Metabolic differences in Angus steers divergently selected for residual feed intake

2004 ◽  
Vol 44 (5) ◽  
pp. 441 ◽  
Author(s):  
E. C. Richardson ◽  
R. M. Herd ◽  
J. A. Archer ◽  
P. F. Arthur
Keyword(s):  
Genetic Variation ◽  
Feed Intake ◽  
Aspartate Aminotransferase ◽  
Dry Matter ◽  
Residual Feed Intake ◽  
Breeding Values ◽  
Dry Matter Digestibility ◽  
Total Plasma Protein ◽  
Estimated Breeding Values ◽  
Animal House

Residual feed intake measures variation in feed intake independent of liveweight and liveweight gain. First generation steer progeny (n = 33) of parents previously selected for low or high post-weaning residual feed intake were examined to determine metabolic processes contributing to variation in residual feed intake. Blood samples were taken from the steers from weaning through to slaughter. These samples were analysed for key metabolites and hormones. Total urine and total faecal collections were taken from the steers in an animal-house experiment to estimate dry matter digestibility, microbial protein production and protein turnover. At weaning, there were phenotypic correlations between concentrations in plasma of β-hydroxy butyrate (r = 0.55, P<0.001), aspartate aminotransferase (r = 0.34; P<0.001), urea (r = 0.26, P<0.1) and total plasma protein (r = 0.26, P<0.1), and subsequent residual feed intake over the whole experiment (feedlot plus animal-house phases), but no evidence of associations with genetic variation in residual feed intake. At the start of the feedlot residual feed intake test period plasma levels of glucose, creatinine and aspartate aminotransferase were correlated with residual feed intake over the experiment (r = 0.40, –0.45 and 0.43, respectively, P<0.05), providing evidence of phenotypic associations with residual feed intake, and concentrations of urea and triglycerides were correlated with sire estimated breeding values for residual feed intake (b = 1.20 and –0.08, respectively, P<0.05), providing evidence for genetic associations with residual feed intake. At the end of the experiment, concentrations of plasma insulin, cortisol and leptin were correlated with residual feed intake over the experiment (r = 0.43, –0.40 and 0.31, respectively, P<0.05). Plasma concentrations of urea, insulin and cortisol illustrated trends for an association with sire estimated breeding values for RFI (b = –0.35, 0.98 and 12.19, respectively, P<0.1). The ratio of allantoin : creatinine in urine, as a measure of rumen microbial production, tended to be correlated with residual feed intake in the animal house (r�=�0.32, P<0.1) but not with residual feed intake over the entire experiment (r = 0.10, P>0.05). Neither the ratio of 3-methyl histidine : creatinine in urine, as a measure of rate of muscle breakdown, nor the dry matter digestibility measured in the animal house were correlated with residual feed intake in the animal house (r = 0.04, P>0.05), or residual feed intake over the whole experiment (r = –0.22, P>0.05), and neither were associated with genetic variation in residual feed intake.It is hypothesised that high-RFI (low-efficiency) steers have higher tissue energy requirements, are more susceptible to stress and utilise different tissue substrates (partly as a consequence of differences in body composition) to generate energy required in response to exposure to a stressful stimulus.

Divergent genotypes for fatness or residual feed intake in Angus cattle. 7. Low-fat and low-RFI cows produce more liveweight and better gross margins than do high-fat and high-RFI cows when managed under the same conditions

2018 ◽  
Vol 58 (1) ◽  
pp. 103
Author(s):  
L. Anderton ◽  
J. M. Accioly ◽  
K. J. Copping ◽  
M. P. B. Deland ◽  
M. L. Hebart ◽  
...  
Keyword(s):  
Feed Intake ◽  
Residual Feed Intake ◽  
Low Fat ◽  
Gross Margin ◽  
Breeding Values ◽  
Angus Cattle ◽  
Estimated Breeding Values ◽  
Supplementary Feed ◽  
Gross Margins ◽  
Stocking Rates

