Post-weaning Performance Research Articles

The effect of type of suckling on the pre- and post-weaning lactation performance of Damascus goats and the growth rate of the kids

SummaryForty-nine and 58 Damascus goats were used in each of two trials, respectively. Goats were randomly allocated 2 days post-partum to twin-suckling (TS), singlesuckling (SS) and no-suckling (NS) kids treatments. In trial 1, artificially reared kids were divided into two groups fed either on ewe-milk (25·8% fat, 24·2% protein) or on calf-milk (15% fat, 22·5% protein) replacer. In trial 2, all artificially reared kids were fed on ewe-milk replacer. The ewe- and calf-milk replacers were reconstituted in the ratio of 1 part powder to 5 or 4 parts (by weight) of water, respectively.Separation of kids from their dams reduced total milk yield (means of two trials) until weaning (TS 194, SS 176, NS 121 kg/goat) and from weaning to 90 days of lactation (TS 95, SS 89, NS 70 kg/goat). On the other hand, separation of kids increased marketable milk yield until weaning (TS 68, SS 99, NS 121 kg/goat). Marketable milk during the period 3–90 days post-partum was similar for NS and SS goats (TS 163, SS 188, NS 191 kg/goat). Goats suckling two kids suffered greater weight losses (TS 78, SS 44, NS 6 g/day). Goats suckling two males produced more milk until weaning than all other twin sets. Differences in concentrate intake between group means of TS and SS were smaller compared with the NS group (TS 2·26, SS 2·08, NS 1·86 kg/goat per day).There were no differences in weaning weight and weight gain from birth to weaning between kids reared on milk replacers. However, four kids on the calf-milk replacer died and two more were excluded from the data because of severe scouring. Single suckling kids gained more weight until weaning than TS and those reared artificially (AR) on ewe-milk replacer (SS 11·1, TS 9·1, AR 9·3 kg/kid). Furthermore, males consumed more milk than females (males 74, females 64 kg/kid) and SS more than TS kids (SS 75, TS 63 kg/kid).It is concluded that SS and NS treatments increase commercial milk yields compared with the TS goats, but NS should not be recommended because of an adverse effect on pre- and post-weaning lactation performance.

Genetic effects on maternal performance and litter pre-weaning and post-weaning traits in rabbits

AbstrtactFlemish Giant (FG) and New Zealand White (NZW) purebreds and terminal crossbreds (TX) (Flemish Giant sires × Florida White-New Zealand White dams) were evaluated during a 10-month period for maternal and litter pre-weaning and post-weaning performance. For the doe traits studied, teat number was greatest and litter interval was shortest, while body weight at breeding age (154 days), litter weight at 21 days and day 1 to 21 food intake were lowest for crossbred does. These traits were similar for pure doe groups, with the exception of body weight, for which FG does were heavier. For the preweaning litter traits examined (no. = 101 litters), litter size born was smallest in the TX group (the purebred groups being similar) and was largest at weaning (28 days) for NZW. Proportion of kits born alive was lowest in FG litters, while the NZW and TX groups were comparable. Litter and average birth and weaning weights, litter daily gain, and doe and litter food intake (1 to 28 days) were all highest in FG litters and lowest in TX litters. Repeatability estimates (t) were low (t < 0·05) for litter size and birth weight traits, and were moderate to high (0·18 < t < 0·58) for the remaining maternally influenced characters. For the post-weaning litter traits studied (no. = 86 litters), NZW litters were larger in number and heavier at market age (56 days), and consumed more food from 28 to 56 days than FG and TX litters. Purebred FG litters, however, had heavier average market weights per rabbit, while purebred NZW and TX litters were similar. Mortality due to respiratory disease was higher in FG litters than in NZW and TX litters. Total mortality incidence was lowest in the TX group.

