摘要:

Sons of 19 Red Danish, 19 Danish Friesian, 2 Danish Red and White and 16 Danish Jersey bulls were reared from 6 weeks to 11 months of age on a high concentrate (C) or high roughage (R) diet. Daughters of the same sires were reared on diets formulated to promote low (L), medium (M) or high (H) daily gain from 6 weeks of age to puberty. Heifers then were managed similarly through 250 days of their first lactation. Sire × diet interactions were significant for traits measured in bulls; genetic correlations between the same traits expressed in C-versus R-feeding systems were -0.10 for daily energy intake (DEI), 0.16 for average daily gain (ADG), and 0.18 for efficiency of nutrient utilization (EFF). Heritabilities of these traits were higher when expressed in the R-feeding system than in the C-feeding system (1.09 versus 0.29 for DEI, 0.58 versus 0.28 for ADG, and 0.82 versus 0.34 for EFF), whereas phenotypic variances of the traits were larger under C-feeding. Sire × rearing intensity interactions were not significant for most traits of growing or lactating females. Heritability estimates of DEI, ADG and EFF in females ranged between 0.22 and 0.27; and heritabilities of weight at calving, energy corrected milk yield (ECM), and DEI and EFF during lactation were 0.35, 0.50, 0.16 and 0.69, respectively. Weight change patterns related to post-partum energy balance were lowly heritable (0.14 to 0.23). Genetic correlations of ECM were -0.67 with post-partum weight loss, 0.60 with number of days of lactation when minimum body weight was reached, 0.50 with DEI during lactation, and 0.91 with lactation EFF.

ISSN:0906-4702    

DOI:10.1080/09064709509415835

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Red Danish (RD), Danish Friesian (DF), Danish Red and White (RW) and Danish Jersey (DJ) heifers hadad libitumaccess to total mixed rations designed to promote low (L), medium (M) or high (H) growth rate from 6 weeks of age to approximately the time of puberty. Heifers then were managed uniformly through 250 days of their first lactation. Paternal half-brothers of the heifers were tested from 6 weeks to 11 months of age on a high concentrate or on a roughage diet. For prepubertal feed intake, growth and efficiency of feed utilization of heifers, breed and rearing intensity effects were important, but breed x rearing intensity interactions were non-significant or inconsistent. Breed and rearing intensity effects were important but their interaction was not for precalving weight gain, calving weight, milk yield, and feed intake and efficiency during lactation. Females of the larger breeds ate more, grew more rapidly, were heavier and produced more energy corrected milk than Danish Jerseys; but breeds did not differ for efficiency of nutrient utilization during lactation or for post-partum weight change patterns. Increased prepubertal daily gains induced by higher-energy diets were associated with lower subsequent milk yield and reduced energy intake during lactation. The RD, DF and RW bulls ate more and grew more rapidly than DJ bulls. Daily energy intake and gain were higher for concentrate-fed than for roughage-fed bulls. Breed and dietary energy level did not interact significantly for these traits. In conclusion, there was little evidence that Danish dairy and dual-purpose cattle breeds differed in the sensitivity of their subsequent milk yield to excessive rates of gain during the rearing period or in response of young bulls to high concentrate versus roughage diets.

ISSN:0906-4702    

DOI:10.1080/09064709509415836

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Response to superovulatory treatment was expressed as number of ova or number of transferable embryos per flush, including or excluding non-responders, and as a categorical trait with only two classes (responders/non-responders). Significant effect of breed was observed for all measures of response, with Red Danish and Danish Red & White having higher values than Danish Jersey and Danish Friesian. Variance/covariance components were estimated for effects of service sire, permanent environment (donor) and additive genotype (donor). Additive genotype did contribute significantly to the phenotypic variance of all quantitative measures of response. Heritabilities of 0.31 ± 0.06 and 0.22 ± 0.07 were found for number of ova and number of transferable embryos, respectively, when non-responders were excluded. If non-responders were included, heritabilities dropped to 0.25 ± 0.06 and 0.15 ± 0.05 for number of ova and number of transferable embryos, respectively. It is argued that systematic use of su-perovulation in cattle breeding programmes might lead to an increase in the frequency of spontaneous multiple births, owing to a genetic change in ovarian sensitivity to gonadotropins.

ISSN:0906-4702    

DOI:10.1080/09064709509415837

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effect of rumen incubation on the true indigestibility of feed protein in the digestive tract (TIFP) was studied for 10 concentrates. Only fish meal and soybean meal showed a constant TIFP independent of rumen incubation time or extent of rumen protein degradation. For the other feedstuffs, TIFP decreased to various degrees at increased ruminal protein degradation. For extracted rapeseed meal, maize gluten meal and guar meal, however, TIFP measured without pre-incubation in the rumen was also satisfactory as a basis for predicting the true digestibility of rumen undegraded feed protein in the intestine (TDRUP) for practical purposes. In contrast, TIFP for predicting TDRUP for peas, rapeseeds, lupin seeds, barley and oats should be determined on feed samples after rumen incubation.

