Diet Composition,Forage Selection,and Potential for Forage Competition Among Elk,Deer, and Livestock on Aspen–Sagebrush Summer Range

We evaluated elk (Cervus elaphus), mule deer (Odocoileus hemionus), cattle (Bos taurus), and domestic sheep (Ovis aries) diet composition, diet overlap, and forage selection on aspen (Populus tremuloides Michaux)–sagebrush (Artemisia spp. L.) summer range in northeastern Nevada to understand potential for forage competition to provide better information for managing these communities. Diets were determined through microhistological fecal analysis from 1998 to 2000, and forage selection was evaluated at feeding sites in aspen and sagebrush communities in 1999 and 2000. Elk spring diets were the most diverse in composition; summer elk diets were dominated by forbs (59%–78%); deer consumed mostly woody browse (64%–72%); and cattle and sheep ate mostly graminoids. Lupines (Lupinus spp. L.) constituted ≥ 11% of elk, deer, and sheep diets in summer. Spurred lupine (Lupinus caudatus Kellogg) was the lupine typically selected in feeding sites and greatest consumption occurred in summer when total alkaloid levels were lowest. Highest diet overlap was between cattle and sheep in 1999 (68%) and lowest between deer and cattle in 2000 (3%). Summer elk and deer diets overlapped moderately (45%–59%). Diets did not differ between elk in spring with sheep, elk in summer with deer and sheep, or cattle with sheep. Cattle foraged selectively on forbs in aspen communities (68%) and on graminoids in sagebrush communities (88%), reflecting relative forage availabilities. We detected no differences among elk, cattle, and sheep for forage selection in aspen communities. Electivity indices indicated elk preferred forbs in aspen and sagebrush communities; cattle preferred graminoids in sagebrush; and foraging sheep preferred forbs in aspen. Our results suggest potential for forage competition among ungulates on aspen–sagebrush summer range is highest for forbs in aspen communities. Monitoring productivity and use of key forage species, particularly forbs in aspen communities, should complement management objectives on shared aspen–sagebrush summer range.     

Diets containing conventional,naked and high‐amylose barleys for broilers

1. Samples of Glacier (Pentlandfield), North American Glacier and Nackta (naked) barleys contained 112, 123 and 118 g of protein per kg dry matter, respectively.

2. Substitution of Nackta for conventional feed‐grade barley allowed a decrease of 10 kg per Mg in the fish meal content of a broiler diet, without impairing bird performance.

3. Replacement of conventional barley by Glacier (Pentlandfield) high‐amylose barley significantly increased food intake and body weight of broiler chickens at 56 d of age.     

Laboratory test descriptions for bovine respiratory disease diagnosis and their strengths and weaknesses: Gold standards for diagnosis,do they exist?

The diagnosis of bovine respiratory diseases (BRD) poses significant challenges to the clinician as there are numerous infectious etiologies, operating singly or most often in combination. Clinical signs alone may not be diagnostic and the diagnostic laboratory is often used to assist the clinician. Recently many molecular-based tests have been taken from the research laboratory to the veterinary diagnostic laboratory. This review describes the “traditional tests” and several “molecular tests” and discusses the benefits and limitations of the tests and their interpretation. Clinicians should consult with their diagnostic laboratory regarding the interpretation of the test results. The rate of development and use of molecular diagnostic tests have outpaced validation, standardization, and standards for interpretation relative to their use in BRD diagnostics.     

Serological status of Canadian cattle for brucellosis,anaplasmosis, and bluetongue in 2007–2008

A national bovine serological survey was conducted to confirm that the prevalence of brucellosis, bluetongue, and anaplasmosis does not exceed 0.02% (95% confidence) in live cattle in Canada. Sampling consisted of a systematic random sample of 15 482 adult cattle slaughtered in federally inspected abattoirs, stratified by province. Samples were tested to detect antibodies for brucellosis, bluetongue, and anaplasmosis. All samples were negative for brucellosis. Three samples were seroreactors to bluetongue, 2 of which originated from the Okanagan Valley in British Columbia and 1 from Ontario, which after follow-up, was considered an atypical result. A total of 244 samples were seroreactors to Anaplasma and follow-up identified infection in Saskatchewan, Manitoba, and Quebec. In conclusion, the Canadian cattle population remains free of brucellosis and free of bluetongue outside the Okanagan Valley. Canada is no longer free of anaplasmosis and will be unable to claim freedom until eradication measures are completed.     

