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Xie S.,National University of Ireland | Frost J.P.,Hillsborough Co. | Lawlor P.G.,Teagasc | Wu G.,Tsinghua University | Zhan X.,National University of Ireland
Bioresource Technology | Year: 2011

Dried grass silage (GS) was pre-treated at different NaOH loading rates (1%, 2.5%, 5% and 7.5% by volatile solids (VS) mass in grass silage) and temperatures (20°C, 60°C, 100°C and 150°C) to determine effects on its bio-degradability in terms of the hydrolysis yield and degradation of ligno-cellulosic materials for biogas production. At 100°C and the four NaOH loadings, up to 45% of the total COD was solubilised and up to 65.6%, 36.1% and 21.2% of lignin, hemicellulose and cellulose were removed, respectively; biological methane production potentials obtained were 359.5, 401.8, 449.5 and 452.5ml CH 4/g VS added, respectively, being improved by 10-38.9% in comparison with untreated GS. VS removals following anaerobic digestion were 67.6%, 76.9%, 85.3%, 95.2% and 96.7% for untreated GS and GS treated at the four NaOH loadings, respectively. 100°C and the NaOH loading rate of 5% is recommended as a proper GS pre-treatment condition. © 2011 Elsevier Ltd.

Xie S.,National University of Ireland | Lawlor P.G.,Teagasc | Frost J.P.,Hillsborough Co. | Wu G.,Tsinghua University | Zhan X.,National University of Ireland
Bioresource Technology | Year: 2012

Hydrolysis and acidification of grass silage (GS) was examined in leaching bed reactors (LBRs) under organic loading rates (OLRs) of 0.5, 0.8 and 1.0kg volatile solids (VS)/m 3/day. The LBRs were run in duplicate over five consecutive batch tests (Batch tests 1-5) to examine the effects of pH, leachate dilution and addition of inoculum on the process of hydrolysis and acidification. The highest GS hydrolysis yields of 52-58%, acidification yields of 57-60% and VS removals of 62-66% were obtained in Batch test 4. Increasing OLRs affected the hydrolysis yield negatively. In Batch test 4, the reduction of lignocellulosic materials was up to 74.4% of hemicellulose, 30.1% of cellulose and 9.3% of lignin within 32days. Cellulase activity can be used as an indicator for the hydrolysis process. Methane production from the LBRs only accounted for 10.0-13.8% of the biological methane potential of GS. © 2012 Elsevier Ltd.

Xie S.,National University of Ireland | Xie S.,Teagasc | Wu G.,Tsinghua University | Lawlor P.G.,Teagasc | And 2 more authors.
Bioresource Technology | Year: 2012

Anaerobic co-digestion of the solid fraction of separated pig manure (SPM) with dried grass silage (DGS) was evaluated in three identical continuously stirred tank reactors (CSTRs) at 35±1°C. The feedstock contained 20% DGS in CSTR1, 30% DGS in CSTR2 and 40% DGS in CSTR3 on a volatile solids (VS) basis. Organic loading rates (OLR) of 1.0, 1.5, 2.0 and 3.0kgVS/m 3/d were studied and it was found that the OLR affected the digester performance more than the DGS proportion in the feedstock. Tripling the OLR increased volumetric methane yields by 88% and decreased specific methane yields by 38%. At the OLR of 3kgVS/m 3/d, post-methane production potentials of digestates ranged from 38% to 41% of total methane production potentials of the feedstock. An energy yield estimation on a 654-sow pig unit showed that 268-371MWh/a electricity and 383-530MWh/a heat would be generated. © 2011 Elsevier Ltd.

Munoz C.,Hillsborough Co. | Munoz C.,Institute Investigaciones Agropecuarias INIA Remehue | Yan T.,Hillsborough Co. | Wills D.A.,Hillsborough Co. | And 2 more authors.
Journal of Dairy Science | Year: 2012

