• Adding value to cull cow beef

      O'Donovan, Michael; Minchin, William; Buckley, Frank; Kenny, David; Shalloo, Laurence (Teagasc, 2009-08-01)
      This project addressed the prospects of increasing the value of cull cow beef and examined the potential of a number of different management and dietary strategies. In Ireland, the national cow herd contributes 350,000 animals to total beef production annually, which represents 22% of all cattle slaughtered (DAF, 2007). A dominant feature of beef production in Ireland is the disposal of cows from the dairy and beef industries, the time of year at which culling occurs influences the number of cows available for slaughter. Suitability of a cow for slaughter is generally not a consideration for dairy or beef farmers.
    • AI For Sheep Using Frozen-thawed Semen.

      Donovan, A.; Hanrahan, J.P.; Lally, T.; Boland, M.P.; Byrne, G.P.; Duffy, P.; Lonergan, P.; O'Neill, D.J. (Teagasc, 2001-01-01)
      International experience has been that cervical insemination of sheep with frozen-thawed semen usually yields unacceptably low pregnancy rates (10 to 30%). An exceptional case has been Norway where non-return rates in on-farm usage are around 60%. The objective of the work described in this report was to develop an AI procedure for Irish conditions, based initially on Norwegian protocols, using semen from individual rams. Such a procedure would greatly facilitate and enhance genetic improvement programmes for sheep. The work undertaken had two separate aspects:- (i) studies on semen, including processing and freezing methods, laboratory evaluation of semen quality post thawing and the relationship of in vitro evaluation to fertilisation rate in vivo (ii) studies on pregnancy rate following AI in relation to issues such as ram breed effects, effects of synchronisation, operator differences and the role of ewe breed inducing the timing of ovulation and various physical and physiological assessments of the cervix at AI. The main results in relation to semen studies were that, while a range of differential staining procedures could be used to objectively evaluate semen with respect to proportion of live speramatozoa and the integrity of sperm cells after thawing, these results were not useful as indicators of fertilisation capacity in vivo. The in vitro fertilisation (IVF) of sheep oocytes recovered from abattoir material gave promising results as a method for evaluating the fertilisation capacity of frozen-thawed semen. The technique requires further validation.
    • Alternative Enterprises: Economic Performance and Viability.

      Connolly, L. (Teagasc, 1999-11-01)
      The economic environment for Irish farming has changed dramatically over the last two decades. The reform of the Common Agricultural Policy with the introduction of quotas on the main farm enterprises in the 1980’s, forced farmers to consider diversifying into new or “alternative” uses for their land, buildings and other resources. The main objectives of this study were to identify the factors affecting the profitability and expansion in the main alternative livestock enterprises and also in rural tourism. Investment costs, returns on investment and market prospects for these new enterprises were investigated. The main livestock enterprises considered were deer, sport horses, dairy goats and free range poultry.
    • Animal Transport: Developing optimum animal handling procedures and effective transport strategies in the food production chain to improve animal welfare and food quality.

      Earley, Bernadette; Murray, Margaret; Prendiville, Daniel J. (Teagasc, 2007-01-01)
      A series of studies were performed to investigate the effect of transport on liveweight, physiological and haematological responses of cattle.
    • Animal Welfare Guidelines for Beef Producing Farms

      Fallon, Richard J.; Earley, Bernadette; Finnerty, Martina (Teagasc, 1998-10-01)
      The scientific consideration of farm animal welfare is important, due to ethical obligation to maximise health and well-being and eliminate suffering in animals that are under human stewardship, fulfil the requirements and demands of the general community and improve the efficiency of animal agriculture by optimising animal health and productivity. The welfare guidelines are intended to enable farmers to adopt the highest standards of animal health and welfare.
    • Aspects of management options for pasture-based dairy production stocked at two cows per hectare

