Hereford Cross Steers Research Articles

PSV-13 The influence of diet type on beef cattle performance and meat quality characteristics

Abstract The objective of this study was to determine what additive effect hormonal implants and inclusion of beta-agonists in the diet have on carcass quality in yearling beef steers. Hereford-cross steers [n = 21; initial body weight (BW) = 450 ± 15 kg] were assigned to one of three drylot pens based on initial BW and sire so that each pen had an equal starting BW and sires were equally represented in each pen. Each drylot pen was assigned to one of three treatments: receiving a hormonal implant (IMP), consuming a beta-agonist (BAG), or receiving both of the previous treatments (AND). All steers were fed a mixed ration consisting of 30.0% rye silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement [22.0% CP, 2.90 Mcal ME/kg dry matter (DM)]. Animals were fed daily at 0700 and 1700 h and weighed weekly at 0630 h. For the duration of the trial, animals were housed in drylot pens with ad libitum access to feed and water and had shade structures in each pen. Following a 15-d adaptation period, feed intake was recorded for 45 d. Body weight gain for each treatment group were 1.26, 1.28, and 1.48 kg/d for IMP, BAG, and AND, respectively. Animals on the AND treatment were significantly more feed efficient than the IMP treatment with F:G ratios of 5.9 kg/kg gain and 6.8 kg/kg gain, respectively. After the intake portion of the study was completed, an animal from each pen was slaughtered and evaluated for carcass quality. Hot carcass weights for diets IMP, BAG, and AND were 347.4, 352.9, and 394.8 kg, respectively. Data were analyzed as a completely random design in SAS v9.4. There was not a significant difference between the IMP treatment and the AND treatment based on assessment from Warner-Bratzler shear force, carcass yield, marbling score, and sensory assessment (P > 0.05); however, the BAG treatment had less marbling than the other two treatments. It was concluded that the additive effect of using both a hormonal implant and a beta-agonist can improve feed intake and feedlot performance without detrimental effects on carcass quality.

PSVI-2 Economic evaluation of forage-fed vs concentrate-fed beef finishing systems

Abstract The objective of this study was to determine the economic benefit of implanting beef steers and including a beta-agonist in the finishing diet. To accomplish this, Hereford-cross steers (450 ± 15 kg) were assigned to one of three drylot pens based on initial body weight (BW) and sire so that each pen had an equal starting BW and sires were equally represented in each pen. Each drylot pen was assigned to one of three treatments: receiving a hormonal implant (IMP), consuming a beta-agonist (BAG), or receiving both of the previous treatments (AND). All steers were fed a mixed ration consisting of 30.0% rye silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement [22.0% CP, 2.90 Mcal ME/kg dry matter (DM)]. The data were analyzed in SAS v9.4. Animals were evaluated on intake, growth, and performance measures during a 45-d feeding trial. Average daily gain (ADG) and hot carcass weight differed (P < 0.05) between treatments with AND steers gaining 1.48 kg/d with a hot carcass weight of 394.8 kg, BAG steers gaining 1.28 kg/d with a hot carcass weight of 352.9 kg, and IMP steers gaining 1.26 kg/d with a hot carcass weight of 347.4 kg. The BAG treatment rendered decreased marbling scores than IMP and AND (P < 0.05). It was concluded based on carcass quality data that there was no difference in the IMP and AND treatments, though the AND treatment had greater growth rates and feed conversion rates. Results of this trial are expected to indicate at what price point it becomes economically effective to finish animals using a beta-agonist in conjunction with a hormonal implant.

PSV-6 The additive effect of hormonal implant and inclusion of beta-agonists in carcass quality in beef cattle

