Plasma Biochemical and Haematological Changes in Steers of Different Temperament during Feedlotting

Correlations between liveweight gains and temperament during feedlotting (Voisinet et al., 1997) may be an indication that cattle of different temperament suffer different degrees of stress. This paper describes the effect of grouping into feedlot pens, cattle of good, poor and mixed (some good and some poor) temperament on blood parameters that are indicators of stress (Bennett et al., 1989). Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

Effect of Grouping Feedlot Steers by Temperament on Performance and Carcass Traits

Cattle temperament is correlated with liveweight gains during feedlotting (Voisinet et al., 1997) ie. cattle that are nervous and flighty (poor temperament) do not perform as well as those that are quiet and docile (good temperament). This experiment investigated the effect of grouping into feedlot pens cattle of good temperament, poor temperament and mixed (some good and some poor) temperament on average daily gain (ADG), body condition score (CS), feed conversion efficiency (FCE) and various carcase traits. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

Effects of Grouping Feedlot Steers with a Range of Flight Speeds on Liveweight and Temperament Changes

Poor temperament cattle that are nervous and flighty do not perform as well in feedlots as good temperament cattle that are quiet and docile (Burrow and Dillon, 1997). There are contradictory anecdotal reports from industry about the effect of mixing cattle of different temperament on subsequent performance and temperament. Supposedly the presence of a few docile cattle in a feedlot pen-group will have a ‘calming’ effect on flighty pen-mates or the presence of a few flighty animals will ‘upset’ a group of quiet cattle. These hypotheses were tested using data in the experiment described by Petherick et al. (2000) where cattle were grouped into feedlot pens of good temperament, poor temperament and mixed (some good and some poor) temperaments. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia.

Quality of handling and holding yard environment, and beef cattle temperament: 1. Relationships with flight speed and fear of humans.

Numerous tests have been used to measure beef cattle temperament, but limited research has addressed the relationship between such tests and whether temperament can be modified. One-hundred-and-forty-four steers were given one of three human handling and yarding experiences on six occasions during a 12-month grazing period post-weaning (backgrounding): Good handling/yarding, Poor handling/yarding and Minimal handling/yarding. At the end of this phase the cattle were lot-fed for 78 days, with no handling/yarding treatments imposed, before being transported for commercial slaughter. Temperament was assessed at the start of the experiment, during backgrounding and lot-feeding by flight speed (FS) and a fear of humans test, which measured the proximity to a stimulus person (zone average; ZA), the closest approach to the person (CA) and the amount the cattle moved around the test arena (total transitions; TT). During backgrounding, FS decreased for all treatments and at the end of backgrounding there was no difference between them. The rate of decline, however, was greatest in the Good group, smallest in the Minimal group with the Poor intermediate. In contrast, ZA was affected by treatment, with a greater reduction for the Good group than the others (P = 0.012). During lot-feeding, treatment did not affect FS, but all groups showed a decrease in ZA, with the greatest change in the Poor group, the least in the Good and the Minimal intermediate (P = 0.052). CA was positively correlated with ZA (r = 0.18 to 0.66) and negatively with TT (r = -0.180 to -0.659). FS was consistently correlated with TT only (r = 0.17 to 0.49). These findings suggest that FS and TT measure a similar characteristic, as do ZA and CA, but that these characteristics are different from one another, indicating that temperament is not a unitary trait, but has different facets. FS and TT measure one facet that we suggest is general agitation, whilst ZA and CA measure fear of people. Thus, the cattle became less agitated during backgrounding, but the effect was not permanently influenced by the quantity and quality of handling/yarding. However, Good handling/yarding reduced fearfulness of people. Fear of people was also reduced during lot-feeding, probably as a consequence of frequent exposure to humans in a situation that was neutral or positive for the cattle.

Local immune response against larvae of Rhipicephalus (Boophilus) microplus in Bos taurus indicus and Bos taurus taurus cattle.