      Humphreys, James; Lawless, Aidan; Healy, M.; Boland, A.; McNamara, K. (Teagasc, 2007-01-01)
      White clover in association with Rhizobium bacteria have the capacity to fix or convent atmospheric N into plant available N. This can make a considerable contribution to sward productivity. One of the objectives of this experiment was to determine the upper carrying capacity of grass-white clover swards receiving 90 kg fertilizer N/ha. A second objective was to examine the impact of grass-clover swards on mineral-N in the soil and losses of nitrate-N from soil to drainage water during the winter. This experiment was conducted at Solohead Research Farm. There were three treatments: (i) A grass-only treatment (FN) stocked at 2.0 cows per ha in 2003 and 2.2 cows per ha during 2004, 2005 and 2006. This treatment received an average of 226 kg per ha of fertilizer N per year during these years. (ii) A grass-clover treatment (WC) stocked at the same rates as FN and received an average of 90 kg per ha of fertilizer N per year during the experiment. (iii) A grass-only treatment (CC) that was gradually converted over to grass-clover during the experiment and stocked at 2.0 cows per ha throughout the experiment. Fertilizer N input was gradually lowered from 150 kg per ha in 2003 to a target of 90 kg per ha in 2005 and 2006.
    • Baled Silage - Development Of Reliable Baled Silage Systems

      O'Kiely, Padraig; Forristal, Dermot; Lenehan, J.J. (Teagasc, 1999-05-01)
      Baled silage is now made on two-thirds of all farms in Ireland, and accounts for one third of all silage made. It is particularly prevalent as the primary silage-making system on both beef farms and smaller-sized farms. However, it is also widespread as a second silage-making system on many other farms. The series of experiments contained in this report were conducted as part of a collaborative EU Structural Funds supported research project jointly carried out between the Teagasc research centres at Grange and Oak Park. Some of the research was also conducted in collaboration with the Botany Dept. at University College Dublin.
    • Beef Cross Breeding of Dairy And Beef Cows

      Keane, Michael G. (Teagasc, 2011-03)
      The rationale for crossing dairy cows with beef bulls is to increase the beef productivity and value of the progeny. The proportion of dairy cows available for beef crossing is determined by the dairy herd replacement rate. The performance of cross-bred cattle is generally superior to the mean of the parent breeds because of heterosis. This is most pronounced for reproduction, maternal and calf survival traits. Crossing dairy cows with early maturing beef breeds (e.g. Angus, Hereford) has little effect on growth but improves carcass conformation and reduces feed intake. Crossing with most late maturing beef breeds also improves carcass conformation and reduces feed intake, but in addition, growth rate, kill-out proportion and carcass muscle proportion are increased. Cross breeding can have small negative effects on dam milk production, and subsequent reproduction can be impaired following a long gestation or difficult calving. There is little advantage in crossing with double muscled sire breeds (e.g. Belgian Blue, Piedmontese) compared with the larger conventional late maturing breeds (e.g. Charolais, Blonde d'Aquitaine). There are few effects of sire breed on meat quality.
    • Beef production from feedstuffs conserved using new technologies to reduce negative environmental impacts

      O'Kiely, Padraig; Crosson, Paul; Hamilton, William J.; Little, Enda; Stacey, Pamela; Walsh, Karl; Black, Alistair D.; Crowley, James C.; Drennan, Michael J; Forristal, Dermot P.; Hackett, Richard; McGee, Mark; Moloney, Aidan P; O'Brien, Martin; O'Riordan, Edward G.; Rice, B.; Schulte, Rogier P. O. (Teagasc, 2007-12-01)
      The three separate components with parallel objectives to this programme were to: 1. Develop technologies for conserving and optimally feeding alternative/complimentary feedstuffs to grass silage. 2. Quantify the use and re-use of plastic sheeting or film used to seal ensiled feedstuffs or mulch maize, and evaluate some new options. 3. Develop computer programs that will facilitate investigating prototype models of forage-based beef production systems.
    • Biodegradable Microparticles as Non-Live Viral Vectors for Respiratory Tract Vaccination.

      Earley, Bernadette; Kavanagh, Owen; Adair, Brian (Teagasc, 2001-03-01)
      The potential of a microparticulate vaccine delivery system in eliciting a specific humoral response in the upper respiratory tract of calves was evaluated. Microparticles composed of poly(lactideco- glycolide) containing ovalbumin, a model immunogen, were prepared by a solvent evaporation technique. The microparticles were under 10μm in diameter as determined by fluorescence activated cell sorter (FACS) analysis. Following immunisation, the microparticles induced production of specific secretory IgA (sIgA) in nasal samples.The sIgA was detected after only one week and persisted throughout the length of the study. Additionally, the effects of microencapsulated synthetic peptides (F peptide (0.5mg) and G peptide (0.5mg), representing known protective epitopes against bovine respiratory syncytial virus (BRSV), on the cellular and humoral immune responses of calves were investigated. ∗ No significant change in the cellular immune response was detected. * The secretory IgA response was significantly more prolonged following administration of the SF (F111-148) peptide when compared with the SG (G174-187) peptide. * It is concluded that microparticles incorporating antigens show potential in the quest for generating complete protection in the young bovine against respiratory tract pathogens. * Vaccination of calves with the SF (F111-148) and SG (G174-187) peptide resulted in a significant reduction in the requirement to treat with antibiotics for respiratory disease in the post-vaccination period.
    • Biotechnology in Cattle Reproduction.

