• Effect of age and nutrient restriction pre partum on beef suckler cow serum immunoglobulin concentrations, colostrum yield, composition and immunoglobulin concentration and immune status of their progeny

      McGee, Mark; Drennan, Michael J; Caffrey, Patrick J. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effect of cow age (multiparous (MP) v. primiparous (PP)) and nutritional restriction pre partum (grass silage ad libitum v. straw only ad libitum for the last 15 (s.d. 3.3) days of gestation) on cow serum immunoglobulin (Ig) concentration, on colostrum yield, composition and Ig concentration and on calf serum Ig concentrations (at ~8 and 48 h post partum) using spring-calving Limousin Holstein-Friesian cows and their progeny was studied over 3 years. The method of colostrum administration (stomach tube vs. assisted suckling within 1 h post partum) on calf immune status was also investigated. When feeding colostrum the target was to give each calf 50 mL per kg birthweight via stomach tube. Colostrum yield and Ig concentration were measured following administration of oxytocin and hand-milking of half (Experiments 1 and 2) or the complete udder (Experiment 3). Following an 8-h period after birth during which suckling was prevented a further colostrum sample was obtained. There was no significant difference in first milking colostrum Ig subclass concentrations between the within-quarter fractions or between the front and rear quarters of the udder in either MP or PP cows. Colostrum Ig subclass concentrations at second milking were 0.46 to 0.65 of that at first milking. Compared to MP cows offered silage, colostrum yield and the mass of colostrum IgG1, IgG2, IgM, IgA and total Ig produced was lower (P < 0.001) for PP cows and the mass of IgG1, IgM and total Ig produced was lower (P < 0.05) for MP cows offered straw. Calves from PP cows and MP cows offered straw had significantly lower serum IgG1 and total Ig concentrations at 48 h post partum than calves from MP cows offered silage but there was no difference (P > 0.05) between colostrum feeding methods. In conclusion, calves from PP cows and MP cows offered straw had a lower humoral immune status than those from MP cows offered grass silage.
    • Effect of fumaric acid, calcium formate and mineral levels in diets on the intake and growth performance of newly weaned pigs

      Lawlor, Peadar G; Lynch, P Brendan; Caffrey, Patrick J. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The weaned pig has limited ability to acidify its stomach contents. The objective of this study (comprising three experiments) was to examine the effect of feeding diets containing fumaric acid (FA), calcium formate (CF) or diets of low acid binding capacity (ABC) on post-weaning pig performance. In all three experiments, pigs (10 per treatment) were weaned at 19 to 24 days, blocked on sex and weight and assigned at random to one of six treatments. In Experiment 1, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) low Ca (2.8 g/kg) and P (5.1 g/kg) (LCaP) diet for seven days followed by the control diet, (5) LCaP diet for seven days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control 15 g/kg CF. In Experiment 2, treatments were: (1) control diet, (2) control 20 g/kg FA, (3) control 15 g/kg CF, (4) LCaP diet for 14 days followed by the control diet, (5) LCaP diet for 14 days followed by control 20 g/kg FA, and (6) LCaP diet for seven days followed by control diet. In Experiment 3, treatments were: (1) high Ca (HC) diet (12 g/kg), (2) medium Ca (MC) diet (9 g/kg), (3) low Ca (LC) diet (6 g/kg), (4) HC 20 g/kg FA, (5) MC 20 g/kg FA, and (6) LC 20 g/kg FA. Pigs were individually fed for 26 days. In Experiment 1, CF tended to depress daily feed intake (DFI) in the final two weeks (691 v. 759 and 749, (s.e. 19) g/day, P = 0.07) and overall average daily gain (322 v. 343 and 361 (s.e. 11) g/day, P = 0.09) compared with the control and FA supplemented diets, respectively. Feeding diets with LCaP for seven days post weaning increased DFI (208 v. 178, (s.e. 8) g/day, P < 0.01) in week 1 and tended to improve feed conversion rate in the first two weeks (1.65 v. 1.85, s.e. 0.10, P = 0.09). In Experiment 2, treatment had no significant effect on pig performance but feed conversion rate in weeks three and four was improved for Treatment 5 compared with Treatment 4 (1.30 v. 1.39 (s.e. 0.06) g/g, P < 0.01). In experiment 3, FA increased (P < 0.05) pig weight at day 14 (8.4 v. 7.7 (s.e. 0.2) kg) and feed intake in weeks one and two (223 v. 251, (s.e. 9) g/day). It is concluded that CF did not improve performance but reducing diet ABC or including FA in the diet did improve performance.
    • Erodibility of hill peat

