Milk production declines as dairy cows enter late lactation, resulting in reduced milk quality and negatively impacting milk processability, such as rennet coagulation time (RCT), milk pH and ethanol stability (ES), leading to seasonality issues for milk processors. Multispecies forages, containing grass, legume and herb species, require lower N inputs and are of interest to dairy farmers. However, little is known about the effect of grazing multispecies forages on milk processability characteristics in late lactation dairy cows. Forty-five autumn-calving dairy cows in late lactation were allocated to 1 of 3 grazing forages; perennial ryegrass (PRG; Lolium perenne), perennial ryegrass and white clover (Trifolium pratense) (PRGWC), and a 6 – species multispecies forage (MULTI) containing perennial ryegrass, timothy (Phleum pratense), white clover, red clover (Trifolium repens), chicory (Cichorium intybus) and plantain (Plantago lanceolata). Cows were allocated 12 kg DM grazed forage and supplemented with a grass – silage TMR and concentrate. Forage DMI was significantly lower for cows grazing PRG. Milk yield increased when cows grazed PRGWC (18.07 kg/d) and MULTI (17.84 kg/d) compared to PRG (16.08 kg/d). Milk RCT (mins) and ES (%) were unaffected by treatment. However, offering cows PRGWC and MULTI increased the concentration of C18:2 cis – 9, 12 and C18:3 cis – 9, 12, 15 in milk compared to PRG. Compared to PRG, grazing forages containing clover and herb species improved milk yield and beneficially altered milk fatty acid profile in late lactation dairy cows without negatively impacting milk processability.

To overcome grass supply shortages on the main grazing block, some pasture-based dairy farmers are using zero-grazing (also known as ‘cut and carry’), whereby cows are periodically housed and fed fresh grass harvested from external land blocks. To determine the effect of zero-grazing on cow performance, two early-lactation experiments were conducted with autumn and spring-calving dairy cows. Cows were assigned to one of two treatments in a randomized complete block design. The two treatments were zero-grazing (ZG) and grazing (G). The ZG group were housed and fed zero-grazed grass, while the G group grazed outdoors at pasture. Both treatments were fed perennial ryegrass (Lolium perenne L.) from the same paddock. In experiment 1, 24 Holstein Friesian cows (n = 12) were studied over a 35-day experimental period in autumn and offered fresh grass, grass silage, ground maize and concentrates. In experiment 2, 30 Holstein Friesian cows (n = 15) were studied over a 42-day experimental period and offered fresh grass and concentrates. Average dry matter intake and milk yield was similar for ZG and G in both experiments. Likewise, ZG did not have an effect on milk composition, body condition or locomotion. Zero-grazing had no effect on total nitrogen excretion or nitrogen utilization efficiency in either experiment, or on rumen pH and ammonia concentration in experiment 1. While zero-grazing may enable farmers to supply fresh grass to early-lactation cows in spring and autumn, results from this study suggest that there are no additional benefits to cow performance in comparison to well-managed grazed grass.

Since 1 April 2015, European dairy milk quotas have been removed resulting in the intensification of dairy production within EU countries. The aim of this study was to evaluate the physical and economic impacts of the initial intensification undertaken within Irish grazing dairy systems. Physical and financial data for 868 seasonal calving dairy farmers with records for each of the years 2013–2017 inclusive were used in this analysis. All analyses were undertaken using a mixed-model framework in PROC MIXED. The overall level of fat plus protein productivity of studied farms increased by 51% during the 5-year period through a combination of increased production per cow, increased operational scale and system intensification. Overall farm net profit was highly variable between years and was greatest in 2017 (€133 836) and least in 2016 (€65 176). When farms were characterized into milk production expansion quartiles, farms in Q1, Q2, Q3 and Q4 increased output by +7, +25, +44 and +86%, respectively. Whereas total farm profit (€/farm) declined for Q1 farms between 2013/2014 and 2016/2017 (€−5257; −7%), the greater expansion undertaken in Q2, Q3 and Q4 resulted in increases of €3046 (+4%), €20 810 (+25%) and €51 604 (+62%), respectively. In all strategies studied, farm profit increased due to a combination of increased revenues, increased pasture utilization and a dilution of per unit production costs. Further investigation of the longer term impacts of expansion is merited, not just in terms of economic indicators, but also in terms of environmental and socio-cultural change.

