Breeding Australian Illawarra Shorthorn cattle for resistance to Boophilus microplus. I. Factors affecting resistance

1978 ◽  
Vol 29 (2) ◽  
pp. 411 ◽  
Author(s):  
KBW Utech ◽  
GW Seifert ◽  
RH Wharton

Selection and breeding for tick resistance in an Australian Illawarra Shorthorn (AIS) herd was undertaken from 1966 to 1971. Mating of half the AIS herd with a Brahman bull in 1968–69 provided a comparison of tick resistance in selected Bos taurus and crossbred B. taurus x B. indicus cattle. Parent cows and their progeny were ranked for resistance to ticks, infestations of which were acquired as a result of grazing infested pastures, and from periodical artificial infestation with cohorts of c. 20,000 larvae of Boophilus microplus. Ranking and assessment of resistance levels were based on counts of semi-engorged female ticks on the right side. Parent cows selected for high resistance consistently carried fewer ticks than cows selected for low resistance. Mating of cattle selected for high resistance produced progeny that were significantly more resistant than the progeny of cattle selected for low resistance. However, the Brahman bull, which had slightly lower resistance than the AIS bull, produced progeny with higher resistance, even when mated with AIS COWS selected for low resistance. Pregnant cows were significantly less resistant than non-pregnant cows, and lactating cows were very much less resistant than non-lactating cows. Young cows were more resistant than older cows. Calves at foot carried fewer ticks than their dams when grazing infested pastures, but after weaning they were less resistant than their parents when resistance was determined from artificial infestations. Female calves carried fewer ticks than males on almost all occasions, but differences were not significant in winter. Significant seasonal changes in resistance were demonstrated in AIS and Brahman x AIS weaner and yearling cattle. All cattle were less resistant in winter. Changes were greatest in Brahman x AN females, on which the average numbers of female ticks that matured following artificial infestations in January 1970 (summer), July 1970 (winter) and January 1971 (summer) were 151, 1046 and 95 respectively.

1981 ◽  
Vol 34 (1) ◽  
pp. 27 ◽  
Author(s):  
AV Schleger ◽  
DT Lincoln ◽  
AS Bourne

Bos taurus cattle with high resistance to the tick Boophilus micro plus, whether free-grazing or in covered pens, had significantly more arteriovenous anastomoses (A VA) in their skin than did animals of low resistance. These differences in number of A VA associated with resistance level were most marked above the level of the sebaceous gland in the neck region, an area favoured for tick feeding. In this skin layer, the number of AVA in low-resistance animals (4�0�0�4 per 2�1 mm) was significantly lower than in animals of high resistance (12�3 � 2�2 per 2�1 mm) while the mean value for the naive animals (8�2 � 1 �9 per 2�1 mm) was intermediate. No differences in morphology of AVA were detectable between the three groups using light microscopy.


1970 ◽  
Vol 21 (1) ◽  
pp. 163 ◽  
Author(s):  
RH Wharton ◽  
KBW Utech ◽  
HG Turner

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.


1970 ◽  
Vol 21 (1) ◽  
pp. 181
Author(s):  
HG Turner

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.


Parasitology ◽  
1978 ◽  
Vol 76 (3) ◽  
pp. 379-386 ◽  
Author(s):  
D. Koudstaal ◽  
D. H. Kemp ◽  
J. D. Kerr

SummaryLarvae of Boophilus microplus were labelled with [32P] and used to study the rejection of larvae from British breed cattle with different levels of resistance. On animals of high resistance the loss of larvae due to grooming ranged from 9–54% during the first 24 h of infestation, and more time was spent grooming by these animals. Most of the grooming activity could be attributed to the presence of tick larvae and the presence of older tick stages did not increase the percentage of larvae lost. Grooming was directed to attached larvae and these could be removed. Animals of low resistance did not lose a significant number of larvae as a result of grooming, but all previously infested hosts lost a proportion of the larvae (18–39%) which could not be accounted for by grooming. This loss was greater than the total loss of larvae (11%) on animals not previously exposed to B. microplus.