The objectives of the present study were to compare the sulfur hexafluoride (SF6) and respiration chamber techniques for measuring methane (CH4) emissions from dairy cows and to determine the proportion of CH4 that is released through the rectum. Data used were derived from 20 early lactation dairy cows in a 2 × 2 factorial design study for 4 periods with 6 wk/period. The 4 treatment diets consisted of grass silage and 2 levels of concentrate (30 and 60% dry matter basis), with or without yeast supplement. At the end of each period, CH4 emissions were measured simultaneously using the SF6 and respiration chamber techniques when cows were housed in chambers. The SF6 technique was also used when cows were housed in digestibility units (barn location) before and after respiratory chamber measurements (chamber location). The simultaneous measurements in chamber location revealed that CH4 emission estimates by the SF6 technique were similar to those by the respiration chamber technique in the first 3 periods, although the SF6 estimates were significantly higher in period 4. The regression of all data from the 4 periods demonstrated a linear relationship between the SF6 and respiration chamber measurements for total CH4 emissions (g/d, R2=0.69) and for CH4 emissions per unit of milk yield (g/kg, R2=0.88), and a quadratic relationship for CH4 emissions per unit of dry matter intake (g/kg, R2=0.64). The CH4 emissions from the rectum were calculated as the difference between CH4 estimates from the SF6 technique when cows were housed in respiratory chambers and barn locations, which was 3% of the total CH4 emissions from the mouth, nostrils, and rectum. The SF6 estimates in the chamber location accounted for all sources of emissions, whereas those in the barn location, like that in grazing conditions, did not include CH4 emission from the rectum. Therefore, the SF6 measurements for grazing cattle should be adjusted for CH4 emissions from the rectum (3% of total). We conclude that the SF6 technique is reasonably accurate for estimating CH4 emissions. © 2012 American Dairy Science Association.

Annett R.W.,Hillsborough Co. | Carson A.F.,Hillsborough Co. | Dawson L.E.R.,Hillsborough Co. | Irwin D.,Hillsborough Co. | Kilpatrick D.J.,Bt Inc.
Animal | Year: 2011

The aim of this study was to evaluate the effects of age and breed on the reproductive performance and lamb output of crossbred hill ewes relative to purebred Scottish Blackface (BF). BF ewes were compared alongside Swaledale (SW)× BF, North Country Cheviot (CH) × BF, Lleyn (LL) × BF and Texel (T) × BF ewes on six commercial hill farms across Northern Ireland, on which all the ewes were born and reared. Ewes were mated to a range of sire breeds, balanced across breeds, for up to five successive breeding seasons. Mature live weight of adult BF, SW × BF, CH × BF, LL × BF and T × BF ewes was 52.8, 54.9, 60.3, 55.6 and 58.6 kg (P < 0.001), respectively. Compared with the pure BF, the number of lambs born per ewe lambed was higher with LL × BF and SW × BF (P < 0.05), whereas the number of lambs weaned per ewe lambed was greater for LL × BF and T BF × (P < 0.01). Total litter weight at birth of all the crossbred ewes was heavier (P < 0.01) than the pure BF, except in primiparous 2-year-old ewes. Lambs born to CH × BF and T × BF dams were 0.24 to 0.35 kg heavier at birth (P < 0.01) than the other ewe breeds, whereas lambs born to CH × BF, LL × BF and T × BF dams were, on average, 1.7, 1.3 and 1.5 kg, respectively, heavier (P < 0.01) at weaning than those from BF dams due to their higher (P < 0.05) average daily gain. Compared with the pure BF, total weaned lamb output per ewe lambed was 3.7, 4.8, 6.7 and 5.4 kg heavier (P < 0.05) for SW × BF, CH × BF, LL × BF and T × BF, respectively. However, as a result of the heavier live weight of the crossbred ewes, production efficiency (lamb output per kilogram live weight (W) and lamb output per kilogram metabolic live weight (W0.75)) was higher (P < 0.001) for LL × BF ewes only. For all ewe breeds, litter size at birth per ewe lambed, total lamb birth weight per ewe lambed and litter size at weaning increased (P < 0.001) with age up to 5 years, but decreased in 6-year-old ewes. Average lamb weaning weight and total weaned lamb output per ewe lambed increased (P < 0.001) with age up to 4 years. Production efficiency of the 6-year-old ewes was lower (P < 0.01) than the younger ewes. This study shows that adopting a flock replacement policy based on crossing BF ewes with LL, SW, T and CH sires can lead to significant improvements in the productivity of hill flocks. © The Animal Consortium 2011.

Speijers M.H.M.,Hillsborough Co. | Finney G.A.,Hillsborough Co. | McBride J.,Hillsborough Co. | Watson S.,Agri Food and Biosciences Institute of Northern Ireland | And 2 more authors.
Journal of Dairy Science | Year: 2012

