• Animal performance and economic implications of alternative production systems for dairy bulls slaughtered at 15 months of age

      Murphy, B.M.; Crosson, Paul; Kelly, Alan K; Prendiville, Robert; Department of Agriculture, Food and the Marine, Ireland; 11/SF/322 (Teagasc (Agriculture and Food Development Authority), Ireland, 2017-10-26)
      The objectives of this experiment were to investigate (i) the influence of varying levels of concentrate supplementation during the grazing season, (ii) alternative finishing strategies for dairy bulls slaughtered at 15 mo of age and (iii) economic implications of these management strategies. Bulls were assigned to a 2 (level of concentrate supplementation during the grazing season: 1 kg [LA] and 2 kg [HA] dry matter [DM]/head daily) × 2 (finishing strategies: concentrates ad libitum group [AL] or grass silage ad libitum plus 5 kg DM of concentrates/head daily group [SC]) factorial arrangement of treatments. Average daily gain (ADG) during the grazing season was greater (P < 0.01) for HA than for LA. Consequently, HA bulls were 16 kg heavier at housing: 214 and 230 kg, respectively (P < 0.05). During the finishing period, ADG tended (P = 0.09) to be greater for LA than for HA. Carcass weight tended (P = 0.08) to be greater for HA than for LA. Fat score was greater for HA. Live weight at slaughter (P < 0.001) and carcass weight (P < 0.001) were 41 and 23 kg greater for AL than for SC, respectively. Conformation (P < 0.05) and fat score (P < 0.05) were greater for AL than for SC. The Grange Dairy Beef Systems Model simulated whole-farm system effects of the production systems. Net margin/head was greater for LA than for HA and greater for SC than for AL. Sensitivity analysis of finishing concentrate price, calf purchase price and beef price showed no re-ranking of the systems on a net margin basis. Although greater animal performance was observed from the higher plane of nutrition, overall profitability was lower.
    • The application of transcriptomic data in the authentication of beef derived from contrasting production systems

      Sweeney, Torres; Lejeune, Alexandre; Moloney, Aidan; Monahan, Frank J; Gettigan, Paul M; Downey, Gerard; Park, Stephen D. E.; Ryan, Marion T; Department of Agriculture, Food and the Marine (Biomed Central, 2016-09-21)
      Background Differences between cattle production systems can influence the nutritional and sensory characteristics of beef, in particular its fatty acid (FA) composition. As beef products derived from pasture-based systems can demand a higher premium from consumers, there is a need to understand the biological characteristics of pasture produced meat and subsequently to develop methods of authentication for these products. Here, we describe an approach to authentication that focuses on differences in the transcriptomic profile of muscle from animals finished in different systems of production of practical relevance to the Irish beef industry. The objectives of this study were to identify a panel of differentially expressed (DE) genes/networks in the muscle of cattle raised outdoors on pasture compared to animals raised indoors on a concentrate based diet and to subsequently identify an optimum panel which can classify the meat based on a production system. Results A comparison of the muscle transcriptome of outdoor/pasture-fed and Indoor/concentrate-fed cattle resulted in the identification of 26 DE genes. Functional analysis of these genes identified two significant networks (1: Energy Production, Lipid Metabolism, Small Molecule Biochemistry; and 2: Lipid Metabolism, Molecular Transport, Small Molecule Biochemistry), both of which are involved in FA metabolism. The expression of selected up-regulated genes in the outdoor/pasture-fed animals correlated positively with the total n-3 FA content of the muscle. The pathway and network analysis of the DE genes indicate that peroxisome proliferator-activated receptor (PPAR) and FYN/AMPK could be implicit in the regulation of these alterations to the lipid profile. In terms of authentication, the expression profile of three DE genes (ALAD, EIF4EBP1 and NPNT) could almost completely separate the samples based on production system (95 % authentication for animals on pasture-based and 100 % for animals on concentrate- based diet) in this context. Conclusions The majority of DE genes between muscle of the outdoor/pasture-fed and concentrate-fed cattle were related to lipid metabolism and in particular β-oxidation. In this experiment the combined expression profiles of ALAD, EIF4EBP1 and NPNT were optimal in classifying the muscle transcriptome based on production system. Given the overall lack of comparable studies and variable concordance with those that do exist, the use of transcriptomic data in authenticating production systems requires more exploration across a range of contexts and breeds.
    • Comparison of pasture and concentrate finishing of Holstein Friesian, Aberdeen Angus × Holstein Friesian and Belgian Blue × Holstein Friesian steers

