Journal of Animal Science

Wolter, B. F.;Ellis, M.;Corrigan, B. P.;DeDecker, J. M.

2002 Journal of Animal Science

doi: 10.2527/2002.802301xpmid: 11881919

Abstract The effects of piglet birth weight and liquid milk replacer supplementation of piglets during lactation on growth performance to slaughter weight was evaluated in a study carried out with 32 sows (PIC C-22) and their piglets (n = 384; progeny of PIC Line 337 sires). A randomized block design with a 2 x 2 factorial arrangement of treatments was used. Treatments were birth weight (Heavy vs Light) and liquid milk replacer (Supplemented vs Unsupplemented). The study was divided into two periods. At the start of period 1 (birth to weaning), pigs were assigned to either Heavy or Light (1.8 [SD = 0.09] vs 1.3 kg [SD = 0.07] BW, respectively, P < 0.001) litters of 12 pigs and half of the litters were given ad libitum access to supplemental milk replacer from d 3 of lactation to weaning (21 +/- 0.2 d). In period 2 (weaning to 110 kg BW), a total of 308 pigs were randomly selected from within previous treatment and sex subclasses and placed in pens of four pigs. Pigs were given ad libitum access to diets that met or exceeded nutrient requirements. Pigs in heavy litters were heavier at weaning (6.6 vs 5.7 kg BW; SE = 0.14; P < 0.001) and tended to have more pigs weaned (11.4 vs 10.9 pigs/litter; SE = 0.21; P = 0.10). After weaning, pigs in the Heavy litter had greater ADG (851 vs 796 g; SE = 6.7; P < 0.001) and ADFI (1,866 vs 1,783 g; SE = 17.6; P < 0.001), similar gain:feed (0.46 vs 0.45; SE = 0.003; P > 0.05), and required seven fewer days (P < 0.001) to reach slaughter weight compared to pigs in the Light treatment. Feeding supplemental milk replacer during lactation produced heavier pigs at weaning (6.6 vs 5.7 kg BW; SE = 0.14; P < 0.001) and tended to increase the number of pigs weaned (11.4 vs 10.9 pigs/litter; SE = 0.21; P = 0.10) but had no effect (P > 0.05) on growth performance from weaning to slaughter. However, pigs fed milk replacer required three fewer days (P < 0.01) to reach 110 kg BW. Sow feed intake and BW loss during lactation were not affected (P > 0.05) by either birth weight or milk replacer treatment. In conclusion, birth weight has a substantially greater impact on pig growth performance after weaning than increasing nutrient intake during lactation. Copyright © 2002 by American Society of Animal Science

Brumm, M. C.;Baysinger, A. K.;Wills, R. W.;Thaler, R. C.

2002 Journal of Animal Science

doi: 10.2527/2002.802309xpmid: 11881920

Abstract In each of three trials, 240 crossbred barrows weaned at 17 d of age (5.1 kg BW) were assigned to one of three experimental treatments based on light and heavy weight outcome groups. Experimental treatments were 1) wean-to-finish at 0.69 m2/pig and 15 pigs/pen; 2) wean-to-finish double-stocked at 0.35 m2/pig, 30 pigs per pen for 8 wk and then randomly split into two pens (either stayed in same pen or moved to new pen) for growth to slaughter at 0.69 m2/pig; and 3) nursery facility for 8 wk at 0.35 m2/pig and 15 pigs/pen followed by move to the same grow-finish facility housing wean-to-finish and double-stocked pigs and maintaining pen integrity. Beginning at 38 kg BW, diets were supplemented with either bacitracin methylenedisalicylate at 33 mg/kg to slaughter or tylosin at 44 mg/kg to 59 kg BW and 22 mg/kg thereafter. There were no trial x treatment interactions, even though there was considerable variation in health status among trials. At the end of the 56-d nursery period, wean-to-finish pigs weighed more than nursery (28.7 vs 27.7 kg; P = 0.071) and double-stocked pigs (28.7 vs 26.9 kg; P = 0.002), due to greater ADG (wean-to-finish vs nursery; P = 0.062; wean-to-finish vs double-stocked; P = 0.002) and greater ADFI (wean-to-finish vs nursery; P = 0.024; wean-to-finish vs double-stocked, P = 0.002). There was no effect of treatments (P > 0.1) on ADG, feed conversion, carcass lean percentage, or lean gain during the growing-finishing period. There was also no effect of treatment (P > 0.1) on ADG or ADFI from weaning to slaughter. There was no difference (P > 0.1) between bacitracin methylenedisalicylate and tylosin for ADG, feed conversion, carcass lean percentage, or daily lean gain. These data suggest that housing 5-kg weaned pigs in fully slatted growing-finishing facilities from weaning to slaughter was not detrimental to overall performance. In this experiment, dietary additions of bacitracin methylenedisalicylate or tylosin from 38 kg BW to slaughter weight resulted in similar growth performance. Copyright © 2002 by American Society of Animal Science

