A. Macdearmid

Intensive beef production 3. Performance of Friesian steers given low-fibre diets

Two groups of twelve-week-old Friesian steer calves were self-fed to a slaughter weight of 400 kg. on diets composed solely of either 85% rolled barley or ground maize and 15% of a supplement providing additionalprotein, calcium, phosphorus, iron, copper, cobalt, salt and vitamin A and vitamin D. There were no health problems on the barley diet, but five of the 15 cattle given maize died from bloat. Surviving animals on the maize diet took 344 days to reach a carcass weight of 231 kg.; comparable data for the barley-fed cattle were 362 days and 222 kg. The tenth rib cuts from the carcasses of cattle given maize contained significantly more fat and less water and ash than comparable cuts from the barley animals. Feed conversion ratio on the barley diet was 4·76. A comparison between the Friesian steers in the present trials and others given a lower energy diet containing ground roughage showed that with increasing concentration of the ration there was an increase in rate of gain, killing-out percentage and content of ether extract in the tenth rib cut.

The use of kidney beans (Phaseolus vulgaris) as protein supplements in diets for young rapidly growing beef steers

Abstract Rolled barley was pelleted with supplementary minerals and vitamins (Diet 1), or with supplements of either soya bean meal (Diet 2) or with 50 or 75% of the supplementary protein supplied by the soya being replaced by protein from kidney beans ( Phaseolus vulgaris L. cv. Processor) (Diets 3 and 4, respectively). The crude protein content of Diet 1 was 11.5% of the dry matter, and in Diets 2, 3 and 4, it was approximately 15%. In Trial 1, groups of four steers with mean live weight 203 ± 4.8 kg were allocated to each of the dietary treatments. Blood samples were obtained from these steers before they received the experimental diets, and 10 and 13 days after they were introduced to the diets. Four days after the steers were offered the diets, six out of the eight steers given diets containing kidney beans were excreting loose watery faeces. All steers given diets containing kidney beans developed anti-lectin antibodies to a varying extent by Day 13 of the trial. In Trial 2, the pelleted diets used in Trial 1 were offered with 2 kg of hay per day to groups of eight steers of similar type and weight. Over a 66-day period, the live-weight gains of steers offered Diets 1–4 were 1.06, 1.28, 1.05 and 0.86 ± 0.11 kg/day, respectively. Steers consumed significantly less of the pellets which contained kidney beans, Treatments 3 and 4 giving intakes of 6.5 and 6.2 kg/day, respectively, compared with 6.8 and 7.1 kg/day for Treatments 1 and 2, respectively. The efficiency of food conversion of steers on Treatments 1–4 was 6.5, 5.6, 6.3 and 8.5, respectively. Incorporating kidney beans in the diets of yearling cattle was detrimental to the health of the cattle and depressed daily live-weight gains.

Intensive beef production. II. Replacement of cereals with ground straw

1. A growth trial was carried out with 21 Friesian steers given diets containing either 0%, 30% or 50% ground straw, and concentrates up to 100%. 2. Steers offered the diet containing 0% straw consumed less dry matter per day than steers on the other two treatments. 3. Rates of live-weight gain were 1·20, 1·04 and 0·87 kg/day for the three treatments respectively, and carcass gains were 690, 550 and 440 g/day. 4. Killing-out percentage dropped and alimentary-tract fill increased as the proportion of straw in the diet increased. 5. The dry-matter digestibility coefficients for the three diets, determined at maximal intake, were 79·1%, 62·3% and 56·6%, respectively.

Intensive beef production. 2. The effect of three, twelve or sixteen week weaning on the performance of Aberdeen-Angus crossbred cattle.

1. Some characteristics are described of 10 steer progeny of a Friesian bull which is known to have carried the factor for muscular hypertrophy. 2. On average these steers had a higher birth weight, lighter hide and liver, smaller feet and cannon bones, a lower percentage of fat and higher percentage of lean in the 10th rib joint, than the progeny of three other Friesian bulls reared at the same time and under the same conditions. 3. No one character was an adequate criterion for separating affected from normal progeny. It appears possible that the bull concerned was homozygous for the double muscling gene, and that all his progeny showed one or more symptoms of the condition.

Turnips with chemically-treated straw for beef production 2. Effect of turnips on the degradability of straw in the rumen

The nylon bag technique was used to determine the effects of offering to steers an allowance of turnips in a diet based on straw on the degradation of dry matter and acid-detergent fibre of the straw. Rumen-cannulated steers were offered basal diets of (a) sodium hydroxide (NaOH)-treated straw ad libitum , (b) NaOH-treated straw plus turnips (50 g dry matter per kg W 0·73 ) offered once daily or (c) turnips ad libitum . Samples of straw, treated with NaOH, anhydrous ammonia (NH 3 ,) or untreated straw were incubated in nylon bags in the rumen along with each of the basal diets. Additionally molasses (66 g dry matter per kg W 0·75 ) was infused into the rumen of the steers offered the NaOH-treated straw. Dry matter and fibre losses of straw from nylon bags were in the order NaOH-treated > NH 3 ,-treated > untreated; there was no interaction ( P > 0·05) between method of straw treatment and effect of basal diet on 40-h or 72-h dry matter or fibre degradability. Supplementation of the basal straw diet with either turnips or molasses depressed ( P P

Intensive beef production. 12. Replacement of concentrates with chopped dried grass.

