Reducing post-partum anoestrous interval in first-calf Bos indicus crossbred beef heifers. 2. Responses to weaning and supplementation

1993 ◽  
Vol 44 (5) ◽  
pp. 1079 ◽  
Author(s):  
CS McSweeney ◽  
PM Kennedy ◽  
MJ D'Occhio ◽  
LA Fitzpatrick ◽  
D Reid ◽  
...  

Supplementation designed to increase the supply of glucose and amino acids, was compared with early weaning as strategies for reducing post-partum anoestrous in Bos indicusx Bos taurus (518x318) first-lactation heifers. Twenty-three pregnant heifers were allocated to four treatment groups and fed long-chopped hay (15.8 g N/kg dry matter) ad libitum and a complete mineral mixture throughout the experiment as well as 450 g molasses and 50 g urea per day during the final month of pregnancy. After calving, three groups were supplemented daily for 120 days with either 2 kg cracked rice (E), 0.4 kg formaldehyde-treated casein (P), or cracked rice (2 kg)+formaldehyde-treated casein (0.4 kg) (E+P); the unsupplemented control group had their calves weaned at 60 days post-partum. Supplemented animals had significantly higher intakes of hay (7- 1-7.3 v. 5.9 kg OM/day), weight gain (0.4-0.5 v. 0.0 kg/day) and body condition score (4.6-4.7 v. 4.3) than the unsupplemented heifers, but there were no differences between the supplemented groups in these variables. Unsupplemented animals and heifers fed P partitioned similar amounts of lactose and fat into milk, whereas secretion of both lactose and protein was significantly higher in the E+P and E groups. All control heifers ovulated within 14 days of their calves being weaned, whereas only two of the lactating supplemented heifers (EfP) showed cyclic ovarian activity at that time and three other lactating heifers ovulated several weeks later. The response to weaning occurred in heifers that had a liveweight and condition score of 374 kg and 4.3 respectively, which was 30-50 kg and a half unit in condition below the suckling heifers. In unsupplemented heifers showing ovarian cyclicity, acetate entry rate was less than half that of the supplemented animals, whereas glucose entry rate, adjusted for loss to lactose, was similar for both groups. Supplementation did not affect either the basal concentration or frequency of pulsatile release of luteinizing hormone (LH) at 60 days post-partum, or the LH response to gonadotrophin releasing hormone (5 8g GnRH). It is concluded that under the conditions of the present study, weaning had a greater effect than post-partum nutritional supplements on the resumption of ovarian activity in first-lactation heifers with moderate nutrition.

2004 ◽  
Vol 52 (4) ◽  
pp. 501-508 ◽  
Author(s):  
C. Ahuja ◽  
F. Montiel

Induction of ovulation for timed artificial insemination (TAI) with the Ovsynch protocol was evaluated in 49 anoestrous and lactating Bos taurus × Bos indicus cows. Palpation per rectum and transrectal ultrasonography were used on Days -30, -20, -10 and 0 (start of treatment) to confirm anoestrus but with the presence of follicles = 10 mm, and every other day during treatment to determine ovarian activity. Cows were randomly assigned to: (1) Ovsynch (n = 24; Day 0, 200 µg GnRH; Day 7, 150 µg PGF2a; Day 9, 200 µg GnRH + TAI 16 to 20 h later) and (2) control (n = 25; no treatment). Rates of ovulation for the first GnRH injection, detection of a corpus luteum (CL) at PGF2a injection, pregnancy and induction of cyclicity were greater (P < 0.05) with Ovsynch. There was no effect of body condition score (P ? 0.05). In conclusion, the Ovsynch protocol was not effective in obtaining acceptable pregnancy rate for TAI, but it was effective for induction of cyclicity in anoestrous and lactating Bos taurus × Bos indicus cows under tropical conditions.


1996 ◽  
Vol 47 (6) ◽  
pp. 927 ◽  
Author(s):  
PD Jolly ◽  
CS McSweeney ◽  
AC Schlink ◽  
EM Houston ◽  
KW Entwistle