Lee, C.;Pollak, E. J.

2002 Journal of Animal Science

doi: 10.2527/2002.802316xpmid: 11881921

Abstract Korean cattle have an unusually short suckling period (4 mo) due to poor milking ability, and this is a hindrance to growth of calves. Therefore, Korean cattle breeders have shown interest in genetic improvement of milking ability. In this study, body weight (birth weight, weaning weight, and yearling weight) and five daily milk yields by period in Korean cattle (Hanwoo) were analyzed using a two-trait sire and maternal grandsire mixed model. The milk yields used were actually measured at sequential intervals from 1 to 4 mo after calving. Posterior means of the parameters were estimated using Gibbs sampling. Heritability estimates (0.25 to 0.26) for daily milk yield at weaning were larger than those with other periods. Genetic impact on daily milk yield, especially at weaning, was emphasized in order to lengthen the suckling period of Korean cattle. Genetic correlation estimates between BW and daily milk yield were all negative (-0.08 to -0.16 for birth weight, -0.04 to -0.21 for weaning weight, and -0.12 to -0.19 for yearling weight), whereas environmental correlation estimates were all positive (0.20 to 0.39 for birth weight, 0.34 to 0.51 for weaning weight, and 0.30 to 0.45 for yearling weight). The negative estimates of genetic correlation between weight and milk yield implied genetic antagonism between direct and maternal effects for weaning weight of beef cattle. Copyright © 2002 by American Society of Animal Science

van der Waaij, E. H.;Bijma, P.;Bishop, S. C.;van Arendonk, J. A. M.

2002 Journal of Animal Science

doi: 10.2527/2002.802322xpmid: 11883428

Abstract Animals will show reduced production when exposed to a constant infection pressure unless they are fully resistant, the size of the reduction depending on the degree of resistance and the severity of infection. In this article, the use of QTL for disease resistance for improving productivity under constant infection pressure is investigated using stochastic simulation. A previously published model was used with two thresholds for resistance: a threshold below which production is not possible and a threshold above which production is not affected by the infection. Between thresholds, observed production under constant infection is a multiplicative function of underlying potential production and level of resistance. Some simplifications of reality were adopted in the model, such as no genetic correlation between potential production and resistance, the absence of influence of lack of resistance on reproductive capacity, and the availability of phenotypes in both sexes. Marker-assisted selection was incorporated by assuming a proportion of the genetic variance to be explained by the QTL, which thus is defined as a continuous trait. Phenotypes were available for production, not for resistance. The infection pressure may vary across time. Results were compared to mass selection on production under constant as well as intermittent infection pressure, where the infection pressure varied between but not within years. Selection started in a population with a very poor level of resistance. Incorporation of QTL information is valuable (i.e., the increase in observed production relative to mass selection) when a large proportion of the additive genetic variance is explained by the QTL (50% genetic variance explained) and when the heritability for resistance is low (h2R = 0.1). Under constant infection pressure, incorporating QTL information does not increase selection responses in observed production when the QTL effect explains less than 25% of the genetic variance. Under intermittent selection pressure, the use of QTL information gives a slightly greater increase in observed production in early generations, relative to mass selection on observed production, but still only when the QTL effect is large or the heritability for resistance is low. The additional advantage of incorporating QTL information is that use of (preventive) medical treatment is possible, or animals may be evaluated in uninfected environments. Copyright © 2002 by American Society of Animal Science

Lee, D. H.;Bertrand, J. K.

2002 Journal of Animal Science

doi: 10.2527/2002.802330xpmid: 11881922

Abstract The importance of genotype × country interactions for weaning and birth weight and postweaning gain between Argentina (AR), Canada (CA), Uruguay (UY), and the United States (US) for populations of Hereford cattle was investigated. Three sample data sets of computationally manageable sizes were formed for each trait and pairwise combination of countries to investigate possible interactions. Parameters were estimated for each sample data set via an accelerated EM-REML algorithm and multiple-trait animal models that considered either weaning or birth weight as a different trait in each country. Direct and maternal (in parentheses) weaning weight genetic correlation estimates for AR-CA, AR-UY, AR-US, CA-UY, CA-US, and UY-US were 0.82 (0.80), 0.81 (0.72), 0.81 (0.79), 0.83 (0.78), 0.85 (0.82), and 0.86 (0.81), respectively. Direct and maternal (in parentheses) birth weight genetic correlation estimates were 0.92 (0.62), 0.97, (0.85), and 0.99 (0.97) for AR-CA, AR-US, and CA-US, respectively. Birth weight was not analyzed for UY due to small amounts of data. Postweaning gain in CA and US was 160-d gain, and in AR and UY 345-d gain was used. Across-country direct genetic correlations for postweaning gain were estimated for each pairwise country data set using a model that considered weaning weight as the same trait across each country, whereas postweaning gain was treated as a different trait in each country. Direct genetic correlation estimates for postweaning gain for AR-CA, AR-UY, AR-US, CA-UY, CA-US, and US-UY were 0.64, 0.80, 0.51, 0.84, 0.92, and 0.83, respectively. The overall results indicate that weaning and birth weights of Hereford calves can be analyzed as the same trait in all countries with a common set of heritabilities and genetic correlations, after adjustment for heterogenous phenotypic variances across countries. Postweaning gain in CA and US can be considered as the same trait and analyzed using a single set of parameters. Postweaning gain in AR and UY should be considered as a separate trait from postweaning gain in CA and US, and postweaning gain in AR and UY can be considered as the same trait and analyzed using a common heritability, after adjustment for phenotypic variance differences between the two countries. Copyright © 2002 by American Society of Animal Science

Scroggs, L. V.;Kattesh, H. G.;Morrow, J. L.;Stalder, K. J.;Dailey, J. W.;Roberts, M. P.;Schneider, J. F.;Saxton, A. M.

2002 Journal of Animal Science

doi: 10.2527/2002.802338xpmid: 11881923

Abstract One hundred twenty 8-wk-old barrows (20.3 +/- 2.0 kg BW) were used to examine the effect of split marketing on selected behavioral, physiological and performance parameters. Pigs were assigned by weight in a randomized complete block design to one of three treatments: SM (split-marketed), six pigs/pen (1.83 m2/pig); C (control), six pigs/pen (1.83 m2/pig); or MC (modified control), three pigs/pen (3.66 m2/pig). The heaviest half of SM animals were removed 1 wk prior to marketing penmates. Control and MC animals remained in their respective groups until marketing. Animals were videotaped during the first 72 h of the study (INITIAL), 72 h prior to (PRE), and following the removal (POST) of pigs in the SM treatment to quantify maintenance behaviors and to identify socially dominant, intermediate, and submissive pigs. A blood sample was collected from each animal upon completion of INITIAL, PRE, and POST time periods to determine neutrophil:lymphocyte ratio and plasma haptoglobin, cortisol, and corticosteroid-binding globulin (CBG) levels. Animals were weighed and feed disappearance was calculated biweekly. Tenth-rib backfat and area of the longissimus muscle at marketing were ultrasonically evaluated on all animals. Regardless of treatment, animals were more (P < 0.01) active (eating, standing/walking, fighting) at INITIAL than at PRE or POST times. Frequency and duration of fights per pen were less (P < 0.01) in MC than in C or SM pigs for all periods observed. Neutrophil:lymphocyte ratio, plasma haptoglobin, and CBG levels were greater (P < 0.01) during the INITIAL period than during the PRE or POST periods but did not differ between treatments. No treatment or time differences were detected in plasma cortisol levels. The MC pigs exhibited greater (P < 0.01) ADFI with poorer feed efficiency compared to C or SM pigs up to split marketing. During the POST period, both MC and SM pigs had greater (P < 0.01) ADFI with poorer (P < 0.01) feed efficiency than C pigs. The ADG was not different among animals as a result of treatment. There were no treatment differences for any of the carcass measurements. Significant differences in performance between the treatment groups could not be attributed to any physiological or behavioral measures reported here. Copyright © 2002 by American Society of Animal Science

Porath, M. L.;Momont, P. A.;DelCurto, T.;Rimbey, N. R.;Tanaka, J. A.;McInnis, M.

2002 Journal of Animal Science

doi: 10.2527/2002.802346xpmid: 11881924

Abstract The objective of this study was to test the combined effect of offstream water and trace mineral salt on cattle distribution in a riparian meadow and its adjacent uplands. From July 15 to August 26, 1996 and 1997, three treatments were each randomly assigned to one pasture in each of three blocks. Sixty cow/calf pairs were then randomly allotted to the grazed pastures. The treatments included 1) stream access and access to offstream water and trace-mineral salt (off-stream), 2) stream access and no access to offstream water or trace-mineral salt (no-offstream), and 3) ungrazed control. The response of cattle was measured through visual observations of cattle distribution, grazing activity and travel distance, cow/calf performance, and fecal deposit distribution. Distribution patterns of the cattle, measured as the distance of cattle from the stream, was characterized by a time of day x treatment x time in grazing period x year interaction (P < 0.05). No-offstream cattle began the day further from the stream than offstream cattle but consistently moved closer to the stream after the morning grazing period (0600 to 0900). Differences in distribution patterns between the two treatments were more pronounced early in the grazing period than late in the grazing period. Grazing activity, fecal deposit distribution, and travel distance of cattle were not affected by the presence of offstream water and trace-mineral salt. Cows and calves with offstream water and trace-mineral salt gained 11.5 kg and 0.14 kg/d more, respectively, than no-offstream cows and calves averaged across years (P < 0.05). Overall, cattle distribution patterns and cow/calf performance were influenced by the presence of offstream water and trace-mineral salt. Changes in distribution were most pronounced early in the grazing season. Copyright © 2002 by American Society of Animal Science

Cozzi, G.;Gottardo, F.;Mattiello, S.;Canali, E.;Scanziani, E.;Verga, M.;Andrighetto, I.

2002 Journal of Animal Science

doi: 10.2527/2002.802357xpmid: 11881925

Abstract Growth performance, forestomach development, and carcass and meat quality of veal calves fed a milk replacer diet (Control) were compared to those obtained from calves fed the same liquid diet plus 250 g x calf(-1) x d(-1) of dried beet pulp or wheat straw. Three groups of 46 Polish Friesian calves, balanced according to initial BW, were assigned to the three dietary treatments in a fattening trial, which lasted 160 d. The provision of either solid feed did not affect the milk replacer intake. However, calves' ADG was increased (P < 0.01) only by feeding the beet pulp diet. The administration of both solid feeds improved calves' health status; calves fed solid feeds required fewer iron treatments for low hemoglobin and needed less medical treatments for respiratory or gastrointestinal diseases. In comparison to the Control calves, the provision of wheat straw and beet pulp increased iron intake throughout the fattening period by 41 and 130%, respectively. However, only calves fed beet pulp showed higher levels of hemoglobin and plasma iron concentrations (P < 0.05), whereas the same blood parameters were similar between Control calves and those fed wheat straw. At slaughter, both solid feeds led to empty forestomach weights heavier than those of Controls without reducing dressing percentage. The reticulorumen was heaviest in calves fed beet pulp, whereas wheat straw promoted omasal development. The administration of beet pulp resulted in a better carcass conformation than did the Control diet or wheat straw, but it had a detrimental effect on carcass color, which was graded as the darkest (P < 0.001). Consistent with this result, meat color of calves fed beet pulp was darker than that of Control calves and those fed wheat straw, because of the higher hematin concentration measured at the muscle level. No differences in carcass and meat color were observed between Control calves and calves fed wheat straw. The administration of solid feeds for welfare purposes does not always prevent the production of veal meat fulfilling the color standards required by the market. There is not a straight-forward relationship between a solid feed's iron content and the "redness" of veal meat, which should be related to the capability of the calves to use the iron provided by the roughage. Copyright © 2002 by American Society of Animal Science

Mattiello, S.;Canali, E.;Ferrante, V.;Caniatti, M.;Gottardo, F.;Cozzi, G.;Andrighetto, I.;Verga, M.

