Thesis and Dissertations

Evaluating Synergies of Genetic and Non-Genetic Intervention on reproductive and Productive Performance of Crossbred Dairy Cows under Smallholder Farmers Condition in Selected Milk Shed areas of Ethiopia

2024-03-01T00:00:00Z

Evaluating Synergies of Genetic and Non-Genetic Intervention on reproductive and Productive Performance of Crossbred Dairy Cows under Smallholder Farmers Condition in Selected Milk Shed areas of Ethiopia Zenebe, Tesfa Dairy cattle genetic improvement has been practiced so far in Ethiopia to improve the productive and reproductive performance of dairy cows. However, the achievement has been limited due to poor husbandry practice, shortage of feed, inappropriate breeding scheme, inefficient AI service, and mismatch between management and genetic intervention under smallholder farmers conditions. This study was aimed to investigate the synergetic effect of genetic and non-genetic factors on reproductive and milk production performance of crossbred dairy cows under smallholder dairy farmer’s condition in selected milk shed areas of Ethiopia. A total of 72 smallholder dairy farmers who had at least two crossbred dairy cows and recruited, and non-recruited by different projects were purposively selected from three administrative regions of Ethiopia (Amhara, Oromia and South Nation, Nationalities, and Peoples). During the intervention period, this study had two phases. In first phase, the selected smallholder dairy farmers were assigned in to three treatment groups (T1 (control), T2 (previously trained by the projects) and T3 (received additional enhanced training and improved feed input). In second phase, treatment groups that were regarded as control (T1) during the first phase had received enhanced training and improved feed input following the same protocols with previous one. On the other hand, treatment groups that were received enhanced training and improved feed input (T3) considered as control treatment group for the second phase intervention study. Tail hair samples for genetic profiling of breed composition were collected from all experimental cows in the study. According to their Holstein Frisian blood level, crossbred cows were classified into four genetic groups (<25%, 25-50%, 51-75% and >75%). In addition, experimental cows were also grouped based on their parity. Performance data collection was collected over for the period of three years starting from 2020 to 2022. A general linear model procedure of the statistical analysis system (SAS version, 9.0) ix was used to analyse the reproductive and productive performance data. The analysis of variance showed that statistically non-significant(P>0.05) difference was observed for the effect of genotype by treatment and genotype by parity interactions on age at first service (AFS), age at first calving (AFC), calving interval (CI), days open and number of services per conception (NSPC) traits and some milk production traits such as lactation length (LL) and first lactation length (FLL). The results of fixed effect analysis revealed that the influence of genotype had a significant effect in age at first service (P<0.0001), age at first calving (<0.0001), calving interval (<0.01) and number of services per conception (<0.001) traits. However, a statistically non-significant (p>0.05) difference was observed for the main effect of treatments on age at first service (AFS), age at first calving (AFC), calving interval (CI), and number of services per conception (NSPC) traits. The study also revealed that calving interval (p<0.01) and days open (p<0.05) traits were significantly influenced by the interaction effect of treatment and parity interaction. The analysis of variance showed that the interaction effect of genotypes by treatments and genotype by parity caused significant (p<0.0001) in lactation milk yield and daily milk yield traits. In addition, first lactation milk yield (p<0.001) and first lactation daily milk yield (p<0.01) traits were significantly influenced by the interaction effect of genotypes and treatments. Lactation length was significantly influenced by the main effect of genotype (p<0.0001) and treatment (p<0.001). A statistically significant effect of genotypes (p≤ 0.01) and treatments (p≤0.001) were observed on first lactation milking days trait. The overall least square mean value of first lactation milk yield, first lactation daily milk yield and first lactation length for the interaction effect of genotype and treatments were 2297.0 ±53.42 liters, 7.3 ± 0.15 liters and 309.0±2.00 days, respectively. The overall least square mean value of daily milk yield, lactation length and lactation milk yield for the interaction effect of genotype by treatment and genotype by parity were 8.0±0.16 liters, 298.2±2.51 days and 2419.8 ± 61.56 liters, respectively. In conclusion, the combined effect of genetic and non-genetic intervention under smallholder farmers condition resulted in increased milk production performance of primiparous and multiparous crossbred dairy cows. However, no significant difference was observed in reproductive performance of crossbred for synergetic effect of those factors.

