F.J. Mulligan
University College Dublin
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Featured researches published by F.J. Mulligan.
Veterinary Journal | 2008
F.J. Mulligan; Michael L. Doherty
Production diseases of the dairy cow are caused by a level of production inconsistent with nutrient intake, provision of an inadequate diet, an unsuitable environment, an inappropriate breeding policy or various combinations of these factors. Although the transition period of 3 weeks pre-calving until 3 weeks post-calving is associated with a peak incidence of production disease, the effects of these diseases on dairy cow health and productivity extend far into the following lactation. Recent advances in understanding of production diseases include the emergence of propylene glycol and rumen protected choline as the supplements of choice for preventing fatty liver and the absence of any preventative effect of increased energy density in the close-up dry period diet on this condition; the linear negative influence of dietary cation anion difference (DCAD) on the incidence of milk fever regardless of urinary pH or the target level of dietary DCAD achieved; the inflammatory response associated with subacute rumen acidosis and its effect on feed intake; an increased awareness of the potential for antioxidant status to improve immunity and health in the transition period; the development of more standardised diagnostic criteria and treatment protocols for uterine infection. A significant body of knowledge already exists which should allow for the optimal management and prevention of bovine production diseases. One of the important challenges facing the dairy industry is the development, implementation and economic assessment of practical, integrated, blueprints of best practice for prevention of the production diseases and other diseases of the dairy cow.
Veterinary Journal | 2008
Luke O’Grady; Michael L. Doherty; F.J. Mulligan
Subacute ruminal acidosis (SARA) is a significant production disease of dairy cattle. Previous concerns have been raised over the occurrence of SARA in pasture-fed dairy cattle and the potential consequences of laminitis and lameness. Highly digestible perennial rye grass contains high concentrations of rapidly fermentable carbohydrate and low concentrations of physical effective fibre that may result in SARA. This study conducted a point prevalence survey of rumen health status in grazing Irish dairy cattle fed predominantly perennial rye grass-based pasture. The survey assessed rumen fluid, animal health status, milk production data and pasture composition. A total of 144 cows between 80 and 150 days in milk were sampled on 12 farms. Eleven percent of cows were classified as affected with SARA (pH < or = 5.5), 42% were marginal (pH 5.6-5.8) and 47% were normal (pH>5.8). The study showed that low rumen pH is prevalent in grazing Irish dairy cattle consuming perennial rye grass-based pasture and raises concerns regarding effective pasture utilisation and possible consequences for animal health.
Journal of Dairy Science | 2011
B.F. O’Neill; M.H. Deighton; B.M. O’Loughlin; F.J. Mulligan; T.M. Boland; M. O’Donovan; E. Lewis
The objective of the present study was to compare the enteric methane (CH4) emissions and milk production of spring-calving Holstein-Friesian cows offered either a grazed perennial ryegrass diet or a total mixed ration (TMR) diet for 10 wk in early lactation. Forty-eight spring-calving Holstein-Friesian dairy cows were randomly assigned to 1 of 2 nutritional treatments for 10 wk: 1) grass or 2) TMR. The grass group received an allocation of 17 kg of dry matter (DM) of grass per cow per day with a pre-grazing herbage mass of 1,492 kg of DM/ha. The TMR offered per cow per day was composed of maize silage (7.5 kg of DM), concentrate blend (8.6 kg of DM), grass silage (3.5 kg of DM), molasses (0.7 kg of DM), and straw (0.5 kg of DM). Daily CH4 emissions were determined via the emissions from ruminants using a calibrated tracer technique for 5 consecutive days during wk 4 and 10 of the study. Simultaneously, herbage dry matter intake (DMI) for the grass group was estimated using the n-alkane technique, whereas DMI for the TMR group was recorded using the Griffith Elder feeding system. Cows offered TMR had higher milk yield (29.5 vs. 21.1 kg/d), solids-corrected milk yield (27.7 vs. 20.1 kg/d), fat and protein (FP) yield (2.09 vs. 1.54 kg/d), bodyweight change (0.54 kg of gain/d vs. 0.37 kg of loss/d), and body condition score change (0.36 unit gain vs. 0.33 unit loss) than did the grass group over the course of the 10-wk study. Methane emissions were higher for the TMR group than the grass group (397 vs. 251 g/cow per day). The TMR group also emitted more CH4 per kg of FP (200 vs. 174 g/kg of FP) than did the grass group. They also emitted more CH4 per kg of DMI (20.28 vs. 18.06 g/kg of DMI) than did the grass group. In this study, spring-calving cows, consuming a high quality perennial ryegrass diet in the spring, produced less enteric CH4 emissions per cow, per unit of intake, and per unit of FP than did cows offered a standard TMR diet.