1969 ◽  
Vol 20 (4) ◽  
pp. 783 ◽  
Author(s):  
RH Wharton ◽  
KLS Harley ◽  
PR Wilkinson ◽  
KB Utech ◽  
BM Kelley

Control of Boophilus microplus by pasture spelling, planned dipping, and simulated "conventional" control methods was compared in duplicate herds of British cattle, and by simulated "conventional" control methods in duplicate herds of Zebu x British and a single mixed herd of Zebu x British and British cattle. Herds under conventional control were treated with an acaricide (dipped) when the count of "standard" ticks (5 mm or more in length) on the right side averaged 20 or more per animal. Herds under pasture spelling grazed alternately in two adjacent paddocks; the summer spelling period was 3½ months, followed by spelling periods of 4½ months, and cattle were dipped on transfer between paddocks. Herds under planned dipping were dipped at 21-day intervals until few larvae remained on the pasture, this treatment being repeated when the count of standard ticks averaged more than 20 per animal. Observations over 2 years confirmed the results of an earlier experiment which showed that pasture spelling and planned dipping resulted in increased efficiency of tick control. Compared with British herds under conventional control which required dipping on 19 and 20 occasions, herds managed by pasture spelling were dipped only on seven occasions and showed a mean reduction of 81% in tick burden. Herds subjected to planned dipping required 18 treatments but the tick burden was reduced by 83%. The two Zebu x British herds required dipping on four and 10 occasions and showed a mean reduction in tick burden of 39% compared with British herds under conventional control. There was little improvement in tick control in the mixed herd of Zebu x British and British cattle. Assessment of the tick resistance status of the Zebu x British cattle by artificial infestation with known numbers of larvae showed that the survival to mature female ticks was 1.3 and 1.8% for the herds requiring four and 10 acaricidal treatments respectively in the wet tropics. In a similar assessment of the "resistant" Australian lllawarra Shorthorn (AIS) cattle herds which required one treatment or none over a tick season in southern Queensland (Wilkinson 1962) the survival was 4.4 and 5.2% respectively. The mean survival of female ticks to maturity on individual Zebu x British cattle was 1.4% (range 0.01–6.6%) compared with 8.1 % (0.2–27.4%%) for AIS cattle.


2021 ◽  
Vol 8 ◽  
Author(s):  
Phasamon Saisawart ◽  
Somchin Sutthigran ◽  
Kumpanart Soontornvipart ◽  
Chutimon Thanaboonnipat ◽  
Damri Darawiroj ◽  
...  

Diaphragmatic excursion (DE) has been utilized for detecting respiratory related problems in humans. However, several factors should be considered such as the ultrasound technique and factors intrinsic to patients. Nevertheless, knowledge of the effect of these factors on DE in dogs is still lacking. The aim of this study was to evaluate the proper ultrasound technique by varying postures and diaphragmatic locations for DE measurement and to explore intrinsic factors such as diaphragmatic sides, sex, and body weight of dogs on DE. The prospective, analytic, cross-sectional study included 44 healthy dogs; 12 beagles and 32 dogs of other breeds. The experiment was divided into (i) an exploration of the proper ultrasound technique by varying postures (supine, standing, and recumbent in each of the right and left lateral positions), diaphragmatic locations (middle crus and proximal to the last rib), and diaphragmatic sublocations (xiphoid, mid, and proximal rib) for detection of DE and (ii) the evaluation of canine intrinsic factors affecting DE. The results show that the mid-diaphragmatic sublocation in the middle crus area in almost all positions revealed the highest percentage DE detection. However, DEs were revealed to be more accessible in the supine position. There was no significant difference in DE between the right and the left diaphragms or between the sexes of beagle dogs. However, body weight was significantly correlated with the DE among dogs of various sizes. In conclusion, the posture of the dogs and the diaphragmatic location can affect DE evaluation. Neither sex nor diaphragmatic side had an influence, but body weight was revealed as a major factor in DE in dogs.


2020 ◽  
Vol 19 (2) ◽  
Author(s):  
Rio Saputra ◽  
Mokhammad Najih

<p><em>Suspects have the right to obtain legal assistance, especially for suspects who are classified as economically disadvantaged in accordance with Article 56 of the Criminal Procedure Code (KUHAP). The facts show that there are many irregularities in the implementation of legal aid, therefore it is necessary to know about the implementation of free legal aid for suspects who are incapacitated at the level of investigation and the factors that become obstacles in the implementation of legal aid. This legal research is an empirical legal research and this research is descriptive in nature. The data used are primary data and secondary data. The techniques used to collect data were document study techniques and interview techniques. Inhibiting factors affecting the implementation of free legal aid for suspects who are unable at the level of investigation can be classified and differentiated into 3 factors, namely, legal substance, legal structure, and legal culture).</em></p><p><strong><em>Keywords: </em></strong><em>Legal Aid, Criminal Cases</em></p>