      Mulqueen, J.; Rodgers, M.; Marren, N.; Healy, Mark G. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The energy necessary to entrain soil in water depends on the soil strength. Once entrained, the settling velocity of the eroded soil in water is of fundamental importance to the processes of sediment transport and deposition. In this paper, stream power theory and transport concepts coupled with the equation of continuity were used to derive a transport-limited peat concentration. The ratio of the log of the actual sediment concentration in surface run-off to the log of the transport-limited sediment concentration was the index of erosion used. The value of this index is a measure of the sensitivity of peat to erosion by sheet flow. Four peats were subjected to a range of overland flow rates under two slopes in a laboratory flume. The peats represented peat farmed in a sustainable manner (Leenane), overgrazed peat (Maam), peat undergoing erosion (Newport) and peat which had undergone weathering following exposure by a landslip (Croagh Patrick). Both in situ and surface damaged slabs were studied. The results indicate that shearing and remoulding of a wet peat surface (e.g., by animal treading) and weathering of exposed drained peat surfaces predispose peat to erosion. Defoliation by overgrazing is considered to be of secondary importance.
    • Do-it-yourself milk recording as a viable alternative to supervised milk recording in Ireland

      Berry, Donagh P.; Burke, M.; O'Keeffe, M.; O'Connor, P. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The objective of the current study was to determine the feasibility of do-it-yourself (DIY) milk recording in commercial Irish dairy herds as well as the accuracy of predicting 24-h milk production and somatic cell count from part-day samples. The data consisted of 3,850 testday records from 1,565 cows across 23 herds in southern Ireland. Observed part-day and 24-h milk yield and composition were in accordance with previously reported observations in Ireland. Accurate prediction of 24-h milk, fat and protein yield was achieved using either AM or PM samples incorporated within prediction equations. Prediction of daily somatic cell count (SCC) was less accurate although the sensitivity and specificity of predicted daily SCC at identifying true daily SCC ≥ 200,000 was high. The accuracy of predicting 24-h fat and protein yield was augmented when two consecutive milk weights, simultaneous with one milk composition, were included in the prediction equation. Minimal effect on accuracy was observed when two milk weights were included in the prediction model for daily SCC. Thus, AM or PM SCC alone are as good, if not better, an indicator of daily SCC than predicted daily SCC using prediction equations. Milking interval defined as individual cowtestday interval measured in minutes fitted the data better than individual cow-testday interval rounded to the nearest half-hour, which was in turn superior to average herdtestday interval and average herd interval. Hence, results from this study suggest DIY milk recording is a viable alternative to supervised milk recording in Ireland.
    • Effects of transporting bulls at different space allowances on physiological, haematological and immunological responses to a 12-h journey by road

      Earley, Bernadette; O'Riordan, Edward G. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effects of space allowance during transportation on physiological, haematological and immunological responses in nine-month old bulls (250 kg) were assessed before and after a 12-h road journey. Following transport, animals transported at a spatial allowance of 1.27 m2 had higher (P ≤0.001) non-esterified fatty acid concentrations than control. The stimulated production of interferon-, in response to concanavalin-A and keyhole limpet haemocyanin, and plasma cortisol were not different at the 0.85 m2 and 1.27 m2 stocking densities. Glucose and albumin concentrations were higher (P ≤0.001) post-transport in all transported animals than control. The percentage lymphocytes was reduced (P ≤0.001) and neutrophil percentage and the number of neutrophils were increased (P ≤0.001) in all transported treatments. There were no changes (P 0.05) in monocyte numbers, monocyte percentage or platelet numbers following transportation. The haematocrit values were higher (P ≤0.001) in the transported treatments while RBC numbers were higher (P ≤0.001) in the animals transported at a spatial allowance of 1.27 m2 than control. Protein, globulin, urea and lactate concentrations, and white blood cell numbers were not changed at any time during the study. The concentration of -hydroxybutyrate was lower (P ≤0.001) in all animals following transport. Plasma haptoglobin concentrations were unchanged following transportation while plasma fibrinogen concentrations were reduced in all transported treatments. There were no differences among treatments in rectal temperature or live weights pre- and post-transport. The results indicate that within the conditions of the study, there was no welfare advantage in transporting bulls at 1.27 m2 versus the standard spatial allowance of 0.85 m2 on a 12-h road journey.
    • Factors affecting body condition score, live weight and reproductive performance in spring-calving suckler cows

