kg DM/ha/day and 23 kg DM/ha/day for plantain and perennial ryegrass-white clover, respectively. Feeding plantain increased animal live weight gain, but on a whole farm level, total live weight gain was similar between the three target weight treatments. Stocking rate was identified as a major driver of nitrogen leaching in this study, which resulted in a decreased nitrogen leaching with increased target live weight groups. Increased annual nitrogen leaching value was found from feeding plantain to animals, which contrasts to previous speculation from animal studies. [ABSTRACT FROM AUTHOR]

Livestock urine deposition onto grazed New Zealand pastures drives soil nitrous oxide (N2O) emissions. Urine patch N2O emissions can be reduced by inhibiting nitrification, a key urine patch nitrogen (N) transformation pathway. Aucubin, a secondary metabolite found in the pasture herb species plantain (Plantago lanceolata), is a potential nitrification inhibitor and could be excreted in urine by animals grazing plantain. In this laboratory trial, three rates of aucubin application (10, 50, and 100% of the highest theoretical aucubin excretion rate from cows grazing 100% plantain pasture) were added to urine and assessed for their potential to inhibit nitrification and subsequent N2O emissions. Significantly reduced N2O flux and soil N O 3 − concentrations, aligned with significantly increased soil N H 4 + and soil surface pH, indicated that aucubin inhibited nitrification from 5 to 17 days after urine application. However, this period of inhibition was not sufficient to reduce overall N2O emissions during the 35 day experiment. [ABSTRACT FROM AUTHOR]

Ruminant urine patches are nitrous oxide (N2O) emission hot-spots and compounds that inhibit nitrification in urine-affected soils, a key step in soil N2O production, can significantly reduce N2O emissions. Aucubin, a potential nitrification inhibitor found in plantain (Plantago lanceolata) was assessed in two field trials for its efficacy in reducing urine patch nitrate (NO3−) accumulation and N2O emissions. Plantain leaf extract or commercially derived pure aucubin was added to urine, alongside a control and urine only treatment, and applied to standard gas chambers and monitored for 35 days. While there were some daily differences between treatment soil nitrogen and N2O emissions, there were no overall significant differences between cumulative N2O emissions. Aucubin, applied as a one-off dose, seems to act as a nitrification inhibitor for a short period after application onto soil, but it's inhibitory effects are not sufficient to produce significant reductions in overall urine patch N2O emissions. [ABSTRACT FROM AUTHOR]

The objective of this study was to model the growth of dairy heifers to estimate the effects of breed and heterosis on live weight (LWT) and growth from three to 22 months of age. Data comprised of 1,653,214 LWT records obtained from 189,936 dairy heifers in 1547 herds. At all ages Holstein-Friesian (F) heifers were heavier than Holstein-Friesian-Jersey crossbred (F × J) which were heavier than Jersey (J) heifers. Heterosis effects for LWT were greatest at nine months of age (3.6%) and least at 22 months of age (2.0%). The growth pattern differed, as evidenced by the regression coefficients of the Legendre polynomial. Growth was non-linear and heterosis effects were different throughout the growth period. Friesian, J and F × J heifers exhibited different growth patterns. These differences in growth pattern should be considered when formulating target LWTs and growth rates for a pasture-based system. [ABSTRACT FROM AUTHOR]

The aim of this research was to assess the potential of using perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) forages containing plantain (Plantago lanceolata L.) (PRGWC + Plantain) to mitigate nitrate (NO3−) leaching in grazed grassland. Lysimeter studies were carried out to determine NO3− leaching losses from the PRGWC + Plantain forage, compared with the standard perennial ryegrass and white clover forage (PRGWC) under three different irrigation conditions (flood, rotorainer and pivot). Fresh dairy cow urine (700 kg N ha−1) was applied to these lysimeters in early summer (December) and late summer (February). Nitrogen (N) dynamics and the abundance of ammonia oxidising bacteria (AOB) and archaea (AOA) were also determined in companion mini-plots alongside the lysimeters. Nitrate leaching losses from the PRGWC + Plantain forage were 82% lower than those from the PRGWC forage when urine was applied in December and 74% less when urine was applied in February (P < .05). This was possibly due to the release of biological nitrification inhibitors by plantain which slowed down the nitrification process and this, combined with a lower drainage volume, was largely responsible for the lower NO3− leaching losses in the PRGWC + Plantain forages. The three different irrigation schemes did not significantly affect NO3− leaching losses under the two forage types. These results demonstrate the potential of using PRGWC + Plantain forages as an effective mitigation option for NO3− leaching in grazed grasslands. [ABSTRACT FROM AUTHOR]

