Post-weaning performance and carcass characteristics of steer progency from different suckler cow breed types

peer-reviewedIn two experiments a total of 44 steer progeny of spring-calving Charolais (C) and Hereford × Friesian (HF) suckler cows and C sires were slaughtered at approximately 2 years of age. Following weaning they were offered silage and 1 kg of concentrate per head daily during a 5 month winter after which they spent 7 months at pasture. In Experiment 1, animals were given a silage/concentrate diet during a finishing period of either 95 or 152 days. In Experiment 2, steers were offered either a daily diet of silage plus 6 kg of concentrates or concentrates to appetite plus 5 kg of silage (fresh weight) during the final 140-day finishing period. Following slaughter, an 8-rib pistola from each animal was dissected. For the two experiments combined C and HF progeny had carcass weights of 372 and 385 (s.e. 6.1) kg, proportions of carcass as pistola of 467 and 454 (s.e. 2.8) g/kg and pistola meat proportions of 676 and 642 (s.e. 5.1) g/kg, respectively. All fat traits were lower for the C than HF progeny but there was no difference in carcass conformation score. Increasing slaughter weight increased carcass weight (P < 0.001), kidney plus channel fat weight (P < 0.001), and pistola fat proportion (P < 0.001) and decreased the proportions of carcass as pistola (P < 0.05), pistola meat (P < 0.01), and bone (P < 0.05). In conclusion, breed type had no effect on carcass growth but the C progeny had higher meat yield than the HF. Increasing slaughter weight increased fatness and reduced meat yield

Production and carcass traits of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais × Holstein-Friesian male cattle

peer-reviewedThe increased proportion of Holstein genetic material in the dairy herd has consequences for beef production in Ireland. A total of 72 spring-born male calves (24 Holsteins (HO), 24 Friesian (FR) and 24 Charolais × Holstein-Friesians (CH)) were reared from calfhood to slaughter. Calves were artificially reared indoors and spent their first summer at pasture following which they were assigned, on a breed basis, to a factorial combination of two production systems (intensive 19-month bull beef and extensive 25-month steer beef) and two slaughter weights (560 and 650 kg). After slaughter the pistola hind quarter was separated into fat, bone and muscle. Live-weight gain, carcass gain, kill-out proportion, carcass conformation and carcass fat scores were 830, 811 and 859 (s.e. 14.9) g/day, 540, 533, 585 (s.e. 7.7) g/day, 526, 538 and 561 (s.e. 3.0) g/kg, 1.51, 2.18 and 2.96 (s.e. 0.085), and 3.40, 4.25 and 4.06 (s.e. 0.104) for HO, FR and CH, respectively. Corresponding values for pistola weight as a proportion of carcass weight, pistola muscle proportion and pistola fat proportion were 458, 459 and 461 (s.e. 2.6) g/kg, 657, 645 and 667 (s.e. 3.7) g/kg, and 132, 161 and 145 (s.e. 4.1) g/kg. Compared with the intensive system, animals on the extensive system had a lower (P < 0.001) daily live-weight gain, kill-out proportion and a lower muscle proportion in the pistola. Increasing slaughter weight increased (P < 0.001) carcass weight and carcass fat score and reduced the proportion of muscle in the pistola. Allometric regression coefficients for pistola weight on side weight, and total bone, muscle and fat weights on pistola weight were 0.898, 0.755, 0.900 and 1.910 respectively. It is concluded that HO grew at least as fast as FR but had a lower killout proportion. Carcass conformation and fat scores were greater for FR than for HO and muscle proportion in the pistola was lower and total fat proportion was higher. Compared with FR, CH had heavier carcasses, a higher kill-out proportion and less fat and more muscle in the pistola