Author(s):  
L. Yarmots ◽  
G. Yarmots ◽  
A. Belenkaya

For ruminants, especially high-yielding animals in addition to the complete supply of animals with protein, its digestibility in the rumen is important. With low protein digestibility in the rumen, the released ammonia will be more effectively used by the rumen microflora, and the undigestible protein in the subsequent sections of the digestive tract can serve as a source of amino acids for the body. The use of concentrate mixtures with the inclusion of local, affordable and cheaper grain feeds, in particular a high-energy and protein ingredient- rapeseed presscake makes it possible to increase the milk productivity of cows throughout lactation. These presscakes are well balanced in their amino acid composition and belong to feeds whose protein has a low degree of digestibility in the rumen. The purpose of the researches was to study the digestibility of nutrients and milk productivity of cows when using the concentrate mixture with the inclusion of rapeseed presscake. In the scientific and economic experiment has been carried out on lactating cows, where the cows of the experimental group in the concentrate mixture of peas has been replaced with rapeseed presscake the digestibility of nutrients in the ration, energy metabolism and milk productivity have been studied. Studies have shown that almost all the nutrients were significantly better digested by the animals of the experimental group. Energy in milk was more allocated by cows of the experimental group by 6,29 MJ. From cows of the experimental group for 100 and 305 days of lactation has been obtained more milk by 6,27 and 7,06 %, respectively, than from control herdmates. The biochemical parameters of blood were within the limits of the physiological norm in animals of both groups. Thus, the replacement of peas with rapeseed presscake in the concentrate mixture did not have a negative influence on the metabolic processes and helped to increase the milk productivity of cows.


Author(s):  
Monika Lewandowska ◽  
Rafał Milner ◽  
Małgorzata Ganc ◽  
Elżbieta Włodarczyk ◽  
Joanna Dołżycka ◽  
...  

AbstractThere are discrepancies in the literature regarding the course of central auditory processes (CAP) maturation in typically developing children and adolescents. The purpose of the study was to provide an overview of age – related improvement in CAP in Polish primary and secondary school students aged 7–16 years. 180 children/adolescents, subdivided into 9 age categories, and 20 adults (aged 18–24 years) performed the Dichotic Digit Test (DDT), Duration Pattern Test (DPT), Frequency Pattern Test (FPT), Gap Detection Test (GDT) and adaptive Speech-in-Noise (aSpN). The 12-year-olds was retested after w week. We found the age effects only for the DDT, DPT and FPT. In the right ear DDT the 7-year-olds performed more poorly than all groups ≥12. In the left ear DDT both 7- and 8-year-olds achieved less correct responses compared with the 13-, 14-, 15-year-olds and with the adults. The right ear advantage was greater in the 7-year-olds than in the 15-year-olds and adult group. At the age of 7 there was lower DPT and FPT scores than in all participants ≥13 whereas the 8-year-olds obtained less correct responses in the FPT than all age categories ≥12. Almost all groups (except for the 7-year-olds) performed better in the DPT than FPT. The test-retest reliability for all tests was satisfactory. The study demonstrated that different CAP have their own patterns of improvement with age and some of them are specific for the Polish population. The psychoacoustic battery may be useful in screening for CAP disorders in Poland.


Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2130
Author(s):  
Ken’ichi Matsumoto ◽  
Yui Nakamine ◽  
Sunyong Eom ◽  
Hideki Kato

The transportation sector is a major contributor to carbon dioxide emissions, and the resulting climate change. The diffusion of alternative fuel vehicles, including hybrid electric vehicles (HEV), is an important solution for these issues. This study aimed to evaluate the factors affecting the ownership ratio of HEVs, particularly passenger vehicles, and the regional differences in the purchase of HEVs in Japan. This study performed a fixed-effects regression analysis with panel data for 47 prefectures during the period 2005–2015 to evaluate the factors affecting the HEV ownership ratio and conducted three cluster analyses to investigate the regional differences in diffusion in terms of price categories, body types, and drive systems of HEVs. Some demographic and social factors were found to affect the ownership ratio in Japan, whereas economic factors, including prefecture-level subsidies for purchasing HEVs, were not. Regarding regional differences, prefectures in urban areas with higher income levels tend to purchase more expensive and large-sized HEVs. These results suggest that a strategy to sell the right vehicle to the right person and region is essential for further promoting HEVs in Japan.


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