Department of Animal Sciences

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https://hdl.handle.net/10217/100318

These digital collections include faculty publications and theses and dissertations from the Department of Animal Sciences, and proceedings of the "Beef Cow Efficiency Forum" (1984). Due to departmental name changes, materials from the following historical departments are also included here: Animal Husbandry; Animal Nutrition.

See also the archival collection of Dr. Temple Grandin, a Colorado State University professor of animal sciences and world-renowned autism spokesperson.

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Now showing 1 - 6 of 6

Open Access
Association between patterns of body condition score during early lactation and conception rate in dairy cows
(Colorado State University. Libraries, 2021) Klug, Bailey, author; Pinedo, Pablo, advisor; Salman, Mo, committee member; Ahola, Jason, committee member
The installation of precision farming technology includes the utilization of image biometrics to calculate body condition scores (BCS) in Holstein cattle. Body condition scores help dairy operations to individually estimate energy reserves for each animal, based on subcutaneous fat found throughout the body but more specifically along the spine and the pelvis. Body condition scoring was originally a visual task performed by trained personnel that required specialized training and was often subjective. With the installation of a new automated system that has been validated (DeLaval Body Condition Scoring BCS™), BCS has become more accessible and flexible as a herd management tool. The hypothesis of this study was that low BCS, or a loss in BCS, during early lactation would reduce the rate of conception at multiple artificial inseminations (AI) increasing the number of days to pregnancy. Therefore, the overall objective of this research was to evaluate the association between BCS dynamics and the probability of conception at multiple AI. In chapter 1, a brief literature review about the challenges during the transition period, fertility, and BCS is presented. Chapter 2 is focused on the association between BCS and BCS changes (∆BCS) at multiple time points post-parturition and conception at first AI, while chapter 3 analyzed subsequent breedings up to fourth AI. This prospective observational study was performed on a single dairy operation in Windsor, Colorado, USA with a population of 2,885 Holstein cows including 1,460 primiparous and 1,425 multiparous cows. Study cows were housed in a free stall, cross-ventilated barn and milked three times per day. For study 1, automatic BCS was recorded using the DeLaval Body Condition Scoring BCS™. The records of BCS were gathered at 7, 21, 35, 49, and 60 d in milk (DIM) and on the d of first AI (dAI1). A 5-point scale was used to record BCS with 0.1 intervals. The categorization of BCS was defined as low (L; < mean - 1 SD), intermediate (M; mean ± 1 SD) and high (H; > mean + 1 SD). Changes in BCS were also categorized as no loss (NL; ΔBCS ≥ 0 points) and loss (Los; ΔBCS < 0 points). Multivariate logistic regression models were used to estimate the effect of explanatory variables on conception as a binary outcome. Additionally, a cox regression analysis with hazard ratios were used along with frequency analysis to further visualize the data. The overall conception rate at first AI was 30.1% (34.6 and 25.5% in primiparous and multiparous cows, respectively). Low BCS was associated with lower conception rate to first AI, while loss of BCS resulted in greater days to conception. The same study design was applied in chapter three; however, BCS records were gathered at 7, 30, and 60 DIM, and at dAI1, on the day of second AI (dAI2), third AI (dAI3), and fourth AI (dAI4). Low BCS during early lactation resulted in lower odds of pregnancy at multiple AI. Logistic regression analyses of ∆BCS also showed cows that lost BCS had greater odds of pregnancy at different inseminations. The likelihood that cows will conceive concurrent with a loss in BCS was greater across multiple AI compared to cows that did not lose BCS. The overall success of pregnancy was 27.8% at second AI (pAI2), 21.4% at third AI (pAI3), and 16.0% at fourth AI (pAI4). In conclusion, low BCS were associated with lower conception rates at AI. Furthermore, a loss in BCS were associated with greater number of days from parturition to conception to first AI However, a loss in BCS was associated with greater conception at second, third, or fourth AI. Monitoring daily automatic BCS provides potential for assessing future fertility of dairy cows.
