Beef Cow-calf Research Articles

Influence of Prepartum Fat Supplementation on Subsequent Beef Cow Reproduction and Calf Performance

High fat range supplement (HFRS) and HFRS with lipid from soybean soapstock (HFRS-SPH; Consolidated Nutrition, Omaha, NE) were compared with a corn-soybean meal supplement (control). In Exp. 1, primiparous cows were individually fed the control supplement (n = 12), HFRS (n = 12), or HFRS-SPH (n = 10) for 62 ± 2 d prepartum. Heifer body condition score pre- and postpartum did not differ (P=0.78) among groups. Milk production was not influenced (P=0.15) by source of supplement. Somatic cell counts, however, tended to be less (P=0.07) in HFRS-supplemented heifers than in heifers fed the control supplement. At birth, calf body temperature (P=0.8), vigor (P=0.7), and BW (P=0.6), as well as BW gain through 90 d postpartum (P=0.6), did not differ among prepartum supplementation treatments. Plasma concentrations of linoleic acid were greater (P=0.02) in fat-supplemented heifers at 30 d prepartum and at calving compared with heifers on the control treatment; however, concentrations of plasma linoleic acid returned to levels comparable with those in control heifers by 30 d postpartum. Neither number of cows cycling by 90 d postpartum (P=0.15) nor length of the postpartum interval (P=0.25) differed among treatment groups. In Exp. 2, multiparous cows were pen-fed the control supplement (n = 49), HFRS (n = 47), or HFRS-SPH (n = 49) for 59 ± 2 d prepartum. Prior to parturition, cows fed the control supplement had better body condition scores (5.8 ± 0.1; P=0.004) than cows fed either commercial supplement (5.4 ± 0.1). Calf performance (P=0.7) and conception rates (P= 0.5) did not differ among treatments. Productivity of cows and calves was not improved with provision of supplemental fat prepartum.

Zufütterung von Getreide an männliche Kälber aus der Mutterkuhhaltung während der Weideperiode

Abstract. Title of the paper: Supplementation of grain to suckling beef calves during the grazing period A study on 65 beef cow-calf pairs was conducted to investigate the intake of a feed supplementation with grain and its interrelations to performance and behaviourial characteristics of suckling calves, as well as the development of body condition and milk yield of the dam. The intake of grain in the group receiving the supplementation (group B) was on average 2.7 kg/ calf/day during the grazing period. A substantial individual variation of feed intake from 1.8 kg to 7.7 kg grain/calf/day was determined. In this period, the daily gains and the weaning weights of the calves in group B were higher (15.4% resp. 7.4%). The advantage of the calves of the group B could be proven only in the second half of the grazing period. The supplementation of grain caused significantly lower suckling activities and grazing periods per day. Effects of a grain supplementation in the feeding of suckling calves on pasture could not be determined on both the body condition and the milk yield of the cows.

Potentially hazardous sulfur conditions on beef cattle ranches in the United States.

To analyze the sulfur content of water and forage samples from a geographically diverse sample of beef cow-calf operations in the United States and to estimate frequency and distribution of premises where forage and water resources could result in consumption of hazardous amounts of sulfur by cattle. Cross-sectional study. 709 forage samples from 678 beef cow-calf operations and individual water samples from 498 operations in 23 states. Sulfur content of forage samples and sulfate concentration of water samples were measured. Total sulfur intake was estimated for pairs of forage and water samples. Total sulfur intake was estimated for 454 pairs of forage and water samples. In general, highest forage sulfur contents did not coincide with highest water sulfate concentrations. Overall, 52 of the 454 (11.5%) sample pairs were estimated to yield total sulfur intake (as a percentage of dry matter) > or = 0.4%, assuming water intake during conditions of high ambient temperature. Most of these premises were in north-central (n = 19) or western (19) states. Results suggest that on numerous beef cow-calf operations throughout the United States, consumption of forage and water could result in excessively high sulfur intake. All water sources and dietary components should be evaluated when assessing total sulfur intake. Knowledge of total sulfur intake may be useful in reducing the risk of sulfur-associated health and performance problems in beef cattle.