      Drennan, Michael J; Berry, Donagh P. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The objective was to identify factors affecting live weight (LW), body condition score (BCS), calving rate and calving interval in spring-calving suckler cows. A total of 925 records on 299 cows from the years 1987 to 1999 were used and the data were analyzed using mixed models and generalised estimating equations. Cows calving early in the year (< day 65 of the year) were significantly heavier at the start of winter, had greater BCS at the subsequent calving but lost most LW in winter. Despite having higher LW gain at pasture, annual LW gain of early-calving cows was lower than that of late-calving cows (> day 90 of the year). Trends in BCS were similar to LW but there was no effect of calving date on annual BCS change. Cows in parity 1, 2, 3 to 7 and >7 had initial LW of 523, 549, 614 and 623 kg, winter LW losses of 61, 52, 65 and 67 kg and LW gains at pasture of 81, 99, 94 and 75 kg, respectively. First parity animals had higher BCS at the start of winter but had greater BCS loss in winter and lower BCS gain at pasture than the other three parity groups. Overall pregnancy rate was 93.6% and was not affected by either previous calving date or cow parity. Mean calving interval was 367 days and was affected by previous calving date but there was no effect of either cow parity or previous calving difficulty. Mean calving interval for cows calving early, mid-season or late were 378, 364 and 353 days, respectively. The results show that good reproduction performance can be achieved in spring-calving suckler cows subjected to low feeding levels during the winter period but grazed on well-managed pasture in summer.
    • Comparison of a Calan gate and a conventional feed barrier system for dairy cows: feed intake and cow behaviour

      Ferris, C.P.; Keady, Tim; Gordon, F.J.; Kilpatrick, D.J. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      There is little published information on comparisons of individual and group feeding systems for dairy cows. Twenty-four dairy cows were used in a three-period incompletely balanced, change-over design study, to examine food intake and feeding behaviour of dairy cows offered their food via group-access electronic Calan gates, or via a conventional feed-barrier system. The food offered was in the form of a complete diet, and comprised grass silage and concentrates (60:40 dry matter (DM) basis). With the conventional feed-barrier system a maximum of eight animals were able to feed at any one time, while the Calan-gate system allowed a maximum of three animals to feed at any one time. Method of offering the ration had no effect on daily DM intake. During the 8-h period after animals were given access to fresh food, the mean number of animals feeding at any one time was 5.4 and 3.0 for the conventional and Calan-gate systems, respectively, while total intake over this period was 11.0 and 9.2 kg DM per cow, respectively. When access to feed was restricted by the use of Calan gates, animals responded by increasing their intake rate. It is concluded that total DM intake was unaffected by the use of a group Calan-gate feeding system as animals modified their feeding behaviour to maintain food intake.
    • The effect of cereal type and feeding frequency on intake, rumen fermentation, digestibility, growth and carcass traits of finishing steers offered a grass silage-based diet

      Drennan, Michael J; McGee, Mark; Moloney, Aidan P (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effect of concentrate cereal type (rolled barley-based v. rolled wheat-based) and concentrate feeding frequency (one 6 kg feed v. two 3 kg feeds per day) on intake, rumen fermentation, diet digestibility and performance of finishing steers offered grass silage to appetite was evaluated over four experiments using a total of 154 animals. Not all four feeding treatments were used in each of the four experiments. The duration of the growth measurement period was 152, 112, 111 and 113 days for experiments 1 to 4, respectively, after which all animals were slaughtered. Dietary dry matter (DM) intake and in vivo digestibility, final live weight, kill-out proportion, carcass weight, carcass conformation score, carcass fat score and daily liveweight and estimated carcass gain were not affected (P > 0.05) by cereal type or feeding frequency. Cereal type or feeding frequency had no effect (P > 0.05) on feed conversion efficiency (FCE) expressed as either live-weight or carcass gain per unit DM intake. Neither mean rumen fluid pH or concentrations of ammonia or L-lactate were influenced by cereal type or feeding frequency. The mean molar proportion of propionate was higher and that of butyrate lower (P < 0.05) with wheat than with barley. Estimated carcass weight gain and FCE to carcass were similar for wheat based and barley-based concentrate as a supplement to grass silage offered either as one feed or two equal feeds daily.
    • The use of near infrared reflectance spectroscopy (NIRS) for prediction of the nutritive value of barley for growing pigs

