Effect of passive transfer status on preweaning growth performance in dairy lambs

OBJECTIVE: To evaluate the effect of passive transfer status, determined by measuring serum IgG concentration 24 hours after parturition, on preweaning growth performance in dairy lambs. DESIGN: Prospective observational study. ANIMALS: 20 healthy Sardinian dairy lambs. PROCEDURES: Serum IgG concentration was measured 24 hours after birth. Body weight was measured at birth and at the time of weaning 28 days (ie, 27 to 29 days) after birth. Mean daily gain from birth to day 28 and day 28 weight were used as measures of preweaning growth performance. Regression analysis was used to evaluate associations between serum IgG concentration 24 hours after birth and measures of preweaning growth performance. RESULTS: Mean +/- SD serum IgG concentration 24 hours after birth was 24.6 +/- 17.5 mg/mL. Mean body weights at birth and weaning were 2,696 +/- 937 g and 9,253 +/- 2,116 g, respectively, and mean daily gain was 234 +/- 63 g/d. No significant association was detected between serum IgG concentration 24 hours after birth and birth weight. However, serum IgG concentration 24 hours after birth was significantly associated with mean daily gain (R(2) = 0.25). Each 1 mg/mL increase in serum IgG concentration 24 hours after birth was associated with a 1.8 g/d increase in mean daily gain and a 60.8-g increase in day 28 weight. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that passive transfer status, determined as serum IgG concentration 24 hours after birth, was a significant source of variation in preweaning growth performance in dairy lambs.     

影响哺乳期羔羊生长的母羊因素分析

为探索母羊因素对哺乳期云上黑山羊羔羊生长发育的影响,根据母羊体重、胎次分别选取云上黑山羊初生羔羊90只和120只,公、母各半,从出生开始直至90日龄断奶,每10天进行1次体重测定,进行生长发育分析.结果表明:①母羊产后体重对羔羊初生重、哺乳期体重具有显著影响(P<0.05).母羔中,38～45 kg母羊组和48～62 ...     

Comparative studies on growth traits of Sanga and Friesian-Sanga crossbred calves raised on natural pasture on the Accra Plains of Ghana

Data collected from 1993 to 2006 at the Animal Research Institute of Ghana was used to compare the performance of Sanga and Friesian-Sanga crossbred calves on natural pasture. Performance traits analyzed were birth weight (BWT), weaning weight adjusted to 210 days (WW7), preweaning average daily gain to 210 days (ADG 1), weight at 12 months adjusted to 365 days (W12), weight at 18 months adjusted to 540 days (W18) and postweaning average daily gain (ADG 2, from weaning to 540 days). Effects in the model describing these traits were breed, season, sex and first-order interactions between these effects. With the exception of heavier birth weight of Friesian-Sanga crossbred calves (19.98 kg vs. 19.18 kg), body weights of Sangas at weaning, 12 months and 18 months exceeded those of the Friesian-Sanga crossbred calves by 3.76 kg, 35.06 kg and 46.24 kg respectively. The Sangas were also superior in preweaning average daily gain (0.35 kg/day vs. 0.26 kg/day) and postweaning average daily gain (0.28 kg/day vs. 0.21 kg/day). There was a tendency of increasing weight difference between the two breeds with advancing age. It was suggested that improved nutrition such as supplementary feeding would be necessary for crossbreds to express their potential for growth.     

Guinea-pig productivity under traditional management

Results of a 12 month study of traditional guinea-pig production in the western highlands of Cameroon are reported. The mean age of guinea-pigs (Cavia porcellus L.) at first parturition, kidding interval and litter size at birth were 126.30±10.40 d, 64.8±1.70 d and 1.63±0.26 kids respectively. The annual reproductive rate was 9.18 kids/breeding doe while the doe post-partum weight was 530 g. Mean body weights at birth, presumed weaning (21 d) and 15 weeks of age were 78.36±3.20, 147.51±8.10 and 418.88±32 g respectively. Type of birth and sex had a significant effect on body weight at all ages. Birth weight dropped significantly from 83.88±2.87 g for singles to 81.57±3.40 g for twins, 74.25±2.39 g for triplets and 73.75±4.12 g for quadruplets. These differences were maintained to maturity (15 weeks). Males were generally heavier than females. Mortality rates were relatively high among kids: 24% at birth, 39% at 3 weeks and 40% at 15 weeks. Productivity indices were 0.827 kg of young weaned per doe per year, 1560 g of young weaned per kg of doe per year and 2.52 kg of young weaned per kg metabolic weight (kg^0.75) of female per year.     

