PrP gene polymorphisms in Cyprus goats and their association with resistance or susceptibility to natural scrapie

In contrast to scrapie in sheep, the genetic basis of susceptibility to scrapie in goats is not well understood. To study the association of prion protein (PrP) alleles with susceptibility to scrapie in goats in Cyprus, the coding sequence of the caprine PrP gene was determined in 717 goats, including 218 scrapie positive animals. Several novel polymorphisms were detected, such as a novel octarepeat variant and a stop codon mutation. Amino acids at codons 146 and 154 were associated with susceptibility to goat scrapie. Animals heterozygous for serine (S) and aspartate (D) at codon 146 were significantly under-represented in scrapie positive animals and no positive animals were found that were homozygous for these amino acids at codon 146. These results might provide the basis for genetic control of scrapie in Cypriot goats.     

Epidemiological analysis of the cyprus anti-echinococcosis campaign I. The prevalence of Echinococcus granulosus in cypriot village dogs,the first dog-test period of the campaign June–December, 1972

The prevalence of Echinococcus granulosus in Cypriot dogs during the first dog-test period of the anti-echinococcosis campaign (June–December, 1972)_was described and analyzed by contingency table methods and stepwise multiple regression. Mean canine E. granulosus prevalence rates, dogs per person, infected dogs per person, and sheep and goats per dog were found to be higher in Turkish Cypriot villages than in Greek Cypriot villages. It was also observed that during the first dog-test period of the campaign, only one of 285 rural village slaughterhouses was located in a Turkish Cypriot village. Results of a step-wise regression analysis showed that animal husbandry, canine, ethnic and economic variables accounted for 23% of the variation in initial canine E. granulosus prevalence rates. The effects of multicollinearity and measurement error on the results of these analyses and deficiencies in the data were discussed.     

Estrus induction in anestrous mixed-breed goats using the “female-to-female effect”

A trial was conducted during the anestrous period in female goats to determine: (a) whether estrus can be induced in anestrous goats by administration of equine chorionic gonadotropic hormone (eCG) and PGF_2α under pen conditions and (b) whether these sexually active female goats can elicit sexual arousal in sexually inactive bucks. One hundred and fifteen pluriparous, nonlactating mixed-breed female goats were randomly assigned to one of four treatment groups: (1) administration of a single dose of 240 IU of eCG, 50 μg PGF_2α i.m., and 25 mg progesterone (P₄) (eCG; n?=?30); (2) administration of P₄ and exposure to female goats treated with eCG–PGF_2α (P₄; n?=?39); (3) administration of 0.5 ml saline and P₄ (Sal; n?=?23); and (4) P₄ plus exposure to female goats treated with saline (Con; n?=?23). After hormone administration, all goats were put together with adult sexually inactive bucks for 15 days. The percentage of goats in estrus during these 15 days was similar in eCG-treated animals and untreated animals exposed to the eCG animals (97 and 95 %). Pregnancy rate was also similar (63 vs. 64 %) between these two groups. eCG-treated goats exhibited estrus earlier (P?<?0.05) than the treated goats in contact with the eCG goats. Furthermore, eCG-treated goats had larger litters (1.9?±?0.2 vs. 1.6?±?0.1, P?<?0.05) than the untreated goats in contact with the eCG goats. These results show that fertile estrus can be induced in anestrous female goats by exposing them to female goats induced to estrus with eCG. This female–female interaction triggers the stimulation cycle leading to the sexual arousal of bucks.     

The incidence of adult and larval stage Taenia hydatigena in Uttar Pradesh (India)

A total of 1023 dogs of different breeds from different parts of Uttar Pradesh State were examined for the presence of Taenia hydatigena, and 810 sheep, 1015 goats and 1040 pigs were examined for the presence of Cysticerus tenuicollis, to determine the incidence of these parasites. In dogs, the incidence of T. hydatigena was found to be 40.95%. The rate of infection was higher in street dogs than in dogs kept indoors.Cysticercus tenuicollis was found in 37.03% of sheep, 27.29% of goats and 8.30% of pigs. The rate of infection was higher in sheep than in goats or pigs. A high incidence of infection was found in the rainy season. The intensity of infection was higher in old than in young animals.     