      Morris, D.G.; Diskin, Michael G.; Sreenan, J.M. (Teagasc, 2001-12-01)
      Over the next decade the Irish agri-food industry will have to compete in a rapidly changing world environment arising from increased competitiveness, decreased world market prices and increased consumer demands for higher quality, healthier and safer food. To become competitive in this environment the scale and efficiency of production at both farm and factory level will have to increase significantly and this must be achieved with due regard for the protection of the environment and the welfare of animals. New technologies will be needed to achieve this. Biotechnology will be central to the development of these new technologies. This project has been concerned with the identification and evaluation of biotechnology developments that have the potential to increase reproductive efficiency in cattle. This includes a range of technologies relating to the in vitro production, manipulation, cryopreservation and transfer of cattle embryos. The potential of other emerging technologies such as embryo and sperm sexing, cloning and biopharming or the production of commercially desirable proteins in cows milk are also addressed in this report.
    • Breed compostition of the Irish cattle herd.

      Drennan, M.J. (Teagasc, 1999-12-01)
      Information was collected on cow and sire breeds in both dairy and suckler herds in the National Farm Survey (NFS) in autumn 1998. The number of farms included in the analysis was 1030 with farms containing less than 2 economic size units (equivalent to 3 to 4 dairy cows) excluded from the sample. The main findings of the survey were as follows: • Ninety-eight percent of dairy cows and 96% of dairy herd replacements were Friesian/Holstein • The suckler cow herd contained 46% early-maturing breed crosses (Hereford 31%, Aberdeen Angus 12% and Shorthorn 3%) 2% Friesians, 48% of the three main continental breed crosses (Charolais 17%, Simmental 16%, Limousin 15%) and 4% other (mainly continental crosses). Compared to the adult cows herd replacements had less early-maturing breed crosses and Friesians (total 42%) and more (55%) of the three main continental breed crosses (Charolais 20%, Simmental 15%, Limousin 20%). • Overall, in 1998, it was estimated that the national cow herd consisted of 52% Friesian/Holstein, 23% early maturing breed crosses and 26% late maturing breed crosses. • Forty-seven percent of dairy cows were bred to Friesian/Holstein sires, 26% were bred to early maturing sire breeds and 27% were bred to continental sire breeds. The corresponding figure for dairy herd replacements were 40%, 46% and 13%. • Seventeen percent of suckler cows were bred to early maturing sire breeds, 46% were bred to Charolais, 16% were bred to Simmental, 17% were bred to Limousin and the remaining 6% were bred to mainly other continental breed sires. The sires used on suckler herd replacements were 43% early maturing breeds, 16% Charolais, 10% Simmental, 25% Limousin and 5% other. • Based on the sire breeds used in 1998, the breed composition of the 1999 calf crop was estimated to be 24% Friesian/Holstein, 24% early maturing breeds, 24% Charolais cross, 10% Simmental cross, 12% Limousin cross and 6% other (mainly other continental crosses). • Although the proportion of continental breed crosses in the calf crop continues to increase (48% in 1993 to 52% in 1999), the use of continental sire breeds is declining in the dairy herd (from 33% in 1992 to 27% in 1998), particularly where AI is the method of breeding. However, this trend may be at an end as the 1999 AI figures to date (September 30) show substantial decreases in Hereford and Aberdeen Angus inseminations with increases in Belgian Blue, Limousin and Friesian/Holstein. • The dairy herd is a relatively unimportant source of the better quality animals accounting for only 25% of total continental breed crosses which have a lower proportion of continental breed genes than those from the suckler herd. • It was estimated that the 1999 calf crop from the suckler herd consisted of 18% early maturing breeds, 29% of half to threequarters continental breed genes and 53% containing at least three-quarters continental breed genes. • A total of 48,200 herds used bulls. The proportion of bulls of each breed used were 9% Frieisan/Holstein, 17% Hereford, 11% Aberdeen Angus, 1% Shorthorn, 29% Charolais, 12% Simmental, 16% Limousin and 5% other. Continental breeds accounted for 38% and 84% of bulls on dairy and suckler farm, respectively. • In the present study the number of animals (cows plus replacements) bred to continental sire breeds was 1.22 million of which 40% were by AI. • National AI figures show that the total number of inseminations (excluding DIY) have declined from 1.03 million in 1992 to 0.79 million in 1998. • Assuming that the suckler cow should be at least half continental breeding and that Belgian Blue crosses are unsuitable if increases in calving problems are to be avoided then the dair y herd may provide as little as 25% of suitable suckler herd replacements. Thus, the main source of replacements would be from within the suckler herd. Factors to be considered include hybrid vigour which involves crossbreeding, milk production potential of the cow and the fact that the most widely used terminal sire is Charolais. In these circumstances one suitable crossbred cow would be obtained from alternate crossing with Limousin and Simmental sires. • Heat synchronisation was used on 3% of herds. The figures for dairy and suckler herds was 6.8% and 0.5%, respectively. • Vaccination for leptospirosis was used on 29% of dairy farms and 4% of suckler farms.
    • Calf Health and Immunity.