Livestock Production Science | 1999
F.P. O’Mara; F.J. Mulligan; E.J. Cronin; M. Rath; P.J Caffrey
Abstract The objectives of this experiment were to determine the in vivo digestibility of solvent extracted and expeller palm kernel meal (PKM) and to establish how well this was predicted by laboratory techniques. Eight samples of expeller PKM and four samples of solvent extracted PKM were collected over 4 years. Their in vivo digestibility was measured by total faecal collection using four wethers per sample. The laboratory methods for predicting digestibility were the in vitro rumen fluid (RF), neutral detergent cellulase with gammanase (NCG), and pepsin cellulase with gammanase (PCG) methods. Gammanase has been added to the latter two methods specifically to improve the prediction of digestibility of PKM. The solvent extracted samples had higher organic matter digestibility (691 vs. 653 g/kg, sed 15.7) and crude protein digestibility (727 vs. 597 g/kg, sed 36.6). However, the expeller samples had higher ( P =0.12) contents of digestible energy (13.4 vs. 12.5 MJ/kg DM, sed 0.48) due to their higher gross energies (20.6 vs. 19.1 MJ/kg DM). None of the laboratory digestibility tests predicted digestibility satisfactorily. The residual standard deviation was 29, 32 and 31 g/kg for the RF, NCG and PCG methods, respectively. In particular, two expeller samples and two solvent extracted samples were grossly underpredicted by the laboratory methods. These results indicate that PKM is a medium quality energy feed for ruminants and that enzymatic procedures including gammanase or the in vitro rumen fluid method do not accurately predict its digestibility.
Physiological Genomics | 2012
S.W. Walsh; Jai Prakash Mehta; Paul A. McGettigan; John A. Browne; Niamh Forde; Radwan M. Alibrahim; F.J. Mulligan; Brendan J. Loftus; M.A. Crowe; Daragh Matthews; M.G. Diskin; M. Mihm; A.C.O. Evans
Cellular mechanisms that contribute to low estradiol concentrations produced by the preovulatory ovarian follicle in cattle with a compromised metabolic status are largely unknown. To gain insight into the main metabolic mechanisms affecting preovulatory follicle function, two different animal models were used. Experiment 1 compared Holstein-Friesian nonlactating heifers (n = 17) and lactating cows (n = 16) at three stages of preovulatory follicle development: 1) newly selected dominant follicle in the luteal phase (Selection), 2) follicular phase before the LH surge (Differentiation), and 3) preovulatory phase after the LH surge (Luteinization). Experiment 2 compared newly selected dominant follicles in the luteal phase in beef heifers fed a diet of 1.2 times maintenance (M, n = 8) or 0.4 M (n = 11). Lactating cows and 0.4 M beef heifers had higher concentrations of β-hydroxybutyrate, and lower concentrations of glucose, insulin, and IGF-I compared with dairy heifers and 1.2 M beef heifers, respectively. In lactating cows this altered metabolic environment was associated with reduced dominant follicle estradiol and progesterone synthesis during Differentiation and Luteinization, respectively, and in 0.4 M beef heifers with reduced dominant follicle estradiol synthesis. Using a combination of RNA sequencing, Ingenuity Pathway Analysis, and qRT-PCR validation, we identified several important molecular markers involved in steroid biosynthesis, such as the expression of steroidogenic acute regulatory protein (STAR) within developing dominant follicles, to be downregulated by the catabolic state. Based on this, we propose that the adverse metabolic environment caused by lactation or nutritional restriction decreases preovulatory follicle function mainly by affecting cholesterol transport into the mitochondria to initiate steroidogenesis.
