A practical future-scenarios selection tool to breed for heat tolerance in Australian dairy cattle

2017 ◽  
Vol 57 (7) ◽  
pp. 1488 ◽  
Author(s):  
Thuy T. T. Nguyen ◽  
Ben J. Hayes ◽  
Jennie E. Pryce

Climate change will have an impact on dairy cow performance. When heat stressed, animals consume less feed, followed by a decline in milk yield. Previously, we have found that there is genetic variation in this decline. Selection for increased milk production, a major breeding objective, is expected to reduce heat tolerance (HT), as these traits are genetically unfavourably correlated. We aimed to develop a future-scenarios selection tool to assist farmers in making selection decisions, that combines the current national dairy selection index, known as the balanced performance index (BPI), with a proposed HT genomic estimated breeding value (GEBV). Heat-tolerance GEBV was estimated for 12 062 genotyped cows and 10 981 bulls, using an established genomic-prediction equation. Publicly available future daily average temperature and humidity data were used to estimate mean daily temperature–humidity index for each dairy herd. An economic estimate of an individual cow’s heat-tolerance breeding value (BV_HT) was calculated by multiplying head-tolerance GEBVs for milk, fat and protein by their respective economic values that are already used in the BPI. This was scaled for each region by multiplying BV_HT by the heat load, which is the temperature–humidity index units exceeding the threshold per year at a particular location. BV_HT were incorporated into the BPI as: BPI_HT = BPI + BV_HT; where BPI_HT is the ‘augmented BPI’ breeding value including HT. A web-based application was developed enabling farmers to predict the future heat load of a herd and take steps to aim at genetic improvement in future generations by selecting bulls and cows that rank high for the ‘augmented BPI’.

2007 ◽  
Vol 2007 ◽  
pp. 158-158
Author(s):  
Mohammad Hassan Jahandar ◽  
Mohhamad Moradi Shahre Babak ◽  
Mahdi Elahi Torshizi

In order to evaluate genetic improvement in a selected population, variation resulted from environment and genetics should be dissociated. Because of the positive genetic correlation between milk fat yield and milk and protein yield, selection for milk production has often resulted in an increase in fat and protein yields however response for fat percentage is negative. However positive genetic trends between 0.73 to 0.95 kg per annum for milk fat yield in Holstein cattle have been reported in some studies that milk fat yield had less importance in selection index, also negative values are reported. Based on previous research, genetic improvement of milk fat yield up to 1 percent due to selection is possible and from a theoretical view, an improvement of about 2 percent is reported. With attention to selection in the herd and using progeny tested semen from foreign countries that have suitable genetic potential, this study was accomplished in order to estimate genetic parameters for milk fat and investigate genetic and environmental trends during 1990 to 2001.


Data ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 103 ◽  
Author(s):  
Roman Mylostyvyi ◽  
Olexandr Chernenko

Global climate change is a challenge for dairy farming. In this regard, identifying reliable correlations between environmental parameters and animals’ physiological responses is a starting point for the mathematical modeling of their effects on the future welfare and milk production of cows. The aim of the study was to examine the relationship between environmental parameters and the milk production of cows in hot period. Archival data from the Ukrainian Hydrometeorological Center were used to study the state of insolation conditions (IC), wind direction (WD), wind strength (WS), air temperature (AT), and relative humidity (RH). The temperature–humidity index (THI) (Kibler, 1964) and temperature–humidity index in the hangar-type cowshed (THICHT) (Mylostyvyi et al., 2019) served as integral indicators of the state of the cowshed’s microclimate. The daily milk yield (DMY), yield of milk fat (MF) and milk protein (MP), and percentage of milk fat (PMF) and protein (PMP) were taken into account by the DairyComp 305 herd management system (VAS, USA). Statistical data processing was performed using the mathematical functions of Microsoft Excel (Microsoft Inc.) and Statistica 10 (StatSoft Inc.). There was a weak correlation between IC and DMY at r = −0.2, between RH and DMY at r = +0.4, and between RH and MF at r = +0.2. Between DMY, MF, MP, and WS made up r = –0.2 to 0.4. Between DMY, MF, MP, and AT made up r = −0.2 to 0.5 (p < 0.05). The effects of weather factors on animal productivity will be the subject of further research.


2010 ◽  
Vol 39 (3) ◽  
pp. 685-694 ◽  
Author(s):  
Wander de Souza ◽  
Orlando Rus Barbosa ◽  
Jair de Araújo Marques ◽  
Marco Aurélio Teixeira Costa ◽  
Eliane Gasparino ◽  
...  

