Residual feed intake adjusted for backfat thickness and feeding frequency is independent of fertility in beef heifers

2011 ◽  
Vol 91 (4) ◽  
pp. 573-584 ◽  
Author(s):  
J. A. Basarab ◽  
M. G. Colazo ◽  
D. J. Ambrose ◽  
S. Novak ◽  
D. McCartney ◽  
...  

Basarab, J. A., Colazo, M. G., Ambrose, D. J., Novak, S., McCartney, D. and Baron, V. S. 2011. Residual feed intake adjusted for backfat thickness and feeding frequency is independent of fertility in beef heifers. Can. J. Anim. Sci. 91: 573–584. This study examined the effects of residual feed intake (RFI), RFI adjusted for off-test backfat thickness (RFIfat) and RFI adjusted for off-test backfat thickness and feeding event frequency (RFIfat & activity) on heifer fertility and productivity. Beef heifers (n=190) were monitored for individual daily feed intake and feeding event activity over 108–112 d using the GrowSafe System® and assessed for age at puberty based on plasma progesterone concentration. Individual animal daily feed intake, feeding event activity and off-test backfat thickness were then used to calculate RFI, RFIfat and RFIfat & activity and group heifers as either negative ([−], RFI<0.0) or positive ([+], RFI≥0.0) for RFI. Heifers averaged 298 kg (SD=34) in body weight, were 276 days of age (SD=19) at the start of test, grew at 0.90 kg d−1 (SD=0.21), consumed 7.62 kg DM head−1 d−1 (SD=0.84) and had a feed conversion ratio of 8.93 (SD=2.43). Age (351 d, SD=43) and weight (367.3 kg, SD=45.0) at puberty were similar between [−] and [+] RFI heifers, but age at puberty was delayed in [−] RFIfat (P=0.04) and RFIfat & activity (P=0.08) heifers compared with [+] RFIfat and RFIfat & activity heifers. Efficient or [−] RFI heifer exhibited a lower pregnancy (76.84 vs. 86.32%, P=0.09) and calving rate (72.63 vs. 84.21%, P=0.05) compared with [+] RFI heifers. These differences were partially removed in [−] RFIfat and completely removed in [−] RFIfat & activity compared with their [+] RFI counterparts (pregnancy rate, 80.85 vs. 82.29%, P=0.80; calving rate, 75.53 vs. 81.25%, P=0.34). No differences were observed between efficient and inefficient heifers in calving difficulty, average calving date, age at first calving, calf birth weight, calf pre-weaning ADG, calf weaning weight and heifer productivity. However, [+] RFI heifers exhibited a 1.9-fold higher calf death loss compared with [−] RFI heifers (11.11% vs. 5.71%, P=0.24). This difference was more pronounced in [+] RFIfat and [+] RFIfat & activity heifers, which exhibited 2.2-fold (11.84% vs. 5.33%, P=0.15) and 3.0-fold (12.66% vs. 4.17%, P=0.06) higher calf death loss compared with [−] RFI heifers. There was no relationship of RFI adjusted for backfat thickness and feeding activity on fertility traits indicating that backfat thickness and feeding activity may be associated with feed intake and should be considered when selecting heifers for improved feed efficiency.

2004 ◽  
Vol 84 (2) ◽  
pp. 177-185 ◽  
Author(s):  
F. S. Schenkel ◽  
S. P. Miller ◽  
J. W. Wilton

Genetic associations between feed efficiency, growth, and live ultrasound measured body composition traits were studied in purebred beef bulls of six breeds in Ontario bull test stations from 1991 to 2000. Feed traits included average daily feed intake (FI), feed conversion ratio (FCR), and residual feed intake [feed intake adjusted for production alone (RFIp) or production and backfat thickness (RFIb)]. Growth traits were average daily weight gain (ADG), mid-test metabolic weight (MW), hip height (HH), and scrotal circumference (SC). Body composition traits included ultrasound backfat thickness (BF), longissimus muscle area (LMA), and predicted percentage of intramuscular fat (IFAT). Bulls were measured every 28 d for weight and individual feed intake, and at the end of test for ultrasound body composition traits. Number of records per trait ranged from 2284 (FI) to 13 319 (ADG). Fixed effects of test group, breed and end of test age (within breed), and random effects of animal and herd of origin were modeled using REML bivariate analyses for all traits. Heritability estimates were moderate for all traits (0.30 to 0.55), except for IFAT (0.14). The genetic correlation between RFIp and RFIb was high (0.99) within breeds, but breeds ranked differently with respect to RFIp and RFIb. Genetic correlations of RFIb with ADG and backfat thickness were essentially zero, which indicate that selection on residual feed intake could be implemented to reduce feed intake and improve feed conversion without compromising growth or changing levels of subcutaneous fat. Key words: Central test, genetic correlation, heritability, residual feed intake


2015 ◽  
Vol 95 (3) ◽  
pp. 369-381 ◽  
Author(s):  
G. Manafiazar ◽  
J. A. Basarab ◽  
V. S. Baron ◽  
L. McKeown ◽  
R. R. Doce ◽  
...  

Manafiazar, G., Basarab, J. A., Baron, V. S., McKeown, L., Doce, R. R., Swift, M., Undi, M., Wittenberg, K. and Ominski, K. 2015. Effect of post-weaning residual feed intake classification on grazed grass intake and performance in pregnant beef heifers. Can. J. Anim. Sci. 95: 369–381. There is limited knowledge of how cattle tested for feed efficiency under drylot conditions perform when they graze on summer pasture. Residual feed intake adjusted for end of test backfat thickness (RFIfat) was determined on 171 beef crossbred heifers under drylot conditions over 2 yr using an automated system. Upon completion of the test, the 10 lowest and 10 highest RFIfat (–0.54±0.17 vs. 0.58±0.15 kg DM d−1) heifers in 2012, and the 14 lowest and 14 highest RFIfat (−0.47±0.16 vs. 0.53±0.19 kg DM d−1) heifers in 2013 were selected and placed on meadow bromegrass pasture to investigate the effect of RFIfat ranking on their grass intake and performance on the pasture. The pasture adaptation period (8 d in 2012 and 19 d in 2013) was followed by a pasture feed intake experiment during which heifers were dosed twice daily (0815 and 1415) with 500 g of C32-labeled feed pellet for 13 d (day 0 to 12) and fecal sampled twice daily (0815 and 1415) from day 8 to 12. Forage DM intake on pasture for each heifer was determined using the double alkane (C31/C32) methodology. High and low RFIfat heifers were similar in body weight (BW), backfat and rump fat thickness, and average daily gain (ADG) during the grazing trial period, except backfat thickness at the end of test period. However, low RFIfat heifers consumed 5.3% less forage when expressed as kg DM d−1 (8.20±0.08 vs. 8.66±0.09, P<0.001) and 5.1% less when expressed as a percentage of body weight (1.86±0.02 vs. 1.96±0.02% of BW, P<0.001) compared with high RFIfat heifers. RFIfat measured under drylot conditions in growing heifers was positively correlated to grazed RFIfat determined in pregnant heifers (rp=0.30, P=0.04). These results suggest that beef heifers classified as low RFIfat during the post-weaning drylot period had lower dry matter intake as heifers in their first pregnancy grazing tame pasture, with no negative impact on their body weight, back-fat thickness, and ADG compared with their high RFIfat herdmates.


2017 ◽  
Vol 57 (4) ◽  
pp. 627 ◽  
Author(s):  
J. I. Velazco ◽  
R. M. Herd ◽  
D. J. Cottle ◽  
R. S. Hegarty

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.


2011 ◽  
Vol 40 (4) ◽  
pp. 929-937 ◽  
Author(s):  
T. Lucila Sobrinho ◽  
R.H. Branco ◽  
S.F.M. Bonilha ◽  
A.M. Castilhos ◽  
L.A. Figueiredo ◽  
...  