Open Access
Attitudes and competencies of third year veterinary students towards their role as an animal welfare advocate and attitudes towards pain and pain mitigation practices in beef and dairy cattle in the United States by veterinarians and producers
(Colorado State University. Libraries, 2019) Johnstone, Ellizabeth Charlotte Spencer, author; Edwards-Callaway, Lily, advisor; Pinedo, Pablo, committee member; Ahola, Jason, committee member; Stuart, Amy K., committee member
Although leading veterinary organizations emphasize the importance of animal welfare knowledge, there exists a gap in current veterinary student animal welfare education and training. A survey instrument was created to assess third-year Doctor of Veterinary Medicine (DVM) student knowledge of key animal welfare topics, opinions regarding the inclusion of welfare education in the veterinary curriculum, and views on veterinarian responsibilities as advocates. In Spring 2018, Colorado State University added a required animal welfare course to the DVM curriculum. Pre- and post-course paper surveys were distributed to the third-year students enrolled in the animal welfare. One hundred thirty one completed pre-course surveys were collected and 125 completed post-course surveys were collected. Of the pre and post-course surveys collected, 61 were paired with identification codes and utilized for statistical comparison. Results indicated that the course led students to view the inclusion of an animal welfare course in the veterinary curriculum more favorably (p=0.009) and improved their confidence in conducting research on animal welfare topics (p<0.001). The course did not change students' sense of responsibility towards welfare advocacy. Associations were not found between attitudes towards these issues and demographic variables of home community, respondent gender, and track selection (p>0.06). Veterinarians were consistently ranked by students as the most influential member of a community in matters of animal welfare. Future research on the lack of veterinary student knowledge of animal welfare should be done on a national scale to facilitate strategic development of mandatory animal welfare courses in veterinary curricula. Future research should be designed to gain knowledge regarding DVM students' opinions and attitudes regarding effective methods of incorporating animal welfare education into their professional training. The objective of the second survey project was to evaluate the current pain management practices and opinions towards pain management in cattle of beef and dairy veterinarians and producers in the United States. Pain management strategies in livestock have evolved in the last few decades but a variety of obstacles continue to limit improvements in the use of pain mitigation by members of the cattle industries. One such obstacle is the lack of FDA-approved analgesic drugs for use in cattle in the United States which offers limited pain management options to cattle veterinarians and producers. An on-line survey was developed to investigate current use of pain mitigation by cattle veterinarians and producers. The survey was distributed electronically to multiple listservs in Summer 2018 (BEEF Magazine, American Association of Bovine Practitioners, National Milk Producers Federation Farmers Assuring Responsible Management evaluators, Dairy Moms and Dairy Girls Facebook groups; N=46,577). A total of 1,187 (2.5%) surveys were received; 41.9% of respondents identified as producers, 47.9% as veterinarians, and 10.2% as both. Multivariate logistic regression was used for analysis. Veterinarians (OR [95% CI] = 10.2 [7.21-14.4]) and producer-veterinarians (OR [95% CI] = 3.30 [2.02-5.39]) had significantly greater odds of using analgesia than producers in all cattle ages. Summary data suggest that analgesic use changed with cattle age; 57.6% of respondents used pain management in calves <2 months of age, while 71.6% of respondents used pain management in cattle more than 12 months of age. Respondents agreed that "cattle benefit from receiving analgesic drugs" (76.6%) and that "US/USDA/FDA regulations limit my ability to use analgesic drugs in cattle" (64.01%). Fifty-eight percent of respondents indicated their use of pain management had increased in the last 10 years. Data identify impediments to improving pain management practices in cattle. Results indicate the need for education and communication between veterinarians and producers on the necessity of pain management.
Open Access
Benchmarking animal handling outcomes and analyzing impacting factors on cow-calf operations
(Colorado State University. Libraries, 2022) Calaba, Elaine, author; Edwards-Callaway, Lily, advisor; Hess, Ann, committee member; Engle, Terry, committee member; Ahola, Jason, committee member
Animal handling is an important part of the cattle industry; proper handling of animals can improve animal welfare and increase consumer confidence. One way handling is assessed on cow-calf operations is through producer education programs, such as the Beef Quality Assurance (BQA) program. A part of these producer education programs is assessing animal handling outcomes. However, there has not been much research into the occurrence and implication of cow handling outcomes. The objectives of this study were to: 1) quantify handling outcomes on cow-calf operations in the United States and 2) investigate potential factors that may influence these outcomes. An assessment was developed by refining existing BQA Cow-Calf program outcome definitions in addition to questions about animal factors, facilities, and management factors. Handling outcomes observed included: Prod Use, Miscatch, Vocalization, Jump, Slip/Stumble, Fall and Run. A total of 76 cow-calf operations were sampled in 24 states (Central, n = 17; East, n = 30; West, n = 29), with herd sizes ranging from 10 head to more than 5,000 head. Observations occurred during processing of either cows or yearling heifers through a cattle chute restraint system, regardless of procedure being performed. With herds less than 100 head, all cows or yearling heifers were observed as they moved through the single file alley, into the chute, and upon exiting the chute for a distance of three body lengths. On operations greater than 100 head, a maximum of 100 contiguous head were observed. Results indicate that most participants were BQA trained (70%) and had crossbred herds (63%) with a Docile temperament (57%) and had Daily Visual Contact with their herds (47%). The mean observations for Prod Use (18.1% ± 28.9), Miscatch (2.5% ± 5.1), and Fall (2.5% ± 4.2) exceeded the upper limit of BQA standards. The BQA threshold for Prod Use is 10%, Miscatch is 0%, and Fall is 2%. Vocalization (3.8% ± 7.6), Jump (7.5% ± 9.9), Run (7.7% ± 13.8), and Slip/Stumble (6.3% ± 9.1) were within BQA thresholds (5%, 25%, and 10% respectively). Prod Use had the greatest number of impacting factors including BQA status, Herd Size Group, Temperament, and Visual Contact while Miscatch, Vocalization, and Fall all had single impacting factors (Region, Temperament, Visual Contact, respectively). Visual Contact and Temperament had an association with the majority of outcomes. Future research should focus more in-depth on specific factors and the variety contained within and on the role of veterinarians in handling outcome frequencies.