The aim of this work was to verify if the presence of trees and its height in formed silvipastoral systems with eucalyptus planted in rank can modify the microclimate and improve the environment for bovine raising during the day in summer. It was evaluated the microclimate of the environment in formed silvipastoral systems in rank of eucalyptus with 8 m, 18 m and 28 meters of height, compared to a system no shade in the summer. The experimental design was a split plot with six hour time in sub parcels. The systems are made up of parcels and the months as block in four replications and the interaction hour × system. The air temperature, black globe temperature, relative humidity and wind speed were observed to create the following indexes for thermal comfort: temperature-humidity index; black globe-humidity index; heat load index and the radiant thermal load. Excepted for the relative humidity, there was interaction for time × system for all variables and indexes. Interaction occurred for: air temperature at 10 a.m. and 6 p.m.; wind speed from 8 a.m. to 4 p.m.; temperature humidity index at 10 a.m. and 12 p.m.; black globe temperature, black globe humidity index, heat load index, and radiant thermal load at all the hours. During the summer, the system with shade of 28 m trees had the lowest average of black globe temperature; wind speed; black globe humidity index; radiant thermal load index; and heat load index. There was a reduction of wind speed average in systems 8 m, 18 m and 28 m trees in, respectively, 20.7; 50.0 and 48.0% in relation to no shade system; however it was not proportional to the height, with influence of the rank porosity and pantries height. Nevertheless, for radiant thermal load index the reduction was proportional to the height of the trees with 10.24; 12.49 and 20.76%, respectively, for 8 m, 18 m and 28 meters of height. There was a reduction of the thermal stress in the environment due to the presence of trees, being the heat load index thermal the index that better demonstrated the effect, despite of not being proportional to the rank height.


2020 ◽  
Vol 60 (16) ◽  
pp. 1925
Author(s):  
A. M. Lees ◽  
M. L. Sullivan ◽  
J. C. W. Olm ◽  
A. J. Cawdell-Smith ◽  
J. B. Gaughan

Context Annually, millions of sheep are exported from Australia to the Middle East, typically during the southern hemisphere winter to the northern hemisphere summer. During these voyages, sheep can be exposed to relatively rapid changes in ambient conditions within a short period of time (≤29 days); therefore, excessive heat load concerns can arise. Aims The aim of this study was to define the responses of sheep to incremental heat load under simulated live export conditions. The study herein describes (1) the heat load imposed, and (2) the effect of this heat load on the growth, performance and behavioural responses of sheep during periods of incremental heat load. Methods A total of 144 Merino wethers (44.02 ± 0.32 kg) were included in a 29-day climate controlled study using two cohorts of 72 sheep (n = 2), exposed to two treatments: (1) thermoneutral and (2) hot (HOT). Ambient temperature (°C) and relative humidity (%) for the HOT treatment were modelled from live export voyages from Australia to the Middle East in July. Climatic conditions within the climate control chambers were recorded at 10-min intervals, then used to calculate a temperature humidity index. Sheep posture, rumination, eating, drinking and demeanour (calm, agitated or depressed) were observed four times daily at 3-h intervals between 0800 hours and 1700 hours. Feed intake was recorded daily and water intake was measured using an automated meter. Sheep were weighed on Day 0 and then at 7-day intervals. Sheep were weighed at slaughter and carcass weights were obtained, these data were used to determine carcass dressing percentage. Data were analysed using a repeated measures model, with a compound symmetry covariance structure. Key results Climatic conditions in the HOT treatment increased incrementally between Day 1 (temperature humidity index ≥19) and Day 29 (temperature humidity index ≤34.7). Behaviour, feed intake, average daily gain (g/day), carcass weight (kg) and dressing percentage were not influenced by treatment (P &gt; 0.05). Sheep in the HOT treatment group showed a 137% increase in water intake (P &lt; 0.01) and on average consumed 2.15 L/sheep.day, whereas the thermoneutral group consumed 1.67 L/sheep.day. Conclusions These results suggest that these sheep were capable of maintaining feed intake and growth despite exposure to heat load, albeit with a 137% increase in water intake. Implications These results highlight the resilience of the Australian Merino genotype, as these sheep were capable of maintaining feed intake and growth during exposure to heat load. As the climatic conditions in this study were modelled based on typical live export vessel conditions, these results may suggest that the climatic conditions experienced by sheep during voyages may not be as critical as previously thought.


