• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 1
  • Tagged with
  • 11
  • 11
  • 11
  • 5
  • 4
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Time budgets, avoidance distance scores-related behaviour and milk yield of pasture-based Jersey, Friesland and cross bred cows

Dodzi, Madodana Sunson January 2010 (has links)
Time budgets, avoidance distance scores-related behaviour and milk yield of pasture-based Jersey, Friesland and crossbred cows. by Madodana Sunson Dodzi The study was conducted at the University of Fort Hare farm to determine the time budgets, the avoidance-related behaviour variables and their relationship with milk yield in three pasturebased dairy genotypes: Jersey, Friesland and crossbreed. Twenty one clinically health dairy cows aged between 52 and 55 months, in mid lactation and comprising of seven cows from each genotype were used in the study. The time spent on different activities (grazing, lying down, standing and others) at pasture was recorded using stop watches across four seasons. The behavioural responses of the three genotypes to humans were determined by recording their avoidance distance scores (AD), exit speed (ES), pen scores (PS), pen behaviour scores (PBS), plat form scores (PLS) and the occurrence of kicking (KCK) and stepping (SPG) during milking on four consecutive days in four seasons. Time spent standing was higher (P < 0.05) for Friesland compared to Jersey and crossbred during the hot-wet season. In the cool-dry season the Jersey spent more time (P < 0.05) grazing than the other breeds. The Friesland and crossbred on the other hand devoted most of their time lying down compared to Jersey in the cool- dry season (P < 0.05). There were season differences in time spent on all activities (P < 0.05). Time spent on grazing was longest in post-rainy seasonal and lowest in hot- wet season (P < 0.05). The longest lying down period was observed in the hot-dry season and lowest in hot-wet season (P < 0.05). iii Daily milk yield Varied (P < 0.05) with genotype with the Friesland and Jersey producing higher yield than the crossbred. The highest amount was produced in hot-dry and the least in hot-wet season. Milk yield was positively correlated (P < 0.05) with lying down. Standing was negatively correlated with milk yield (P < 0.05). The Friesland had the highest avoidance distance scores (P < 0.05) and the Jersey had the lowest avoidance distance scores in all seasons. There was an association (P < 0.05) between genotype and exit speed scores, pen scores and stepping behaviour scores. The Friesland exhibited the highest exit speed scores than the other breeds. The Jersey had the lowest (P < 0.05) kicking behaviour scores. There was a relationship (r = 0.64) between avoidance distance scores and exit speed. Exit speed scores were correlated with pen score(r= 0.23). Milk yield was significant related (r= 0.17) to the occurrence of kicking behaviour. The genotypes showed different levels of sensitivity to season and milk yield was influenced by breed and season. It can be concluded that time budgets vary with season and farmers need to adopt measures that buffer the effect of season on welfare of dairy cows. It can also be concluded that avoidance distance scores differs according to genotype with Jersey being more confident to humans than other two breeds. It is therefore recommended that provision of shades or cooling mechanism should be adopted to buffer the effects of hot-wet season. Improving quality of feed during the cool-dry season may be critical for Jersey cows. Finally positive handling of the dairy cows is recommended in order to improve the welfare and milk yield of pasture based dairy cows.

Page generated in 0.0578 seconds