Open Access
Economic approaches to allocation of life cycle environmental burdens between beef production systems and ecosystem services
(Colorado State University. Libraries, 2021) Haddix, Jilleen D., author; Dillon, Jasmine A., advisor; Ahola, Jason, committee member; Sheehan, John, committee member
Buck Island Ranch (BIR) is a cow-calf operation in central Florida that manages over 4,200 hectares of semi-native and improved pasture and produces over 2,000 calves each year. The operation has the unique distinction of being both a working ranch and a conservation site with extensive monitoring of everything from species diversity across taxa to nutrient dynamics in pastures and wetlands for the past 30 years. As a result of managing for profitable beef production and conservation, they provide key ecosystem services to their community through conservation oriented management practices. The primary goal of this project was to perform a cradle to farm gate life cycle assessment (LCA) of environmental impacts and resource consumption in the production of BIR live weight (LW) sold from the ranch. In addition, reproducible methods were developed for multi-functional allocation of environmental impacts between beef and conservation benefits. The LCA was conducted using four approaches to economic allocation of emissions between beef and ecosystem services: (1) allocate all emissions to beef; (2) multifunctional allocation using payments for conservation management practices through the USDA Conservation Stewardship Program (CSP); (3) multi-functional allocation using the "highest and best use" (HBU) price based on real estate evaluation of BIR land; (4) multi-functional allocation using conservation easement prices set by the USDA Agricultural Conservation Easement Program (ACEP). The results of the life cycle impact assessment were as follows: 1 kg LW leaving the farm gate to be sold used 322.22 L of water consumption, 43.97 m2 annual crop-eq, and 2.01 MJ energy surplus. The associated emissions were 12.27 kg CO2-eq/kg LW and 36.97 g N-eq/kg LW. When emissions were allocated between beef and ecosystem services, the impacts for beef were reduced 2% using the CSP approach, 39% using the HBU approach, and 42% using the ACEP approach.
Open Access
Evaluation of pregnancy rates following timed AI in beef heifers after synchronization of follicular waves using a 14-d controlled internal drug release insert, and the lifetime productivity of beef heifers conceiving to, or sired by, AI
(Colorado State University. Libraries, 2012) French, Jesse, author; Peel, Kraig, advisor; Holt, Timothy, committee member; Ahola, Jason, committee member; Whittier, Jack, committee member
Three studies were conducted to evaluate the efficacy of a timed AI (TAI) estrous synchronization protocol that used a 14-d controlled internal drug release (CIDR) insert and a GnRH injection on d 9 to force ovulation of potentially persistent follicles and induce a second wave of follicle growth. In the first study 710 yearling heifers across 4 locations were assigned to 1 of 3 treatments: 1) 14-d GnRH-9 heifers (n = 242) received CIDR (1.38 g progesterone) and 100 μg GnRH on d 0, 100 μg GnRH on d 9, and 50 mg PGF2α on d 14 concurrent with CIDR removal, 2) 14-d 6 h PG heifers (n = 233) were identical to 14-d GnRH-9 except that on d 14, 2 25 mg injections of PGF2α were given 6 h apart, and 3) 5-d CO-Synch + CIDR heifers (n = 235) received 