Abstract The objective of this study was to determine what additive effect hormonal implants and inclusion of beta-agonists in the diet have on carcass quality in yearling beef steers. Twenty-one Hereford-cross steers (450 ± 15 kg) were assigned to one of three drylot pens based on initial body weight (BW) and sire so that each pen had an equal starting BW and sires were equally represented in each pen. Each drylot pen was assigned to one of three treatments: receiving a hormonal implant (IMP), consuming a beta-agonist (BAG), or receiving both of the previous treatments (AND). All steers were fed a mixed ration consisting of 30.0% rye silage, 28.0% DDGS, 30.0% rolled corn, 10.5% soybean meal, and 1.5% mineral supplement (22.0% CP, 2.90 Mcal ME/kg DM). Animals were fed daily at 0700 and 1700 and weighed weekly at 0630. For the duration of the trial, animals were housed in drylot pens with ad libitum access to feed and water and had shade structures in each pen. Following a 15-d adaptation period, feed intake was recorded for 45 d. Weight gain for each treatment group were 1.26, 1.28, and 1.48 kg/d for IMP, BAG, and AND, respectively. After the intake portion of the study was completed, an animal from each pen was slaughtered and evaluated for carcass quality. Hot carcass weights for diets IMP, BAG, and AND were 347.4, 352.9, and 394.8 kg, respectively. Following 14 d aging, samples from the ribeye area were collected from each animal and subjected to sensory analysis and other assessments of quality. Data were analyzed as a completely random design in SAS v9.4. There was not a significant difference between the IMP treatment and the AND treatment based on assessment from Warner-Bratzler shear force, carcass yield, marbling score, and sensory assessment (P < 0.05); however, the BAG treatment had significantly less marbling than the other two treatments. It was concluded that the additive effect of using both a hormonal implant and a beta-agonist can produce carcass of good quality without detrimental effects on meat quality when compared with a beta-agonist only inclusion.

249 The Effects of Breed and Early Supplementation on Bovine Intramuscular Fat Deposition, Adipogenic and Lipogenic Gene Expression

Abstract Wagyu cattle are known to deposit greater amounts of intramuscular fat, which can directly increase quality grade and carcass value. Supplementation can positively influence animal production and overall nutrient acquisition when used strategically. The objectives of this study were to evaluate 1) the effect of breed and early supplementation on intramuscular and subcutaneous fat deposition in Wagyu and Hereford cross calves, and 2) changes in adipogenic and lipogenic gene expression in longissimus muscle (LM) biopsies from Wagyu and Hereford cross calves during an early supplementation period. Angus cows (n = 34) were artificially inseminated with semen from a Wagyu bull. A Hereford bull was utilized as a clean-up bull. From this breeding, Wagyu cross steers (n = 8) and Hereford cross steers (n = 9) were produced and were placed on study on day 100 of age. At this time, calves were allowed access to four SuperSmart Feeder stalls and were individually supplemented with steam-rolled corn at 0.5% body weight (BWT). Calves were ultrasounded on day 0, day 43, and day 86 of the study to evaluate intramuscular fat deposition and backfat thickness. An longissimus muscle (LM) biopsy was taken on day 0 and day 86 of the study to evaluate gene expression. Supplemented steers tended (P < 0.10) to have more backfat than non-supplemented steers. Intramuscular fat amount differed (P < 0.05) by breed, while ribeye area tended (P < 0.10) to differ by breed. Wagyu exhibited a greater (P < 0.05) amount of intramuscular fat at the beginning and at the end of the study. Breed did not (P > 0.05) influence backfat thickness. Neither breed nor supplementation affected (P > 0.05) average daily gain or final body weights. Platelet-derived growth factor alpha (PDGRFA) and SREBP cleavage-activating protein (SCAP) differed (P < 0.05) between biopsy phases. Fatty acid binding protein-4 (FABP4) and stearoyl-coA desaturase-1 (SCD1) did not differ (P > 0.05) between breed or biopsy phase. In conclusion, changes in gene expression could indicate enhanced preadipocyte proliferation during this stage of calf development. Overall, supplementation altered backfat deposition but did not alter intramuscular fat levels. Opposingly, sire breed influenced intramuscular fat levels at an early age. A deeper understanding of the physical and molecular effects of supplementation and sire breed could provide additional avenues for manipulating adipose tissue.

Evidence that enforced sunlight exposure can cause hyperthermia in cattle ingesting low levels of ergot of rye (Claviceps purpurea), when air temperature and humidity conditions are only moderate.

