A study was carried out at a 2,200 sow farrow-finisher facility in Zimbabwe to determine the main reasons for sow removal and the season when removal was most common. Data on the number of sows culled and the reasons for culling as well as mortalities was recorded weekly for a 12-month period. The culling frequency was 52.8 % (n = 1 162). Descriptive statistics indicated that reproductive problems accounted for 70.8 % (n = 823) of sow removals, death (15.6 %, n = 181), lameness (4.6 %, n = 53), miscellaneous (2.5 %, n = 29), production (2.2 %, n = 26), peripartum (2.2 %, n = 25) and age (2.2 %, n = 25). The results also showed that culling was highest in gilts and primiparous sows (41.3 %, n = 480) with the least culling being observed in sows in parity 7 (5.3 %, n = 61). The hot wet season was observed to be the one when culling was most common (33.5 %, n = 389) with the least being in the cold dry season (17 %, n = 198). It was concluded that most of the sow removal was unplanned. There is a need to improve replacement gilt selection, reproductive efficiency, health and nutrition management to increase productivity in a sow unit.

An experiment was conducted to determine the optimum inclusion levels of dried broiler litter (DBL) as a substitute for cottonseed cake (CSC) in fattening diets for Brangus steers. Thirty Brangus steers were randomly allocated to five groups of six animals each. Each group was fed one of the experimental diets which had CSC substituted for DBL at levels of 0 (DBL0), 50 (DBL50), 100 (DBL100), 150 (DBL150) and 200 g/kg (DBL200). Average daily gain (ADG), dry matter intake and live weight gain (LWG) were measured over a period of 90 days, and the results were analysed using the MIXED procedures of SAS. Linear and quadratic effects of DBL inclusion on dry matter intake, LWG and ADG were also determined. Results showed interactions between diet and time that significantly affected ADG and LWG (p < 0.05). Both ADG and LWG decreased with increases in DBL inclusion with the depressed performance becoming more pronounced with time. Linear and non-linear decreases in LWG and ADG, respectively, were observed with increasing levels of DBL. The DBL50 diet resulted in performance that was similar to DBL50 and was 4% cheaper. Broiler litter can be used as a supplement for conventional protein sources, but at higher inclusion levels, it needs to be augmented by increased fermentable energy.

Nitrogen (N) fertilization influences woody plant growth, foliar nutrient and antinutrient concentrations. We conducted a nursery experiment to determine the effect of five N fertilization rates on Dichrostachys cinerea and Acacia karroo sapling height, basal diameter, growth of longest shoots and root length, crude protein (CP), acid and neutral detergent fiber (NDF), condensed tannins (CT) and total phenolic (TP) concentrations. Eight potted plants of each woody species were allocated to each of five N fertilization rates (0, 0.21, 0.42, 0.63 and 0.84 g N/kg of soil) in a completely randomized design. Different N fertilization rates did not result in varying plant growth in terms of height, stem diameter and root length in both D. cinerea and A. karroo. However, N fertilization rate of 0.63 g N per kg of soil resulted in an increase in length of the longest shoot in both D. cinerea and A. karroo. Foliar CP increased with an increase in N fertilization rate up to 0.63 g N per kg of soil, while acid and NDF, CT and TP were lowest at N fertilization rates of 0.63 g N per kg of soil in both D. cinerea and A. karroo. We conclude that N did not limit plant growth, and therefore N fertilization is unlikely to significantly improve sapling growth. However, N fertilization improved foliar CP and reduced CT and TP concentrations in both D. cinerea and A. karroo improving their nutritive value to browsers. K E Y W O R D Scarbon-based plant secondary metabolites, crude protein, fiber, nitrogen-fixing, plant height

No abstract

Broad- and fine-leaved woody species respond to seasonal changes from wet to dry season differently. For example, broad-leaved species shed their leaves earlier, while fine-leaved species, especially acacias retain green foliage well into the dry season. These differences are expected to result in variation in selection of broad- and fine-leaved woody species as browse by free-ranging goats. We tested the hypothesis that free-ranging goats select broad-leaved woody species more than fine-leaved species during wet (growth) season and fine-leaved woody species more than broad-leaved species during dry season. In addition, we tested if broad- and fine-leaved woody species had different foliar dry matter digestibility and chemical composition (crude protein, neutral detergent fibre, acid detergent fibre, total phenolics and condensed tannins concentration). Free-ranging goats were observed foraging on broad- and fine-leaved woody species over a two-year period (2014 and 2015) during three seasons: early wet (October/November), late wet (February/March) and dry (May/June). Ivlev’s selectivity or Jacob’s index (Ei) was calculated for five woody species (two broad-leaved and three fine-leaved) browsed by goats during wet and dry season. Jacob’s selectivity index was higher for broad–leaved (Ziziphus mucronata and Searsia (Rhus) tenuinervis) than fine-leaved woody species (Acacia nilotica, Acacia karroo and Dichrostachys cinerea) during wet season. However, the trend was reversed during dry season with fine-leaved species having higher Jacob’s selectivity index than broad-leaved species. Leaf dry matter digestibility and chemical composition was similar between broad- and fine-leaved woody species throughout the year. We conclude that goats selected broad-leaved woody species during wet season when browse was plentiful and then switched to fine-leaved species which retained leaves during dry season.