Management and economics of group-fed dairy calves and dairy steers in an organic production system

Abstract

The objective of this study was to evaluate the effect of early life feeding duration on calf growth, health, and economics of organic dairy calves fed once per day. Heifer calves born during the spring of 2011 (n = 67) and the spring of 2012 (n = 57) were used to evaluate the effect of weaning age, growth, and profitability of group-fed calves in an organic dairy production system. Calves were assigned to replicate feeding groups of ten in super hutches by birth order, and were born at the University of Minnesota West Central Research and Outreach Center, Morris organic dairy. Breed groups were Holsteins (n = 15) selected for high production (HO), Holsteins (n = 23) maintained at 1964 breed average level (H64), crossbreds (n = 54) including combinations of HO, Montbéliarde, and Swedish Red (HMS), and crossbreds (n = 32) including combinations of HO, Jersey, and Swedish Red (HJS). Groups of calves were weaned at 30 (EW), 60 (MW), or 90 (LW) d of age, and groups were fed 1.5% of birth weight of 13% total solids organic whole milk once daily and weaned when the group of ten calves consumed an average of 0.91 kg starter/calf/day for four consecutive days. Body measurements were recorded at birth, weekly during the pre-weaning period, at weaning, and monthly thereafter, and profitability was estimated as a function of the total cost for organic milk and grain for weaning groups to weaning and to the first 90 days of age. Pre-weaning group performance was weaning age (d), EW (47.6), MW (64.5), LW (93.7); gain per day (kg), EW (0.51), MW (0.63), LW (0.75); and weaning weight (kg), EW (61.8), MW (79.2), LW (108.1). There were no significant differences in body weight (kg) for weaning groups at 90 days of age; however, MW calves had significantly lower 120-d body weight (kg) than LW calves, but EW calves did not differ from either MW or LW calves for 120-d body weight. Total feed costs to weaning were $1,092.97 for EW, $1,871.24 for MW, $2,956.64 for LW groups of calves; however, the cost per kg of gain was significantly higher for the EW ($5.54) group than the MW ($4.60) or LW ($4.14) groups during the pre-weaning period. Total costs and cost per kg of gain for the first 90-d of age were lowest for EW and highest for LW. Bull calves (n = 49) were used to compare growth measurements of conventional and organic dairy steers. Calves were assigned to one of three groups at birth; conventional (CONV, n = 16), organic (pasture and concentrate, ORG, n = 16), and organic-grass only (GRASS, n = 17), and were born at the University of Minnesota West Central Research and Outreach Center, Morris from March to May 2011. Breed groups of calves were: Holstein (n = 9), Holsteins (n = 11) maintained at 1964 breed average level, crossbreds (n = 19) that included combinations of Holstein, Montbéliarde, and Swedish Red (HMS), and crossbreds (n = 10) that included combinations of HO, Jersey, Swedish Red, and Normande (HJSN). The CONV steers were fed a diet of 80% concentrate and 20% roughage. The ORG steers were fed a diet of organic corn, organic corn silage, and at least 30% of their diet consisted of organic pasture during the grazing season. The GRASS steers grazed pasture during the grazing season and were fed high quality hay or hay silage during the non-grazing season. Feed intakes were recorded daily with herd management software. A profit function was defined to include revenues and expenses for beef value, feed intake, pasture intake, health cost, and yardage. The GRASS (358.6 kg) steers had significantly lower gain from birth to slaughter than ORG (429.6 kg) and CONV (534.5 kg) steers. Furthermore, the GRASS (0.61 kg/d) steers had significantly lower average daily gain compared to ORG (0.81 kg/d) and CONV (1.1 kg/d) steers. Both organic steer groups had significantly smaller ribeye area (49.5 cm2, 65.8 cm2, respectively) compared to CONV (75.4 cm2) steers. For profitability, GRASS steers had 25% greater profit per steer, than CONV steers. On the other hand, ORG steers had 169% less profit per steer than CONV steers. The higher cost of production for the ORG steers is due to the extreme high value of organic corn. The results of the current study suggest there may be a potential market for the male offspring of organic dairy cattle in the Midwest.</DISS_para> <DISS_para>Holstein and crossbred dairy steers were evaluated for fatty acid profiles, meat quality, sensory attributes, and consumer acceptance of organic dairy-beef compared to conventional dairy-beef. Calves (n=49) were randomly assigned to one of three replicated groups (conventional (CONV), organic (ORG, pasture + concentrates), and grass-fed organic (GRASS)) and were born at the University of Minnesota West Central Research and Outreach Center, Morris, Minnesota from March to May 2011. The CONV steers (n = 16) were fed a diet that contained 80% concentrate and 20% roughage, and ORG steers (n = 16) were fed a diet of organic corn, organic corn silage, and organic protein supplement. Furthermore, ORG steers consumed at least 30% of diet dry matter in high-quality organic pasture during the grazing season. The GRASS steers (n = 17) consumed 100% forage from pasture during the grazing season and high-quality hay or hay silage during the non-grazing season. The ORG (46.9%) steers had fat that was significantly higher in oleic acid (C18:1) than the GRASS (35.7%) and CONV (37.8%) steers. The GRASS steers (22.9%, 1.3%) were significantly lower for monounsaturated and polyunsaturated fat than the ORG (42.9, 2.4%) and CONV (39.4%, 3.1%) steers, respectively. Furthermore, the GRASS steers were significantly higher for omega-3 fat and significantly lower for omega-6 fat than the ORG and CONV steers. Consequently, the GRASS (1.6%) steers had a significantly lower omega-6 to omega-3 fat ratio than the ORG (10.1%) and CONV (13.8%) steers. For sensory attributes, there were no significant differences for ORG (71.3) and CONV (69.2) steers for overall liking; however, the GRASS (56.3) steers had the lowest overall liking among beef consumers. The ORG (73.3) steers had significantly higher flavor liking than the GRASS (56.8) and CONV (69.2) steers. Conversely, the GRASS (6.3) steers had the highest scores for off-flavor compared to the ORG (3.9) and CONV (4.1) steers. The results of the current study suggest there may be a potential market for organic grass-fed dairy steers in the United States.