Charolais Cross Steers Research Articles

Relationship between feeding behavior and performance of feedlot steers fed barley-based diets12

The relationship between feeding behavior and performance of 274 feedlot cattle was evaluated using Charolais cross steers from 2 consecutive years averaging 293 ± 41 kg for yr 1 (n = 115) and 349 ± 41 for yr 2 (n = 159). Steers were blocked by BW and assigned to 3 (yr 1) or 4 (yr 2) feedlot pens equipped with a radio frequency identification system (GrowSafe Systems). Each pen contained 5 feeding stalls that allowed individual animal access to a feed tub suspended on load cells. The system recorded animal identification, duration, and frequency of feedings as well as the amount of feed consumed during each visit. Daily variation in DMI (DVI), calculated as the absolute difference in DMI from one day to the next, as well as eating rate were determined for each steer. Barley-based diets were delivered to meet steer ad libitum intake over the 213- and 181-d feeding periods for yr 1 and 2 of the study, respectively. The backgrounding periods included the first 85 and 56 d of yr 1 and 2, respectively, in which steers were fed a 14 to 30% concentrate diet, whereas the finishing periods included the last 116 and 101 d of feeding in yr 1 and 2, respectively, with the diet consisting of 77.9% concentrate. Steers were weighed individually every 14 d. To relate feeding behavior to performance, steers were grouped by ADG and G:F and categorized as high, average, or low (based on 1 SD greater than and less than the mean). In the backgrounding and finishing periods of both years of the study, steers classified as having high ADG exhibited greater (P < 0.001) DVI than steers classified as having average or low ADG. Total daily DMI was also greater (P < 0.001) for steers in the high ADG group than those in the low ADG group. Overall, those steers with the greatest G:F also tended (P = 0.15) to have greater DVI than average or low G:F steers. Compared with average or low G:F steers, DMI by high G:F steers in both years of the study was less during backgrounding, finishing, and overall (P = 0.02). Bunk visits and bunk attendance duration were less frequent and shorter (P ≤ 0.01) overall for high compared with low G:F steers. In this study, steers with more variable eating patterns exhibited greater ADG and tended to have greater G:F, a finding that is contrary to industry perception.

Composition and quality differences between the longissimus and infraspinatus muscles for several groups of pasture-finished cattle

Samples of longissimus (LT) and infraspinatus (IS) muscles from five contrasting groups of pasture-finished cattle (n=7/group) were assessed for quality and composition characteristics in order to determine whether features of pasture-finished beef reported previously apply across different muscles and different classes of cattle. The cattle were not raised together or slaughtered at the same time. Wagyu-cross steers had the highest intramuscular fat levels, particularly in the LT, followed by Angus steers, Charolais-cross steers and Belgian Blue-cross steers, with the lowest levels for Friesian bulls. Relative to the LT, the IS muscle had longer sarcomeres, higher cooking losses, higher concentrations of vitamin E, and lower myofibrillar fragmentation indexes, while its ultimate pH was slightly higher but less variable. Beef from Wagyu-cross steers had the highest chroma values and the lowest shear values, while Friesian bull beef was darkest and least tender. Intramuscular fatty acid composition and concentrations of bioactive compounds such as coenzyme Q10 and carnosine, were similar to those reported previously for cattle finished on New Zealand pastures although taurine levels were lower. Generally concentrations of bioactive compounds differed more between muscles and groups than between cattle finished on pasture or grain as reported previously.

The influence of oscillating dietary protein concentrations on finishing cattle. II. Nutrient retention and ammonia emissions

