Bos indicus and Bos taurus crossbred dairy cattle in Australia. III.* A climate room test of heat tolerance used in the selection of young sires for progeny testing

1974 ◽  
Vol 25 (6) ◽  
pp. 1023 ◽  
Author(s):  
TE Allen ◽  
SM Donegan
Keyword(s):  
Heat Tolerance ◽  
Rectal Temperature ◽  
Large Scale ◽  
Bos Indicus ◽  
Rank Correlation ◽  
Tolerance Test ◽  
Breeding Program ◽  
Progeny Testing ◽  
Stressful Environment ◽  
Rate Score

A heat tolerance test for cattle is described, and the results of its use over a 7 year period in a largescale breeding program are given. Animals were subjected to the test on up to three occasions, each test comprising 1 week in an anteroom at moderate temperature followed by 5 days in a climate room at high temperature. Measurements of sweating and respiratory rates, rectal temperature and feed and water consumption are given. The animals were ranked by means of a total score which was made up of the' sum of a sweating rate score and feed intake score less the sum of a rectal temperature score and respiratory rate score. A significant Spearman's rank correlation coefficient of 0.67 was obtained between the ranking of 44 heifers in two separate series of tests. Comparison of bulls from dams selected and unselected for milk production in a stressful climate showed the bulls from the selected dams to be superior in heat tolerance. In the large-scale breeding program, the test selected bulls with three-eighths or half Bos indicus blood in preference to those with quarter Bos indicus blood; and within the quarter-breds it selected those out of dams bred in herds located in a stressful environment in preference to similar crossbred bulls out of dams bred in a temperate environment.

An experimental study of heat tolerance of cattle

1956 ◽  
Vol 7 (5) ◽  
pp. 469 ◽  
Author(s):  
DF Dowling
Keyword(s):  
Experimental Study ◽  
Heat Stress ◽  
Heat Tolerance ◽  
Rectal Temperature ◽  
Tolerance Test ◽  
The Body ◽  
Normal Body Temperature ◽  
Factors Influencing ◽  
Major Factors ◽  
Temperature Responses

The ability of cattle to maintain a normal body temperature in a dry, hot, inland Australian environment is associated with their ability to dissipate excess heat from the body. A heat tolerance test, based on rectal temperature responses after exercise, is reported. This test indicates the animal's capacity to lose heat. Forty animals, classified on their coat covering, were included in the experiments described. The differences in coat covering are described and associated with differences in rectal temperature under various forms of heat stress. The results serve to illustrate the basic weaknesses of any field test (or hot-room test) which cannot be carried out under conditions where major factors influencing the "adaptability" and type of coat can be kept uniform for all animals tested.

Bos indicus and Bos taurus crossbred dairy cattle in Australia. IV.* Progeny testing and expected rate of genetic improvement

1976 ◽  
Vol 27 (2) ◽  
pp. 309 ◽  
Author(s):  
IR Franklin ◽  
RH Hayman ◽  
RO Hewetson
Keyword(s):  
Dairy Cattle ◽  
Heat Tolerance ◽  
Genetic Improvement ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Progeny Testing ◽  
Dairy Farmers ◽  
Improvement Program ◽  
Tropical Environments ◽  
Tick Resistance

A dairy improvement program designed to develop a breed of cattle adapted to tropical environments is described. Each year young crossbred (Bos indicus x Bos taurus) bulls are screened for heat tolerance and tick resistance, and then progeny-tested in the herds of cooperating dairy farmers. Estimates of phenotypic and genetic means, variances and correlations are presented for production of milk and milk components, and the rate of genetic improvement is discussed. In particular the heritability of milk yield in the crossbred progeny is 0.27, and the theoretical rate of improvement is 2.6% per year. ____________________ *Part III, Aust. J. Agric. Res., 25: 1023 (1974).

scholarly journals Comparison of Rectal Temperature Responses During a Modified Heat Tolerance Test

2018 ◽  
Vol 50 (5S) ◽  
pp. 121
Author(s):  
Yuri Hosokawa ◽  
Kelsey M. Rynkiewicz ◽  
Luke N. Belval ◽  
Courteney L. Benjamin ◽  
Ryan M. Curtis ◽  
...  
Keyword(s):  
Heat Tolerance ◽  
Rectal Temperature ◽  
Tolerance Test ◽  
Temperature Responses