Sheath area in Brahman and grade Brahman calves and its association with preweaning growth traits

Data from 439 Brahman (B) and grade Brahman (GB; 7/8 Brahman or more) calves born from 1970 through 1975 at the USDA Subtropical Agricultural Research Station were used to estimate least-squares means, heritabilities and genetic correlations for sheath area and preweaning growth traits. Grade Brahman calves weighed more (P less than .01) at birth and gained more (P less than .01) preweaning than B calves, although sheath areas were not different. Males exceeded (P less than .01) heifers in all preweaning growth traits and had larger (P less than .01) sheath areas. Heritabilities were: sheath area, .45 +/- .13; birth weight, .25 +/- .13; average daily gain, .38 +/- .15 and weaning weight, .35 +/- .15. Genetic correlations between sheath area and birth weight, average daily gain and weaning weight were .23 +/- .35, .58 +/- .25 and .52 +/- .27. These results suggest selection could be effective in reducing sheath area in B and B-derivative breeds, but would be antagonistic to preweaning growth traits. Because of relatively low phenotypic correlations between sheath area and preweaning growth rate (.27) and weaning weight (.29), continued emphasis on increasing growth rate or weaning weight could generally be maintained with careful attention to avoiding large sheath areas through independent culling level or index selection procedures.     

Genetic parameter estimates for preweaning traits of beef cattle in a stressful environment

Data collected from 1957 through 1985 from a Hereford herd located in the Southwest were analyzed separately for each sex to evaluate the heritabilities of and genetic correlations among preweaning growth traits within groups of environmentally similar years. Data were grouped into years with poor, moderate and good environments based on contemporary group means for male calves' weaning weight. A total of 7,690 records were analyzed for birth weight, weaning weight and preweaning daily gain with a model that included year of birth, sire within year of birth, age of dam and a covariate of day of birth for birth weight or age at weaning for the weaning traits. Year of birth was a significant source of variation in all environments for all traits, accounting for more of the variation in the good and poor years than in moderate years. Heritability estimates for all traits were greater in good and moderate years than in poor years for bull calves. For heifers, however, estimates for weaning weight and preweaning daily gain were greater in the poor environment. Genetic correlations among birth weight and preweaning gain increased from the good environment to the poor environment (-.49 +/- .26 to .82 +/- .56 for male calves and -.09 +/- 2.6 to .46 +/- .25 for female calves) but phenotypic correlations were near zero in all environments.(ABSTRACT TRUNCATED AT 250 WORDS)     

Birth to weaning kid traits from a complete diallel of Boer, Kiko, and Spanish meat goat breeds semi-intensively managed on humid subtropical pasture