      McCann, M.E.E.; McCracken, K.J.; Agnew, R.E. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      There is a need in the feed industry for a rapid means of evaluating the nutritive value of feeds and feed ingredients. Chemical analysis provides only basic information and most of the laboratory techniques take too long for this information to be of use in feed formulation at the feed mill. Near infrared reflectance spectroscopy (NIRS) has been proposed as an alternative means of predicting nutritive value. In this study, NIRS was used to predict the digestible energy (DE) concentration and in vitro ileal digestibility of crude protein (CP) and total-tract digestibility of energy of locally produced barley. The calibration and validation statistics were developed using modified partial least squares (MPLS). Derivatisation and scatter correction procedures were carried out to reduce interference from external effects. The correlations between actual and predicted DE values, based on both calibration (R2 0.93) and validation (R2 0.69), were strong with corresponding low standard errors of calibration (SEC) and cross validation (SECV) (SEC 0.128, SECV 0.279). Strong correlations were also observed between predicted and actual in vitro digestibility values for both calibration and validation exercises. It was noted that validation weakened the correlations (R2 0.73 vs. 0.50 for in vitro ileal digestibility of CP and 0.80 vs. 0.68 for in vitro total tract digestibility of energy) and fractionally increased the standard errors (0.016 vs. 0.020 for in vitro ileal digestibility of CP and 0.018 vs. 0.024 for in vitro total tract digestibility of energy). The correlations obtained by cross validation of the lowest SECV equations were not significantly different to those obtained by the scatter correction treatments. The strong relationships and low standard errors obtained between the actual and predicted values indicates that NIRS may be of use in predicting the nutritive value of barley for growing pigs, although more research is required to include larger sample sets.
    • Responses of grain yield, biomass and harvest index and their rates of genetic progress to nitrogen availability in ten winter wheat varieties.

      White, E.M.; Wilson, F.E.A. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      Increased yields in winter wheat cultivars have been found to be largely attributable to improved partitioning of biomass to the grain, i.e., higher harvest index. However, there is a biological upper limit to harvest index and therefore breeders need to exploit increased biomass production as the mechanism by which yields are increased. Evidence for improved biomass was sought in experiments conducted over three years (1994 to 1996), at the Plant Testing Station, Crossnacreevy, near Belfast, with 10 varieties of winter wheat introduced over the period 1977 to 1991. Variation in grain yield was more strongly associated with variation in biomass (an increase of 0.78 t/ha in grain yield at 85% dry matter (DM) per 1t/ha increase in biomass at 100% DM; R2 = 0.71) than in harvest index (an increase of 0.1t/ha at 85% DM per percentage point increase in harvest index; R2 = 0.36). When age (= year of first harvest in UK National List trials) of the varieties was taken into account, yield (0.037 t ha−y−; R2 = 0.42) and biomass (0.034 t ha−y−; R2 = 0.31), but not harvest index (0.34%/year; R2 = 0.001), increased as year increased. Genetic gain in yield was smaller without fertiliser N (0.021 t ha−y−; R2 = 0.21) and at 40 kg ha N (0.025 t ha−y−; R2 =0.25) than at 215–250 kg/ha N (0.065 t ha−y−; R2 = 0.39). Theoretically, if the maximum biomass (18.60 t/ha for Rialto), could have been combined with the maximum harvest index (55.3%) in Riband, yield would potentially have been increased by 2.5 t/ha compared with yields for either variety.
    • Monitoring of nitrogen leaching on a dairy farm during four drainage seasons

      Ryan, Michael; Brophy, C.; Connolly, J.; McNamara, K.; Carton, Owen T. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effect of four commonly used dairy farm management systems (treatments), on nitrogen leaching to 1 m was studied over a 4-year period from October 2001 to April 2005. The treatments were (i) grazed plots receiving dirty water, (ii) 2-cut silage plots receiving slurry, (iii) grazed plots and (iv) 1-cut silage plots receiving slurry. All plots had fertiliser N applied; the soil was free-draining overlying fissured limestone. Mean 4-year N input (kg/ha) was 319 and mean annual stocking density was ~2.38 LU/ha. The annual average and weekly NO3-N and NH4-N concentrations in drainage water were analysed for all years, using a repeated measures analysis. For the annual NO3-N data, there was an interaction between treatment and year (P < 0.001). There were significant differences (P < 0.05) in NO3-N concentrations between the treatments in all years except the third. For the NH4-N data there was no interaction between treatment and year or main effect of treatment but there were differences between years (P < 0.01). Mean weekly concentrations were analysed separately for each year. For NO3-N, in all years but the third, there was an interaction between treatment and week (P < 0.001); this occurred with NH4-N, in all 4 years. Dirty water was significantly higher than grazed-fertiliser only and 1-cut silage in NO3-N concentrations in 2001–02; in 2002–03, dirty water and 2-cut silage were significantly higher than the other treatments; while in 2004–05, dirty water and grazed-fertiliser only were significantly higher than the other two treatments. The overall 4-year mean NO3-N and NH4-N concentrations were 8.2 and 0.297 mg/L, respectively.
    • An evaluation of seed-pellet insecticides in a precision drilled crop of sugar beet

