Feed requirements for maintenance and growth of one-year-old Angus steers selected for either fast or slow yearling growth rate

1991 ◽  
Vol 31 (5) ◽  
pp. 591 ◽  
Author(s):  
RM Herd ◽  
PA Speck ◽  
PC Wynn

The efficiency of feed utilisation for maintenance and growth at 1 year of age was examined in 11 steers from each of 2 lines of Angus cattle selected for either fast (high line) or slow (low line) average daily gain to 1 year of age. The steers were established on a range of dietary energy intakes for 2 trials, each of 3 weeks duration. Fasted liveweights (LW) were measured at the start and end of each trial. Body fat was estimated at the end of the first trial. At the start of the experiment the high line steers were heavier (P<0.001) than the low line steers (278 v. 203 kg). The high line steers required more (P<0.001) feed per day [48.0 v. 39.3 MJ metabolisable energy (ME)] to maintain their greater LW but required less (P = 0.05) feed to sustain each kilogram of this LW (0.174 v. 0.192 MJ ME/kg LW) and, so, were more efficient. There was no difference in the efficiency of feed use for gain in LW (0.042 v. 0.040 kg LW/MJ ME.day). However, after adjusting feed intakes for the different mature sizes (A) of the 2 lines, there was no difference in the biological efficiency of feed use for either maintenance (0.369 v. 0.359 MJ ME/kg A0.73) or gain (5.45 v. 4.37 kg LW/MJ ME.kg A0.73). These results suggest that divergent selection for growth rate in this study has produced different-sized animals whose ability to convert feed to gain in LW has not been altered.


1990 ◽  
Vol 51 (3) ◽  
pp. 505-513 ◽  
Author(s):  
R. M. Herd

ABSTRACTA crossmothering experiment was conducted to measure the direct and the maternal components of the response to divergent selection for yearling growth rate in beef cattle. The animals were from three closed lines of Angus cattle. Two lines had been selected since 1974 for either high (high-line) or low (low-line) average daily gain from birth to yearling, and the third line was maintained as a randomly bred control-line. A total of 221 female calves born between 1984 and 1987 was used in the crossmothering experiment, and an additional 113 cows bearing calves in 1988 were used to obtain more records of milk production.On average, high-line calves born in 1984-87 were 45 kg heavier at weaning (200 days of age) than low-line calves and 65 kg heavier at yearling age, corresponding to a proportional divergence in daily weight gain of 0·29 and 0·32 respectively. The direct component of the response to selection was 0·82 (s.e. 0-05) of the divergence in body weight at weaning and 0·89 (s.e. 0·05) at yearling age. The maternal component was 0·18 (s.e. 0·06) and 0·11 (s.e. 0·04) for weaning and yearling weight respectively. Over the years 1984-88, high-line dams produced 1·15 times the milk of low-line dams and only 1·03 times that of control-line dams. There were small differences in the composition of milk sampled in 1984 which resulted in the milk of high-line dams having a higher content of metabolizable energy (ME) than that of control-line dams. The ME in the milk consumed by the calves from the three selection lines was sufficient to fuel similar proportions of their pre-weaning growth and indicated that the expression of the maternal component of the selection response may be via small differences in the quantity and quality of the milk produced by the dams. Expression of the direct component appeared to be at least partially via differences in appetite of the calves. These results, together with results for sheep, mice and rats, show that the direct component of the response to selection for growth is much larger than the maternal component.



2000 ◽  
Vol 51 (7) ◽  
pp. 833 ◽  
Author(s):  
Nguyen Hong Nguyen ◽  
Cam P. McPhee ◽  
Claire M. Wade ◽  
Brian G. Luxford

Genetic parameters for performance traits in a pig population were estimated using a multi-trait derivative-free REML algorithm. The 2590 total data included 922 restrictively fed male and 1668 ad libitum fed female records. Estimates of heritability (standard error in parentheses) were 0.25 (0.03), 0.15 (0.03), and 0.30 (0.05) for lifetime daily gain, test daily gain, and P2-fat depth in males, respectively; and 0.27 (0.04) and 0.38 (0.05) for average daily gain and P2-fat depth in females, respectively. The genetic correlation between P2-fat depth and test daily gain in males was –0.17 (0.06) and between P2-fat and lifetime average daily gain in females 0.44 (0.09). Genetic correlations between sexes were 0.71 (0.11) for average daily gain and –0.30 (0.10) for P2-fat depth. Genetic response per standard deviation of selection on an index combining all traits was predicted at $AU120 per sow per year. Responses in daily gain and backfat were expected to be higher when using only male selection than when using only female selection. Selection for growth rate in males will improve growth rate and carcass leanness simultaneously.



1975 ◽  
Vol 26 (6) ◽  
pp. 1093 ◽  
Author(s):  
GW Seifert

The response to one generation of selection for weight per day of age at 18 months (W/Af), in Africander cross (AX) and Brahman cross (BX) cattle, was evaluated in the female offspring of the up and down selected parents. The high W/A< line gained significantly more than the low line over a year from weaning. The advantage of the high W/A line occurred during flush nutritional periods. The realized heritability (h2) of W/Af at 18 months was 0.52, while the estimates of h2 from mid-parental means computed within sires was higher. Heritability estimates for birth weight (Wb), weaning weight per day of age (W/Aw), pre-weaning average daily gain (Gbw) and total average daily gain from birth to final weight (Gt) were all high, while the estimate for post-weaning average daily gain from weaning to final weight (Gpw) was low. The correlated responses of all the traits were high. The genetic correlations estimated from the response and the parent-offspring regressions were all positive and high. Birth weight was the most highly correlated with Gt. All phenotypic correlations were positive but lower than the genetic correlations, the correlation between Gbw and Gpw being the lowest. Environmental correlations between birth weight and pre-weaning traits were essentially zero, and between birth weight and post-weaning traits and Gt, negative. Weight per day of age at 18 months appeared to be the most efficient and practical single trait to select beef cattle for increased growth rate.



2021 ◽  
Vol 37 ◽  
pp. 00040
Author(s):  
Alexandr Donetskikh ◽  
Styapas Grikshas ◽  
Olga Pastukh ◽  
Polina Korenevskaya ◽  
Ruslan Kertiev

The article provides data on the weight growth of bulls of different types of productivity. The growth and development of Black-and-white, Simmental and Aberdeen-Angus bulls were studied during the period of their rearing and feeding. The change in live weight was established, the dynamics and growth rate of the studied bulls were calculated depending on the breed and type of productivity. The research results showed that the Aberdeen-Angus bulls had the highest live weight during fattening - 485.2 kg, which was significantly higher than that of the Black-and-White and Simmental breeds by 68.7 kg (p <0.001) or 14.0% and 19.7 kg (p <0.01), or 4.1% respectively. The average daily gain in live weight from birth to 15 months of age in bulls of Black-and-white, Simmental and Aberdeen Angus breeds amounted to 860.0; 965.1 and 1022.7 grams respectively. In the Aberdeen-Angus cattle, in comparison with the Black-and- White and Simmental breeds, the value of this indicator was significantly higher, by 162.7 g, or 15.9% (p <0.001) and 57,6 g, or 5.6% (p <0.01) respectively. It was found that the type of productivity had a certain effect on the dynamics of live weight, the intensity of growth and development of animals.



1969 ◽  
Vol 91 (3-4) ◽  
pp. 169-182
Author(s):  
Gisele Alexandre ◽  
Gilles Aumont ◽  
Ode Coppry ◽  
Jérome Fleury ◽  
Hary Archimede

The effect of age of regrowth (AR) of pasture herbage on milk production of Creole goats and growth rate of their kids while grazing irrigated Digitaria decumbens pastures was studied in Guadeloupe. Eighty-four does were used in an experiment to compare two rotational grazing systems over a one-year period during three kidding seasons classified as rainy, dry and intermediate. System AR21 allowed seven days of grazing and 21 days of regrowth whereas system AR35 allowed seven days and 35 days, respectively. An annual average stocking rate of 1,800 kg live-weight /ha was maintained in both systems. Dry matter (DM) yields were higher (P < 0.01) in the AR35 than in the AR21 system over the three seasons (4,935 vs. 2,948 kg/ha). Total biomass in the paddocks at the start of each grazing cycle varied between 11 and 19 DM kg/animal, depending significantly (P < 0.01) on the season. Age of regrowth had no effect. Daily milk production (938 to 1,033 g) also varied with the season but did not differ according to AR. Average daily gain (ADG) of kids in the AR21 system was lower by 23% than that of kids under the AR35. These differences were greater when ADG was adjusted for birth weight and milk production of the dam. Results may have been complicated by differences in gastro-intestinal parasitism, but this experiment showed that lowering AR of Digitaria decumbens pastures managed under intensive conditions did not significantly improve animal performance.



1990 ◽  
Vol 70 (3) ◽  
pp. 973-977 ◽  
Author(s):  
R. M. McKAY

Selection resulted in a decrease in probed backfat thickness and a negligible change in postweaning average daily gain. Realized heritabilities in the Yorkshire and Hampshire select lines were 0.41 ± 0.04 and 0.34 ± 0.18, respectively, for probed backfat thickness and 0.38 ± 0.43 and 0.65 ± 0.19, respectively, for postweaning average daily gain. Key words: Swine, selection differential, selection response, backfat, growth rate



2019 ◽  
Vol 3 (2) ◽  
Author(s):  
T. R. Krause ◽  
E. R. Moore ◽  
J. Duggin ◽  
J. R. Segers ◽  
T. D. Pringle

ObjectivesProfitability in the beef industry has narrow margins regulated by revenue from output traits like growth and carcass merit, but profitability is also largely impacted by input expenses like feed costs. Selecting for improvements in feed efficiency during the finishing phase, one of the most feed intensive segments of the industry, can help to mitigate those input costs. This study compared growth performance, feed efficiency, body composition, and carcass characteristics in Angus steers (n = 321) from bulls divergently selected for feed efficiency and marbling.Materials and MethodsAngus sires were selected based on high (10th percentile or better) and low (85th percentile or worse) residual average daily gain (RADG) EPD as well as high (fifth percentile or better) and average (near 50th percentile) marbling (MARB) EPD. These criteria resulted in a 2 × 2 factorial design with four breeding lines: high RADG/high MARB, high RADG/average MARB, low RADG/high MARB, low RADG/average MARB. Data were analyzed using MIXED procedures of SAS with RADG and MARB as main effects. Significance was set at α = 0.05. Generation was also analyzed, where generation one (GEN1) steers were from a selected sire while generation two (GEN2) steers were from a selected sire and a selected dam.ResultsUltrasound and carcass data revealed no differences (P ≥ 0.12) in 12th rib backfat thickness from weaning through slaughter for the RADG EPD groups. Yield grade and dressing percent did not differ (P ≥ 0.56) across RADG or MARB groups. At the beginning and end of the feeding trial, the high RADG (P ≤ 0.02) group had larger ultrasound ribeye area (REA) than the low RADG group. Carcass REA tended (P = 0.08) to be larger in the high versus low RADG steers. During the feedlot trial and through slaughter, body weight was heavier (P ≤ 0.006) for the high versus low RADG steers but did not differ (P ≥ 0.44) across MARB EPD. Feed efficiency measures did not differ (P ≥ 0.32) across RADG or MARB groups apart from the tendency (P = 0.08) for residual feed intake to be lower in the high versus low RADG steers. Marbling scores differed (P ≤ 0.04) across RADG and MARB groups with the low RADG steers and the high MARB steers having improved marbling. The quality grade distribution across MARB EPD revealed that the average MARB steers graded 73% Choice and 25% Prime while the high MARB steers graded 56% and 42%, respectively. Slice shear force did not differ (P ≥ 0.32) across RADG or MARB EPD. Body weights tended (P = 0.06) to be heavier at the start of the feeding trial for GEN1 versus GEN2 steers. Total gain, average daily gain, and feed to gain (F:G) differed by generation (P ≤ 0.007) with increased rates of gain and reduced F:G in the GEN2 versus GEN1 steers. Body weights did not differ (P = 0.72) across GEN at the end of the feeding trial. Backfat thickness at the start and end of the feedlot phase was less (P ≤ 0.03) and marbling score was improved (P = 0.02) in the GEN2 versus GEN1 steers, respectively.ConclusionThese results suggest that selection using RADG EPD has negligible impacts on meat quality; and that progress in selection for efficiency can be achieved while advancing carcass quality and value. Furthermore, continued divergent selection for feed efficiency and marbling has the potential to improve feed efficiency through advancements in the rate of gain, while enhancing carcass merit through marbling.



Author(s):  
G. A. Nozdrin ◽  
N. A. Gotovchikov ◽  
M. S. Yakovleva ◽  
N. S. Yakovleva ◽  
M. B. Lazareva

The combined effect of homobiotics, probiotics based on recombinant strains of g. Bacillus, & enrofloxacin on the dynamics of body weight gain in geese was studied. According to the principle of steam-analogs, one control and five experimental groups of 10 goslings in each group were formed. Gosyatam experimental groups used homobiotics vetom 15.1; vetom 13.1 incombination with enrofloxacin followed by replacement with a probiotic preparation Vetom 1.2. The absolute body weight and average daily gain in geese under the influence of the studied drugs increases. The severity of the effect depended on the pharmacological composition of the drugs used. The maximum absolute weight gain was observed when using the drugs according to the scheme: vetom 13.1 at doses of 25–50 mg/kg for 16 days, with further use of a 10% enrofloxacin solution at a dose of 0.5 ml/kg for 5 days and in The experiment period was 1.2 at a dose of 50 mg/kg for 16 days. After the cessation of the use of drugs, the growth rate increased for 30 days when prescribing the drugs according to the scheme: veto 13.1 at a dose of 50 mg/kg for 16 days and with further introduction of homobiotic veto 1.2 into the bird in a dose of 50 mg/kg for 16 days. The maximum average daily gain in live weight of geese was observed in the period from the 16th to the 32nd day with the administration scheme: homobiotic vetom 13.1 at a dose of 25 mg/kg of body weight 1 time per day for 5 consecutive days, then every other day for 16 days, then daily 10 % solution of enrofloxacin at a dose of 0.5 ml/kg of body weight for 5 days, then vetom 1.2 at a dose of 25 mg/kg once a day for 16 days in a row. And the maximum average daily gain in the post using period of the drug was observed on the 32nd day of the study according to the scheme: homobiotic veto 15.1 at a dose of 50 mg/kg of body weight 1 time per day for 16 days, then daily with vetom 1.2 at the same dose 1 once a day for 16 days. The studied drugs in the applied doses did not have a toxic effect on the physiological state of geese.