Bos taurus indicus cattle are less susceptible to infestation with Rhipicephalus (Boophilus) microplus than Bos taurus taurus cattle but the immunological basis of this difference is not understood. We compared the dynamics of leukocyte infiltrations (T cell subsets, B cells, major histocompatibility complex (MHC) class II-expressing cells, granulocytes) in the skin near the mouthparts of larvae of R. microplus in B. t. indicus and B. t. taurus cattle. Previously naïve cattle were infested with 50,000 larvae (B. t. indicus) or 10,000 larvae (B. t. taurus) weekly for 6 weeks. One week after the last infestation all of the animals were infested with 20,000 larvae of R. microplus. Skin punch biopsies were taken from all animals on the day before the primary infestation and from sites of larval attachment on the day after the first, second, fourth and final infestations. Infiltrations with CD3+, CD4+, CD8+ and [gamma][delta] T cells followed the same pattern in both breeds, showing relatively little change during the first four weekly infestations, followed by substantial increases at 7 weeks post-primary infestation. There was a tendency for more of all cell types except granulocytes to be observed in the skin of B. t. indicus cattle but the differences between the two breeds were consistently significant only for [gamma][delta] T cells. Granulocyte infiltrations increased more rapidly from the day after infestation and were higher in B. t. taurus cattle than in B. t. indicus. Granulocytes and MHC class II-expressing cells infiltrated the areas closest to the mouthparts of larvae. A large volume of granulocyte antigens was seen in the gut of attached, feeding larvae.

Male traits and herd reproductive capability in tropical beef cattle. 1. Experimental design and animal measures

Research into the genetics of whole herd profitability has been a focus of the Beef Cooperative Research Centre for Beef Genetic Technologies over the past decade and it has been identified that measures of male reproduction may offer a potential indirect means of selecting for improved female reproduction. This paper describes the experimental design and provides a descriptive analysis of an array of male traits in Brahman and Tropical Composite genotypes managed under the medium to high stress, semi-extensive to extensive production systems of northern Australia. A total of 1639 Brahman and 2424 Tropical Composite bulls with known pedigrees, bred and raised in northern Australia, were evaluated for a comprehensive range of productive and reproductive traits. These included blood hormonal traits (luteinising hormone, inhibin and insulin-like growth factor-I); growth and carcass traits (liveweight, body condition score, ultrasound scanned 12-13th rib fat, rump P8 fat, eye muscle area and hip height); adaptation traits (flight time and rectal temperature); and a bull breeding soundness evaluation (leg and hoof conformation, sheath score, length of everted prepuce, penile anatomy, scrotal circumference, semen mass activity, sperm motility and sperm morphology). Large phenotypic variation was evident for most traits, with complete overlap between genotypes, indicating that there is likely to be a significant opportunity to improve bull fertility traits through management and bull selection.

Male traits and herd reproductive capability in tropical beef cattle. 2. Genetic parameters of bull traits

A total of 4063 young bulls of two tropical genotypes (1639 Brahman and 2424 Tropical Composite) raised in northern Australia were evaluated for a comprehensive range of production and reproduction traits up to 24 months of age. Prior to weaning, peripheral blood concentrations of luteinising hormone (LH) and inhibin were measured at 4 months of age. At weaning (6 months) blood insulin-like growth factor-1 (IGF-I) and flight time were recorded. Body composition traits of fat depth and eye-muscle area were determined by ultrasonography at 15 months of age when additional measurements of liveweight, hip height and body condition score were recorded. Bull breeding soundness was evaluated at similar to 12, 18 and 24 months of age when measurements of scrotal circumference, sheath score, semen mass activity, progressive motility of individual sperm and percent morphologically normal sperm were recorded. Magnitude of heritability and genetic correlations changed across time for some traits. Heritability of LH, inhibin, IGF-I and of 18-month scrotal circumference, mass activity, progressive motility and percent normal sperm was 0.31, 0.74, 0.44, 0.75, 0.24, 0.15 and 0.25, respectively, for Brahmans and 0.48, 0.72, 0.36, 0.43, 0.13, 0.15 and 0.20, respectively, for Tropical Composites. Inhibin and IGF-I had moderate genetic association with percent normal sperm at 24 months in Brahmans but low to negligible associations in Tropical Composites. Body condition score in Brahmans and sperm motility (mass and individual) traits in both genotypes had moderate to strong genetic correlation with percent normal sperm and may prove useful candidates for indirect selection. There is scope to increase scrotal circumference by selection and this will be associated with favourable correlated responses of improved semen quality in both genotypes. The lack of genetic antagonism among bull traits indicates that selection for improved semen quality will not adversely affect other production traits.

