bluuebunny/crossref_metadata_2025_split huggingface dataset:
PSXII-20 Ovarian dynamics and fertility in beef cows administered a 5-day or 6-day CO-Synch protocol for timed artificial insemination
Authors: Crist Alexandria E , Motta Jessica Cristina Lemos , Hayden Cameron , Duran Benjamin , Mussard Martin 
Published: October 2021

Abstract
The 5-day CO-Synch is an extensively used TAI protocol; however, it requires multiple administrations of prostaglandin F2α (PGF). The objective of the present study was to evaluate the effect of increasing progesterone (P4) device insertion from 5 to 6 days during a TAI protocol on ovarian dynamics and fertility in beef cows. Suckled beef cows (n = 867) at six locations were randomly assigned to either a 5-day or 6-day CO-Synch. Cows received an intravaginal P4 device (CIDR, Zoetis) and 100 µg of gonadorelin acetate (GnRH, Parnell) on d-9 (6-day) or d-8 (5-day). On d-3 CIDR’s were removed, an estrus detection patch applied (Estrotect, Rockway Inc.) and either one (6-day) or two (5-day) doses of PGF (500 µg of cloprostenol sodium, Estroplan, Parnell) was administered. On d0 (72 h after CIDR removal) all cows received 100 µg of GnRH, estrus expression was evaluated, and AI was performed. Pregnancy was determined by ultrasonography 34 days after TAI. Ovarian dynamics were evaluated in a subset of animals (n = 20) between d-3 and d7 to determine preovulatory follicle size, time of ovulation and corpus luteum (CL) size. Data were analyzed using generalized linear mixed models (SAS 9.4). Cows in the 6-day group tended (P = 0.09) to have a larger maximum follicle diameter (16.2±0.4mm) than cows in the 5-day group (15.0±0.6mm). In addition, CL volume on d7 was greater (P = 0.01) in the 6-day (4302±495mm3) than 5-day (2406±455mm3) group. There were, however, no differences (P = 0.15) in the interval between CIDR removal and ovulation. Cows assigned to the 6-day group had greater (P &lt; 0.05) estrus expression [56.1% (215/385) vs 41.5% (161/388)] and pregnancy rate [54.6% (236/438) vs 47.4% (207/435)] than cows in the 5-day group. In conclusion, extension of the period of P4 device insertion in a prolonged proestrus protocol increases preovulatory follicle size, estrous expression, and fertility to TAI.
PSXII-15 Evaluation of later timing of fixed-time artificial insemination for beef cows when using sex-sorted semen following the 7 & 7 Synch protocol
Authors: Andersen Carson M , Smith Emily G , VanWye Genna M , Thomas Jordan M 
Published: October 2021

Abstract
An experiment was designed to evaluate later timing of fixed-time artificial insemination (FTAI) with sex-sorted semen among postpartum beef cows following the 7 & 7 Synch protocol, with the hypothesis that later timing would result in increased pregnancy rates (P/AI) among cows that expressed estrus prior to FTAI. Beef cows (n = 414) were blocked based on age and days postpartum (DPP) and randomly assigned to receive FTAI at 66 or 72 h after administration of prostaglandin F2α (PG). Estrus was synchronized using the 7 & 7 Synch protocol, which consists of administration of PG (500 μg cloprostenol) and insertion of an intravaginal progesterone-releasing insert (CIDR; 1.38 g progesterone) on Day 0, gonadotropin-releasing hormone (GnRH; 100 μg gonadorelin) on Day 7, and PG coincident with CIDR removal on Day 14. Estrus detection aids (EstrotectTM) were applied to all cows on Day 14, and activation status was recorded at fixed-time artificial insemination (FTAI) on Day 17. All cows that expressed estrus prior to FTAI received sex-sorted semen (4 × 106 cells per unit; SexedULTRA 4MTM). The proportion of cows expressing estrus prior to FTAI did not differ between treatments at this power of test [66 h: 71% (146/205); 72 h: 76% (158/209)]. Additionally, P/AI of estrous cows inseminated with sex-sorted semen did not differ between treatments [66 h: 44% (90/205); 72 h: 39% (82/209)]. In conclusion, later timing of FTAI following the 7 & 7 Synch protocol failed to improve P/AI of estrous cows inseminated with sex-sorted semen.
PSXII-23 Sirtuins expression and activity in bovine granulosa cells are regulated by hormones that influence ovarian steroidogenesis
Authors: Archilia Evandro C , Bello Camilo Andres P , Batalha Isadora M , Schütz Luis F 
Published: October 2021