To determine the rectal temperature response of cattle, following the oral administration of ergot of rye (Claviceps purpurea), under pen conditions of enforced sunlight compared with those of enforced shade. Hereford cross steers were divided into two groups of 18. One group was dosed once, on a Monday morning, with finely ground rye grass ergots at a rate of 180 mg/kg body weight and held in the sun for 7 h each day until Friday afternoon. The other group was not dosed but was similarly held in the sun during the same period. Their rectal temperatures were measured early morning and mid afternoon, from Monday to Friday inclusive. The process was repeated for each group, but this time they were held in the shade. The four treatment options were run concurrently by conducting the experiments over 6 weeks and using 3 animals in each treatment group, each week. The thermic response over all weeks, of the ergot treated, sunlight exposed cattle, was deemed greater than for the other groups, based on the following four parameters. The increase in rectal temperature between early morning and mid afternoon, the size of the mid afternoon rectal temperature rise, the difference between the maximum mid afternoon rectal temperature recorded by an animal in the sun compared with that recorded by the same animal in the shade, and finally the number of animals in a treatment group that recorded rectal temperatures > 40.00 degrees C. The difference in the daily increase in body temperature between the ergot treated, sun exposed cattle and the ergot treated, shaded cattle, was greater than that observed between the sun exposed and shade restricted control cattle. Nine of 18 ergot treated and sun exposed cattle developed hyperthermia; no cattle in the other three groups did. Some sunlight exposed cattle, dosed with a low amount of ergot of rye, can experience a body temperature elevation above the normal range, even under mild ambient temperature and humidity conditions. Sunlight exposure causes an increase in body temperature in normal cattle that is probably attributable to solar radiant heat. Ergot ingestion causes an increase in body temperature in shaded cattle that is probably attributable to ambient temperature and humidity effects. This response can be increased by sun exposure and this increase is attributable to solar radiant heat effects and possibly also solar radiation. A response to radiant heat is consistent with the known physiological effects of ingested ergot alkaloids, but a response to solar radiation is not.

Evaluation of the potential protein-sparing effects of sodium bicarbonate when added to grass silage for growing steers

Six Hereford-cross steers were used to determine whether or not the addition of sodium bicarbonate (NaHCO3) to grass silage (GS) would reduce the need for supplemental protein from fish meal (FM). Grass silage (31% DM; pH 4.8) was either unsupplemented or supplemented with FM (10% of silage DM); NaHCO3 was added at 0, 2, or 4% of silage DM. Supplementation with FM increased N retention (P < 0.01) but had no effects (P > 0.10) on feed intake or digestibility of organic matter (OM). Urinary N excretion decreased (P < 0.05) linearly with the addition of NaHCO3 but due to an increase in fecal N there was no significant effect (P > 0.10) of NaHCO3 on N balance. Urinary excretion of bicarbonate (HCO3) increased linearly (P < 0.01) with NaHCO3 addition, but there was no effect (P > 0.10) on urine pH or measures of blood acid-base status. Addition of NaHCO3 increased silage pH to 6.5 but had no effect (P > 0.10) on voluntary feed intake, or digestibility of OM and ADF. The results indicate that the addition of NaHCO3 to grass silage did not spare dietary protein but led to a shift in the partition of N between urine and feces. Key words: Steers, grass silage, sodium bicarbonate, nitrogen retention

Soy molasses as a feed ingredient for finishing cattle (1999)

Eighty Angus × Hereford cross steers were used in an individual feeding study to compare soybean molasses (a by-product of soybean meal manufacture) and soybean meal as ingredients in finishing diets containing flaked corn or a combination of high-moisture corn and dryrolled corn. Supplementation with soy molasses resulted in higher (P<.05) feed intakes in the cattle fed the high-moisture corn diet but had no effect on intakes of cattle fed the flaked diets. No such changes were noted for supplementation with soybean meal. In general, carcass traits were not influenced by level or type of supplement. Soy molasses appears to have feed value equal to or greater than that of soybean meal when compared on a protein basis. Its value as a source of supplemental nutrients appears to be greater in steam-flaked diets than in high-moisture diets.