ISSN:0906-4702    

DOI:10.1080/09064709509415838

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Eight bull calves were immunized against somatostatin (SS) conjugated to human serum α-globulin (anti-SS), while another 8 were immunized against human serum α-globulin alone (placebo). All calves were tethered, individually fed concentratesad libitumand slaughtered at an average live weight of 400 kg within each block. Only 5 of the 8 anti-SS calves formed significant amounts of antibodies, with an average binding capacity of 24–34 picomole SS per litre plasma and an antibody affinity (KD) of 0.20 ± 0.04 nM. No difference was found in daily gain (1454 vs. 1378 g, SEM = 71) although voluntary daily energy intake of concentrates was slightly higher (P= 0.17) in anti-SS calves (6.09 vs. 5.54 Scandinavian Feed Units, SEM = 0.27). Feed conversion was also higher (P= 0.08) in. anti-SS calves (4.20 vs. 4.01 SFU/kg gain, SEM = 0.7) and fat content (6.8 vs. 5.4 kg, SEM = 0.3) and amount of perirenal and mesenterial fat (8.45 vs. 6.26 kg, SEM = 0.44) was significantly increased (P< 0.01). Plasma levels of somatotropin and insulin were not altered by immunization. In contrast, insulin-like growth factor-I (IGF-I) was elevated in anti-SS calves following the 4th immunization (301 vs. 259 ng/ml, SEM = 13). The increased plasma IGF-I concentration is most likely a result of increased feed intake. However, a change in IGF-I secretion from liver cells owing to change in concentration of free SS is another possibility. The increased fat deposition also argues against involvement of ST.

ISSN:0906-4702    

DOI:10.1080/09064709509415839

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A review of the effects of immunization against somatostatin in cattle is given. In most experiments (8 out of 9; no information in 2), significant antibody formation was reported in immunized animals but antibody formation may vary between individuals. Only a few have reported data on antibody affinity, but available data indicate that the antibodies formed may act to neutralize SS rather than function as binding proteins. Meta-analysis on weighted group averages showed that anti-SS animals consumed 4.2 ± 1.4% more feed (P= 0.03), had a 11.4 ± 2.3% higher daily gain (P< 0.001) and had a 4.7 ± 2.1% lower feed conversion ratio (P= 0.06), indicating improved feed efficiency. Increased fat deposition has been observed following immunization against SS, but more studies are needed in order to quantify the changes. Immunization does not seem to affect dressing percentage or carcass conformation score. The mode of action of immunization against SS seems to be associated with IGF-I and not GH, but more studies are needed to clarify fully the mechanisms by which immunization modifies performance in cattle.

ISSN:0906-4702    

DOI:10.1080/09064709509415840

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The objective was to examine behavioural and physiological reactions of cows in pens with slatted floors, when pretreatment was tethering in stalls. Ten cows were kept tethered (C), whereas 10 other cows were kept loose in pens with slatted flooring (S). Cow behaviour was observed prior to treatment, and after 4 and 8 weeks, and behaviour in two open-field tests was recorded. Serial plasma concentrations of ACTH and cortisol were measured on day 23 during a 7.5 h period. On d 24, cortisol response was measured in serial samples drawn 0.5 h prior to and for 5 h after intravenous ACTH administration. S-cows showed reduced lying duration and frequency and spent less time exploring and more time immobile in the first test. S-cows showed a slightly increased response to ACTH-injection, otherwise pituitary-adrenal axis reactions did not differ between treatment groups.

ISSN:0906-4702    

DOI:10.1080/09064709509415841

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The effect of early rearing environment and tail docking on behaviour and production of fattening pigs was investigated in 576 cross-bred pigs. Half of the pigs came from four commercial pig units with tethered or otherwise confined sows, 4 weeks' weaning, little space per piglet and no use of straw. The other half of the pigs came from another four commercial units with loose-housed sows, 5-6 weeks' weaning and liberal space and use of straw. Half of the piglets from each of the units were tail docked. At an average weight of 33.5 kg the pigs were transferred to environmentally rich experimental pens where they stayed until slaughter at approx. 100 kg liveweight. On 8 observation days evenly distributed during the fattening period the pigs' use of the straw sections of the experimental pens was recorded as well as oral activities directed towards pen mates, including tail biting. The pigs' use of the pen's straw section declined significantly (p< 0.005) during the fattening period. The rearing environment had a significant effect on nibbling on pen mates (p<0.04) but not on tail biting. The nibbling on pen mates decreased (p< 0.02) while tail biting increased (p< 0.03) during the fattening period. The tail status had no significant effect on either of the two behavioural parameters. Neither rearing environment nor tail status influenced the relative growth rate. Pigs recruited from the “barren” environment showed an almost statistically significant higher incidence of chronic pleuritis (p= 0.069).

ISSN:0906-4702    

DOI:10.1080/09064709509415842

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0906-4702    

DOI:10.1080/09064709509415834

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor