Influence Of Creep Feeding And Protein Level On Maternal Performance Of Replacement Beef Heifers

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1 Influence Of Creep Feeding And Protein Level On Maternal Performance Of Replacement Beef Heifers Abstract W. J. Sexten, D.B. Faulkner, J. M. Dahlquist Department of Animal Sciences, University of Illinois, Urbana Forty-eight Simmental x Angus heifer calves were utilized to determine the effects of prebreeding diet type and prebreeding diet protein level on the future milk production of replacement heifers. Preweaning treatments were initiated as no creep, a cracked shelled corn creep and a cracked shelled corn creep with 6.6% blood meal and 6.4% feather meal added. After weaning the noncreep-fed heifers consumed a roughage-based diet formulated to meet NRC recommendations for metabolizable protein (MP). The creep-fed calves were limit-fed grain-based diets. Heifers fed the corn creep consumed a postweaning development diet formulated to match MP intake of the noncreep-fed cattle. The postweaning diet of heifers fed the corn creep with blood and feather meal added exceeded MP recommendations by 100g/d. Prebreeding diet type did not influence future reproductive or maternal performance of developing beef heifers. Prebreeding diets formulated to provide an excessive amount of dietary protein did not impact the reproductive or maternal performance of replacement heifer calves. Introduction Providing nursing calves access to supplemental feed, or creep feeding, increases average daily gain of calves on pasture (Tarr et al., 1994; Buskirk et al., 1996a). Improved preweaning gains results in heavier weaning weights and greater potential return for producers who market calves at weaning. However, creep feeding negatively impacts replacement heifers by depressing future milk production, calf weaning weights and lifetime productivity (Holloway and Totusek 1973b; Martin et al., 1981). The prepubertal mammary growth phase is a critical period in mammary development that starts as early as 3 months of age and lasts until puberty (Sinha and Tucker 1969; Sejrsen 1978). Due to the overlap of the prepubertal mammary growth phase and the preweaning period producers retaining replacement heifers must decide between maximizing future milk production and increasing weaning weights. Several management strategies have been suggested to overcome the effects of creep feeding. Sorting replacement heifers prior to weaning is one alternative however this practice requires selection early in development. Maintenance of male and female summer pasture groups is another option, yet this requires cattle handling and raises both pasture and bull requirements. A creep feeding strategy designed to enhance weaning weights while preventing milk suppression would be desirable. Dairy heifers have demonstrated a response to changes in diet composition during the prepubertal period. Heifers developed on a 22% CP diet gained 0.97 kg/d without negatively impacting milk production (Capuco et al., 1995). Radcliff et al., (1997) indicated high protein high energy diets have the potential to permit ad libitum consumption without negatively impacting mammary gland development.

2 Sexten et al., Materials and Methods The objectives of this experiment were to evaluate the effects prebreeding diet type and to evaluate diet protein level on the future milk production of replacement beef heifer calves. We hypothesized that grain-based prebreeding diets would negatively impact future milk production of replacement heifers, however, the addition of a highly undegraded protein source to the grainbased diet would alleviate the negative impacts of accelerated prepubertal gains on milk production. To test this hypothesis 48 Simmental x Angus crossbred cows nursing heifer calves from the Orr Beef Research Center, in Baylis, IL were assigned to either a forage-based development diet, a grain-based development diet or a grain-based development diet excessive in dietary protein on July 7, All treatments nursed dams and grazed mixed pastures of endophyte infected tall fescue (Festuca arundinacea), orchardgrass (Dactylis glomerata), white clover (Trifolium repens), and alfalfa (Medicago sativa) from July 7, 1998 until weaning on September 15, During the preweaning period the forage-based heifers received no supplemental feed. After weaning forage heifers were given ad libitum access to a forage-based diet (Tables 2 and 3) formulated to meet NRC (1996) recommendations for metabolizable protein (MP). The grain-based treatment was offered a cracked corn creep (Table 1) while nursing dams and after weaning were limit-fed a grain based diet (Tables 2 and 3) at 1.8% of BW formulated to match MP intake of the forage heifers. During the preweaning period, heifers on the grain-based development diet with excess dietary protein were offered a cracked shelled corn creep with 6.6% blood meal and 6.4% feather meal (Table 1) added. After weaning heifers were limit-fed a grain-based diet (Tables 2 and 3) at 1.8% of BW formulated to exceed MP requirements by 100 g/d. All postweaning treatments were administered in drylot pens. Treatment diets ended on March 26, 1999 and heifers were fed 9.2 kg/(hd d) of 70% ground alfalfa hay and 30% ground corn diet until summer turnout on April 20, All experimental procedures followed those approved by University of Illinois Laboratory Animal Care Advisory Committee. Cows were weighed and assigned a body condition score at the start and end of the grazing season. Calves were weighed full and hip heights measured at trial initiation and completion. To synchronize estrus heifers were administered an intravaginal progesterone insert (CIDR) on April 1, Seven days later CIDRs were removed and heifers were injected with 25mg of PGF 2. Estrus detection commenced the day following CIDR removal and heifers were bred according to the AM/PM rule. On the third day of estrus detection all heifers that had not previously been artificially inseminated were bred (April 11, 1999). Heifers were pasture exposed to an Angus bull from May 6 through June 7, Heifers were maintained on mixed pastures throughout summer and fall. Heifers were rectally palpated for pregnancy on August 3, Prior to calving bred heifers were fed a 50% ground alfalfa, 30% ground corn, 20% soyhull diet at 10.9 kg/(hd d). After calving cows were fed 12.7 kg/(hd d) of 50:50 mix of ground alfalfa and ground corn. Milk production estimates were taken using a twelve-hour weigh-suckle-weigh technique when cows were 65.5 ± 2.4 days postpartum. Calves were separated from cows at 1400 and penned in groups of no more than eight to facilitate timely empty and full weight determination. Calves were allowed to suckle dams at 2000 to empty mammary gland. Cows remained in their original pens and were given access to

3 Sexten et al., feed and water as discussed above, calves did not have access to feed or water after At 800 the following day, calves were weighed empty and permitted to nurse dams for 15 minutes in open lots. Cattle were monitored to prevent cross-fostering. Following nursing, calves were reweighed and differences between full and empty weights were considered 12-hour milk production. Daily milk production was calculated by multiplying 12-h production by 2. Calves were early weaned from dams at 98.5 ± 2.4 days postpartum. Statistical significance was considered at an alpha of Performance data were analyzed using the MIXED procedure of SAS (SAS 1999; Littell et al., 1996). Animal served as the experimental unit for maternal performance analysis. Due to lack of pen replication statistical analysis was only conducted on postcalving performance. Means were separated using orthogonal contrasts to compare forge versus grain based development diets, and grain versus grain plus protein development diets. Reproductive data were analyzed using the GENMOD procedure of SAS (1999). The full model included prebreeding dietary treatment, AI bull and associated interactions as fixed effects. Animal was the experimental unit. The data followed a binomial distribution with zero representing failure to breed and one equaling reproductive success. Results and Discussion Mean heifer performance prior to breeding is presented in Table 4. Due to experimental design discussion of results will be limited to reproductive and maternal performance. Creep feeding does not influence ovarian size, uterine horn diameter or the number of follicles at seven months of age (Prichard et al., 1989) however it is well documented that increased preweaning nutrition hastens the onset of puberty (Patterson et al., 1992). As days exposed to creep feed increased from zero to 84, the percentage of heifers pubertal before breeding increased linearly, however pregnancy rates at 19 months of age were not improved by increased time on creep feed (Buskirk et al., 1996a). Similarly, pregnancy, calving and weaning rates were not influenced by diet type or additional protein (Table 5). However, reproductive responses should be viewed with caution, as the number of available experimental units does not allow for robust statistical analysis. The two calves lost between calving and weaning were dead at birth. No differences in pregnancy rates due to creep feeding have been reported in previous reports (Martin et al., 1981; Buskirk et al., 1996b). Additionally, Holloway and Totusek (1973b) reported no differences in weaning rates between creep and noncreep-fed heifers. Providing additional protein during development to dairy replacement heifers in a 75% grain, 25% haylage diet did not impact conception or calving rates compared to a 90% haylage, 10% grain diet (Radcliff et al., 2000). Birth weight and calving ease were not affected by increased prebreeding nutrition or by providing additional dietary protein during the development period (Table 6). The influence of enhanced preweaning nutrition on calving difficulty and calf birth weight is highly variable. Creep feeding has increased (Buskirk et al., 1996a), decreased (Martin et al., 1981) and not affected (Hixon et al., 1982; Buskirk et al., 1996b) calf birth weight. Variable birth weight responses to creep feeding may be attributed to differences in postweaning management as

4 Sexten et al., numerous genetic and environmental factors affect calf birth weight (Holland and Odde 1992). Radcliff et al., (2000) also reported no differences in calf birth weight or calving ease due to additional protein during development. Neither diet type nor additional protein influenced dam size (Table 6). At 66 days postpartum no differences in cow weight or hip height due to prebreeding treatments. Heifers had achieved in excess of 90% of mature weight (590 kg) by 26 months of age. Previous reports also report no differences in postcalving weight or hip height in creep-fed heifers (Holloway and Totusek 1973a; Buskirk et al, 1996a) and no differences in postcalving weight in dairy heifers due to excessive protein during development (Radcliff et al., 2000). Contrary to our hypothesis feeding grain-based prebreeding diets designed to increase ADG by developing replacement heifer calves did not impair future milk production (Table 6). The critical period for mammary development occurs between three months of age and puberty (Sinha and Tucker 1969) this coincides with the preweaning and early postweaning periods. Creep feeding during the preweaning period improved ADG from 0.29 to 0.37 kg/d and depressed subsequent milk production in Angus and Hereford heifers (Hixon et al., 1982). Buskirk et al., (1996a) also reported a linear reduction in milk production as time on creep feed increased from 0 to 84 days and preweaning ADG increased from 0.58 to 0.91 kg/d. In this experiment prebreeding ADG was sufficient to depress milk production in grain-based diets, additionally there were sufficient observations to detect milk production differences. Lack of differences due to prebreeding diet type may be due in part to milk quantification procedures. Belcher et al., (1980) reported calves nursing cows during peak lactation may not consume all the dam s milk during a weigh-suckle-weigh procedure. In this experiment milk production exceeded 8 kg/d, while Belcher et al., (1980) reported milk production estimates of 7.6 kg/d. Addition of excess dietary protein during development did not influence milk production of replacement heifer calves (Table 6). Protein to energy ratio is responsible for 61% of the variation in mammary response to rapid growth in dairy heifers gaining in excess of 0.9 kg/d during the prepubertal period (Vandehaar 1997). Providing additional protein during the prepubertal period did not influence heifers on a moderate growth rate (Waldo et al., 1998). Milk production was not enhanced by additional prepubertal protein when ADG exceeded 1.1 kg/d (Radcliff et al., 2000). Whitlock et al., (2002) concluded that dietary protein does not effect mammary development of prepubertal heifers gaining rapidly so long as the diet contains adequate protein for normal growth. Therefore providing cracked shelled corn to replacement heifer calves nursing dams and grazing pasture supplied adequate protein in this experiment. Calf ADG and weaning weight were not influenced by dams prebreeding treatment (Table 6). Calf performance was not expected to differ, as milk production was not different among treatments. Creep feeding Angus heifers reduced lifetime calf production by 89 kg (Martin et al., 1981). In many reports where creep feeding impaired milk production (Hixon et al., 1982; Buskirk et al., 1996a,b) calf ADG and weaning weight were not influenced by the lower milk production of creep-fed dams.

5 Sexten et al., Implications Providing a grain-based prebreeding diet to developing heifers did not influence future reproductive or maternal performance. Prebreeding development diets containing an excessive amount of dietary protein did not impact the reproductive or maternal performance of replacement heifer calves. Literature Cited Belcher, C. G., R. R. Frahm, D. R. Belcher and E. N. Bennett Comparison of machine milkout and calf nursing techniques for estimating milk yields of various two-breed cross range cows. Ok. Agric. Exp. Sta. Res. Rep. MP-107:6-10. Buskirk, D. D., D. B. Faulkner, and F. A. Ireland. 1996a. Subsequent productivity of beef heifers that received creep feed for 0, 28, 56, or 84 d before weaning. Prof. Anim. Sci. 12: Buskirk, D. D., D. B. Faulkner, W. L. Hurley, D. J. Kesler, F. A. Ireland, T. G. Nash, J. C. Castree and J. L. Vicini. 1996b. Growth, reproductive performance, mammary development, and milk production of beef heifers as influenced by prepubertal dietary energy and administration of bovine somatotropin. J. Anim. Sci. 74: Capuco, A. V., J. J. Smith, D. R. Waldo, and C. E. Rexroad, Jr Influence of prepubertal dietary regimen on mammary growth of Holstein heifers. J. Dairy Sci. 78: Hixon, D. L., G. C. Fahey, D. J. Kesler and A. L. Neumann Effects of creep feeding and monensin on reproductive performance and lactation of beef heifers. J. Anim. Sci. 55: Holland, M. D. and K. G. Odde Factors affecting calf birth weight: A review. Theriogenology. 38: Holloway, J. W. and R. Totusek. 1973a. Relationship between preweaning nutritional management and the growth and development of Angus and Hereford females. J. Anim. Sci. 37: Holloway, J. W. and R. Totusek. 1973b. Relationship between preweaning nutritional management and subsequent performance of Angus and Hereford females through three calf crops. J. Anim. Sci. 37: Littell, R. C., G. A. Milliken, W. W. Stroup and R. D. Wolfinger SAS system for mixed models. SAS Inst. Inc., Cary, NC. Martin, T. G., R. P. Lemenager, G. Srinivasan and R. Alenda Creep feed as a factor influencing performance of cows and calves. J. Anim. Sci. 53:33-39.

6 Sexten et al., NRC Nutrient requirements of beef cattle (7 th Ed). National Academy Press, Washington DC. Patterson, D. J., R. C. Perry, G. H. Kiracofe, R. A. Bellows, R. B. Staigmiller, and L. H. Corah Management considerations in heifer development and puberty. J. Anim. Sci. 70: Prichard, D. L., T. T. Marshall, D. D. Hargrove, and T. A. Olson Effects of creep feeding, zeranol implants and breed type on beef production: II. Reproductive development and fat deposition in heifers. J. Anim. Sci. 67: Radcliff, R. P., M. J. Vandehaar, A. L. Skidmore, L. T. Chapin, B. R. Radke, J. W. Lloyd, E. P. Stanisiewski, and H. A. Tucker Effects of diet and bovine somatotripin on heifer growth and mammary development. J. Dairy Sci. 80: Radcliff, R. P., M. J. Vandehaar, L. T. Chapin, T. E. Pilbeam, D. K. Beede, E. P. Stanisiewski and H. A. Tucker Effects of diet and injection of bovine somatotropin on prepubertal growth and first-lactation milk yields of Holstein cows. J. Dairy Sci. 83: SAS SAS/STAT User s Guide (Version 8, 1 st Ed.). SAS Inst. Inc., Cary NC. Sejrsen, K Mammary development and milk yield in relation to growth rate in dairy and dual purpose heifers. Acta Agric. Scand. 28: Sinha, Y. N., and H. A. Tucker Mammary development and pituitary prolactin level of heifers from birth through puberty and during the estrous cycle. J. Dairy Sci. 52: Tarr, S. L., D. B. Faulkner, D. D. Buskirk, F. A. Ireland, D. F. Parrett and L. L. Berger The value of creep feeding during the last 84, 56, or 28 days prior to weaning on growth performance or nursing calves grazing endophyte-infected fescue. J. Anim. Sci. 72: VandeHaar, M. J Dietary protein and mammary deveopment of heifers: analysis from literature data. J. Dairy Sci. 80:(Suppl. 1):216 (Abstr.). Waldo, D. R., A. V. Capuco and C. E. Rexroad, Jr Milk production of Holstein heifers fed either alfalfa or corn silage diets at two rates of gain. J. Dairy Sci. 81: Whitlock, B. K., M. J. VandeHaar, L. F. P. Silva and H. A. Tucker Effect of dietary protein on prepubertal mammary development in rapidly growing dairy heifers. J. Dairy Sci. 85:

7 Sexten et al., Table 1. Creep diet composition, % DMB Ingredient CORN BFM Cracked corn Blood meal Feather meal Table 2. Postweaning diets from weaning through Dec 25, 1998, % DMB Ingredient NC CORN BFM Ground alfalfa hay Cracked corn Blood meal Feather meal Mineral mix Table 3. Postweaning diets from Dec 26, 1998 through AI, % DMB Ingredient NC CORN BFM Ground alfalfa hay Cracked corn Blood meal Feather meal Mineral mix

8 Sexten et al., Table 4. Performance of heifer calves until breeding a Treatment b Item NC CORN BFM Initial weight, kg Weaning weight, kg Preweaning ADG, kg/d Creep dry matter intake, kg/d Supplemental gain:feed Weaning hip height, cm Prebreeding weight, kg Postweaning ADG c, kg/d Breeding weight, kg Breeding BCS d a Arithmetic means b NC = no creep, CORN = cracked corn creep, BFM = cracked corn with blood and feather meal c Postweaning ADG includes 185 d feeding period from weaning through prebreeding weights d BCS = body condition score where 1 = emaciated and 9 = obese

9 Sexten et al., Table 5. Effect of nutritional management during the development period on replacement heifer reproductive performance Treatment a P = P = Item NC CORN BFM NC vs CORN and BFM CORN vs BFM n = Pregnancy rate, % Calving rate, % Weaning rate, % a NC = no creep, CORN = cracked corn creep, BFM = cracked corn with blood and feather meal

10 Sexten et al., Table 6. Effect of nutritional management during the development period on maternal performance of replacement heifers a Treatment b P = P = Item NC CORN BFM SEM c NC vs CORN CORN vs and BFM BFM Calf Birth wt, kg Weaning wt, kg d ADG, kg/d e Dam Calving ease f Weight, kg g Hip height, cm g Milk, kg/d g a Least squared means b NC = no creep, CORN = cracked corn creep, BFM = cracked corn with blood and feather meal c Greatest standard error of treatment (SEM) means reported d Early weaning weight at 97.1 ± 2.4 days of age Calf birth to weaning ADG f Calving ease where 1 = no assistance and 4 = Caesarean section g Estimates taken at 65.5 days postpartum 09/03