Interactions between effects of undernutrition and weaning on the duration of post-partum anoestrus and associated variation in milk yield, suckling behaviour, and metabolic hormone levels in Droughtmaster [Bos indicus x Bos taurus (518, 3/8)] first-calf cows were studied in 2 successive years. Low body condition score at calving (3.5f 0.1, scale 1-9) was associated with prolonged post-partum anoestrous intervals in suckled cows, but provided cows were maintaining liveweight, ovarian cyclicity resumed within 50 days if calves were weaned 70 days post-partum. This response to weaning was totally inhibited in cows that calved in low body condition that lost liveweight post-partum (Year 1). In contrast, marked levels of post-partum liveweight loss (23%) did not affect resumption of ovarian cyclicity in response to weaning (at 50 days post-parturn), or time to conception, among cows that calved with high body condition scores (5.8 � 0.2, Year 2). Reduced milk yields and calf weight gains among underfed cows were associated with higher suckling frequencies and durations ( P < 0.05). Acyclic interval after weaning was negatively related to body condition score at weaning (P < 0.01), and positively related to preweaning suckling intensity (P < 0.01). The time taken to resume ovarian cyclicity after weaning increased by a factor of 1.2 for every half unit decrease in body condition score at weaning, and by a factor of 1.3 for every 30-min increase in time suckled per day prior to weaning. Within level of nutrition, higher frequencies and durations of suckling were associated with higher plasma prolactin levels. Plasma IGF-1 levels were consistently depressed in underfed cows, whereas plasma insulin and GH levels were less affected by nutritional treatments. Effects of undernutrition in suckled cows appear to operate at least partly through interactions with milk yield and suckling intensity. Management of post-partum anoestrus in Bos indicus cows should focus on the conservation of cow body condition and on the strategic use of early weaning.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 236-237
Author(s):  
Thiago Martins ◽  
Cecilia Constantino Rocha ◽  
Joseph D Driver ◽  
Owen Rae ◽  
Mauricio A Elzo ◽  
...  

Abstract Bos taurus X Bos indicus crossbreeding is commonly used in tropical and subtropical regions to enhance beef production. The effect of Bos indicus genetics on pregnancy to AI (P/AI) and AI + natural service (P/AI+NS) is understudied. We measured the indicus effect from a 30-year dataset of the University of Florida multibreed herd (MBH; n= 7105 animals). The MBH is composed of six breed groups, according to the following proportion of Brahman: 0–19%, 20–34%, 37% (Brangus), 40–59%, 60%-78% and 79%-100%. Estrus of all animals was synchronized using mainly the SelectSynch+CIDR protocol, followed by three-day AI based on heat or timed-AI (TAI) for non-heat animals. After TAI, animals were bred by NS. Breeding seasons lasted 91±18d. Pregnancy was diagnosed by rectal palpation and/or ultrasonography 30d after AI and 30d after removal of bulls. P/AI was affected negatively (P &lt; 0.001) by the proportion of Brahman, regardless of parity, but P/AI+NS was similar across breeding groups (Table 1). By logistic regression, each 1/32nd increment of Brahman influence reduced odds of P/AI by 0.5% (0/32nd = 51.4% to 32/32nd = 35.3%). The variables of body condition score (BCS), days post-partum (DPP) and body weight at the beginning of synchronization protocol did not explain the negative effect of indicus genetics on P/AI. However, indicus genetics were associated negatively with the proportion of animals AIed in heat (P &lt; 0.001). AI in heat resulted in twice as great (P &lt; 0.001) P/AI (65.4%; n = 984) than no-heat TAI (30.9%; n = 829). In conclusion, indicus genetics did not influence overall pregnancy rates at the end of a 90d breeding season. Nevertheless, indicus influence dampened estrus responses to protocols based solely on GnRH-PGF and progestin/progesterone, resulting on suboptimal P/AI (&lt; 40%).


1994 ◽  
Vol 45 (4) ◽  
pp. 795 ◽  
Author(s):  
H Hearnshaw ◽  
PF Arthur ◽  
R Barlow ◽  
PJ Kohun ◽  
RE Darnell

Post-weaning growth and body condition, puberty and pelvic size of 197 heifers comprising straightbred Hereford (HxH) and Brahman (BxB), first-cross (BxH) and back-cross (HxBH and BxBH) heifers were evaluated. The heifers were born over a 3 year period, and grazed improved and semi-improved pastures following weaning at Grafton, New South Wales. Prior to weaning, heifers had been reared by dams on three pasture systems (high, medium and low quality pastures). Heifers from low quality pre-weaning pasture had higher (P < 0.05) post-weaning liveweight gain than those from high and medium quality pastures. BxH heifers gained 71 g/day more (P < 0.05) than the mean gain of their contemporaries of the other genotypes, whose gains were similar, from weaning to either 26 or to 30 months of age. Liveweight at all ages was influenced by genotype x pre-weaning pasture system interaction. At 30 months of age, BxH heifers from high and medium pre-weaning pastures were the heaviest. At the same age, but from low quality pre-weaning pasture, heifers with crossbred dams (HxBH and BxBH) were the heaviest. Wither height depended significantly (P < 0.05) on the proportion of Bos indicus genes, increasing from 113.8 cm in the HxH heifers to 124.4 cm in the BxB heifers at 30 months of age. BxH heifers had a higher (P < 0.05) body condition score than their contemporaries of the other genotypes, which were in similar condition, at 26 and 30 months of age. On average (across pre-weaning pasture system), 9% of BxB heifers had reached puberty by 22 months of age compared to 62, 95, 82 and 64% (s.e.= 9) for HxH, HxBH, BxH and BxBH heifers respectively. No significant genotype differences were obtained in the height, width and size of the pelvic opening of the heifers, measured just prior to the beginning of the mating season at 26 months of age.