Fatty acid profile of adipose tissue and performance of feedlot steers supplemented with dehulled cottonseed and sunflower seed meal protected from ruminal metabolism

The effect of feeding dehulled cottonseed protected from ruminal metabolism (PCS). Together with supplements of protected sunflower seed meal (PSM), on the performance and fatty acid profile of adipose tissue in feedlot steers was examined. Sixty-two Hereford cross steers, average weight 470 kg, were assigned to 4 groups and fed rations based on barley-corn silage for 150 days. The diets offered contained 10% untreated whole cottonseed +6% untreated sunflower seed meal (Group I), 10% PCS + 10% PSM (Group 11), 15% PCS + 10% PSM (Group 111), or 20% PCS + 10% PSM (Group IV). Inclusion of PCS at the level of 10, 15, and 20% together with 10% PSM resulted in an increase (P &lt; 0.01) in dressing percentage together with an improvement in feed conversion ratio. There was a 5-8-fold increase in the proportion of linoleic acid (C18: 2) in omental, perirenal, and subcutaneous fat from cattle fed the PCS supplement. A significant reduction occurred in the proportion of oleic acid (C18: 1 cis), but the percentage of palmitic acid (C16: 0) was not affected; the proportion of stearic acid (C18 : 0) in subcutaneous fat increased with PCS supplementation.

Interactions between beef cattle and simulated tuberculous possums on pasture

Brushtail possums (Trichosurus vulpecula) were sedated with ketamine and placed within a fenced observation area with 17 Hereford cross steers. The behaviour of the sedated possums simulated that of terminally ill possums. Behavioural analysis was carried out during eight observation periods in which sedated possums were successfully released and interactions occurred. Cattle were attracted from over 50 m away by the movements of the possums, and for 34% of observation time cattle investigated the possums. Inactive animals engendered far less interest, and cattle investigated them for 3% of observation time. An average of seven to eight cattle came in physical contact with the possum in each of the observation periods. Cattle actively investigated the possum while following it as it moved, commonly close enough to be within aerosol transmission distance, and some sniffed the possum, touched it with their noses, and in many cases licked it extensively. All of these activities would expose the cattle to high risk of receiving an infective dose of Mycobacterium bovis, especially via the respiratory route. The type and duration of contact between individual steers and the possum varied between animals and observation period. The cattle exposed themselves to greater risk, overall, during the first week of observations, and there was evidence of habituation with increased contact. Although all 17 steers came within 5 metres of the possum at some point during the observation periods, some individual cattle behaved in ways which would put them at greater risk of contracting tuberculosis than did others. Cattle showed little interest in possum carcasses placed on pasture. These were unlikely to be a significant source of infection for cattle, although they could be for scavenger species.

A comparison of fatty acid profiles and carcass characteristics of feedlot steers fed canola seed and sunflower seed meal supplements protected from metabolism in the rumen

The effect of feeding protected canola seed (PCS) and protected sunflower seed meal (PSM) supplements on the fatty acid profile and carcass characteristics of feedlot steers was examined. Fifty Hereford cross steers, average weight of 290 kg, were assigned to five groups of 10 and fed the following barley based concentrate rations for 133 days: I, control (containing 15% untreated sunflower seed meal (SSM)); 11, PSM 15%; 111, PCS 10%; IV, PSM 15% plus PCS 10%; V, PSM 15% plus PCS 15%. The inclusion of PCS, with and without PSM, increased the proportion of Cis unsaturated fatty acids in the subcutaneous, perirenal and omental fats; there were threefold increases in the proportion of linoleic (18: 2) acid, fivefold increases in linolenic (18 : 3) acid and smaller increases in the proportion of oleic acid (18 : 1). There was a 20-25% reduction in the proportion of palmitic acid, and the largest decrease was observed in the adipose tissue of steers receiving 15% PCS in the diet. Joint feeding of PCS and PSM significantly increased the dressing percentage of carcasses in Groups IV and V and fat depth in Group IV.

Growth and carcass characteristics of crossbred steers out of Jersey cows

Abstract Steers out of Jersey cows and sired by either Simmental (n = 25), Limousin (n = 27), Murray Grey (n = 30), or Hereford (n = 28) bulls were grazed together from an age of about 12 weeks until slaughter at about 29 months in two trials commencing in sequential years. Simmental-cross steers grew faster than Murray Grey-cross steers in both trials and faster than Limousin-cross steers in one trial. Limousin-cross steers grew faster than Murray Grey-cross and Hereford-cross steers in the first trial, but not in the other. Carcasses of the four sire-breed groups did not differ in fat colour, but pH of the longissimus muscle was higher for carcasses from Simmental and Limousin-cross animals in one trial. Carcasses of the later-maturing Simmental- and Limousin-cross cattle were longer, had less fat, and had heavier hindquarter cuts after adjustment to a common carcass weight. Heavier hindquarter cuts were also obtained from Limousincross carcasses than from Simmental-cross carcasses of the same weight. W...

