Lactation responses of Holstein dairy cows to supplementation with a combination of trace minerals produced using the advanced chelate compounds technology.

Advanced chelate compounds technology is a novel technology that introduces a new generation of chelates to deliver trace elements better by polymerization of organic acids. In the present study, the over-supplementation effect of Bonzaplex7 supplement, which is designed based on the aforementioned technology, was evaluated on milk yield of dairy Holstein cattle through two experiments. In the first experiment (exp. I), 24 primiparous dairy cows were randomly assigned to one of 3 groups: (1) without over-supplementation (control); (2) daily allowance of 7 g/cow Bonzaplex7 containing Co (12 mg), Cr (3.5 mg), Cu (126 mg), Fe (56 mg), Mn (196 mg), Se (2 mg), and Zn (357 mg) (Bonzaplex7); and (3) daily allowance of the same amounts of all of the trace minerals in amino acid complex form (AA). In the second experiment (exp. II), 170 multiparous dairy cows received either 7 g/day/cow Bonzaplex7 (85 cows, test) or no additional supplement (85 cows, NS). In exp. I, the milk yields in control, Bonzaplex7, and AA were 34.30, 36.46, and 35.83 kg/day, respectively (P = 0.528). No significant differences in milk composition were detected among the groups. In exp. II, however, higher milk fat and energy-corrected milk yield were observed in test compared with NS. Both Bonzeplex7 and AA elevated the plasma concentrations of Cu, Mn, and Se. The results provided evidence that supplementing dairy cows with a combination of trace minerals which produced using the advanced chelate compounds technology has a potential to improve milk fat and to decrease disease susceptibility under stressed conditions.

Variation in Weed Seed Fate Fed to Different Holstein Cattle Groups.

Weed seeds may maintain their viability when passing through the digestive tract of cattle and can be therefore dispersed by animal movement or the application of manure. Whether different cattle types of the same species can cause differential weed seed fate is largely unknown to us particularly under non-grazed systems similar to Holstein-Friesian dairy farming. We investigated the effect on the seed survival of four weed species in the digestive tracts of four groups of Holstein cattle: lactating cows, feedlot male calves, dry cows and growing heifers. The weed species used were Cuscuta campestris, Polygonum aviculare, Rumex crispus and Sorghum halepense. Cattle excretion was sampled for recovery and viability of seeds at four 24 hourly intervals after seed intake. The highest seed recovery occurred two days after seed intake in all cattle groups. Averaged over weed species, dry and lactating cows had the lowest and highest seed recovery of 36.4% and 74.4% respectively. No significant differences were observed in seed recovery of the four weed species when their seeds were fed to dry cows. Based on a power model fitted to seed viability data, the estimated time to 50% viability loss after seed intake, over all cattle groups ranged from 65 h (R. crispus) to 76 h (P. aviculare). Recovered seeds from the dung of feedlot male calves showed the highest mortality among cattle groups. Significant correlation was found between seed viability and ruminal pH (r = 0.86; P<0.05). This study shows that management programs aiming to minimize weed infestation caused by livestock should account for the variation amongst cattle groups in seed persistence. Our findings can be used as a guideline for evaluating the potential risk of the spread of weeds via the application of cattle manure.