Highlights • Cows on a round-stone stand-off pad achieve acceptable time of lying down per day. • Frequency of lying is lower than normal when cows are on stone surface. • Sand surface in an uncovered stand-off system results in dirty cows. • Woodchip and carpet surfaces equally meet animal welfare standards. • Woodchip surface requires less maintenance than carpet. Abstract The objective of this study was to investigate the effect of stand-off surface type on cow lying behaviour, cleanliness and lameness. One hundred and sixty Friesian × Jersey crossbreed, pregnant non-lactating dairy cows were blocked into five groups of 32 cows and randomly assigned to one of five treatments. Treatments consisted of cows grazing fodder beet in situ and remaining in the paddock with no stand-off (control), or grazing fodder beet in situ and spending 16 h on a stand-off pad with either a woodchip, round-stones (40–60 mm), sand, or geotextile 'carpet' surface. Lying duration, monitored by AfiAct electronic pedometers (Afimilk, Kibbutz Afikim, Israel), showed cows on stone spent significantly more (P < 0.001) time lying (9.5 h) than cows on woodchip (8.4 h), control (8.1 h), and sand (7.6 h), but similar to those on carpet (8.8 h). However, there were fewer (P < 0.001) lying bouts (4.6 bouts/d) and longer (P < 0.001) bout duration (137 min/bout) for cows on stone than other treatments (average 7 bouts/day and 85 min/bout), which may suggest that cows found standing and sitting on the stone surface uncomfortable. As measured by a cleanliness score, cows on the sand surface were less (P < 0.001) clean than cows on other surfaces. Lameness, which was determined by visual scoring, revealed only moderate cases of lameness which tended (P = 0.059) to be more prevalent for cows on stone (11.3%) or sand (12.5%), compared with lowest in woodchip (4.0%) or carpet (4.7%), and intermediate in the control treatment (8.8%). The data indicate that sand and the size of stone used are less suitable surfaces than woodchip or carpet for an uncovered winter stand-off pad to meet minimum requirements of animal comfort and welfare. While both the woodchip and carpet surfaces equally met animal welfare standards, the woodchip required less maintenance. [ABSTRACT FROM AUTHOR]

This study investigated the effects of three forage treatments [herbal plantain (PL), ryegrass-white clover pasture (RW) and root crop fodder beet (FB)] on ex-vivo rumen fluid fermentations. Quantitative real-time Polymerase Chain Reaction (qPCR) and PCR-single-stranded conformation polymorphism (PCR-SSCP) analyses were undertaken for aliquots collected from the fermentations. The FB treatment had the highest volatile fatty acid (VFA) and lowest pH compared with other treatments. The RW culture that had a higher fibre content, had higher Fibrobacter succinogenes(F. succinogenes) and anaerobic fungi levels when compared with the FB and PL. Protozoans were however the most abundant microorganisms in the FB cultures, and they had the highest water-soluble carbohydrate (WSC) content. The abundance of F. succinogenes increased in the RW fermentation up to 12 h, and the abundance of anaerobic fungi increased in the RW fermentation up to 24 h. In all the treatments, no effect was found on the overall abundance of bacteria. The findings confirmed that changes in rumen microbial community and fermentation products are partly related to the WSC and fibre content of two novel forages (i.e. PL and FB) increasingly used in animal production. [ABSTRACT FROM AUTHOR]

