Journal of Animal Science

Holzgraefe, D., P.;Jensen, A., H.;Fahey, G., C.;Grummer, R., R.

doi: 10.2527/jas1986.6251145xpmid: 3722007

Abstract Forty-eight second, third and fourth parity crossbred sows were randomly allotted to four dietary treatments: corn:alfalfa-orchardgrass hay (46%; CH); CH plus lasalocid (CHL); corn-soybean meal (CS) or CS plus lasalocid (CSL). Sows were fed these diets through two successive gestations with dietary treatment initiated at 35 d post-coitum and continued until parturition. To equalize daily metabolizable energy intake (6.6 Mcal/sow), 2.64 kg of CH and CHL diets and 1.86 kg of CS and CSL diets were fed. Lasalocid intake was 130 mg · sow−1 · d−1. Sows were weighed and backfat measurements were taken at 35 and 109 d of gestation. Sows also were weighed 14 d postpartum. A 14% crude protein corn-soybean meal diet was fed ad libitum to all sows during lactation and feed intake was recorded. Colostrum samples were obtained within 4 h of farrowing. All live piglets were weighed at birth and 14 d of age. There were no significant differences among dietary treatments in number of live piglets born, piglet birth weight, piglet weight at 14 d of age or sow rebreeding efficiency. Sows fed CHL and CSL diets had more (P<.12) live piglets at 14 d postpartum and lower (P<.03) total fat in colostrum than did CH- and CS-fed sows. Alfalfa-orchardgrass hay feeding resulted in less (P<.04) backfat deposition during gestation, more (P<.04) weight loss from 109 d postcoitum to 14 d postpartum and increased (P<.002) feed consumption during lactation. These results indicate that the corn:alfalfa-orchardgrass hay (46%) diet was essentially equal to the corn-soybean meal diet with regard to sow reproductive performance. Dietary lasalocid reduced fat percentage of sow colostrum. This content is only available as a PDF. Author notes 1 The authors gratefully acknowledge partial financial support of this work by Hoffman-LaRoche, Inc., Nutley, NJ. 2 Present address: Farmland Industries Inc., Kansas City, KS. 3 Dept. of Anim. Sci. 4 Present address: Dept. of Dairy Sci., Univ. of Wisconsin, Madison 53706. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Stokes, K., W.;Shumway, C., R.;Doren, P., E.;Ajayi, W., O.;Nelsen, T., C.;Cartwright, T., C.

doi: 10.2527/jas1986.6251154xpmid: N/A

Abstract Feeder calf classes (sex, age, weight and condition) and cull sales were simulated for cow-calf herds that differed in genotypes for size and milking potential. The Texas A&M Beef Cattle Simulation Model was used to simulate animal performance (growth rates, fertility and herd composition) based on availability, digestibility and crude protein content of Coastal bermudagrass forages typically available in Central Texas. Estimated pricing equations were used to value each animal based on month and year of sale, sex, weight. condition, slaughter steer and grain prices. Revenues, costs and net returns were calculated for 1972 through 1981 for two different resource situations. Results indicated higher net returns to land and management and lower variance were generally associated with increased cow size and decreased milking potential. Net returns to land, livestock, labor and management were highest for large, medium-milking cows, but lower variances were associated with decreased milking potential as well as increased cow size. Although the purpose of the study was to compare the economic viability of the 18 cow types and weaning options. perhaps of equal importance was the finding that not one of them yielded a positive average net return to land and management for the 10-yr period, 1972 through 1981. This content is only available as a PDF. Author notes 2 Present address: Texas Agr. Ext. Serv., 17360 Coit Road, Dallas, TX 75252. 3 Texas Agr. Exp. Sta. 4 Present address: P. O. Box 9206, U.I. Post Office, Ibaden, Nigeria. 5 Present address: USDA-ARS, Fort Keogh LARRS, Miles City, MT 59301. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Denzer, L., E.;Thompson, L., H.;McKeith, F., K.;Parrett, D., F.;Thomas, D., L.