State-of-the-art review of goat TSE in the European Union, with special emphasis on PRNP genetics and epidemiology

Scrapie is a fatal, neurodegenerative disease of sheep and goats. It is also the earliest known member in the family of diseases classified as transmissible spongiform encephalopathies (TSE) or prion diseases, which includes Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy (BSE), and chronic wasting disease in cervids. The recent revelation of naturally occurring BSE in a goat has brought the issue of TSE in goats to the attention of the public. In contrast to scrapie, BSE presents a proven risk to humans. The risk of goat BSE, however, is difficult to evaluate, as our knowledge of TSE in goats is limited. Natural caprine scrapie has been discovered throughout Europe, with reported cases generally being greatest in countries with the highest goat populations. As with sheep scrapie, susceptibility and incubation period duration of goat scrapie are most likely controlled by the prion protein (PrP) gene (PRNP). Like the PRNP of sheep, the caprine PRNP shows significantly greater variability than that of cattle and humans. Although PRNP variability in goats differs from that observed in sheep, the two species share several identical alleles. Moreover, while the ARR allele associated with enhancing resistance in sheep is not present in the goat PRNP, there is evidence for the existence of other PrP variants related to resistance. This review presents the current knowledge of the epidemiology of caprine scrapie within the major European goat populations, and compiles the current data on genetic variability of PRNP.     

Effects of Supplementation on Juniper Intake by Goats

The potential for winter supplementation to increase juniper intake by goats on rangelands in the Edwards Plateau region of Texas was assessed in two experiments. The first experiment evaluated the effect on juniper intake of either no supplementation (negative control) or supplementation with corn, alfalfa, or cottonseed meal fed at an isonitrogenous protein level of 1.5 g · kg body weight^-1 for 12 days. Redberry juniper (Juniperus pinchotii Sudw.) consumption by individually penned Spanish, Boer × Spanish, Spanish × Angora, and Angora goats was measured on days 11 and 12. Each goat received each supplement in a complete 4 × 4 Latin square design. Juniper intake increased for goats supplemented with alfalfa and cottonseed meal (P = 0.001), but not for those supplemented with corn (P = 0.944). Boer × Spanish goats did not differ in levels of consumption (P = 0.085) from the other breeds. A second study investigated the effect of either no supplementation or soybean meal supplementation on juniper consumption by free grazing Angora and Boer × Spanish goats. Forty goats were assigned to four pasture groups by breed and previous juniper intake, and randomly allocated to either the treatment (supplementation) or control (no supplementation) regime in a complete block design. After 4 days of grazing and supplementation, fecal samples were collected to estimate percent of juniper in the diet using near-infrared spectroscopy. Goats were then rotated to another pasture. Juniper intake was highest for goats supplemented with soybean meal (P = 0.034). Breed of goat did not affect intake (P = 0.240). Goats previously categorized as high juniper consumers based upon prior measurements of juniper intake ate more juniper (P = 0.003) than those classified as low consumers. This research indicates that the effectiveness of goats for biological control of juniper can be improved with a high protein, low starch supplement.     

Environmental enrichment and social rank affects the fear and stress response to regular handling of dairy goats

Human–animal interactions can have result in fear and stress for the animals and can affect negatively their welfare and productivity. Environmental enrichment techniques can be a tool to reduce this fear response to handlers. The aim of this study was to analyze the effects of environmental enrichment and social rank on fear and stress response to handling of dairy goats. Thirty Saanen dairy goats (3.5-5 years of age) were observed 6 hours daily for 16 consecutive days. Behavior sampling was used to record all events of agonistic interactions, and index of success was calculated for each goat. Two groups, control (CO) and enriched (EN), of 12 goats each (6 high rank [HR] and 6 low rank [LR]), were then observed during a 4-phase handling test. Reactivity behaviors were recorded using focal sampling, and plasma cortisol was assessed in all goats. An analysis of variance (ANOVA) was used to assess the effect of treatment (EN and CO) and social rank (HR and LR) on behavior, and a multivariate ANOVA for repeated measures was used to assess the effect of treatment and social rank on cortisol levels in response to handling. The EN group and HR goats had a longer distance to the handler (P < 0.01 and P < 0.05, respectively); however, it took longer for the goats in the CO group to be caught (P < 0.01). LR goats in the EN group showed higher levels of aggression to the handler than HR goats in the EN and CO groups as well as LR goats in the CO group (P < 0.01). On average, EN goats had higher cortisol values than in the CO (P < 0.05), and the HR goats had significantly higher cortisol values than the LR animals (P < 0.05). In general, goats in the EN group had a more excited reaction than the CO group that could be related to a cognitive state derived from the effect of the enrichment. These results have important implications for animal husbandry and help to broaden the literature on the effects of environmental enrichment and dominance rank on goat handling.     

Detection of <Emphasis Type="Italic">Trypanosoma vivax</Emphasis> DNA in semen from experimentally infected goats

The present work aimed to investigate the presence of T. vivax DNA in the semen of experimentally infected goats. Twelve male goats native to the Brazilian Northeast, adults, were randomly assigned to two experimental groups: the infected group consisting of six goats infected intravenously with 0.5 mL of blood containing approximately 1.25?×?10⁵ trypomastigotes of T. vivax, and a control group composed of six uninfected goats. After the infection, clinical examinations aiming to evaluate rectal temperature, parasitemia and hematocrit were performed. Semen samples were collected from goats by electroejaculation on the 7th, 14th and 21st days post-infection (dpi). The recombinant DNA-encoding gene encoding the L-like-specific gene for T. vivax. The infection was characterized by increased rectal temperature, high parasitemia and significant reduction of hematocrit values. Results for T. vivax DNA detection using TviCatL-PCR were positive in all semen samples from the infected group collected on 7th, 14th and 21st dpi. The presence of T. vivax DNA in 7th dpi suggests the early invasion of the parasite in the reproductive organs. Also, the finding of T. vivax DNA in all periods analyzed may suggest the continued elimination of the parasite in the semen, which may increase the chances of sexual transmission. Thus, T. vivax DNA is recorded for the first time in the semen of infected goats. Thus, these data are of great importance, since the detection of the T. vivax genetic material in the semen may point to the possibility that the parasite may be transmitted through the sexual pathway.     

The prevalence and pathogenicity of Chorioptes bovis (Hering, 1845) and Psoroptes cuniculi (Delafond, 1859) (Acari: Psoroptidae) infestations in feral goats in New Zealand

Between October 1976 and January 1980 a total of 368 feral goats was examined in New Zealand for the presence of Chorioptes bovis and 434 for the presence of Psoroptes cuniculi. The seasonal pattern of C. bovis infestation in feral goats was similar to that seen in sheep and cattle. The prevalence of infestation reached 100% in July and August (winter) and declined to 27% in February and March (summer). Fewer goats were infested with P. cuniculi and prevalence of infestation reached a maximum of 41% in July. No goats were found infested in the December and January samples. Chorioptes bovis infestation was independent of the age and sex of hosts. Infestation with P. cuniculi was independent of the sex of the hosts, but older goats were more frequently infested (16%) than younger goats (8.6%). Unilateral infestation with P. cuniculi was more common (74.5%) than bilateral infestation. No severe lesions were associated with C. bovis, but 21.3% of goats with P. cuniculi had the external auditory meatus blocked by waxy material and 12.8% had scabby encrustations on the ears. The importance of goats as a possible source of infestation to domestic animals is discussed.     

Association of SNP variants of MHC Class II DRB gene with thermo-physiological traits in tropical goats