2007 ◽  
Vol 19 (1) ◽  
pp. 220
Author(s):  
G. A. Bo ◽  
L. C. Peres ◽  
D. Pincinato ◽  
M. de la Rey ◽  
R. Tribulo

An experiment was designed to evaluate the effect of the interval between thawing to deposition of the embryo into the uterine horn on pregnancy rates of in vivo-produced frozen–thawed embryos in 1.5 M ethylene glycol (direct transfer). Data were collected from 1122 embryo transfers performed in the same farm (Estancia El Mangrullo, Lavalle, Santiago del Estero, Argentina) during the spring and summer of 2004/05 and 2005/06 (6 replicates, ambient temperature between 20 and 40�C). Recipients used in all replicates were non-lactating, cycling, multiparous Bos taurus � Bos indicus crossbred cows with body condition score between 3 and 4 (1 to 5 scale) that were synchronized using fixed-time embryo transfer protocols. Briefly, the synchronization treatments consisted of the insertion of a Crestar ear implant (Intervet, Sao Paulo, Brazil) or a progesterone-releasing device (DIB; Syntex SA, Buenos Aires, Argentina), plus 2 mg of estradiol benzoate (EB; Syntex) intramuscularly (IM) on Day 0, and 400 IU of eCG (Folligon 5000; Intervet, or Novormon 5000; Syntex) IM plus 150 �g d-cloprostenol IM (Preloban; Intervet, or Ciclase; Syntex) on Day 5. Progestin devices were removed on Day 8 and all cows received 1 mg of EB IM on Day 9. All cows were examined by ultrasonography on Day 16 and those with a luteal area &gt;76 mm2 (by calculating the area of the CL minus the area of the cavity) received, on Day 17, frozen–thawed embryos by nonsurgical transfer. All embryos were Grade 1, and all were frozen in 1.5 M ethylene glycol at the Embryo Plus Laboratory (Brits, South Africa). After being stored in liquid nitrogen, the embryos were plunged directly (no air thawing) in a 30�C water bath for 30 s, and then transferred to the recipient cows by either one of two technicians. Based on the interval between thawing and transfer, the transfers were classified as being in one of 3 groups: Group 1: &lt;3 min; Group 2: 3 to 6 min; and Group 3: 6 to 16 min. The main reason for delayed transfers beyond 6 min was the replacement of one recipient for another because of difficulty in threading the cervix (1% of the total transfers) or a recipient falling down into the chute or with very bad disposition and behavior. Pregnancy was determined by ultrasonography 28 to 35 days after fixed-time embryo transfer, and data were analyzed by logistic regression. There were no effects of replicate, technician, CL area, recipient body condition score, embryo stage, and time from thawing to transfer on pregnancy rates. Pregnancy rates in the 3 thawing to transfer intervals were: Group 1: 215/385, 55.8%; Group 2: 372/655, 56.8%; Group 3: 42/82, 51.2%; P &gt; 0.6. These results may be interpreted to suggest that there is no significant effect of time from thawing to transfer (up to 16 min) in direct transfer embryos using Bos taurus � Bos indicus recipients transferred at a fixed time.


2010 ◽  
Vol 22 (1) ◽  
pp. 177 ◽  
Author(s):  
M. Ramos ◽  
L. Cutaia ◽  
P. Chesta ◽  
G. A. Bó