The effect of dietary metabolizable energy concentration upon the pre- and post-weaning performance of growing rabbits

ABSTRACTTwenty-five Californian does were mated and given pelleted diets of either 8(LE) or 10(HE) MJ/kg dry matter (ruminant metabolizable energy values) throughout gestation and lactation. Litter sizes were adjusted to six offspring per doe. Milk yield was estimated from the weight differences of the litters before and after suckling, when the opportunity for nursing was confined to once daily. The young rabbits were allowed access to either the LE or HE diets from 18 days of age. Weaning took place at 32 days of age when four rabbits from each doe grouP × pre-weaning diet were slaughtered. Diet had no effect on litter size or birth weight, but does on the LE diet had lower live weights post partum (P < 0·05). Dry-matter consumption by the does on the LE diet was greater than for the HE diet (P < 0·05) both during gestation and lactation, but calculated metabolizable energy intakes were lower during lactation. There were no statistically significant differences between treatments for milk yield or live-weight gain to weaning and dry-matter intakes of the young at weaning, but daily live-weight gain from fostering to 18 days of age was greater for litters of does fed the HE rather than the LE diet (P < 0·05). There were no statistically significant differences between diets for carcass traits at weaning.After weaning, 32 rabbits were given either the LE or HE diet until 2 kg live weight when they were slaughtered. A post-weaning × pre-weaning diet interaction (P < 0·05) occurred for live weights of the rabbits at the start of the post-weaning trial (i.e. after a 10-day adaptation period) with LE: LE rabbits being lighter than other rabbits as a results of poor live-weight gains during the adaptation period. Live-weight gains to slaughter were greater for the pre-weaning LE diet (P < 0·05) and the post-weaning HE diet (P < 0·01), although dry-matter intakes of the HE diet were less (P < 0·05). Rabbits on the LE diet had greater empty gut weights (P < 0·05) and lighter livers (P < 0·05) at slaughter.

Performance of Calves Fed Milk Replacer Once Daily at Various Fluid Intakes and Dry Matter Concentrations

Ninety-six Holstein calves were fed 1 of 12 liquid diets once daily under two feeding options. Diets consisted of milk replacer (22% crude protein, 10% fat) fed at fluid intakes of 6, 8, and 10% body weight and dry matter concentrations of 10, 13, 16, and 19%. Feeding options consisted of calculating fluid intake and dry matter concentration based on initial weight and holding this constant through weaning or adjusting weekly according to change in body weight. Water and a complete calf starter (minimum 15% crude protein) were available ad libitum. Calves were weaned abruptly at 4 wk of age and observed until 6 wk of age for immediate postweaning performance. Fluid intake and dry matter concentration had a positive effect on weight gain during wk 0 to 4. However, during the immediate postweaning period, gain decreased in calves previously fed replacer at the higher intake. Overall gain (wk 0 to 6) was not affected by fluid intake or dry matter concentration. Starter intake decreased with increasing fluid intake or dry matter concentration during wk 4 and wk 0 to 4. Total intakes of dry matter were not affected by treatment. Incidence of scours increased linearly with dry matter concentration, and both fluid intake and dry matter concentration had a positive linear effect on fecal score and duration of scours. Feeding option had no effect on any measures. Calves fed replacer containing between 10 and 13% dry matter and offered at 8% body weight had fewer intestinal disturbances during the replacer feeding period and obtained recommended gains over the entire 6 wk.

RELATIONSHIPS OF SCROTAL CIRCUMFERENCE WITH BODY WEIGHT AND BACKFAT THICKNESS IN MULTIBREED SYNTHETIC POPULATIONS OF YOUNG BEEF BULLS

Relationships of scrotal circumference (SC) with body weight (BW) and backfat thickness (FT) as measured from scanograms were studied. A total of 935 observations on growing multibreed synthetic beef bulls on a postweaning performance test were available from a commercial herd for this study. Significant breed group, period and group × period interaction effects were noted on SC, BW and FT. BW and SC increased significantly during the test in all breed groups, while FT showed no change in three breed groups. Repeatability pooled across groups for SC was estimated as 0.72; 0.66 after adjusting for BW. Significant correlations were noticed between SC and BW within each breed group. Partial correlations between SC and BW at constant FT were not different from gross correlations. Linear regression coefficients of SC on BW were significant in all groups and showed heterogeneity among groups but not between periods within groups. Adjustments of SC for BW should, therefore, be breed group specific. BW alone accounted for considerable variation in SC, from 38 to 76%. Simple correlation coefficients between SC and FT were low and significant in only two groups. A significant but low positive relationship was noted between SC and FT at constant BW in a group fed a high-concentrate diet during the postweaning gain period, but there was no relationship in four other groups. Results indicated that the method of adjusting SC for FT as an indirect way of adjusting for scrotal fat was not satisfactory. Key words: Bulls, scrotal circumference, growth