Boer, Kiko, and Spanish meat goats were semi-intensively managed in a complete 3-breed diallel mating scheme to evaluate genetic effects on preweaning kid performance. Over a 6-yr period, 1,547 kids were born in March and May with 1,173 kids raised by their dams to weaning at 3 mo of age. March-born kids were lighter (P < 0.01) at birth, but had greater (P < 0.01) preweaning ADG and survival rates and heavier (P < 0.01) weaning weights than May-born kids. For birth weight, the direct Boer effect was positive (P < 0.01) and direct effects were negative (P < 0.01) for Kiko and Spanish. The direct Kiko effect for preweaning ADG was positive (P < 0.05), whereas other direct breed effects for ADG and all direct effects for weaning weight did not differ from 0 (P > 0.10). Maternal Boer effects were negative (P < 0.01) for birth weight and weaning weight, whereas maternal Kiko effects were significantly (P < 0.05) positive for preweaning ADG and weaning weight. Maternal Spanish effect was positive (P < 0.05) for birth weight, but did not differ from 0 (P > 0.5) for preweaning ADG or weaning weight. Heterosis for birth weight was exhibited (P < 0.01) for each pair of breed crosses, but only between Boer and Kiko for ADG and weaning weight. Kiko and Spanish dams had greater (P < 0.01) preweaning kid survival rates than Boer dams, but the former 2 did not differ (P = 0.72). Significant genetic variation was observed between meat goat breeds for kid performance to weaning. Maternal breed effects were more influential than direct breed effects. Boer goats were not superior to Kiko or Spanish for preweaning kid performance when semi-intensively managed on humid, subtropical pasture. Kiko should be a preferred breed and to a lesser extent Spanish for enhancing birth to weaning kid performance. Findings of this study emphasize the importance of proper doe breed selection in achieving desired kid performance to weaning in meat goats.     

Energy and protein requirements for maintenance and growth of Boer crossbred kids

Meat production by goats has become an important livestock enterprise in several parts of the world. Nonetheless, energy and protein requirements of meat goats have not been defined thoroughly. The objective of this study was to determine the energy and protein requirements for maintenance and growth of 34 (3/4) Boer x (1/4) Saanen crossbred, intact male kids (20.5 +/- 0.24 kg of initial BW). The baseline group was 7 randomly selected kids, averaging 21.2 +/- 0.36 kg of BW. An intermediate group consisted of 6 randomly selected kids, fed for ad libitum intake, that were slaughtered when they reached an average BW of 28.2 +/- 0.39 kg. The remaining kids (n = 21) were allocated randomly on d 0 to 3 levels of DMI (treatments were ad libitum or restricted to 70 or 40% of the ad libitum intake) within 7 slaughter groups. A slaughter group contained 1 kid from each treatment, and kids were slaughtered when the ad libitum treatment kid reached 35 kg of BW. Individual body components (head plus feet, hide, internal organs plus blood, and carcass) were weighed, ground, mixed, and subsampled for chemical analyses. Initial body composition was determined using equations developed from the composition of the baseline kids. The calculated daily maintenance requirement for NE was 77.3 +/- 1.05 kcal/kg(0.75) of empty BW (EBW) or 67.4 +/- 1.04 kcal/kg(0.75) of shrunk BW. The daily ME requirement for maintenance (118.1 kcal/kg(0.75) of EBW or 103.0 kcal/kg(0.75) of shrunk BW) was calculated by iteration, assuming that the heat produced was equal to the ME intake at maintenance. The partial efficiency of use of ME for NE below maintenance was 0.65. A value of 2.44 +/- 0.4 g of net protein/kg(0.75) of EBW for daily maintenance was determined. Net energy requirements for growth ranged from 2.55 to 3.0 Mcal/kg of EBW gain at 20 and 35 kg of BW, and net protein requirements for growth ranged from 178.8 to 185.2 g/kg of EBW gain. These results suggest that NE and net protein requirements for growing meat goats exceed the requirements previously published for dairy goats. Moreover, results from this study suggest that the N requirement for maintenance for growing goats is greater than the established recommendations.     

Preweaning efficiency for mature cows of breed crosses from tropically adapted Bos indicus and Bos taurus and unadapted Bos taurus breeds