      Earley, Bernadette; Fallon, Richard J. (Teagasc, 1999-11-01)
      Suckled calves had significantly higher serum IgG 1 concentrations than mart purchased dairy calves. The marked differences in immunoglobulin levels between suckled calves and dairy calves suggest that these calves received either insufficient quality or quantity of colostral immunoglobulins. Factors affecting calf serum Ig concentrations are, Ig concentration in colostrum, colostrum intake, Ig mass, calf age at first feeding, nutrition of the dam, method of ingestion, presence of the dam, age of the dam and the calf. When suckled calves were fed a similar volume of colostrum relative to birth weight (40 ml/kg) and at the same time interval post birth, there was no significant difference across the three suckler herd progeny for IgG1, IgA and IgM and total Ig serum levels at 28 and 56 days of age. However, serum IgG2 levels were significantly lower in the Limousin x beef breed when compared with the Charolais x beef breed suckled calves at 28 days of age. Healthy calves had higher serum immunoglobulins (IgG1) than calves treated for respiratory disease, enteric disease or for both respiratory disease and enteric disease. It is well recognised that immunoglobulins are absorbed from the intestine for only a short period post birth and that efficiency of absorption is dependent on ensuring that the calf receives adequate colostrum in the immediate post-partum period. Low serum IgG1 concentrations are attributable to failures to obtain adequate colostral immunoglobulins in the period immediately following birth. The mean IgA and IgM serum levels of suckled calves in the present study were only slightly higher than dairy calves while IgG1 serum levels were almost approximately twice as high. Feeding colostrum high in Ig results in higher calf serum Ig concentrations at 48h. The low serum Ig levels reported in the present study suggest that dairy calves failed to obtain adequate transfer of colostral immunoglobulins. Calves with a lower immune status are more susceptible to neonatal infection and thus the importance of colostrum in the immediate post partum period cannot be overemphasised. Thus, the identification of calves with low levels of immunity might stimulate calf producers to ensure that calves receive adequate levels of colostral immunoglobulins. The implications of the present findings are that compared with suckled calves, dairy calves are not receiving 1). adequate quantity of colostrum 2). adequate quality of colostrum. 3). Colostrum soon enough post birth 4). or a combination of all of the previous factors. Rearing calves outdoors using calf jackets had no beneficial effect on calf performance. The incidence of respiratory disease was higher in calves reared indoor when compared with calves reared outdoor with and without jackets. There was an increased incidence of diarrhoea in calves reared outdoors irrespective of calf jacket. Lymphocytes from calves with respiratory disease manifest an impaired capability to blast in vitro. Chromium (Cr) supplementation (250 mg/kg dry matter intake) enhanced the blastogenic response in healthy calves, while, calves with respiratory had impaired blastogenic responses. Supplementation with organic Cr (250 mg/kg dry matter intake) for 63 days had no major effect on physiological parameters and had select effects on haematological parameters, namely, the % monocytes. The % monocytes were significantly higher in the standard commercial milk replacer (CMR) (Skim) Cr supplemented calves when compared with the whey based (CMR) + Soya Brand B or whey based CMR + Soya Brand C or whey based enzyme processed soya Brand C + Cr treatment groups.
    • Cattle Embryo Growth Development and Viabilty.