A note on the effect of variety, type of straw and ammonia treatment on digestibility and on growth rate in steers

Forty Hereford cross steers of 350 kg live weight were allocated to 10 treatments in which straw was offered ad libitum. The straws comprised two varieties of winter barley (Gerbel (G) an Igri (I)), two varieties of spring barley (Corgi (C) and Golden Promise (GP)) and one variety of winter wheat (Norman (N)). Each straw was offered either untreated (with 20 g urea per kg added at feeding), or treated (with 30 g anhydrous ammonia). After 10 weeks the treatments were changed. The mean growth rates for steers receiving the untreated straws were 0·11, 0·13, 0·40, 0·20 and 0·27 kg/day and for treated straws were 0·36, 0·33, 0·61, 0·60 and 0·52 kg/day for G, I, C, GP and N respectively. The straw intakes for untreated straws were 3·4, 3·6, 5·2, 4·4 and 4·6 kg dry matter per day and for treated straws 4·7, 4·8, 5·9, 4·9 and 5·8 kg dry matter per day for G, I, C, GP and N respectively. Chemical and biological measurements were compared as predictors of voluntary intake of straw and growth rate in the steers. Biological measurements were very efficient in predicting performance of the steers while chemical measurements were much less valuable.

Effects of Dietary Additives on B-Vitamin Production and Absorption in Steers

Eight Hereford-cross steers (470 kg), each with T cannulae in the duodenum and ileum, were used in four trials to measure effects of monensin and chlortetracycline on thiamin, niacin, riboflavin and biotin production and absorption. Steers were fed at 2-h intervals and Cr-EDTA and acid-insoluble ash were used as markers. Diets were fed in pelleted form. Effects of monensin were tested (trial 1) using a diet that contained 90% corn + 22 mg monensin/kg feed. Feed, duodenal and ileal quantities of thiamin in steers fed the basal diet were 12.6, 7.4 and .8 mg/d, respectively. Steers fed the monensin diet had thiamin quantities of 14.0, 9.3 and 1.7 mg/d for the three sites. Dietary niacin quantities did not differ among diets; however, duodenal, ileal and fecal quantities of niacin were lower in monensin-fed animals. Riboflavin and biotin quantities were not affected by monensin supplementation. Apparent ruminal organic matter digestibility was lower for steers fed monensin. In trial 2, chlortetracycline (7.8 mg/kg diet) did not affect quantities of duodenal or ileal thiamin. Chlortetracycline tended to reduce flow of niacin to the duodenum. Duodenal or ileal riboflavin was not affected by feeding chlortetracycline. In trial 3, chlortetracycline (70 mg·head−1 ·d−1) did not affect duodenal quantities of thiamin, but increased ileal (P<.01) and fecal (P<.10) quantities of thiamin. Chlortetracycline did not affect quantities of duodenal or ileal niacin or riboflavin. Quantities of riboflavin were greater in feces of control steers than in steers fed chlortetracycline. In trial 4, effects of feeding chlortetracycline (1 g/d) for 3 d were investigated during the post-antibiotic feeding period. Samples were collected on d 1 and 2, 5 and 6, and 9 and 10 following withdrawal of chlortetracycline feeding (samples from adjacent days were pooled). Chlortetracycline resulted in increased quantities (P<.005) of duodenal thiamin during d 1 and 2 (13.7 vs 6.7 mg/d). This effect decreased with time. Chlortetracycline tended (P<.25) to decrease duodenal, ileal and fecal riboflavin throughout the collection period. Niacin and biotin quantities at the various sites were not greatly affected by feeding chlortetracycline in this manner.