      Keane, Michael G.; Moloney, Aidan P (Teagasc, Oak Park, Carlow, Ireland, 2010)
      Crossbreeding Holstein Friesian dairy cows with both early and late maturing beef breed bulls is common in Ireland. This study concerned the comparison of spring-born Holstein Friesian (HF), Aberdeen Angus × Holstein Friesian (AA) and Belgian Blue × Holstein Friesian (BB) steers slaughtered directly off pasture in the autumn or following a period of concentrate finishing indoors. Male calves (18 per breed type) were reared together until August of their second year when they were assigned to a 3 (breed type) × 3 (finishing strategy) factorial experiment. The three finishing strategies were (i) pasture only for 94 days to slaughter (PE), (ii) concentrate ad libitum indoors for 94 days to slaughter (CE), and (iii) pasture only for 94 days followed by concentrate ad libitum indoors for 98 days to slaughter (PC). For HF, AA, and BB, mean carcass weight, carcass conformation score and carcass fat score values were 275, 284 and 301 (s.e. 5.1) kg, 1.75, 2.42 and 2.89 (s.e. 0.11), and 2.48, 2.89 and 2.17 (s.e. 0.11), respectively. Pasture alone supported live-weight and carcass-weight gains of approximately 800 g/day and 400 g/day, respectively. Live-weight and carcass-weight gains on concentrate ad libitum were approximately 1400 and 870 g/day, respectively. For PE, CE and PC, mean carcass weight, carcass conformation score and carcass fat score values were 244, 287 and 329 (s.e. 5.1) kg, 1.81, 2.56 and 2.69 (s.e. 0.11), and 1.83, 2.71 and 3.01 (s.e. 0.11), respectively. It is concluded that none of the breed types reached an acceptable carcass weight on PE and only HF had acceptable carcass finish. All breed types were acceptably finished on both concentrate finishing strategies.
    • Effect of feed allowance at pasture on the lying behaviour of dairy cows

      O’Driscoll, Keelin; Lewis, Eva; Kennedy, Emer (Elsevier, 2019-02-10)
      In temperate climates where cows are primarily managed at pasture shortages of grass could result in nutritional deficits for the cow and may have a variety of behavioural consequences. Lying behaviour is one of the most researched aspects of dairy cow behaviour, and can provide insights into cow welfare and physiological state. This study investigated the effect of daily herbage allowance (DHA) on the lying behaviour of dairy cow during early lactation. Ninety-six cows were randomly assigned to one of eight treatments in a 2 × 4 factorial design; experimental duration (2 week (2 W) or 6 week (6 W)), and nutritional levels (DHA) (60%, 80%, 100% or 120% of intake capacity). Cows were assigned to treatment at 28 ± 8.4 days in milk, and lying behaviour of cows in the 6 W treatments recorded using modified voltage data loggers on 4 occasions; the week prior to the start of the experiment, during week 3 (MID), and week 6 (LATE), and 7 weeks after the study concluded (POST), when the cows were all returned to a feed allowance of 100% intake capacity. Although there was an effect of treatment on daily lying time (P < 0.01), with the 60% cows spending less time lying than the 120% (P < 0.01), cows in all treatments spent at least 9 h lying per day throughout the experiment. Daily lying time increased as the grazing season progressed (P < 0.001). Feed allowance affected both lying bout duration (P < 0.01) and number (P < 0.05), with cows on the highest feed allowance having the highest values for both. There was an effect of feed allowance on the time that cows first lay down after both morning and afternoon milking (P < 0.001), with a similar pattern for both times; the lower the feed allowance, the longer it took. During the POST period, this pattern was no longer evident in the afternoon, but still present in the morning. None of the treatments imposed resulted in daily lying times lower than those reported in other studies at pasture. However, the significant differences in patterns of lying during the day could be reflective of satiety level; the patterns of lying in cows with a low feed allowance compared to those with an allowance aligned with intake capacity are in agreement with previous research. Herd level recording of lying behaviour, relative to time since milking and/or fresh feed allocation, has potential for use as an animal welfare indicator for cows at pasture.
    • Effect of feed allowance at pasture on the lying behaviour of dairy cows

      O'Driscoll, Keelin; Lewis, Eva; Kennedy, Emer (Elsevier, 2019-02-10)
      In temperate climates where cows are primarily managed at pasture shortages of grass could result in nutritional deficits for the cow and may have a variety of behavioural consequences. Lying behaviour is one of the most researched aspects of dairy cow behaviour, and can provide insights into cow welfare and physiological state. This study investigated the effect of daily herbage allowance (DHA) on the lying behaviour of dairy cow during early lactation. Ninety-six cows were randomly assigned to one of eight treatments in a 2 × 4 factorial design; experimental duration (2 week (2 W) or 6 week (6 W)), and nutritional levels (DHA) (60%, 80%, 100% or 120% of intake capacity). Cows were assigned to treatment at 28 ± 8.4 days in milk, and lying behaviour of cows in the 6 W treatments recorded using modified voltage data loggers on 4 occasions; the week prior to the start of the experiment, during week 3 (MID), and week 6 (LATE), and 7 weeks after the study concluded (POST), when the cows were all returned to a feed allowance of 100% intake capacity. Although there was an effect of treatment on daily lying time (P < 0.01), with the 60% cows spending less time lying than the 120% (P < 0.01), cows in all treatments spent at least 9 h lying per day throughout the experiment. Daily lying time increased as the grazing season progressed (P < 0.001). Feed allowance affected both lying bout duration (P < 0.01) and number (P < 0.05), with cows on the highest feed allowance having the highest values for both. There was an effect of feed allowance on the time that cows first lay down after both morning and afternoon milking (P < 0.001), with a similar pattern for both times; the lower the feed allowance, the longer it took. During the POST period, this pattern was no longer evident in the afternoon, but still present in the morning. None of the treatments imposed resulted in daily lying times lower than those reported in other studies at pasture. However, the significant differences in patterns of lying during the day could be reflective of satiety level; the patterns of lying in cows with a low feed allowance compared to those with an allowance aligned with intake capacity are in agreement with previous research. Herd level recording of lying behaviour, relative to time since milking and/or fresh feed allocation, has potential for use as an animal welfare indicator for cows at pasture.
    • A national methodology to quantify the diet of grazing dairy cows

