Browsing by Author "Gordon, Alan W."

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    Consumer assessment, in Ireland and the United Kingdom, of the impact of the method of suspension of carcasses from dairy-origin bulls and steers, on the sensory characteristics of the longissimus muscle
    (Compuscript Ltd. on behalf of Teagasc, 2023-06-17) Moloney, A.P.; Chong, F.S.; Hagan, T.D.J.; Gordon, Alan W.; Methven, L.; O’Sullivan, M.G.; Farmer, Linda; Food Quality
    The objective was to compare the assessment of beef produced in Ireland from a 19-month bull or a 24-month steer dairy beef production system by consumers in Ireland (Cork) and the United Kingdom (Belfast and Reading). Carcass sides were suspended by the Achilles tendon or by the pelvic bone and 21-d aged longissimus muscle assessed using Meat Standards Australia protocols. Carcass weight and classification were similar for bulls and steers. Consumers in Belfast and Cork rated aroma liking, tenderness, juiciness, overall liking and the composite meat quality score (MQ4) similarly, but lower (P < 0.05) than consumers in Reading. Consumers in Belfast and Cork rated flavour liking similarly as did consumers in Cork and Reading, but consumers in Reading rated flavour liking higher (P < 0.05) than consumers in Belfast. Muscle from steers had higher scores for aroma liking, flavour liking, overall liking and MQ4 scores than bulls (P < 0.05). On average, pelvic suspension increased (P < 0.05) the scores for aroma liking and flavour liking compared with conventional suspension but increased (P < 0.05) tenderness, juiciness, overall liking and MQ4 scores only in bulls. Consumers in Reading rated striploin from the traditional Achilles tendon-suspended steers similarly to striploin from pelvic-suspended bulls (MQ4 score of 71.8 and 68.2, respectively). Beef from the latter system could replace the traditional steer beef in this market, thereby benefiting the beef producer and the environment.
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    The Effect of Frequency of Fresh Pasture Allocation on Pasture Utilisation and the Performance of High Yielding Dairy Cows
    (MDPI, 2020-11-21) Pollock, Jessica G.; Gordon, Alan W.; Huson, Kathryn M.; McConnell, Deborah
    Pasture allocation frequency (PAF) can influence pasture availability and grazing behaviour, which subsequently may impact on animal performance. Limited research to-date has investigated grazing management methods to improve the performance of high production dairy cows whilst also achieving high grass utilisation rates. This study evaluated the e ect of three di erent PAF’s (12, 24 and 36 h) on pasture utilisation, the performance of high yielding dairy cows and the interaction with parity. The experiment included two 60-day periods, 90 spring calving dairy cows (27 primiparous animals) in period one and 87 (24 primiparous animals) in period two. The average pre-grazing sward height (11.4 cm) was similar for all treatments in both periods. In period one, pasture utilisation rate was significantly higher (8%) in the 36 h compared to the 12 h treatment. In period two, milk energy output was significantly greater for primiparous animals in the 36 h treatment relative to the other treatments.
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    Revisiting the Relationships between Fat-to-Protein Ratio in Milk and Energy Balance in Dairy Cows of Different Parities, and at Different Stages of Lactation
    (MDPI, 2021-11-14) Cabezas-Garcia, Edward; Gordon, Alan W.; Mulligan, Finbar J.; Ferris, Conrad P.
    Simple Summary Data from 840 Holstein-Friesian cows (1321 lactations) were used to evaluate trends in fat-to-protein ratios in milk (FPR), and the use of FPR as an indicator of energy balance (EB). The fat-to-protein ratio was negatively related to EB, and this relationship became more negative with increased parity. Regression slopes describing linear relationships between FPR and EB differed over time, although trends were inconsistent. Similarly, ‘High’ FPR scores in milk (≥1.5) were consistently associated with a greater negative energy balance, milk yields, body weight loss, and plasma non-esterified fatty acid concentrations; however, their relationships with dry matter intake did not follow a clear trend. Although FPR can provide an indication of EB at a herd level, this analysis suggests that FPR cannot accurately predict the EB of individual cows. Abstract A statistical re-assessment of aggregated individual cow data was conducted to examine trends in fat-to-protein ratio in milk (FPR), and relationships between FPR and energy balance (EB, MJ of ME/day) in Holstein-Friesian dairy cows of different parities, and at different stages of lactation. The data were collected from 27 long-term production trials conducted between 1996 and 2016 at the Agri-Food and Biosciences Institute (AFBI) in Hillsborough, Northern Ireland. In total, 1321 lactations (1 to 20 weeks in milk; WIM), derived from 840 individual cows fed mainly grass silage-based diets, were included in the analysis. The energy balance was calculated daily and then averaged weekly for statistical analyses. Data were further split in 4 wk. intervals, namely, 1–4, 5–8, 9–12, 13–16, and 17–20 WIM, and both partial correlations and linear regressions (mixed models) established between the mean FPR and EB during these periods. Three FPR score categories (‘Low’ FPR, <1.0; ‘Normal’ FPR, 1.0–1.5; ‘High’ FPR, >1.5) were adopted and the performance and EB indicators within each category were compared. As expected, multiparous cows experienced a greater negative EB compared