The present paper focuses on the economic evaluation of the observed differences in maternal productivity of different genetic lines in Angus cattle that were managed under contrasting nutritional regimes typical of southern Australia. Five hundred Angus cows were managed concurrently at two locations in southern Australia. On each site, the cows were managed under the following two different nutritional treatments: High and Low, to simulate different stocking rates. Cows selected for a divergence in either carcass rib-fat depth or residual feed intake based on mid-parent estimated breeding values for those traits, were allocated in replicate groups to either High- or Low-nutrition treatments. By design, the supplementary feeding regime was the same for the High and Low genetic lines to ensure genetic differences were not confounded with management differences. Animal productivity results from the experiment were used as input data to evaluate the economic performance of the four genetic lines under the two nutritional treatments. Two methods were used; the first was a gross-margin calculation of income minus variable costs as AU$ per breeding cow for a 1000-cow herd; the second was a whole-farm linear programming model maximising the gross margin. Stocking rates were optimised by matching the energy requirements for the whole herd with the energy available from pasture and supplementary feed on a representative 700-ha farm. Using the two methods of calculating gross margin (per cow and optimised per hectare), including examination of sensitivity to changes in prices of cattle and supplementary feed, the present study demonstrated that genetically leaner cows due to selection of low fat or low residual feed intake, had gross margins superior to those of genetically fatter cows. They generated more income by selling more liveweight due to heavier weights and higher stocking rates. The results are affected by the management system utilised and some confounding with growth (leaner genetic lines had higher growth estimated breeding values), but will assist producers to make more informed decisions about how to manage animal breeding and nutritional interactions.

Divergent breeding values for fatness or residual feed intake in Angus cattle. 6. Dam-line impacts on steer carcass compliance

2018 ◽  
Vol 58 (1) ◽  
pp. 94
Author(s):  
M. P. B. Deland ◽  
J. M. Accioly ◽  
K. J. Copping ◽  
J. F. Graham ◽  
S. J. Lee ◽  
...  
Keyword(s):  
Feed Intake ◽  
South Australia ◽  
Residual Feed Intake ◽  
Carcass Weight ◽  
Research Centre ◽  
High Fat ◽  
The South ◽  
Low Fat ◽  
Breeding Values ◽  
Estimated Breeding Values

The present study determined the impact of maternal genetics for estimated breeding values for rib fat (High-Fat, Low-Fat) or residual feed intake (RFI; High-RFI, Low-RFI) on the carcass compliance of Angus steer progeny when reared pre-weaning under High or Low-Nutrition and post-weaning under various finishing system (grazing versus short-term feedlot). The dams were joined to sires of similar genetic background (close to average estimated breeding values) and sires were rotated among all dam genotypes, with herds located at either Struan Research Centre, near Naracoorte in the south-east of South Australia, or Vasse Research Station, in the south-west of Western Australia. The breeding herd was part of the Beef CRC maternal productivity project and cows were managed under either High or Low-Nutrition, achieved by adjustments to stocking rate in rotational grazing systems and supplementary feeding, so as to maintain ~20% difference in cow liveweight. The steer progeny were weaned at ~7 months of age, with individuals from both pre-weaning nutritional treatments being treated the same from then on at each site. Steers from Struan Research Centre in South Australia born in 2008 and 2009 were sold and grown out on pasture on a local commercial property. Steer calves born in 2010 at Vasse remained on the station where they were backgrounded on hay, followed by a short period (111 days) total mixed ration containing 40% grain. In the first year, steers from Struan (n = 58) were slaughtered together at ~2 years of age, and in the second year (n = 85), consigned to six slaughter groups as their ultrasound-scanned subcutaneous P8 (rump) fat reached 7 mm and their liveweight exceeded 550 kg. Steers from Vasse (n = 101) were slaughtered at ~12 months of age, all on the same day. High-Fat-line dams produced steers with carcasses with greater P8 fat than did Low-Fat-line dams at both sites. At Struan, when the 2008-born steers were slaughtered together, more steers from Low-Fat dams failed to meet minimum fat specifications, than steers from High-Fat dams (28% vs 9% respectively). The steers born in 2009 at Struan all met processor fat specifications but steers from the Low-Fat dams took longer to reach the fat threshold, and so had greater carcass weight, but attracted more price penalties because of increased dentition. All steers from Vasse met minimum requirements for fat, with none penalised for dentition. Vasse steers from High- or Low-RFI dams performed in a manner similar to that from High- and Low-Fat dams, respectively, in that the High-RFI group produced fatter carcasses than did the Low-RFI group. Steers reared under low pre-weaning nutrition weighed less at weaning than did those on High-Nutrition, but had higher weight gains after weaning, although insufficient to result in the same carcass weight. The results showed that commercial cattle producers need to be aware of the balance and trade-off among fat breeding value, effect of pre-weaning nutrition and post-weaning growth required to ensure their cattle meet market specifications and to avoid price penalties.