Host defense in vertebrates depend on many secreted regulatory proteins such as major histocompatibility complex (MHC) class II which provide important regulatory and effector functions of T cells. Gene polymorphism in the second exon of Capra-DRB gene in three major Nigerian goat breeds [West African Dwarf (WAD), Red Sokoto (RS), and Sahel (SH)] was analyzed by restriction fragment length polymorphisms (RFLP). Four restriction enzymes, BsaHI, AluI, HaeIII, and SacII, were utilized. The association between the polymorphic sites and some heat tolerance traits were also investigated in a total of 70 WAD, 90 RS, and 50 SH goats. Fourteen different types of alleles identified in the Nigerian goats, four of which were found in the peptide coding region (A57G, Q89R, G104D, and T112I), indicate a high degree of polymorphism at the DRB locus in this species. An obvious excess (P?<?0.01) of non-synonymous substitutions than synonymous (dN/dS) in this locus is a reflection of adaptive evolution and positive selection. The phylogenetic trees revealed largely species-wise clustering in DRB gene. BsaHI, AluI, HaeIII, and SacII genotype frequencies were in Hardy-Weinberg equilibrium (P?>?0.05), except AluI in RS goats and HaeIII in WAD goats (P?<?0.05). The expected heterozygosity (H), which is a measure of gene diversity in the goat populations, ranged from 0.16 to 0.50. Genotypes AA (BsaHI), GG, GC and CC (AluI) and GG, GA, AA (HaeIII) appeared better in terms of heat tolerance. The heat-tolerant ability of SH and RS goats to the hot and humid tropical environment of Nigeria seemed better than that of the WAD goats. Sex effect (P?<?0.05) was mainly on pulse rate and heat stress index, while there were varying interaction effects on heat tolerance. Variation at the DRB locus may prove to be important in possible selection and breeding for genetic resistance to heat stress in the tropics.     

Studies into the prevalence of Mycoplasma species in small ruminants in Benue State,North-central Nigeria

The indicative prevalence of respiratory Mycoplasma species in small ruminants (SR) was determined in North-central Nigeria. Nasal swabs from 172 sheep and 336 goats from the Northeast, Northwest and South Senatorial Districts of Benue State were examined. Initial Mycoplasma isolation used Mycoplasma culture techniques followed by digitonin sensitivity testing. Species identification was done using polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Overall, Mycoplasma organisms were isolated from 131 (25.8 %) of the 508 SR examined. Prevalence rates of 18.1 and 29.8 % were recorded for sheep and goats, respectively. A total of 135 isolates of Mycoplasma belonging to three different species were identified: Mycoplasma ovipneumoniae (127), Mycoplasma arginini (7) and Mycoplasma mycoides subspecies capri (1). More than one Mycoplasma species were detected in four (3.1 %) of the 131 confirmed Mycoplasma positive cultures. Mycoplasma was isolated from 16.2 and 29.1 % of animals with and without respiratory signs, respectively. The high isolation rate of mycoplasmas in apparently healthy and clinically sick sheep and goats in this study indicates a carrier status in these SR which may constitute a serious problem in disease control.     

Effects of Stocking Rate and Heather Supplementation on Gastrointestinal Nematode Infections and Host Performance in Naturally-Infected Cashmere Goats

The aim of this study, performed on 62 adult dry cashmere goats grazing upland perennial ryegrass–white clover pastures and naturally infected with gastrointestinal nematodes, was to investigate the effects of stocking rate (SR: 24 vs. 38 goats · ha^-1) and tannin-containing heather supplementation (H: Calluna vulgaris [L.] Hull, Erica spp.) vs. nonsupplementation on parasite burden, fecal egg counts (FEC), and live weight (LW) changes. Goats were randomly assigned to four treatments in a 2 × 2 factorial arrangement and grazed continuously from May to October. Six goats per treatment were slaughtered at the end of the grazing period, and adult worms in the abomasum and small and large intestines of each animal were recovered, counted, and identified. FEC was affected by SR (P < 0.01) but not by H. However, the SR × H interaction was significant (P < 0.05). FEC increased (P < 0.001) along the grazing season in all treatments, and the SR × time interaction was significant (P < 0.001). In general, mean total worm counts in abomasum and small intestine tended to be higher under high SR, although the differences were only significant (P < 0.01) in Trichostrongylus spp. counts. In goats managed under the high SR, the mean of total Teladorsagia circumcincta counts was lower (P < 0.01) in supplemented animals, but no differences were recorded for Trichostrongylus spp., Chabertia ovina, Oesophagostomum columbianum, and Trichuris ovis. The goats gained more LW (P < 0.001) under low SR and when they were heather-supplemented. No significant SR × H interaction was found for LW change. In conclusion, high stocking rate increases the infectivity risk of pasture and the supplementation of grazing goats with heather contributing to improve animals' performance. Notwithstanding, the effect of heather availability on nematode FEC reduction could be highly dependent on the climatic conditions.     