Repeatability of an Experimental Heat Tolerance Test and the Influence of Season

1953 ◽  
Vol 12 (4) ◽  
pp. 757-764 ◽  
Author(s):  
R. E. McDowell ◽  
C. A. Matthews ◽  
Douglas H. K. Lee ◽  
M. H. Fohrman
Keyword(s):  
Heat Tolerance ◽  
Tolerance Test ◽  
Experimental Heat

scholarly journals Genomic Selection for Any Dairy Breeding Program via Optimized Investment in Phenotyping and Genotyping

2021 ◽  
Vol 12 ◽  
Author(s):  
Jana Obšteter ◽  
Janez Jenko ◽  
Gregor Gorjanc
Keyword(s):  
Genomic Selection ◽  
Genetic Gain ◽  
Breeding Program ◽  
Progeny Testing ◽  
Initial Training ◽  
Training Population ◽  
Breeding Programs ◽  
Use Of Resources ◽  
Dairy Cattle Breeding ◽  
Close Relatives

This paper evaluates the potential of maximizing genetic gain in dairy cattle breeding by optimizing investment into phenotyping and genotyping. Conventional breeding focuses on phenotyping selection candidates or their close relatives to maximize selection accuracy for breeders and quality assurance for producers. Genomic selection decoupled phenotyping and selection and through this increased genetic gain per year compared to the conventional selection. Although genomic selection is established in well-resourced breeding programs, small populations and developing countries still struggle with the implementation. The main issues include the lack of training animals and lack of financial resources. To address this, we simulated a case-study of a small dairy population with a number of scenarios with equal available resources yet varied use of resources for phenotyping and genotyping. The conventional progeny testing scenario collected 11 phenotypic records per lactation. In genomic selection scenarios, we reduced phenotyping to between 10 and 1 phenotypic records per lactation and invested the saved resources into genotyping. We tested these scenarios at different relative prices of phenotyping to genotyping and with or without an initial training population for genomic selection. Reallocating a part of phenotyping resources for repeated milk records to genotyping increased genetic gain compared to the conventional selection scenario regardless of the amount and relative cost of phenotyping, and the availability of an initial training population. Genetic gain increased by increasing genotyping, despite reduced phenotyping. High-genotyping scenarios even saved resources. Genomic selection scenarios expectedly increased accuracy for young non-phenotyped candidate males and females, but also proven females. This study shows that breeding programs should optimize investment into phenotyping and genotyping to maximize return on investment. Our results suggest that any dairy breeding program using conventional progeny testing with repeated milk records can implement genomic selection without increasing the level of investment.

scholarly journals Estimating an Aggregate Economic Genotype to Facilitate Breeding and Selection of Strawberry Genotypes in Southeast Queensland

2014 ◽  
Vol 139 (3) ◽  
pp. 253-260
Author(s):  
Mark E. Herrington ◽  
Craig Hardner ◽  
Malcolm Wegener ◽  
Louella Woolcock ◽  
Mark J. Dieters
Keyword(s):  
Rank Correlation ◽  
Breeding Population ◽  
Breeding Program ◽  
Production Costs ◽  
Breeding Value ◽  
Linear Quadratic ◽  
Gross Margin ◽  
Economic Weight ◽  
Non Linear ◽  
Gross Margins