We hypothesized that oscillation of the dietary CP concentrations would improve efficiency of N use and reduce N loss to the environment. Charolais-cross steers (n = 8; 315 +/- 21 kg of BW) were used in a replicated 4 x 4 Latin square design. The steers were allowed ad libitum access to the following diets: 1) 9.1% CP (low), 2) 11.8% CP (medium), 3) 13.9% CP (high), or 4) low and high oscillated on a 48-h interval on each diet (oscillating). Dry matter intake did not differ among treatments (P = 0.46), but N intake differed (P < 0.01) from 94 (low) to 131 (medium), 142 (high), and 133 g/d (oscillating), as designed. Dry matter digestibility increased (P < 0.01) from 71.8% (low) to 75.8% (medium), 77.7% (high), and 77.5% (oscillating). Nitrogen digestibility increased (P < 0.01) from 62.2% (low) to 67.2% (medium) to 70.1% (high) and 70.9% (oscillating). Nitrogen retention was greater (P < 0.01) in steers fed oscillating (55.0 g/d) than in the steers fed low (34.8 g/ d) or high (40.2 g/d), but N retention of steers fed medium (49.8 g/d) differed (P = 0.02) only from that of steers fed low. Urinary urea N did not differ between steers fed medium (19.5 g/d) or oscillating (21.3 g/d) but was lowest (P < 0.01) for those fed low (8.2 g/d) and greatest for those fed high (39.2 g/d). Daily heat production (kcal/BW(0.75)) tended (P = 0.09) to be less for the steers fed low (177) than those fed medium (189), high (188), or oscillating (182). Cumulative in vitro ammonia volatilization from the manure of steers fed oscillating was lower (P < 0.01) for the initial 5 d of incubation than from manure of those fed medium, but there was no difference after 11 d of incubation. Additionally, there was a decrease (P < 0.01) in in vitro ammonia volatilization as protein concentration in the diet decreased from high to medium to low. These data indicate that oscillation of the dietary protein improved N retention of finishing steers compared with those in high and low N diets and that these changes were great enough to correspondingly alter ammonia volatilization from manure.

The effect of sward surface height on the response to mixed grazing by cattle and sheep

AbstractAn experiment was conducted to examine the effects of mixed grazing of sheep plus cattle under continuous stocking of permanent pasture at different sward heights. The experiment had a 2×3 factorial design, with two sward surface heights (4–5 and 8–10 cm) and three combinations of animal species viz., sheep only, cattle only and sheep plus cattle. There were two replicate plots of each treatment combination and the experiment was conducted over 2 years consecutively. The sheep were Beulah Speckled Face ewes and their single Suffolk-cross lambs while the cattle were yearling Charolais-cross steers. Six ‘core’ steers and six ‘core’ ewes and their lambs grazed plots, as appropriately, while additional, non-experimental steers and ewes and their lambs were used to maintain sward heights. Each year the steers and the ewes grazed the pastures from May to October, while lambs were weaned and removed each year from the experiment in July. There was no significant effect of mixed grazing on live-weight gain of steers, but ewes had significantly higher live-weight gains on the sheep plus cattle treatment than on the sheep-only treatment (82 v. 61 g/day;P&lt;0·001). The live-weight gain of the lambs was higher on the mixed grazing treatment than on the sheep only treatment on the 8–10 cm sward height treatment (243 v. 212 g/day;P&lt;0·05) but there was no significant difference on the 4–5 cm sward height treatment (260 v. 250 g/day;P&gt;0·05). The total output of live-weight gain per ha from steers, ewes and lambs was not significantly affected by animal species combination. It is concluded that while output per ha is not enhanced by mixed grazing by sheep and cattle when sward height is controlled, the live-weight gain of ewes is increased and the live-weight gain of lambs can be increased on taller swards.

Shelf life and eating quality of beef from cattle of different breeds given diets differing in n-3 polyunsaturated fatty acid composition

AbstractTwo experiments were conducted with 32 Charolais cross steers (experiment 1) and 36 Holstein-Friesian and Welsh Black steers (experiment 2) to examine the effects of dietary n-3 polyunsaturated fatty acids (PUFA ) and breed on meat quality. Diets were comprised of grass silage and a concentrate (60 : 40 on a dry-matter basis). Lipid in the concentrate provided 30 g/kg diet dry matter derived from either linseed, fish oil or linseed/fish oil (experiment 1); and linseed or linseed/fish oil (experiment 2). These n-3 PUFA sources were compared with Megalac, a saturated fatty acid control, in both experiments. Diets were offered for 120 days (experiment 1) and 90 days (experiment 2). Measurements of meat quality included fatty acid composition, lipid oxidation and colour during retail display (i.e. shelf life parameters) and eating quality assessed by a trained taste panel. The samples examined were sirloin (longissimus) steaks and minced beef burgers produced from the forequarter muscles infraspinatus, supraspinatus and triceps brachii. The fatty acid results showed that linseed increased the proportion of 18 : 3 n-3 (a -linolenic acid) in neutral lipid of the burgers and approximately doubled it in the phospholipid. Increased synthesis of 20 : 4 n-3 and 20 : 5 n-3 also occurred, raising their levels in the phospholipid. Fish oil doubled the proportions of 20 : 5 n-3 and 22 : 6 n-3, with the linseed/fish oil results intermediate between linseed and fish oil. The Welsh Blacks in experiment 2 had higher proportions of 18 : 3 n-3 in neutral lipid and higher proportions of 18 : 3 n-3, 20 : 5 n-3 and 22 : 5 n-3 in phospholipid. This showed a clear genetic effect on fatty acid composition. The fish oil diet in experiment 1 greatly increased lipid oxidation during retail display in both overwrapped loin steaks and burgers packed in a modified atmosphere. Values for lipid oxidation in the burgers were much higher than in the steaks due to the intimate mixing of phospholipid fatty acids and prooxidants. Lipid oxidation was also greater in the linseed/fish oil samples than controls in both experiments but was similar in linseed and controls. Colour oxidation also proceeded more rapidly in the fish oil samples in experiment 1 and tended to be faster in the linseed/fish oil groups in both experiments. Eating quality was affected by diet in experiment 1 — the fish oil samples eliciting higher scores for ‘fishy’ and ‘rancid’ than controls and having lower ‘overall liking’ scores. Steaks from animals given the linseed diet (with high 18 : 3 n-3 proportions) had the highest ‘overall liking’ scores in experiment 1 but the cattle given linseed for the shorter time in experiment 2 were not different from controls. Despite their different PUFA profile in muscle, Welsh Blacks had similar eating quality scores to Holstein-Friesians which deposited more neutral lipid (marbling fat) in muscle.