100 μg GnRH and CIDR on d 9 and a single 25 mg PGF2α at CIDR removal. All 3 treatments received 100 μg GnRH with TAI at 72 ± 2 h after CIDR removal. The 14-d GnRH-9 TAI pregnancy rate (54.5%) did not differ (P = 0.57) from the 14-d 6h PG TAI pregnancy rate (53.6%). The TAI pregnancy rate of 14-d protocols combined was 54.1%, and was not different (P = 0.20) from the 5-d CO-Synch + CIDR TAI pregnancy rate of 46.4%. The following year 319 yearling heifers across 4 locations were assigned to 1 of 3 treatments: 1) 14-d GnRH-9 (n = 107; as described earlier), 2) 14-d PG (n = 107) was identical to 14-d GnRH-9 except instead of receiving GnRH on d 0 they received 25 mg of PGF2α and, 3) 5-d CO-Synch + CIDR (n = 104; as described earlier). All treatments received 100 μg GnRH at TAI 72 ± 2 h after CIDR removal. Heifers' ovaries (n = 120) were ultrasounded at 2 locations on d 0, 9, 14, and 17 of the estrous synchronization protocol to determine ovarian structures and response. The 14-d GnRH-9 TAI pregnancy rate (52.3%) was not different (P = 0.82) than 14-d PG (47.6%), nor was the TAI pregnancy rate of both 14-d treatments combined (50.0%) different (P = 0.66) from 5-d CO-Synch + CIDR (47.1%). Based on ultrasonography, the 14-d GnRH-9 treatment induced a second wave of follicular growth in 25.9% of heifers while 14-d PG heifers had larger (P = 0.01) follicle size on d 9 but did not reduce (P > 0.10) corpora lutea at TAI compared to 14-d GnRH-9 or 5-d CO-Synch + CIDR. That same year 453 heifers at another location were assigned to 1 of 3 treatments: 1) 14-d GnRH-9 (n = 150; as described earlier), 2) 14-d GnRH-7 (n = 150) received 100 μg GnRH and CIDR on d 0, 100 μg GnRH on d 7, 25 mg PGF2α on d 14 at CIDR removal, and 100 μg GnRH at TAI 63 ± 3 h after CIDR removal, and 3) 7-d CO-Synch + CIDR received 100 μg GnRH and CIDR on d 7, 25 mg PGF2α at CIDR removal, and 100 μg GnRH at TAI 63 ± 3 h after CIDR removal. Pregnancy rate to TAI of 14-d GnRH-9 (51.3%) was not different (P = 0.75) than 14-d GnRH-7 treatment (48.0%), nor was the TAI pregnancy rate of both 14-d treatments (49.6%) different (P = 0.83) from 7-d CO-Synch + CIDR (48.6%). These data indicate that the 14-d CIDR estrous synchronization protocol with d 9 GnRH produces comparable pregnancy rates to TAI compared to the industry utilized 5-d and 7-d CO-Synch + CIDR estrous synchronization protocols. However, the additional labor and pharmaceutical cost of handling heifers on d 9 raises the question whether it's a viable TAI estrous synchronization alternative. The final experiment evaluated the lifetime productivity of heifers conceiving to AI or natural service (NS), and heifers sired by AI vs. NS. Calving and breeding records (n = 6,693) at one location for 1,173 Angus females and were obtained from 1991 to 2010. Lifetime weight weaned, calves weaned, and revenue produced was determined and analyzed. Heifers that conceived to AI had greater (P < 0.0001) lifetime weight weaned, lifetime calves weaned, lifetime revenue, and greater (P < 0.05) average annual weaning weight than heifers that conceived to NS. There was no difference (P > 0.10) in average annual weaning weight, lifetime weight weaned, lifetime calves weaned, or lifetime revenue produced between heifers sired by AI or NS. Estrous synchronization and AI can be a valuable tool to produce replacement heifers that conceive earlier, and in doing so increase their lifetime productivity.