An outdoor grazing study on kale was conducted with pregnant, nonlactating (dry) dairy cows over a 42‐day winter grazing period commencing 9 June 2008. Kale treatments consisted of two kale cultivars varying in leaf:stem proportion ("Regal," a leafy variety and "Caledonian," a stemmy variety) and two sowing dates (8 November and 15 December). Measurements were made for dry‐matter (DM) utilization, apparent DM intake, liveweight gain and changes in body condition score (BCS) for a total of 120 cows allocated to three replicate groups of the four factorial treatments. Cows were offered a daily allowance of 10 kg DM/cow of kale and 2.2 kg DM/cow of straw. Pregrazing DM yield was higher for kale sown in November (16,517 kg DM/ha) than December (13,867 kg DM/ha), but was unaffected by cultivar (average 15,192 kg DM/ha). "Regal" kale had a higher percentage of leaf compared with "Caledonian" (33.6% vs. 25.6%), lower content of NDF (32.4% vs. 34.1%), but similar metabolizable energy content (12.1 MJ/kg DM for both) in the whole plant. Despite the differences in pregrazing DM yield and forage quality among treatments, no differences were found in DM utilization (between 88.5% and 90.2%), apparent DM intake (between 9.4 and 9.6 kg DM/cow.day), liveweight gain (between 0.53 and 0.67 kg/cow.day) and BCS gain (between 0.43 and 0.46 unit/cow over 42 days). Manipulation of kale yield and quality through choice of cultivar and sowing date had no effect on the performance of pregnant, nonlactating dairy cows. [ABSTRACT FROM AUTHOR]

Plantain (Plantago lanceolata L.), a forage used in grazed pastures, contains active secondary metabolites that could potentially inhibit nitrification, a key step in nitrous oxide (N2O) production from grazing ruminant livestock urine patches. A field study was performed to determine the effects of aucubin, a secondary metabolite in plantain, on nitrification and soil N2O emissions under a ruminant urine patch. Soils were treated with bovine urine (700 kg ha−1) and either a plantain leaf extract (PLE), which contained all extractable compounds in plantain including aucubin, or an aucubin solution (AS). PLE and AS were applied at the same rate of aucubin (47 kg ha−1). N2O emissions were reduced by 50% and 70% in the PLE and AS treatments, respectively; however, there were no significant differences in soil inorganic nitrogen concentrations when urine was applied with PLE or AS. [ABSTRACT FROM AUTHOR]

Herbage accumulation (HA) data from four sites were combined to (1) address the hypothesis that adjustments to the New Zealand Forage Value Index to account for grass-clover interactions are not required and (2) explore the main effects of clover and nitrogen (N) fertiliser treatments on pasture productivity. In summer and autumn, pastures based on mid-season heading ryegrass cultivars consistently supported a greater clover content than pastures based on late heading cultivars. However, the clover ×  cultivar interaction was significant in only 2 of 17 HA data sets available for analysis. Thus, the hypothesis is supported. Compared with ryegrass monocultures, mixtures yielded an additional 2.4 (in the Low-N treatment) and 1.2 (High-N treatment) t DM/ha/year. Apparent N transfer from clover to grass was 79 (Low N) and 27 (High N) kg N/ha/year, derived from estimated N fixation efficiencies of 66 (Low N) and 50 (High N) kg N/t clover DM grown. [ABSTRACT FROM AUTHOR]

This paper describes how the core treatments in the national experimental design (all combinations of with/without clover and high/low nitrogen (N)) were implemented at an irrigated Canterbury site and monitored for three years. There was a consistent N × clover interaction, caused mainly by substantially lower yields in the Low N without clover treatment compared with all other treatments. At the phenotypic contrast level, the main effect of perennial ryegrass heading date on white clover content was significant in four of the nine seasonal data sets available: on these occasions, mixtures based on mid-season heading cultivars had higher clover content than later season-heading cultivars. However, this difference was not sufficient to cause any clover × cultivar interactions in herbage accumulation. Hence, the hypothesis that relative yield rankings of ryegrass cultivars do not differ when ryegrass is grown in monoculture or in mixture with white clover is supported. [ABSTRACT FROM AUTHOR]

