PSXIII-17 Supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn to beef cows during gestation: post-weaning responses of offspring reared as replacement heifers or feeder cattle

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 432-432
Author(s):  
Kelsey Harvey ◽  
Reinaldo F Cooke ◽  
Eduardo Colombo ◽  
Bruna Rett ◽  
Osvaldo Sousa ◽  
...  

Abstract Beef cows and their progeny were used to evaluate the effects of supplementing organic-complexed or inorganic Co, Cu, Mn, and Zn during gestation: on offspring reared as replacement heifers or feeder cattle. Non-lactating, pregnant beef cows (n = 190) were ranked by parity, pregnancy type, body weight (BW) and body condition score (BCS), at 117 ± 2.2 d of gestation (d 0) and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). From d 0 to calving, cows were maintained in a single pasture and individually offered treatments three times a week. Calves were weaned at 6 mo of age (d 367) and preconditioned for 45-d. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P < 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Therefore, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance of steer progeny until slaughter, but hastened puberty attainment in female progeny reared as replacement heifers.

Author(s):  
Kelsey M Harvey ◽  
Reinaldo F Cooke ◽  
Eduardo A Colombo ◽  
Bruna Rett ◽  
Osvaldo A de Sousa ◽  
...  

Abstract One hundred and ninety non-lactating, pregnant beef cows (¾ Bos taurus and ¼ Bos indicus; 138 multiparous and 52 primiparous) were assigned to this experiment at 117 ± 2.2 d of gestation (d 0). Cows were ranked by parity, pregnancy type (artificial insemination = 102, natural service = 88), body weight (BW) and body condition score, and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). The INR and AAC provided the same daily amount of Cu, Co, Mn, and Zn, based on 7 g of the AAC source. From d 0 to calving, cows were maintained in a single pasture and segregated three times weekly into 1 of 24 individual feeding pens to receive treatments. Calves were weaned on d 367 (200 ± 2 d of age), managed as a single group for a 45-d preconditioning period (d 367 to 412), and transferred to a single oat (Avena sativa L.) pasture on d 412. Heifer calves were moved to an adjacent oat pasture on d 437, where they remained until d 620. Heifer puberty status was verified weekly (d 437 to d 619) based on plasma progesterone concentrations. Steer calves were shipped to a commercial feedlot on d 493, where they were managed as a single group until slaughter (d 724). Plasma cortisol concentration was greater (P = 0.05) in AAC calves at weaning but tended to be less (P = 0.10) on d 370 compared with INR calves. Mean plasma haptoglobin concentration was greater (P = 0.03) in INR vs. AAC calves during preconditioning, and no treatment effects were noted (P = 0.76) for preconditioning average daily gain (ADG). Puberty attainment was hastened in AAC heifers during the experiment (treatment × day; P < 0.01), despite similar (P = 0.39) ADG between treatments from d 412 to 620. Expression of myogenin mRNA in the longissimus muscle was greater (P = 0.05) in INR vs. AAC heifers on d 584. No treatment effects were detected (P ≥ 0.24) for steer ADG from d 412 until slaughter, nor for carcass quality traits. Hepatic mRNA expression of metallothionein 1A was greater (P = 0.02) in INR vs. AAC steers on d 586. In summary, supplementing Co, Cu, Zn, and Mn as organic complexed instead of sulfate sources to beef cows during the last 5 mo of gestation did not improve performance and physiological responses of the steer progeny until slaughter, but hastened puberty attainment in the female progeny reared as replacement heifers.


Author(s):  
Kelsey M Harvey ◽  
Reinaldo F Cooke ◽  
Eduardo A Colombo ◽  
Bruna Rett ◽  
Osvaldo A de Sousa ◽  
...  