      Kennedy, T.F.; Connery, J. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The control of soil pests of sugar beet by means of seed-pellet insecticides was investigated on each of two farms in Co. Wexford from 2000 to 2002. The farms on which trials were conducted differed each season. A number of seed-pellet insecticides were compared with the standard methiocarb seed treatment, methiocarb supplemented with the in-furrow applied granule insecticide carbo furan-isofenphos and with an untreated control. Imidacloprid, Montur and thiamethoxam significantly reduced onychiurid numbers around seedlings compared with the untreated control and significantly reduced pest damage to seedlings compared with the standard methiocarb treatment. Imidacloprid gave best control of pest biting of seedlings and was as effective as the in-furrow incorporated granule insecticide in preventing pest damage and plant mortality at sites having moderate onychiurid infestations. Montur, while less effective than imidacloprid in controlling pest bites on seedling roots, gave consistently good plant establishment. Thiamethoxam was less effective than imidacloprid in some trials at reducing plant damage and mortality. The retardation of seedling growth and establishment recorded for insecticidepropamocarb combinations relative to insecticide-hymexazol combinations in some field and glasshouse trials could be overcome by replacing propamocarb with hymexazol.
    • The microbiological and chemical composition of baled and precision-chop silages on a sample of farms in County Meath

      McEniry, Joseph; O'Kiely, Padraig; Clipson, N.W.J; Forristal, P.D.; Doyle, E.M.; Teagasc Walsh Fellowship Programme; (Teagasc, Oak Park, Carlow, Ireland, 2006)
      Baled and precision-chop silages were examined on a sample of farms in the Irish midlands to determine microbiological and chemical composition at feedout. Silage making practices and chemical composition were similar to those in national surveys. Wilting was an integral part of baled silage production and was reflected in a more restricted fermentation (higher pH and water-soluble carbohydrates, with lower fermentation acids and buffering capacity) compared to precision-chop silage. Yeast numbers were higher in baled silage, suggesting a more aerobic environment within the bale. Although the fermentation appeared similar in the outer and inner horizons of baled silage, yeast, lactic acid bacteria and Enterobacteria numbers were higher in the outer horizon suggesting less exacting anaerobiosis adjacent to the surface of the bale.
    • Effects of pre-transport fasting on the physiological responses of young cattle to 8-hour road transport

      Earley, Bernadette; Fisher, A.D.; O'Riordan, Edward G. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The effects of fasting animals for 8 h prior to an 8-h road journey and their ability to cope with the stress of transport were investigated. The treatments were: 1) fasted and then transported (n=20); 2) non-fasted and transported (n=18); 3) non-fasted at grass (n=18); 4) fasted then fasted (n=18), and 5) non-fasted then fasted (n=18). There was no significant difference in rectal body temperature, pre- or post-transport, or live weight among treatments on days 0 (pre-transport), 1, 4 or 10 (post-transport). The ambient relative humidity and temperature of the outside environment ranged from 82.8 to 99.8% and 9.9 to 14.5 oC, respectively. Holstein × Friesian bulls (230 kg) undergoing an 8-h transportation at stocking densities of 0.82 m2/animal showed physiological and haematological responses that were within normal referenced ranges. Animals that were fasted for 8 h and transported lost 9.4% of live weight while non-fasted transported animals lost 7.2%. The control non-fasted animals remaining at grass gained 2% of live weight. Animals that were fasted continuously but not transported and the initially non-fasted control animals that were subsequently fasted for 9 h lost 6.1% and 6.2% of live weight, respectively. There was no significant change in concentrations of globulin, glucose, urea, haemoglobin or fibrinogen, or in haematocrit percentage before or after transport. Transport reduced lymphocyte percentage (P < 0.001) and increased neutrophil percentage (P < 0.001) in the fasted and non-fasted animals. Following transport, protein concentration was greater (P ≤0.001) in the fasted and transported animals than in the non-fasted animals at grass and haptoglobin concentrations were higher (P ≤0.001) in the fasted plus transported animals than the controls at grass. In conclusion, from the physiological and haematological measurements, an 8-h journey time, even without access to feed for 8 h prior to transport did not appear to impact negatively on animal welfare.
    • Changes in yield and composition of barley, wheat and triticale grains harvested during advancing stages of ripening