The Queensland strawberry (Fragaria ×ananassa) breeding program in subtropical Australia aims to improve sustainable profitability for the producer. Selection must account for the relative economic importance of each trait and the genetic architecture underlying these traits in the breeding population. Our study used estimates of the influence of a trait on production costs and profitability to develop a profitability index (PI) and an economic weight (i.e., change in PI for a unit change in level of trait) for each trait. The economic weights were then combined with the breeding values for 12 plant and fruit traits on over 3000 genotypes that were represented in either the current breeding population or as progenitors in the pedigree of these individuals. The resulting linear combination (i.e., sum of economic weight × breeding value for all 12 traits) estimated the overall economic worth of each genotype as H, the aggregate economic genotype. H values were validated by comparisons among commercial cultivars and were also compared with the estimated gross margins. When the H value of ‘Festival’ was set as zero, the H values of genotypes in the pedigree ranged from –0.36 to +0.28. H was highly correlated (R2 = 0.77) with the year of selection (1945–98). The gross margins were highly linearly related (R2 > 0.98) to H values when the genotype was planted on less than 50% of available area, but the relationship was non-linear [quadratic with a maximum (R2 > 0.96)] when the planted area exceeded 50%. Additionally, with H values above zero, the variation in gross margin increased with increasing H values as the percentage of area planted to a genotype increased. High correlations among some traits allowed the omission of any one of three of the 12 traits with little or no effect on ranking (Spearman’s rank correlation 0.98 or greater). Thus, these traits may be dropped from the aggregate economic genotype, leading to either cost reductions in the breeding program or increased selection intensities for the same resources. H was efficient in identifying economically superior genotypes for breeding and deployment, but because of the non-linear relationship with gross margin, calculation of a gross margin for genotypes with high H is also necessary when cultivars are deployed across more than 50% of the available area.

scholarly journals 243 PREGNANCY RATES IN THE FIELD AFTER THE TRANSFER OF BOVINE IVP EMBRYOS VITRIFIED BY THE CRYOLOGIC VITRIFICATION METHOD

2005 ◽  
Vol 17 (2) ◽  
pp. 272 ◽  
Author(s):  
R. Fry ◽  
C. Earl ◽  
K. Fry ◽  
W. Lindemans
Keyword(s):  
Large Scale ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Pregnancy Rates ◽  
Chi Square ◽  
Full Field ◽  
Transfer Programs ◽  
Short Period ◽  
Rectal Palpation ◽  
User Friendly

Although large numbers of IVP embryos can be produced from donor cattle in a short period of time, commercial acceptance of the technology depends on the ability to cryopreserve these embryos and achieve a 50% pregnancy rate in large-scale embryo transfer programs. Many studies have reported low pregnancy rates of about 20% after the transfer of cryopreserved IVP embryos. We have developed the user friendly CryoLogic Vitrification Method (CVM) that vitrifies embryos on a solid surface at −196°C and warms them rapidly in a one-step procedure prior to transfer (Lindemans et al. 2004 Reprod. Fertil. Dev. 16, 174). We present an overview of the pregnancy rates in the field after vitrification of bovine IVP embryos by the CVM. The bos taurus IVP embryos in southern Australia (bT) and the bos indicus-based IVP embryos in northern Australia (bI) were produced by our standard TVR and IVP methodology (Fry et al., 2003 Theriogenology 59, 446). Pregnancy was determined by rectal palpation between Day 40 and Day 90 and differences between treatments were analyzed by chi-square. The development of the CVM has enabled the successful cryopreservation of bovine IVP embryos. In the laboratory the typical survival (90% re-expansion) and development (80% hatching) of IVP embryos post-vitrification is high and, as demonstrated here, the pregnancy rates after transfer are approaching commercially acceptable levels. However, further research is required to identify factors that may influence success under full field conditions, for both the IVP and the vitrification technologies. Table 1. Pregnancy rates for fresh IVP, CVM-vitrified IVP, and traditionally flushed embryos cryopreserved in glycerol

scholarly journals Reproductive and cost assessment of a seasonal breeding program with Bos indicus in tropical Mexico

2021 ◽  
Vol 26 (2) ◽  
pp. e2130
Author(s):  
José Francisco Martínez-Albarrán ◽  
Carlos Salvador Galina-Hidalgo ◽  
Ivette Rubio-Gutiérrez ◽  
Wendy Leticia Balam-Villarreal ◽  
Manuel D. Corro-Morales
Keyword(s):  
Pregnancy Rate ◽  
Breeding Season ◽  
Phase 1 ◽  
Bos Indicus ◽  
Fixed Time ◽  
Breeding Program ◽  
Tropical Region ◽  
Two Phases ◽  
One Year ◽  
The Cost