Estimation of maintenance energy requirements of beef cattle and sheep

Metabolizable energy intake and heat production were measured in a series of calorimetry experiments carried out at the Agricultural Research Institute of Northern Ireland, Hillsborough, between 1993 and 1996 with beef cattle and sheep. A total of 75 estimates were made with cattle: 23 with Charolais cross steers; 16 with Simmental cross steers and 36 with Angus cross steers (450–628 kg liveweight). Fifty-six estimates were made with lambs: 24 with Blackface cross, eight with Suffolk cross and 24 with Texel cross (23–53 kg liveweight). The diets offered to both cattle and sheep contained proportionately 0·0–0·8 cereal-based concentrates, the remainder being grass silage. Linear regressions of energy retention (measured by calorimetry) against metabolizable energy intake were produced for the cattle and sheep studies. From these linear regressions an estimate of metabolizable energy required for maintenance (MEm) was obtained. For cattle, the derived MEm was 0·614 MJ/kg LW0·75 per day, and for sheep the derived MEm was 0·460 MJ/kg LW/kg LW0·75 per day. The estimates were proportionately 0·34 higher in cattle and 0·32 higher in sheep than the 1990 values of the UK Agricultural and Food Research Council.

The effect of differing forage:concentrate ratio and restricting feed intake on the energy and nitrogen utilization by beef cattle

Six Charolais cross steers (mean live weight 459 kg) were used in a partially balanced changeover design experiment with four 4-week periods. The energy and nitrogen utilization by cattle offered diets differing in forageiconcentrate ( F: C) ratio, but of equal metabolizable energy intake (MEI), were measured. The three diets were (1) high digestibility (D) grass silage offered ad libitum; (2) low D silage offered ad libitum and supplemented with sufficient concentrates to provide the same MEI as (1); (3) high D silage supplemented with the same F: C ratio as (2) and with intake restricted to the same MEI as (1) and (2). These three diet types were offered at two levels of energy intake, the higher level of energy intake having been achieved by adding further concentrates to diets 1 to 3. Gross energy intake (GEI) and faecal, urinary and methane outputs and heat productions were measured in respiration chambers for three days at the end of each period. When values were adjusted to equal MEI across the three diets, animals offered the restricted diet produced significantly less methane, expressed as a proportion of GEI ( P < 0.001), than those offered the other two diets. However, there was no difference in energy retention or the efficiency of utilization of energy for growth between the three diet types used in this study.