A note on some factors influencing post-weaning performance of purebred and crossbred lambs

ABSTRACTLive weights at weaning, and 10, 15 and 20 weeks of age, and postweaning gains of 738 lambs (390 males and 348 females) obtained from purebred and crossbred lambs were studied. The main breeds involved were the Cyprus fat-tailed, Chios and Awassi. Male lambswere heavier (P< 0·01) and grew faster (P< 0·01) than female lambs. Singles were heavier (P< 0·01) than other multiples at all ages, which probably reflects differences in initial weight, since no differences were found in growth rate. Crossbred lambs were heavier at 20 weeks of age and had a faster growth rate than purebred lambs. Ewe lactation number significantly affected lamb weaning weights, the heaviest lambs being those from 3- to 5-year-old dams (third and fourth lactation).

Crossbreeding with Africander dam as basis. 3. Post-weaning growth performance of progeny of various sire-breeds

Crossbreeding with Africander dam as basis. 3. Post-weaning growth performance of progeny of various sire-breeds

Genetic Analysis of Postweaning Performance of Hereford Bulls2

The genetic parameters of and interrelations among postweaning performance traits were investigated using feedlot performance records of 695 individually-fed Hereford bulls from 72 sires. The data comprise two generations of selection for weaning weight (line 1), postweaning growth rate (line 2) and a random control (line 3). Estimates of heritability from analyses of within-animal regression coefficients (regression of cumulative gain (B-WT) or feed intake (B-FEED) on the period of measurement) obtained from intermediate, 14-day measurements were higher than for total gain or total feed. Further, the heritability of the ratio of the two regressions (B-FEED/B-WT) was higher than for feed/gain. Heritabilities for B-WT, B-FEED, NEWEF (B-FEED/B-WT), PREDEF1 (total feed/B-WT)and PREDEF2 (B-FEED/total gain) were .41±.26, .52±25, .38±22, .33±.22 and .24±.21, respectively. Heritabilities of point estimates were: .23±.20, .44±.25, .26±25, .21±.23 and .49±28 for ADG (average daily gain), ADFC (average daily feed intake), FEEDEF (feed/gain), FAT(sonoray fat measurement) and FINWT (yearling weight), respectively. High and positive genetic correlations were found between ADG and ADFC (.84), FINWT and ADFC (.55), FINWT and ADG (.71) and ADFC and FEEDEF (.72). FEEDEF and ADG were lowly correlated genetically (.23), whereas FINWT and FEEDEF were genetically independent (−.02). However, the regression coefficient approach produced different results regarding the associations among gain, feed consumption and feed efficiency. The genetic correlations between B-WT and B-FEED, B-WT and NEWEF and B-FEED and NEWEF were .19, −.06 and .12, respectively. Thus the antagonistic correlations were generally reduced by this approach. These results suggest that direct selection will be necessary to improve efficiency. Selection for NEWEF is suggested. Heritability estimates from sire-son analyses were lower than those obtained from paternal half-sib correlations. Hence estimates of the covariance between direct genetic and maternal effects were negative for all traits.

Weaning Age of Angus Heifer Calves as a Factor Influencing Calf and Cow Performance

Effects of weaning calves at 120 and 210 days of age on pre-weaning, post-weaning, reproductive and progeny performance were studied over 6 years in a herd of purebred Angus cattle. There were 895 calves of both sexes in the pre-weaning study with 443 weaned at 120 days of age and placed on self-feed and bluegrass pasture to 210 days of age, while 452 nursed their dams to 210 days of age with no supplemental feed. Post-weaning performance is reported on 458 heifer calves. Reproductive and progeny performance data were recorded and analyzed on 699 parturitions by the 199 heifers selected as herd replacements. Early weaned (120 days) calves exceeded late weaned calves by .18 points conformation score and 10.1 kg 210-day adjusted weight. Late weaned (210 days) heifers gained 11 kg more than early weaned heifers in the post-weaning period which resulted in virtually equal yearling weights for the two weaning age groups. Weaning age of the cow when she was a calf did not affect either her reproductive efficiency or birth weight, 120-day ratio and 210-day ratio of her progeny. Dams of early weaned calves gained 12 kg more than dams of late weaned calves between 120 and 210 days post-partum. This weight gain was mildly associated with greater percentages pregnant and live calves, with earlier calving and with increased calving difficulty the following year. Considering all traits, both systems of weaning (120 days or 210 days) produced similar and satisfactory results. The decision concerning age of weaning can be based largely on management factors.

