Genetic analysis of persistency in HF crossbred cattle at an organized farm of northern India

The present study was undertaken to estimate effect of various genetic and non-genetic factors on persistency of milk production and to identify the most appropriate persistency method that fits best in our environment. In the present study, effects of different non-genetic factors, viz. year, season, days to attain peak yield, and genetic group based on the level of exotic inheritance on persistency of milk yield in crossbred cattle were studied. Data comprised of 686 first lactation daily milk yield records of crossbred cattle that were maintained at GADVASU dairy farm over a period of 25 years from 1991 to 2015 were utilized to calculate persistency coefficients by four methods, viz., Ludwick and Peterson method (P1), Mahadevan method (P2), ratio method (P3), and Prasad et al. method (P4). Overall least squares means for persistency by Ludwick and Peterson method (P1), Mahadevan method (P2), ratio method (P3), and Prasad et al. method (P4) were 0.896?±?0.096, 1.385?±?0.224, 187.207?±?26.398, and 0.621?±?0.098, respectively. Effect of sires was significant (P?<?0.05) on P2 and P4 methods. Effect of genetic group on all four methods was non-significant. Period of calving had significant (P?<?0.01) effect on persistency of milk yield (P2, P3, and P4 methods). Effect of season of calving on persistency of milk yield was found to be significant in all estimates obtained by the four methods. Summer and autumn calvers were most persistent whereas spring and winter calvers were least persistent for (P2, P3, and P4 methods). Persistency of milk yield was significantly (P?<?0.05) affected by days to attain peak yield in P1 and P2 methods. Maximum persistency was obtained in animals attaining peak at 41–57 days of lactation and minimum in <?41 days for Mahadevan method and ratio method. The highest heritability of persistency and minimum value of standard error was estimated as 0.275?±?0.11 for the Mahadevan method followed by the Prasad method (0.197?±?0.10) by half sib correlation method. The maximum coefficient of variation which indicates available variability was estimated as 20.788% for persistency by the Mahadevan method followed by 18.969% for the Prasad method. The highest correlation was also observed between P1 and P3 methods by Spearman’s and Pearson’s correlation for least squares breeding value of the sires. On the basis of heritability, standard error of heritability, and coefficient of variation, it can be concluded that the Mahadevan method followed by the Prasad method suits best to our environment for animals in first lactation as well as they can be utilized for effective selection for higher persistency in crossbred animals of Punjab.     

Development of sustainable performance index based on production,reproduction, health and longevity for genetic improvement of Sahiwal cattle

An attempt was made for the first time in India to develop the performance indices for quantifying the relative emphasis to be given to production, reproduction, health and longevity traits for selection and genetic improvement of Sahiwal cattle in a sustainable manner. The study was conducted using information related to various production, reproduction, health and longevity traits spread over a period of 29 years in Sahiwal cattle. Using income and expenditure method, the relative economic values for 305 days milk yield (305DMY), average daily milk yield (ADMY), calving to first insemination interval (CFI), days open (DO) and longevity (LNG) were estimated as 1, 1, −6.62, −6.62 and 5.96 in Sahiwal cattle. A total of three performance indices were constructed using three-trait combination, that is production, reproduction and longevity before and after excluding the days suffered by the animals. Correlation between the aggregate genotype and index (R_IH) was computed to determine the accuracy of each performance index, and based on highest R_IH value, best performance index was identified for selection of Sahiwal cattle. Developed indices were further assessed for robustness by increasing the relative economic values of the traits by 25% and 50%. The performance index (305DMY, DO and LNG) was found to be the best index before as well as after excluding days suffered by the animals, but in later case emphasis to be given to different traits was found to be more balanced. The best index indicated that about 47, 42 and 11% relative emphasis to be assigned to 305 days milk yield, days open and longevity for selection of Sahiwal animals for sustainable genetic improvement.     

Performance of Lipaphis erysimi (Homoptera: Aphididae) on different Brassica species in a tropical environment

A 2-year study on the preference and performance of Lipaphis erysimi on different Brassica species in the field and under greenhouse conditions revealed that rapeseed (B. campestris var. BSH-1, B. campestris var. YSPB-9) and mustard (B. juncea RH-30) were better hosts for this aphid than other Brassica species (B. napus, B. nigra, Eruca sativa, B. carinata). On the first group of plants, the rate of nymphal development, longevity and fecundity of this pest were significantly less than on the second group of plants. Development was significantly prolonged when the aphid was reared on second group of plants.     