Pre-colostral antibodies to Neospora caninum in beef calves following an abortion outbreak and associated fall weaning weights

Published reports have suggested that Neospora caninum infection may decrease milk production in dairy cows and affect rate of gain and feed efficiency in feedlot steers. This study examined whether there was an effect on the weaning weights of commercial beef calves. The outbreak involved a family-owned, 350-head cow-calf beef herd. Calves that developed antibodies to N. caninum during gestation were compared to calves with no evidence of infection. Blood samples were collected from calves before colostrum ingestion and from all cows after calving. Sera were analysed using a commercially available enzyme linked immunosorbent assay for N. caninum. Detailed individual calving records, birth, and weaning weights were available for all calves. Of the 180 samples collected from the cows and first-calf heifers after calving, 153 (85%) were positive for N. caninum. Seventy-five (67%) blood samples collected from 112 calves prior to colostrum ingestion also had positive antibody titres for N. caninum. Fall calf weights for calves with antibodies to N. caninum at birth were insignificantly different than those of calves with no antibodies (difference, -9.2 lb [-4.18 kg]; 95% CI, -31.3 to 12.8 lb), after adjusting for calf sex, dam age, calf birth weight, calf age at weighing, and sire group.

Elk Management Strategies and Profitability of Beef Cattle Ranches

Computer simulation was used to determine the effects of wild elk (Cervus elaphus) on available forage, cattle herd size, and ranch gross margin in southwestern Montana beef cow-calf production systems. Data collected from 5 southwestern Montana ranches were used to develop input parameters for bio-economic models of elk forage harvest and beef production. Input parameters described ranch resources, animal inventories, and animal management. Cattle herd size ranged from 241 to 1147 head. Elk numbers varied by season within ranch and ranged from 49 to 421 head. Ranches were simulated as currently managed with elk present and with 10, 20, 30, and 100% of the elk removed. Simulated management scenarios were replicated 10 times. Data from each ranch were analyzed by one-way analysis of variance. Cattle herd size, gross margin, and available forage significantly (P < 0.05) increased when all elk were removed; however, the magnitude of these effects differed among ranches. Removal of all elk permitted cattle herd size to increase from 7 to 32% across ranches. Annual costs of elk on the 5 ranches (i.e., increase in gross margin from elk removal) ranged from $5,949 to $21,152. On an AUM basis, elk costs ranged from $8.55 to $14.51. Three management alternatives were evaluated for their potential to recover elk costs: Montana's Block Management Program, coordinated exchange of forage use, and leasing of hunting access. For each ranch, at least one of these management strategies could recover all estimated costs of providing elk habitat. Elk can significantly reduce profits for cow-calf ranches in southwestern Montana. Elk impacts on beef enterprise profits are closely associated with efficiency of resource use by cattie-i.e., ranches with lower unit costs of production lose more gross margin by providing forage for elk compared to ranches with higher production costs. DOI:10.2458/azu_jrm_v55i2_torstenson

Efficiency differences in Kansas beef cow-calf production (2002)

Efficiency differences in Kansas beef cow-calf production (2002)