Abstract One hundred and ninety non-lactating, pregnant beef cows (¾ Bos taurus and ¼ Bos indicus; 138 multiparous and 52 primiparous) were assigned to this experiment at 117 ± 2.2 d of gestation (d 0). Cows were ranked by parity, pregnancy type (artificial insemination = 102, natural service = 88), body weight (BW) and body condition score (BCS), and assigned to receive a supplement containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 95) or 2) an organic complexed source of Cu, Mn, Co, and Zn (AAC; Availa®4; Zinpro Corporation, Eden Prairie, MN; n = 95). The INR and AAC provided the same daily amount of Cu, Co, Mn, and Zn, based on 7 g of the AAC source. From d 0 to calving, cows were maintained in a single pasture and were segregated three times weekly into 1 of 24 individual feeding pens to receive treatments. Cow BW and BCS were recorded on d -30, d 97, upon calving, and at weaning (d 367). Milk production was estimated at 42 ± 0.5 d postpartum via weigh-suckle-weigh (WSW). Liver biopsies were performed in 30 cows/treatment on d -30, 97, upon calving, and the day after WSW. Calf BW was recorded at birth and weaning. Liver and longissimus muscle (LM) biopsies were performed in 30 calves/treatment upon calving and 24 h later, the day after WSW, and at weaning. No treatment effects were detected (P ≥ 0.49) for cow BCS during gestation, despite AAC cows having greater (P = 0.04) BW on d 97. Liver Co concentrations were greater (P < 0.01) for AAC compared to INR cows, and liver concentrations of Cu were greater (P = 0.02) for INR compared to AAC cows on d 97. Upon calving, INR cows had greater (P ≤ 0.01) liver Cu and Zn concentrations compared to AAC cows. No other treatment differences were noted (P ≥ 0.17) for cow and calf liver trace mineral concentrations. Cows receiving AAC had greater (P = 0.04) hepatic mRNA expression of metallothionein 1A at calving, and their calves had greater (P = 0.04) hepatic mRNA expression of superoxide dismutase at weaning. Milk production did not differ between AAC and INR cows (P = 0.70). No treatment effects were detected (P ≥ 0.29) for mRNA expression of LM genes associated with adipogenic or muscle development activities in calves at birth and weaning. Calf birth and weaning BW also did not differ (P ≥ 0.19) between treatments. In summary, supplementing Co, Cu, Zn, and Mn as organic complexed or sulfate sources to beef cows during the last 5 mo of gestation yielded similar cow-calf productive responses until weaning.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 129-130
Author(s):  
Gleise Medeiros da Silva ◽  
Tessa M Schulmeister ◽  
Federico Podversich ◽  
Federico Tarnonsky ◽  
Maria E Zamora ◽  
...  

Abstract A completely randomized design study with a 2 × 2 factorial arrangement of treatments evaluated the impact of artificial shade (SHADE or NO SHADE) and breed (ANGUS vs. BRANGUS) on performance of cows, nursing calves, and subsequent offspring. Twenty-four Angus and 24 Brangus black-hided pregnant cows (579 ± 8 kg BW; 6.5 yr; approximately 85 d of gestation) and their nursing calves were randomly allocated to 12 ‘Pensacola’ bahiagrass pastures (Paspalum notatum Flüggé; 1.3 ha; n = 4 pairs/pasture), with or without access to artificial shade (NO SHADE BRANGUS [NSB], NO SHADE ANGUS [NSA], SHADE BRANGUS [SB], and SHADE ANGUS [SA]) for 56 d during summer. Body condition score (BCS) of cows and BW of pairs were obtained on d -1, 0, 55, and 56 (weaning weight). Following weaning, calves were randomly allocated to 4 pens (n = 12/pen) equipped with GrowSafe feed bunks for 14 d to measure feed intake (DMI) and efficiency (G:F). A shade × breed interaction (P < 0.05) was observed for average daily gain (ADG) and BCS of cows, with SB being greatest (P ≤ 0.05). Pre-weaning calf ADG tended to be greater (P = 0.10) for SHADE vs. NO SHADE. Weaning weight and BW 14-d post-weaning were lesser for NSB vs. NSA, SA, and SB, whereas no differences in DMI, ADG, or G:F were observed (P > 0.11). Gestation length was greater for SHADE vs. NO SHADE cows (292 vs. 274; P = 0.02), but calf birth weight was not different. Providing artificial shade to pregnant-lactating beef cows positively impacted the growth of Brangus but not Angus cows. However, weaning BW of calves from Angus cows regardless of shade access did not differ from that of Brangus calves with shade. Further research should investigate the potential long-term effects of shade on the subsequent offspring.