Two experiments were designed to evaluate the effect of the timing of fixed-time AI (FTAI) in relation to the removal of an intravaginal progesterone-releasing device (1 g of progesterone, DIB, Syntex SA, Buenos Aires, Argentina) on pregnancy rates in Bos indicus × Bos taurus cross-bred heifers. In experiment 1, 285 Bonsmara × zebu cross-bred heifers, between 18 and 24 months of age and with a body condition score (BCS) between 3.0 and 3.5 (1-5 scale) were used. On the day of initiation of treatment (Day 0), the heifers’ ovaries were palpated (92% of them had a CL) and they received a new DIB plus 2 mg of estradiol benzoate (EB; Syntex SA) and 250 μg of cloprostenol (Ciclase DL, Syntex SA). On Day 8, DIB devices were removed and all heifers received 250 μg of Ciclase plus 0.5 mg of estradiol cypionate (ECP; Cipiosyn, Syntex SA). At that time the heifers were randomly divided to receive FTAI between 48 to 49 h, 53 to 54 h, or 58 to 59 h after DIB removal. The heifers underwent FTAI with semen from 4 bulls by 2 inseminators. In experiment 2, 260 heifers from the same group as those used in experiment 1 (87% with a CL) were treated exactly as those in experiment 1, except that previously used DIB was inserted on Day 0. Pregnancy diagnosis was performed 30 days post-fixed-time AI by ultrasonography. The data were analyzed by logistic regression, taking into account the effect of time of FTAI, semen, and inseminator on pregnancy rates. In experiment 1, pregnancy rates were lower (P = 0.04) in the heifers undergoing FTAI between 48 and 49 h after DIB removal (46/95, 48.4%) than those undergoing FTAI 53 to 54 h (61/99, 61.6%) or 58 to 60 h (57/91, 62.6%) after DIB removal. However, no differences in pregnancy rates were found (P = 0.72) in experiment 2 between the 3 treatment groups, with 39/91 (42.9%) for the 48 to 49 h group, 45/89 (50.6%) for the 53 to 54 h group, and 35/89 (43.8%) for the 58 to 59 h group. There was no effect of the semen or inseminator (P > 0.2) in either experiment. We conclude that when Bos indicus × Bos taurus beef heifers are synchronized with new DIB devices and ECP, higher pregnancy rates are obtained in heifers undergoing FTAI late (between 53 to 60 h after DIB removal) than in those undergoing FTAI early (48 to 49 h after DIB removal). However, time of insemination does not apparently affect pregnancy rates when Bos indicus × Bos taurus beef heifers are synchronized with previously used DIB devices and ECP.


2005 ◽  
Vol 17 (2) ◽  
pp. 234 ◽  
Author(s):  
R. Tribulo ◽  
E. Balla ◽  
L. Cutaia ◽  
G.A. Bo ◽  
P.S. Baruselli ◽  
...  

Although several studies have investigated the relationship between circulating progesterone and pregnancy rates in cattle, the beneficial effect of treatments that increase progesterone concentrations, by insertion of a progesterone (P4) releasing device or induction of an accessory CL with hCG, GnRH, or LH treatment, has resulted in inconsistent effects on pregnancy rates in embryo recipients. An experiment was designed to evaluate the effect of hCG or GnRH treatment, given at the time of embryo transfer without estrus detection, on pregnancy rates in recipients treated with intrauterine P4-releasing devices, estradiol benzoate (EB), and eCG. The experiment was performed in two replicates; non-lactating Bos taurus × Bos indicus crossbred beef cows with a body condition score between 2.5 to 3.5 (1-to-5 scale) were used (replicate 1, n = 180; replicate 2, n = 140). All cows received 1 g of P4 via a P4-releasing device (DIB, Syntex, Argentina) and 2 mg EB i.m. (Syntex) on Day 0, and 400 IU of eCG i.m. (Novormon 5000, Syntex) plus 150 μg d(+)cloprostenol i.m. (Ciclase, Syntex) on Day 5. DIBs were removed on Day 8 and all cows received 1 mg EB i.m. on Day 9. Recipients were not observed for signs of estrus, and those >1 CL, or a single CL with an area >256 mm2, received 195 Grade 1 and 46 Grade 2 frozen/thawed “direct transfer” embryos on Day 17. At the time of embryo transfer, recipients were randomly allocated to 1 of 3 treatment groups to receive 1500 IU hCG (Ovusyn, Syntex), 50 μg Lecirelina (GnRH, Gonasyn, Syntex), or no treatment (control) at that time. Ovarian ultrasonography was performed on Day 0 to determine ovarian status (only cows with a CL or a follicle >10 mm and uterine tone were used), on Day 17 to measure CL area, and 40 days after embryo transfer to determine pregnancy status. Data were analyzed by logistic regression and the effects of replication, technician, treatment, and embryo quality were considered in the model. From the 320 recipients treated with a DIB plus EB and eCG, 241 (75.3%) were selected to receive an embryo. Nine (3.7%) and 1 (0.4%) of the selected recipients had 2 and 3 CL, respectively. Pregnancy rates did not differ between replicates (replicate 1: 80/140, 57.1%; and replicate 2: 57/101, 56.4%; P = 0.84), technicians (technician 1: 65/118, 55.1%; and technician 2: 72/123, 58.5%; P = 0.64), or treatments (hCG: 43/80, 53.8%; GnRH: 45/83, 54.2%; and control: 49/78, 62.8% P = 0.99). However, pregnancy rates were higher (P = 0.001) in recipients receiving Grade 1 embryos (121/195, 62.1%) than in those receiving Grade 2 embryos (16/46, 34.8%). GnRH or hCG treatment at the time of embryo transfer did not increase pregnancy rates in recipients synchronized with P4 releasing devices, EB, and eCG. Research was supported by Syntex S.A., Estancia El Mangrullo S.A., and Agencia Cordoba Ciencia S.E.