Elk management strategies and profitability of beef cattle ranches

Computer simulation was used to determine the effects of wild elk (Cervus elaphus) on available forage, cattle herd size, and ranch gross margin in southwestern Montana beef cow-calf production systems. Data collected from 5 southwestern Montana ranches were used to develop input parameters for bio-economic models of elk forage harvest and beef production. Input parameters described ranch resources, animal inventories, and animal management. Cattle herd size ranged from 241 to 1147 head. Elk numbers varied by season within ranch and ranged from 49 to 421 head. Ranches were simulated as currently managed with elk present and with 10, 20, 30, and 100% of the elk removed. Simulated management scenarios were replicated 10 times. Data from each ranch were analyzed by one-way analysis of variance. Cattle herd size, gross margin, and available forage significantly (P &lt; 0.05) increased when all elk were removed; however, the magnitude of these effects differed among ranches. Removal of all elk permitted cattle herd size to increase from 7 to 32% across ranches. Annual costs of elk on the 5 ranches (i.e., increase in gross margin from elk removal) ranged from 5,949 to 21,152. On an AUM basis, elk costs ranged from 8.55 to 14.51. Three management alternatives were evaluated for their potential to recover elk costs: Montana's Block Management Program, coordinated exchange of forage use, and leasing of hunting access. For each ranch, at least one of these management strategies could recover all estimated costs of providing elk habitat. Elk can significantly reduce profits for cow-calf ranches in southwestern Montana. Elk impacts on beef enterprise profits are closely associated with efficiency of resource use by cattie-i.e., ranches with lower unit costs of production lose more gross margin by providing forage for elk compared to ranches with higher production costs.

Economies of scale in Kansas beef cow-calf production (2002)

Cow-calf producers must learn to control those aspects of production that are under their management. Quantity of beef produced and the cost of maintaining the breeding herd from conception to weaning are two examples of variables over which an individual operator has control. Therefore, it is important for managers to know their cost of production and, in turn, the relationship of quantity produced to cost. Our study found that for a 1% increase in quantity of beef produced, total cost increased by only 0.88%, suggesting economies of scale.

Animal Health, Management, and Foodborne Pathogens in Beef Feedlots

The USDA's National Animal Health Monitoring System (NAHMS) has been conducting benchmark studies of the livestock industries since the late 1980's. Through 2001 there have been studies of swine (n=3), dairy (n=2), beef cow-calf (n=2), beef feedlot (n=2), catfish (n=l), layers (n=l), sheep (n=l) and equine (n=l).&#x0D; A stratified random sample of feedlot operations with at least 1000 head capacity in the 12 leading cattle feeding states1 was selected for participation in the Feedlot '99 study. Cattle from feedlots with 1000 head or more capacity in these 12 states accounted for 81.9% of fed cattle marketings for 1999. Operators of selected feedlots were contacted for a series personal interviews to collect information on health and management of cattle in their feedlot. In addition, operators were offered the opportunity to participate in activities that required the collection of water, feed or feces.

Marketing Veterinary Services to Small Beef Producers

I was in a three person mixed practice in DeWitt, Iowa for fifteen years and we were able to increase our revenue by 90% in the beef cow-calf portion of our practice from 1988 (start of Total Beef Herd Health Program) to 1997. I am quite certain that you can also increase your revenue by initiating some new cow-calf beef programs in your practice.&#x0D; The beef cow-calf enterprise has critical success factors, and you need to be involved in enhancing the probability of success in these critical success factors.&#x0D; Various studies show that the critical success factors include:6,71. Knowing your cost to produce 100 lb of beef.&#x0D; 2. Becoming a low-cost, high-profit producer.&#x0D; 3. Reducing feed cost for the cow herd.&#x0D; 4. Learning to optimize vs. maximize. Adding an extra pound of weaning weight is not always cost-effective.&#x0D; 5. Learning that herd improvement does not come from doing one thing 100% better, but from doing 100 things 1% better.&#x0D; As we look at the entire beef cow-calf enterprise, we can divide it into the following segments:• Herd Health• Fertility• Nutrition• Genetics• Environment• Records• MarketingWhile you as a practitioner surely don't need to be an authority in all these areas, if you want to enhance your business, you should find your areas of expertise and work in these areas.5

Prevalence of antibodies against Mycobacterium avium subsp paratuberculosis among beef cow-calf herds.