Abstract
Sirtuins (SIRTs) are a family of seven NAD+-dependent histone deacetylases that regulate several biological reactions. How SIRTs regulate ovarian steroidogenesis in cattle remains to be fully unveiled. We hypothesize that SIRTs expression and activity are regulated by hormones that influence steroidogenesis in bovine granulosa cells (GC). Bovine ovaries were collected at an USDA-inspected commercial slaughterhouse and GC were isolated from small antral follicles (1–5 mm on surface diameter). Cells were treated with hormones that regulate ovarian folliculogenesis: FSH, IGF1, fibroblast growth factor (FGF) 2, FGF9, and their combinations. Cells were cultured for 24h for total RNA isolation (n = 6 pools) with miRNeasy microkit (Qiagen) or for 48h for isolation of nuclear and cytoplasmic extracts (n = 3 pools) with EpiQuik Nuclear Extraction Kit (Epigentek) according to the manufacturers’ instructions. Relative mRNA abundance was quantified via qPCR and expressed as 2-ΔΔCt using the relative comparative threshold cycle (Ct) whereas SIRTs activity in nuclear (SIRTs 1, 6, and 7) and cytoplasmic (SIRTs 2, 4, and 5) extracts was analyzed with the Epigenase Universal SIRT Activity/Inhibition assay kit (Epigentek) following the manufacturer’s instructions. Data were analyzed via ANOVA with GLM procedures of SAS for Windows. In terms of mRNA relative abundance, FSH+IGF1+IGF9 increased mRNA relative expression of SIRTs 2 to 7 in comparison to negative control and of SIRTs 2, 3, 4, 6, and 7 in comparison to FSH+IGF1; FSH+IGF1+IGF2 increased mRNA relative abundance of SIRTs 2 and 6 in comparison to FSH+IGF1; FGF2 alone increased SIRT1 in comparison to negative control (P &lt; 0.05). In term of SIRTs activity, FGF2 alone increased nuclear SIRTs activity in comparison to FSH, IGF1, FSH+IGF1, and FGF9 alone; FSH+IGF1+IGF2 increased cytoplasmic SIRTs activity in comparison to all treatments (P &lt; 0.05). Taken together, our data demonstrate that SIRTs expression and activity in bovine GC are regulated by hormones that influence steroidogenesis.
PSVIII-13 Are the heat stress days increasing in central northern Mexico?
Authors: Rodriguez-Martinez Rafael , Rivas-Madero Jesús Salvador , Robles-Trillo Pedro Antonio , Meza-Herrera César A , Rodriguez-Venegas Rafael 
Published: October 2021

Abstract
The Lagunera region, located in north central Mexico (24° 01′-26° 48 ‘LN and 101° 52′-101° 52′ 104° 40′ LO), produce the 21% of the national Mexican cow’s milk despite its climatic conditions (temperatures that fluctuate between 12.7 °C in January and 28.5 °C in June, with extremes of -5 °C and 41.5 °C, in addition to high solar radiation). The Temperature Humidity Index (THI) is the most useful indicator to define if there are heat stress conditions. To identify whether the days in which THI ≥68 (considering the threshold for signs of heat stress to appear in high-producing lactating cows) are increasingly reached at least one hour a day, the information of this indicator was recorded every 10 min daily, from 5 cow farms for 6 years (2015–2020), using the DiGiTH™ application (DiGiTH Technologies, Mexico), and regressions were run to identify if there is a relationship between the years of study and the THI levels. At any level of THI (≥68), there is a tendency to increase the number of days (10.05 d per year; R2 0.37); Disaggregating the data by THI level, this trend is also observed for levels 68 to 71 and 72 to 76 THI, registering an increase of 11.33 d (R2 0.45) and 9.03 d per year (R2 0.45) respectively. At the 77 - 79 THI level there is no trend, while at the ≥80 THI level, a decrease of 5.66 d per year was registered (R2 0.79). The results suggest that in this region, the days of heat stress are increasing, except for the level ≥80 THI, which indicates that palliative measures for heat stress should be intensified, and it is necessary to identify the reason for the decrease in heat stress days at the most dangerous level for livestock.
PSVIII-21 Multi-strain probiotics improved carcass characteristics and meat quality in pigs
Authors: Lee Ting-Yu , Young San-Land , Lin Chin-Sheng 
Published: October 2021

Abstract
Probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Many studies have demonstrated that probiotics could enhance the growth performance of swine, but rare evidence on meat quality. Therefore, a combination of Lactobacillus and Bacillus strains, SYNLACTMLeanAd (SLA), on carcass characteristic, meat quality and cecal microbiota of pig was conducted. 60 LYD weaned pigs were randomly allotted to control (corn-SBM based diet, CT), antibiotic (basal diet with 200 ppm Amoxicillin, AB), and multi-strain probiotics (basal diet with SLA at 106 CFU/g feed, SLA). Pigs fed treatment diets from 7 to 130 Kg BW (24 wks) with 20 pigs/TRT, and individual pigs used as experimental unit for carcass evaluation. There were no differences on carcass weight and carcass yield. Lean percentage of CT, AB and SLA were 54.01, 51.54, and 54.75%, respectively (P &gt; 0.05) with subcutaneous fat 21.59, 21.21, 17.22%, and backfat 3.08, 3.21, 2.76 cm, individually (P &gt; 0.05). However, the longissimus muscles area was improved (62.77 vs. 68.42 vs. 91.59 cm2, P &lt; 0.05), loin weight increased (3.52 vs. 3.49 vs. 4.52 Kg, P &lt; 0.05) with greater marbling score (2.38 vs. 1.80 vs.2.78, P &lt; 0.05) in SLA. Sensory evaluation showed pigs fed SLA had higher juiciness score (3.55 vs. 3.18 vs. 3.91, P &lt; 0.05) with better overall acceptance. It is unclear pork quality was different between treatments; however, cecal microbiome gene sequencing suggested a potential linkage of gut microbiota modification and pork quality by AB or SLA feeding.
PSVIII-11 Agent-based simulation model to evaluate the economic performance of reproductive programs in beef cattle
Authors: Ojeda-Rojas Oscar A , Gonella-Diaza Angela Maria M , Sartorello Gustavo L , Hauber Gameiro Augusto H 
Published: October 2021

Abstract
The objective of this study was to create a stochastic, agent-based simulation model to compare the economic performance of reproductive strategies in beef cattle. The model was parameterized using data from a real herd and the scientific literature. The scenarios evaluated were: natural mating (NM) only (ONM); one timed artificial insemination (TAI) plus NM (1TAI+NM); two TAI plus NM, with 24, 32, and 40 days between TAI (2TAI/24+NM, 2TAI/32+NM, and 2TAI/40+NM, respectively); three TAI without NM, with 24, 32, and 40 days (3TAI/24, 3TAI/32, and 3TAI/40, respectively), and three TAI plus NM, with 24 and 32 days (3TAI/24+NM and 3TAI/32+NM, respectively). The initial female herd was 400 and remained constant. The bull population varies from 0 to 15, depending on the scenario. The outcomes for each scenario are assessed on 32 farms, using a 5000-day time horizon at one-day time intervals and an animal-by-animal basis. The 3TAI/24+NM scenario resulted in the highest incomes (US$ 96,479.2 ± 709.8), while ONM had the least value (US$ 79,753.4 ± 741.9). The total operating cost was highest for 3TAI/24+NM (US$ 101,720.6 ± 79.2) and lowest for ONM (US$ 90,898.6 ± 59.2). However, when the total operating cost was evaluated per kg of weaned calf, the highest and lowest costs were for ONM (US$ 2.8 ± 0.0/kg) and 2TAI/24+NM (US$ 2.17 ± 0.0/kg), respectively. The 2TAI/24+NM (US$ -4,651.3 ± 630.7) scenario presented the best net margin, while the lowest result was for 3TAI/40 (US$ -12,590.0 ± 746.3). Our model suggests that reproductive strategies that use TAI have better economic performance than those under ONM. However, when three TAI were performed with 40 days, the benefit was lower, and even for some analyzes, it was worse than the ONM. The 2TAI/24+NM scenario outperformed the others because of the contrast between its high income with moderate costs.
PSVIII-15 Effect of Endovac-Beef vaccination on performance, dietary energetics, and carcass characteristics of growing-finishing calf-fed Holstein steers
Authors: Latack Brooke C , Carvalho Pedro H , Zinn Richard A 
Published: October 2021

Abstract
Objectives were to evaluate the influence of ENDOVAC-Beef® (Endovac Animal Health, Columbia, MO) vaccination on calf-fed Holstein steer growth performance, dietary energetics, and carcass characteristics. Fifty Holstein steer calves were utilized in a 322 d trial. Calves were blocked by initial shrunk body weight (134 ±5 kg) and randomly assigned to treatments within weight groups to 10 pens (5 steers per pen, 5 pens per treatment). Five pen groups received the ENDOVAC-Beef vaccination on d 28 and d 56, and the remaining 5 pens did not receive the ENDOVAC-Beef vaccination. All steers were fed the same steam-flaked corn-based growing-finishing diet. Vaccination did not affect (P ≥ 0.10) live weight, average daily gain, and dry matter intake during the 322 d feeding period. However, vaccination increased (P ≤ 0.04) gain efficiency and estimated dietary net energy values (NE) during the first 112 d on feed. Vaccination did not affect (P ≥ 0.14) gain efficiency or estimated dietary NE during the final 112 to 322 d, or over the entire feeding period (1 to 322 d). Vaccination did not affect (P ≥ 0.31) hot carcass weight, dressing percentage, and marbling score. However, vaccinating calf-fed Holstein steers with ENDOVAC-Beef increased (P ≤ 0.01) longissimus muscle area (LMA; 86.5 vs 76.8 cm2) and retail yield (51.3 vs 50.4); but, tended to increase (P = 0.07) carcass fat thickness. Morbidity and pink eye infection were low and not affect by treatment (P ≥ 0.18). We conclude that while vaccinating calf-fed Holstein steers with ENDOVAC-Beef did not have an overall effect on growth-performance, it increased (13%) LMA and retail carcass yield (1.8%).
PSVIII-19 Greenhouse gas emissions from beef cattle production in Brazil: how we can mitigate from animal operations?
Authors: Aurea Andre Pastori D , da Silva Cardoso Abmael S , Fernandes Lauriston Bertelli , Reis Ricardo Andrade , Ferreira Luis Eduardo , Guimarães Yuri Santa Rosa 
Published: October 2021

Abstract
In Brazil beef cattle production is one of the most important activities in the agricultural sector and has an important impact on environmental and resources consumption. In this study assessed greenhouses gases (GHG) impacts from on farms representative productive system and the possible improvements of the production chain. Primary data from animal production index and feeding were collected from 17 farms, which covers 300.000 animals and 220.000 hectares. Emissions of methane, nitrous oxide and carbon dioxide were made using intergovernmental panel on climate change (IPCC) guidelines for national inventories. The GHG inventory included emissions from animals, feeds and operations for animal operation from “cradle to farm gate”. Emissions of each farm were converted to carbon dioxide equivalent (CO2eq) and divided by carcass production. Regression analysis between carbon dioxide equivalent and productive index was run to identify possible hotspot of GHG emissions. A large variation between farms were observed. The GHG yield ranged from 8.63 kg to 50.88 CO2eq kg carcass-1. The productive index age of slaughtering (P &lt; 0.0001), average daily gain (P &lt; 0.0001) and productivity (P = 0.058) per area were positive correlated to GHG yield. While no correlation was found with stocking rate (P = 0.21). Improvements of the production chain could be realized by accurate animal management strategies that reduce the age of slaughtering (feeding and genetic improvements) and gain individual or per area using strategic animal supplementation and pasture management, in order to obtains reduction of GHG emissions of beef cattle.
PSVIII-12 An economic and emergy approach to evaluate the level of sustainability of lamb production: A case study in Brazil
Authors: Moreno Danny Alexander Rojas , Bermudez Yuli Andrea Pena , Luiz Vitória Toffolo , De Almeida Taynara Freitas Avelar , de Freitas Rafaela Scalise Xavier , Gomes Lobo Annelise Aila G , Gameiro Augusto H Hauber , Da Silva Bueno Ives Claudio C 
Published: October 2021