Production data were collected on mature cows produced by mating Angus and Hereford (pooled AH), Brahman (Bh) and Boran (Br), and Tuli, a tropically adapted Bos taurus, sires by AI or natural service to Angus and Hereford cows. These cows were mated to Charolais bulls for the purpose of this study. Within each sire breed of cow, cows were assigned randomly to one of three feeding rates, 49 or 76 g of DMI/ BW0.75 or ad libitum (10 to 12 cows/feeding rate group), with weekly individual animal feed consumption recorded. Lactation yields were recorded via the weigh-suckle-weigh protocol at approximately 14, 28, 56, 84, 112, 140, 168, and 196 d postpartum for each cow/calf pair. Means for milk yield at peak lactation, total milk yields, calf birth weight, age-adjusted weaning weights, preweaning daily gain, and feed efficiency were estimated. Peak yield (kg/d) for Bh (10.3 +/- 0.36) was greater (P < 0.05) than for Tuli (9.0 +/- 0.31). Total yield (kg, 212 d) for Bh (1802 +/- 68) was greater (P < 0.05) than for Tuli (1532 +/- 59). Birth weight of AH (44 +/- 0.9) was heavier than for Bh and Br (P < 0.05). Preweaning daily calf gain (g/d) and adjusted weaning weight (kg) of Bh (813 +/- 28, 212 +/- 6.1) and Br (766 +/- 24, 202 +/- 5.1) differed (P < 0.05) from AH (589 +/- 24, 169 +/- 5.2) and Tuli (634 +/- 24, 176 +/- 5.3). Efficiency estimates (grams of adjusted weaning weight/kilograms DMI of the cow) for Bh (88 +/- 2.5) and Br (85 +/- 2.1) exceeded (P < 0.05) those for Tuli (74 +/- 2.1) and AH (73 +/- 2.1). Bos indicus breed crosses exhibited greater peak and total yield, lower birth weight, greater daily gain and adjusted weaning weight, and higher feed efficiency than did Bos taurus breed crosses (P < 0.05). Total yield, daily gain, adjusted weaning weight, and feed efficiency were higher (P < 0.05) for cows sired by bulls from tropically adapted breeds, and the peak yield was less (P < 0.10). Tuli exhibited lower total yield and birth weight than did Angus/Hereford (P < 0.05). The efficiency of crossbred Tuli cows did not differ from Angus/Hereford F1 females, but neither equaled the efficiency of crossbred cows produced using Bos indicus breeds.     

Assessment of the effect of gastrointestinal nematode infestation on weight gain in grazing beef cattle

OBJECTIVE: To assess the effect of subclinical, naturally acquired gastrointestinal nematode infestation on weight gain in yearling cattle kept on pasture. DESIGN: Prospective study. ANIMALS: 799 Bos taurus yearlings kept on pasture with 2,805 herd mates in eastern and central South Dakota. PROCEDURE: 11 trials were initiated at 9 sites from 1999 through 2001. For each trial, approximately 10% of cattle in each site's pasture group were identified, weighed, and administered a bolus of ivermectin (sustained-release formulation) prior to turnout. A similar subgroup of nontreated control cattle was identified and weighed prior to turnout. For each trial, treated and control groups remained with the larger pasture group throughout the entire grazing season. At the end of the grazing season, weight measurements and fecal samples were obtained from all treated and control cattle; average daily grazing gain was calculated and compared between these 2 groups. RESULTS: Treatment of grazing cattle with ivermectin increased average daily gain by 0.0459 +/- 0.01 kg/head/d (mean +/- SEM; 0.1 +/- 0.02 lb/head/d), compared with that achieved in control cattle. Control cattle had significantly greater fecal egg counts at grazing season end than treated cattle. CONCLUSIONS AND CLINICAL RELEVANCE: Compared with anthelmintic-treated cattle, yearling cattle with naturally occurring gastrointestinal nematode infestations kept on pasture in the US Northern Plains had a decreased average daily gain equivalent to 6.6 kg (14.5 lb) less gain in a 143-day grazing season. Strategies for control of nematode populations in pastures should be considered to ameliorate this production loss.     