      Morris, D.G.; Grealy, M.; Leese, H.J.; Diskin, Michael G.; Sreenan, J.M. (Teagasc, 2001-06-01)
      A major problem for the cattle breeding industry is the high rate of early embryo loss which compromises reproductive efficiency and genetic improvement, resulting in serious financial loss to farmers. An important part of the Teagasc research programme in this area is the investigation of basic parameters of cattle embryo growth, development and viability during the critical period when most of the embryo loss occurs. We have now characterised this period of embryo development and to our knowledge, this is the first report describing the morphology, growth rate, protein content and metabolic activity of cattle embryos during this period. The main results are summarised here and detailed results have been published in the papers listed at the end of this report. Embryo growth rate and protein content increased exponentially between days 8 and 13 after fertilisation. Furthermore, there was a high rate of protein synthetic activity, energy and amino acid metabolism and signal transduction activity, all reaching a peak between days 8 and 13 after fertilisation. Because of the high rate of metabolic activity evident during this time it is likely that the embryos are very susceptible to environmental changes that have the potential to interfere with normal developmental mechanisms. The results arising from this project suggest that the critical period of early embryo loss in cattle may now be narrowed to a time window of day 8 to 13 rather than day 8 to 16 as presumed up to now. The main results are summarised.
    • Characterisation of feedstuffs for ruminants.

      Moloney, Aidan P.; Woods, V.B.; O'Mara, Frank P. (Teagasc, 2001-05-01)
      A wide variety of feed ingredients are used in the manufacture of compound feeds in Ireland. Unprocessed feedstuffs vary from batch to batch due to differences caused by variety, soils, weather, etc. By -product feeds may also vary due to the processes from which they were produced. Accurate information on the nutritive value of feeds is essential for accurate ration formulation. A series of experiments was carried out to determine various nutritional characteristics of concentrate ingredients either locally produced or imported into Ireland. From these experiments it was concluded that : * The digestibility values of concentrate ingredients derived in maintenance-fed sheep are applicable to maintenance-fed cattle. * Feed is not utilised as efficiently when the level of feeding is increased from maintenance to 2 x maintenance. * The improved feed conversion efficiency in steers offered a restricted allowance of concentrates cannot be attributed to a difference in digestibility but can be attributed in part to a lower rate of fat deposition compared to steers offered ad libitum concentrates. * The residue after oil extraction from Camelina sativa could replace some imported protein-rich feedstuffs in ruminant rations but to fully achieve this potential, the residual oil content must be decreased. * For measurement of ruminal degradability of concentrate ingredients a wide range of forage to concentrate ratios and feeding levels can be used. * It is important to consider the actual outflow rate of nutrients from the rumen when measuring the feed value of individual concentrate ingredients as this can have an impact on the effective degradability and the relative nutritive values assigned to such ingredients. * Large variations in ruminal degradation occur within and among feeds. The ruminal degradability of different samples of any one feed should be measured to determine their true nutritive value for feeding ruminants. * Within most concentrate ingredients examined, the variation in small intestinal digestibility (SID) due to source indicates a range in the quantity of amino acids supplied to the animal for productive purposes. The more rapid and cost effective in vitro technique can be used to screen the SID of concentrate ingredients. * Target volatile fatty acid (VFA) concentrations and proportions may be produced by varying the proportions of the individual ingredients in a concentrate ration. * An in vitro procedure allowed VFA production to be measured across a large range of feeds under standardised conditions. * On average, 75% of gas produced during ruminal fermentation consists of carbon dioxide. The variation in methane production among individual concentrate ingredients provides an opportunity to formulate rations to minimize environmental pollution with methane.
    • Chemical Composition and Processability of Milks from Herds with Different Calving Patterns.