Rubber seed oil (RO) that is rich in polyunsaturated fatty acids (FA) can improve milk production and milk FA profiles of dairy cows; however, the responses of digestion and ruminal fermentation to RO supplementation in vivo are still unknown. This experiment was conducted to investigate the effect of RO and flaxseed oil (FO) supplementation on nutrients digestibility, rumen fermentation parameters and rumen FA profile of dairy cows. Forty-eight mid-lactation Holstein dairy cows were randomly assigned to one of four treatments for 8 weeks, including basal diet (CON) or the basal dietary supplemented with 4% RO, 4% FO or 2% RO plus 2% FO on a DM basis. Compared with CON, dietary oil supplementation improved the total tract apparent digestibility of DM, neutral detergent fibre and ether extracts ( P < 0.05). Oil treatment groups had no effects on ruminal digesta pH value, ammonia N and microbial crude protein ( P > 0.05), whereas oil groups significantly changed the volatile fatty acid (VFA) profile by increasing the proportion of propionate whilst decreasing total VFA concentration, the proportion of acetate and the ratio of acetate to propionate ( P < 0.05). However, there were no differences in VFA proportions between the three oil groups (P > 0.05). In addition, dietary oil supplementation increased the total unsaturated FA proportion in the rumen by enhancing the proportion of trans-11 C18:1 vaccenic acid (VA), cis-9, trans-11 conjugated linoleic acid (CLA) and α-linolenic acid (ALA) ( P < 0.05). These results indicate that dietary supplementation with RO and FO could improve nutrients digestibility, ruminal fermentation and ruminal FA profile by enhancing the VA, cis-9, trans-11 CLA and ALA composition of lactating dairy cows. These findings provide a theoretical basis for the application of RO in livestock production.

Background: Neuropsychological studies of the pattern and extent of cognitive impairment in HIV-infected patients have mostly used deviations from control values and/or cut-off scores as criteria for classification of dementia. There is, however, no agreement as to how to define impairment, and classification is imprecise. Method: The current study used a dementia classification matrix, developed with a step-wise linear discriminant analysis of neuropsychological data from patients with primary neurodegenerative dementias, to classify symptomatic HIV patients as demented or non-demented, and further to differentiate cortical and subcortical dementia patterns. Thirty-two male and 2 female patients (mean age 39 ± 2) with symptomatic HIV disease (mean absolute CD4 count 195 ±41) participated in the study. Results: Thirty-five per cent of patients were classified as demented. Of these, 83% showed a subcortical pattern and 17% a cortical profile of deficits. Significant differences between patients classified as subcortically demented and those categorized as normal on neuropsychological measures associated with subcortical integrity further validated the classification. Measures of psychiatric status between subgroups were similar. Conclusion: Since certain treatments may delay or reverse cognitive deficits, the use of an objective classification method based on discriminant analysis may help to identify patients who may benefit from therapy.

Cephalopods (Mollusca: Cephalopoda) play an important role as keystone invertebrates in various marine ecosystems, as well as being a valuable fisheries resource. At the World Malacological Congress, held 21–28 July 2013 in Ponta Delgada, Azores, Portugal, a number of cephalopod experts convened to honour the contribution of the late Malcolm R. Clarke, FRS (1930–2013) to cephalopod research. Endorsed by the Cephalopod International Advisory Council (CIAC), the meeting discussed some of the major challenges that cephalopod research will face in the future. These challenges were identified as follows: (1) to find new ways to ascertain the trophic role and food web links of cephalopods using hard tissues, stable isotopes and novel concepts in theoretical ecology; (2) to explore new approaches to the study of cephalopod morphology; (3) to further develop cephalopod aquaculture research; (4) to find new ways to ascertain cephalopod adaptation and response to environmental change; (5) to strengthen cephalopod genetics research; and (6) to develop new approaches for cephalopod fisheries and conservation. The present paper presents brief reviews on these topics, followed by a discussion of the general challenges that cephalopod research is bound to face in the near future. By contributing to initiatives both within CIAC and independent of CIAC, the principle aim of the paper is to stimulate future cephalopod research.