2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 51-52
Author(s):  
Alice Brandão

Abstract Option 1, Fetal Programming Only: Non-lactating, pregnant, multiparous Angus × Hereford cows (n = 104) were ranked by pregnancy sire (1 of 2 sires), body weight (BW), and body condition score (BCS) on d -15 of the experiment (d 180 of gestation). Cows were then assigned to receive: (1) 195 g/cow daily of CSSO (n = 52) or 2) 170 g/cow daily of CON (n = 52). Cows received treatments individually from d 0 to calving. Calves were weaned on d 290 of the experiment, preconditioned for 35 d, and placed in a feedyard until slaughter (d 514). Cows receiving CSSO and their calves had greater (P < 0.01) plasma concentrations ω-6 PUFA compared with CON after calving. Colostrum IgG and calf plasma IgG concentrations 24 h after birth were greater (P ≤ 0.02) in CSSO vs. CON cattle. Calves from CSSO cows had greater (P ≤ 0.05) expression of adipogenic and myogenic genes in the longissimus muscle compared with CON. No treatments differences in birth BW, weaning BW, and final preconditioning BW were noted (P ≥ 0.36). Average daily gain and final BW in the feedyard were greater (P ≤ 0.05) in steers from CSSO cows compared with CON. The incidence of calves diagnosed with BRD that required a second antimicrobial treatment was less (P = 0.03) in calves from CSSO cows, resulting in reduced (P = 0.05) need of treatments to regain health compared with CON. Upon slaughter, LM area was greater (P = 0.03) in calves from CSSO cows compared with CON. Collectively, these results are indicative of programming effects on postnatal offspring growth and health resultant from CSSO supplementation to late-gestating cows. Hence, supplementing CSSO to beef cows during pregnancy might be a feasible alternative to optimize offspring productivity and welfare. Option 2, Fetal Programming and Fat Tubs: Two experiments were conducted to evaluate: (1) effects of calcium salts of soybean oil (CSSO) supplementation to late gestating beef cows on the performance of the offspring; (2) the viability of utilizing low-moisture molasses-based blocks (LMB) as a delivery method for CSSO supplementation. In experiment 1, non-lactating, pregnant, multiparous Angus × Hereford cows were assigned to receive: (1) 195 g/cow daily of CSSO (n = 52) or (2) 170 g/cow daily of CON (n = 52) from d 195 of gestation until calving. CSSO cattle had greater (P < 0.01) plasma concentrations ω-6 PUFA; greater (P ≤ 0.02) colostrum and calf plasma IgG concentrations; greater (P ≤ 0.05) expression of adipogenic and myogenic genes in the longissimus muscle (LM); required fewer microbial treatments for BRD (P = 0.05) and had greater LM area compared to CON cohorts. In experiment 2, non-lactating, non-pregnant, multiparous beef cows were allocated to 1 of 9 pens (n = 9 pens; 4 cows/pen) and each pen was assigned to receive: 1) NOSUPP, hay only diet; 2) LMB, self-fed LMB supplement containing 24.7% DM CSSO; 3) CONC, hand-fed supplement identical to LMB. The design was a replicated 3 x 2 Latin square with 2 periods of 42 d, and a 21-d washout interval. Supplement DM intake did not differ (P = 0.39) between LMB and CONC cows from d 14 to 42 as designed, despite a greater variation in daily intake of LMB vs. CONC (treatment × day interaction; P < 0.01). No treatments effects were noted (P ≥ 0.40) for hay intake, BCS, and BW. From d 14 to 42, plasma concentrations of, ω-6 PUFA (P < 0.01) in CONC and LMB vs. NOSUPP cows. Hence, the use of self-fed LMB appears to be a valid strategy to provide CSSO to forage-fed beef cattle.