To estimate the prevalence of Mycobacterium avium subsp paratuberculosis infection among cows on beef operations in the United States. Cross-sectional seroprevalence study. Sample Population-A convenience sample of 380 herds in 21 states. Serum samples were obtained from 10,371 cows and tested for antibodies to M avium subsp paratuberculosis with a commercial ELISA. Producers were interviewed to collect data on herd management practices. 30 (7.9%) herds had 1 or more animals for which results of the ELISA were positive; 40 (0.4%) of the individual cow samples yielded positive results. None of the herd management practices studied were found to be associated with whether any animals in the herd would be positive for antibodies to M avium subsp paratuberculosis. Results suggest that the prevalence of antibodies to M avium subsp paratuberculosis among beef cows in the United States is low. Herds with seropositive animals were widely distributed geographically.

Produtividade e eficiência biológica de sistemas pecuários de cria diferindo na idade das novilhas ao primeiro parto e na taxa de natalidade do rebanho no Rio Grande de Sul

Foi avaliada por intermédio da simulação a produtividade e eficiência de sistemas de criação de bovinos de corte no Rio Grande do Sul diferindo na idade das novilhas ao primeiro parto (IP, anos) e na taxa de natalidade (TN): "Sistema Tradicional" (ST) IP=4; "Sistema Melhorado" (SM) IP=3; e o "Sistema Um Ano" (SU) IP=2. Em cada sistema foi avaliado o efeito da TN variando entre 50 e 90%. Foi usado um modelo estático determinístico. A resposta em produtividade e eficiência à redução na IP foi dependente da TN. No SM e SU foi determinada resposta curvilinear a aumentos na TN, atingindo uma produção máxima de 83,9 e 77,9 quilos de bezerro desmamado (BD)/ha com TN de 82,5 e 92,3%, respectivamente. No ST a resposta foi linear, com aumentos de 6,1 kg BD/ha a cada 10% de aumento na TN. O custo energético por quilo BD produzido diminuiu linearmente, na medida em que a TN aumentou.

Survey of Salmonella Serotypes Shed in Feces of Beef Cows and Their Antimicrobial Susceptibility Patterns

Salmonella prevalence on cow-calf operations was studied as a part of a national study of health and management of the U.S. beef cow-calf industry and was conducted as part of the National Animal Health Monitoring System. Within this study, the prevalence of Salmonella spp. shed in feces was determined. A total of 5,049 fecal samples were collected from 187 beef cow-calf operations each visited on a single occasion. The number of fecal samples collected per operation was predetermined based on herd size. Salmonellae were recovered from 1 or more fecal samples collected on 11.2% (21 of 187) of the operations. Overall 78 salmonellae representing 22 serotypes were recovered from 1.4% (70 of 5,049) of samples. Multiple serotypes were recovered from eight samples from a single operation. The five most common serotypes were Salmonella Oranienburg (21.8% of isolates), and Salmonella Cerro (21.8%), followed by Salmonella Anatum (10.3%), Salmonella Bredeney (9.0%), and Salmonella Mbandaka (5.1%). The most common serogroups identified were C1 (33.3%), K (21.8%), B (16.7%), and E (15.4%). Even though the recovery rate of salmonellae from fecal samples was very low, 43.6% (34 of 78) and 38.5% (30 of 78) of the isolates were among the 10 most common serotypes from cattle with clinical signs of disease or isolated from humans, respectively. The majority of the isolates (50 of 78; 64.1%) were recovered from fecal samples from two operations. All isolates were screened for resistance to a panel of 17 antimicrobics, and 87.2% (68 of 78) were susceptible to all of the antimicrobics. The resistant isolates were most commonly resistant to streptomycin (n = 9) and/or sulfamethoxazole (n = 9). Nine isolates showed multiple (≥2 antimicrobics) resistance most commonly to streptomycin and sulfamethoxazole (n = 6).

Beef Cow-calf Herd Biosecurity Practices

The literature contains little information on current biosecurity practices of beef cow-calf producers. The cow-calf industry is experiencing an increasingly global marketplace and increasing pressure to minimize antibiotic use and maximize food safety. In this climate, economical biosecurity programs may be an important component of an integrated production management program. Biosecurity programs may be efficiently integrated with Hazard Analysis Critical Control Point (HACCP)-like programs to control food quality and safety, and minimize antibiotic use. This analysis is based on a recent survey on the management and biosecurity practices of U.S. beef cow-calf producers. This analysis identifies current biosecurity practices of beef cow-calf producers, management adjustments to biosecurity risks, and opportunities for veterinary intervention to decrease herd disease risk and risk of quality and safety defects.

