A Comparison between Simulated Grazing, 2-Cut and 3-Cut Silage Management on the Performance of \u3cem\u3eLolium perenne\u3c/em\u3e L.

Internationally, the majority of grass cultivar evaluation protocols test the performance of cultivars under cutting managements with little or no exposure to animal stresses such as treading and plant pulling. In addition, the majority of these protocols test cultivars under 2 or 3 cut silage systems. Gilliland and Mann (2000) reported a difference in cultivar ranking between years and also between management systems when a severe (simulated grazing to 3 cm height) or lax (6 cm height) defoliation was applied to perennial ryegrass (Lolium perenne L.) cultivars in plot trials. Internationally, many evaluation protocols use only one management system within the protocol, whereby defoliation height is constant. If the protocol applied is not similar to the grazing manage-ment imposed at farm level, then it is unclear if the protocol can identify the cultivars which are most suitable to a particular production system

Reaching A Verdict: The impact of minimum sentencing

The so-called ‘temporary’ minimum sentencing legislation introduced into South African law in 1998 is still in place. The legislation was passed largely in response to high crime rates at the time and the perceived leniency of the courts, and prescribes minimum sentences ranging from five years’ to life imprisonment for a variety of offences (including murder and rape and a range of other crimes, some of which are non-violent). Given the current furore over crime, it is highly likely that in April this year the legislation will be renewed for another year. But what has the impact of the legislation been and what legislative changes should be considered

Comparing Drying Protocols for Perennial Ryegrass Samples in Preparation for Chemical Analysis

Diet formulation for animals requires accurate estimation of feed nutritive value. In order to determine the nutritive value of grass, the moisture in the samples must be removed, with minimum damage to cell structure, and then the dried samples milled, prior to chemical analysis. Generally samples are oven dried. The aim of this study was to verify if differing drying protocols gave diverging results when drying grass samples. The drying protocols investigated were 40°C for 48 hours, 60°C for 48 hours and 95°C for 15 hours in forced convection ovens. Four perennial ryegrass samples were cut to 4 cm from ground level on three occasions in 2012. On each occasion the four grass samples were mixed together thoroughly and divided into four replicates. Each replicate was divided into three sub-samples to give one 100 g-sample per drying treatment. At regular intervals the samples were removed from the oven and the weight recorded. The data were analysed using a mixed model repeated measures procedure in SAS. Time (hours) was used as the repeated measure. A separate dataset of 12 grass samples were dried using both the 40°C and 60°C protocols and then chemically analysed. This dataset was analysed using PROC GLM in SAS. Samples were assumed dry when there was no significant difference in weight between times. All drying protocols gave a similar final dry matter of approximately 156 g/kg. All drying protocols did dry the grass samples adequately as samples dried at 40°C and 60°C were not significantly lighter after 24 hours and samples dried at 95°C were not significantly lighter after 15 hours. There were no differences in ash or crude protein concentration of the samples dried using the 40°C and 60°C protocols. There were differences in the organic matter digestibility, neutral detergent fibre and acid detergent fibre concentrations between the grass samples dried using the different drying protocols

Cultivar Influences Milk Production of Grazing Dairy Cows

Perennial ryegrass is considered one of the most important forage grass species used in temperate ruminant animal production systems. Maximizing milk production from grazed grass is a major objective of pastoral-based dairy systems. While DM yield is an important trait, it fails to define the ultimate value of a grass cultivar, which is its potential to improve animal performance from a pasture sward (Reed 1994). The majority of cultivar evaluation trials are conducted under cutting, so therefore inferior cultivars from an animal production perspective may not be identified until commercialisation when animals graze a pasture sward. Reed (1978) reported that ryegrass pastures of similar digestibility can have different animal production responses depending on the season. Without exposure to animal production trials, practical differences between cultivars under field conditions may not be detected. The objective of the current study was to evaluate the effect of four perennial ryegrass cultivars with different sward characteristics on milk yield, milk composition and dry matter intake (DMI) of lactating dairy cows during the spring and mid-season period

Immediate and Carryover Effects of Post-Grazing Sward Height Imposed in Early Spring on Sward and Milk Production

A grazing experiment was undertaken to investigate the immediate and carryover effect of post-grazing sward height (PGH) in early spring on sward and dairy cow production. Ninety Holstein-Friesian spring calving dairy cows were randomly assigned across 3 PGH treatments: 2.7, 3.5 and 4.2 cm from February 14 to April 24, 2011. Following the experimental period animals were managed similarly until the end of the lactation. Grazing to 2.7 cm during the experimental period reduced milk (-159 kg/cow; P \u3c 0.01) and milk solids (-16 kg/cow; P \u3c 0.01) yields and increased BW loss (+13 kg loss; P \u3c 0.05) when compared to the 3.5 and 4.2 cm treatments which performed similarly. Grass utilisation (\u3e2.7 cm) increased (P \u3c 0.001) by decreasing PGH from 4.2 cm (0.74) to 3.5 cm (0.82) and further to 2.7 cm (0.94). During the carryover period (April 24 to November 13), cumulative milk (3542 kg/cow) and milk solids (281 kg/cow) yields did not differ between the experimental treatments. End BW was similar across treatments (503 kg). Total lactation performance of cows grazing to 2.7 cm in spring was -24 kg milk solids (P \u3c 0.05) than the total lactation production of the 3.5 and 4.2 cm treatments (405 kg milk solids) indicating that cows offered a restricted pasture allowance in early lactation do not recover lost production. This study recommends a PGH of 3.5 cm in the first 2 grazing rotations to achieve a compromise between sward utilisation and animal performance in early spring while also ensuring high subsequent lactation milk production

Short-Term Milk Yield Response to Changes in Post-Grazing Sward Height

In temperate climates, grazed grass is the cheapest source of nutrients for the dairy cow (Finneran et al. 2010), therefore its utilisation should be optimised throughout the grazing season to increase enterprise profitability (Shalloo et al. 2004). Within spring-calving systems, energy requirements increase for the post-parturient dairy cow during the spring period. On the other hand, spring grass supply can be limited given low over-winter grass growth rates. The imposition of a lower post-grazing sward height (PGH) during this critical time may be a viable solution to increase grass availability. As the season progresses, PGH may be increased or decreased to adjust the allowance of grass in the dairy cow’s diet depending on farm grass supply. Quantifying the variation in animal production with changes in PGH will inform such decisions. Currently, there is no information available on the milk production response to changes in PGH over a short period of the lactation. Therefore, the aim of this experiment was to determine the short-term variation in milk yield (MY) and yields of protein, fat and lactose in response to changes in PGH around the tenth week of lactation of the spring calving dairy cow

Dry Matter Yield of Perennial Ryegrass Cultivars under Mechanical Cutting and Animal Grazing

Perennial ryegrass evaluation trials are essential to identifying and promoting the most productive cultivars for use at farm level to maximise sward productivity (Grogan and Gilliland 2011). Cultivar testing is predominantly conducted under simulated grazing trials to predict dry matter yield (DMY) performance under animal grazing. Previous studies have shown a high correlation in DMY between these two defoliation methods (Camlin and Stewart 1975; Creighton et al. 2010). In contrast, Binnie and Chestnutt (1991) demonstrated that swards grazed by animals had higher DMY performance than those exposed to simulated grazing managements. Animal pressures such as pulling, treading and nutrient return are not present in a simulated grazing management. The objective of this study was to determine if a relationship exists between the DMY of perennial ryegrass cultivars exposed to mechanical cutting compared to animal grazing

Utjecaj prinosa pašnjaka i pašnog obroka na kvalitetu travnjaka, unos paše i proizvodnju mlijeka.