2002 Journal of Animal Science

doi: 10.2527/2002.802367xpmid: 11881926

Abstract The aim of this study was to evaluate the effects of the addition of two roughage sources (wheat straw and beet pulp) to the milk replacer diet of veal calves, in order to reduce stress and improve animal welfare. We allocated 138 Polish Friesian male calves to three different feeding plans: a milk replacer diet (Control), 250 g/d of wheat straw in addition to the milk replacer, or 250 g/d of dried beet pulp in addition to the milk replacer. Within each feeding treatment, 16 calves were individually housed and 30 were kept in group pens (five calves/pen). Several behavioral, physiological, and health welfare indicators were monitored throughout the fattening period, which lasted for 160 d. Abnormal oral behavior around the meals was higher in Control calves (P < 0.01), while its lowest level was observed in straw-fed calves. At the beginning of the trial, chewing was higher in calves receiving solid feeds (P < 0.001), but the difference from the Control gradually decreased and disappeared at wk 13 for calves fed beet pulp and at wk 17 for those fed wheat straw. At the end of the fattening period, no differences among treatments were found in the frequency of chewing. Regardless of the diet, self-grooming decreased with age and no relationship was observed between this behavior and the presence of rumen hairballs. Cross-sucking was performed with low frequencies (from 4.70% at wk 2 to 1.05% at wk 23 around the meals, and even lower far from the meals) and was not affected by the provision of roughage. The time in contact with the bucket during the whole day was higher in Controls, whereas calves fed wheat straw maintained a lower level of this activity until the end of the trial (P < 0.01). The calves fed wheat straw spent more time in contact with the feed trough (P < 0.001) than those fed beet pulp and Control calves. No differences were found in cortisol curves due to the feeding treatment. In calves fed beet pulp, most hematological measures statistically differed from the other treatments, possibly in response to the higher iron intake and(or) to the higher hemoconcentration, probably due to the administration of beet pulp as dried feed. The incidence of abomasal ulcers and erosions was increased by the provision of the solid feeds, particularly by a structured fiber source such as straw. A roughage source able to satisfy calves' behavioral needs and to improve digestive processes without damaging the digestive apparatus still has to be identified. Copyright © 2002 by American Society of Animal Science

Georgsson, L.;Svendsen, J.

2002 Journal of Animal Science

doi: 10.2527/2002.802376xpmid: 11881927

Abstract The effect of competition at feeding on specific categories of growing-finishing pigs was studied in order to provide an explanation for the increased variation in performance within pens previously seen in highly competitive feeding environments. Individual feed intake and feeding behavior, performance, and health were compared for relatively small, medium, and large pigs in pens of 16. Pens contained either one or two dry feeders during a period of ad libitum eating followed by a period of restricted feeding. Computerized feeders that registered the time and amount of feed consumed by each individual were used. Seven replicate groups on each of the two treatments (a total of 224 pigs) were studied. In the pens with only one feeder, the small pigs ate less (P < 0.05) and tended to have a lower daily weight gain (P < 0.10) than the small pigs in pens with two feeders. However, they had a better feed conversion efficiency (P < 0.05). The small pigs also had a different eating pattern. A considerably larger part of their daily feed intake was consumed during the nighttime hours (P < 0.001) when only one feeder was available rather than two feeders. The large pigs ate more during the restricted period (P < 0.01) and had a lower carcass meat percentage (P < 0.05) in the pens with one feeder. Some differences in feeding behavior between the two levels of competition were seen for all categories of pigs. No difference in health was observed between pigs in the one- and two-feeder pens for any size category of pigs. In conclusion, the inability of the small pigs to get access to feed in combination with overeating by the largest individuals caused the variation in performance seen within pens with a high level of competition at feeding (one feeder for 16 pigs). From a welfare point of view, feeding systems causing a high level of competition may be detrimental when considering all individual pigs in pens, even when it is possible to achieve acceptable production results on average. Copyright © 2002 by American Society of Animal Science