The development of economic indexing systems for ranking cultivars of forage species requires new knowledge of factors that may influence the scaling of agronomic data collected in controlled, small-plot evaluation trials to whole farm systems. In the case of perennial ryegrass indexing, one such knowledge gap is the effect of growing clover with ryegrass on the relative rankings of different ryegrass cultivars. The objective of the investigation reported in this series was to test whether the relative yield rankings of perennial ryegrass (Lolium perenne L.) cultivars representing the range in phenotypes now available to New Zealand farmers as a result of recent breeding differed when those cultivars were grown in monocultures (as per standard protocols for cultivar yield trialling systems such as the National Forage Variety Trials) versus mixtures of grass and clover. This paper presents the rationale for the investigation by reviewing developments in perennial ryegrass breeding and evaluation in the context of grass-clover relationships in grazed pasture systems. The papers that follow report results from a multi-year, multi-site investigation comparing the yield, nutritive value and other productivity-related variables of eight perennial ryegrass cultivars grown with or without white clover (monoculture versus mixture respectively) at two levels of nitrogen fertiliser. Key considerations in the design of the experiment on which the investigation was based are discussed. [ABSTRACT FROM AUTHOR]

Results of studies designed to determine whether or not differences measured among perennial ryegrass cultivars in small-plot studies translate into differences in milk production and profit in dairy whole-system studies were reviewed. Only three experiments were identified that met the criteria for fully self-contained systems repeated over multiple years required to account for annual feed supply-demand balance, its interaction with animal intake and production, and the influence of inter-annual climate variability on these processes. Collectively, these studies provide evidence of improvement in animal production, associated with genetic gains from ryegrass breeding, albeit through shifts in factors such as heading date (as it affects herbage quality and grazing efficiency) and host plant by endophyte interactions, rather than through gains in dry-matter yield. The latter remains unresolved, despite substantial evidence for gains from small-plot trials of dry-matter yield increases in the order of 0.5% per annum. These studies also highlighted the number of factors that have to be taken into account in the design and conduct of such studies, including gaining clarity about the size of the differences that can be expected and ensuring sufficient statistical power. Implementing objective management rules that allow cultivars to express their potential and capture differences through the grazing animal will ensure sufficient measurement intensity to enable differences (if observed) in milk production and profit to be explained. This should guard against confounding factors such as the differential effects of insect pests on plant performance, and consequent changes in pasture botanical composition mediated by ryegrass endophyte strains. Despite these difficulties, more experiments of this type are required to quantify and, ultimately, increase the value being delivered by ryegrass breeding to pasture-based dairy production systems in temperate regions. Therefore, there is a need for whole-system studies to be undertaken to provide valuable new information and give farmers the confidence to invest in the use of new cultivars. [ABSTRACT FROM AUTHOR]

Abstract: Cirsium arvense (L.) Scop. is a perennial herb indigenous to Eurasia that is now present throughout temperate regions of the world where it is considered one of the worst weeds of pastoral and agricultural systems. Classical biological control has been attempted in both North America (NA) and New Zealand (NZ). However, nearly 50years after the first agent releases there are no indications of successful control. We review the status of the five agents deliberately released for control of C. arvense in NA and NZ, plus the species unintentionally introduced, and the occurrence of insects native to NA on C. arvense. We retrospectively evaluate C. arvense as a target weed, critique the agents selected for release, and contrast the different situations in NA and NZ. In retrospect, we see justification for the agents released in NA, but it is evident that these agents would not meet the more stringent host specificity requirements necessary to be released today. The failure of the program in NA is attributed to compromised safety, and lack of impact. Non-target impacts by one of the released agents, Rhinocyllus conicus, have raised safety concerns for native thistle plants. The other released agents either failed to establish, or if established, had no impact on the weed. In contrast, the situation in NZ is quite different because there are no related native thistles (Cardueae), and thus little chance of non-target impacts. Thus far, failure in NZ is attributed to lack of effectiveness due to non-establishment, or no impact, of released agents. In the past, the same agents that were released in NA were subsequently released in NZ, without considering whether or not these were the best choices. Thus, the past failure in NZ might be due to the previous lack of a NZ-specific approach to biocontrol of thistles in general and C. arvense in particular. A new approach taking into consideration the absence of native Cardueae has resulted in the release of agents more likely to be effective, and has potentially set NZ on track towards successful biological control of C. arvense, and other thistles. [Copyright &y& Elsevier]