Study on Functional Traits of Arsi Cattle Reared in the East Shoa and West Arsi Zones of Oromia, Ethiopia

The study was conducted in the East Shoa and West Arsi Zones of Oromia Region with the objective to assess the functional traits of Arsi cattle in their native areas. Two hundred forty cattle keepers were identified using random sampling techniques. The study was conducted in five districts, namely Adami Tullu Jidokombolcha (ATJK), Bora, Dodola, Shala and Negele-Arsi. The survey revealed that the age at first mating, age at first calving, and calving interval of Arsi cattle at on-farm level were 43.5, 55.9 and 19.1 months, respectively. The lactation length and milk yield of Arsi cattle were 9.6 months and 1.66 liters per day, respectively. The working life of oxen was 7.7 years. The observed results on reproduction and production of Arsi cattle at on-farm level are good indicators of information for further evaluation of their performances.

​Genetic Polymorphism within Exon 3 of HSP90AA1 Gene and its Association Studies in Sahiwal and Crossbred Cows

Background: Heat shock proteins (HSPs) are molecular chaperones that play a critical role in recovering cells from stress and form a primary system for intra cellular self defense. They are highly conserved and play a crucial role in cellular thermo tolerance and heat stress response. Though there are many HSP genes, thermo tolerance is mainly correlated with HSP70 and HSP90 genes in Livestock species. Polymorphisms in these genes have shown an association with heat tolerance, milk production, fertility and disease susceptibility in livestock. They can be used as genetic markers for the selection of animals with better climate resilience, immune response and superior performance. Methods: The present study was carried out in Sahiwal (n=50) and Crossbred cows (n=50) with the objective to identify polymorphisms in HSP90AA1 gene. A 450 bp fragment of bovine HSP90AA1 gene covering exon3 was subjected to Polymerase Chain Reaction-Single-Strand Conformation Polymorphism (PCR-SSCP) technique to identify the polymorphism. PCR-SSCP patterns were correlated with the physiological, productive and reproductive traits in Sahiwal and crossbred cows using the univariate GLM model of SPSS 25. Result: The PCR-SSCP of exon 3 of HSP90AA1 gene yielded two conformational patterns AA and AB corresponding to two allelic variants A and B in both Sahiwal and crossbred cows. The allele frequencies of A and B were 0.78 and 0.22 and 0.84 and 0.16 in Sahiwal and crossbred cows, respectively. The association analysis of SSCP patterns revealed that genotype AA had higher lactation length in Sahiwal cows and higher total lactation milk yield and peak yield in crossbred cows.

Impact of Non-genetic Parameters Altering Milk Yield Performance in Zebu Cows

Background: Animal phenotype performance depends on both genetic and non-genetic factors, but mostly the genetic part analysed leaving non genetic parameters unnoticed. The aim of the study is to understand impact of non-genetic factors governing milk yield performance in Deoni cows. Methods: A total of 821 lactation records from 340 lactating cows (2002-2017) along with their age at first calving, parity, season of calving were collected. These data were standardized and analysed to find significant differences using Duncan’s multiple range Test. Result: Deoni cows showed significant increase (P less than 0.05) in both lactation milk yield and lactation length with increase in parity. Season of calving had significant affects (P less than 0.05) on lactation milk yield but not in lactation length. Increase in age at first calving revealed there was a significant difference (P less than 0.05) in both lactation milk yield and lactation length.

Effect of Temperature-Humidity-Index on Milk Performances of Local Born Holstein Dairy Cows Under Saharan Climate

The objective is to study the effect of heat stress on milk yield (MY) relative to milking records (n=18178) of native Holsteins (n=187), in the region of Ghardaia, according to periods of HS, using the temperature-humidity index (THI). With THI >72 during 07 months in the study area, which significantly (P<0.001) decrease the MY (-15.5% corresponding to 21.73 kg). Also, calving periods led to a significant drop (P < 0.001) in overall MY (7030.35 kg) of the order of (-14.6%), and over the lactation length (353.43 d), which explains 41% of the variations in MY. In addition, the non-significant effect (P=0.212) of the lactation range on the increase in MY, moreover, the lactation length shows a non-significant (P = 0.108) decrease (-4.68%) during heat stress (HS). Furthermore, the significant effect (P <0.001) of the interaction (Milking frequency × THI) on MY, when THI variates from < 74 to > 84, with regression of (-16.82% and -08.82%) of the MF (2X and 3X), respectively. Again, the NH cow is less sensitive to hyperthermia, so THI explains only 2% of the variation in MY levels. Thus, NH in arid regions have the ability to acclimatize to Saharan environmental conditions.