doi: 10.2527/jas1986.6251164xpmid: 3722008

Abstract Two experiments were conducted to evaluate the effect of implants containing zeranol on growth rate, carcass composition, palatability and reproductive organ development of intact male pigs. In Exp. 1, three treatment groups were evaluated: control barrows, intact control boars and implanted boars (implanted at either 28, 56 or 112 d of age with one 12-mg dose of zeranol). In Exp. 2, four treatment groups were evaluated: control barrows, intact control boars, boars implanted at 28 d with 24 mg of zeranol (single implant) and boars implanted at 28 d and re-implanted at 56 and 112 d of age with 24 mg of zeranol (triple implant). Differences for average daily gain and carcass traits were not consistent between treatment groups with the exception of 10th rib fat, where barrows were fatter than boars. There were no differences among treatments due to zeranol for the reproductive organ characteristics, with the exception that bulbourethal gland and teat weights were heavier for boars in Exp. 2. Penis weights and lengths were lower for barrows in both experiments. Juiciness, tenderness, Warner-Bratzler shear force, pork flavor intensity and sensory scores were not consistently affected by male condition or zeranol treatment. In two of the three comparisons, implanted boars had higher off-flavor intensity scores in Exp. 1, but no treatment difference was observed in Exp. 2. Zeranol implantation did not result in significant changes in growth rate, development of reproductive organs or carcass characteristics of young boars. This content is only available as a PDF. Author notes 2 Dept. of Anim. Sci. 4 The authors thank the following people for their assistance in this study: Tom Park, Les Thiel, Dave Weakley and Sharon Laffey. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Grandhi, R., R.;Kornegay, E., T.;Veit, H., P.;Lindemann, M., D.

doi: 10.2527/jas1986.6251172xpmid: 3722009

Abstract The front and hind feet from a total of 64 boars, 86 sows and 107 barrows were radiographed after necropsy to study the nature of inequalities in digits and their relation to nutrition and structural unsoundness in swine. Boars were fed ad libitum or 75% ad libitum with 100 or 150% of 1979 NRC recommended vitamin-mineral levels, whereas, sows were fed the same two levels of energy with 100 or 150% of NRC recommended calcium-phosphorus (Ca-P) levels during the growing-finishing period. Barrows were fed two sources of phosphorus with increasing levels of sodium. Radiographs of metacarpals, metatarsals and associated phalanges were measured for length and deviations of proximal and distal extremities. The length of both medial and lateral bones were longer (P<.05) in boars fed 75% ad libitum than in the ad libitum-fed group. which was probably due to age (285 ± 8.7 vs 240 ± 8.4 d). Dietary energy and Ca-P level did not influence the bone lengths in sows. Similarly, dietary phosphorus source or sodium level had no influence on bone lengths or deviations in barrows. The incidence of inequality in digits with a smaller medial digit was 90.9% in boars, 96.7% in sows and 87.6% in barrows. In boars and sows, the inequality in digits of front feet was due to lower positioning of proximal extremities of lateral bones because the total lengths of both medial and lateral bones were approximately equal. In hind feet, this inequality was more due to longer lateral bones because the proximal extremities of metatarsals were positioned at approximately an equal level. Correlation coefficients between soundness scores and distal deviations of front and hind feet in boars and sows were not significant (P<.05). These results indicate that the inequality in digits of boars, sows and barrows was influenced very little by the nutritional factors examined in this study, and that the inequality of lengths and positions of digits was not a primary cause for structural unsoundness. This content is only available as a PDF. Author notes 2 Present Address: Agriculture Canada Res. Sta., Box 610, Brandon, Manitoba, Canada R7A 5Z7. 3 Dept. of Anim. Sci. 4 Div. of Pathol, and Public Practice. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Stobart, Robert, H.;Russell, William, C.;Larsen, Svend, A.;Johnson, C., L.;Kinnison, Joey, L.