Author(s):  
А.И. БАХТУШКИНА ◽  
В.Р. САИТОВ ◽  
М.М. САЛЬНИКОВА

Проведено изучение интенсивности роста молодняка яков алтайской популяции, характеризующегося энергичным ростом. Динамика роста молодняка яков изучена путем определения их живой массы в разные возрастные периоды: при рождении, в возрасте 7, 12, 18 мес. По результатам взвешиваний определен абсолютный прирост, абсолютный среднесуточный прирост живой массы, относительная скорость роста. В период от рождения до 7-месячного возраста, который совпал с летним периодом пастбищного сезона, живая масса бычков увеличилась на 131,4 кг, а телок — на 120,2 кг. Интенсивность роста составила соответственно 625,7 и 572,4 г, что свидетельствует о достаточно хорошей молочности маток. В зимний период (возраст молодняка — от 7 до 12 мес) интенсивность роста резко снизилась: живая масса бычков и телочек составила всего 161,3 и 143,7 кг, со среднесуточными приростами — 94 и 58 г соответственно. С началом вегетации пастбищных растений приросты молодняка по сравнению с зимним периодом резко увеличились. В возрасте от 12 до 18 мес они были равны: 476 г — у бычков и 439 г — у телочек. Общий прирост живой массы бычков за этот период составил 86 кг, у телочек — 79 кг. Полученные данные свидетельствуют о достаточно хорошем развитии молодняка яков алтайской популяции. The growth rate of young yaks of the Altai population, characterized by vigorous growth, was investigated. The growth dynamics of young yaks was studied by determining their live weight at different age periods – at birth and at the age of 7, 12, 18 months. According to the weighing results, the absolute gain, the absolute average daily gain in live weight, and the relative growth rate were determined. In the period from birth to 7 months of age, which coincided with the summer months of the pasture season, the live weight of bull calves increased by 131.4, and heifers — by 120.2 kg, i.e., the growth rate was 625.7 and 572.4 g, respectively, which characterizes a fairly good milk yield of cows. In the winter period (age from 7 to 12 months), the growth rate decreased sharply: the live weight of calves and calves was only 161.3 kg and 143.7 kg, with average daily gains of 94 and 58g, respectively. Subsequently, with the beginning of the growing season of pasture plants, the weight gain of young animals in comparison with the winter period increased sharply. At the age of 12 to 18 months they were equal: 476 g-for steers and 439 g-for heifers. The total increase in live weight of calves during this period was 86 kg, of heifers — 79 kg. The data obtained indicate a fairly good development of young yaks of the Altai population.



Author(s):  
M.K. Curran ◽  
N.D. Cameron

To study responses to divergent selection for lean growth rate (LGA), lean food conversion ratio (LFC) and daily food intake (DFI), an experiment was started in 1984 at Edinburgh and Wye. This paper measured the selection pressure applied, the responses in the selection criteria and estimated the genetic and phenotypic relationships between the selection criteria with ad-libitum feeding of Landrace pigs after four generations of selection.The LGA (LFC) selection objective was to obtain equal correlated responses in growth rate (food conversion ratio) and carcass lean content, measured in phenotypic s.d. The LGA, LFC and DFI selection criteria had phenotypic s.d. of 32, 29 and 270 units and results are presented in s.d. units.Boars and gilts were purchased from eight British nucleus herds and boars from national artificial insemination centres in 1982. Homozygous or heterozygous halothane positive pigs were not included in the experiment. The base population consisted of 20 sires and 89 dams. Within each of the three selection groups, there were high and low selection lines with a control line, each consisting of 10 boars and 20 gilts, with a generation interval of one year. There were two control lines, one for LGA and one for LFC and DFI, as selection groups were arrowed continuously. The total number of pigs tested per line and average inbreeding coefficient at generation 4, within selection group are given below.



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