Livestock Production Science | 2001
F.J. Mulligan; P.J Caffrey; M. Rath; M.J. Kenny; F.P. O’Mara
The digestibility of concentrate feeds has been determined by difference using hay as a basal forage in many institutions. The objective of this experiment was to examine the effect of hay intake level and dietary crude protein (CP) content on hay digestibility. Groups of wether lambs (1 year old) were fed three levels (600, 700 and 800 g/day) of hay each at two CP contents (103 and 182 g CP/kg DM), achieved by using a urea solution. An extra group of lambs were fed hay unsupplemented with urea (42 g CP/kg DM) at a level of 800 g/day. The true organic matter digestibility (True OMD, calculated using two methods: True OMD 1 and 2) and apparent OMD of all treatments fed the 182 g CP/kg DM diets were significantly higher (P<0.05) than treatments fed the 103 g CP/kg DM diet (OMD: 632.8 g/kg vs. 604.2 g/kg; True OMD 1: 720.6 vs. 694.1 g/kg; True OMD 2: 711.8 vs. 681.0 g/kg). Apparent and true digestibility also increased as hay allowance increased and a significant linear effect was observed for GED. For the three groups fed 800 g/day of hay, significant differences in digestibility due to CP content only occurred between the 182 and the 42 g CP/kg DM diets (with the exception of CP digestibility). Although the effect of CP content was significant in some cases, the magnitude of the observed digestibility response is of little consequence for concentrate feed evaluation.
Livestock Production Science | 2002
F.J. Mulligan; J Quirke; M. Rath; P.J Caffrey; F.P. O’Mara
Abstract This experiment compares maize and grass silage in relation to dry matter (DM) intake, milk production and the kinetics of digestion and passage for both forages. Twenty-two multiparous late lactation dairy cows were fed diets based on maize or grass silage (diets MS and GS, respectively) for a period of 7 weeks. Milk production was determined over 4 weeks ( n =11 per treatment) with total diet digestibility, forage DM intake and rumen outflow rate being determined in tie stalls ( n =7 per treatment). Forage degradability characteristics were determined using three fistulated steers. The difference in forage DM intake between treatments was highly significant ( P P >0.05). However, cows fed the MS diet had a significantly higher milk fat and milk protein content and milk fat yield ( P
Livestock Production Science | 2001
F.J. Mulligan; P.J Caffrey; M. Rath; J. Callan; F.P. O’Mara
Abstract The aim of this work was to investigate the inter-relationships between feeding level, digestibility and rumen particulate and fluid turnover rate (k1p and k1f: % per hour) for high concentrate diets in cattle and sheep. In Experiment 1, four fistulated steers were used in a 4×4 Latin square experiment to determine k1p at high (12.45 kg/d) and low (6.48 kg/d) intakes using either Cr-mordanted soya hulls or Cr 2 O 3 as particulate markers. In the second and last period of this experiment, soya hulls digestibility and k1f were determined for each intake level. In Experiment 2, seven 1 year old wether sheep were used to determine the digestibility of soya hulls, k1p and k1f at high (907 g/d; n =3) and low (703 g/d; n =4) intakes. Increasing feeding level depressed DM, OM and GE digestibility ( P P P P P >0.10). For the pooled data set, linear relationships ( P P >0.05). These results indicate that depressions in digestibility at high feeding levels are associated with higher rumen turnover rates and that much of the variation in concentrate digestibility can be explained by changes in rumen turnover rate in both species.