Body and carcass measurements, carcass conformation and tissue distribution of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais x Holstein-Friesian male cattle

peer-reviewedThe increased proportion of Holstein genes in the dairy herd may have undesirable consequences for beef production in Ireland. A total of 72 spring-born calves, (24 Holstein (HO), 24 Friesian (FR) and 24 Charolais X Holstein-Friesian (CH)) were reared from calfhood to slaughter. Calves were artificially reared indoors and spent their first summer at pasture following which they were assigned to a 3 breeds (HO, FR and CH) 2 production systems (intensive 19-month bull beef and extensive 25-month steer beef) 2 slaughter weights (560 and 650 kg) factorial experiment. Body measurements of all animals were recorded at the same time before the earliest slaughter date. After slaughter, carcasses were graded and measured and the pistola hind-quarter was separated into fat, bone and muscle. HO had significantly higher values for withers height, pelvic height and chest depth than FR, which in turn had higher values than CH. HO had a longer back and a narrower chest than either FR or CH, which were not significantly different. Carcass length and depth, pistola length, and leg length were 139.2, 134.4 and 132.0 (s.e. 0.81), 52.1, 51.3 and 47.7 (s.e. 0.38), 114.4, 109.0 and 107.0 (s.e. 0.65) and 76.7, 71.9 and 71.4 (s.e. 0.44) cm for HO, FR and CH, respectively. Breed differences in pistola tissue distribution between the joints were small and confined to the distal pelvic limb and ribs. There were relatively small breed differences in the distribution of pistola muscle weight between individual muscles. Body measurements were significantly greater for animals on the intensive system (bulls) than the extensive system (steers) in absolute terms, but the opposite was so when they were expressed relative to live weight. The only significant difference in relative carcass measurements between the production systems was for carcass depth, which was lower for the intensive compared with the extensive system. Increasing slaughter weight significantly increased all carcass measurements in absolute terms but reduced them relative to weight. It is concluded that there were large differences between the breed types in body and carcass measurements, and hence in carcass shape and compactness but differences in tissue distribution were small

Non-carcass parts and carcass composition of high dairy genetic merit Holstein, standard dairy genetic merit Friesian and Charolais × Holstein-Friesian steers

peer-reviewedThe increased use of Holstein genetic material in the dairy herd has consequences for beef production. A total of 24 spring-born calves comprising 8 Holsteins (HO), 8 Friesians (FR) and 8 Charolais × Holstein-Friesians (CH) were reared from calfhood to slaughter. At the end of the second grazing season they were assigned to a 3 (breeds; HO, FR and CH) × 2 (slaughter weights; 620 and 730 kg) factorial experiment and fin¬ished indoors. After slaughter carcasses were classified for conformation and fatness, all organs and non-carcass parts were weighed, and the right side of each carcass was dissected into fat, bone and muscle. Non-carcass parts, carcass weight, kill-out propor¬tion, carcass conformation score and m. longissimus area were 405, 398 and 368 (s.e. 8.31) g/kg empty body weight, 355, 344 and 383 (s.e. 9.4) kg, 509, 520 and 545 (s.e. 8.99) g/kg, 1.0, 2.0 and 3.1 (s.e. 0.16), 7616, 7096 and 9286 (s.e. 223.4) mm2 for HO, FR and CH, respectively. Corresponding proportions of carcass muscle and fat were 631, 614 and 656 (s.e. 8.4), and 165, 200 and 165 (s.e. 10.5) g/kg. Increasing slaughter weight increased the proportion of total non-carcass parts, carcass weight, carcass fat score and fat proportion, and reduced carcass muscle and bone proportions. It is concluded that differences in kill-out proportion between the two dairy breeds was primarily due to the lower proportion of gastrointestinal tract (GIT) in FR, and the higher kill-out proportion of CH was mainly due to lower proportions of GIT, internal organs and internal fat. In terms of beef production, HO and FR were broadly comparable for most traits except carcass conformation score and carcass fat proportion, which were lower for HO. CH was superior to the dairy breeds in all important production traits

The relationship between various live animal scores/measurements and carcass classification for conformation and fatness with meat yield and distribution, and ultimate carcass value