Diet Quality Modifies Germination of Dichrostachys cinerea and Acacia nilotica Seeds Fed to Ruminants

The pods of many woody plants form an important part of the diet of livestock during the dry season due to their high nutritive value. However, the dispersal of seeds that remain intact and can potentially germinate after excretion is of particular concern when animals consume seeds of encroaching or invasive woody plants. The objectives of this study were to determine the effects of animal species in two experiments (experiment 1: goats, sheep; experiment 2: goats, cattle), diet quality (Medicago sativa hay, Digitaria eriantha hay) and seed characteristics (size, hardness) on the effectiveness of animal seed dispersal and germination of Dichrostachys cinerea and Acacia nilotica seeds. Owing to a limitation on the availability of seeds, the two experiments were done separately at different times. Each animal in both experiments received 1 000 A. nilotica seeds and 1 000 D. cinerea seeds mixed with either a low-quality diet (D. eriantha hay) or a high-quality diet (M. sativa hay). In experiment 1, we found a significant interaction effect of animal species (goats, sheep), diet (high-quality hay, low-quality hay), and seed species (A. nilotica seeds, D. cinerea seeds) on germination (P < 0.0001). There was also a higher seed recovery (P < 0.009) when animals were offered high-quality hay (47.4% ± 4.65) compared to low-quality hay (30.2% ± 3.24). In experiment 2, animal species affected seed recovery (P < 0.0325; goats 32.0% ± 6.44; cattle 50.3% ± 4.27) and germination percentage (P < 0.055; goats 14.1% ± 1.48; cattle 9.3% ± 0.94). The diet quality fed to the animals may affect dispersal and germination. However, animal species and seed characteristics also had important effects on germination of D. cinerea and A. nilotica seeds. Thus, all three of these factors play a major role in dissemination of viable seeds.     

Gastrointestinal nematode infection does not affect selection of tropical foliage by goats in a cafeteria trial

It is important to determine whether gastrointestinal nematodes (GINs) affect foliage choice of goats leading to confirm the expression of a self-medication behavior. This study investigated the effect of GIN infection on tropical foliage selection by goats. During experimental stage 1 (10 days), goats had a natural mixed GIN infection, and at stage 2 (10 days), goats were treated with effective anthelmintics to maintain them free of GIN infection. During stage 1 the twelve adult goats (32?±?2.3 kg live weight [LW]) were assigned to three groups (n?=?4) according to their initial GIN infection status: HI group, with fecal egg count (FEC) between 1450 and 2150 eggs per g/feces (EPG); MI group, medium FEC (592–1167 EPG); and the NI group, free from GIN infection. Fresh foliage of four tropical plants were offered to goats ad libitum for 1 h daily: Gymnopodium floribundum (high condensed tannin [CT] content, 37–40 %), Mimosa bahamensis (medium CT content, 16–17 %), Leucaena leucocephala (low CT content, 3–5 %), and Viguiera dentata (negligible CT content, 0.6–0.9 %). Jacobs’ selection indexes (JSIs) were estimated for the experimental foliage based on dry matter (DM), CT, or crude protein (CP) intake. During both study stages, individual fecal egg counts were estimated. The JSI patterns of different plant species, based on DM, CT, or CP, were similar irrespective of infection level during stage 1 (HI, MI, and NI) or no GIN infection (stage 2). Thus, irrespective of GIN infection, goats actively selected M. bahamensis (high CT, low CP content) and V. dentata (negligible CT, high CP content) but avoided G. floribundum (high CT, low CP content) and L. leucocephala (medium CT and high CP content). Thus, natural GIN infection did not influence goats’ foliage selection.     

Feeding Redberry Juniper (Juniperus pinchotii) at Weaning Increases Juniper Consumption by Goats on Pasture

Redberry (Juniperus pinchotii Sudw.) and ashe (Juniperus ashei Buchh.) juniper dominate rangelands throughout central Texas. Our objective was to attempt to improve the efficacy of goats as a biological control mechanism for juniper through behavioral training. Conditioning sheep and goats to increase the palatability of chemically defended plants can be a useful tool in brush control. Previous research illustrated that goats can be conditioned to consume more juniper while in individual pens when foraging choices are limited. To test whether this creates a longer-lasting increase in juniper preference, we determined if goats would continue to consume juniper on pasture for one year after being fed juniper in individual pens for 14 d. Female Boer-cross goats (n = 40) were randomly divided into two treatments: conditioned and naive to juniper. At approximately 12 mo of age, conditioned goats were placed in individual pens and fed redberry juniper 1 h daily for 14 d, while naive goats received only alfalfa pellets to meet maintenance requirements. After the pen-feeding phase of the study, goats were placed in one of four pastures (10 goats · pasture^?1) for 12 mo. Two pastures housed conditioned goats, and two pastures housed naive goats at a moderate stocking rate (1 animal unit · yr^?1 · 8 ha^?1). Bite count surveys were conducted twice per month, while herbaceous standing crop and monoterpene levels were measured once per month. Juniper preference varied monthly; however, conditioned goats consistently ate more (P < 0.05) juniper than naive goats except for April, when the study began, and March, when the study ended. When selection of herbaceous forages decreased, conditioned goats increased selection of juniper, while naive goats increased selection of other palatable shrubs. Seasonal changes of monoterpene levels in juniper had no apparent effect on juniper preference. We contend that feeding juniper at weaning will increase use of the plant in grazing situations.     

Comparison of effect of high intake of magnesium with high intake of phosphorus and potassium on urolithiasis in goats fed with cottonseed meal diet

The effect of high intake of Mg on urolithiasis was compared with high intake of P and K in goats being fed with a cottonseed meal and rice straw diet. Eighteen wether goats were randomly allocated into group A, B and C evenly and fed with cottonseed meal and rice straw diet for three months. From day 60 onwards, KH₂PO₄ and K₂HPO₄ were provided via drinking water to goats in group B to increase the intake of P, K, and MgO to goats in group C to increase the intake of Mg. Blood and urine samples were collected to analyze the concentration of P, K, Mg and Ca, and the activity product (AP) of potassium magnesium phosphate (MKP) in urine was also calculated. The composition of calculi and urinary sedimentary crystals were examined by chemical qualitative analysis, X-ray diffraction, X-ray energy dispersive spectrometry and Fourier transform infrared spectroscopy. The results showed that the incidence of urolithiasis in group C (6/6) was higher than that in group A (1/6) and B (1/6) (P < 0.05). The calculi were mainly composed of magnesium ammonium phosphate (MAP) and partly composed of MKP. MKP presented in crystals of different phases in this experiment. The high intake of Mg contributed to a significant increase of plasma Mg, but additional P, K did not cause a further increase of plasma P, K. Urine P, K, Mg and Ca and AP of MKP in group C decreased significantly after the onset of urolithiasis. In conclusion, high intake of Mg was more important in inducing struvite calculi compared with high intake of K and P in goats under these feeding conditions. Cottonseed meal and rice straw with additional Mg is a good dietary model for inducing struvite calculi in castrated goats.     

Epidemiological analysis of the Cyprus anti-echinococcosis campaign: II. The prevalence of hydatid cysts in slaughtered livestock,June–December, 1972

The distribution of livestock in Cyprus was described and analyzed by contingency table methods. Smaller numbers of sheep, goats and cattle were associated with Greek Cypriot villages. Sheep and goat densities were highest in Turkish Cypriot villages. Among the villages in which the slaughter of livestock was reported, the median percent prevalence of hydatid cysts was: 16.5% (range: 0–100%) in slaughtered sheep; 2.1% (0–100%) in slaughtered goats; 0.0% (0–100%) in slaughtered cattle; 0.0% (0–33%) in slaughtered pigs. The median numbers of livestock slaughtered in villages for the 6-month period were 45 sheep, 98 goats, 4 cattle and 32 pigs. The association between the prevalence of Echinococcus granulosus in the slaughtered sheep population (SHPPREV) of 254 villages of Cyprus and human, canine, and environmental factors, for the period June–December, 1972, was analyzed by step-wise multiple regression. Results showed that 25% of the total variation in SHPPREV was explained by 3 independent variables, total rainfall from the previous 6-month period (negatively correlated with SHPPREV), E. granulosus prevalence in dogs (positively correlated) and the percent village population composed of Turkish Cypriots (negatively correlated). Total rainfall from the previous 6-months period, alone, explained 19% of the total variation.     

Antibodies to Corynebacterium Pseudotuberculosis in Adult Goats from a Naturally Infected Herd

Serum samples taken in 3 successive years (1977, 1978 and 1979) from adult dairy goats (Norwegian breed) originating from 1 herd were examined for antibodies to Gorynebacterium pseudotuberculosis. Both bacterial agglutination test (BAT) and hemolysis inhibition test (HIT) were used. The proportion of seropositive goats increased 10–12 % during the investigation period. In 1979 all animals were seropositive to BAT and about 95 % had antihemolysins in their sera. Twenty-two of the 23 one-year old goats recruited to the herd in 1978 were seropositive. The average age-specific titres increased up to the age of 3 years, and subsequently decreased for goats aged 4–7 years. Caseous lymphadenitis is thus regarded as a chronic infection. The effect of age on the titre values was significant at the 5 % level in 1977 and 1978 when HIT was used and in 1978 when BAT was used. During the investigation period the same 36 and 40 goats were examined every year by BAT and HIT, respectively. Intermediate to high correlations between titre values for the same goats from year to year were found.Both BAT and HIT are suitable for sero-epidemiological investigations concerning infection with G. pseudotuberculosis in goats.     

Supplements Containing Escape Protein Improve Redberry Juniper Intake by Goats

Redberry juniper (Juniperus pinchotii Sudw.) is a common invasive plant species in west-central Texas. Goats will consume redberry juniper, but intake is limited by monoterpenoids found in the plant. Previous research has shown that goats will increase juniper intake through 1) conditioning and 2) protein supplementation. This study compared intake of juniper when goats received different protein supplements either with or without protein sources that are high in amino acids that escape digestion in the rumen. Recently weaned Boer-cross goats (n = 47) were randomly placed into five treatments. Treatments 1, 2, 3, and 4 received a protein supplement and juniper for 1 h daily for 14 d, along with a basal diet of alfalfa pellets (2% body weight). Treatment 5 received only a basal diet of alfalfa pellets and juniper. All supplements were formulated to be isonitrogenous (37% crude protein [CP]). Treatment 1 contained cottonseed meal (high CP escape value), treatment 2 contained cottonseed meal and distiller’s dried grain (higher CP escape value), treatment 3 contained soybean meal (low CP escape value), and treatment 4 contained soybean meal and distiller’s dried grain (moderate CP escape value). Refusals of juniper, supplements, and alfalfa were weighed daily to determine intake. Supplementation with 1) cottonseed meal, 2) soybean meal, or 3) soybean meal and distillers dried grain did not influence (P > 0.05) juniper intake. Conversely, goats supplemented with cottonseed meal and distiller’s dried grain ate more (P < 0.05) juniper than goats receiving only alfalfa, possibly because of increased escape of glucogenic amino acids. We contend that supplementation with feeds high in protein escape values should increase juniper intake on rangelands.     

Learning Through Foraging Consequences: A Mechanism of Feeding Niche Separation in Sympatric Ruminants

Explanations for why sympatric ruminant species select diets composed of different plant species or plant parts have been controversial. Our explanation is based on learning from foraging consequences, which includes the influences that morphology, physiology, and experience have on diet selection. We conducted a trial with cattle (Bos taurus), sheep (Ovis aries), and goats (Capra hircus) and leafy spurge (LS; Euphorbia esula L.) to explore the interface between the learning and morphophysiological foraging models with these sympatric ruminants. After a pretrial adjustment period, the control group for each species received, via stomach tube on days 1 and 2, ground grass after eating a novel food (NF; rolled corn), and the treatment group for each species received ground air-dried LS after eating the NF. NF intake on days 2 and 3 was expressed as a percent of NF intake on day 1, and it declined considerably for cattle and sheep dosed with LS but did not decline for goats receiving it (P = 0.001). LS elicited learned aversive feeding responses from cattle and sheep but not from goats. The results are consistent with field observations that goats graze LS more readily than sheep or cattle do. Learning from foraging consequences offers an explanation for the unique diets of sympatric ruminant species.