High-Urea Supplements and Preweaning Creep Feed as Factors Affecting Postweaning Performance of Bulls

Weanling Angus bulls, which had been used in a creep study the last 4 months prior to weaning, were used in a 168-day finishing trial to study their comparative response to high-urea and natural protein supplements. The diet consisted of limited corn silage (7.7 kg), a full-feed of high-moisture shelled corn (5 or 6 kg) plus the daily protein supplement treatments of .9 kg of a 32% natural protein, .45 kg of a high-urea 64% protein or .36 kg of a high-urea 80% protein supplement. Each of the protein supplements compared supplied approximately 45% of the total daily protein intake. The preweaning creep treatments had no effect on rate of gain. The protein supplement treatments had no effect on rate of gain over the 168-day test. Furthermore, carcass data showed no difference among carcasses from the three protein supplements.

Effect of creep feeding oat grain to beef calves on their growth rate, carcase composition and post-weaning performance in a feedlot

Autumn and spring born Hereford calves grazing together with their dams were offered a ration of oaten grain ad libitum in a creep enclosure to which only the calves had access from November to weaning. Similar groups received no oat ration. At weaning the heifers of each age were slaughtered and carcase characteristics were determined. The steers were placed in a feedlot and given a ration of hay and grain until they attained an unfasted weight of 340 kg. The creep fed calves maintained their earlier growth rates after taking the creep ration, whereas the growth rate of the unfed controls declined from this time. Time of birth, creep feeding and sex all affected liveweight gain to weaning. Creep feeding increased the carcase weight of the heifers and also affected dressing percentage, eye muscle area, fat thickness and chemical composition. Creep feeding prior to weaning did not influence the average daily weight gains or feed efficiency of steers subsequently fed a fattening ration in a feedlot but it greatly shortened the feeding period to attain the desired market weight. However, the reduction in feed required would be insufficient to compensate for the oats given during creep feeding. The economics of creep feeding will depend on the price of grain in relation to the value of weaned calves in slaughter condition.

Effects of nitrovin supplementation and the use of pure and F1crossbred boars on the post-weaning performance of growing pigs

Abstract Growth and carcass performance of 60 pigs were recorded between 18 and 54 kg live weight. Nitrovin was included in the diet at the rate of 22 mg/kg of air-dry diet. Pigs fed diets with nitrovin grew faster and required less feed than the unsupplemented controls. Although carcasses of the nitrovin-supplemented group contained less protein and more fat than the controls, there were no differences in backfat depth at the point used for carcass grading. In the second trial, the growth performance of 64 pigs was compared from 18 to 57 kg live weight. Diets containing nitrovin plus copper (250 mg/kg) were offered at two intakes representing 4.0 and 4.71 percent of live weight. The addition of nitrovin to diets already containing copper improved growth performance at the lower feed intake only. Backfat depth was not affected by nitrovin supplementation. The performance of progeny sired by boars of the Landrace and Large White breeds and their Ft cross (Large White × Landrace) was compared in two trials....

The relative performance and carcass characteristics of pigs sired by Hampshire and Large White boars

SUMMARYHampshire and Large White crosses were compared with purebred Large White pigs for litterproduction and post-weaning performance. Crossbreeding did not influence either litter size or total litter weight at birth but crossbred litters had 14 % more pigs at weaning than purebred litters. Total litter weight at weaning was 13 % greater i n crossbred litters. In two post-weaning trials (23 to 90 kg live weight), where feeding was either ad libitum or restricted according to live weight, Hampshire crosses had advantages over Large Whites in rate and efficiency of gain and killing-out percentage. The cross-breds had shorter carcasses but a greater eye-muscle area due primarily to a greater depth of lean in the muscle. All fat depth measurements indicated that the crossbreds were not significantly leaner than the purebreds and this was confirmed in the restricted trial when the carcasses were subjected to physical and chemical dissection. Hampshire carcasses did have a lower bone content than those of the purebreds, but crossbreeding did not influence joint proportions or lean distribution in the carcass.