2017 ◽  
Vol 29 (1) ◽  
pp. 111 ◽  
Author(s):  
G. A. Bó ◽  
A. Cedeño ◽  
A. Tribulo ◽  
S. Andrada ◽  
R. Tribulo ◽  
...  

We have previously shown that expression of oestrus significantly influences the time of ovulation and pregnancy rates to timed-AI (P/TAI) in beef cattle synchronized with progesterone devices and oestradiol (Bó et al. 2016 Theriogenology 86, 388–396). Furthermore, delaying TAI from 48 h to 54–58 h after device removal improved P/TAI of those animals not showing oestrus by 48 h. The objective of the present study was to determine whether the administration of GnRH to those animals not showing oestrus by 48 h after device removal had an impact on P/TAI. Non-lactating and suckled beef cows and heifers (Bonsmara, Brangus, and Braford; n = 868), with a corpus luteum (CL) or a follicle ≥8 mm in diameter detected by ultrasonography (Mindray DP 30 Vet, 7.5 MHz, China) and body condition score 2 to 4 (1 to 5 scale) were synchronized in 3 replicates. On Day 0, animals received a progesterone device (DIB 0.5 g, Zoetis, Argentina) and 2 mg of oestradiol benzoate (Von Franken, Argentina). On Day 8, DIB were removed and cows received 0.150 mg of D+cloprostenol (Río de Janeiro, Argentina) plus 0.5 mg oestradiol cypionate (Cipiosyn, Zoetis). In addition, all cows were tail-painted on the sacrococcygeal area (CeloTest, Biotay, Argentina) at DIB removal and were observed to determine the expression of oestrus, according to the percentage of paint loss (PL) 48 h later. The animals that showed oestrus (PL > 30%) were recorded and TAI at that time while those with PL ≤ 30% (not in oestrus) were randomly allocated to receive 100 μg of gonadorelin (GnRH; Gonasyn, Zoetis) or no treatment and TAI between 54 to 58 h after DIB removal. Pregnancy was diagnosed by ultrasonography at 45 days after TAI, and data were analysed by logistic regression. There were no significant differences among replicates, inseminators, semen source or animal class (dry cows, suckled cows or heifers; P > 0.11). However, animals showing oestrus by 48 h after DIB removal had higher P/TAI (371/666; 55.7; P < 0.04) than those that did not show oestrus (96/202; 47.5%). Within animals not showing oestrus at 48 h, those that were in oestrus by the TAI at 54 to 58 h had higher P/TAI (71/124, 57.3%; P < 0.01) than those that did not show oestrus within that period (27/78; 34.6%). In addition, P/TAI was higher (P < 0.01) in animals that received GnRH (66/113; 58.4%) than in those that did not receive GnRH (30/89; 33.7%). In conclusion, the expression of oestrus significantly affected P/TAI in beef cattle synchronized with progesterone devices and oestradiol. Furthermore, treatment of animals not showing oestrus by 48 h after DIB removal with GnRH resulted in improved P/TAI performed 6 to 10 h later.


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.


2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Matheus Fellipe de Lana Ferreira ◽  
Luciana Navajas Rennó ◽  
Isabela Iria Rodrigues ◽  
Edenio Detmann ◽  
Mário Fonseca Paulino ◽  
...  

