Chlortetracycline

Abstract

This study was conducted to evaluate vitamin E injection and Se in a mineral supplement in late gestation on lamb survival and pre-weaning growth performance. Ewes were grouped in pens based on their fetal count and BW. The feed provided to ewes in late gestation included alfalfa hay, corn, and protein supplement according to NRC (1985) recommendations. Ewes in late gestation were assigned to a 2 × 2 factorial arrangement of treatments within fetal count (single, twin, and triplet + quad). Treatments were no vitamin E or 900 IU of vitamin E injected i.m. per week and 10 or 90 ppm of Se in a mineral supplement fed ad libitum. Within each pen of ewes (8 to 10 head), approximately one-half of the ewes received injectable E beginning 4 wk before the first expected lambing; the other one-half received no vitamin E. Vitamin E treatments ended at lambing time; however, ewes remained on their respective mineral sources during lactation. Lambs were provided access to creep (16% CP, 83% TDN, and fortified with 35,000 IU of vitamin E, 0.27 g of Se, and 50 g of chlortetracycline/909 kg of creep feed) initiated at an average 10 d of age to weaning. Weekly injection of 900 IU of vitamin E did not affect birth BW (BBW) of lambs. However, 90 ppm of Se fed ad libitum improved BBW of lambs (5.06 vs 4.88 kg, P

(Key Words: Sheep, Vitamin E, Selenium, Survival, Growth.)

Introduction

Several nutrients have the duel function of meeting basic physiological needs and developing the immune system, thereby enhancing disease resistance. Vitamin E functions primarily as an antioxidant in cellular membranes (Burton and Ingold, 1989), complimenting the action of the enzyme glutathione peroxidase, which reduces peroxides formed during oxidation. Selenium is an integral component of the glutathione peroxidase enzyme (Rotruck et al., 1973). If vitamin E helps protect membrane integrity of cells, the health status and, subsequently, the efficiency of growth and production should be increased by supplementation of vitamin E in sheep. Earlier work has shown that lambs from ewes supplemented with vitamin E had greater vigor scores and pre-weaning BW gains (Gentry et al., 1992; Williamson et al., 1996). Selenium treatment of sheep in low Se regions resulted in an increase in yearling BW of wether and ewe lambs (Walker et al., 1979), the number of lambs born per ewe (Mudd and Mackie, 1973), and lamb survival to weaning (Kott et al., 1983). Treatment of pregnant ewes with vitamin E and Se resulted in greater BW gain of lambs from birth to 56 d (Horton and Jenkins, 1978). These and many other sheep studies have demonstrated positive growth and immune responses to supplemental vitamin E and Se, yet the vitamin E and Se requirements or optimum levels for supplementation have not been clearly established. The objective of this study, therefore, was to help further evaluate vitamin E injection and Se supplementation in late gestation on lamb birth BW (BBW) and survival and pre-weaning growth performance.

Materials and Methods

Experimental Animals. Whiteface ewes composed of primarily Polypay × Dorset crosses maintained at the McNay Research Farm in south central Iowa in Chariton were used in the 2-yr study. Ewes were divided and bred to either Romanov × Dorset rams or Suffolk and Columbia rams.

Design and Treatments. Ewes in late gestation, beginning 4 wk before the first expected lambing, were assigned to a 2 × 2 factorial arrangement of treatments within fetal count. Treatments were no vitamin E or 900 IU of injectable vitamin E/wk and 10 or 90 ppm of Se in a mineral supplement fed ad libitum. One-half of the 14 and 10 pens of ewes during the 2-yr study, respectively, received 10 ppm Se; the other one-half of the pens of ewes received 90 ppm of Se. Within each pen of ewes (8 to 10 head), approximately one-half of the ewes received injectable vitamin E, and the other one-half received no vitamin E. The commercial vitamin E used in this study was Vital-E(TM)-300 (Stuart Products, Bedford, TX), which contained 300 IU/mL of vitamin E as d-α-tocopherol. Three milliliters of vitamin E were injected s.c. in the neck each week to ewes in late gestation. Selenium was supplemented through two mineral sources: 1) Golden Sun® (Golden Sun Feed, Inc., Estherville, IA) (10 ppm of Se) and 2) Big Gain® (Big Gain, Inc., Mankato, MN) (90 ppm of Se). Vitamin E treatments ended at lambing time; however, ewes remained on their respective mineral sources during the entire lactation.

Animal Management. Ewes were shorn in mid- to late December. After shearing, the ewes were treated with tramisol (Pittman Moore Inc., Washington Crossing, NJ) and ectrin (Boehringer Ingelheim Vetmedica Inc., St. Louis, MO) for internal and external parasites, respectively. The flock was housed indoors in a dirt floor facility. Ewes were grouped in 3.05- × 5.49-m pens with 8 to 10 head per pen. Ewes were scanned with a BCF Oviscan 3® ultrasound scanner (BCF Technology Ltd., Livingston, Scotland) between d 40 and 80 of gestation to determine the number of fetuses to facilitate grouping the ewes. A late gestation diet was provided beginning 4 wk prior to the first expected lambing. Ewes were fed twice daily in fence-line feed bunks. The feeds provided to ewes in late gestation included alfalfa hay, corn, and protein supplement according to NRC (1985) standards. No protein supplement was provided during the second trial.

During the 35-d lambing season, ewes were observed daily at 0600, 0800 through 1700, 1900, and 2300 h for lambing activities. Ewes were provided with assistance when a lamb had not been delivered after 30 min of active labor. After lambing, ewes were penned with their lambs in 1.5- × 1.5-m lambing jugs for 1 to 3 d to ensure bonding between the dam and newborns. If triplets or more were born, only two lambs were allowed to be reared with the dam, and the extra lambs were removed at 12 to 24 h of age and reared artificially. These artificially reared lambs were not included in the analysis for any traits except BBW. All lambs included in the study were provided access to pelleted creep from 10 d of age to weaning. The creep feed contained 16% CP and 83% TDN, 0.84% Ca, 0.38% P, and 0.39 mg/kg of Se. The creep diet was fortified with 35,000 IU of vitamin E, 0.27 g of Se, and 50 g of chlortetracycline/909 kg. Lambs were weaned each year at an average age of 65 d.

Data Collected. Data on BBW of lambs (live or stillborn), type of birth (TB), and sex of lambs were recorded between 12 to 24 h of age. Weaning BW (WW) of lambs were adjusted to a constant age basis (60 d) assuming linear growth of lambs from birth to weaning and were termed adjusted weaning BW (Adj-WW). Survival rates (SR) were calculated as the percentage of lambs weaned per lambs born (live or stillborn) by their dam.

Statistical Analysis. Data regarding BBW, WW, Adj-WW, and ADG were analyzed using GLM procedures (SAS®; SAS Institute Inc., Cary, NC). The data were analyzed by fitting effects of year (2 yr), age of dam (1- to 2-, 3- to 5-, 6- to 7-yr-old), TB (singles, twins, triplets-quads), gender (male, female), vitamin E (0 or 900 IU), Se (10 or 90 ppm), and two-way interactions between age of dam, vitamin E, and Se. Effect of gender was not significant (P>0.10) for traits recorded on lambs to weaning, except BBW; therefore, gender effect was not included in the model for those traits. Effect of sire breed was not significant (P>0.10) for any trait recorded on lambs to weaning; therefore, sire breed effect was not included in any model. Survival rates were analyzed using Chi-square design (Steel and Torrie, 1980). Birth BW and all postnatal traits (WW, Adj-WW, ADG, and SR) up to weaning were analyzed on an individual lamb basis. The models used in the analyses of traits for individual lamb data are presented in Table 1.

Results and Discussion

Year effects were significant for BBW, WW, Adj-WW, and ADG of lambs as summarized in Table 2. In yr 2, lambs were heavier (P

Single-birth lambs were heavier in BBW and WW (P

All multiple-birth lamb classifications had different ADG (P

Vitamin E given via s.c. injection (900 IU/wk) to ewes during late gestation had no significant effect on BBW; however, the pre-weaning performance (WW, Adj-WW, and ADG) was improved (P

Selenium supplementation of 90 ppm to ewes during late gestation showed marginal improvement of BBW (P

The interactions between vitamin E and Se were nonsignificant for BBW, WW, Adj-WW, and ADG (Table 1).

Age of dam had a quadratic effect (Table 1; P=0.001) on BBW of lambs. Birth BW of lambs born to 3- to 5-yr-old ewes were heavier than lambs born to 1- to 2- and 6-to 7-yr-old ewes (Table 4). The effect of age of dam on WW of lambs was significant (Table 1; linear; P= 0.082). Lambs born to 1- through 5-yr-old ewes were heavier at weaning than lambs born to 6- and 7-yr-old ewes. Adjusted weaning BW and ADG of lambs were affected (quadratic; P=0.006, P=0.046, respectively) by age of dam. Lambs born to 1- through 5-yr-old ewes had heavier Adj-WW and grew faster than lambs born to 6- and 7-yr-old ewes (Table 4). Our results for BBW are in agreement with Wright et al. (1975) and London and Weniger (1995). Wright et al. (1975) found that lambs from 2-yr-old ewes were lighter at birth than lambs from dams of all other ages. London and Weniger (1995) found that BBW increased through the fifth parity in dams in a sub-humid zone (1.89 kg) and through the sixth parity in dams in a humid zone (1.71 kg).

Vitamin E and age of dam had significant quadratic interactions for WW (P=0.021), Adj-WW (P=0.001), and ADG (P=0.001) of lambs (Tables 1 and 5). Pre-weaning performance of lambs born to 3-, 4- and 5-yr-old ewes was not significantly affected by vitamin E; however, ADG of lambs born to 1- and 2-yr-old and 6- and 7-yr-old ewes was enhanced (P

An interaction between Se supplementation and age of dam was significant (linear; P=0.022) for BBW of lambs (Table 1; Figure 1). Birth BW of lambs was improved when 90 ppm of Se were supplemented to 6- to 7-yr-old ewes compared with 1- through 5-yr-old ewes in which there was no improvement in BBW because of Se supplementation. The biological explanation for this finding is unclear.

Neither vitamin E injection nor different levels of Se given to ewes had any significant effect on lamb survival regardless of TB for yr 1 (Table 6). However, in yr 2 twin lambs born to ewes that received vitamin E had a greater (P

Different levels of Se supplementation to ewes during late gestation and during lactation had no effect on SR of lambs (Table 6). All lambs, regardless of ewe treatment, were receiving 0.27 g of Se/909 kg of creep feed, and that might have helped to satisfy their physiological needs for Se and resulted in similar SR between treated and untreated groups.

Implications

Selenium supplementation at 90 ppm fed ad libitum in a mineral supplement to ewes during the last month of gestation was helpful in increasing BBW of lambs born to 6to 7-yr-old ewes. Injecting ewes weekly with 900 IU of vitamin E during late gestation increased the postnatal growth performance of lambs from 1- to 2- and 6- to 7-yr-old ewes. Similarly, multiple-birth lambs from ewes treated with vitamin E had increased survival rates through weaning in 1 of 2 yr. These findings indicate that Se supplementation to ewes in late gestation and during lactation, and vitamin E supplementation to ewes in late gestation at levels in this study, may provide some improvement in lamb performance and livability. Future studies should focus on determination of optimum levels of vitamin E and Se to enhance ewe and lamb performance during late pregnancy and the gestation period. Gaining insight to the specific function and roles of vitamin E and Se during these time periods would be most helpful.

Acknowledgments

The authors gratefully acknowledge the assistance of P. J. Berger in the statistical analysis.

1 Journal Paper No. J-18559 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Project No. 2572, and supported by Hatch Act and State of Iowa funds.

Literature Cited

Battagalia, F. C., and G. Meschia. 1981. Foetal and placental metabolisms: Their interrelationship and impact upon maternal metabolism. Proc. Nutr. Soc. 40:99.

Burton, G. W., and K. V. Ingold. 1989. Vitamin E as an in vitro and in vivo antioxidant. Ann. N.Y. Acad. Sci. 570:7.

Demiroren, E., J. N. B. Shrestha, and W. J. Boylan. 1995. Breed and environmental effects on components of ewe productivity in terms of multiple births, artificial rearing and 8-month breeding cycle. Small Rum. Res. 16:239.

Gentry, P. C., T. T. Ross, B. C. Oetting, and K. D. Birch. 1992. Effects of supplemental d-alpha-tocopherol on preweaning lamb performance, serum and colostrum tocopherol levels and immunoglobulin G titers. Sheep Res. J. 8:95.