Spatial hierarchical variances and age covariances for seroprevalence to Leptospira interrogans serovar hardjo, BoHV-1 and BVDV for cattle in the State of Paraíba, Brazil

We estimated spatial hierarchal variances and age-group covariances for seroprevalence to Leptospira interrogans serovar hardjo (LeptoH), bovine viral-diarrhea virus (BVDV) and bovine herpesvirus type 1 (BoHV-1) among 2343 cattle from 72 properties sampled in the State of Paraíba, Brazil in 2000. From each property, eight animals in each of the four age categories were evaluated. The age categories studied were: pre-weaned (0–6 months), young (7–18 months), replacement (19–30 months) and mature (>30 months). Overall seroprevalence to LeptoH was 16.0% and showed clustering at all levels of the spatial hierarchy and had a high posterior probability of being negatively correlated between replacement and mature groups within herds. Seroprevalence to BoHV-1 was 46.6% and demonstrated very little clustering among levels of the spatial hierarchy and was positively correlated between young and replacement groups within herds. Seroprevalence to BVD was 22.2% and was strongly clustered within herds and was positively correlated between young and replacement age groups within herds.     

Seroprevalence and risk factors for leptospirosis in cattle,sheep, and goats at consorted rearing from the State of Piauí, northeastern Brazil

Leptospirosis is an endemic disease in Latin America, caused by pathogenic bacteria of the genus Leptospira. It is considered one of the main causes responsible for the negative economic impact on global livestock by causing reproductive problems. The research aimed to determine the prevalence of leptospirosis in cattle, sheep, and goats at consorted rearing in the micro-region of Teresina, Piauí state, northeastern Brazil, as well as to identify prevalent serovars and risk factors associated with seroprevalence. Serum samples were analyzed in 336 sheep, 292 goats, and 253 cattle using microscopic agglutination test (MAT). Overall, 378 samples were positive to MAT, with seroprevalence of 42.9%. The prevalences in cattle, sheep, and goats were 50.5, 40.5, and 34.6%, respectively. All herds presented at least one seropositive animal; the Hardjo/Wolffi serovar association was the most common in cattle and Icterohaemorrhagiae in goats and sheep. Beef production (OR?=?4.9), cattle herd over 35 animals (OR?=?4.0), feeding on pasture (OR?=?6.4), weir and/or stream as water source (OR?=?2.1), and no veterinary services (OR?=?2.9) were risk factors for cattle infection. For sheep, intensive management system (OR?=?5.3), suspended slatted facilities (OR?=?2.2), more than 20 sheep in reproductive age (OR?=?1.9), and absence of deworming (OR?=?3.5) were the risk factors, while for goats, the identified risk factors were sheep herd over 52 animals (OR?=?1.9) and no veterinary services (OR?=?1.8). We conclude that the infection was spreading in consorted herds in this region. Thus, it would be interesting and important to conduct educative activities to farmers on the economic impacts of this disease and the need of preventive and control strategies mainly focused on sanitary measures and animal handling.     

Tuberculosis prevalence and risk factors for water buffalo in Pará, Brazil

The prevalence of and possible risk factors for tuberculosis were studied in water buffalo from Pará, Brazil. In this study, 3,917 pregnant and nonpregnant female Murrah and Mediterranean buffaloes were studied; 2,089 originated from Marajó Island, and 1,108 were from the mainland. The comparative cervical tuberculin test was used as a diagnostic test for tuberculosis in these animals. The prevalence of positive buffaloes was 3.5 % (100/2,809) on Marajó Island and 7.2 % (80/1,108) on the mainland. The municipalities with the highest tuberculosis prevalence rates in animals were Ipixuna do Pará (10.1 %), Marapanim (9.8 %), Chaves (9.4 %), Paragominas (8.6 %), and Cachoeira do Arari (6.7 %). The tuberculosis prevalence was not significantly different between the Murrah (4.3 %) and Mediterranean (4.8 %) breeds or between pregnant (5 %) and nonpregnant (4.3 %) buffaloes. Tuberculosis was detected in water buffaloes from Pará, Brazil; the mainland buffalo exhibited the highest tuberculosis prevalence. These results indicate that this disease is dangerous to public health and buffalo farming in Pará.     

Genetic parameters for milk,growth, and reproductive traits in Guzerá cattle under tropical conditions

Tropical Animal Health and Production - This study aimed to estimate the genetic parameters of milk (305-day milk yield (MY305)), growth (weaning weight (WW), yearling weight (YW), and weight at...     

