Feed intake, growth and blood parameters were studied over 3 years, in 2,300 chickens started either during the cool, dry season or the hot, dry season. From day old to 4 weeks, fed was more efficiently used for growth during the hot, dry season than for the cool, dry season. Using Haemoglobin and Haematocrit as criteria, and on supplementing a practical type ration with copper and iron, it was observed that climatic stress, as distinct from mineral deficiency, plays an important role in the brooding of exotic chickens in the tropics. The importance of this in relation to housing and timing of brooding the chickens by commercial producers was highlighted. 相似文献
Thirty-two water buffalo (Bubalus bubalis) calves aged 6?C10?months were used to evaluate serological responses to Brucella abortus strain RB51 (RB51) vaccination in a dose?Cresponse study and to compare the use of two selective media for the isolation of RB51. The animals were randomly divided into three treatment groups. Groups I?CIII received the recommended vaccine dose (RD) twice 4?weeks apart, RD twice 18?weeks apart and saline once, respectively. Lymph nodes were excised from the three groups and subjected to bacteriological examination to determine the frequency of detection of RB51. Pre- and post-vaccination blood samples were collected and tested for B. abortus antibodies using the buffered plate agglutination test (BPAT), complement fixation test (CFT), and dot-blot assay. Sera taken at all post-inoculation weeks (PIW) were negative for field strain B. abortus using the BPAT. Antibody responses to RB51 were demonstrated in all vaccinates but not in controls by CFT and dot-blot assay from 1 PIW up to 16?weeks following booster vaccination. The agreement for both assays was 80.7% and there was a linear interdependence with a Pearson??s correlation coefficient value of 0.578. The frequency of isolation of RB51 from the two selective media used was not significantly different (P?>?0.05). 相似文献
The occurrence of African swine fever (ASF) DNA in slaughtered pigs in the major pig producing areas of Plateau state over
a 2-year period was investigated. Three hundred fifty-nine pig tissue samples from five local government councils (LGCs) were
analyzed by clinical signs (C/S), postmortem (PM) lesions and polymerase chain reaction (PCR). The results of diagnosis made
by C/S and PM were compared to results obtained by PCR. Out of the 359 abattoir samples, 13 (3.62%) were positive by examination
of C/S and PM lesions while 346 (96.38%) were negative. Jos-north LGC had the highest occurrence of PCR positive samples (31
samples); Panyam in Mangu LGC had no positive result. PCR analysis identified 53 positive samples (14.76%); more than 40 were
identified on the field. Of the samples, 306 were PCR negative, thus giving a true ASF status of pigs in Plateau state. Analysis
of the results, variables involved in the ASF spread and predictable effects of such findings in the pig industry in Plateau
state and Nigeria as a whole is discussed. 相似文献
1. Broiler chicks fed on a semi‐purified diet containing 230 g crude protein and less than 5 mg pyridoxine/kg had poor growth rates and high mortality.
2. When a milled, unsupplemented diet based on rice and groundnut was fed, food utilisation, carcass fat content and serum aspartate amino transferase [EG 2.6.1.1] activity indicated the need for supplementation with at least 3 mg pyridoxine, or a total concentration of 8.8 mg/kg diet.
3. With a maize‐groundnut diet body‐weight gain, food intake and tissue aspartate aminotransferase activities suggested that dietary supplementation with pyridoxine was unnecessary, but food utilisation indicated a need for supplementation with 3 mg or a total intake of 9 mg pyridoxine/ kg diet.
4. A practical broiler chick starter diet was used to show that the total concentration of pyridoxine should be at least 7.2 mg/kg when maize‐groundnut diets are fed. 相似文献
The effect of high levels of microbial phytase supplementation in diets for growing pigs was studied in a 2‐week performance and nutrient digestibility trial involving 28 growing pigs weighing 16.4 ± 1.06 (mean ± SD) kg. Seven corn‐barley‐soybean meal‐based diets consisting of a positive control (PC) formulated to meet or exceed NRC nutrient requirements; a negative control (NC) with non‐phytate P reduced by 0.1% unit from NRC requirement and fed without or with 500 or 1000 U/kg; a doubled negative control (DNC) with no added inorganic P and fed without or with 2000 or 4000 U/kg. Chromic oxide was added as an indigestible marker and all diets were fed as mash. Pigs fed the PC diet had a higher P digestibility compared with those fed the NC (P < 0.02) and the DNC (P < 0.001) diets. Supplementing the NC diet with pyhtase tended to improve P digestibility (P < 0.10). However, addition of phytase to the DNC diet resulted in linear (P < 0.001) and quadratic (P < 0.03) increases in P digestibility with an overall improvement of 8% and 121% at 4000 phytase U/kg of diet, respectively, compared with the PC and DNC diets. Apparent total tract digestibility of N, OM and DM were higher (P < 0.05) in the PC diet compared with the DNC diet, but not the NC diet (P < 0.10). No effect of phytase addition to NC was observed on Ca, N, DM and OM digestibility. Phytase addition to the DNC diet resulted in a linear increase (P < 0.05) in N, DM and OM digestibility but not Ca. Increasing the levels of phytase supplementation in the NC and the DNC diets linearly decreased fecal P (P < 0.05) content by 45 and 42%, respectively. Adding phytase at 1000 or 4000 U/kg increased P retention (P < 0.05) by 14.3 or 15.6% units, respectively, compared with the PC diet. Urinary P excretion was higher in the group fed the PC diet compared with those fed the NC and DNC diets (P < 0.05). The results of this study show that complete removal of inorganic P from growing pig diets coupled with phytase supplementation improves digestibility and retention of P and N, thus reducing manure P excretion without any negative effect on pig performance. 相似文献