doi: 10.2527/jas1986.6251181xpmid: N/A

Abstract A study was conducted to determine and quantify sources of variation in fiber diameter within a lot of wool. Results showed that on an individual breed basis, 34 to 82% of the lot variance in fiber diameter was derived from within-staple, fiber-to-fiber variance. Similarly, 58 to 92% of individual fleece variance in fiber diameter was traced to the same source. Except for fleeces from two commercial flocks where seasonal nutritional status and apparent breed influences were shown important, variances between body regions, along fibers and between fleeces represented one-third or less of total variation in groups of fleeces. This content is only available as a PDF. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Esbenshade, K., L.;Britt, J., H.;Armstrong, J., D.;Toelle, V., D.;Stanislaw, C., M.

doi: 10.2527/jas1986.6251187xpmid: 3722010

Abstract Weight, heartgirth, backfat and body condition of sows was monitored in a commercial, farrow-to-finish unit during 1 yr. Measurements were obtained during the third, ninth and fifteenth week of gestation and the day after weaning. Litter performance and rebreeding rate also were recorded. Body weight and heartgirth increased (P<.01) over parities because gestational gains were larger than lactational losses. Backfat tended to be lower in later parities. Body weight, heartgirth and backfat, but not condition score, declined from weaning to the third week of the subsequent gestation in both first and second litter sows. Correlations among measures of body condition were low (<.45), except the overall correlation between body weight and heartgirth. Number of pigs born alive increased and interval to estrus decreased in later parities. There were no significant relationships between changes in body condition and rebreeding performance of sows. These results suggest that changes in body condition typically observed in sows housed in commercial production units may be too subtle to have an effect on reproductive performance. This content is only available as a PDF. Author notes 2 This investigation was supported in part by a grant from the Natl. Pork Producers Council, Des Moines, IA, and by USDA Cooperative Agreement No. 7004-20370-010-00S. The authors thank Carla McKinney for secretarial assistance. 3 Dept. of Anim. Sci. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Doren, P., E.;Long, C., R.;Cartwright, T., C.

doi: 10.2527/jas1986.6251194xpmid: 3722011

Abstract Characters related to production and reproduction were observed on 744 straightbred and F2 calves and their dams produced in a five-breed diallel with Angus, Brahman, Hereford, Holstein and Jersey breeds. These data were analyzed to estimate the effects of these characters on the relationship between weaning weight and calving interval. The model used for analysis of postpartum conception and calving interval included breedtype, season of conception, parity and management of the dam as main effects; condition of dam nested within parity: and age, weight and weight change of dam and weaning weight of previous calf as covariates. All effects and covariates were significant sources of variation in conception and calving interval. Brahman cows exhibited the longest conception and calving intervals, whereas Hereford × Jersey F1 cows had the shortest intervals. Heterotic effects for these intervals were low and nonsignificant. Weaning weight of the previous calf was positively correlated with postpartum conception and calving interval, but to determine the magnitude of the relationship the need to adjust for differences in breedtype, condition, parity, early management, age, weight and weight change of the dam was apparent. This content is only available as a PDF. Author notes 1 Present address: Texas Agr. Exp. Sta., Overton, TX 75684. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Caton, J., S.;Jesse, G., W.;Day, B., N.;Ellersieck, M., R.

doi: 10.2527/jas1986.6251203xpmid: 3722012

Abstract In the late fall and winter of 1982 to 1983, 112 crossbred gilts were used in a factorially arranged experiment to determine the effect of confinement on the age at which a gilt reaches first estrus (puberty). Two environments (confinement and nonconfinement) and three ages at movement to non-confinement (100, 140, and 180 d) were studied. No differences were detected (P>.05) between confinement and non-confinement in the proportions of gilts reaching puberty by 210 d of age. Gilts were older at puberty (P<.05) in confinement than in non-confinement (192.0 vs 187.7 d) and had a longer interval (P<.05) from first boar contact to first estrus (12.1 vs 7.8 d). Age at puberty (192.1 vs 187.0 vs 190.5 d) and the porportion reaching puberty (56.4 vs 45.7 vs 65.8%) were not different (P>.05) between age-of-movement groups. However, a higher (P<.05) proportion of the non-confinement gilts reached puberty within 10 d after the beginning of boar exposure than confinement (44.6 vs 26.8%). Moving gilts from confinement to non-confinement (pasture) at 180 d appeared to be the most effective method tested for inducing puberty in gilts. This content is only available as a PDF. Author notes 2 Present address: Dept. of Anim. and Range Sci., New Mexico State Univ., Las Cruces 88003. 3 Dept. of Anim. Sci. 4 Agr. Exp. Sta. Statistician. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Caton, J., S.;Jesse, G., W.;Day, B., N.;Ellersieck, M., R.