History,Location, and Species Matter: Insights for Human–Wildlife Conflict Mitigation From India

Preventing loss of crops, threats to livestock, damage to property, and human injury and death attributed to wildlife are conservation challenges. We surveyed over 5,000 households around 11 reserves in India to examine these issues and mitigation efforts. Crops were lost by 71% of households, livestock by 17%, and human injury and death were reported by 3% of households (losses attributed to 32 species). Households deployed 12 mitigation measures with nighttime watching, scare devices, and fencing used the most. A household’s conflict history (>20 years for livestock loss, 10–20 years for crop loss), proximity to reserves, and crops grown or livestock owned were associated with higher mitigation use. There were differences across reserves, with households in Rajasthan least likely to use mitigation. Crop protection (88%) was more likely than livestock protection (32%). Investments in conflict mitigation should consider the history, location, species, socioeconomic variations among households, and differences in regional policies.     

Leptospirosis seroprevalence and risk factors for sheep in Maranhão state,Brazil

This study was conducted to determine leptospirosis seroprevalence in sheep and their spatial distribution as well as identify risk factors associated with seropositivity in sheep from 37 herds and 11 municipalities in the Presidente Dutra microregion, Maranhão state, Brazil. We analyzed 379 blood serum samples using a Microscopic Agglutination Test (MAT). The individual seroprevalence was 32 %. Of the 37 herds studied, 30 (81 %, 95 % CI 69–94 %) had at least one seropositive animal. In seven municipalities, we observed infection in 100 % of the herds. The serovars recorded were Grippotyphosa (67 %), Wollfi with Hardjo (9 %), Bratislava (9 %), Hardjo (5 %), Icterohaemorrhagiae (5 %), Pomona (2 %), Castellonis (2 %) and Copenhageni (0.8 %). We concluded that the Leptospira spp. in sheep is widespread in the area of sheep farms in Maranhão state, and a risk factor is the animals' water source.     

Selection for food conversion in broilers: Direct and correlated responses to selection for body‐weight gain,food consumption and food conversion ratio

1. Direct and correlated responses were determined after five generations in four lines of chickens selected either for increased body‐weight gain (line W), for increased food consumption (line F), for decreased food conversion ratio (line E), or at random (line C).

2. Realised heritability estimates calculated after five generations of selection were : 0–37 + 0.04 for weight gain (WG); 0.44 + 0.05 for food consumption (FC); 0.21 + 0.04 for food conversion ratio (FCR).

3. Realised genetic correlation estimates were: WG and FC, +0.71 ±006; WG and FCR, ‐0.40±0.09; FC and FCR, +0.27 + 0.09.

4. Zero‐generation heritability and genetic correlation estimates were greater than the realised estimates, and sex linkage appeared to be important in the expression of all three traits.

5. The genetic correlation between FC and FCR was asymmetrical with considerable positive response in FCR in line F (r_g = +0.79) but negligible response in FC in line E (r_g = —0.01).

6. There was an apparent plateau in response in FCR in line E from the third to the fifth selected generations.     

Are Droppings,Distance From Pastoralist Camps,and Pika Burrows Good Proxies for Local Grazing Pressure?

Grazing is regarded as one of the most important factors influencing rangeland ecosystems. Many previous studies have used indirect measures (proxies) of grazing intensity, such as the distance from congregation areas and the number of herbivore excreta, to estimate effects of grazing on vegetation parameters in rangeland ecosystems. However, little is known about how such proxies reflect the true grazing intensity, and if their suitability is consistent across landscape conditions. We measured grazing intensity based on the amount of plant ramets being grazed in 75 plots positioned across a rangeland landscape in central Tibet. Several grazing intensity proxies (distance from pastoral camp sites, number of yak dung patches (old and fresh), sheep and goat dropping piles, and pika (Ochotona curzoniae) burrows (active and abandoned)) were also measured in each plot. Regression models were used to examine the suitability of these proxies in predicting our measure of real grazing intensity. None of the examined proxies satisfactorily predicted real grazing intensity in our study system. The distance from camp sites was the best proxy for grazing intensity (P<0.001), but it explained only 30% of its variation. Fresh yak dung and active pika burrows explained only 10% and 3% of the variation in grazing intensity, respectively. The suitability of using proxies for grazing intensity did not significantly differ along landscape parameters (elevation, aspect directions, and slope angle) (P>0.05), except that the number of animal excreta and pika burrows functioned better as proxies at low, compared to high, elevation (P<0.05). Our results should be of concern since many studies use proxies to estimate effects of grazing on vegetation dynamics and ecosystem properties. We recommend awareness of potential limitations and suitability of proxies, when real grazing intensity is not measured.