2019 ◽  
Vol 57 ◽  
pp. 126-135
Author(s):  
А. M. Salohub

The research was carried out to study the influence of genotypic and paratypical factors on the traits of milk production of cows Ukrainian Red-and-White dairy breed LLC "Mena-Avangard" Chernihiv region. In the conditions of pedigree herd, studied four groups of crossbred animals with conditional share heredity of Holstein breed: I – < 62.5%; ІІ – 62.6–75.0; III – 75.0–87.5 and IV – 87.6 and > . According to results of researches cow’s crossbred groups of breeding herd Ukrainian Red-and-White breed with a different conditional blood by Holstein breed, was found reliable influence of heredity of improving breed on the level of milk yield and output of milk fat in the dynamics of estimated lactation. Cow’s milk yield with each heredity increase of improver breed grew respectively by 12.5% within crossbred groups. Thus, when comparing cow's group of Holstein blood < 62.5% with their counterparts with blood 62.6–75.0%, advantage was 301 kg in favor of the latter with reliable difference at P < 0.01. Next blood increase to 75.0–87.5% led to a corresponding increase in yield at 262 kg (P < 0.01). Animals with heredity Holstein breed 87.6% higher than the previous generation dominated with a high difference 345 kg of milk (P < 0.001). The blood flow of Holstein breed by 25% resulted in increased milk yield of first-calf cows by 908 kg (P < 0.001). The fat content in milk through this crossing the blood decreased only 0.05% and was not confirmed by reliability, whereas milk fat yield increased with a high significance difference of 31.9 kg (P < 0.001). According to results of one-factor dispersion analysis, was found that value of yield and output level of milk fat in the first lactation cows of Ukrainian Red-and-White dairy breed, respectively, by 5.5–6.2 and 4.7–9.2%, depend on paratypical factors (year and season of birth and year and season of the first calving), as confirmed by high reliability according to Fisher's criterion. The level of milk yield and milk fat cows in first lactation significantly - correspondingly 25.3 and 15.8%, depending on the conditional share of heredity Holstein breed. However, the highest rates of influence on yield level and milk fat of the first-calf cows were obtained by size of comprehensive selection index of cow's mother (57.1 and 44.7%), average breeding value of mother for milk yield (64.4 and 45.4%), and for milk fat (53.5 and 38.9%). With high reliability on indicators of milk production influencing standardized breeding value parent by quantity of milk yield and milk fat (= 0.283 and 0.178). Calculations show that dispersion of traits development of yield and milk fat of cows first-calf due to the influence of heredity of sires used lines and is respectively 15.7 and 10.9%. Fisher's criterion reliability by these indicators exceed the threshold of the third level (P < 0.001). Thus, the power of influence heredity of Holstein breed, selection indexes of mothers and parents of cows and father lines on the milk yield level and milk yield output indicating the possibility of effective breeding of the studied dairy cattle by selection of ancestors with a high estimation of selection indices and pedigree value.


2019 ◽  
Vol 6 (1) ◽  
pp. 70
Author(s):  
Elmy Mariana ◽  
Cece Sumantri ◽  
Dewi Apri Astuti ◽  
Anneke Anggraeni ◽  
Asep Gunawan