2011 ◽  
Vol 78 (4) ◽  
pp. 464-470 ◽  
Author(s):  
Valérie Piccand ◽  
Susanne Meier ◽  
Erwan Cutullic ◽  
Sara Weilenmann ◽  
Peter Thomet ◽  
...  

The objectives of the study were to compare the ovarian activity of Holstein-Friesian (CH HF), Fleckvieh (CH FV) and Brown Swiss (CH BS) dairy cows of Swiss origin with that of Holstein-Friesian (NZ HF) dairy cows of New Zealand origin, the latter being used as a reference for reproductive performance in pasture-based seasonal calving systems. Fifty, second-lactation NZ HF cows were each paired with a second-lactation Swiss cow (17, 15 and 18 CH HF, CH FV and CH BS respectively) in 13 pasture-based, seasonal-calving commercial dairy farms in Switzerland. Ovarian activity was monitored by progesterone profiling from calving to first breeding service. CH BS cows produced less energy-corrected milk (mean 22·8 kg/d) than the other breeds (26·0–26·5 kg/d) during the first 100 d of lactation. CH HF cows had the lowest body condition score (BCS) at calving and the greatest BCS loss from calving to 30 d post partum. Commencement of luteal activity (CLA) was later for NZ HF than for CH FV (51·5 v. 29·2 d; P <0·01), with CH HF and CH BS intermediate (43 d). On average, NZ HF and CH HF cows had one oestrous cycle before the onset of the seasonal breeding period; this was less (P<0·01) than either CH FV (1·7) or CH BS (1·6). There was a low prevalence of luteal persistency (3%) among the studied cows. First and second oestrous cycle inter-ovulatory intervals did not differ between breeds (20·5–22·6 d). The luteal phase length of CH BS during the second cycle was shorter (10·6 d) than that of the other breeds (13·8–16·0 d), but the inter-luteal interval was longer (9·8 d v. 7·0–8·0 d). The results suggest that the Swiss breeds investigated have a shorter interval from calving to CLA than NZ HF cows.


2014 ◽  
Vol 83 (1) ◽  
pp. 27-32 ◽  
Author(s):  
Silviu Ionuţ Borş ◽  
Gheorghe Solcan ◽  
Alina Vlad-Sabie

The aim of the present study was to determine the effects of propylene glycol on metabolic variables of hepatic function, body condition score, milk fat-protein concentration and reproductive performance of dairy cows after ending administration. Postparturient dairy cows (n = 200) of Holstein Friesian breed were divided into two groups of 100 individuals. The experimental group received during days 0-7 post partum an oral daily dose of 600 ml of propylene glycol; the control group was without any supplement. The hepatic enzymes, glucose, cholesterol and serum albumin were measured on days 10-15, 45-50 and 70 post partum. Reproduction indicators of dairy cows were calculated from the farm recording data and the milk data record from a regular dairy control (days 10, 20, 30, and 50 post partum). Animals that received propylene glycol in the first 7 days post partum had reduced activities of aspartate transaminase and gamma-glutamyl transferase, elevated cholesterol concentration (P < 0.05) and low milk fat percentage (P < 0.05) compared to control animals. Direct influence of propylene glycol drenching on the calving to first oestrus interval was observed, the smallest values being detected for the cows in the experimental group compared to the control group (P < 0.05). Our results suggest that some blood indicators of hepatic function, milk fat concentration and calving to first oestrus interval can be improved for 70 days post partum by the use of propylene glycol drenching in the first 7 days post partum. The beneficial effect of this treatment could be evaluated by easily available data, which can be used by practitioners in the field to analyze fertility problems in dairy herds and more exactly to examine whether metabolic stress, among other factors, is involved in the fertility problem.


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