Genetic parameters were estimated for birth weight and weaning weight from three year (1991)(1992)(1993) data totalling 1100 records of 25 rams to 205 ewes of Indigenous Sabi flock maintained at Grasslands Research Station in Zimbabwe. AIREML procedures were used fitting an Animal Model. The statistical model included the fixed effects of year of lambing, sex of lamb, birth type and the random effect of ewe. Weight of ewe when first joined with ram was included as a covariate. Direct heritability estimates of 0.27 and 0.38, and maternal heritability estimates of 0.24 and 0.09, were obtained for birth weight and weaning weight, respectively. The total heritability estimates were 0.69 and 0.77 for birth weight and weaning weight, respectively. Direct-maternal genetic correlations were high and positive. The corresponding genetic covariance estimates between direct and maternal effects were positive and low, 0.25 and 0.18 for birth weight and weaning weight, respectively. Responses to selection were 0.8 kg and 0.14 kg for birth weight and weaning weight, respectively. The estimated expected correlated response to selection for birth weight by directly selecting for weaning weight was 0.26. Direct heritabilities were moderate; as a result selection for any of these traits should be successful. Maternal heritabilities were low for weaning weight and should have less effect on selection response. Indirect selection can give lower response than direct selection.

Sheep production is affected by genetic and non-genetic factors. A knowledge of these factors is essential for efficient management and for the accurate estimation of breeding values. The objective of this study was to establish the non-genetic factors which affect birth weight and weaning weight in Dorper, Mutton Merino and indigenous Sabi sheep breeds. A total of 2,625 birth and weaning weight records from Grasslands Research Station collected from 1991 through 1993, were used. The records were collected from indigenous Sabi (939), Dorper (807) and Mutton Merino (898) sheep. A mixed classification model containing the fixed effects of year, birth status and sex was used for identification of non-genetic factors. Sire within breed was included as a random effect. Two factor interactions and three factor interactions were important in indigenous Sabi, Mutton Merino and Dorper sheep. The mean birth weights were 4.37±0.04 kg, 4.62±0.04 kg and 3.29±0.04 kg for Mutton Merino, Dorper and Sabi sheep, respectively. Sire had significant effects (p<0.05) on birth weight in Mutton Merino and indigenous Sabi sheep. Year of lambing had significant effects (p<0.05) on birth weight in indigenous Sabi, Mutton Merino and Dorper sheep.The effect of birth status was non significant in Dorper and Mutton Merino sheep while effect of birth status was significant on birth weight in indigenous Sabi sheep. In Indigenous Sabi sheep lambs born as singles (3.30±0.05 kg) were 0.23 kg heavier than twins (3.07±0.05 kg), in Mutton Merino lambs born as singles (3.99±0.08 kg) were 0.07 kg heavier than twins (3.92±0.08 kg) and in Dorper lambs born as singles (4.41±0.04 kg) were 0.02 kg heavier than twins (4.39±0.04 kg). On average males were heavier than females (p<0.05) weighing (3.32±0.04 kg vs. 3.05±0.07 kg) in indigenous Sabi, 4.73±0.03 kg vs. 4.08±0.05 in Dorper and 4.26±0.07 kg vs. 3.66±0.09 kg in Mutton Merino sheep. Two way factor interactions of sire * year, year * sex and sex * birth status had significant effects (p<0.05) on birth weight in indigenous Sabi, Mutton Merino and Dorper sheep while the effect of year * birth status was non significant on birth weight in Indigenous Sabi sheep. The three way factor interaction of year * sex * birth status had a significant effect (p<0.01) on birth weight in indigenous Sabi and Mutton Merino. Tupping weight fitted as a covariate had significant effects (p<0.001) on birth weight in indigenous Sabi, Mutton Merino and Dorper sheep. The mean weaning weights were 17.94±0.31 kg, 18.19±0.28 kg and 14.39±0.28 kg for Mutton Merino, Dorper and Indigenous Sabi sheep, respectively. Effects of sire and sire * year were non significant on weaning weight in Dorper and Mutton Merino while year, sex and sex * year interaction had significant effects (p<0.001) on weaning weight. On average males were heavier than females (p<0.001) at weaning. The respective weaning weights were 18.05±0.46 kg, 18.68±0.19 kg, 14.14±0.15 kg for males and 16.64±0.60 kg, 16.41±0.31 kg, 12.64±0.32 kg for females in Mutton Merino, Dor...