Nitrogen (N) losses from dairy production systems are a cause for environmental concern. Excreted primarily as urea N in the urine, this volatile form of N can be lost as ammonia (NH3) contributing to ground-level ozone, the greenhouse effect and the deterioration of terrestrial and aquatic ecosystems. In addition, the production of urea N places a metabolic demand for energy on the dairy cow and excessively high levels of blood urea N are known to have deleterious effects on reproductive performance. Therefore, it is of interest to develop strategies that reduce N excretion from dairy cows and to this end, dietary manipulation of N efficiency offers great potential. There are a significant number of reports in the literature on N efficiency in the lactating dairy cow, including reducing dietary CP intake, improving the balance of amino acids reaching the small intestine, optimising the forage mix and optimising the energy sources in the diet. Across these experiments, N intake ranged from 0.33 to 0.67 kg/day with N efficiency ranging from 0.21 to 0.42. This paper will report on recent N balance experiments conducted at University College Dublin, as well as reports in the literature on studies aimed at improving N efficiency in the lactating dairy cow.

The effective use of model-based formal methods in the development of complex embedded systems requires the integration of discrete-event models of controllers with continuous-time models of their environments. This paper proposes a new approach to the development of such combined models (co-models), in which an initial discrete-event model may include approximations of continuous-time behaviour that can subsequently be replaced by couplings to continuous-time models. An operational semantics of co-simulation allows the discrete and continuous models to run on their respective simulators and managed by a coordinating co-simulation engine. This permits the exploration of the composite co-model's behaviour in a range of operational scenarios. The approach has been realised using the Vienna Development Method (VDM) as the discrete-event formalism, and 20-sim as the continuous-time framework, and has been applied successfully to a case study based on the distributed controller for a personal transporter device.

β-Glucans have been identified as natural biomolecules with immunomodulatory activity. The first objective of the present study was to compare the effects of purified β-glucans derived from Laminariadigitata, L. hyperborea and Saccharomyces cerevisiae on piglet performance, selected bacterial populations and intestinal volatile fatty acid (VFA) production. The second aim was to compare the gene expression profiles of the markers of pro- and anti-inflammation in both unchallenged and lipopolysaccharide (LPS)-challenged ileal and colonic tissues. β-Glucans were included at 250 mg/kg in the diets. The β-glucans derived from L. hyperborea, L. digitata and S. cerevisiae all reduced the Enterobacteriaceae population (P < 0·05) without influencing the lactobacilli and bifidobacteria populations (P>0·05) in the ileum and colon. There was a significant interaction between gastrointestinal region and β-glucan source in the expression of cytokine markers, IL-1α (P < 0·001), IL-10 (P < 0·05), TNF-α (P < 0·05) and IL-17A (P < 0·001). β-Glucans did not stimulate any pro- or anti-inflammatory cytokine markers in the ileal epithelial cells. In contrast, the expression of a panel of pro- and anti-inflammatory cytokines (IL-1α, IL-10, TNF-α and IL-17A) was down-regulated in the colon following exposure to β-glucans from all the three sources. However, the data suggest that the soluble β-glucans derived from L. digitata may be acting via a different mechanism from the insoluble β-glucans derived from L. hyperborea and S. cerevisiae, as the VFA profile was different in the L. digitata-treated animals. There was an increase in IL-8 gene expression (P < 0·05) in the gastrointestinal tract from the animals exposed to L. digitata following an LPS ex vivo challenge that was not evident in the other two treatment groups. In conclusion, β-glucans from both seaweed and yeast sources reduce Enterobacteriaceae counts and pro-inflammatory markers in the colon, though the mechanisms of action may be different between the soluble and insoluble fibre sources.