Effects of diet and slaughter endpoint on carcass composition and beef quality in Charolais cross steers

One hundred and eight Charolais cross steers were used to compare forage versus grain feeding as affected by slaughter endpoint on carcass composition and palatability attributes of beef. Diets included a 97% alfalfa silage ration or 68% high moisture corn, 25% alfalfa silage ration from start of test to finish or a ration of 97% alfalfa silage from start of test to day 42 of the trial followed by the 68% high moisture corn ration until slaughter. Cattle were slaughtered at either 4, 7, or 10 mm ultrasound backfat. Grain feeding increased (P = 0.01) average daily gain and decreased (P = 0.01) days to finish, while carcass weight and grade fat were similar (P &gt; 0.10) between diets. Palatability attributes were generally unaffected by diet with the exception of slightly less (P = 0.09) beef flavour and more (P = 0.01) off flavour in forage-fed beef versus grain-fed beef. Higher (P = 0.01) concentrations of linolenic acid and lower (P = 0.09) concentrations of oleic acid in forage-fed beef may be partially responsible for diet differences in flavour. As slaughter endpoint increased from 4 to 7 mm backfat, average daily gain, days to finish, and carcass weight increased (P = 0.01). Palatability attributes assessing juiciness and flavour did not differ (P &gt; 0.10) between slaughter endpoints. Beef from cattle slaughtered at 10 mm backfat was rated higher (P &lt; 0.05) for softness, tenderness, and chewiness than beef from cattle slaughtered at 4 and 7 mm finish. Slaughter endpoint effects on "tenderness" attributes may partially explain why less tender beef is entering the marketplace. Key words: Beef cattle, alfalfa, grain, palatability, shear, fatty acids

The effect of spreading sodium bicarbonate over the surface of grass silage on the intake of grass silages by beef cattle

Ten silages were obtained from farms in Northern Ireland. They were selected on the basis of either low pH (< 3.7) or perceived low intakes on the farms. The silages were offered to 100 Charolais cross steers, either with or without the addition of sodium bicarbonate, in a two-period changeover design experiment. The sodium bicarbonate was spread over the surface of the silage at a rate of 250 g per steer day −1. Each period was of a 2-week duration. Dry matter intakes (kg day −1 and g kg −1 liveweight (LW) 0.75) were recorded daily, with intakes on the second week of each period being used in the statistical analysis. Silage dry matter intakes with (+) and without (−) dietary addition of sodium bicarbonate were: 6.27 and 6.16 (SEM = 0.122) kg day −1; 65.8 and 64.7 (SEM = 1.29) g kg −1 LW 0.75. The lack of a significant effect of dietary addition of sodium bicarbonate on the intake of low pH silages suggests that sodium bicarbonate spread over the surface of the silage has no beneficial effect, in terms of intake, with silages of this type.

Tissue specific differences in insulin receptor characteristics in the mature bovine animal

Insulin is believed to play a key role in the partitioning of nutrients towards fat and protein deposition. The biological effects of insulin are a function of plasma insulin concentration, insulin-receptor concentration and the affinity of the receptor. The number and affinity of insulin receptors on adipocytes differs between genetically lean and obese pigs (Camara and Mourot, 1996) while receptor number, but not affinity, was shown to differ in a variety of bovine muscles (Boge et al., 1995). The objective of the current work was to determine if insulin receptor affinity and number vary between the principal target tissues (i.e. liver, muscle and adipose tissue) in the bovine animal.Five Charolais-cross steers were offered grass silage ad libitum from 18 months of age until slaughter, at 701± 22.9 kg, at a commercial abattoir. Samples of liver [L], of two skeletal muscles [Ml, M3] and of subcutaneous [S], omental [0]and renal [R] fats were taken as soon as possible after slaughter (typically &lt;30min for L, M3, S and O and &lt;45min for Mland R), wrapped and snap frozen in liquid nitrogen prior to storage at -70 °. Insulin receptors were partially purified by solubilising tissues in 1% Triton X-100 for 24 hours at 4 °C followed by centrifugation (100000 x g, lh, 4°) and affinity chromatography of the supernatants on 0.5 ml wheatgerm agglutinin Sepharose 6MB columns. Bound receptors were eluted from the column with 0.3M N-acetyl-D-glucosamine. Receptor binding was assessed using a tracer amount of A-14 125I-insulin (∼35 pM) and increasing concentrations of unlabelled insulin (0-10 μM) in a total volume of 150 μl of pH 7.4 buffer as described by Magri et al (1990).