to primiparous cows, due to their higher milk production relative to DMI. Relatively minor differences in milk fat and protein content resulted in large differences in FPR curves. Second lactation cows displayed the lowest weekly FPR, and this trend was aligned with smaller BW losses and lower concentrations of non-esterified fatty acids (NEFA) until at least 8 WIM. Partial correlations between FPR and EB were negative, and ‘greatest’ in early lactation (1–4 WIM; r = −0.38 on average), and gradually decreased as lactation progressed across all parities (17–20 WIM; r = −0.14 on average). With increasing parity, daily EB values tended to become more negative per unit of FPR. In primiparous cows, regression slopes between FPR and EB differed between 1–4 and 5–8 WIM (−54.6 vs. −47.5 MJ of ME/day), while differences in second lactation cows tended towards significance (−57.2 vs. −64.4 MJ of ME/day). Irrespective of the lactation number, after 9–12 WIM, there was a consistent trend for the slope of the linear relationships between FPR and EB to decrease as lactation progressed, with this likely reflecting the decreasing milk nutrient demands of the growing calf. The incidence of ‘High’ FPR scores was greatest during 1–4 WIM, and decreased as lactation progressed. ‘High’ FPR scores were associated with increased energy-corrected milk (ECM) yields across all parities and stages of lactation, and with smaller BW gains and increasing concentrations (log transformed) of blood metabolites (non-esterified fatty acid, NEFA; beta-hydroxybutyrate, BHB) until 8 WIM. Results from the present study highlight the strong relationships between FPR in milk, physiological changes, and EB profiles during early lactation. However, while FPR can provide an indication of EB at a herd level, the large cow-to-cow variation indicates that FPR cannot be used as a robust indicator of EB at an individual cow level.
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    Supplementation strategies for lactating dairy cows offered very high quality grass silages: Starch-based or fibre-based concentrates offered with or without straw
    (Elsevier, 2020-02-15) Craig, Aimee-Louise; Gordon, Alan W.; Stewart, Sharon; Ferris, Conrad P.
    A three-period change-over design study using 24 mid-lactation multiparous Holstein-Friesian dairy cows, examined supplementation strategies for a high quality grass silage (dry matter (DM), 418 g/kg; crude protein (CP), 170 g/kg DM; metabolisable energy (ME), 12.1 MJ/kg DM). Four treatments, in a 2 × 2 factorial arrangement, compared concentrate type (High-starch or High-fibre) and straw inclusion (Straw or No-straw). Concentrates had a starch and neutral detergent fibre content of 373 and 258 g/kg DM, respectively (Highstarch), and 237 and 339 g/kg DM, respectively (High-fibre). In the No-straw treatments, silage and concentrates were offered as a total mixed ration in a 57:43 DM ratio. In the Straw treatments, chopped straw was added at 4% of total DM, replacing part of the silage component of the diet. Following this study, the effect of diet on nutrient utilisation efficiency was examined using four cows/treatment. There were no interactions between concentrate type and straw inclusion for any cow performance or digestibility parameters. Silage dry matter intake (DMI) and total DMI were reduced with the High-fibre concentrate (P = 0.001 and P = 0.006, respectively) and straw inclusion (P < 0.001 and P = 0.014, respectively). Neither concentrate type nor straw inclusion had a significant effect on milk yield or milk fat content. The High-starch concentrate increased milk protein content (P < 0.001), while straw inclusion decreased milk protein content (P = 0.036). Treatment had no effect on cow body weight, condition score, faecal scores, digestibility coefficients or nitrogen and energy utilisation efficiency. In conclusion, supplementing a high quality grass silage with a carefully formulated ‘high starch’ concentrate improved DMI and milk protein content with no adverse effects on cow performance. Straw inclusion in the diet had no beneficial effects on DMI, milk production or nutrient utilisation efficiency.
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    The Impact on Cow Performance and Feed Efficiency When Individual Cow Milk Composition and Energy Intake Are Accounted for When Allocating Concentrates
    (MDPI, 2023-07-03) Craig, Aimee-Louise; Gordon, Alan W.; Ferris, Conrad
    The objective of this three-treatment, 12-week study (involving 69 dairy cows) was to test three methods of concentrate allocation on milk production efficiency. All treatments were offered a basal mixed ration of grass silage and concentrates, with additional concentrates offered to individual cows based on either milk yield alone (Control), milk energy output (Precision 1) or energy intake and milk energy output (Precision 2). Concentrate requirements were calculated and adjusted weekly. Control cows had lower concentrate dry matter intake (DMI; p = 0.040) and milk protein content (p = 0.003) but yield of milk and energy-corrected milk (ECM), energy balance, bodyweight and condition score were unaffected by treatment. Efficiency measures such as ECM/DMI and ECM/metabolizable energy intake were also unaffected by treatment. Less concentrates were used per kg ECM yield in the Control compared to the Precision treatments (p < 0.001). In conclusion, accounting for individual cow milk composition or milk composition combined with individual cow energy intake did not improve production efficiency compared to an approach based on individual cow milk yield only.