Goat-centered approach can transform rural agrarian households and communities toward gender inclusive climate change adaptation in agriculture to enhance food security and nutrition in Sub Saharan Africa. Gender inequality, climate change effect and food and nutrition insecurity are the most defining and deeply intertwined socio-economic and environmental challenges in rural communities in sub Saharan Africa. This chapter offers an overview of potentiality of goat rearing as a sustainable and holistic approach in addressing triple challenges of gender inequality, climate change effects and food and nutrition insecurity in rural communities. The failure to address gender inequality and deal with the climate change effect has thrown the Sub-Saharan Africa into a state of perpetual food scarcity due to compromised food production, consequently condemning the rural communities and its people to extreme poverty and nutrition insecurity. Because of this scenario, a number of both internal and external development agencies, have put several measures in place to alleviate the situation, which has for long preyed upon the region and continues to frustrate food stability in the region. The total failure of the previous autonomously attempt to address the triple challenges of gender inequality, climate change effects and food and nutrition insecurity at the household level give ground to prominence on the endorsement of more sustainable and multifaceted approaches. A proposition is made that goat rearing is one such initiative, which combines the empowerment of women in agriculture to ensure availability of the basic food needs of the household, while sustaining animal production due to goat’s adaptability to the climate induced harsh environmental conditions. The goat centered multifactorial approach to address the triple challenges is focused on the exploitation of the interlinkages among these socio-economic and environmental ills. The major assumption is that goat rearing in rural economies simultaneously curtails the risk of food and nutrition insecurity by acting as an entry point of gender equality, while leveraging on the opportunities that goat rearing will effectively offset adversities posed by the climate change effect. In most instances, women are potentially more vulnerable compared to men as they directly experience the ponderous effects of climate change in agricultural production, in turn compromising food and nutrition security. Goat rearing is central in the removal of systemic barriers that hold women back from equal participation in agriculture, by broadening their socio-economic opportunities, hence, playing a significant role in agricultural value-chains. The goat-rearing sustainability concept is based on establishing and maintaining the circumstances under which people and nature can subsist in productive harmony, that allow fulfilling the social, economic, and other requirements of present and future generations. Despite the climate change adverse effects, the goat population has continued to proliferate in harshest agro-ecological regions, which demonstrate that goats have managed to adapt to the current unfriendly climate induced environmental conditions. It is assumed that promoting goat rearing will narrow the gender equality gap between men and women, and enhance the participation of women in agriculture, hence, improving productivity, and food and nutrition security. Goats due to their numerical population advantage and deeply embedment in rural communities have constantly contributed to rural poor resource farmers’ livelihoods in many ways, and their contributions tend to be significant. This chapter offers an overview of potentiality of goat rearing as a sustainable and holistic approach in addressing triple challenges of gender inequality, climate change effects and food insecurity in rural communities of Sub Saharan Africa.

Pedigree yearling records from 1021 local Tuli calves born at Matopos Research Station were analyzed for non genetic factors, genetic parame ers and trends on the yearling weight. It was found that s re year of b rth, sex of calf age of dam had s gn f cant effect (p < 0.01) on a growth trait. The nconsistency o literature estimates indicated the importance o est mation o environmental factors that affect yearling weight within specific experimental herds and environment. Model incorporating both direct and maternal additive genetic effect, covariance and correlations of direct-maternal and permanent environmental maternal effects was adopted for the study Direct and maternal heritabi ty est mates of 0.18 ± 0.001 and 0.04 ± 0 001 were observed, respect vely. Direct-maternal genetic correlat on was low and posi ve, 0.07± 0.012. The regression of average direct breeding values on year was almost zero and the regression of average maternal breeding values on year 0.03 kg/yr. Correction of environmental effects was necessary to increase accuracy for selection of yearling weight in local Tuli cattle. Maternal genetic effects should be included in a model of covariance components estimation at 12 months of age.

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