Kappa casein (CSN3) gene polymorphism and its effect on cumulative milk yields of Holstein Friesian dairy cattle

Kappa casein (CSN3) is a standout amongst the most vital milk proteins in mammals that assumes a crucial part in milk quality and coagulation. This study aimed to determine genetic polymorphism of the Kappa casein gene (CSN3) and associate its genotype variants on various cumulative milk yields in Holstein Friesian (HF) dairy cattle. A number of 61 blood samples were collected from 2 Holstein Friesian populations, respectively, from IRIAP Breeding Station in Ciawi (61) and Lembang Artificial Insemination Center (Lembang AIC) (17). Real Time -Polymerase Chain Reaction (RT-PCR) method was used to identify variant genotypes of the Kappa Casein gene. In population were detected all three genotypes GG, GT, and TT. The most frequent genotype was TT, with a frequency of 0.63. Results from the statistical association analysis between g.13975G>T CSN3 genotype and cumulative milk yield in standard lactation length were not significant.

Non Genetic Factors Affecting Production and Reproduction Traits of Graded Murrah Buffaloes

Background: Environmental factors play a major role and influence the economically important traits in dairy animals. The present investigation was undertaken to study the influence of season on production and reproduction traits of graded Murrah buffaloes reared under farm conditions. Methods: The data pertaining to 164 graded Murrah buffaloes was utilized to study influence of seasons on various climatic factors like maximum, minimum and mean temperature, relative humidity (morning and evening), rainfall, sunshine, wind speed, evaporation and production and reproduction traits like lactation length, lactation yield, days to attain peak yield, persistency, calving interval, birth weight and number of lactations. Result: The present investigation revealed significant effect of season on all the meteorological parameters, production and reproduction parameters studied. The correlations among meteorological parameters and production and reproduction traits were also significant.

Varimax Rotated Principal Component Analysis of Productive Traits in Nigeria Indigenous Cattle Raised under Semi-Intensive Management System

The objectives of this study were to quantify the production traits using principal component analysis in Bunaji and Gudali cattle. Morphological traits of Body weight (Kg); BL: Body Length (Cm); HW: Height at withers (cm); CW: Chest width (cm); HG: Heart Girth (cm); Rumwi: Rump width (cm); TL: Teat Length (cm); RUH: Rear Udder Height (cm); UC: Udder Circumference (cm) and lactation traits of TY: Total Yield (Litres); ADY: Average Daily Yield (Litres/day) and LL: Lactation Length (days) were measured. To find the traits that were clustered together, data were fed to the principal component matrix of J.M.P genomics statistical software. In general, communalities varied from 0.32 to 0.91, and the proportion of variance accounted for by variables was 48 percent Bunaji, 0.31 to 0.99 for communalities, and 58 percent in Gudali cows. The information on principal component analysis will facilitate their efficient use in breeding programs for genetic gain and genetic improvement programs in indigenous Nigeria cattle.

​Genetic Analysis of Production and Reproduction Traits of Ongole Cattle in an Organized Farm of Andhra Pradesh

Background: The knowledge and estimation of genetic and non-genetic factors on the production and reproduction traits of Ongole cattle are important to enable the breeders to design efficient conservation strategies and adopt better selection methods, management practices and culling operations. Methods: Data available on 220 Ongole cows mated to 22 sires- at the Livestock Research Station, Mahanadi, Kurnool (District), Andhra Pradesh over a period of eight years was used for the present analysis. Result: Results in the present study revealed that performance of animals was improved in lactation milk yield (LMY, 1063.33±31.13), 305 lactation milk yield (LMY, 1019.83±29.22), lactation length (LL, 266.26±5.6), less calving interval (CI, 497.95±8.58), service period (SP, 188.19±5.17) and dry period (DP, 214.79±19.6) compared to earlier reports. Parity and period have shown significant effect on all production traits and calving interval. Effect of season was non-significant on all productive and reproductive traits. Most of the heritability estimates for milk production traits were medium in range but low for reproductive traits. The correlations between productive traits and calving interval were negative.

Devising a Selection Strategy for the Jamunapari Goat for Improving Lactation Performance

This study aims to evaluate the genetic potential of the Jamunapari goat and formulate a new selection strategy for improving the lactation traits. The data set included 4049 phenotypic records for lifetime milk yield at 90 days (MY90) and 140 days (MY140), total milk yield (TMY), and lactation length (LL) obtained from the progeny of 83 sires and 1643 dams between 1990 and 2019. Animal model employing average information restricted maximum likelihood (AIREML) was used to estimate genetic parameters for milk yield traits and LL. The direct additive heritability estimates for lifetime lactation traits, that used repeatability model were 0.10 ± 0.03, 0.08 ± 0.03 and 0.12 ± 0.02 for MY90, MY140 and TMY, respectively, while it was low for LL (0.06 ± 0.02). The repeatability estimates were moderate ranging from 0.17 to 0.22 for milk yield traits and LL, indicating persistent performance over the parities. Animal permanent environment influence (c2) was significant in milk yield attributes, whereas additive maternal genetic effects were absent. As the early selection criteria based on first parity records is essential, we analysed the data for the first parity separately and obtained moderate h2 estimates viz. 0.26 ± 0.05, 0.26 ± 0.06 and 0.25 ± 0.06 for MY90, MY140 and TMY, respectively. These estimates augurs further positive scope of selection in Jamunapari goats for higher milk yield. High and positive genetic correlation of MY90 with MY140 (0.97 ± 0.01) and TMY (0.91 ± 0.05) revealed the scope of using MY90 as the selection criterion.Based on these results, we recommend use of MY90 as a single trait selection criterion for genetic improvement of all lactation traits in Jamunapari goat.

Analysis of the Non-genetic Factors Influencing the Performance of High-grade and Inter se Mated Crossbred Dairy Cows at Holetta Dairy Research Farm, Ethiopia

Background: The effect of non-genetic factors including feeding, management, climate, calving year, season and others on animal production improvement has attracted considerable attention in recent years. In addition to improving animal genetics, the importance of optimum environmental conditions in enhancing animal production is recognized. Methods: Data collected from 2008 to 2018 on 2036 records from crossbreeding dairy cattle herd at Holeta Agricultural Research Center were analyzed to evaluate the genetic and non-genetic environmental effect on lactation milk yield (LMY), lactation length (LL) and calving interval (CI). The fixed effect used in the data analysis were breed group, parity, years group of calving and seasons of calving. GLM procedure of SAS was used to analyze the data. Result: Results of data analysis indicated that breed group and year group of calving had a significant (P less than 0.05) effect on LMY, LL and CI. Parity significantly (P less than 0.05) affected LMY and CI but had no significant effects on LL. While, season of calving had no significant influence on all traits. Least square mean LMY was significantly (p less than 0.05) highest (3191 kg) for 75% first generation breed group and significantly (P less than 0.05) lowest for pure Ethiopian Borena breed (124 kg LMY). Mean LL was significantly (p less than 0.05) highest (354 days) for 75% first generation breed group and significantly (P less than 0.05) lowest for pure Ethiopian Borena breed (178 days). Least square mean CI was significantly (p less than 0.05) longest (477 days) for 75% first generation breed group and significantly (P less than 0.05) shortest (422 days) for 75% inter se mated breed group. Among 75% crosses, the 75% inter se mated breed group had lower LMY (2553 kg) and shorter CI (422 days) compared to 75% first generation breed group. The decline in LMY and CI for 75% inter se mated breed group by 637 kg (25%) and 54 days (13%), respectively compared to 75% first generation, which can be attributed to recombination effect.