The integrity of sperm chromatin in young tropical composite bulls

Sperm chromatin fragmentation is associated with subfertility, but its relationship with age progression in young bulls is poorly understood. The objective was to assess sperm chromatin fragmentation during the early post-pubertal development of 20 tropical composite bulls, using a sperm chromatin structure assay (SCSA) and sperm-bos-halomax (SBH). Bulls were subjected to bull breeding soundness evaluation (BBSE) at mean ages of 13, 18, and 24 mo. Traits measured included liveweight (WT), body condition score (BCS) and scrotal circumference (SC). Semen samples were collected by electroejaculation and assessed for mass activity (MA), motility (Mot), concentration (conc), sperm morphology and chromatin fragmentation. Concentration (r = 0.34, P = 0.0076), Mot (r = 0.36, P = 0.0041) and percentage of morphologic normal sperm (percent normal sperm (PNS); r = 0.31, P = 0.0132) were positively correlated with age. The percentage of sperm with proximal droplets (PD) was negatively correlated with age (r = -0.28, P = 0.0348), whereas neither SCSA nor SBH results were significantly correlated with age. The percentage of sperm with chromatin fragmentation using SCSA was correlated with PNS (r = -0.53, P < 0.0001), the percentage of sperm with head abnormalities (r = 0.68, P < 0.0001) and the percentage of intact sperm (Int) with SBH (r = -0.26, P = 0.0456). In summary, for assessment of sperm chromatin fragmentation, samples could be equally collected at 13, 18 or 24 mo of age, as results did not vary with age. (c) 2012 Elsevier Inc. All rights reserved.

Observation of a novel babesia spp. in eastern grey kangaroos (macropus giganteus) in australia

The roles and epidemiological features of tick-borne protozoans are not well elicited in wildlife. Babesia spp. are documented in many domestic animals, including cattle, horses, pigs, dogs and cats. Three cases affecting eastern grey kangaroos are described. The kangaroos exhibited neurological signs, depression and marked anaemia, and microscopic examination of blood smears revealed intraerythrocytic piroplasms. One to seven intraerythrocytic spherical, oval, pyriform and irregularly-shaped parasites consistent with Babesia spp. were seen in the blood smears and the percentage of infected erythrocytes was estimated to be approximately 7% in each case. Data suggest that the tick vector for this kangaroo Babesia sp. is a Haemaphysalis species. For Case 2, ultrastructural examination of the erythrocytes of the renal capillaries showed parasites resembling Babesia spp. and 18 of 33 erythrocytes were infected. DNA sequencing of the amplified 18S rDNA confirmed that the observed intraerythrocytic piroplasms belong to the genus Babesia. The phylogenetic position of this new kangaroo Babesia sp. (de novo Babesia macropus), as a sister species to the new Australian woylie Babesia sp., suggests a close affinity to the described Afro-Eurasian species Babesia orientalis and Babesia occultans suggesting perhaps a common ancestor for the Babesia in kangaroos. © 2012 Australian Society for Parasitology.

Seminal plasma proteome of eletroejaculated Bos indicus bulls

The present study describes the seminal plasma proteome of Bos indicus bulls. Fifty-six, 24-month old Australian Brahman sires were evaluated and subjected to electroejaculation. Seminal plasma proteins were separated by 2-D SDS-PAGE and identified by mass spectrometry. The percentage of progressively motile and morphologically normal sperm of the bulls were 70.4±2.3 and 64±3.2%, respectively. A total of 108 spots were identified in the 2-D maps, corresponding to 46 proteins. Binder of sperm proteins accounted for 55.8% of all spots detected in the maps and spermadhesins comprised the second most abundant constituents. Other proteins of the Bos indicus seminal plasma include clusterin, albumin, transferrin, metalloproteinase inhibitor 2, osteopontin, epididymal secretory protein E1, apolipoprotein A-1, heat shock 70kDa protein, glutathione peroxidase 3, cathelicidins, alpha-enolase, tripeptidyl-peptidase 1, zinc-alpha-2-glycoprotein, plasma serine protease inhibitor, beta 2-microglobulin, proteasome subunit beta type-4, actin, cathepsins, nucleobinding-1, protein S100-A9, hemoglobin subunit alpha, cadherin-1, angiogenin-1, fibrinogen alpha and beta chain, ephirin-A1, protein DJ-1, serpin A3-7, alpha-2-macroglobulin, annexin A1, complement factor B, polymeric immunoglobulin receptor, seminal ribonuclease, ribonuclease-4, prostaglandin-H2 D-isomarase, platelet-activating factor acetylhydrolase, and phosphoglycerate kinase In conclusion, this work uniquely portrays the Bos indicus seminal fluid proteome, based on samples from a large set of animals representing the Brahman cattle of the tropical Northern Australia. Based on putative biochemical attributes, seminal proteins act during sperm maturation, protection, capacitation and fertilization.

Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model

Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intra-peritoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0 to 100 and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C. fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion.