Comparison of Insulin Sensitivity of Horses Adapted to Different Exercise Intensities

Diets high in concentrates and soluble carbohydrates are associated with reduced insulin sensitivity in horses. Exercise training could protect against diet-induced insulin resistance. The objective of this study was to determine the intensity of exercise training required to affect insulin sensitivity in stabled horses fed a diet high in concentrates but moderate in soluble carbohydrates. In all, 31 stabled horses underwent three different exercise regimens: turnout, light exercise, and moderate exercise, while being fed a diet containing 60% concentrate. Blood was sampled monthly and analyzed for insulin. Insulin sensitivity was assessed using basal insulin concentrations and calculated insulin sensitivity (reciprocal of the square root of insulin) and compared across months by analysis of variance with repeated measures. Insulin sensitivity (reciprocal of the square root of insulin) was higher during periods of moderate and light physical activity as compared with turnout. These results indicate that turnout alone may not be adequate to improve insulin sensitivity in horses fed high amounts of concentrate.     

Efficacy of ivermectin against Dirofilaria immitis larvae in dogs 30 and 45 days after induced infection

Forty-two Beagles, 14 to 15 weeks of age, were injected subcutaneously with 50 infective larvae of Dirofilaria immitis and were allotted by weight, within sex, to 6 treatment groups. Group 1 served as nonmedicated vehicle-treated controls; groups 2 through 5 were given an oral tablet form of ivermectin at dosages of 0.3 micrograms/kg, 1.0 micrograms/kg, 2.0 micrograms/kg, and 3.3 micrograms/kg at 30 days after inoculation; group 6 was given the 2.0 micrograms/kg dosage at 45 days after inoculation. Dogs were euthanatized and necropsied 154 days after treatment (day 139 for dogs in group 6) and examined for heartworms. On the numerical bases of helminths recovered in the groups, the efficacies for preventing heartworm maturation were 0% (group 2), 53.2% (group 3), 97.2% (group 4), 98.1% (group 5), and 63.8% (group 6). Drug-related adverse reactions were not detected.     

用公猪刺激小母猪发情中的注意事项

许多猪场只是充分应用了现有的知识并注意了其细节 ,就提高了其小母猪的生产成绩     

Sexual performance of rams as determined by maturation and sexual experience

The purpose of this study was to compare the sexual performance of rams that differed in age (maturation) and sexual experience. Twenty-four ram lambs (8 mo of age) and 21 rams (20 mo of age) were individually exposed to four females in hormonally induced estrus for 30 min on five occasions, 7 d apart. Half (12) the ram lambs and nine of the yearlings were sexually naive at the start of testing (had been denied access to females since weaning); the remaining males were sexually experienced. The sexual performance of the virgin rams was poorer during the initial exposure to females than in subsequent tests, whereas the sexual behavior of the sexually experienced males did not change over the days of testing. Sexually naive ram lambs and rams exhibited an improvement in sexual performance between Tests 1 and 2; during Test 3 to 5 the sexual performance (ejaculations per test) of sexually naive and experienced rams was similar. The only effects of age (maturation) on sexual performance during the last three test days were a higher frequency of mounts without ejaculation plus mount attempts (P less than .03) and a greater number of mount interactions per ejaculation (P less than .02) by ram lambs. In conclusion, one or two relatively brief exposures to estrous females can bring the sexual performance of virgin rams up to levels comparable to that of experienced males. Also, ram lambs in good condition exhibit acceptable levels of sexual performance.     

Interbreed variation of DLA-DRB1, DQA1 alleles and haplotypes in the dog.

Although 36 DLA-DRB1 and 10 DLA-DQA1 allele sequences have been published to date, no data on individual allele frequencies exists, either for specific breeds or cross breeds, and the full extent of the polymorphism at each of these loci is still not known. We have used sequence-specific oligonucleotide probing (SSOP) to characterise a series of 367 dogs for their DRB1 and DQA1 alleles. These included individual animals from over 60 different breeds, with numbers per breed ranging from 1 to 39. DLA types were generated from 218 dogs for DRB1 and from 330 dogs for DQA1, while 181 dogs were characterised for both these loci. The frequency of individual DRB1 and DQA1 alleles showed considerable interbreed variation, e.g. 83% of West Highland White Terriers were DRB1*01 as opposed to 9% of Collies. No breed had >9 of the 22 DRB1 types defined in this study; several breeds had only two DRB1 types. DLA-DQA1 showed less variation in allele numbers per breed, but also showed considerable interbreed frequency variation. Haplotype analysis revealed over 44 different DRB1/DQA1 combinations. Of these, 25 were in a number of animals, and also in an animal that was homozygous for one or both of these loci. Some DRB1 alleles could be found in combination with several different DQA1 alleles, while others were only present in one haplotypic combination. DLA allele frequency data in normal dogs will be critical for disease association studies. It may also be possible to use haplotype data to establish the genetic relationships between different dog breeds.     

Effects of cereals and/or protein supplement extrusion on diet utilisation and performance of intensively reared cattle

The effect of extruding the cereal and/or the protein supplement of a compound feed on its nutritive value and on the performance of intensively reared male calves was studied. The compound feed was formulated with 0.65 of a cereal blend (60:40 maize:barley), 0.25 of a protein blend (1/3:1/3:1/3 raw soybeans:peas:lupins), and 0.08 of urea to contain 0.17 of crude protein. It was tested without extruding (NE) and with the cereal blend (CE), the protein blend (PE) or both (CPE) extruded. Another non-extruded compound feed with mainly soybean meal as the protein supplement (NE-SBM) also was studied. The five experimental compound feeds together with barley straw were offered ad libitum to 50 male Friesian calves (112 kg initial live weight) for 13 weeks, recording individual feed intake and live weight gain. Crude protein (CP) solubility and in vitro and in situ CP degradation of experimental compounds, and in vitro gas production kinetics, in vivo digestibility and urinary allantoin excretion of diets were determined. Cereal extrusion promoted a greater gas production at all incubation times (p < 0.001), associated to the increase in starch gelatinisation. PE and NE-SBM compounds showed lower in vitro (p < 0.01) and in situ (p < 0.001) CP degradability than the other feeds. Ingredient extrusion did not affect apparent DM, OM and CP digestibilities, but diet CPE showed a lower NDF digestibility (p < 0.05) than the others (0.293 vs. 0.420, 0.387, 0.390 and 0.407 with CPE vs. NE, CE, PE and NE-SBM, respectively). The apparent EE digestibility increased (p = 0.053) with the inclusion of extruded ingredients, (0.799, 0.749 and 0.794 vs. 0.719 and 0.702 with CE, PE and CPE vs. NE and NE-SBM, respectively). Daily allantoin excretion was lower (p < 0.01) in calves receiving the CPE diet than in those receiving the NE, PE and NE-SBM diets. Treatments did not affect the average daily gains (1.61 ± 0.022 kg d^− 1), however calves on the CPE diet showed a lower (p < 0.01) concentrate and total conversion ratios than those fed NE, PE and NE-SBM (2.60 vs. 2.79, 2.85 and 2.98 kg concentrate DM kg^− 1 daily gain and 2.93 vs. 3.09, 3.13 and 3.26 kg total DM kg^− 1 daily gain, respectively). The CE diet resulted in numerically higher (p > 0.05) concentrate and total DM conversion ratios (2.72 and 3.02) than CPE and lower (p < 0.05) than NE-SBM. Improvement in feed conversion ratio after extrusion would be related to a better starch utilisation and not to changes in microbial or dietary protein flow to the duodenum, although a better utilisation of fat energy cannot be disregarded.