Abstract
This study employed the Economic Theory (ET) to calculate the production costs and the Emergy Methodology (EM) to identify the contributions of nature and economy of lambs produced in an intensive system located in Cravinhos city, State of São Paulo. In addition, was employed Emergy Methodology (EM) to identify the contributions of nature and economy in the system. The adopted scheme of cost allocation followed the classification according to ET, under Variable Cost (VC), Operational Fixed Cost (FC), Opportunity Costs of land and capital (OC), and Total Cost (TC). The EM manages to quantify all the resources used in the system in Contributions from Nature (I) and Feedback from the economy (F). The I originate from the Sum of Renewable (R) and Non-renewable (N) local resources, while that F is composed of the Materials (M) and Services (S) from the economic system. We found that to produce 935 lambs per year the TC was US$ 96,021.08. VC represented 19.08% of TC, while 76.6% were represented by FC, and 4.3% by the IF. The cost produced per animal and kg of live weight was US$ 72.73 and US$ 1.82, respectively. On the other hand, the total energy flow (Y) required by the system was 3.05E+16 seJ/yr (Solar Joules per year) for produce (Ep) 1.68E+06J/yr (Joules per year). Y was represented in a 53.92% by I (7.98% for R, from the sun, rain, and wind; and 45.94% for N, from the soil loss and groundwater), and 46,08% by F (27.8% for M, from the feed, minerals, steel, fueled, etc. and 10.7% for S, from manpower, other services external, taxes, etc.). These results show that the studied system has a %Renewability (%R = R / Y) of 7.98%. Thus, we can conclude that the system depends on 92.02% of resources from non-renewable sources.
PSVIII-16 Effect of estrous synchronization with natural service or fixed-timed artificial insemination with conventional or gender-skewed semen in beef females
Authors: Walker Julie , Perry George A , Rich Jerica J 
Published: October 2021

Abstract
Reproductive efficiency is critical for profitability, and age at weaning critically impacts weaning weight. The objective was to evaluate estrous synchronization and/or AI with conventional (CON) or gender-skewed (SEXED) semen on calving distribution. Beef females (n=1,620) were either 1) synchronized (7-CIDR:Syn) or not synchronized (Nonsyn) and mated to bulls, 2) synchronized (7-d CIDR) and mated to bulls (SynNS) or artificially inseminated (SynAI), or 3) synchronized (7-d CO-Synch plus CIDR) and AIed with CON or SEXED semen. Calving distribution and gender were determined at birth and were analyzed using the GLIMMIX procedure in SAS. Synchronization resulted in more calves born from d1 to 14 (P &lt; 0.01; 62% vs 47%) of the calving season. There was no differences (P = 0.31) between Syn and Nonsyn in the percent of calves born after d21, but between d22 and 42, more (P = 0.04) calves were born in the Nonsyn group. A greater proportion (P &lt; 0.02; 46% vs 38%) of calves were born in SynNS between d1 and 14 compared to SynAI. There was no difference between treatments (P &gt; 0.12) from d1 to 42, but more calves were born for SynAI after d43. With SEXED semen, there were no differences (P &gt; 0.14) between CON and SEXED for the proportion of calves born from d1 to 14 or d1 to 21; however, more of the desired gender were born in the SEXED group during d1 to 14 of the calving season (P &lt; 0.01; 84% vs 68%). More total calves were born from d22 to 42 in the SEXED group compared to the CON group (P &lt; 0.05; 49% vs 33%). In summary, synchronization increased the proportion of females that calved early in the calving season, and SEXED semen increased the proportion of the desired gender born early in the calving season.
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
Authors: Harvey Kelsey , Cooke Reinaldo F , Colombo Eduardo , Rett Bruna , Sousa Osvaldo , Harvey Lorin , Russell Jason , Pohler Ky G , Brandão Alice 
Published: October 2021

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 &lt; 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.