Effect of restricted access to water, hay or salt on liveweights of steers

Fifty Hereford and Hereford cross steers (574 � 1.9 kg mean � s.e. initial liveweight) were purchased at a saleyard and given varying access to water, hay and salt for 46 h, to examine the effect of simulated on-farm treatments, prior to transport to a saleyard, on liveweight differences before and after access to water at the saleyard. Restricting access to feed or water reduced liveweight, the major effect being due to availability of water. Groups with hay only, or no feed or water, had similar liveweights, but were 29 kg lighter (P&lt;0.05) at the end of this period than steers with access to water, water and hay, or water, hay and salt. All steers lost weight when denied access to feed and water for 5 h to simulate the transport and yarding phase of the marketing process. The range in mean liveweights of the different groups was reduced from 36.5 kg at the start of this period to 29.5 kg at the end. All steers were then given ad libitum access to water for 15 h. They gained liveweight during first 2 h on water and thereafter lost weight. The extent of these gains was influenced by the magnitude of earlier weight losses. Access to water for 4 h was sufficient to reduce variation in mean liveweight between groups from 29.5 kg to 19.6 kg; this occurred mainly during the first hour. A further reduction to 14.0 kg occurred after 15 h of access to water. Consideration should be given to providing access to water before weighing at those cattle liveweight auctions which presently impose a fast from feed and water.

A COMPARISON OF THE GROWTH AND CARCASS CHARACTERISTICS OF STEERS REARED ON PASTURE AND FINISHED FOR VARYING PERIODS ON CORN OR GRASS SILAGE

Sixty small-framed yearling Hereford and Hereford cross steers initially averaging 268 kg were reared on pasture from May to October, divided into two (30 each) approximately equal weight groups and placed in a feedlot. The steers were serially slaughtered in groups of 10 (five heaviest from each treatment) after 0, 35, 70, 98, 126 or 154 days of feedlot finishing on either grass or corn silage supplemented with 0.9–2.3 kg-head−1∙day−1 of a mixed grain ration containing 5% molasses. Average gains on pasture were 0.80, 0.75 and 0.54 kg/day for the consecutive 59, 48 and 61 day periods between 9 May and 24 Oct. Steers finished on corn silage gained significantly faster (P &lt; 0.05) and had significantly more dissectable rib fat when slaughtered (0.82 kg/day; 27.6%) than steers finished on grass silage (0.51 kg/day; 24.6%). Six of the 10 steers slaughtered off pasture graded B1 or C1 while one of the feedlot steers graded B1 and the remaining 53 graded A1 or A2. The subjective carcass fat color score of the steers slaughtered off pasture averaged 4.7 which was significantly greater than the fat color of the feedlot finished steers (3.0–3.6). The corn silage steers had a color rating of 3.4 while the grass silage steers rated 3.7. The results of this experiment indicate that yearling steers reared on pasture and finished between 35 and 70 days on grass or corn silage with low concentrate supplementation will produce acceptable carcasses in terms of grade and subjective fat color score. Key words: Growth, carcass characteristics, steers, pasture, silage

Effect of animal size on the response in the performance of beef cattle to an improvement in silage quality

ABSTRACTTwo experiments have been carried out to examine the interaction between animal size and the response in animal performance to an increase in the digestibility of grass silage. In experiment 1, grass silages harvested during July and August after regrowth intervals of 43 and 85 days were offered ad libitum both unsupplemented and supplemented with 2 kg of concentrates per head per day to British Friesian steers of (±s.e.) 170±1·9, 300±2·9 and 420±3·6 kg initial live weight. Earlier cutting did not affect silage dry-matter intake or live-weight gain but increased carcass gain by 0·12kg/day (P&lt;0·01).In experiment 2, early-cut grass silage, made from two regrowths of perennial ryegrass, which were harvested during July and August after regrowth intervals of 43 and 48 days, and late-cut silage, made from a single regrowth, which was harvested in August after a regrowth interval of 90 days, were offered ad libitum to 84 Hereford-cross steers of (±s.e.) 170±3·4, 300±4·4 and 420±5|·2kg initial live weight. Earlier cutting increased silage dry-matter intake by 340 g/kg, live-weight gain by 0·23 kg/day and carcass gain by 0·18 kg/day (P&lt;0·001). It i s concluded that increasing the digestibility of grass silage by cutting grass at an earlier stage of growth is likely to produce a substantial increase in the daily carcass gain of beef cattle and that the response to higher digestibility is as great with mature cattle as with young, growing animals.