ABSTRAKTujuan penelitian ini adalah untuk mengetahui pengaruh ketinggian tempat terhadap kondisi mikroklimat,termoregulasi dan produktivitas sapi Friesian-Holstein (FH). Penelitian dilakukan pada tiga lokasi dengan ketinggian berbeda, yaituPodok Ranggon (97mdpl), Ciawi (576mdpl), dan Lembang (1241mdpl). Sebanyak 63 sapi FH dalam kondisi laktasi normal digunakan dalam penelitian ini.  Aspek lingkungan meliputi suhu udara, kelembaban relatif dan Temperature-Humidity Index di dicatat setiap 2 jam dari pukul 08.00 sampai 16.00 WIB. Parameter termoregulasi yang diamati terdiri atas suhu kulit (Ts),suhu rektal (Tr), suhu tubuh (Tb), denyut jantung (Hr),laju pernapasan (Rr), dan Heat Tolerance Coeficient (HTC).Berdasarkan nilai Ta, Rr dan THI, dataran rendah memberikan dampak cekaman panas sedang, dataran sedangdan tinggi memberikan dampak cekaman panas ringan pada sapi perah. Hasil menunjukkan bahwa sapi dataran rendah memiliki Nilai HTC, Tr, Ts dan Tb tertinggi (P<0,05) dan Hr yang terendah (P<0,05). Produksi susu di ketiga lokasi penelitian berbeda nyata (P<0,05), dengan produksi susu tertinggi di dataran tinggi (13,1±3,52 kg),dataran sedang (11,3±4,73 kg) dan dataran rendah (7,0±3,36 kg). Secara umum sapi FH di dataran rendah, sedang dan tinggi tercekam panas akibat kondisi lingkungan yang berada pada kondisi di luar zona nyamanselama musim kemarau, akan tetapi mampu beradaptasi terhadap kondisi tersebut. Kata kunci: ketinggian tempat, produktivitas, sapi perah, cekaman panas, termoregulasiABSTRACTThe purpose of this research was to determine altitude effect on microclimate, thermoregulation and productivity of Friesian Holstein. Research was conducted in different altitudes, i.e.: Pondok Ranggon (97m asl), Ciawi (576m asl), and Lembang (1241 m asl). A total of 63 FH cows in normal lactation were used in this study. Microclimate aspects observation includes environmental temperature (Ta), relative humidity (RH) and Temperature-Humidity Index (THI) were recorded every 2 hours from 08.00 to 16.00. The physiological responses measurements consisted of skin temperature (Ts), rectal temperature (Tr), body temperature (Tb), heart rate (Hr), respiratory rate (Rr) and Heat Tolerance Coeficient (HTC). Lowland environmental provide moderate heat stress, while the medium and highland impacts with mild stress. The results showed that lowland cows have highest HTC, Tr, Ts and Tb (P<0.05) and lowest Hr (P<0.05). Milk production in the different altitude was significantly different (P<0.05), with the highest milk yields in the highlands (13.1±3.52 kg), medium (11.3±4.73 kg) and lowland (7.0±3.36 kg). In general, HF dairy cows in low-, medium- and highland are exposed to climatic stress during dry season conditions, although they have the ability to adapt physiologically and cope with environmental stress.  Keyworlds: altitude, dairy cattle, heat stress, productivity, physiological responses


2020 ◽  
Vol 20 (2) ◽  
Author(s):  
Yetmaneli Yetmaneli ◽  
B. P. Purwanto ◽  
Rudi Priyanto ◽  
Wasmen Manalu

ABSTRAK. Penelitian bertujuan melihat potensi iklim mikro dan respon fisiologis sapi Pesisir yang dipelihara di dataran rendah (Kota Padang (0-300 m dpl )) dan dataran tinggi (BPTU Padang Mengatas ( 600 m dpl)) Sumatera Barat. Materi yang digunakan dalam penelitian ini 8 ekor sapi Pesisir, variabel yang diukur terdiri dari 2 aspek yaitu lingkungan abiotik dan aspek fisiologis sapi Pesisir. Aspek lingkungan abiotik berupa suhu lingkungan (Ta), kelembapan udara (RH) serta Temperature Humidity Index (THI). Variabel fisiologis sapi meliputi suhu rektal (Tr), suhu kulit (Ts), frekuensi pernapasan (RR) dan denyut jantung (HR). Tr dan TS digunakan menghitung suhu tubuh sapi (Tb). Tr dan RR digunakan menghitung Heat Tolerance Coefficient (HTC). Uji beda (t-test) digunakan untuk mengetahui ada tidaknya perbedaan kondisi iklim dan respon fisiologis sapi Pesisir di dataran rendah dan tinggi Sumatera Barat. Hasil penelitian menunjukkan potensi iklim di dataran rendah adalah rerata suhu lingkungan 29,96°C, rerata kelembapan 64,22%, rerata THI 79,96 sedangkan potensi iklim di dataran tinggi adalah rerata suhu lingkungan 25,42°C, rerata kelembapan 69,48%, rerata THI 74,3. Rerata daya tahan panas sapi di dataran rendah 1,78 dan dataran tinggi 1,82. Kesimpulan penelitian menunjukkan potensi iklim dataran rendah untuk pemeliharaan sapi termasuk zona cekaman panas sedangkan dataran tinggi dalam cekaman ringan. Kondisi fisiologis sapi Pesisir di dataran rendah yang berbeda dengan sapi yang di dataran tinggi adalah suhu rektal, suhu kulit, suhu tubuh dan denyut jantung sedangkan frekuensi pernapasan didapatkan sama di kedua dataran. Daya tahan panas sapi Pesisir cukup baik ditemui di kedua dataran Sumatera Barat. (Microclimate and physiological responses of Pesisir cattle at lowland and highland of West Sumatra) ABSTRACT. This research aimed to investigate the potential of microclimate and physiological responses of Pesisir cattle that are maintained in lowland (Padang City (0-300 m asl)) and highland (Padang Mengatas BPTU ( 600 m asl)) in West Sumatra. The experimental animals were 8 pesisir cattle. The measured variables were abiotic environment and physiological responses of Pesisir cattle. Abiotic environmental measures were ambient temperature (Ta), humidity (RH) and Temperature Humidity Index (THI). Physiological variables were rectal temperature (Tr), skin temperature (Ts), respiratory rate (RR), and heart rate (HR). Tr and Ts were used to determine body temperature (Tb). Tr and RR are variables for calculating Heat Tolerance Coefficient (HTC). To determine whether there are differences in climatic conditions and physiological values in the two regions, the data were analyzed using a t-test. The results showed that climate potential in the lowlands was the average Ta 29.96° C, the average Rh 64.22% with an average THI 79.96 while the potential climate in the highlands was the average Ta 25.42°C, the average Rh 69, 48% with a mean THI of 74.3. The average HTC of cattle in the lowlands is 1.78 and the highlands is 1.82. The conclusion showed the climate potential of lowland for raising beef cattle includes heat stress zones, while the highlands there was mild stress. The physiological conditions of Pesisir cattle in the lowlands different from the highlands are Tr, Ts, Tb, and HR while RR is found the same in both plains. HTC of Pesisir cattle is good in both plains of West Sumatera.


