497 Effects of post-weaning plane of nutrition and estrus synchronization on reproductive performance of Bos indicus-influenced beef heifers

Abstract This study investigated growth and reproductive performance of Bos indicus-influenced beef heifers provided a concentrate supplement at either a constant or stair-step supplementation. Sixty-four Brangus heifers were stratified by initial BW and age (255 ± 20 kg; 270 ± 22 d) and assigned to 1 of 16 bahiagrass pastures (4 heifers/pasture). Treatments were randomly assigned to pastures (8 pastures/treatment) and consisted of concentrate DM supplementation at: (1) 1.50% of BW from d 0 to 100 (CON) and (2) 1.05% of BW from d 0 to 49 and 1.95% of BW from d 50 to 100 (STP). Supplementation started on d 0 and continued until start of estrous synchronization on d 100. Intravaginal temperatures (16 heifers/treatment) were collected every 30 minutes from d 25 to 31 (September) and d 85 to 91 (November). All heifers were provided supplement at 1.50% of BW from d 101 to 211. Heifers were bred by AI from d 113 to 115 and Brangus bulls were placed with heifers from d 121 to 211. Data were analyzed using the MIXED procedure of SAS with treatment, time, and interaction as fixed effects. From d 0 to 49, ADG did not differ (P = 0.87); however, STP heifers had greater (P = 0.01; 0.73 vs. 0.56 kg/d) ADG from d 50 to 100 compared to CON heifers. Percentage of pubertal heifers, percentage of heifers in estrus, or reproductive tract scores did not differ between treatments (P ≥ 0.40). Intravaginal temperatures were greater (P < 0.0001) for CON vs. STP heifers from d 25 to 31 but did not differ (P = 0.74) from d 85 to 91. Using a stair-step vs. constant supplementation amount (1.05 to 1.95% vs. 1.50% of BW) before the breeding season reduced intravaginal temperatures and increased overall ADG in Bos indicus-influenced beef heifers.

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PSIII-7 Determining the requirement of puberty induction to the reproductive performance of Bos indicus-influenced heifers submitted to AI

Journal of Animal Science ◽

10.1093/jas/skaa278.425 ◽

2020 ◽

Vol 98 (Supplement_4) ◽

pp. 231-232

Author(s):

Thiago Martins ◽

Felipe A C C da Silva ◽

Mariana Sponchiado ◽

Gabriela A Soriano ◽

Leonardo M F Pinto ◽

...

Keyword(s):

Reproductive Performance ◽

Reproductive Tract ◽

Bos Indicus ◽

Prostaglandin Analogue ◽

Estrus Synchronization ◽

Point Increase ◽

Estrus Response ◽

To Receive ◽

D 23 ◽

Synchronization Protocol

Abstract Induction of puberty by treating heifers with progesterone (P4) inserts may favor pregnancy/AI (P/AI) to a subsequent estrus synchronization program. However, it remains to be elucidated whether induction is required when the synchronization program contains P4 supplementation. To address this question, yearling, Brahman-influenced heifers (mostly 3/8 Brahman) classified as pubertal (PUB; n = 363) or prepubertal (PRE; n = 214) based on the presence of a CL, were assigned to receive no P4 supplementation (NoCIDR) or a CIDR for 10 days, starting on D-23. On D-13, all heifers received a dose of prostaglandin analogue and CIDRs were removed. On D-9, all heifers were enrolled in a 6-day CIDR & TAI protocol. Heifers were serviced based on heat between D-2 and D0 or were TAI on D0. Reproductive tract scores (RTS, 1 to 5 scale) were evaluated on D-23 and D-3. Induction increased the proportion of PRE heifers bearing a CL on D-3 (PRE|CIDR: 60.3% vs. PRE|NoCIDR: 42.7%). Among heifers with CL on D-3, P/AI of PRE heifers (42.5%) was similar to that PUB (47.7%). Conversely, for heifers without CL on D-3, P/AI of PRE (14.7%) was lower than PUB (37.3%). RTS increased between D-23 and D-3 from 2.3 to 4.0 (CIDR) and 2.3 to 3.6 (NoCIDR). For every 1-point increase in RTS, P/AI was 6–9% greater. Despite hastened puberty, P/AI of PRE heifers were less (PRE|NoCIDR: 29.2% and PRE|CIDR: 30.4%) than that of PUB (PUB|NoCIDR: 50.7% and PUB|CIDR: 42.2%). Less PRE (42.5%) than PUB animals (69.7%) were AI at estrus, and heifers showing estrus had a higher P/AI (52.8% vs. 18.7%). In conclusion, induction is not required when the subsequent synchronization protocol for AI contains progesterone. Induction hastened puberty attainment but failed to improve estrus response and fertility to the synchronization protocol.