A study was conducted to determine the seroprevalence of leptospirosis and infecting serovars across livestock (cattle, sheep,
goats, and pigs) in Trinidad using the microscopic agglutination test with an international panel of 23 serovars. Of a total
of 590 cattle tested, 21.5% were seropositive with agglutinations to 13 of the 23 antigens used in the panel. Icterohaemorrhagiae
(9.3%), Sejroe (4.1%), Ballum (4.1%), and Autumnalis (1.9%) were the predominant serogroups detected in the cattle sampled
(n = 590). Of 222 sheep tested, 5.0% were seropositive with agglutinations to five serovars belonging to two serogroups. These
serogroups were Autumnalis at 2.7%, and Icterohaemorrhagiae at 2.3% of all sheep tested (n = 222). Of a total of 180 goats tested, 3.3% were seropositive, all agglutinating to the Icterohaemorrhagiae serogroup, 1.7%
to serovar Copenhageni, 1.1% to serovar Mankarso, and 0.6% to serovar Icterohaemorrhagiae. Among pigs (n = 200), 5.0% were seropositive for five serovars belonging to three serogroups. These serogroups were Icterohaemorrhagiae
at 2.5%, Australis at 2%, and Ballum at 0.5%. Overall, age and sex of animals were not significantly associated with leptospirosis
with the exception of cattle where age was a significant factor for seropositivity. It was concluded that for livestock, leptospirosis
may be an important zoonotic and economic disease, particularly in the case of cattle. It is imperative that the impact of
leptospirosis on abortion, stillbirths, and decreased milk production in livestock in the country be assessed. 相似文献
Identification of hybrids for commercialization is crucial for sustainable maize production in sub-Saharan Africa (SSA). One hundred and ninety test crosses, 10 tester × tester crosses + 10 hybrid checks were evaluated across 11 environments, 2017 to 2019. Inheritance of grain yield under Striga infestation, optimal and across environments was influenced by additive genetic action, but there was greater influence of nonadditive gene action under drought stress conditions. Nine, seven and two inbreds had significant and positive general combining ability (GCA) effects for grain yield under Striga-infested, optimal and drought stress environments, respectively, and would contribute high grain yield to their progenies. Heterotic grouping methods based on specific and GCA, GCA effects of multiple traits and DArTseq markers classified the inbreds into five, three and two heterotic groups, respectively, across research conditions. The DArTseq markers method that classified the inbred lines into two major heterotic groups and was one of the most efficient methods should be adopted for practical purposes in maize breeding programmes in SSA. Hybrids TZEI 7 × TZdEI 352, TZEI 1238 × TZEI 7 and TZEI 1252 × TZEI 7 had outstanding grain yield under contrasting environments and should be tested on-farm for commercialization in SSA. 相似文献
The cover image is based on Research Article Development of enzymes for robust aryloxyphenoxypropionate and synthetic auxin herbicide tolerance traits in maize and soybean crops by Clayton T Larue et al., DOI: 10.1002/ps.5393 X‐ray crystallography was used to solve the structure of FT enzymes (FT_T shown in both ribbons and space fill views).
The aim of the study was to evaluate the effects of varying concentrations of ethylenediaminetetraacetic acid (EDTA) on blood
samples from White Fulani breed of cattle and West African Dwarf goat from Nigeria. Sample sizes of 20 animals were used for
both species. Different concentrations of EDTA (2, 4, 8 and 16 mg/ml) were used. The packed cell volume (PCV), red blood cell
(RBC) and haemoglobin (Hb) concentration of blood samples collected from White Fulani breed of cattle and West African Dwarf
goat into bottles containing 16 mg/ml of EDTA were significantly lower (P < 0.05) than those samples collected from the same animals into bottle containing 2 mg/ml (control). Similarly, the PCV,
RBC and Hb values of the West African Dwarf goats in bottles containing 8 mg/ml of EDTA were significantly lower than those
of the samples in the control (2 mg/ml). This study has shown that high concentration of EDTA as an anticoagulant can lead
to a false erythrocytic index especially the PCV. In collecting blood samples for evaluation of haematological parameters,
therefore, the blood volume/anticoagulant ratio must be strictly adhered to prevent error in the evaluated parameters in cattle
and goats. Taken together, there is tendency for haemolytic anaemia to occur in blood sampled at higher concentration of anticoagulants
in West African Dwarf goat than in White Fulani breed of cattle. 相似文献
The water buffalo is an important domestic animal worldwide, and the local Buffalypso variety was developed in Trinidad to
have improved beef qualities. Brucellosis was diagnosed in Trinidad and Tobago during 1998 in both cattle and domestic water
buffalo (Bubalus bubalis) populations. Brucellosis in the latter species is caused by infection with Brucella abortus, similar to bovine brucellosis. Control of brucellosis is of paramount importance to preservation of the genetic diversity
of these animals in Trinidad, and this has been complicated by differences in the epidemiology of water buffalo and bovine
brucellosis. Some diagnostic tests do not have comparable accuracy between the two species, and the RB51 vaccine does not
adequately protect against infection in water buffalo. The water buffalo in Trinidad may also be more resistant to infection
than cattle. Development of effective vaccination protocols is key to brucellosis control in Buffalypso in Trinidad, and prohibitions
on import of virulent B. abortus strains for vaccine efficacy studies has impeded progress in this area. These Trinidadian strains are of variable virulence;
some might be effective for challenge in vaccine efficacy studies, while other, of lower virulence, may be vaccine candidates
for use in water buffalo. 相似文献