The aim of this study was to assess the influence of age, body weight (BW) and body condition score (BCS) of maiden Holstein–Friesian heifers before mating start date (MSD) on the rate of puberty, subsequent production and longevity and their implications with regard to farm profitability. Data were available on 871 Holstein–Friesian heifers from 48 herds. BW was recorded electronically and BCS was recorded by a single operator on a scale of 1 to 5. Heifer age was calculated as the number of days from birth to the day of visit. All of the independent variables of interest were grouped into three or four categories. Three age categories (thirtiles), four BW categories (quartiles) and four BCS categories (⩽2.75, 3.00, 3.25 and ⩾3.50) were formed. Heifers with an identifiable corpus lutuem (CL) in the presence or absence of large follicles and peri-ovulatory signs and with a plasma progesterone (P4) concentration ⩾1 ng/ml were classified as pubertal. In addition, heifers without an identifiable CL in the presence or absence of large follicles and peri-ovulatory signs but with a P4 concentration ⩾1 ng/ml were also classified as pubertal. Age, BW and BCS at MSD were all found to be significantly associated with pubertal rate (P < 0.05). Age was shown to have no practical implications on subsequent cow performance. BW at MSD was favourably associated with subsequent calving date (P < 0.05), subsequent cow BW (P < 0.001) and potential (305 days) milk fat plus protein yield (P < 0.001). BCS at MSD was found to be favourably associated with milk fat plus protein yield potential (P < 0.05) and BCS (P < 0.001) during lactation. The economic analysis undertaken indicated that larger, well-grown heifers will be more profitable because of superior production potential, all else being equal. However, because of the finding of poorer reproductive efficiency in heifers grown to more than 343 kg at MSD, heifers at ∼330 kg at MSD are deemed optimal. This will correspond to mature cow BW of ∼550 kg.

The objective of this study is to quantify the milk production response per cow and per hectare (ha) for an incremental stocking rate (SR) change, based on a meta-analysis of published research papers. Suitable experiments for inclusion in the database required a comparison of at least two SRs under the same experimental conditions in addition to details on experimental length and milk production results per cow and per ha. Each additional increased SR treatment was also described in terms of the relative milk production change per cow and per ha compared to the lower base SR (b_SR). A database containing 109 experiments of various lengths with 131 comparisons of SR was sub-divided into Type I experiments (common experimental lengths) and Type II experiments (variable experimental lengths). Actual and proportional changes in milk production according to SR change were analysed using linear mixed model procedures with study included as a random effect in the model. Low residual standard errors indicated a good precision of the predictive equations with the exception of proportional change in milk production per cow. For all milk yield variables analysed, the results illustrate that while production per cow is reduced, a strong positive relationship exists between SR and milk production per ha. An SR increase of one cow/ha resulted in a decrease in daily milk yield per cow of 7.4% and 8.7% for Type I and Type II data, respectively, whereas milk yield per ha increased by 20.1% and 19.6%, respectively. Within the Type II data set, a one cow/ha increase in SR also resulted in a 15.1% reduction in lactation length (equivalent to 42 days). The low predictability of proportional change in milk production per cow according to the classical SR definition of cows per ha over a defined period suggests that SR may be more appropriately defined in terms of the change in available feed offered per animal within each treatment.

Two experiments, a performance experiment and a mineral balance study, were conducted on grower–finisher pigs (42 to 101 kg live weight) to investigate the effects of Peniophora lycii phytase enzyme and 25-hydroxyvitamin D3 (25-OHD3) on growth performance, carcass characteristics, nutrient retention and excretion, and bone and blood parameters. The two experiments were designed as a 2 × 2 factorial (two levels of phytase and two levels of 25-OHD3). The four diets were T1, low-phosphorous diet; T2, T1 + phytase; T3, T1 + 25-OHD3 and T4, T1 + phytase + 25-OHD3 diet. In all, 25 μg of 25-OHD3 was used to replace 1000 IU of vitamin D3 in diets T3 and T4. Diets were pelleted (70°C) and formulated to contain similar concentrations of energy (13.8 MJ DE/kg), lysine (9.5 g/kg) and digestible phosphorus (P; 1.8 g/kg). Neither the inclusion of phytase nor 25-OHD3 in the diet had any effect on pig performance. There was an interaction between phytase and 25-OHD3 on calcium (Ca) and P retention (P < 0.01) and on the apparent digestibility of ash (P < 0.01), P (P < 0.001) and Ca (P < 0.001). Pigs offered phytase diets only, had a higher retention of Ca and P and digestibility of ash (P < 0.01), P (P < 0.001) and Ca (P < 0.01) compared with pigs offered unsupplemented diets. However, when the combination of phytase and 25-OHD3 were offered, no effects were detected compared with 25-OHD3 diets only. Pigs fed phytase diets had higher bone ash (P < 0.01), bone P (P < 0.01) and bone Ca (P < 0.05) concentrations compared with pigs offered non-phytase diets. In conclusion, pigs offered phytase diets had a significantly increased bone ash, Ca and P than pigs offered unsupplemented phytase diets. However, there was no advantage to offering a combination of phytase and 25-OHD3 on either bone strength or mineral status compared to offering these feed additives separately.