Horton, G. M. J., and W. L. Jenkins. 1978. Heamotological and blood chemistry changes in ewes and lambs following supplementation with vitamin E and selenium. Br. J. Nutr. 40:193.

Kollar, L. D., G. A. Whitbeck, and P. J. South. 1984. Transplacental transfer and colostral concentrations of selenium in beef cattle. Am. J. Vet. Res. 45:2507.

Kott, R. W., J. L. Ruttle, and G. M. Southward. 1983. Effects of vitamin E and selenium injections on reproduction and preweaning lamb survival in ewes consuming diets marginally deficient in selenium. J. Anim. Sci. 57:553.

Kott, R. W., V. M. Thomas, P. G. Hatfield, T. Evans, and K. C. Davis. 1998. Effects of dietary vitamin E supplementation during late pregnancy on lamb mortality and ewe productivity. J. Am. Vet. Med. Assoc. 212:997.

London, J. C., and J. H. Weniger. 1995. Investigations into traditionally managed Djallonke-sheep production in the humid and subhumid zones of Asante, Ghana. III. Relationship between birth weight, preweaning growth, and postweaning growth of lambs. J. Anim. Breed. Gen. 112:431.

Meneses, A., T. R. Batra, and M. Hidiroglou. 1994. Vitamin E and selenium in milk of ewes. Can. J. Anim. Sci. 74:567.

Mudd, A. J., and I. L. Mackie. 1973. The influence of vitamin E and selenium on ewe prolificacy. Vet. Rec. 93:197.

NRC. 1985. Nutrient Requirements of Sheep. (6th Rev. Ed.). National Academy Press, Washington, DC.

Njeru, C. A., L. R. McDowell, N. S. Wilkinson, S. B. Linda, and S. N. Williams. 1994. Pre- and postpartum supplemental DL-alpha-tocopheryl acetate effects on placental and mammary vitamin E transfer in sheep. J. Anim. Sci. 72:1636.

Peeters, R., G. Kox, J. Van Isterdael, and J. Van Isterdael. 1996. Environmental and maternal effects on early postnatal growth of lambs of different genotypes. Small Rum. Res. 19:45.

Peeters, R., N. Buys, L. Robijns, D. Vanmontfort, and J. Van Isterdael. 1992. Milk yield and milk composition of Flemish Milksheep, Suffolk and Texel ewes and their crossbreds. Small Rum. Res. 7:279.

Pehrson, B., J. Hakkarainen, and L. Blomgren. 1990. Vitamin E status in newborn lambs with special reference to dl-alpha-tocopheryl acetate supplementation in late gestation. Acta Vet. Scand. 31:359.

Robinson, J. J., I. McDonald, C. Fraser, and R. M. J. Crofts. 1977. Studies on reproduction in prolific ewes. I. Growth of the products of conception. J. Agric. Sci. (Lond.) 88:539.

Rotruck, J. T., A. L. Pope, H. E. Ganther, A. B. Swanson, D. G. Hafeman, and W. G. Hoekstra. 1973. Selenium: Biochemical role as a component of glutathione peroxidase. Science 179:588.

Steel, R. G. D., and J. H. Torrie. 1980. Principles and Procedures of Statistics: A Biometrical Approach. (2nd Ed.). McGraw-Hill Publishing Co., New York.

Walker, S. K., G. H. Hall, D. G. Smith, R. W. Ponzoni, and G. F. Judson. 1979. Effect of selenium supplementation on survival, live weight and wool weight of young sheep on Kangaroo Island, South Australia. Aust. J. Exp. Agric. 19:689.

Williamson, J. K., M. L. Riley, A. N. Taylor, and D. W. Sanson. 1996. Performance of nursing lambs receiving vitamin E at birth or from dams that received vitamin E. Sheep Goat Res. J. 12:69.

Wright, L. A., F. A. Thrift, and R. H. Dutt. 1975. Influence of ewe age on productive characters of Southdown sheep. J. Anim. Sci. 41:517.

A. ALI, D. G. MORRICAL, M. P. HUFFMAN2, PAS, and M. F. AL-ESSA

Department of Animal Science, Iowa State University, Ames 50011

2 To whom correspondence should be addressed: phoffman@iastate.edu

Copyright American Registry of Professional Animal Scientists Dec 2004
Provided by ProQuest Information and Learning Company. All rights Reserved