Animal Reproduction Science | 2012
V. Gath; M.A. Crowe; D. O’Callaghan; M.P. Boland; P. Duffy; P. Lonergan; F.J. Mulligan
The objectives were to determine the effects of elevated blood urea concentrations on: (i) the response to superovulation, fertilisation rate, and early embryonic development in beef heifers, and (ii) embryo survival from days 7 to 35 of gestation. In Experiment 1, heifers (18-24 months) were allocated at random (n=20 per treatment) to one of the following diets: (i) ad libitum grass silage plus 5 kg commercial beef concentrates per day (controls); (ii) ad libitum grass silage plus 5 kg concentrates and 250 g feed grade urea per day (HE/HU); or (iii) ad libitum wheaten straw plus 250 g feed grade urea and 50 g vitamin/mineral mix per day (LE/HU). Serum urea concentrations were monitored throughout the experiment. Oestrus in heifers was synchronised using an intravaginal releasing device (CIDR(®), InterAg, New Zealand). Oestrus was detected and in vitro produced blastocysts (day 7, morphological grades 1 and 2) were transferred to the heifers 7 days later (19 days after start of treatment diets). The heifers were maintained on the dietary treatments for a further 28 days, when pregnancy status was determined by transrectal ultrasonography. Detected pregnancies were terminated using 15 mg luprostiol and recycled for Experiment 2. In Experiment 2, following a 14-day dietary rest period, the heifers were re-allocated at random to the three dietary treatments above. Heifers were treated with a CIDR for 8 days and 15 mg luprostiol was given 12h before pessary withdrawal. They received 144 mg pFSH (Folltropin(®)-V, Vetrepharm, Canada) given as 8 injections over 4 days commencing on day 6 of CIDR/dietary treatment. Heifers were artificially inseminated 48 h after progesterone pessary withdrawal using commercial semen of proven fertility by a competent inseminator. The heifers were maintained on their diets until slaughter, 3 days post insemination when corpora lutea numbers were determined and embryos were recovered and cell numbers determined visually. Serum urea concentrations were greater in heifers on LE/HU than in those on HE/HU diets, which in turn were greater than controls (7.1 ± 0.5, 4.9 ± 0.3 and 3.2 ± 0.1 mmol/L, respectively; P<0.05). There was no effect of diet type on pregnancy rate at day 35 (42%, 47% and 46%) and on the number of corpora lutea following superovulation (5.2 ± 0.8, 5.8 ± 1.5 and 6.8 ± 1.1) for heifers on control, HE/HU and LE/HU diets, respectively. The total number of embryos recovered per heifer was not different between the three groups (2.7 ± 0.6, 3.4 ± 1.1 and 4.8 ± 0.8 for heifers on control, HE/HU and LE/HU diets, respectively; P>0.05), but the number of embryos with 8 or more cells at recovery was greater in heifers on LE/HU than on control diets (3.4 ± 0.8 compared with 1.0 ± 0.3; P<0.05). However the percentage of embryos recovered with 8 or more cells was not different between groups (70.0 ± 13.3, 86.9 ± 7.2 and 76.5 ± 7.9%, for heifers on control, HE/HU and LE/HU diets respectively). Fertilisation rate, expressed as the proportion of embryos with more than one cell at recovery relative to the total number of embryos recovered, was less in the heifers on the control diet than in the other two dietary treatments (61.3 ± 11.8, 92.0 ± 3.5 and 86.8 ± 5.4% for heifers on control, HE/HU and LE/HU diets, respectively; P<0.05). Deleterious effects of urea on reproduction were not found, suggesting that adverse effects of urea are likely to take place at the early oocyte development stage prior to ovulation or fertilisation following an increase in protein intake.
Livestock Production Science | 2002
F.J. Mulligan; P.J Caffrey; M. Rath; J. Callan; P.O. Brophy; F.P. O’Mara
This experiment investigated the effect of feeding level on diet digestibility at two forage:concentrate ratios for diets containing grass silage. Four rumen fistulated Holstein–Friesian steers were used in a latin square experiment comprising a 2×2 factorial arrangement of treatments. Treatments were maintenance and 1.6×maintenance feeding level and 500 or 850 g of soya hulls/kg DM. Digestibility was determined by total collection, with fractional soya hulls (k1p) and fractional solute outflow rate (k1f) determined for the rumen using Cr-mordanted soya hulls and Co-EDTA, respectively. Rate of digestion was determined in-sacco. Increasing feeding level and soya hulls inclusion decreased diet DM, OM, CP, NDF, ADF and GE digestibility (P<0.01). The depression due to feeding level was greater for 850 g/kg DM soya hulls diets for GE (P<0.05), DM (P=0.06) and OM (P=0.06) digestibility. Rate of slowly degradable soya hulls DM and NDF digestion was lower (P<0.05 and P=0.07) for 850 g/kg DM soya hulls diets. Soya hulls k1p and k1f increased with feeding level but only the increase in k1f was significant (P<0.01). Diet OM, NDF and GE digestibility were positively related to rumen pH 6 h after feeding (P<0.01; R2=0.50 to 0.69). These results suggest that lower rumen pH values may be an important component of the larger digestibility depressions often observed for high concentrate diets.