Biosecurity practices of beef cow-calf producers.

To evaluate biosecurity practices of cow-calf producers. Cross-sectional survey. 2,713 cow-calf operations were used in phase 1 of the study, and 1,190 cow-calf operations were used in phase 2. Producers were contacted for a personal interview between Dec 30, 1996 and Feb 3, 1997 regarding their management practices. Noninstitutional operations with 1 or more beef cows were eligible to participate in the study. Producers who participated in the first phase of the study and who had > or = 5 beef cows were requested to continue in the study and were contacted by a veterinarian or animal health technician who administered further questionnaires. All contacts for the second phase of the study were made between Mar 3, 1997 and Apr 30, 1997. Additional data on use of various vaccines, testing of imported cattle for brucellosis, Mycobacterium paratuberculosis, bovine viral diarrhea, and tuberculosis as well as potential for feed contamination were collected during the second phase of the study. Producers commonly engaged in management practices that increased risk of introducing disease to their cattle such as importing cattle, failing to quarantine imported cattle, and communal grazing. Producers inconsistently adjusted for the increased risk of their management practices by increasing the types of vaccines given, increasing the quarantine time or proportion of imported animals quarantined, or increasing testing for various diseases in imported animals. Cow-calf herds are at risk for disease exposure from outside sources when cattle are introduced to the herd, and producers do not always adjust management practices such as vaccination schedules and quarantine procedures appropriately to minimize this risk. Veterinary involvement in education of producers regarding biosecurity risks and development of rational and economical biosecurity plans is needed.

The effectiveness of doramectin pour-on in the control of gastrointestinal nematode infections in cow–calf herds

Two field studies were conducted in the USA to determine the efficacy of a single strategically-timed dose of doramectin pour-on in the control of gastrointestinal nematodosis in beef cow–calf herds and the resultant effects on calf productivity. One study was carried out between May and October 1996 in a spring-calving herd at a site located in Idaho (ID) and the other between January and July 1997 in a fall-calving herd at a site located in Mississippi (MS). In each study, cow–calf pairs were randomly allotted by sex of calf to pastures and one of two treatment groups (doramectin pour-on at the recommended dose rate of 500 μg/kg body weight or untreated control). There were four pasture replicates per treatment at each site. Each pasture contained 12 cow–calf pairs at the ID site and 15 cow–calf pairs at the MS site. Treatment was administered to cows and calves on 21 May 1996 (ID) or 23 January 1997 (MS). Following treatment, cow–calf pairs were assigned to their designated pastures where they remained until the calves were weaned 140 (ID) or 168 (MS) days later. Cow and calf fecal egg counts and calf body weights were recorded on treatment day and then at monthly intervals until study termination. Doramectin treatment reduced nematode egg output in cows and calves over the entire grazing season compared to untreated controls and resulted in calf weight gain improvements of 9.8 kg ( p=0.295) at the ID site and 17.4 kg ( p=0.0002) at the MS site.

Neospora caninum seroprevalence and associated risk factors in beef cattle in the northwestern United States

A Neospora caninum seroprevalence and risk factor survey of 2585 cows was conducted in 55 beef cow–calf herds located in five northwestern states of the USA. Blood samples were collected by private veterinary practitioners and management practices were surveyed using a mail questionnaire. Producers were randomly selected from those that employed these veterinarians to perform annual herd pregnancy examinations. Questions were asked about animal management, grazing and feeding, immunization and record keeping practices. Blood was collected from a systematically selected sample of cows in each herd, and age, origin, and pregnancy status were recorded. Blood samples were analyzed for antibodies against N. caninum antigen using a monoclonal antibody-based competitive inhibition (CI) ELISA. Overall seroprevalence was 24% and within herd seroprevalence ranged from 3 to 67% with a median of 19%. Within herd seroprevalence and mean inhibition percentage were different between the five states. Herds that managed their cows on range for summer grazing had lower seroprevalence than those that did not, while increased seroprevalence was associated with higher winter stocking density. Cows less than 3 years of age had higher CI ELISA inhibition percent values than cows greater than 6 years of age. No relationship was noted between serologic status and individual cow origin (purchased or raised), or pregnancy status at the time of sampling.

