Intake of lick block supplements by cattle grazing native monsoonal tallgrass pastures in the Northern Territory.

Abstract

Four supplementation treatments to investigate wet seasons responses were imposed on eight Brahman/Shorthom cross herds totalling 870 animals of all classes (cows and calves, bulls, heifers and steers). They grazed 12,300 ha of native pasture in the Darwin district of the Northern Territory. The treatments were: (i) control (no wet season supplement), (ii) Mineral (Ultraphos - supplementation with 13 minerals during the wet season), (iii) +Protein (Ultrapro-50 - the same 13 minerals plus non-protein nitrogen (WN) and true protein over the wet season), and (iv) Strategic (strategic use of salt, mineral and hTN supplements over the early wet, mid wet and late wet seasons respectively). All treatments received an hTN plus mineral supplement (Uramol) during the dry season. Supplement intakes by the herds were measured monthly for three years. Intake of Salt, Ultraphos and Ultrapro-50 supplements averaged 43, 124 and 149 g/animal/day respectively during the three wet seasons. Losses of the molasses-based block formulations due to rain were small (7%) during the wet season. However, up to one third of each pure salt block was eroded. Intake of Uramol during the three dry seasons averaged 182 g/animal/day across all herds. No urea toxicity problems were noticed over the three years of the supplement programme, despite high intakes during the dry season. All animals consumed some supplement. However, levels of supplement intake: (i) increased with the seasonal decrease in native pasture quality, (ii) decreased with an increase in proportion of paddock burnt, (iii) varied between animal classes, with lactating cows consuming 64% more supplement than non-lactating cows in two of the three years, and (iv) varied between individuals within classes. Individual intake varied widely (from 10 to 835 glanirnallday for lactating cows) with no significant correlation between individual intake and the pregnancy rate or average daily liveweight gain.

Seasonal and Nutrient Supplement Responses in Rumen Microbiota Structure and Metabolites of Tropical Rangeland Cattle

“…As expected, supplementation with non-protein nitrogen to cattle grazing low quality tropical pastures had a remarkable response on body weight and shifted the rumen fermentation profile. The ADWG of the supplemented pregnant heifers increased over 0.500 kg per day, which is greater than that in previous published studies [ 2 , 9 , 10 , 11 , 39 , 45 ]. However, these studies reported a less acute loss of weight, maintenance, or increases up to 0.300 kg per day in cattle supplemented with urea and other micronutrients (e.g., sulfur) during the dry season.…”

Lithium salts as a marker of intake of supplements by cattle

“…Many animals may not consume any supplement, while among those that do consume there may be high variability in supplement intake (Arnold and Maller 1974;Nolan et al 1975;Murray et al 1978;Eggington et al 1990;Bowman and Sowell 1997). Variability in intake of supplements is likely to be particularly high when mineral and non-protein nitrogen supplements are provided ad libitum as loose mineral mix or solidified feed blocks to grazing animals (Dixon and Petherick 1996;Dixon and Smith 2000;Dixon et al , 2001).…”

Microelement Supplementation in Dairy Cows by Mineral Lick

“…In another study dealing with molasses blocks (Graham et al 1977) the consumed amount varied between 0 and 387 g·day -1 . Eggington et al (1990) found even bigger variation -they described the range in acceptance of salt block between 10 g and 835 g·day -1 . Apart from variations in the amount of lick intake, there were variations in the acceptance of molasses blocks (of identical composition) made by different manufacturers (Ducker et al 1981;Kendall et al 1983).…”