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Preweaning injections of bovine ST enhanced reproductive performance of Bos indicus-influenced replacement beef heifers

Journal of Animal Science ◽

10.1093/jas/sky016 ◽

2018 ◽

Vol 96 (2) ◽

pp. 618-631 ◽

Cited By ~ 3

Author(s):

M B Piccolo ◽

J D Arthington ◽

G M Silva ◽

G C Lamb ◽

R F Cooke ◽

...

Keyword(s):

Reproductive Performance ◽

Bos Indicus ◽

Beef Heifers

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EFFECTS OF GROUP-FED DIHYDROXYPROGESTERONE ACETOPHENIDE IN COMBINATION WITH AN INJECTION OF ESTRADIOL VALERATE, AND MELENGESTROL ACETATE ON ESTRUS SYNCHRONIZATION AND CONCEPTION IN BEEF HEIFERS

Canadian Journal of Animal Science ◽

10.4141/cjas69-016 ◽

1969 ◽

Vol 49 (1) ◽

pp. 113-117 ◽

Cited By ~ 2

Author(s):

V. N. Tripathi ◽

W. E. Howell

Keyword(s):

Oral Administration ◽

Reproductive Performance ◽

Conception Rate ◽

Estradiol Valerate ◽

Estrus Synchronization ◽

Beef Heifers ◽

Experimental Conditions ◽

Melengestrol Acetate

Trials were conducted with 208 heifers to study the effect of oral administration of two progestagens on reproductive performance. Under the experimental conditions employed, the levels of dihydroxyprogesterone acetophenide proved inadequate to suppress estrus during treatment. In trials 1 and 2, estrus was synchronized in 71 and 63% of melengestrol acetate (MGA) treated heifers, respectively. For MGA-treated heifers in trial 1, conception rate at the first synchronized estrus was comparable with that in controls, but in trial 2 conception was significantly lower than in controls. Conception rate to first breeding at the estrus subsequent to the MGA-synchronized estrus was comparable with that of controls.

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Effects on Synchronization and Reproductive Efficiency of Delaying the Removal of the Intravaginal Progesterone Device by 24 h in the 5d Co-synch Protocol in Heifers

Animals ◽

10.3390/ani11030849 ◽

2021 ◽

Vol 11 (3) ◽

pp. 849

Author(s):

Aitor Fernandez-Novo ◽

Sergio Santos-Lopez ◽

Jose Luis Pesantez-Pacheco ◽

Natividad Pérez-Villalobos ◽

Ana Heras-Molina ◽

...