1. A growth trial was carried out using 24 British Friesian steers given diets containing (1) 100%, (2) 60%, (3) 40% and (4) 0% concentrates and chopped dried grass up to 100%. 2. Daily dry-matter intake was significantly lower for steers on Treatment 1 than for steers on the other three treatments. 3. Rate of live-weight gain declined from 1·18 to 0·88 kg/day and carcass gain from 625 to 430 g/day between steers on Treatments 1 and 4. 4. Killing-out percentage dropped from 55·3% (1) to 51·9% (4) and the 8th-10th rib from steers on Treatments 3 and 4 contained significantly more crude protein and less ether-extractable matter than ribs from steers on Treatments 1 and 2.

Ammonia-treated barley straw and rolled barley offered either together, in a mixed ration, or successively to beef steers

Abstract Barley straw treated with anhydrous ammonia at a rate of 40 g per kg of straw dry matter (DM) and rolled barley were offered to 20 steers weighing initially 350 kg. Each steer was offered in total approximately 600 kg of straw DM and approximately 525 kg of barley DM. Ten steers were offered the straw alone in the long form at the beginning of the trial followed by the rolled barley alone. The remaining 10 steers were offered straw which had been ground through a 40-mm screen and mixed with the rolled barley in a complete diet. Dry matter digestibility coefficients of the ammonia-treated straw and the mixed straw plus barley diet were 0.52 and 0.57 ± 0.026, respectively. The DM digestibility coefficient of rolled grain in the mixed diet was predicted from the digestibility of starch to be 0.78 and the DM digestibility of straw in the mixed diet, determined by difference, was 0.39. Although steers offered the straw followed by rolled barley took on average 39 days longer to consume their total food allowance, cold dressed carcass weights of the two groups were not significantly different nor was there any difference in the carcass composition of the two groups of steers as determined by specific gravity measurements. Maintenance energy requirements were calculated for the two groups of steers and although the same amount of food was consumed by both groups and the energy required for maintenance was higher in the group offered straw followed by barley, the depression in the energy available from straw offered in a mixed diet caused the same total amount of metabolizable energy to be available for carcass gain to both groups.

Anhydrous ammonia-treated whole-crop barley for beef steers

Whole-crop barley (cv. Midas) was harvested when the grain dry matter (DM) reached 640 g/kg and was treated with either anhydrous ammonia at 40 g/kg DM or propionic acid (30 g/kg DM) and stored in polythene-lined tower silos. Anhydrous ammonia and propionic acid preserved the early harvested barley whole crop but distribution of ammonia through the silos was not uniform. Coefficients of DM and starch losses from whole grains separated from the ammonia- or propionic acid-treated whole crops or from rolled barley grains and suspended in the rumen of steers in nylon bags weqe, after 42 h incubation 0.73,0.85,0.26,0.21 and 0.78,0.96 respectively. Coefficients of digestibility of the ammonia-treated (AWC), of the propionic acid-treated (PWC) whole crops and of a diet of rolled barley and ammonia-treated straw (RB) with the same grain to straw DM proportion as that in the whole crops were 0·62 (AWC), 0·55 (PWC) and 0K57 (RB). Daily live-weight gains (kg/day) of 350 kg Hereford × Friesian steers offered the diets for up to 100 days were 0·33 (AWC), ·0·61 (PWC) and 0·74 (RB) and DM feed intakes (kg/day) were 4·7,3·4 and 7·6 respectively.

Cereal straw in diets for beef cattle: effects of pattern of growth and diet formulation on growth rate and food conversion efficiency

Five groups of Hereford × Friesian steers (initial weight 340 kg) were given either a diet of rolled barley and ammonia-treated barley straw (AS) in the ratio 60: 40 ad libitum (ASB) to support continuous growth, or were offered over a 143-day period diets of either (i) AS alone (diet AS) (ii) untreated straw (US) plus cassava (diet USC) (iii) US plus grass silage (diet USS) or US plus fish meal (0·27 kg fish meal per day) (diet USF). Both the AS and US were offered ad libitum and allowances of cassava and silage adjusted to allow the USC and USS steers to match the growth of AS steers. Steers i n the restricted groups (AS, USC, USS and USF) were then given freshly cut grass ad libitum until they reached slaughter weight; some steers required additional hay and barley to reach slaughter weight. Steers in group ASB consumed 7·4 kg dry matter (DM), gained 1·16 kg live weight per day taking 112 days to achieve the 455 kg slaughter weight. AS, USC and USS animals maintained body weight over the restricted period, whereas the USF group tended to lose weight and daily DM intakes were 4·63 kg AS (AS steers); 3·81 kg US plus 0·95 kg cassava (USC steers); 0·86 kg US plus 3·31 kg silage (USS steers); 3·5 kg US plus 0·27 kg fish meal (USF steers). When grass or grass followed by barley plus hay was given the live-weight gains of the previously restricted cattle did not differ (mean 1·0 (s.e. 0·10) kg/day). AS provided proportionately 0·30 of the metabolizable energy used to produce growth rates in excess of 10 kg/day or if given as the sole food maintained cattle without supplementation.