Phenotypic Characterization and Identification of Breeding Objectives of Indigenous Goats in Raya Kobo District, North Wollo, Amhara Region, Ethiopia

2022-08-01T00:00:00Z

Phenotypic Characterization and Identification of Breeding Objectives of Indigenous Goats in Raya Kobo District, North Wollo, Amhara Region, Ethiopia Tesfamichael Assefa The study was carried out to characterize the indigenous goat populations and identify breeding objectives of goat keepers in Raya Kobo district. The study area was selected based on the distribution of goat population and agro-ecology. A total of 180 households were randomly selected to study goat production system. The data were collected through four approaches; formal personal interview (questionnaire), focus group discussion, measurement of morphological traits of live animals, observation, and own flock ranking methods. Morphological traits were measured from 510 goats and a total of 60 households having at least five does were participated on own flock ranking. Descriptive statistics and chi-square test were implemented using SAS (2002) for categorical traits and the quantitative data were analyzed through the GLM procedures of SAS. Indices were calculated for all ranking data. The result revealed that goat is the second most economically important livestock species next to cattle in the lowland and midland areas. Income generation and home meat consumption are the major reason of keeping goat in all study areas. Anfit (Pasteurellosis), Fentata (Goat pox) and Entutie (Anthrax) were the economically important diseases in the study areas with index value of 0.298, 0.172 and 0.168, respectively. The kidding pattern seems to be affected by agro-ecology. In the lowland areas, the majority of kidding occurred in January followed by September and July. However, in the midland and highland areas, September, October and January were ranked 1 st , 2 nd , and 3 rd . About 65% of goat keepers in the lowland and 76.5% in the midland had their own buck. The mating method in all study areas was uncontrolled natural mating method. The mean ages of buck selection were 9.08±0.39, 7.01±0.51, and 8.10±0.39 months in the highland, lowland and midland areas, respectively. The mean service length of breeding bucks were 2.56±0.15, 2.57±0.18, and 1.85±0.17 years for highland, lowland and midland areas, respectively. The overall mean age at first service for female, age at first kidding, kidding interval, frequent type of birth, reproductive age of doe, number of kids born per lifetime were 8.49±0.16 months, 13.5±0.16 months, 8.73±0.11 months, 1.46±0.03 kids, 6.78±0.11 years, and 10.5±0.14 kids, respectively. The overall mean (±SE) market age for male and female goats were 8.88±0.17 and 9.28±0.16 months, respectively. Feed shortage, diseases prevalence, drought, and labor shortage were the most limiting factors for goat production although their importance was not similar across agro-ecologies. The dominant coat color type of goats was gray (26.47%), light red (26.08%), white and red (12.55%), and deep red (10.39%). All goats in the highland and midland and most (95.9%) of goats in the lowland had horn. Hanged downear orientation (48.7%) is a dominant type in the highland areas. However, in the lowland and midland areas, most (60.4%) goats had lateral ear orientation. Most (97.3% of female and 61.9% of male) of goats had a straight facial profile. Sex, age and agro-ecology had a significant effect on live weight and most morphological traits. Most linear body measurements increased with age of goats. In this study, all morphological traits were positively and significantly correlated with live weight (r = 0.44 to 0.91, P <0.001) of female goats. The live weight of males was positively and significantly correlated (r = 0.25 to 0.91) with all morphological traits. Although six to seven traits significantly contribute to the model, chest girth (CG) and wither height (WH) were the utmost importance in the prediction of live weight of female (R 2 = 0.825) and male (R 2 = 0.830) goats, respectively. Most (90 to 96.7%) of goat keepers select male goats to be a parent for the next generation. Similarly, about 91.3% of the goat keepers in the highland and all goat keepers (100%) in the lowland select best breeding goats. The breeding objectives of goat keepers were identified using interview and own animal ranking approaches. Coat color, appearance, twinning ability, milk yield and kid growth were identified as breeding objective for does through personal interview. Similarly, coat color, appearance and growth were the most important traits for male selection. According to own animal ranking, coat color, appearance, milk yield, twining ability and mothering ability were the most important traits with index values of 0.357, 0.301, 0.150, 0.148, and 0.045, respectively. Own animal ranking result indicated that the first preferred does had higher values for morphological traits and market price compared to 2 nd , 3 rd selected, and inferior does. Thus, two breeding objective identification methods could be used in combination to reveal the breeding objectives of goat keepers properly.