2018 ◽  
Vol 63 (No. 10) ◽  
pp. 379-388 ◽  
Author(s):  
H. Luik-Lindsaar ◽  
A.H. Viira ◽  
H. Viinalass ◽  
T. Kaart ◽  
R. Värnik

The effects of genetic level and output quality characteristics on technical efficiency (TE) of dairy farms were studied. The average total relative breeding value (RBV) at herd level was considered a parameter of the genetic level and production potential of the main input (dairy cows), while somatic cell count (SCC) and milk composition characterise the quality of the main output (milk) of dairy farms. The analysis was carried out in two stages: data envelopment analysis was used in the first stage and fractional regression model in the second stage, combining the data collected by the Estonian Farm Accountancy Data Network with the data from the Estonian Livestock Performance Recording Ltd. The results showed that the TE of fully efficient dairy farms is positively affected by the total RBV (P &lt; 0.05), number of dairy cows in the herd (P &lt; 0.05), and negatively affected by the SCC (P &lt; 0.001) and costs of purchased feed per kg of produced milk (P &lt; 0.01). Among the inefficient farms, the TE was positively affected by the lifetime daily milk yield (P &lt; 0.05), and average milk fat (P &lt; 0.1) and protein (P &lt; 0.05) contents. The results confirm our hypothesis that the genetic level of dairy herd and milk quality have a positive effect on the TE of dairy farms.


Author(s):  
K.ZH. ZHUMANOV ◽  
◽  
T.N. KARYMSAKOV ◽  
M.A. KINEEV ◽  
M.V. TAMAROVSKIY ◽  
...  

According to the current “Instruction” used in dairy cattle selection and breeding in the Republic of Kazakhstan, bulls-producers of dairy breeds are assessed according to the their offspring quality based on the principle of “peer daughter”. This means that the phenotypic indicators of the daughters of the tested bulls are compared with the corresponding indicators of their peers. In European countries with developed dairy cattle breeding, as well as in Canada, the USA, etc., to ensure a reliable forecast of the genetic value of individuals (primarily, bulls-producers), use is made of the best linear unbiased forecast method (BLUP method). This method implies that the breeding value of producers is determined by the deviation values of the development of traits of the examined animal from its average values in the population. Especially urgent area is the research aimed at improving breeding programs, including assessing the breeding value of bulls-producers of dairy breeds using BLUP methods based on the productive qualities of the mass of dairy cattle in the Republic of Kazakhstan. The research material included the data on the phenotypic indicators of the milk productivity of first-calf cows (the amount of milk yield, the content of fat and protein in milk, the yield of milk fat and protein) of the Holstein black-motley dairy cattle breed, obtained from the information and analytical database of the Republic of Kazakhstan for 2016–2017. It was found that when evaluating according to the official “Instruction”, 16 sires out of 256 bulls (6.2%) got the stud category in 2016, 14 sires (9.2%) out of 152 bulls in 2017, and – 30 sires of 249 bulls (12.0%) over the cumulative period. The results of the conducted research prove that the use of the classic “Instructions” in dairy cattle breeding has lower efficiency (by 42.8–90.0%) as compared with the assessment of the breeding value of bulls based on the BLUP method.The selection of sire bulls into breeding groups based on the “peer daughter” methodology is not reliable enough and rather ineffective. Comparing the results of assessing the breeding qualities of sire bulls, obtianed using two methods in all compared periods (2016, 2017, 2016–2017), the authors established a clear superiority of the BLUP method over the current Instruction used in the Republic of Kazakhstan.


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