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

Effects of Complete Vitamin and Mineral Supplementation in Full Potential All-milk Diets on Growth and Health of Holstein Bull Calves

Pre-ruminant Holstein bull calves were fed two diets of pasteurized whole milk (PWM) in amounts that either limited intake or that maximized intake according to common commercial practice. Diets then were either supplemented or not supplemented with a full complement of vitamins and trace minerals (VTM) that met or exceeded NRC requirements. The objective of the study was to quantify the effects of the four feeding strategies on growth of calves, vitamin and mineral statuses in blood, and magnitude of acute phase inflammatory protein expression in response to lipopolysaccharide (LPS) exposure. Calves were assigned randomly to one of four treatment groups (LM-, low milk, not VTM supplemented; LM+, low milk, TMV supplemented; HM-, high milk, not VTM supplemented; HM+, high milk, TMV supplemented) for 15 days. The HM strategy increased average daily gain in calves, but VTM supplementation did not improve growth during the first two weeks of life. Calves fed more milk had greater magnesium and copper concentrations in blood plasma, but treatment groups did not differ in acute phase protein expression

Effects of Complete Vitamin and Mineral Supplementation in Full Potential All-milk Diets on Growth and Health of Holstein Bull Calves

Pre-ruminant Holstein bull calves were fed two diets of pasteurized whole milk (PWM) in amounts that either limited intake or that maximized intake according to common commercial practice. Diets then were either supplemented or not supplemented with a full complement of vitamins and trace minerals (VTM) that met or exceeded NRC requirements. The objective of the study was to quantify the effects of the four feeding strategies on growth of calves, vitamin and mineral statuses in blood, and magnitude of acute phase inflammatory protein expression in response to lipopolysaccharide (LPS) exposure. Calves were assigned randomly to one of four treatment groups (LM-, low milk, not VTM supplemented; LM+, low milk, TMV supplemented; HM-, high milk, not VTM supplemented; HM+, high milk, TMV supplemented) for 15 days. The HM strategy increased average daily gain in calves, but VTM supplementation did not improve growth during the first two weeks of life. Calves fed more milk had greater magnesium and copper concentrations in blood plasma, but treatment groups did not differ in acute phase protein expression.</p

Relationship between seed viability and ruminal pH of four Holstein cattle groups.

<p>Relationship between seed viability and ruminal pH of four Holstein cattle groups.</p

Changes in viability of the four weed seeds over time (as h after seed intake) for four groups of Holstein cattle.

<p>Symbols are observed data and lines are fitted values obtained from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154057#pone.0154057.e004" target="_blank">Eq 4</a>.</p

Relationship between seed recovery and seed viability for data collected over four consecutive days.

<p>Relationship between seed recovery and seed viability for data collected over four consecutive days.</p

Time (as h after seed intake) to 50% mortality (half-life; <i>t</i>_<i>V</i>50, Eq 5) for four weed seeds passed through the digestive tract of four Holstein cattle groups (horizontal bars denote one standard error).

<p>Time (as h after seed intake) to 50% mortality (half-life; <i>t</i>_<i>V</i>50, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0154057#pone.0154057.e005" target="_blank">Eq 5</a>) for four weed seeds passed through the digestive tract of four Holstein cattle groups (horizontal bars denote one standard error).</p

Total seed recovery (after four days) of four weed seeds fed to different groups of Holstein cattle (vertical bars denote one standard error).

<p>Total seed recovery (after four days) of four weed seeds fed to different groups of Holstein cattle (vertical bars denote one standard error).</p

Total recovered viable seeds (summed over four consecutive days) of the four weed seeds passed through the digestive tract of different groups of Holstein cattle (vertical bars denote one standard error).

<p>Total recovered viable seeds (summed over four consecutive days) of the four weed seeds passed through the digestive tract of different groups of Holstein cattle (vertical bars denote one standard error).</p

Ingredients and chemical composition of the diet of four groups of Holstein cattle.

<p>Ingredients and chemical composition of the diet of four groups of Holstein cattle.</p