Evaluating Relationships among Immature Measures of Size, Shape and Performance of Beef Bulls. III. The Relationships between Post-Weaning Test Performance and Size and Shape at Twelve Months

Evaluating Relationships among Immature Measures of Size, Shape and Performance of Beef Bulls. III. The Relationships between Post-Weaning Test Performance and Size and Shape at Twelve Months

Effects of Calf Sex and Age of Dam on Pre- and Post-Weaning Performance of Calves from an Angus-Holstein Crossbred Herd

Effects of Calf Sex and Age of Dam on Pre- and Post-Weaning Performance of Calves from an Angus-Holstein Crossbred Herd

Effectiveness of reciprocal selection for performance of crosses between Montana no. 1 and Yorkshire swine. I. Preweaning traits.

RESULTS from early studies of individual and family selection for litter size and growth rate within inbred lines of swine (Comstock and Winters, 1944; Laben and Whatley, 1947; Kottman, Lush and Hazel, 1948; Fine and Winters, 1952, 1953; Rempel and Winters, 1952) were far from encouraging when adjusted for accumulated effects of inbreeding (Dickerson, 1951). Also, lack of control populations made it impossible to separate genetic response from environmental trends. The apparent lack of response in spite of intensive selection and substantial estimates of heritability, especially for growth rate, suggested direct progeny test selection for increased heterosis (Comstock, Robinson and Harvey, 1949; Dickerson, 1952) in crosses of specific stocks as a possible method for obtaining further genetic improvement in performance of swine. The objective of the experiment was to determine the effectiveness of selection based upon (1) both pure strain and crossbred progeny performance and that (2) based solely upon pure strain performance. Selection was based on both preweaning and post-weaning performance.

Post-weaning performance of calves as affected by longstem hay and method feeding

Post-weaning performance of calves as affected by longstem hay and method feeding

Post-weaning performance of calves as affected by longstem hay and pre-weaning creep feeding

Post-weaning performance of calves as affected by longstem hay and pre-weaning creep feeding

Efecto del consumo de dieta líquida y alimento balanceado sobre el crecimiento y desarrollo ruminal en terneras de lechería

La presente investigación tuvo como objetivo determinar el efecto del consumo de dieta líquida y alimento balanceado sobre el crecimiento y desarrollo ruminal en terneras de lechería. El experimento se llevó a cabo en una finca comercial ubicada a 2500 msnm en la provincia de Cartago, Costa Rica. Diez animales de la raza Holstein se seleccionaron al nacimiento y se incluyeron aleatoriamente en 1 de 2 tratamientos.El tratamiento convencional consistió en ofrecer a los animales una dieta líquida de forma restringida (4 l.animal-1.d-1). El tratamiento intensivo consistió en suministrar a los animales la dieta líquida en mayores cantidades, hasta alcanzar un consumo de 8 l.animal-1.d-1. Se realizaron mediciones semanales de peso, altura a la cruz y a la cadera. Los animales se sacrificaron a las 8 semanas, con el fin de hacer evaluaciones y poder comparar el crecimiento y desarrollo ruminal. Los animales en el tratamiento intensivo presentaron menores consumos de alimento balanceado. No se encontraron diferencias significativas en cuanto al peso corporal, altura a la cruz o altura a la cadera entre tratamientos. Al brindar una mayor cantidad de leche con el tratamiento intensivo, se observó un menor desarrollo del rumen y del crecimiento de sus papilas, lo que puede afectar negativamente el desempeño posdesdete de los animales.

Heterosis from crosses among British breeds of beef cattle: post-weaning performance to slaughter.

Heterosis from crosses among British breeds of beef cattle: post-weaning performance to slaughter.