doi: 10.2527/jas1986.6251210xpmid: 3722013

Abstract One-hundred crossbred gilts were used in an experiment that was designed to examine the effects of duration of boar exposure on the proportion of gilts reaching first estrus. Two replicates (summer and fall) of 50 gilts each were randomly assigned, within litter, to one of the following treatments: 1) 30 min of daily boar exposure, 2) 15 min of daily boar exposure, 3) 5 min of daily boar exposure, 4) continuous fence-line boar exposure, plus walked to a neutral pen and exposed to a different boar for 10 to 15 min daily, or 5) continuous fence-line boar exposure. Boar exposure lasted for 30 d. The percentage of gilts exhibiting first estrus by 210 d of age ranged from a high of 65.0 for treatment 4 to a low of 10.0 for treatment 5. Treatments 1, 3 and 4 were greater than treatment 5 (P<05), but not different from treatment 2. There were no differences in average age at first estrus. Treatment means for days to puberty after boar exposure were not different (P>.05). However, a significant treatment × season interaction occurred. This interaction appears to suggest seasonal trends. These results indicate that treatments 1 and 4 (30 min daily and continuous fence-line boar exposure plus 10 to 15 min, respectively) were the most effective methods tested for the induction of first estrus. This content is only available as a PDF. Author notes 2 Present address: Dept. of Anim. and Range Sci., New Mexico State Univ., Las Cruces 88003. 3 Dept. of Anim. Sci. 4 Agr. Exp. Sta. Statistician. Copyright 1986 by American Society of Animal Science American Society of Animal Science

Perry, T., W.;Riley, J., G;Mohler, M., T.;Pope, R., V.

doi: 10.2527/jas1986.6251215xpmid: 3522519

Abstract Two 56-d shipping fever trials of similar design were conducted the same season (fall) at Kansas State University (KSU) and at Purdue University (PU) to compare various levels of Chlortetracycline (0 or 350 mg · head−1 · d−1 continuously or 1, 2 or 4 g · head−1 · d−1 for the first 14 d). Weanling crossbred steer calves were utilized (210 head of Angus × Simmental, averaging 197 kg, at KSU; 268 head of Angus × Hereford, averaging 192 kg, at PU). For the first 28 d in the KSU trial (October 13 to December 8), cattle that received 4 g · head−1 · d−1 the first 14 d gained more rapidly (P<.05) than cattle fed 350 mg · head−1 · d−1 continuously or than the controls that received no Chlortetracycline (CTC; 1.05 vs .92 or .93 kg/d, respectively). Cattle that received 4 g CTC · head−1 · d−1 for the first 14 d required less (P<.05) dry matter per kg gain than steers that received 350 mg · head−1 · d−1 continuously over the 56-d period. In the PU trial (October 6 through December 1), all CTC treatments resulted in increased feed efficiency (P<.05) over the controls through 28 d, and the 4 g · head−1 d−1 for 14 d and 350 mg · head−1 · d−1 continuously, improved feed efficiency over the other groups for the 56-d period. Daily gain at 28 d was improved (P<.05) in the PU trial by 350 mg · head−1 · d−1 continuously or 2 or 4 g · head−1 · d−1 for 14 d; at 56 d, 350 mg · head−1 · d−1 continuously or 4 g · head−1 · d−1 for 14 d improved (P<.05) gain. This content is only available as a PDF. Author notes 3 The authors acknowledge the American Cyanamid Co., Princeton, NJ for financial support, chlortetracycline and other materials. 4 Dept. of Anim. Sci., Purdue Univ. 5 Dept. of Anim. Sci. and Ind., Kansas State Univ. Copyright 1986 by American Society of Animal Science American Society of Animal Science