      O'Brien, B. (Teagasc, 1999-04-01)
      The primary objective of this project was to research the detailed composition and processability of milk produced by spring calving, autumn calving and combined herds. This information is required as it may influence the future value of milk and allow informed decisions to be made by the dairy industry regarding diversification of the present product range. Specific issues to be established included (i) the processing characteristics of late lactation milk from well managed spring and autumn-calved herds and the lactation stage cutoff point for product manufacture from such milks, based on quality and functionality, (ii) the processing characteristics of mid and early lactation milk from well managed spring and autumn-calved herds, respectively, (iii) the volume of early lactation milk required to mix with late lactation milk in order to maintain milk processing quality and (iv) the difference (if any) in processing characteristics of bulk spring/autumn milks mixed at the farm or the processing plant. By maintaining spring-calved cows on a good plane of nutrition in late lactation, milk yield, composition and processing characteristics and quality of Mozzarella cheese can be sustained until late November/early December (~275 DIM [days in milk]). In general there were no notable adverse effects of stage of lactation on the composition or processing characteristics of late lactation autumn milk or on the quality and functionality of Mozzarella cheese made from it, during the lactation period 240-330 DIM (up to mid/late August). Early lactation autumn and mid lactation spring milks generally had better processing characteristics than late lactation spring and autumn milks, respectively. Combining early lactation milk with late lactation milk improved the processing characteristics of the late lactation milk and overcame any processing problems associated with it. Approximately 70 % of autumn milk is required in a spring/autumn bulk milk to maintain processability and to improve the milk sufficiently for cheesemaking from 275 DIM of the spring lactation. Mixing of late lactation spring milk with early lactation autumn milk at the factory from separate herds would result in similar processing characteristics to milk from a mixed spring and autumn calving herd. In conclusion, the manufacturing period for spring milk in late autumn/winter may be extended by good herd management practices on-farm. In addition, the production of autumn milk in combination with this allows a further extension of the manufacturing period. Alternatively, autumn milk may be used exclusively for short shelf-life products. This information suggests that it is possible to overcome the traditional milk processing problems experienced due to the seasonal pattern of milk production in Ireland.
    • Comparison of breed of dairy cow under grass-based spring milk production systems

      Buckley, Frank; Walsh, S.; Dillon, Pat (Teagasc, 2006-01-01)
      The objective of this study was to investigate the potential differences among different dairy cow breeds across two feeding systems on milk production, udder health, milking characteristics, body weight, body condition score, hormone parameters, ovarian function, survival and overall reproductive efficiency. The breeds investigated included Holstein-Friesian (HF), Montbéliarde (MB), Normande (NM), Norwegian Red (NRF) and Holstein- Friesian × Montbéliarde (MBX) and Holstein- Friesian × Normande (NMX). Selection within the HF breed has, until recently, been predominantly for milk production with little or no direct selection for functional traits other than those correlated with superior type. The MB and the NM have been simultaneously selected for both milk and beef production in the past. The NRF were imported as calves and come from a more balanced total merit index incorporating production and cow functionality since the early 1970s. The dairy cow breeds were grouped into blocks of two within breed groups and randomized across two spring-calving grass-based feeding systems: low concentrate feeding system (LC) and high concentrate feeding system (HC). Those on LC feeding system were offered approximately 530 kg/cow over the total lactation, while those on HC feeding system were offered approximately 1030 kg/cow.
    • Comparison of breed of dairy cow under grass-based spring milk production systems.