Sixty-four Holstein-Friesian cows were randomly assigned to one of four treatments (M15, M20, H15 and H20) in a 2x2 factorial design, by considering: two pre-grazing pasture mass levels (PM, kg DM/ha): medium (M-1,600) vs. high (H-2,400); and two pasture allowance levels (PA, kg DM/cow/day): low (15) vs. high (20). Two periods (PI vs. PII) were studied. Sward density and pre-grazing sward height were higher in high compared to medium pre-grazing PM swards in PI (P<0.001, 255 vs. 235 kg DM/cm/ha and P<0.001, 14.8 vs. 10.9 cm, respectively) and PII (P<0.001, 216 vs. 196 kg DM/cm/ha and P<0.001, 14.3 vs. 13.0 cm, respectively). Lower post-grazing sward height and higher pasture utilization were obtained in low compared to high PA swards in PI (P<0.001, 4.1 vs. 4.9 cm and P<0.001, 98.8 vs. 89.9 %, respectively) and PII (P<0.001, 4.3 vs. 5.0 cm and P<0.001, 97.1 vs. 89.9 %, respectively). Pasture crude protein content and pasture organic matter digestibility were higher in medium compared to high pre-grazing PM swards in PI (P<0.001, 210 vs. 176 g/kg DM and P<0.05, 846 vs. 836 g/kg DM, respectively) and PII (P<0.05, 212 vs. 192 g/kg DM and P<0.05, 828 vs. 821 g/kg DM, respectively). This was due to higher leaf and lower dead proportions in medium than in high pre-grazing PM swards. Pasture dry matter intake (PDMI) (P<0.001, 16.5 vs. 14.7 kg DM/cow/day), milk yield (MY) (P<0.01, 23.8 vs. 22.7 kg/day) and milk solids yield (MSY) (P<0.05, 1.69 vs. 1.61 kg/cow) were higher in high compared to low PA swards in PI. Higher PDMI (P<0.001, 15.7 vs. 14.1 kg DM/cow/day), MY (P<0.001, 15.4 vs. 13.6 kg/day) and MSY (P<0.01, 1.19 vs. 1.08 kg/cow) were also found in high than in low PA swards in PII. The highest (P<0.001) milk output per ha (16,983 kg/ha) and milk solids per ha (1,268 kg/ha) were found in the group of dairy cows grazing in the M20 swards.Šezdeset četiri holštaj-frizijske krave nasumično su razvrstane u četiri skupine (M15, M20, H15 i H20), uzevši u obzir 2x2 faktorijalni dizajn s obzirom na: dvije razine prinosa pašnjaka prije napasivanja (PM, kg DM/ha) - srednja (M-1600) naprema visoka (H-2400), te dvije razine pašnog obroka (PA, kg DM / krava /dan) - niski (15) naprema visoki (20). Istražena su dva razdoblja (PI naprema PII). Između travnjaka s visokim i srednjim prinosom prije napasivanja (PM), u prvom razdoblju utvrđene su razlike s obzirom na gustoću travnjaka (P<0,001; H = 255 naprema M = 235 kg DM/cm/ha) i visinu trave (P<0,001; H = 14,8 naprema M = 10,9 cm). U drugom razdoblju, statistička značajnost i razlike između navedenih skupina iznosili su P<0,001; H = 216 naprema M = 196 kg DM/cm/ha i P<0,001; H = 14,3 naprema M = 13,0 cm. Najniža visina trave i najviša iskoristivost pašnjaka nakon napasivanja utvrđene su usporedbom niskog i visokog pašnog obroka tijekom prvog razdoblja (P<0,001; niski = 4,1 naprema visoki = 4,9 cm te P<0,001; niski = 98,8 naprema visoki = 89,9%) kao i tijekom drugog razdoblja (P<0,001; niski = 4,3 naprema visoki = 5,0 cm te P<0,001; niski = 97,1 naprema visoki = 89,9%). Sadržaj sirovih proteina i probavljivost organske tvari tijekom prvog razdoblja bili su viši kod pašnjaka sa srednjim prinosom pašnjaka prije napasivanja u odnosu na pašnjake s visokom razinom prinosa prije napasivanja (P<0,001; M = 210 naprema H = 176 g/kg DM i P<0,05; M = 846 naprema H = 836 g/kg DM. Tijekom drugog razdoblja, statistička značajnost i vrijednosti navedenih pokazatelja iznosili su (P<0,05; M = 212 naprema H = 192 g/kg DM i P<0,05; M = 828 naprema H = 821 g/kg DM). Navedeno se može pripisati većem udjelu lišća i manjem udjelu uvenule mase na pašnjacima sa srednjim prinosom prije napasivanja u odnosu na pašnjake s visokim prinosom prije napasivanja. Usporedba niskog i visokog pašnog obroka tijekom prvog razdoblja, pokazala je statistički značajne razlike za unos suhe tvari pašom (P<0,001; niski = 16,5 naprema visoki = 14,7 kg DM/krava/dnevno), proizvodnju mlijeka (P<0,01; niski = 23,8 naprema. visoki = 22,7 kg/day) te proizvodnju krute tvari mlijeka (P<0,05; niski = 1,69 naprema. visoki = 1,61 kg/krava). Tijekom drugog razdoblja, viši unos suhe tvari pašom utvrđen kod visokoga pašnog obroka u odnosu na niski pašni obrok (P<0,001; visoki = 15,7 naprema niski = 14,1 kg DM/krava/dnevno), viša je bila i proizvodnja mlijeka (P<0,001; visoki = 15,4 naprema niski = 13,6 kg/day) te proizvodnja krute tvari mlijeka (P<0,01; visoki = 1,19 naprema niski = 1,08 kg/krava). Najviša proizvodnja mlijeka po hektaru (P<0,001; 16,983 kg/ha) i krute tvari mlijeka po hektaru (1,268 kg/ha) utvrđena je kod krava koje su napasivane u skupini M20 travnjaka