Open Access
Synchronizing follicular waves using 14 day CIDR insert protocols in beef cows and assessing reticulo-rumen temperature changes for detection of ovulation in dairy cows
(Colorado State University. Libraries, 2012) Giles, Ryan, author; Peel, Kraig, advisor; Whittier, Jack, advisor; Seidel, George, committee member; Ahola, Jason, committee member
In the first experiment, objectives were to determine the effectiveness of an extended controlled internal drug release (CIDR) insert estrus synchronization protocol to produce 2 follicular waves, induce cyclicity in anestrus cows, and evaluate the efficacy of a single 50 mg dose of prostaglandin F2α (PG) at CIDR removal. This experiment included 779 primiparous and multiparous lactating beef cows at 3 locations (n = 779) that were randomly assigned to 1 of 3 treatments. Cows in the 14-d 50 PG treatment received a CIDR (1.38 g progesterone) with 100 μg GnRH analogue im on d 0, 100 μg GnRH analogue im on d 9, and CIDR removal with 50 mg PG im on d 14. Cows in the 14-d 6 h PG treatment were assigned the same protocol as the 14-d 50 PG treatment except that 25 mg PG im was given on d 14, plus 25 mg PG im 6 ± 1 h later. Cows in the 5-day CO-Synch + CIDR (5-d CO-Synch) treatment, received a CIDR with 100 μg GnRH analogue im on d 9, CIDR removal with 25 mg PG im on d 14, and 25 mg PG im 6 ± 1 h after first PG injection. Cows in all treatments received 100 μg GnRH analogue im with TAI 72 ± 3 h after CIDR removal. Pregnancy status to TAI was determined by ultrasonography 37 to 40 d after TAI. Pregnancy rate to TAI was higher (P < 0.05) in 14-d 50 PG treatment than 14-d 6 h PG and 5-d CO-Synch treatments. In the following year, 2 experiments were conducted at 6 locations. Our objectives were to: 1) determine the efficacy of an extended CIDR protocol with 2 induced follicular waves, and 2) determine the ability of initiating the CIDR protocol with GnRH analogue (Factrel) or PG. In exp. one, 588 primiparous and multiparous lactating beef cows at 2 locations were randomly assigned to 1 of 3 treatments. Cows in the 14-d GnRH-9 treatment (n = 202) received the same treatment as the 14-d 50 PG as described earlier. Cows in the 14-d GnRH-7 treatment received a CIDR insert and 100 μg GnRH analogue im on d 0, 100 μg GnRH analogue im on d 7, and CIDR removal with 25 mg PG im on d 14. Cows in the 7-day CO-Synch + CIDR (7-d CO-Synch) treatment, received a CIDR insert and 100 μg GnRH analogue im on d 7, and CIDR removal concurrent with 25 mg PG im on d 14. Cows in all treatments received 100 μg GnRH analogue im with TAI at either 72 ± 3 h (14-d GnRH-9 treatment) or 63 ± 3 h (14-d GnRH-7 and 7-d CO-Synch treatments). Combined across all locations, pregnancy rates to TAI were not different (P > 0.05) between 14-d GnRH-9 (54.8%), 14-d GnRH-7 (54.4%), and 7-d CO-Synch (52.3%) treatments. In exp. two, 625 primiparous and multiparous lactating beef cows across 4 locations were randomly assigned to 1 of 3 treatments. Cows in the 14-d GnRH treatment (n = 205) received the same treatment as the 14-d 50 PG treatment described earlier. Cows in the 14-d PG treatment (n = 214) received the same treatment as 14-d GnRH cows except that 25 mg PG im was given on d 0 instead of GnRH analogue. Cows in the 5-day CO-Synch treatment (n = 206), received the same treatment as described previously. Cows in all treatments received 100 μg GnRH analogue im with TAI 72 ± 3 h after CIDR removal. Combined across all locations, pregnancy rates to TAI were higher (P < 0.05) in the 14-d PG treatment (70.4%) than both the 14-d GnRH (54.4%) and 5-d CO-Synch (53.5%) treatments. The final experiment assessed changes in reticulo-rumen temperature to detect ovulation in lactating dairy cows. Lactating dairy cows (n = 494) ≥ 46 days in milk at 1 location were enrolled in a standard presynchronization protocol which included 2 PG injections 14 d apart. Twelve d later, cows were enrolled in an ovulation synchronization protocol of 100 μg GnRH im (d -10), 500 μg cloprostenol im (d -3), and 100 μg GnRH im 48 h later. All cows received TAI 16 to 19 h after the second GnRH injection. Blood was collected throughout the synchronization period to determine cycling status, response to synchronization treatments, and ovulation around the time of TAI. Reticulo-rumen temperature (Trr) was recorded by temperature recording reticulo-rumen boluses administered to each cow via balling gun within 24 h of calving. Each Trr reading was recorded every time animals entered the milking parlor to establish a 7 d baseline. The single maximum Trr rise (°C) from baseline on d of TAI (TrrMAX) and the average of all (1 to 3) Trr readings on d of TAI (TrrAVG) were used for analysis of Trr change related to ovulation. Mean (± SE) TrrMAX rise from the baseline tended to be higher (P = 0.06) in ovulatory (n = 446; 0.180 ± 0.023°C) than anovulatory (n = 48; 0.094 ± 0.042°C) cows. Mean (± SE) TrrAVG was higher (P < 0.01) in ovulatory (0.064 ± 0.011°C) than anovulatory (-0.047 ± 0.046°C) cows. The use of changes in Trr in ovulatory cows has been validated to pinpoint animals that do in fact ovulate in an estrus synchronization protocol.

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Browsing Department of Animal Sciences by Author "Ahola, Jason, committee member"

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