End of project reportAccordingly, the primary objectives of the following study were to: (1) determine the relationship of live animal muscular and skeletal scores, ultrasonically scanned muscle and fat depth measurements of the m. longissimus dorsi, and carcass conformation and fat scores with kill-out proportion, carcass composition and value. (2) Specifically develop and test the accuracy of prediction equations for carcass meat, fat and bone proportions, derived from carcass conformation and fat scores, and develop prediction equations for total carcass composition from hind-quarter composition

Efficient Beef Production from Temperate Grasslands in North-Western Europe

Ireland’s cool temperate maritime climate is conducive to grass growth and, as a result, ruminant livestock systems have evolved that maximise both grazed pastures and conserved grassland forage as winter feed. Most Irish pastures are permanent, capable of achieving high herbage production (Keating and O’Kiely 2000) and, accordingly, supporting intensive livestock production systems. Most male progeny from the 1.1 million Irish dairy herd are reared as steers, typically slaughtered at 24-26 months of age. Approximately 85% of dairy calves available for beef production are spring-born, usually in February/March (AIMS 2011). The progeny of Holstein-Friesian (Ho/Fr) sires account for 0.5-0.6 of the calf crop, with 0.6 and 0.4 of the remainder being sired by early-maturing (EM; e.g. Aberdeen Angus, Hereford) or late-maturing (LM; e.g. Limousin, Belgian Blue, Charolais) sires, respectively. This paper summarises some of the main grassland-based steer beef production systems applicable to Ireland

Effect of floor type on performance, lying time and dirt scores of finishing beef cattle: A meta-analysis

peer-reviewedData from individual studies evaluating the effect of housing systems on performance, lying time and dirt scores of finishing beef cattle are conflicting. The objective of this study was to collate the data from previous animal housing studies and quantify, through meta-analysis, the effect of floor type on animal performance, lying time and dirt scores. From 38 peer-reviewed articles, published between 1969 and 2017, 18 were determined to be eligible for meta-analysis. Papers were included in the study if they contained information on the effect of floor surface on animal performance (average daily liveweight gain (ADG), feed conversion ratio (FCR) and carcass weight), lying behaviour or animal cleanliness. There was no difference (P > 0.10) in ADG, FCR or carcass weight between concrete slatted floors (CSF) and CSF overlaid with rubber mats (RM). Using RM had no effect (P > 0.10) on lying duration or dirt scores of cattle. There was no difference (P > 0.10) in the ADG, FCR, carcass weight, lying duration or cleanliness of cattle housed on CSF or straw bedding. It was concluded that using RM or straw instead of CSF had no effect on performance, lying time or dirt scores

An observational study on passive immunity in Irish suckler beef and dairy calves: Tests for failure of passive transfer of immunity and associations with health and performance