The Role of Bioactive Tannins in the Postpartum Energy Retention and Productive Performance of Goats Browsed in a Natural Rangeland

The role of bioactive tannins in browse in the postpartum performance of goats grazed under natural range conditions was studied using 40 yearling Mubende goats (20+/-0.32 kg). In a completely randomized design, goats of one group (n = 20) received a daily drench of 50 g per goat of polyethylene glycol (PEG) of molecular weight 4000 given as a condensed tannin (CT) deactivator, and goats of the other group (n = 20) acted as the control (no PEG). Mean birth weights, live weight gains, abortion and twinning rates, litter size and tissue energy retention were measured. The PEG drench resulted in lower postpartum weight gains and tissue energy retention (p < 0.05). Postpartum weekly weight loss per doe was 0.65 kg in the PEG group and 0.46 kg in the control group, while tissue energy loss was 17.7 MJ per goat in the PEG group and 10.23 MJ per goat in the control group in the first 8 weeks. Net weight gain was observed in the control group at the 11 th week but was delayed in the PEG group (15th week). The PEG group had lower birth weights and higher kids mortalities (p <0.05). Selective feeding in the Ankole rangeland exposes goats to beneficial concentrations of dietary CT with apparent cumulative effects leading to improved postpartum performance of does and kids.     

Mass selection for increased 70-day weight in a closed line of Landrace pigs

Mass selection for increased weight at 70 d of age was practiced for six generations in a line of Landrace pigs. It was desired to have the next generation sired by the heaviest nine boars and out of the heaviest 27 gilts. A contemporaneous, randomly selected (by pedigree) control line was maintained in which the next generation was sired by five boars and out of 10 gilts. Inbreeding coefficients were .208 and .214 for the selected and control line litters and .177 and .189 for the selected and control line dams in the sixth generation, respectively. A total of 1,906 pigs was farrowed with 70-d weights collected on 1,267 pigs. These pigs were sired by 88 boars and out of 190 gilts. The generation interval was 13 mo. Six traits were studied: birth, 21-d, 35-d and 70-d weights and preweaning (from birth to 35 d) and postweaning (from 35 to 70 d) daily gains. Direct and correlated responses per generation and per weighted cumulative selection differential (WCSD) were estimated. Total WCSD for 70-d weight was 30.3 kg. This corresponds to a standardized WCSD of 6.11 phenotypic standard deviations. The response per generation for 70-d weight was .65 +/- .29 kg. The realized heritability for 70-d weight was .13 +/- .06. Nearly all the increased weight at 70 d was the result of more rapid growth in the postweaning period, with little difference in growth in the preweaning period; birth, 21-d and 35-d weights and preweaning daily gains remained unchanged by selection for 70-d weight.     

Effect of dietary crude protein level on the reproductive performance and growth of New Zealand white rabbits

An experiment utilizing 391 preweaning and 187 postweaning litter records from 145 does was conducted for 12 mo to determine the effect of dietary crude protein level on performance of commercial New Zealand White rabbits. Does and their litters were fed alfalfa-based pelleted diets containing either 17.5, 19 or 20.5% crude protein (CP). In a separate experiment, the 17.5 and 20.5% CP diets were fed during lactation to 10 does to determine nitrogen (N) digestibility and retention. Body weights of does fed 17.5% CP were lower (P less than .01) than for the other treatments after 21 and 28 d of lactation. No differences (P greater than .10) were observed for doe weight at kindling, percentage fertility, litter size, preweaning litter mortality, 1- to 21-d consumption, preweaning feed efficiency and 28- to 56-d average daily consumption, average daily gain and average weight. Total born tended to be higher (P = .07) on higher protein levels but percentage born alive was greatest (P less than .01) on the 17.5% CP diet. Does fed 19% CP tended to have a greater number of parities (P = .06). Other significant differences observed for preweaning litter traits were between 17.5 and 19% CP groups. Does fed 19% CP had heavier litters at birth (P less than .01), at 21 d (P = .05) and 28 d (P = .06) and had greater 1- to 21-d litter gains and 21- to 28-d consumption (P = .05) than those fed 17.5% CP. For postweaning performance, feed efficiency values were lowest and mortality was highest for litters fed 20.5% CP. When litters were switched to different diets after weaning, mortality tended to be higher (P = .07) for animals that were fed 20.5% CP before weaning. The month of experiment effect did not influence any of the characters studied (P greater than .05). Parity number was important for percentage fertility, percentage born alive, litter birth weight and doe weight at 21 and 28 d (P less than .05). Does at first parity showed the poorest performance for all traits (except percentage fertility). Fertility fluctuated throughout the first four parities and then steadily declined. Does fed 20.5% CP had greater apparent dry matter and acid detergent fiber digestibilities and N intakes (P less than .05) and retained 90% more N during lactation (P = .22) than does fed 17.5% CP. Milk production and CP digestibility did not differ between the two diets tested.(ABSTRACT TRUNCATED AT 400 WORDS)     