      OBrien, Donal; Moran, Brian; Shalloo, Laurence (Elsevier, 2018-07-04)
      The unique rumen of dairy cows allows them to digest fibrous forages and feedstuffs. Surprisingly, to date few attempts have been made to develop national methods to gain an understanding on the make-up of a dairy cow's diet, despite the importance of milk production. Consumer interest is growing in purchasing milk based on the composition of the cows' diet and the time they spend grazing. The goal of this research was to develop such a methodology using the national farm survey of Ireland as a data source. The analysis was completed for a 3-yr period from 2013 to 2015 on a nationally representative sample of 275 to 318 dairy farms. Trained auditors carried out economic surveys on farms 3 to 4 times per annum. The auditors collected important additional information necessary to estimate the diet of cows including the length of the grazing season, monthly concentrate feeding, type of forage(s) conserved, and milk production. Annual cow intakes were calculated to meet net energy requirements for production, maintenance, activity, pregnancy, growth, and live weight change using survey data and published literature. Our analysis showed that the average annual cow feed intake on a fresh matter basis ranged from 22.7 t in 2013 to 24.8 t in 2015 and from 4.8 to 5 t on a dry matter basis for the same period. Forage, particularly pasture, was the largest component of the Irish cow diet, typically accounting for 96% of the diet on a fresh matter basis and 82% of dry matter intake over the 3 yr. Within the cows' forage diet, grazed pasture was the dominant component and on average contributed 74 to 77% to the average annual cow fresh matter diet over the period. The proportion of pasture in the annual cow diet as fed was also identified as a good indicator of the time cows spend grazing (e.g., coefficient of determination = 0.85). Monthly, forage was typically the main component of the cow diet, but the average contribution of concentrate was substantial for the early spring months of January and February (30 to 35% of dry matter intake). Grazed pasture was the dominant source of forage from March to October and usually contributed 95 to 97% of the diet as fed in the summer period. Overall, the national farm survey from 2013 to 2015 shows that Irish dairy farms are very reliant on forage, particularly pasture, regardless of whether it is reported on a dry matter basis or as fed. There is potential to replicate this methodology in any regions or nations where representative farm surveys are conducted.
    • Prevalence of, and risk factors associated with, perinatal calf mortality in pasture-based Holstein-Friesian cows

      Mee, John F; Berry, Donagh; Cromie, A. R. (Cambridge University Press, 2008-04)
      Recent publications indicate that the prevalence of perinatal mortality has increased in some dairy industries and an increased proportion of this loss is not associated with the traditional risk factors for perinatal mortality. The objectives of this study were to establish the prevalence of perinatal mortality (calf death within 24 h of calving) in Irish dairy herds and to determine the current significance of putative risk factors in pasture-based management systems. A total of 182 026 records of full-term calvings from Holstein-Friesian dams served by artificial insemination (AI) sires of seven breeds in herds of 20 calvings or more per year were available from the Irish national breeding database over 4 years (2002 to 2005). The prevalence of perinatal mortality was 4.29% (7.7% in primiparae and 3.5% in pluriparae). The likelihood of perinatal mortality increased between 2002 and 2005 and was greatest in June and in winter. There was an interaction (P < 0.001) between the effect of calving assistance and parity with the effect of dystocia on perinatal mortality being greater in primiparae. The odds of perinatal mortality were greater in male (OR = 1.12; P < 0.001) and in twin calves (OR = 5.70-13.36; P < 0.001) and in dams that had perinatal mortality at the previous calving (OR = 4.21; P < 0.001). The logit of the probability of perinatal mortality increased by 0.099 per unit increase in sire predicted transmitting ability (PTA) for direct perinatal mortality. The probability of perinatal mortality increased at an increasing rate in primiparae as animals calved at a younger age relative to the median age at first calving. The only herd-level factor examined, herd size did not affect the odds of perinatal mortality. These data indicate that the prevalence of perinatal mortality in this cattle population is similar to that in other pasture-based dairy systems worldwide. The putative exposures and attributes traditionally associated with perinatal mortality were associated with perinatal mortality in this pasture-based dairy cow population. The practical implication of these results is that as many of the significant risk factors are largely not under management control (year of calving, month of calving, twin calving, primiparity, previous perinatal mortality and foetal gender), herd owners must focus on the significant determinants under their control (age at first calving, sire genetic merit for direct perinatal mortality and both the extent of calving supervision and the degree of assistance), in order to reduce the prevalence of perinatal mortality and improve perinatal welfare.