peer-fundedThe study objectives were to: 1) evaluate the diagnostic performance of passive immunity tests for classification of failure of passive transfer (FPT) risk, based on their relationships with calf health and performance, and 2) describe the epidemiology of morbidity and mortality in suckler beef and dairy calves under Irish conditions. A total of 1392 suckler beef calves (n = 111 farms) and 2090 dairy calves (84 farms) were included in this observational study. Blood samples were collected by jugular venipuncture. Serum samples were analysed for total IgG concentration using an ELISA assay, total protein concentration by clinical analyser (TP – CA), globulin concentration, zinc sulphate turbidity (ZST) units, total solids percentage by Brix refractometer (TS – BRIX), and total protein concentration by digital refractometer (TP – DR). Crude and cause-specific morbidity, all-cause mortality, and standardised 205-day body weight (BW) were determined. Generalised linear mixed models were used to evaluate associations between suckler beef and dairy calves for morbidity, mortality, growth and passive immunity. Receiver operating characteristic (ROC) curves were constructed to determine optimal test cut-offs for classification of health and growth outcomes. Overall, 20% of suckler beef and 30% of dairy calves were treated for at least one disease event by 6 mo. of age. Suckler beef calves had greater odds of bovine respiratory disease (BRD; odds ratio (OR), 95% confidence interval (CI): 2.8, 1.2–6.5, P = 0.01), navel infection (5.1, 1.9–13.2, P < 0.001), and joint infection/lameness (3.2, 1.3–7.8, P = 0.01) during the first 6 mo. of life than dairy calves. In addition, from birth to 6 mo. of age, suckler beef calves had greater rates of navel infection (incidence rate ratio (IRR), 95% CI: 3.3, 1.3–8.4, P = 0.01), but decreased rates of diarrhoea (0.9, 0.2–0.9, P = 0.03) compared to dairy calves. Optimal test cut-offs for classification of morbidity and mortality outcomes in suckler beef calves ranged from 8 to 9 mg/ml ELISA, 56 to 61 g/l TP – CA, 26 to 40 g/l globulin, 12 to 18 ZST units, 8.4% TS – BRIX, and 5.3 to 6.3 g/dl TP – DR. Optimal test cut-offs for classification of morbidity and growth outcomes in dairy calves ranged from 10 to 12 mg/ml ELISA, 57 to 60 g/l TP – CA, 29 to 34 g/l globulin, 19 ZST units, 7.8 to 8.4% TS – BRIX, and 5.7 to 5.9 g/dl TP – DR

A Multicriteria Assessment of Forage or Concentrate-Based Finishing Diets for Temperate Pasture-Based Suckler Beef Production Systems

This study evaluated the effect of contrasting ‘finishing’ diets on animal performance, meat nutritional value, land use, food-feed competition, farm economics and greenhouse gas (GHG) emissions in temperate pasture-based suckler weanling-to-steer beef systems. Post-weaning, eight-month-old, spring-born, late-maturing breed steers (333 kg) were assigned to one of three systems: (1) Grass silage + 1.2 kg concentrate DM (148 days), followed by pasture (123 days) and finished on ad libitum concentrates (120 days) - slaughter age, 21 months (GRAIN); (2) as per (1) but pasture (196 days) and finished on grass silage ad libitum + 3.5 kg concentrate DM (124 days) - slaughter age, 24 months (SIL+GRAIN); and (3) grass silage-only (148 days), pasture (196 days), silage-only (140 days) and finished on pasture (97 days) - slaughter age, 28 months (FORAGE). The mean target carcass weight was 390 kg for each system. Data generated was used to parameterise a farm-level beef systems model. Measured concentrate DM intake was 1187, 606 and 0 kg/head, and average daily gain was 0.83, 0.72 and 0.62 kg for GRAIN, SIL+GRAIN and FORAGE, respectively. Direct (pasture) land use was lowest for GRAIN. FORAGE was more profitable and was the only net producer of human edible protein and energy/ha. GRAIN produced the lowest GHG emissions per animal and meat essential amino acid concentration. FORAGE was more favourable for GHG emissions per kg of net (produced vs. consumed) production of human edible protein. Muscle amino acid and saturated fatty acid concentrations did not differ between the production systems, but FORAGE had the highest muscle concentration of omega-3 poly-unsaturated fatty acids. Differences in muscle mineral concentration were small. In conclusion, there are inverse relationships between food-feed competition, land-use, economics and GHG emissions per unit of product among different systems

Calf disbudding and castration

peer-reviewedThe degree of tissue damage associated with disbudding is determined by the stage of development of the horn bud, eg. in younger calves, the burning of the vessels surrounding the horn bud is su icient, whereas the whole bud needs to be removed (by levering it out from the side) when the horn is further developed. Setting definitive ages for disbudding or dehorning is di icult since horn bud development occurs later in beef breeds than in the dairy breeds. Castration of bull calves induces a stress response (increase in the stress hormone, cortisol), which is influenced by the age of the calf. Castration-induced pain may be greater among younger calves compared with older calves because their nervous system and coping mechanisms (stress response) are not fully developed