The diurnal patterns of ruminal enzymatic activity and in vitro digestibility of starch, neutral detergent fiber, and protein.

The objective of this study was to determine whether diurnal patterns in starch, neutral detergent fiber (NDF) and protein digestibilities and amylolytic, fibrolytic, and proteolytic activities exist in dairy cows. Rumen fluid was collected from 4 ruminally cannulated Holstein dairy cows before the morning feeding and subsequently every 4 h for a 24-h period. Two of the cows were restricted from feed for 8 h overnight, and the other 2 continued to receive their feed ad libitum, to isolate and quantify the effects of changes in feeding behavior at night. After 2 runs the cows were crossed over between night feeding treatments. Rumen fluid was analyzed for enzymatic activity and in vitro starch, NDF, and nitrogen digestibility. Circadian rhythm analyses of enzymatic activity and in vitro digestibility were conducted by fitting the linear form of a cosine function with a 24-h period. Patterns were observed in activity for amylase, lichenase, endoglucanase, and xylanase, with the highest activities observed at the time points subsequent to milking and feed delivery. Protease activity was unaffected by either feeding treatment or possible feeding behavior. When fitted to a cosine function, all the parameters tested followed a daily pattern that was sensitive to the overnight availability of feed, although the parameters responded differently to the feeding treatment. The patterns displayed by in vitro digestibility results of starch, NDF, and nitrogen, across the various fluid collection time points, were highly variable. The time at peak (acrophase) observed in the enzymatic analysis did not correspond to those observed in the in vitro analysis. These results suggest that different interpretations should be given to enzymatic activities and in vitro digestibility values, and the time of rumen fluid collection relative to feeding time should be considered and reported when rumen fluid is used for research or commercial purposes. Maximum digestibility appears in fact to be reached around 4 to 5 h after the main ration delivery for NDF and starch and around ration delivery for protein.

Review on the status of goat production, marketing, challenges and opportunities in Namibia.

This paper presents the current status of goat production and marketing in Namibia and its challenges and opportunities. Livestock data and reports from the Directorate of Veterinary Services, Meat Board of Namibia and Namibia Statistics Agency were analysed to establish the current status in goat production and marketing. Namibia has 1.9 million goats of which 54% of the total number is found in the northern communal areas. In the commercial farming sector, Boer goat is the main established breed for meat production, while in northern communal areas, the local indigenous goats are common. Goats are reared under an extensive production system and fully dependent on rangelands. Marketing of goats in the formal market is regulated by the board of the red meat industry, whereas there is no regulated marketing in the informal market. The main purpose of goats farming in communal areas is rather for home consumption; thus, trading becomes secondary when a need for emergency income arises. In the commercial sector, goats are mainly marketed on hoof to the lucrative South African market. The major challenges for goat production are recurrent drought, diseases and parasites, predators and theft and poor management. Organized marketing in communal areas and lack of marketing infrastructure are impeded by small flock sizes that limit the numbers that can be marketed. Consumers' health consciousness provides an opportunity to increase goat production through increased demand for goat meat and milk. Market incentives such as attractive prices, market infrastructure, value addition and support policies for local farmers are imperative to improve goat production and marketing.