Breast-feeding initiation and determinants of exclusive breast-feeding - a questionnaire survey in an urban population of western Nepal

OBJECTIVE: To assess rates of initiation of breast-feeding and exclusive breast-feeding within 2 months after delivery and to determine the factors influencing exclusive breast-feeding. DESIGN: A health worker-administered questionnaire survey was carried out during the time period 1 August-30 September 2005. SETTING: Immunisation clinics of Pokhara, a submetropolitan city in western Nepal. SUBJECTS: Three hundred and eighty-five mothers who had delivered a child within the previous 2 months. RESULTS: The rates of initiation within 1 h and within 24 h of delivery were 72.7 and 84.4%, respectively. Within 2 months after delivery, exclusive breast-feeding was practised by 82.3% of the mothers. Breast milk/colostrum was given as the first feed to 332 (86.2%) babies but 17.2% of them were either given expressed breast milk or were put to the breast of another lactating mother. Pre-lacteal feeds were given to 14% of the babies. The common pre-lacteal feeds given were formula feeds (6.2%), sugar water (5.9%) and cow's milk (2.8%). Complementary feeds were introduced by 12.7% of the mothers. By logistic regression analysis, friends' feeding practices, type of delivery and baby's first feed were the factors influencing exclusive breast-feeding practice of the mothers. CONCLUSIONS: Despite the higher rates of initiation and exclusive breast-feeding, practices such as pre-lacteal feeds and premature introduction of complementary feeds are of great concern in this urban population. There is a need for promotion of good breast-feeding practices among expectant mothers and also the community, especially the families, taking into account the local traditions and customs.     

Growth Performance,Carcass Yield and Meat Quality of Korean Native Duck

This study was carried out to investigate the growth performance, carcass yield and meat quality of large-type Korean native ducks （KND）. A total of 420 day-old ducklings were divided into four treatments （seven replicates/treatment, 15 birds/replicate） by strains （A and B） and gender （male and female） in a 2 × 2 factorial arrangement under complete randomized design. The body weight （BW） of female KND was higher at week 2 and for male it was higher in week 8 （P 〈 0.05）. BW gain, feed intake and feed conversion ratio of male KND were higher than those of female KND （P 〈 0.05） during week 0 to week 8. The carcass yield of both strains increased from 6 weeks to 8 weeks （P 〈 0.05）. The breast meat ratio was the highest at week 8 whereas the leg meat ratio was the highest at 6 weeks of age in both strains （P 〈 0.01）. Lightness （L＊）, yellowness （b＊） and juiciness of meat were the highest at 6 weeks （P 〈 0.05）. Moisture, ash and fat contents of meat were the highest at 7 weeks （P 〈 0.05） and protein content was the highest at 8 weeks （P 〈 0.01）. These results may provide the basic data on growth performance and meat quality of large-type KND, which can be used for genetic improvements and rearing at commercial scale.     

Can irrigation be sustainable?

Globally, about 10 Mha of agricultural land is lost annually due to salinisation, of which about 1.5 Mha is in irrigated areas. While some climate and management aspects are common to semi-arid regions, the detailed mechanisms and options to secure ecological sustainability and economic viability may vary considerably from case to case. This paper applies a whole of system-water balance to compare irrigation in three semi-arid regions suffering from similar sustainability issues: Rechna Doab (RD), Pakistan; the Liuyuankou irrigation system (LIS), China; and Murrumbidgee irrigation area (MIA), Australia. Soil salinity, lack of adequate water resources and groundwater management are major issues in these areas. The MIA and LIS irrigation systems also suffer from soil salinity and low water-use efficiency issues. These similarities occur in spite of very different climatic and underlying hydrogeological conditions. The key data used to compare these different regions are climate and soils, available water resources and their use, as well as components of the water balance. In addition, the history of water resource development in these areas is examined to understand how salinity problems emerge in semi-arid regions and the consequences for production. Based on the efficiency parameters and the definitions of sustainability, approaches are explored to solve common environmental problems while maintaining economic viability and environmental sustainability for irrigation systems.     

Heritability, and Intra- and Inter-Generation Associations Between Tuber Yield and its Components in Potato (Solanum tuberosum L.)

The relative importance of the components of tuber yield in selection in early generations of a potato-breeding programme was studied. In seedling generation the number of tubers were more important than average tuber weight, whereas in clonal generations the average tuber weight was more important. Correlation coefficients between number of tubers and tuber yield varied from generation to generation whereas those of average tuber weight and tuber yield were more or less constant. Unlike the number of tubers, the average tuber weight of a genotype in a generation influenced its tuber yield in subsequent generations. The average tuber weight had higher heritability than the number of tubers and tuber yield.     

Photosynthesis and Dry Matter Production in T. monococcum and T. aestivum Wheat in Response to Ear Removal

The photosynthesis, shoot formation, leaf area development and dry matter production were examined in control and de-eared plants of T. monococcum var. G 1372and T. aestivum var. Sonalika. The removal of ears decreased the diurnal maintenance of photosynthesis and consequently, the dry matter production in Sonalika but not in G 1372. There was a considerable growth of alternative sinks such as shoots and roots when ear sinks were removed. This alternative sink capacity of de-eared plants seemed to have compensated for limited sink demand of ears in G 1372but could not entirely compensate for the more efficient grain sink in Sonalika. The diploid wheat produced more dry matter than the hexaploid wheat in the pre-ear emergence period and less in the post-ear emergence period. In the preear emergence period, the difference in dry matter appeared to be mostly because of the difference in duration to ear emergence. During the post-ear emergence period, the lower dry matter in G 1372seemed to be owing to a rapid decrease in photosynthesis rate after anthesis because of the lower sink capacity of its grains.