The objective of this work was to evaluate performance, efficiency parameters and phenotypic correlations among measurements of energy efficiency of Nellore cattle selected for post weaning weight and classified according to residual feed intake, calculated by the difference between observed and predicted intake, based on average metabolic body weight and average daily gain. Thus, animals were classified within three groups: high (> mean + 0.5 standard deviation, less efficient); medium (±0.5 standard deviation of the mean); and low (< mean - 0.5 standard deviation, more efficient) residual feed intake. No differences were observed at initial and final body weights, average daily gain and dry matter intake among groups. Animals with low residual feed intake also had greater feed efficiency, feed conversion and partial efficiency of growth and did not differ from the other animals regarding to relative growth rate and Kleiber ratio. Residual feed intake was significantly correlated to feed efficiency (-0.25), feed conversion (0.25), partial efficiency of growth (-0.37) and dry matter intake (0.16) but it did not present significant correlation with body weight (0.04), average daily gain (-0.02), relative growth rate (-0.03) and Kleiber ratio (-0.05). Significant correlations were found between feed conversion and initial body weight (0.34) and average daily gain (-0.46). Partial efficiency of growth presented significant correlation with all other efficiency parameters analyzed. Residual feed intake has high potential in productive efficiency, when compared to the other energy efficiency measurements, being independent of growth and size of the animals.


2013 ◽  
Vol 14 (3) ◽  
pp. 527-537 ◽  
Author(s):  
Miguel Henrique de Almeida Santana ◽  
Paulo Rossi Junior ◽  
Rodrigo de Almeida ◽  
Amanda Massaneira de Souza Schuntzemberger

Due to the potential metabolic changes related to the residual feed intake (RFI), this study investigated the correlation of traditional RFI (RFI1), RFI adjusted for final rump fat thickness (RFI2) and feed conversion ratio (FCR) with the metabolic and blood profiles, as well as determined the possible different classes of RFI1 and RFI2. For this purpose, 46 Nellore bulls, 22 month-old and 411kg of weight at the beginning of the study were used. The animals were fed with the same diet for 84 days, and blood samples were collected every 21 days for evaluation of serum metabolites and blood cell profiles. No significant correlations were found between FCR and metabolic or blood traits, although there was a significant correlation between RFI1 and urea serum concentration. There were also differences between the RFI classes for creatinine, in which more efficient animals showed higher values. The RFI2 did not correlate with any metabolic and blood cell variable, but young bulls with smaller RFI2 had a smaller number of eosinophils when compared to animals with higher RFI2. These results suggest that animals with a high RFI can have greater energy expenditure due to protein synthesis and degradation process, resulting in a larger blood urea level.


1979 ◽  
Vol 59 (3) ◽  
pp. 577-583 ◽  
Author(s):  
R. NARENDRAN ◽  
G. H. BOWMAN ◽  
S. J. SLINGER

An experiment was conducted during the late fall and winter months with 96 Yorkshire barrows and gilts to study the effects on pig performance of feeding corn-soybean meal (SBM) and lysine-HCl (0.1%) supplemented corn-SBM-Tower rapeseed meal (RSM) and corn-SBM-Candle RSM diets, in the form of mash (corn was medium-ground) and steam pellets. Average daily gain (ADG), feed intake, efficiency of feed conversion (feed to gain ratio, F/G) and carcass backfat thickness were measured in pigs reared from 23 kg to 91 kg liveweight. The energy level in the RSM diets was not adjusted to equal that in the corn-SBM diet. Pigs fed Tower RSM had a lower (P < 0.01) feed intake and backfat thickness and pigs fed Candle RSM had a lower (P < 0.01) ADG and feed intake and higher (P < 0.01) F/G compared to the pigs fed SBM. The pigs fed corn-SBM-Tower RSM had a higher (P < 0.01) ADG and feed intake and lower (P < 0.01) F/G ratio than those fed Candle RSM diets. Steam pelleting of the corn-SBM and corn-SBM-RSM diets improved ADG, feed intake and F/G of the pigs, with the effects being greatest for the RSM diets.


1982 ◽  
Vol 98 (1) ◽  
pp. 23-29 ◽  
Author(s):  
B. J. W. Gartner ◽  
G. M. Murphy ◽  
W. A. Hoey

SUMMARYHereford heifers were fed a diet (7·0 MJ ME/kg D.M.) containing 0·09 % phosphorus but complete with regard to other nutrient constituents. Only after 19 weeks wore the effects of subclinical aphosphorosis evident in the form of reduction in feed intake, cessation of weight gain, increased feed conversion and decreases in tho concentration of inorganic phosphorus in blood and saliva. Heifers supplemented daily with 12 g phosphorus sustained a weight gain of about 0–2 kg/day over 62 weeks as did other supplemented heifers whose feed intake was restricted to that of tho low phosphorus treatment. The effects of phosphorus supplementation were thus demonstrated without being confounded by concomitant increases in feed intake.Phosphorus supplementation resulted in significantly lowered apparent crude protein digestibility and a slight increaso in cell wall digestibility.


2007 ◽  
Vol 87 (4) ◽  
pp. 489-502 ◽  
Author(s):  
J. A. Basarab ◽  
D. McCartney ◽  
E. K. Okine ◽  
V. S. Baron

Two hundred and twenty-two yearling calves and their dams were used to examine the phenotypic (rp) relationships between progeny residual feed intake (RFI) and maternal productivity across 10 production cycles. Progeny RFI ranged from -3.95 to +2.72 kg as fed d-1 (SD = 0.94), while RFI adjusted for off-test backfat thickness (RFIadj), ranged from -2.48 to +1.53 kg as fed d-1 (SD = 0.88). Progeny RFI and RFIadj were unrelated to on-test age, body weight, growth rate, and ultrasound longissimus thoracis area and positively related to feed intake (rp = 0.51 to 0.53; P < 0.001), feed to gain ratio (rp = 0.44 to 0.46; P < 0.001), feeding behaviour traits (rp = 0.29 to 0.36; P < 0.001) and cow RFI (rp = 0.30, P < 0.05). Progeny RFI was positively related to measures of body fat (rp = 0.21 to 0.27; P < 0.05), but these relationships disappeared when RFI was adjusted for off-test backfat thickness. Cows that had produced LOW (≤ 0.5 SD), MEDIUM (± 0.5 SD) or HIGH (≥ 0.5 SD) RFIadj progeny were similar in pregnancy (95.6 vs. 95.3 vs. 96.0%, P = 0.90), calving (84.9 vs. 83.4 vs. 86.3%, P = 0.62) and weaning (81.5 vs. 80.2 vs. 82.3%, P = 0.79) rates. However, cows that produced HIGH RFIadj progeny had a higher twinning rate (3.77 vs. 0.35 vs. 0.00%, P < 0.001) and an increased calf death loss (8.06 vs. 4.24 vs. 4.02%, P = 0.10) compared with cows that produced MEDIUM or LOW RFIadj progeny. Cow body weight over 10 production cycles was similar at weaning, pre-calving and pre-breeding for dams that had produced LOW, MEDIUM and HIGH RFIadj progeny, and dams that produced LOW RFIadj progeny consistently averaged 2–3 mm more back fat thickness than dams that produced HIGH RFIadj progeny. Calf birth weight, pre-weaning ADG and 200-d weight, and cow production efficiency and calving interval were similar among dams that produced LOW, MEDIUM and HIGH RFIadj progeny. In addition, dams that produced LOW RFIadj progeny consumed less feed during their second trimester of pregnancy (10.9 vs. 11.6 vs. 12.2 kg DM d-1, P < 0.05), had lower RFI values (-0.05 vs. 0.44 vs. 1.88 kg as fed d-1, P = 0.018) and calved later in the year (96 vs. 90 vs. 91 d Julian, P < 0.001) than dams that produced MEDIUM and HIGH RFIadj progeny. These results showed that efficient RFI progeny and dams consumed less feed, had improved feed to gain ratio and spent less time in feed activity than inefficient cows and calves. In addition, cows that produced efficient calves were fatter, had fewer twins, less calf death loss and produced the same weight of calf weaned per cow exposed to breeding compared with cows that produced inefficient progeny. However, cows that produced efficient or low RFI progeny calved 5–6 d later in the year than cows that produced inefficient or high RFI progeny, indicating a need to monitor reproductive fitness in low RFI replacement heifers and breeding bulls. Key words: Residual feed intake, cow reproduction, lifetime production efficiency


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