Abstract Background Metabolic profile evaluation is a tool widely used in ruminant nutrition as metabolic cues that relate nutrition to physiology. Metabolic and hormonal traits change during pre-partum and lactation according to parity in dairy cows, but studies of beef cows under grazing are scarce. The present study aimed to evaluate how metabolic and hormonal traits change over time, their relationship to performance, and determine if these factors differ according to the parity order of grazing beef cows. Thirty-six pregnant Nellore cows (12 nulliparous, 12 primiparous, and 12 multiparous) were used. The study started at 60 d prepartum until 203 d of lactation. Results The initial body weight (BW) and final BW were higher for multiparous cows (P > 0.05). An interaction occurred between parity and day (P < .0001) for body condition score. Nulliparous and primiparous body condition score were reduced from − 60 prepartum to 30 postpartum, then stabilized 60 postpartum (P < 0.05), while multiparous maintained body condition score from − 60 days until 60 days postpartum (P > 0.05). Calf BW, final BW, and average daily gain did not differ between parities (P > 0.05). Effect of day (P < 0.05) was detected for non-esterified fatty acids, triglycerides, total cholesterol, LDL, VLDL, progesterone, and insulin. An interaction was observed between parity and days for glucose, HDL, β-hydroxybutyrate, creatinine and IGF-1 (P < 0.05). Parity affected serum urea nitrogen, total proteins, albumin, and globulins (P < 0.05). Parity and day relative to calving did not impact total T3 and T4 (P > 0.05). Conclusions Hormonal and metabolic profile is strongly influenced by the stage of lactation. Time effects (pre-partum and lactation period) were more pronounced in nulliparous since they displayed more unbalanced metabolic and hormonal traits and lowered BCS pre- and postpartum.


2006 ◽  
Vol 18 (2) ◽  
pp. 288 ◽  
Author(s):  
P. Chesta ◽  
D. Maraña ◽  
L. Peres ◽  
G. A. Bo

An experiment was designed to evaluate the effect of the time of removal of an intravaginal progesterone (P4) releasing device and GnRH treatment on the interval to and the distribution of ovulations in beef cows superstimulated with Folltropin-V (Bioniche Animal Health, Belleville, Ontario, Canada). Red Angus donors (22 cows and 12 heifers) with a body condition score between 2.5 to 3.5 out of 5 were blocked by parity and randomly assigned to one of four treatment groups in a 2 × 2 factorial design. On Day 0, all donors received an i.m. DIB vaginal device (Syntex, Argentina) plus 2.5 mg estradiol-17β and 50 mg P4 (Laboritorio Rio de Janeiro, Argentina). Superstimulatory treatments were initiated on Day 4, with a total dose of 320 mg (cows) or 200 mg (heifers) NIH-FSH-P1 (Folltropin-V; Bioniche Animal Health, Inc., Belleville, Ontario, Canada) in twice daily i.m. injections over 4 days. All cows received PGF treatment (150 μD(+)cloprostenol: Ciclase; Syntex) in the morning and afternoon of Day 6 and were randomly divided to have DIB devices removed at the time of the second PGF treatment (Day 6.5) or 12 h later (Day 7). On Day 8, donors were further subdivided to receive GnRH (0.050 mg Lecirelina, Gonasyn; Syntex) or no further treatment, and all cows were fixed-time AI either 60 and 72 h after the first PGF injection (0 h). All cows and heifers were examined by ultrasonography every 8 h for a period of 120 h commencing at the time of DIB removal, to determine the time and distribution of ovulations. For each cow, mean time of ovulation was used for the statistical analysis. The distributions of ovulations were compared among groups by Levene's test, and then by ANOVA (equal variances) or Friedman two-way non-parametric ANOVA (unequal variances). No significant differences were detected between cows and heifers (P > 0.13) for the parameters evaluated, and data were combined. There was no effect (P > 0.22) of treatment on the number of ovulations (GnRH: 12.6 ± 1.6 vs. no GnRH: 15.1 ± 1.1 and Day 6.5: 13.7 ± 1.3 vs. Day 7: 14.3 ± 1.5), or numbers of transferable embryos (GnRH: 5.1 ± 1.1 vs. no GnRH: 3.1 ± 0.8 and Day 6.5: 3.5 ± 0.8 vs. Day 7: 4.81 ± 0.1). However, there was a significant effect of GnRH treatment and a GnRH-by-time-of-DIB-removal interaction on the distribution of ovulations (P < 0.05; Table 1). The administration of GnRH in a superstimulatory protocol using P4 releasing devices results in earlier and more synchronous ovulations than when GnRH is not used. Table 1. Distribution of ovulations (hours after the first PGF) in superstimulated Red Angus donors treated with progesterone-releasing devices (DIB) for 6.5 or 7 days with and without GnRH treatment on Day 8