Two experiments were conducted to test the effectiveness of different footbathing frequencies using CuSO4 in the control of digital dermatitis (DD) in groups of dairy cows with low and high DD prevalence in an endemically infected herd. During the study, groups of cows walked through allocated footbath solutions after milking on 4 consecutive milkings each week, 2 wk, or monthly, depending on treatment. The footbath solutions were changed either after 200 cows had passed through the footbath or within 24h. All cows were scored weekly during milking for DD lesion stage on the hind feet using a 5-point nominal scale. A transition grade was assigned based on whether the DD lesions improved (1) or deteriorated or did not improve (0) from week to week, and was averaged for all cows in the group. Furthermore, from the longitudinal study data, all transitions between different DD lesion stages between the different time points were used in a discrete, first-order Markov chain (state transition matrix) model. In experiment 1, 70 Holstein-Friesian cows with DD lesions present on at least one of their hind feet were allocated to 1 of 2 footbath treatments for 14 wk: (1) 5% CuSO4 each week or (2) 5% CuSO4 every 2 wk. At the end of the study, no active DD lesions were observed in cows in either treatment group, but significantly more cows had no DD lesions (0.48±0.097 vs. 0.24±0.094) and fewer cows had lesions in the healing stage (0.52±0.104 vs. 0.77±0.090) for the weekly compared with the 2-wk footbathing regimen. The number of active DD lesions that the transition matrix model predicted over time was 3 and 8% for weekly and every 2 wk footbathing treatments, respectively. In experiment 2, 64 cows with no DD lesions on either of their hind feet were allocated to 1 of 2 footbath treatment regimens for 14 wk: (1) 5% CuSO4 every 2 wk or (2) 5% CuSO4 each month. At the end of the trial, significantly more cows had no DD (0.80±0.088 vs. 0.65±0.102) and fewer cows had DD lesions in the healing stage (0.20±0.088 vs. 0.35±0.102) in the every 2 wk regimen than in the monthly footbathing regimen. The number of active DD lesions that the transition matrix model predicted over time was low for both footbathing interventions (1 and 4%, respectively). Increasing the interval between footbaths does not appear the most appropriate mechanism for reducing CuSO4 usage. © 2012 American Dairy Science Association.

Donaldson C.J.,Hillsborough Co. | Donaldson C.J.,Queen's University of Belfast | Ball M.E.E.,Hillsborough Co. | O'Connell N.E.,Queen's University of Belfast
Poultry Science | Year: 2012

The aim of this trial was to determine the effect of aerial perches on keel bone injuries and tibia bone characteristics in free-range laying hens. The relationship between keel bone injuries and individual bird parameters, such as weight, girth, wing:girth ratio, feather coverage, and tibia bone characteristics, was also assessed. Five commercial free-range houses, each containing between 7,000 and 8,000 birds, were used. The houses and range areas were divided in half; in half of the house, birds had access to aerial perches (P) and in the other half, they did not (NP). On 13 occasions between 17 and 70 wk of age, 20 birds per treatment were randomly selected from the slatted area and palpated for keel bone injury. At 72 wk of age, 30 birds per treatment in each of 4 houses were selected at random, weighed, and then euthanized. Girth and wing area and feather coverage were measured. The keel and left tibia bones were removed and keel bones were scored for injury. Tibia bones were weighed and diameter, length, breaking strength, and ash content recorded. Results indicated that access to aerial perches did not affect tibia bone measures (P > 0.05). Average palpated keel bone score increased with age of the hens (P < 0.001) but was not significantly affected by perch treatment (P > 0.05). There was a significant interaction between treatment and farm on keel bone injuries measured at dissection (P < 0.05), with the probability of birds having high keel-damage scores increasing in the perched treatment in some farms but not others. In general, as the keel bone injury score measured at dissection increased, the breaking strength (P < 0.001) and ash content (P < 0.05) of the tibia bone decreased. It is suggested that individual variation in bone strength contributes to differences in susceptibility to keel injury. No relationship existed between keel-injury score measured at dissection and individual parameters, such as weight, girth, or wing:girth ratio (P > 0.05), although feather coverage tended to decline with increasing keel damage (P < 0.06). © 2012 Poultry Science Association Inc.

Vance E.R.,Hillsborough Co. | Vance E.R.,Queen's University of Belfast | Ferris C.P.,Hillsborough Co. | Elliott C.T.,Queen's University of Belfast | And 2 more authors.
Journal of Dairy Science | Year: 2012