Economic analysis of feeding pasteurized nonsaleable milk versus conventional milk replacer to dairy calves

OBJECTIVE: To determine growth, morbidity, and mortality rates in dairy calves fed pasteurized nonsaleable milk versus commercial milk replacer and compare economics of feeding pasteurized nonsaleable milk versus commercial milk replacer in dairy calves. DESIGN: Clinical trial. ANIMALS: 438 dairy calves. PROCEDURE: Calves were assigned at 1 to 2 days of age to be fed pasteurized nonsaleable milk or a commercial milk replacer until weaned. Body weight was measured at the time of study enrollment and at the time of weaning, and any medical treatments administered and deaths that occurred prior to weaning were recorded. A partial budget model was developed to examine the economics of feeding pasteurized nonsaleable milk versus commercial milk replacer. RESULTS: Calves fed conventional milk replacer had significantly lower rates of gain (-0.12 kg/d [-0.26 lb/d]), lower weaning weights (-5.6 kg [-12.3 lb]), higher risk for treatment during the summer and winter months (odds ratio [OR], 3.99), and higher risk of death during the winter months (OR, 29.81) than did calves fed pasteurized nonsaleable milk. The estimated savings of feeding pasteurized nonsaleable milk, compared with milk replacer, was dollars 0.69/calf per day. The estimated number of calves needed to economically justify the nonsaleable milk pasteurization system was 23 calves/d. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that dairy calves fed pasteurized nonsaleable milk have a higher growth rate and lower morbidity and mortality rates than do calves fed conventional milk replacer. Feeding pasteurized nonsaleable milk could be an economically viable strategy for dairy calf producers.     

Selection for postweaning growth in inbred Hereford cattle: the Fort Keogh, Montana line 1 example.

Demographic characteristics and genetic trends in birth weight and pre- and postweaning ADG were examined in a population of Hereford cattle (Line 1). Line 1 was founded largely from two paternal half-sib sires and has been selected for postweaning growth. There were pedigree records on 951 members of the base population that predated 1935, when data collection began. Numbers of records analyzed using mixed-model methodology were 4,716 birth weight, 4,427 preweaning ADG, and 3,579 postweaning ADG. Birth weight and preweaning ADG were considered to have direct and maternal genetic components. Inbreeding accumulated rapidly from 1935 to 1960 and more slowly (.22%/yr) thereafter. Any reduction in additive genetic variance due to inbreeding and selection may have been offset by a concurrent reduction in generation interval that was observed as time progressed. Expected selection differential for 365-d weight, averaged over sexes, was 31.2 kg per generation. For birth weight, annual genetic trends in direct and maternal effects were 42 +/- 3 g and 15 +/- 3 g, respectively. Annual direct and maternal genetic trends for preweaning ADG were .70 +/- .06 g/d and .63 +/- .06 g/d, respectively. Direct response in postweaning ADG was linear and equal to 5.3 +/- .6 g.d-1.yr-1. As a result, estimated breeding values of birth weight, 200-d weight, and 365-d weight increased by 3.2 kg, 14.5 kg, and 62.4 kg, respectively, from 1935 to 1989. Selection within Line 1 was effective in increasing genetic potential for growth over 13 generations. No selection plateau was observed in any of the traits examined.     

Correlated responses in reproductive and carcass traits to selection for 70-day weight in Landrace swine.