Risk factors for high herd level calf morbidity risk from birth to weaning in beef herds in the USA

We analyzed data from a national survey of beef cow–calf producers in the USA to quantify the effects of hypothesized risk factors on herd-level calf morbidity risk from birth to weaning. The analysis included 2490 herds from 23 states. Two stepwise logistic regressions were fit to identify factors associated with ≥10% morbidity. The first model included all herds dichotomized into high-morbidity herds with ≥10% morbidity and low-morbidity herds with <10% morbidity. The second model excluded herds with between 5 and 10% morbidity, and compared ≥10% morbidity with ≤5% morbidity. The risk of dystocia was categorized into five levels for analysis; all non-zero categories were associated with increased odds of being a high-morbidity herd compared to herds with no dystocia (OR=2.7–5.5). Having >70% of cows and heifers calves in confinement also increased the odds of being a high-morbidity herd (OR=1.8). The population attributable fractions for dystocia and confined calving for the model including all herds dichotomized at 10% morbidity were 0.41 and 0.11, respectively. The summary population attributable fraction for both factors was 0.46.

Effects of dystocia and confined calving on calf-morbidity rate from birth to weaning (2000)

An analysis was performed on data from a national survey of US beef cow-calf producers to quantify the effects of management factors on calf-morbidity risk from birth to weaning. The analysis included 2,490 herds from 23 states. A high calf-morbidity herd was defined as one with greater than 10% morbidity. The rate of dystocia in the herd was categorized into five levels. All dystocia levels were associated significantly with increased risk of being a high calf-morbidity herd. Having greater than 70% of cows and heifers calve in confinement also was associated with increased risk of being a high calf-morbidity herd. Approximately 40% of herds experienced high morbidity from the effect of dystocia and approximately 10% from the effect of confined calving. This analysis indicates that dystocia and confined calving are important factors in determining a herd’s calfmorbidity rate from birth to weaning.

Association of herd composition, stocking rate, and duration of calving season with fecal shedding of Cryptosporidium parvum oocysts in beef herds

Objective To evaluate the association of herd demographics, parturition variables, stocking rate, and rotational grazing practices with the probability of fecal shedding of Cryptosporidium parvum from beef cow-calf herds in California. Design Cross-sectional study. Sample Population 38 beef cow-calf operations. Procedure Fecal specimens were collected and examined for C parvum oocysts, using immunofluorescent microscopy. Association between various demographic and management factors and the probability of shedding C parvum were statistically evaluated. Results Adjusted for age and month of collection of a fecal sample, cattle from herds with a high number of young calves (≤ 2 months old) on the day of sample collection, a high stocking rate (No. of cattle/acre/mo), or a longer calving season were more likely to shed C parvum oocysts, compared with cattle from herds with fewer young calves, a lower stocking rate, or a shorter calving season. Cattle from herds with a higher number of older calves (&gt; 2 months old) on the day of sample collection were less likely to shed C parvum oocysts, compared with cattle from herds with fewer older calves. Using our multivariate model, rotational grazing systems or season of onset of calving were not associated with shedding status for C parvum oocysts. Conclusions and Clinical Relevance Reproductive management that would result in a shorter calving season and use of a lower stocking rate for cattle may be associated with reduced risk of C parvum shedding. Intensive rotational grazing systems and time of year for onset of calving season apparently have little effect on reducing prevalence of oocyst shedding. (J Am Vet Med Assoc 1999;215:1833–1838)