Estimates of genetic and phenotypic parameters for dairy traits in Friesian-Bunaji crossbreds

Genetic and phenotypic parameters for dairy traits were computed using data on Friesian-Bunaji crossbred cows collected over a twenty-three year period (1967-1989) from the dairy herd of the National Animal Production Research Institute Shika, Zaria, Nigeria. Estimated repeatabilities computed from variance components were 0.72 ± 0.06,0.60 ± 0.10,0.73 ± 0.02,0.53 ± 0.24 and 0.56 ± 0.18 for total lactation yield, lactation length, 305-day yield, calving interval and dry period, respectively. Heritability estimates were 0.44 ± 0.07,0.52 ± 0.12,0.30 ± 0.13,0.18 ± 0.02,0.26 ± 0.08 and 0.27 ± 0.10 for total lactation yield, lactation length, 305-day yield, calving interval, dry period and age at first calving,respectively. Genetic and phenotypic correlation coefficients between traits were medium to high, ranging from 0.30 to 0.95. The results of this study showed that the genetic response to selection in Friesian-Bunaji crosses for total lactation yield, 305-day yield and lactation length could be moderately high since the proportion of additive genetic variance was fairly high. Improvement programmes for age at first calving, calving interval and dry period should focus mostly on management, given their low heritability estimates

Phenotypic relationship between body weights of Friesian-Bunaji crossbred heifers and their subsequent milk production

The study reported was conducted to investigate whether fast growing heifers eventually become good milkers in a bid to assist dairy farmers in selecting their replacement stock at an early age. The data analysed consisted of 549 body weight records at birth, 3, 6, 9 and 12 months of age of Friesian-Bunaji crossbred heifers, as well as 840 records on their subsequent lactation length, total lactation yield and estimated 305-day yield collected over a 23-year period (1967-1989). Phenotypic correlations between body weights at fixed ages were all positive and highly significant (P<0.0l), ranging from 0.30 to 0.79. Correlations among milk traits were also positive and highly significant, the range being 0.74 to 0.95. Correlations between body weights and milk traits on the other hand, were very low and non-significant, ranging from 0.01 to 0.14. Equations fitted from simple, multiple and polynomial regressions of body weights on total lactation yield gave very low R2 values. It was therefore concluded that body weights at birth, 3, 6 and 12 months of age have little value in the prediction of future milk yield of Friesian-Bunaji heifers

Effects of alirocumab on types of myocardial infarction: insights from the ODYSSEY OUTCOMES trial

Aims  The third Universal Definition of Myocardial Infarction (MI) Task Force classified MIs into five types: Type 1, spontaneous; Type 2, related to oxygen supply/demand imbalance; Type 3, fatal without ascertainment of cardiac biomarkers; Type 4, related to percutaneous coronary intervention; and Type 5, related to coronary artery bypass surgery. Low-density lipoprotein cholesterol (LDL-C) reduction with statins and proprotein convertase subtilisin–kexin Type 9 (PCSK9) inhibitors reduces risk of MI, but less is known about effects on types of MI. ODYSSEY OUTCOMES compared the PCSK9 inhibitor alirocumab with placebo in 18 924 patients with recent acute coronary syndrome (ACS) and elevated LDL-C (≥1.8 mmol/L) despite intensive statin therapy. In a pre-specified analysis, we assessed the effects of alirocumab on types of MI. Methods and results  Median follow-up was 2.8 years. Myocardial infarction types were prospectively adjudicated and classified. Of 1860 total MIs, 1223 (65.8%) were adjudicated as Type 1, 386 (20.8%) as Type 2, and 244 (13.1%) as Type 4. Few events were Type 3 (n = 2) or Type 5 (n = 5). Alirocumab reduced first MIs [hazard ratio (HR) 0.85, 95% confidence interval (CI) 0.77–0.95; P = 0.003], with reductions in both Type 1 (HR 0.87, 95% CI 0.77–0.99; P = 0.032) and Type 2 (0.77, 0.61–0.97; P = 0.025), but not Type 4 MI. Conclusion  After ACS, alirocumab added to intensive statin therapy favourably impacted on Type 1 and 2 MIs. The data indicate for the first time that a lipid-lowering therapy can attenuate the risk of Type 2 MI. Low-density lipoprotein cholesterol reduction below levels achievable with statins is an effective preventive strategy for both MI types.For complete list of authors see http://dx.doi.org/10.1093/eurheartj/ehz299</p

Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≥3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≥100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≥3 years, if baseline LDL-C is ≥100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

A note on development of white egg layer breeding stock from commercial day old chicks.

An attempt has been made to show that white egg layer can be developed from commercial day old chicks. This is a comfortable way to have a gene pool and pure lines. At this stage of Nigeria's development, we should not be bothered about the luxury of producing brown eggs. This is because white eggs are more economical to produce. Brown egg layers consume more feed per egg produced, while in most cases, white egg layers lay more eggs. Furthermore, the development of the brown egg layer will involve more expenses than the white egg layer. This is so because the starting point for such a development will be the brown egg layer grandparent stock, which is more e.xpensive than the commercial white egg layer.Key words: Breeding of White egg layer

Evaluation of pure and crossbred parent stock pullets: 1. Egg weight, body weight and sexual maturity

The relationships between egg weight, body weight and sexual maturity and their inheritance were  studied in the Fl of two grandparent strains or laying birds. Each strain had two lines. Data used for analyses comprised bodyweight at firstegg,30weeks and 40 weeks of age (BFE, 830 and B40); weight of first egg (WFE), weight of egg at 30 weeks and 40 weeks (W30, W40) and age or birds at first egg (AFE). Phenotypic correlations between AFE and BFE, AFE and WFE and between WFE and BFE were 0.45 and 0.40; 0.96 and 0.11, 0.65 and 0.85 for male and female lines respectively. While AFE generally showed additive inheritance which was sire  influenced, BFE and WFE were line dependent. The crossbred groups however, appeared to be at advantage over the purebreds in respect of these three traits.Key words: Parent stock, pullets, egg weight, body weight, sexuaJ maturity

Breed effect and non-genetic factors affecting growth performance of sheep in a semi-arid region of Nigeria

Objective: This study was conducted to investigate the effects of breed and some non-genetic factors on growth performance of Balami and Uda sheep in a semi-arid region of Nigeria.Methodology and results: Data on birth weight (BWT), 90-day weaning weight (90-DWWT), 6-month weight (6-MWT), 9-month weight (9-MWT) and yearling weight (Y-WT) of 595 lambs (306 Balami and 209 Uda) born in the Sheep Meat Project of the Federal Livestock Department (FLD), Katsina, between 1996 and 1998 inclusive were collected and used for this study. Pre and post weaning weight gains were also estimated on each lamb. Data was subjected to analysis of variance using the generalized linear model (GLM) procedure of SAS to determine the effects of breed, parity, sex, type of birth, season of birth and year of birth on the growth of lambs. Breed and sex significantly (P&lt;0.05) affected body weights at all ages. Pre and post-weaning growth rates were significantly (P&lt;0.05) affected by all the factors examined except parity of dam and year of birth. Significantly low to moderate phenotypic correlations were observed between the growth traits studied.Conclusion and application of findings: Most of the non-genetic factors have been shown to be important sources of variation in the growth performance of sheep. Therefore, effects of environmental factors need to be corrected for if mixed model approaches such as the Best Linear Unbiased Prediction (BLUP) values are to be used for breeding value evaluation in Balami and Uda lambs.Key words: Sheep, Balami, Uda, Pre and Post weaning growth, Sex, Parity

A comparative sstudy of the physical and chemical characteristics of guinea fowl and domestic chicken eggs

No Abstract