Correlated responses in reproductive and carcass traits were studied in 181 litters and 218 pigs from a line of Landrace pigs selected six generations for increased weight at 70 d of age and a contemporaneous, randomly selected control line. The reproductive and maternal traits studied included litter sizes born, born alive, and alive at 21 d and litter weight at birth and at 21 d. Carcass traits studied were carcass length, longissimus muscle area, average backfat thickness, 10th-rib backfat thickness, specific gravity, weights of closely trimmed ham, loin, and shoulder, belly weight, subjective scoring of the longissimus muscle for color and marbling, estimated percentage of muscle, and lean gain per day. Total weighted cumulative selection differential for 70-d weight was 30.2 kg. The realized heritability for 70-d weight was .13 +/- .06, and the change in 70-d weight was .65 +/- .29 kg per generation. The regression coefficient of litter size at 21 d on generation was .24 +/- .10 (P less than .10) pigs per generation. None of the other regression coefficients for the reproductive traits differed from zero. Carcass length, specific gravity, and ham weight decreased (P less than .10) -.075 +/- .036 cm, -.00054 +/- .00027, and -.102 +/- .048 kg, respectively, per generation. Color score and lean gain per day increased .046 +/- .021 points and .0032 +/- .0013 kg/d, respectively, each generation in response to the selection.(ABSTRACT TRUNCATED AT 250 WORDS)     

Protein and Energy Requirements of Pre-weaned West African Dwarf Goats Fed Soyabean Diet as a Replacement for Milk in a Tropical Environment

Twenty-one early-weaned West African dwarf goats weighing between 1.0 and 1.5 kg at birth were used to assess the protein and energy requirement of pre-weaned West African Dwarf (WAD) goats fed soyabean diet. Three isonitrogenous diets (24%) were prepared such that dried whole-milk protein was replaced by corn starch and soyabean concentrate protein at 0.0%, 25.0% and 50.0% levels such that a 14.5% total solid solution was obtained for each diet. Results indicated that a daily digestible energy (expressed as kcal/day/W0.75 kg) intake of 58.2, 63.7, 98.5 and 114.6 kcal was required for maintenance, while a corresponding value of 7.37, 4.50, 2.18 and 1.91 kcal was required per day per gram live weight gain by the kids at 4, 6, 9 and 13weeks old, respectively. Similarly, a digestible crude protein (DCP) intake of 3.59 g/day/W0.75 kg) appeared to be adequate for maintenance of the kids between 0 and 13 weeks, while 0.34 g/day/W0.75 kg of DCP intake was required per day per gram live weight.     

Prognostic indicators of post partum viability of kids born to Escherichia coli-vaccinated or unvaccinated does

This study was undertaken to determine some blood and other physiological parameters with potential for use as prognostic indicators of viability of newborn goat kids. Of the 143 kids born during the on-farm study, 97 were crosses of Galla x Small East African (SEA) and 46 were pure SEA. The SEA x Galla kids were 46 single males, with a mean body weight at birth of 2.77 +/- 0.22 kg, 43 females with a mean body weight at birth of 2.36 +/- 0.76 kg and 5 and 3 sets of female and male twins (mean body weight at birth of 1.8 +/- 0.19 kg and 2.05 +/- 0.07 kg for the female and male kids, respectively). The SEA kids comprised 36 single male and female kids (mean body weight at birth of 2.48 +/- 0.04 kg and 10 sets of twins (both male and female) (mean body weight at birth of 1.50 +/- 0.04 kg ). Pre-suckling sera obtained on-station from kids born of does vaccinated against Escherichia coli (n = 8) and unvaccinated does (n = 7) had a total protein content of <40.0 g/l and no detectable levels of IgG and A or E. coli antibodies. Sera obtained 12 hours post partum) from kids that survived in both groups contained about 19-22 g of Ig g/l, 50-80 g total protein/l, blood glucose of >5 mmol/l and had an E. coli antibody titre of between 1/160 and 1/640. On the other hand, kids that died within 48 hours of birth (parturient deaths) and had been classified in categories 3 and 4 righting reaction had low (<40 g/l) total protein, low white blood cell count (4,000/ml) and low blood glucose concentration (<4.9 mmol/l). It is concluded that kids with delayed righting reaction (>45 minutes), low rectal temperature (<36 degrees C), low birth weights (<1.5 kg for singles and <1.0 kg for twins), low white blood cells (<4,000/ml), low (<2 mmol/l) blood glucose levels, low total protein (<40.0 g/l), low (<1:160) E. coli antibody titre and IgG (< or =3,350 mg/l) in sera obtained 12 hours after birth have a poor prognosis for survival.     