Potential for selection to improve efficiency of feed use in beef cattle: a review

1999 ◽  
Vol 50 (2) ◽  
pp. 147 ◽  
Author(s):  
J. A. Archer ◽  
E. C. Richardson ◽  
R. M. Herd ◽  
P. F. Arthur
Keyword(s):  
Genetic Variation ◽  
Beef Cattle ◽  
Feed Intake ◽  
Production System ◽  
Feed Efficiency ◽  
Genetic Correlations ◽  
Total Production ◽  
Breeding Values ◽  
Improve Efficiency ◽  
Estimated Breeding Values

Evidence for genetic variation in feed efficiency of beef cattle is reviewed in this paper, and ways in which this variation might be used in selection programs to improve beef cattle in Australia are discussed. Efficiency of beef production systems is determined by feed and other inputs of all classes of animals in the production system as well as outputs in terms of slaughter progeny and cull cows. Different indices have been used to express aspects of efficiency on cattle over certain periods of the production cycle. Use of these indices is discussed, and then evidence for genetic variation in both growing animals and mature animals is reviewed. Genetic variation in feed efficiency exists in both growing and mature cattle, although information is lacking to determine whether variation in total production system efficiency exists. The physiological basis for observed variation in feed efficiency is discussed, with differences in requirements for maintenance, body composition, proportions of visceral organs, level of physical activity, and digestion efficiency identified as possible sources of variation. Selection to improve efficiency might be achieved by measuring feed intake of growing animals and utilising genetic correlations that are likely to exist between efficiency of growing animals and mature animals. Measurement of feed intake might occur in central test stations, or methods may be developed to measure feed intake on-farm. Ways of utilising information generated in genetic evaluations are discussed, and it is concluded that estimated breeding values for feed intake after a phenotypic adjustment for growth performance would be most practical, although not theoretically optimal. Such estimated breeding values would best be used in an economic selection index to account for genetic correlations with other traits, including feed intake of the breeding herd, and the economic value of feed in relation to other traits. Future research should be directed towards understanding the genetic relationships between feed intake and other traits in the breeding objective, and to find ways to reduce the cost of measurement of feed intake, including a search for genetic markers.

Genetic variation in starch digestion in feedlot cattle and its association with residual feed intake

2004 ◽  
Vol 44 (5) ◽  
pp. 469 ◽  
Author(s):  
A. F. Channon ◽  
J. B. Rowe ◽  
R. M. Herd
Keyword(s):  
Genetic Variation ◽  
Feed Intake ◽  
Dry Matter ◽  
High Efficiency ◽  
Residual Feed Intake ◽  
Matter Content ◽  
Dry Matter Content ◽  
Production Traits ◽  
Starch Digestion ◽  
Faecal Ph

Steer progeny of lines selected for either low residual feed intake (high efficiency) or high residual feed intake (low efficiency) were grown out in a feedlot and measurements of feed intake, liveweight gain and faecal parameters were combined to investigate associations with starch digestion. There were significant differences between sire progeny groups in faecal pH and faecal dry matter content indicating genetic differences in starch digestion. This variation occurred even after differences in dry matter intake were accounted for. Furthermore, there was a significant association between these faecal parameters and mid-parent Estimated Breeding Values for residual feed intake, rib (12/13th) fat depth and rump fat depth (Australian P8 site). This confirmed an association between parameters believed to describe starch digestion and genetic variation in important production traits. Low faecal pH and faecal dry matter content were associated with higher residual feed intake (i.e. lower efficiency).

scholarly journals Influence of Residual Feed Intake and Cow Age on Dry Matter Intake Post-Weaning and Peak Lactation of Black Angus Cows

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1822
Author(s):  
Cory T. Parsons ◽  
Julia M. Dafoe ◽  
Samuel A. Wyffels ◽  
Timothy DelCurto ◽  
Darrin L. Boss
Keyword(s):  
Milk Production ◽  
Feed Intake ◽  
Dry Matter ◽  
Free Choice ◽  
Residual Feed Intake ◽  
Beef Cows ◽  
Age Effect ◽  
Dry Matter Intake ◽  
Intake Rate ◽  
Two Stages

We evaluated heifer post-weaning residual feed intake (RFI) classification and cow age on dry matter intake (DMI) at two stages of production. Fifty-nine non-lactating, pregnant, (Study 1) and fifty-four lactating, non-pregnant (Study 2) commercial black Angus beef cows were grouped by age and RFI. Free-choice, hay pellets were fed in a GrowSafe feeding system. In Study 1, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect (p < 0.01) with an increase in DMI and intake rate with increasing cow age. In Study 2, cow DMI (kg/d) and intake rate (g/min) displayed a cow age effect (p < 0.02) with an increase in DMI and intake rate with increasing cow age. Milk production displayed a cow age × RFI interaction (p < 0.01) where both 5–6-year-old and 8–9-year-old low RFI cows produced more milk than high RFI cows. For both studies, intake and intake behavior were not influenced by RFI (p ≥ 0.16) or cow age × RFI interaction (p ≥ 0.21). In summary, heifer’s post-weaning RFI had minimal effects on beef cattle DMI or intake behavior, however, some differences were observed in milk production.