Utjecaj prinosa pašnjaka i pašnog obroka na kvalitetu travnjaka, unos paše i proizvodnju mlijeka.

Sixty-four Holstein-Friesian cows were randomly assigned to one of four treatments (M15, M20, H15 and H20) in a 2x2 factorial design, by considering: two pre-grazing pasture mass levels (PM, kg DM/ha): medium (M-1,600) vs. high (H-2,400); and two pasture allowance levels (PA, kg DM/cow/day): low (15) vs. high (20). Two periods (PI vs. PII) were studied. Sward density and pre-grazing sward height were higher in high compared to medium pre-grazing PM swards in PI (P<0.001, 255 vs. 235 kg DM/cm/ha and P<0.001, 14.8 vs. 10.9 cm, respectively) and PII (P<0.001, 216 vs. 196 kg DM/cm/ha and P<0.001, 14.3 vs. 13.0 cm, respectively). Lower post-grazing sward height and higher pasture utilization were obtained in low compared to high PA swards in PI (P<0.001, 4.1 vs. 4.9 cm and P<0.001, 98.8 vs. 89.9 %, respectively) and PII (P<0.001, 4.3 vs. 5.0 cm and P<0.001, 97.1 vs. 89.9 %, respectively). Pasture crude protein content and pasture organic matter digestibility were higher in medium compared to high pre-grazing PM swards in PI (P<0.001, 210 vs. 176 g/kg DM and P<0.05, 846 vs. 836 g/kg DM, respectively) and PII (P<0.05, 212 vs. 192 g/kg DM and P<0.05, 828 vs. 821 g/kg DM, respectively). This was due to higher leaf and lower dead proportions in medium than in high pre-grazing PM swards. Pasture dry matter intake (PDMI) (P<0.001, 16.5 vs. 14.7 kg DM/cow/day), milk yield (MY) (P<0.01, 23.8 vs. 22.7 kg/day) and milk solids yield (MSY) (P<0.05, 1.69 vs. 1.61 kg/cow) were higher in high compared to low PA swards in PI. Higher PDMI (P<0.001, 15.7 vs. 14.1 kg DM/cow/day), MY (P<0.001, 15.4 vs. 13.6 kg/day) and MSY (P<0.01, 1.19 vs. 1.08 kg/cow) were also found in high than in low PA swards in PII. The highest (P<0.001) milk output per ha (16,983 kg/ha) and milk solids per ha (1,268 kg/ha) were found in the group of dairy cows grazing in the M20 swards.Šezdeset četiri holštaj-frizijske krave nasumično su razvrstane u četiri skupine (M15, M20, H15 i H20), uzevši u obzir 2x2 faktorijalni dizajn s obzirom na: dvije razine prinosa pašnjaka prije napasivanja (PM, kg DM/ha) - srednja (M-1600) naprema visoka (H-2400), te dvije razine pašnog obroka (PA, kg DM / krava /dan) - niski (15) naprema visoki (20). Istražena su dva razdoblja (PI naprema PII). Između travnjaka s visokim i srednjim prinosom prije napasivanja (PM), u prvom razdoblju utvrđene su razlike s obzirom na gustoću travnjaka (P<0,001; H = 255 naprema M = 235 kg DM/cm/ha) i visinu trave (P<0,001; H = 14,8 naprema M = 10,9 cm). U drugom razdoblju, statistička značajnost i razlike između navedenih skupina iznosili su P<0,001; H = 216 naprema M = 196 kg DM/cm/ha i P<0,001; H = 14,3 naprema M = 13,0 cm. Najniža visina trave i najviša iskoristivost pašnjaka nakon napasivanja utvrđene su usporedbom niskog i visokog pašnog obroka tijekom prvog razdoblja (P<0,001; niski = 4,1 naprema visoki = 4,9 cm te P<0,001; niski = 98,8 naprema visoki = 89,9%) kao i tijekom drugog razdoblja (P<0,001; niski = 4,3 naprema visoki = 5,0 cm te P<0,001; niski = 97,1 naprema visoki = 89,9%). Sadržaj sirovih proteina i probavljivost organske tvari tijekom prvog razdoblja bili su viši kod pašnjaka sa srednjim prinosom pašnjaka prije napasivanja u odnosu na pašnjake s visokom razinom prinosa prije napasivanja (P<0,001; M = 210 naprema H = 176 g/kg DM i P<0,05; M = 846 naprema H = 836 g/kg DM. Tijekom drugog razdoblja, statistička značajnost i vrijednosti navedenih pokazatelja iznosili su (P<0,05; M = 212 naprema H = 192 g/kg DM i P<0,05; M = 828 naprema H = 821 g/kg DM). Navedeno se može pripisati većem udjelu lišća i manjem udjelu uvenule mase na pašnjacima sa srednjim prinosom prije napasivanja u odnosu na pašnjake s visokim prinosom prije napasivanja. Usporedba niskog i visokog pašnog obroka tijekom prvog razdoblja, pokazala je statistički značajne razlike za unos suhe tvari pašom (P<0,001; niski = 16,5 naprema visoki = 14,7 kg DM/krava/dnevno), proizvodnju mlijeka (P<0,01; niski = 23,8 naprema. visoki = 22,7 kg/day) te proizvodnju krute tvari mlijeka (P<0,05; niski = 1,69 naprema. visoki = 1,61 kg/krava). Tijekom drugog razdoblja, viši unos suhe tvari pašom utvrđen kod visokoga pašnog obroka u odnosu na niski pašni obrok (P<0,001; visoki = 15,7 naprema niski = 14,1 kg DM/krava/dnevno), viša je bila i proizvodnja mlijeka (P<0,001; visoki = 15,4 naprema niski = 13,6 kg/day) te proizvodnja krute tvari mlijeka (P<0,01; visoki = 1,19 naprema niski = 1,08 kg/krava). Najviša proizvodnja mlijeka po hektaru (P<0,001; 16,983 kg/ha) i krute tvari mlijeka po hektaru (1,268 kg/ha) utvrđena je kod krava koje su napasivane u skupini M20 travnjaka