Although interest in crossbreeding within dairy systems has increased, the role of Jersey crossbred cows within high concentrate input systems has received little attention. This experiment was designed to examine the performance of Holstein-Friesian (HF) and Jersey × Holstein-Friesian (J × HF) cows within a high concentrate input total confinement system (CON) and a medium concentrate input grazing system (GRZ). Eighty spring-calving dairy cows were used in a 2 (cow genotype) × 2 (milk production system) factorial design experiment. The experiment commenced when cows calved and encompassed a full lactation. With GRZ, cows were offered diets containing grass silage and concentrates [70:30 dry matter (DM) ratio] until turnout, grazed grass plus 1.0. kg of concentrate/day during a 199-d grazing period, and grass silage and concentrates (75:25 DM ratio) following rehousing and until drying-off. With CON, cows were confined throughout the lactation and offered diets containing grass silage and concentrates (DM ratio; 40:60, 50:50, 40:40, and 75:25 during d 1 to 100, 101 to 200, 201 to 250, and 251 until drying-off, respectively). Full-lactation concentrate DM intakes were 791 and 2,905. kg/cow for systems GRZ and CON, respectively. Although HF cows had a higher lactation milk yield than J × HF cows, the latter produced milk with a higher fat and protein content, so that solids-corrected milk yield (SCM) was unaffected by genotype. Somatic cell score was higher with the J × HF cows. Throughout lactation, HF cows were on average 37. kg heavier than J × HF cows, whereas the J × HF cows had a higher body condition score. Within each system, food intake did not differ between genotypes, whereas full-lactation yields of milk, fat plus protein, and SCM were higher with CON than with GRZ. A significant genotype × environment interaction was observed for milk yield, and a trend was found for an interaction with SCM. Crossbred cows on CON gained more body condition than HF cows, and overall pregnancy rate was unaffected by either genotype or management system. In summary, milk and SCM yields were higher with CON than with GRZ, whereas genotype had no effect on SCM. However, HF cows exhibited a greater milk yield response and a trend toward a greater SCM yield response with increasing concentrate levels compared with the crossbred cows. © 2012 American Dairy Science Association.

Donaldson C.J.,Hillsborough Co. | Donaldson C.J.,Queen's University of Belfast | O'Connell N.E.,Queen's University of Belfast
Applied Animal Behaviour Science | Year: 2012

The aim of this trial was to determine the influence of aerial perches on welfare and production parameters in free-range laying hens. Five commercial free-range houses, each containing between 7000 and 8000 birds, were used. Each house and range area was split in half to create two treatments. In half of the house the birds had access to aerial perches (P) and in the other half they did not (NP). Perches were provided from the start of the lay cycle at 16 weeks of age, and remained in place until the end of the lay cycle (at approximately 74 weeks). Behavioural observations took place over two day periods at intervals between 17 and 70 weeks of age. During day 1, tests of fearfulness and observations of aggressive and feather pecking behaviours were performed. In addition, twenty birds per replicate were randomly selected and weight, body condition, feather coverage and resistance to handling were measured. The use of the range area by birds was assessed on day 2. The percentage of eggs laid out of nest boxes ('floor eggs') was recorded continuously on three of the farms, and egg quality was assessed from a sample of eggs every 10 weeks across the production cycle on all farms. Access to aerial perches significantly reduced the level of aggression in the slatted and litter areas of the house (P<0.05). P birds had a significantly lower flight distance from the observer than NP birds (P<0.05). In addition, NP birds resisted more to being handled than P birds (P<0.01). P birds were heavier (P<0.01) and had a greater body condition score (P<0.05) than NP birds. There was no effect of treatment on feather coverage (P>0.05), egg quality parameters (all P>0.05), or the proportion of floor eggs (P>0.05). In conclusion, these results suggest that the provision of aerial perches in commercial free-range farms leads to welfare benefits in terms of reduced fearfulness and aggression, and improved body condition. © 2012 Elsevier B.V.

This study investigated the performance and instrumental meat quality of finishing beef steers offered grass silage (GS), grass silage:maize silage (GS:MS) and grass silage:lupins/triticale silage (GS:LT). The lupins/triticale silage was grown as either two separate crops in the same field and harvested together (LT1) or grown and harvested as a mixture (LT2). The silages were offered to eighty continental cross beef steers, initial live weight 530 ± 47.7. kg and 18 ± 1.6 months of age and were supplemented with 3 or 6. kg concentrates fresh/head/d. Silage was fed ad libitum with the mixtures offered at a ratio of 60 GS:40 maize silage (MS), LT1 or LT2 on a dry matter (DM) basis and concentrates were offered once (3. kg) or twice (6. kg) daily on top of the silage. Animals were slaughtered in three batches after 100, 117 and 124. d on experiment. The LT1 and LT2 produced yields of 8.7 and 7.5. kg. DM/ha and the silages were poorly fermented as demonstrated by high ammonia-N concentration (182 and 173. g/kg total N), low lactic acid (9. g/kg DM) and high pH (5.0 and 4.7). Silage type had no significant effect on slaughter live weight, liveweight gain, carcass gain, forage DM intake (DMI), total DMI or feed efficiency expressed as kg. DMI/kg. liveweight gain or kg. DMI/kg. carcass gain. Silage type had no effect on carcass characteristics or instrumental meat quality. The results of this study demonstrate that offering lupins/triticale silage in combination with high quality grass silage (D-value greater than 700) at a ratio of 60 grass silage:40 LT1 or LT2 on a DM basis had no effect on animal performance, carcass characteristics or meat quality parameters relative to high quality grass silage offered alone or in combination with maize silage. © 2011.

Loading Hillsborough Co. collaborators
Loading Hillsborough Co. collaborators