Changes in the body composition of beef cattle during compensatory growth

ABSTRACTForty-two weaned suckled Charolais-cross steers were used to measure changes in body composition during compensatory growth in growing cattle. Six cattle were slaughtered initially and the remaining 36 allocated to either a low level of feeding to 350 kg live weight followed by a high level (LH) or a high level of feeding throughout (HH). Above 350 kg live weight, food intake on both treatments was the same at any given live weight. Six cattle were slaughtered from each treatment at 350, 400 and 450 kg live weight. From initial live weight (259 kg) to 350 kg, live-weight gains were 0·45 and 0·78 kg/day for the LH and HH treatments respectively (P &lt; 0·001). From 350 to 400 kg live weight, live-weight gains were 1·35 and 0·98 kg/day (P &lt; 0·01) for the LH and HH cattle respectively, while from 400 to 450 kg live weight there was no significant difference (1·38 v. 1·20 kg/day). The LH cattle contained less fat in the empty body than the HH cattle at 350 kg (118 v. 153 g/kg; P &lt; 0·05) and 400 kg live weight (117 v. 169 g/kg; P &lt; 0·01), but at 450 kg there was no significant difference between treatments. From 350 to 400 kg live weight the composition of the empty body-weight gain was 663 g water, ' 108 g fat and 216 g protein per kg in the LH cattle and 422 kg water, 311 g fat and 173 g protein in the HH cattle. From 400 to 450 kg live weight the equivalent figures were 491, 291, 156 g/kg for the LH cattle and 744, 67 and 203 g/kg for the HH cattle. The results demonstrate that following a period of food restriction the empty body-weight gain of cattle initially comprises increased proportions of protein and water and a reduced proportion of fat compared with unrestricted cattle when both are given the same amount of food and compared at the same weight. There then follows a second phase in which the proportion of fat increases and the proportions of protein and water decrease.

Meat tenderness and palatability of Swamp buffalo and four breeds of cattle

ABSTRACTSamples of cooked muscle of Swamp buffalo, Hereford, Angus, Friesian and Charolais cross steers were sheared and scored by a taste panel for tenderness, flavour, juiciness and palatability. The cattle were given commercial pellets from 9 months of age to slaughter at 12,15 and 18 months. The buffaloes were fed one of four regimens: all pellets, all hay, 3/4 pellets and 1/4 hay or 1/4 pellets and 3/4 hay from 13 to 22 months of age to slaughter at 20 to 34 months.There was little difference between the buffaloes and the cattle in shear-force or taste panel scores. Age at slaughter had no significant effect on the quality traits measured in either the buffaloes or the cattle. The feeding regime did not influence the tenderness, flavour or palatability of buffalo muscle but the high pellet diets increased juiciness.Shear-force was not influenced by rectal or muscle temperatures, muscle pH, carcass weight or fatness in the buffaloes but fatness reduced shear-force in cattle m. longissimus.Buffalo intramuscular fat increased with age and carcass fatness but had no effect on shear-force or taste panel score.

A note on the effect of early weaning on performance and carcass characteristics in Angus cross and Charolais cross steers

ABSTRACTEight Angus cross and eight Charolais cross steer calves (out of Hereford × British Friesian cross dams) were weaned at turnout when 7 months old. Over a summer grazing period of 182 days these ‘early-weaned’ calves grew 30 to 35 % slower than eight comparable steer calves of each cross which continued to suckle their dams until 11 months of age. At housing, the early-weaned calves were 100 g/kg lighter, but this difference had no effect on growth rates or silage intakes during the 138-day finishing period. At the same age early-weaned steers had reduced hot carcass weight and dressing percentage but a similar proportion of fat in the forerib joint.

Charolais, Friesian and British beef sires for beef production in a Mediterranean environment

British beef breed cow herds, located in the Adelaide Hills and upper south-east areas of South Australia, were mated to Charolais, Friesian and British beef breed sires in two consecutive years. Calving performance of 477 cows and growth and carcase characteristics of the progeny were examined. Assistance at calving was given in 2.7 per cent of the total number of Charolais calvings, 0.7 per cent of purebred calvings and none of the Friesian calvings. The percentage of stillborn calves, and calves dead within twenty-four hours of parturition, sired by Charolais, Friesian and British breed sires was 5.3, 4.6 and 3.7 per cent respectively. Charolais - and Friesian-cross progeny had similar growth rates in both the pre- and post-weaning periods but both crossbreds grew significantly faster than the purebred British breed progeny. When slaughtered at 8 to 10 months of age, Charolais-cross steers yielded significantly more meat than the purebred steers, but at that age, both the Charolais- and Friesian-cross carcases were often too lean (range in depth of backfat of 0.10 to 0.54 cm) to be suitable for the Adelaide market. We concluded that Charolais and Friesian crossbred progeny grow faster and mature later than British breed progeny in the environment studied here, and that both breeds may prove valuable as terminal sires in systematic crossbreeding programmes.