Author(s):  
Carole Lafreniere ◽  
Robert Berthiaume ◽  
Leo Giesen ◽  
Cheryl Campbell ◽  
Dale Gardner ◽  
...  

Pregnant beef cows (56; 727 ± 102 kg BW) in second trimester were used to examine black spruce (BSP) needles and branches for replacing alfalfa silage in wintering cow diets. Five dietary treatments assessed BSP inclusion rates (0, 15, 22.5, 30, 37.5% in the diet) for 92 days up until 2 weeks before start of calving using a randomized complete block design (10-12 cows/treatment). There were linear decreases (P < 0.001) in total weight gain, average daily gain (ADG) and dry matter intakes (DMI) as amounts of dietary BSP increased. Low DMI feeding BSP may be attributed to palatability issues and lower rates of digestion. Changes in body condition score (BCS) increased(P < 0.003) as dietary BSP increased. These effects are supported by corresponding linear decreases (P < 0.001) for changes in rump fat cover and increases (P < 0.001) in serum non-esterified fatty acids as dietary BSP increased. Post-feeding of test diets, there were no dietary treatment differences (P > 0.42) for calf birth and weaning weights and cow pregnancy and culling rates. Based on this study, incorporation of BSP into gestating cow diets cannot be recommended.


2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 23-23
Author(s):  
Macy M Massengill ◽  
Thiago V Silva ◽  
Daniel H Poole

Abstract Previous experiments from our laboratory determined that postpartum beef cows with a functional corpus luteum (CL) at the start of an estrous synchronization protocol have greater pregnancy success to FTAI than those that did not have a CL. Therefore, it was hypothesized that incorporation a presynchronization program prior to FTAI in postpartum cows will improve pregnancy rates. The goal of this project was to compare the effectiveness of a presynchronization program prior to the 7-d CO-Synch+CIDR fixed timed artificial insemination (FTAI) protocol in postpartum cows. Postpartum cows (n = 310) at two locations were randomly assigned to receive either the presynchronization program, consisting of 2 PGF2α injections 14 d apart and 11 d prior to the start of the 7-d CO-Synch+CIDR protocol, or the 7-d CO-Synch + CIDR protocol. Following estrus synchronization, all cows were inseminated by trained technicians using semen from bulls of known fertility. Pregnancy status to FTAI was assessed using ultrasonographic diagnosis at 30 d post insemination. Data were analyzed using a MIXED procedure of SAS and examined for effects of inseminator, body condition score (BCS), and location and age. Statistical significance was determined at P &lt; 0.05 and a tendency at 0.05&lt; P &lt; 0.10. Age, BCS, and location did not affect (P &gt; 0.05) pregnancy rates. Cows exposed to the pre-synchronization program tended to have greater AI pregnancy rates compared to cows that did not receive the pre-synchronization program (57.7±5.3 vs. 46.9±5.3%, respectively; P = 0.0687). AI pregnancy rates were greater in cows with &gt;1 ng/mL P4 compared to cows with &lt; 1 ng/mL P4 at the start of FTAI (77.7±7 vs. 55.7±6.2%, respectively; P = 0.0204). Furthermore, AI pregnancy rates were decreased by inseminator C (26.1±7.4) compared to the other inseminators this breeding season (A-54.4±7.9; B- 62.3±5.3; D-57.8±7.2; and E -51.1±5.2; P = 0.0026). Based on these data, incorporating a pre-synchronization program to ensure the presence of a CL at the start of a FTAI protocol may improve pregnancy success in postpartum beef cows.


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