      Buckley, Frank; Walsh, S.; Dillon, Pat (Teagasc, 2006-01)
      The objective of this study was to investigate the potential differences among different dairy cow breeds across two feeding systems on milk production, udder health, milking characteristics, body weight, body condition score, hormone parameters, ovarian function, survival and overall reproductive efficiency. The breeds investigated included Holstein-Friesian (HF), Montbéliarde (MB), Normande (NM), Norwegian Red (NRF) and Holstein- Friesian × Montbéliarde (MBX) and Holstein- Friesian × Normande (NMX). Selection within the HF breed has, until recently, been predominantly for milk production with little or no direct selection for functional traits other than those correlated with superior type. The MB and the NM have been simultaneously selected for both milk and beef production in the past. The NRF were imported as calves and come from a more balanced total merit index incorporating production and cow functionality since the early 1970s. The dairy cow breeds were grouped into blocks of two within breed groups and randomized across two spring-calving grass-based feeding systems: low concentrate feeding system (LC) and high concentrate feeding system (HC). Those on LC feeding system were offered approximately 530 kg/cow over the total lactation, while those on HC feeding system were offered approximately 1030 kg/cow. There was no genotype by environment interaction observed for any of the milk production, BCS, BW, udder health, milking characteristics, reproductive performance or feed intake/efficiency parameters investigated. Compared to the MB and NM, all other breeds had higher total lactation milk, fat, protein and lactose yield, with the HF having the highest. Animals on the HC feeding system had higher total lactation milk, fat, protein and lactose yield. Compared to the NRF, SCS was higher for the HF, NM, MBX and NMX breed groups, while SCS of the MB was not different. The NM and MB had lower AMF compared to all breeds. The crossbreds achieved the higher AMF. The NM had the lowest PMF, while that of the crossbreds were higher compared to all breeds. Milking duration was not affected by breed. Differences between breeds for AMF, PMF and MD were not apparent after adjustment for milk yield. Animals offered a HC diet had higher AMF, PMF and MD compared to those on the LC feeding system. Somatic cell score did not differ between the feeding systems. The interaction between breed and milk yield influenced SCS, AMF, PMF and MD thus implying that for each unit increase of milk yield by breed, the response in SCS, AMF, PMF and MD was different for some breeds. The response in SCS was similar for the NRF, MBX and NMX, while MD was similar for the MB and MBX. The effect of one unit increase in daily average milk yield caused a favourable decrease in SCS; however a one unit increase in PMF and MD did not influence SCS. No interactions were observed for breed with any milking characteristic on SCS. The HF had the lowest BCS, the MB and NM the highest, while the NRF, MBX and NMX were intermediate. The NRF had the lowest BW; the NM had the highest while the other breeds were intermediate. The NRF had increased likelihood of SR24, PREG1, PREG42 and FINALPR and greater survival compared to the HF. Both MBX and NMX had shorter CSI and CCI and were more likely to be pregnant at the end of the breeding season, thus had higher survival rates compared to the HF; however heterosis estimates for these traits was not significant, likely due to the small data size. Feed system did not influence reproductive performance of the different breeds. Breed of dairy cow did not influence any of the ovarian parameters studied. Breed of dairy cow did not influence insulin or IGF-1 concentrations at any sampling period. Breed significantly effected gestation length, calf birth weight and calving ease score. The NRF had the shortest gestation, lightest calves and least calving difficulty. Genotype had a significant effect on estimated dry matter intake, being highest with the HF, MBX, NMX and lowest with NM and NRF. Genotype also had a significant effect on yield of milk solids per kg of DMI. The highest yield of milk solids per kg of DMI was achieved with the NRF, HF and MBX. Comparisons between genotypes reveal that estimated residual feed intake estimates were lowest (most favourable) for the NRF, compared to other genotypes with the exception of HF.
    • A comparison of Charolais and beef X Friesian suckler cows.

      Drennan, Michael J.; Fallon, Richard J. (Teagasc, 1998-10-01)
      The studies carried out included comparisons of Charolais and Beef x Friesian suckler cows in terms of voluntary silage intake, colostrum yield and immunoglobulin level, calf immunoglobulin level and cow milk yield in addition to animal production experiments. In all experiments the Charolais animals used were a minimum of 7/8 Charolais and were the result of an upgrading programme at Grange commencing with Charolais x Friesians. In the production experiments, only Hereford x Friesian cows (and their progeny) were compared with the Charolais while in all other experiments the Beef x Friesians included both Hereford x Friesians and Limousin x Friesians.
    • A Comparison of the Productivity of Suckler Cows of Different Breed Composition

      Drennan, Michael J; Murphy, B (Teagasc, 2006-01)
      Growth rate and carcass value are important determinants of profitability, with carcasses of good conformation (muscularity) commanding the highest prices on the premium export markets (mainland EU). Therefore, the objective in suckling is that the progeny are of high growth potential and produce carcasses of good conformation. Breed is the major factor influencing conformation, with the late-maturing continental breeds superior to the early-maturing British breeds (Hereford and Aberdeen Angus) and vastly superior to the Friesian/Holstein. The continental breeds also have greater growth potential than the other breeds. The type of carcasses required are similar to those produced from the suckler herd in France where over 80% of cows are purebred Charolais, Limousin or Blonde d'Aquitaine. However, experimental data have shown that the heterosis (hybrid vigour) resulting from use of a crossbred as opposed to purebred cows increases the weight of calf weaned per cow bred by 14%, with a further 8% arising from using a third breed of sire on a crossbred cow. Because of the emphasis on conformation, producers are retaining replacements from within the herds with a tendency towards purebreds rather than crossbreds. It is thus important to examine the relative productivity of various crossbred and purebred cows to provide clear guidelines on the most desirable breeding programme for the suckler herd. The project involved 5 cow breed types (0.5, 0.75 and 1.0 Limousin genes, Simmental x (Limousin x Friesian) and purebred Charolais) with a common sire used on all cows. Progeny were taken to slaughter. The usefulness of ultrasonic scanning and visual muscular scoring in predicting carcass conformation, fat and composition was also examined.