Daily methane emissions and emission intensity of grazing beef cattle genetically divergent for residual feed intake

2017 ◽  
Vol 57 (4) ◽  
pp. 627 ◽  
Author(s):  
J. I. Velazco ◽  
R. M. Herd ◽  
D. J. Cottle ◽  
R. S. Hegarty
Keyword(s):  
Feed Intake ◽  
Emission Intensity ◽  
Dry Matter ◽  
Average Daily Gain ◽  
Residual Feed Intake ◽  
Conversion Ratio ◽  
Feed Conversion Ratio ◽  
Breeding Value ◽  
Dry Matter Intake ◽  
Feed Conversion

As daily methane production (DMP; g CH4/day) is strongly correlated with dry matter intake (DMI), the breeding of cattle that require less feed to achieve a desired rate of average daily gain (ADG) by selection for a low residual feed intake (RFI) can be expected to reduce DMP and also emission intensity (EI; g CH4/kg ADG). An experiment was conducted to compare DMP and EI of Angus cattle genetically divergent for RFI and 400-day weight (400dWT). In a 6-week grazing study, 64 yearling-age cattle (30 steers, 34 heifers) were grazed on temperate pastures, with heifers and steers grazing separate paddocks. Liveweight (LW) was monitored weekly and DMP of individual cattle was measured by a GreenFeed emission monitoring unit in each paddock. Thirty-nine of the possible 64 animals had emission data recorded for 15 or more days, and only data for these animals were analysed. For these cattle, regression against their mid-parent estimated breeding value (EBV) for post-weaning RFI (RFI-EBV) showed that a lower RFI-EBV was associated with higher LW at the start of experiment. Predicted dry matter intake (pDMI), predicted DMP (pDMP) and measured DMP (mDMP) were all negatively correlated with RFI-EBV (P < 0.05), whereas ADG, EI, predicted CH4 yield (pMY; g CH4/kg DMI) were not correlated with RFI-EBV (P > 0.1). Daily CH4 production was positively correlated with animal LW and ADG (P < 0.05). The associations between ADG and its dependent traits EI and pMY and predicted feed conversion ratio (kg pDMI/kg ADG) were strongly negative (r = –0.82, –0.57 and –0.85, P < 0.001) implying that faster daily growth by cattle was accompanied by lower EI, MY and feed conversion ratio. These results show that cattle genetically divergent for RFI do not necessarily differ in ADG, EI or pMY on pasture and that, if heavier, cattle with lower RFI-EBV can actually have higher DMP while grazing moderate quality pastures.

scholarly journals Effect of Sulphate ion on the in Vitro Rumen Digestion of Polysaccharide Constituents of Bagasse

1972 ◽  
Vol 25 (6) ◽  
pp. 1377 ◽  
Author(s):  
RFH Dekker ◽  
GN Richards
Keyword(s):  
Feed Intake ◽  
Dry Matter ◽  
Poor Quality ◽  
Crude Fibre ◽  
Heteropogon Contortus ◽  
Dry Matter Digestibility ◽  
Inorganic Sulphate ◽  
Acid Detergent Fibre

The dry matter digestibility (DMD) of poor quality roughages such as spear grass (Heteropogon contortus) by sheep and cattle has been shown to increase on addition of sulphur to the diet. The sulphur is added most frequently as inorganic sulphate, either alone (Playne 1969) or supplemented with urea (Bray and Hemsley 1969; Kennedy and Siebert 1972; Siebert and Kennedy 1972) or gluten (Playne 1969). These supplements have also increased feed intake in sheep (Playne 1969; Kennedy and Siebert 1972; Siebert and Kennedy 1972) and cattle (Siebert and Kennedy 1972), and have improved the nitrogen and sulphur balance (Moir, Somers, and Bray 1967; Bray and Hemsley 1969; Playne 1969; Kennedy and Siebert 1972) within the animal. Sulphates have been shown to increase the in vitro rumen digestion of starch (Kennedy, Mitchell, and Little 1971), crude fibre (Bray and Hemsley 1969), and acid-detergent fibre and cellulose (Barton, Bull, and Hemken 1971).

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