      Stacey, P.; O'Kiely, Padraig; Hackett, Richard; Rice, B.; O'Mara, Frank P.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2006)
      This study involved an evaluation of the changes in grain yield, nutritive value, ensilability and harvesting losses of intensively managed winter cereals harvested during the advancing stages of ripening. Five cereal crops (barley cv. Regina and wheat cv. Madrigal in 2001; barley cv. Regina, wheat cv. Falstaff and triticale cv. Fidelio in 2002) were assessed. Twenty plots per crop were arranged in a randomised complete block design, with five times of harvest (four for barley in 2002) and four replicate blocks per harvest. Dry matter (DM) yields changed relatively little between harvest dates, but fresh yields declined (P < 0.001) over time due to the moisture loss associated with ripening. Time-course changes in indices of nutritive value, such as concentrations of crude protein, starch and ash, and organic matter digestibility, were relatively small and did not follow a consistent pattern. Ensilability indices, such as DM and watersoluble carbohydrate concentrations and buffering capacity, indicated that satisfactory fermentations were likely if such crops were ensiled; buffering capacity, generally declining with advancing maturity. Harvesting losses were not clearly related to growth stage at harvest. It is concluded that winter cereal grain (barley, wheat and triticale) DM yields and quality were relatively constant as ripening progressed from DM concentrations of around 550 to >800 g/kg.
    • Effect of variety, endosperm hardness, the 1B/1R translocation and enzyme addition on the nutritive value of wheat for growing pigs

      McCann, M.E.E.; McEvoy, J.D.G.; McCracken, K.J.; Simmins, P.H. (Teagasc, Oak Park, Carlow, Ireland, 2006)
      It has been widely recognised that wheat chemical composition and nutritive value can vary as a result of genotypic differences, but there is a lack of information on wheat grown in Northern Ireland. Furthermore, there have been conflicting reports regarding the effect of endosperm hardness, the 1B/1R translocation and enzyme addition on the nutritive value of wheat for growing pigs. The effects of wheat variety, endosperm hardness, the presence of the 1B/1R translocation and enzyme addition were examined in four experiments involving a total of 326 Large White Landrace pigs. Performance traits of individually housed pigs were measured in Experiments 1, 3 and 4 and apparent in vivo digestibility coefficients were determined at the total tract and ileal level from post-valve-T-caecum cannulated pigs in Experiment 2. The results obtained for the analysis of the chemical composition of the eight varieties were mainly within reported limits. However, there was a wide range of crude protein concentrations (97.8 to 138.7g/kg dry matter) suggesting varietal differences. There was no effect of endosperm hardness or the 1B/1R translocation on chemical composition. In contrast to other research reports, there were no significant differences in pig performance as a result of either variety, endosperm hardness or the presence of the 1B/1R translocation. However, there were significant variety effects on apparent total-tract digestibility coefficients. Enzyme supplementation had no significant effect on pig performance, despite the fact that the basal diet did not have a high nutrient specification.
    • Modelling fat and protein concentration curves for Irish dairy cows

      Quinn, N.; Killen, L.; Buckley, Frank (Teagasc, Oak Park, Carlow, Ireland, 2006)
      The objective of this study was to acquire a well-fitting, single-equation model that would represent the fat and protein concentration curves of milk from Irish dairy cows. The dataset consisted of 16,086 records from both spring and autumn calving cows from both experimental and commercial herds. Many models cited in the literature to represent milk yield were examined for their suitability to model constituent curves. Models were tested for goodness-of-fit, adherence to the assumptions of regression analysis, and their ability to predict total fat and protein concentration for an entire lactation. Wilmink’s model best satisfied these criteria. It had the best Mean Square Prediction Error (goodness-of-fit) value, it satisfied the assumptions of regression analysis (multicollinearity, heteroskedasticity, autocorrelation and normality of distribution), and it predicted the actual concentration of the constituents to within 0.01 percentage point.