Experimental selection for calving ease and postnatal growth in seven cattle populations. II. Phenotypic differences

Effects of selection for 2-yr-old heifer calving ease (reduced calving difficulty score) on phenotypic differences between select and control lines of cattle for birth, growth, yearling hip height, and pelvic measurements were estimated. The selection objective was to decrease calving difficulty score in 2-yr-old heifers, while either maintaining or increasing yearling weight. The control line objective was to maintain or increase yearling weight by the same amount as the select lines and to maintain or proportionally increase birth weight. Select and control lines were formed in 4 purebred and 3 composite populations. Selection began in 1992 and select (n = 6,926) and control (n = 2,043) line calves were born from 1993 through 1999. Selection was based on EBV calculated from a 4-trait BLUP with observations on 2-yr-old calving difficulty scores, birth weight, weaning weight, and postweaning gain. Calving difficulty was scored on a scale from 1 (unassisted) to 7 (caesarean). All birth traits in select lines differed significantly from control lines. Averaged over 7 yr, select lines calved 3.0 +/- 0.5 d earlier, had 1.8 +/- 0.5 d shorter gestations, were 2.99 +/- 0.32 kg lighter at birth, had 5.6 +/- 1.5% fewer calves assisted at birth (averaged across dam ages), and 2-yr-old heifers had 0.80 +/- 0.08 lower calving difficulty score. Select lines averaged 19.8% lower 2-yr-old heifer calving assistance, but there was no difference in calving assistance of older cows, resulting in a highly significant interaction of selection and dam classification. Preweaning ADG was increased 15 +/- 9 g/d (1.7%) in select lines. Increased preweaning gain offset decreased birth weights in select lines, resulting in weaning weights that did not differ (P = 0.71). Postweaning ADG (P = 0.16) and yearling weight (P = 0.41) also did not differ. Increased preweaning ADG in select lines was not maintained after weaning. Select line hip heights were 0.70 +/- 0.21 cm shorter when measured as yearlings. Pelvic height, width, and area of select heifers measured 25 to 74 d after yearling weights were not significantly different. The differences between select and control lines significantly changed over the course of the experiment for some traits. In the final 2 yr of the experiment, select lines had 3.9 kg lower birth weight and 1.3 cm shorter hip heights. Selection can be used effectively to reduce 2-yr-old calving difficulty and calving assistance while maintaining or increasing yearling weight.     

Vaccination of weaned pigs against oedema disease

The trial was performed in a pig-production unit with high prevalence of postweaning oedema disease (ED). An experimental inactivated VT2e-toxoid vaccine was produced. Two randomised treatment groups of piglets were formed. The animals in one group (n = 351) were vaccinated intramuscularly at 1 week of age with 12.5 micrograms and at 3 weeks of age with 25 micrograms of inactivated VT2e toxin. The other group (n = 350) was placebo treated. We evaluated: average daily nursery weight gain, nursery mortality due to ED, fattening average daily weight gain until slaughter and VT2e-specific antibody titres. Serological tests were performed four times: before first vaccination, at weaning, at the end of nursery period and at an age of 4 month. Vaccination improved nursery average weight gains (301 +/- 31 g/day vs. 278 +/- 41 g/day). Mortality due to edema disease decreased in vaccinates: 0.9% vs. 6.9%. Fattening average daily weight gain until slaughter did not differ between the groups (711 +/- 41 g vs. 708 +/- 46 g).