A note on the effect of limestone supplementation on the performance of cattle given barley-based diets

ABSTRACTGroups of Hereford-cross steers weighing 283 kg were given 0·6 kg dry matter hay per head per day, and bruised barley supplemented with 40 g of a fully soluble liquid product per kg, containing urea, minerals and vitamins,ad libitum. Half the animals received 10 g limestone per kg diet as an additional supplement. Over a 105-day period the food intake of the limestone-supplemented animals was 0·20 higher than that of unsupplemented animals. The resultant daily live-weight gain was 1·22 kg compared with 0·92 kg for the animals receiving the diet containing no additional limestone. Food conversion ratios (kg/kg live-weight gain) were improved by limestone supplementation from 6·84 to 6·19. Limestone inclusion did not appear to influence the low concentrations of starch (ca. 15 g/kg) present in the faecal dry matter but there was a small significant difference in faecal pH.

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.

Utilization of alkali-treated grain. 2. Utilization by steers of diets based on hay or straw and mixed with either NaOH-treated or rolled barley

In the first of three experiments, Hereford cross steers were fed ad libitum from 325 kg to slaughter at 425 kg on diets containing 50% hay and 50% rolled or NaOH-treated (30 g/kg) barley. Liveweight gain and food conversion ratios were similar for the two groups (1.24 vs. 1.42 kg/day; 7.0 vs. 7.0 kg dry matter intake/kg gain, respectively). Dry matter and organic matter digestibility was significantly higher ( P < 0.01) when the diet contained rolled, rather than NaOH-treated, barley. There were no significant differences in fibre digestibility (51.2 vs. 59.1%, respectively). In the second experiment, the optimum level of NaOH was determined for the treatment of barley when given with hay. The level of NaOH required to achieve a digestibility in whole barley similar to rolled barley was 40 g NaOH/kg, i.e., approximately 10 g/kg more than when NaOH-treated barley formed the sole component of the diet. Dry matter and organic matter digestibility increased linearly as the level of NaOH applied increased ( P < 0.05) and tended to peak at 40 g NaOH/kg barley. Starch digestibility also increased linearly ( P < 0.001). Fibre digestibility did not vary significantly between treatments. In the third experiment, the voluntary intake of straw by steers given rolled or NaOH-treated barley at two levels of supplementation was determined. The intake of straw was slightly, but not significantly, greater when NaOH-treated rather than rolled barley was used. The digestibility of dry matter, organic matter, starch and fibre was not significantly affected by method of cereal treatment. No problems of animal health arose throughout the three experiments.

Utilization of alkali-treated grain. 3. Utilization by steers of NaOH-treated and rolled barley in silage-based diets

In the first of three experiments, silage constituted 33 or 66% of the dry matter of complete diets, barley being the other component. The barley was either rolled, or treated with 30 g NaOH/kg dry matter. In two further treatments, the NaOH-treated barley was given in separate feeds, while silage was offered ad libitum. The diets were offered ad libitum to 32 Hereford cross steers from 325 kg live weight to slaughter at 450 kg live weight. Growth rate increased and feed conversion ratio decreased as the precentage of barley in the diet increased, but were significantly poorer with NaOH-treated than with rolled barley owing to the significantly lower digestibility of dry matter, organic matter and starch in diets containing NaOH-treated grain. In the second experiment, the effect on digestibility of increasing the NaOH added to the barley used in the mixed diets was investigated with steers. The results showed that the level of NaOH application had to be greater when NaOH-treated barley was used in mixed feeds than when it was used as the sole feed. The optimum rate of application in silage based diets was in the region of 45 g NaOH/kg dry matter. In the third experiment, forty Hereford cross steers were allocated to one of four treatments and were fattened from 325 to about 450 kg live weight. They were given (dry matter basis) 50% silage and 50% of barley, either rolled (RM) or treated with 45 g/kg NaOH (CM), mixed together, or they were given the silage alone until they had eaten the allocated quantity and then the allocated barley; the barley was either rolled (RS) or treated with 30 g/kg of NaOH (CS). The same quantities of silage and grain were given to all steers. The steers fed on silage and grain separately took, on average, 125 days to consume the feed (70 days for consumption of silage), but had similar carcass weights to the steers given mixed diets, which consumed their feed in 91 days. The growth rates for treatments RM, CM, RS and CS, respectively, were 1.15, 1.20, 0.89 and 0.78 kg/day, the food consumption was 737, 741, 728 and 741 kg dry matter and the final carcass weights were 256, 253, 247 and 252 kg. There were no significant differences between steers receiving the diets containing rolled or NaOH-treated barley.