Preweaning injections of bovine ST enhanced reproductive performance of Bos indicus-influenced replacement 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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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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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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A preliminary study of growth, serum prolactin and reproductive performance of beef heifers grazing -infected tall fescue

Theriogenology ◽

10.1016/0093-691x(92)90058-y ◽

1992 ◽

Vol 38 (3) ◽

pp. 375-384 ◽

Cited By ~ 14

Author(s):

M.D. Fanning ◽

J.C. Spitzer ◽

D.L. Cross ◽

F.N. Thompson

Keyword(s):

Reproductive Performance ◽

Tall Fescue ◽

Serum Prolactin ◽

Beef Heifers ◽

Preliminary Study

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PSV-4 Peri-estrus ovarian, uterine, and hormonal variables influence the uterine luminal fluid metabolome in beef heifers

Journal of Animal Science ◽

10.1093/jas/skab235.568 ◽

2021 ◽

Vol 99 (Supplement_3) ◽

pp. 309-310

Author(s):

Felipe Alves Correa Carvalho da Silva ◽

Gabriela da Silva ◽

Bruna Vieira ◽

Adomar Neto ◽

Cecilia Constantino Rocha ◽

...

Keyword(s):

Color Doppler ◽

Univariate Analysis ◽

Bos Indicus ◽

Essential Amino Acids ◽

Beef Heifers ◽

Spatial Changes ◽

Temporal And Spatial ◽

Cytology Brush ◽

Implantation Period ◽

Uterine Body

Abstract In cattle, uterine luminal fluid (ULF) is the main source of molecules that support embryo development and survival during the peri-implantation period. Overarching hypothesis was that peri-estrus changes in ULF volume through accumulation and resorption mechanisms influence ULF composition during the estrous cycle and early pregnancy. Objectives were (1) to characterize individual temporal and spatial changes in ULF volume, endometrial and luteal vascularity, endometrial and luteal size, and progesterone (P4) concentrations during the peri-estrus period in beef heifers and, (2) associate such changes with the metabolite composition in the ULF, four days after estrus. Fourteen Bos indicus heifers that presented a PGF2α responsive CL received 500 µg PGF2α analog i.m. and were examined daily by rectal B-mode and pulse-wave color-Doppler ultrasonography until the fifth day after estrus (estrus = d 0). Plasma P4 was measured daily. On d 4, the uterine body was sampled using a cytology brush for targeted metabolomic analysis by mass spectrometry. Multivariate analyses clustered heifers according to ovarian, uterine, and hormonal variables in clusters A (n = 5) and B (n = 8 heifers). Individual metabolite concentrations were compared between clusters A and B by univariate analysis using t-test after FDR correction. Concentrations of Pro, Ala, Leu, Gly, Val, Lys, Ile, Phe, Asp, Orn, Tyr, Arg, Trp, Suc, Cit, ADMA, the sum of essential Amino Acids (AA), sum of non-essential AA, sum of aromatic AA, and total AA were greater in cluster A (FDR ≤ 0.05). ULF volume dynamics and associated uterine, ovarian, and hormonal variables during the peri-estrus period presented a concerted variation among heifers, which was associated with the ULF composition four days after estrus. Potential implications for embryo receptivity and reproductive outcomes are the focus of the current investigation.

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