Objective. To compare the reproductive performance of postpartum and open Bos indicus cows and to study the cost effectiveness of retaining non-pregnant animals after a short breeding season in tropical region of Mexico. Material and Methods. A total of 128 Bos indicus were included, 87 postpartum cows (PP) with ≤90 days after calving and 41 open cows (OC) with >90 days open. The study was divided into three phases: 1) Estrus synchronization followed by FTAI (day 0-10), 2) Estrus detection and AI (day 11-45) and 3) Natural mating (day 46-90). For the first phase, all animals were synchronized and AI at fixed time (day 10). Cows displaying overt signs of estrus (day 11-45) were AI. Open cows during the previous two phases were exposed to the bull. Results. Pregnancy in phase 1 was different (p<0.01) for PP and OC groups, 58.6% and 34.1%, respectively. Overall pregnancy percentage over the second service was 42.5% (p>0.05). No differences (p>0.05) were observed at phase 3, average 44.2%. By the end of the breeding season, the cost of OC, was 3 times more than PP cows. Conclusions. Pregnancy rate at first phase was higher in PP cows than OC cows. At the end of breeding season, a pregnancy rate of 80% was found. Incorporation of open cows from previous breeding season was more expensive than PP cows in all phases of the breeding program. Retaining an open cow for rebreeding one year or more could not be economically feasible.

Genetic variation of rectal temperature and its relationship to milk production in Holstein dairy cows

2009 ◽  
Vol 2009 ◽  
pp. 63-63
Author(s):  
S Khalajzade ◽  
N Emam Jomeh ◽  
A Salehi ◽  
A Moghimi Esfandabadi
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Production ◽  
Heat Tolerance ◽  
Rectal Temperature ◽  
Weather Factors ◽  
And Performance ◽  
Very High ◽  
Selection Of ◽  
Holstein Dairy Cows

Milk production is significantly decreased by thermal stress. The survival and performance of an animal during heat stress periods depend on several weather factors, especially temperature and humidity. Researchers reported dramatic decreases in milk production as temperature rose above 30 degree of centigrade. Very high environmental temperature is common during the summer months in Iran. Rectal temperature is as indicator of heat tolerance and has been the most frequently used physiological variable for estimating heat tolerance in cattle. Some dairy cows are more heat tolerant and productive when subjected to heat stress. Identification and selection of heat stress resistant cattle offers the potential to increase milk yield in tropical environment. The aim of the present study was to estimate genetic parameters of heat tolerance and its relationship to milk production in Holstein Dairy Cows in Iran.

scholarly journals Thermal tolerance patterns across latitude and elevation

2019 ◽  
Vol 374 (1778) ◽  
pp. 20190036 ◽  
Author(s):  
Jennifer Sunday ◽  
Joanne M. Bennett ◽  
Piero Calosi ◽  
Susana Clusella-Trullas ◽  
Sarah Gravel ◽  
...  
Keyword(s):  
Cold Tolerance ◽  
Heat Tolerance ◽  
Thermal Tolerance ◽  
Large Scale ◽  
Global Climate ◽  
Climate Extremes ◽  
Species Traits ◽  
Acclimation Temperature ◽  
Tolerance Limits ◽  
Thermal Limits

Linking variation in species' traits to large-scale environmental gradients can lend insight into the evolutionary processes that have shaped functional diversity and future responses to environmental change. Here, we ask how heat and cold tolerance vary as a function of latitude, elevation and climate extremes, using an extensive global dataset of ectotherm and endotherm thermal tolerance limits, while accounting for methodological variation in acclimation temperature, ramping rate and duration of exposure among studies. We show that previously reported relationships between thermal limits and latitude in ectotherms are robust to variation in methods. Heat tolerance of terrestrial ectotherms declined marginally towards higher latitudes and did not vary with elevation, whereas heat tolerance of freshwater and marine ectotherms declined more steeply with latitude. By contrast, cold tolerance limits declined steeply with latitude in marine, intertidal, freshwater and terrestrial ectotherms, and towards higher elevations on land. In all realms, both upper and lower thermal tolerance limits increased with extreme daily temperature, suggesting that different experienced climate extremes across realms explain the patterns, as predicted under the Climate Extremes Hypothesis . Statistically accounting for methodological variation in acclimation temperature, ramping rate and exposure duration improved model fits, and increased slopes with extreme ambient temperature. Our results suggest that fundamentally different patterns of thermal limits found among the earth's realms may be largely explained by differences in episodic thermal extremes among realms, updating global macrophysiological ‘rules’. This article is part of the theme issue ‘Physiological diversity, biodiversity patterns and global climate change: testing key hypotheses involving temperature and oxygen’.

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