Variation in Grazing Sward Chicory Content After Periods of Low Rainfall

Multispecies (MS) swards can reduce chemical nitrogen (N) fertiliser requirement due to the legume components of the sward mixtures, and have the potential to increase drought tolerance, particularly where chicory (CH, Chicorium intybus L.) is included in the sward mixture. A grazed plot experiment was established to investigate the persistency of forage herb species in MS swards under typical Irish grazing conditions. The swards contained three plant functional groups: grass, legume and herb; four sward types were established which included sward mixtures of the following species: perennial ryegrass (PRG, Lolium perenne L.) white clover (WC, Trifolium repens L.), red clover (RC, Trifolium pratense L.), CH and ribwort plantain (PL, Plantago lanceolata L.). The sward content of the various species in the sown mixtures was evaluated over three years (2020, 2021 and 2022). The summer of 2022 experienced dry weather conditions in which rainfall was well below average thus providing an opportunity to assess the drought tolerance of CH in grazed swards. The proportion of sward CH content from two late season cuts was assessed over the three years and this study reports the changes in sward CH content between years and grazing rotations. Average sward CH content was 14.7, 6.1, and 1.5% across all sward types in late summer of 2020, 2021 and 2022, respectively; average sward CH content was 13.7, 9.4 and 24.6 across all sward types in autumn of 2020, 2021 and 2022, respectively