Keyword(s):

Animal Welfare ◽

Reproductive Performance ◽

Artificial Insemination ◽

Fixed Time ◽

Reproductive Efficiency ◽

Beef Heifers ◽

Animal Management ◽

Commercial Farms ◽

Beef Herds ◽

Farm Economics

In beef herds, increasing animal welfare, improving reproductive performance and easing animal management are key goals in farm economics. We explored whether delaying the removal of the intravaginal progesterone device by 24 h in heifers synchronized with a 5d Co-synch 72-h protocol could improve reproductive efficiency of fixed-time artificial insemination (FTAI). In experiment 1, we examined the total synchronization rate (TSR) in cycling Holstein heifers. Heifers (13.4 ± 0.69 mo.) were randomly assigned to the standard 5d Co-synch 56-h protocol (5dCo56; n = 10), 5d Co-synch 72-h (5dCo72; n = 17), or the modified 5d Co-synch 72-h protocol, in which removal of the progesterone device was delayed by 24 h (6dCo48; n = 19). In experiment 2, 309 cycling beef heifers on 18 commercial farms were subjected to the 5d Co-synch 72-h or 6-d Co-synch 48-h protocol and conception rate (CR) studied. In experiment 1, the three protocols led no differences on TSRs of 80.0% (5dCo56), 88.2% (5dCo72), and 89.5% (6dCo48). In experiment 2, the CR from the beef heifers, observed during two consecutive reproductive seasons did not differ: 59.7% for 5dCo72 and 62.0% for 6dCo48 (p = 0.907). Therefore, delaying removal by 24 h provides satisfactory results without reducing reproductive efficiency of heifers.

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Estrus synchronization in beef heifers with progestin-based protocols

Theriogenology ◽

10.1016/j.theriogenology.2004.02.017 ◽

2004 ◽

Vol 62 (8) ◽

pp. 1518-1528 ◽

Cited By ~ 23

Author(s):

S.L. Wood-Follis ◽

F.N. Kojima ◽

M.C. Lucy ◽

M.F. Smith ◽

D.J. Patterson

Keyword(s):

Estrus Synchronization ◽

Beef Heifers

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Effect of Diet on Replacement Beef Heifer Growth and Reproductive Performance

Journal of Agricultural Studies ◽

10.5296/jas.v5i3.11635 ◽

2017 ◽

Vol 5 (2) ◽

pp. 26

Author(s):

Janice G. P. Bowman ◽

Bok F. Sowell

Keyword(s):

Reproductive Performance ◽

Average Daily Gain ◽

Average Weight ◽

Beef Heifers ◽

Roller Mill ◽

Feed Cost ◽

Alfalfa Hay ◽

Grass Hay ◽

Beef Heifer ◽

Daily Gain

One hundred-one crossbred beef heifers (average weight 256.1 kg) were used to evaluate the effects of diet during an 84-day period, on growth and reproductive performance. The four treatments were: 1) grass hay; 2) grass hay + 0.9 kg/day barley; 3) grass hay + 1.8 kg/day barley; and 4) alfalfa hay. Heifers were assigned randomly to 12 pens by weight (three pens/treatment). Prior to feeding, barley was cracked through a roller-mill. Heifers consuming alfalfa hay or grass hay + 1.8 kg barley gained 39% faster (0.68 and 0.74 kg/day, respectively; P = 0.01) than heifers consuming grass hay alone (0.51 kg/day). Heifers consuming grass hay + 0.9 kg barley were intermediate in average daily gain (ADG; 0.63 kg/day). Hay intake was 16% greater (P < 0.10) by heifers consuming alfalfa hay, grass hay, and grass hay + 0.9 kg barley compared with those consuming grass hay + 1.8 kg barley (average 8.1 vs 7.0 kg/day). Using costs (USD) of $0.066/kg, $0.099/kg, and $0.0935/kg for grass hay, alfalfa hay, and barley, respectively, feed cost/day was greatest (P < 0.01) for alfalfa hay ($0.81/day), intermediate for the grass hay + barley diets (average $0.63/day), and lowest for grass hay ($0.53/day). Cost/kg gain was less (P < 0.10) for grass hay + 1.8 kg barley compared with alfalfa hay. No diet differences (P > 0.70) were found in reproductive performance of the heifers. Feeding replacement heifers alfalfa hay resulted in performance equivalent to feeding grass hay + 1.8 kg barley, but the alfalfa hay diet had a higher cost.

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