This study covered 737 controlled first calving Simmental cows with, lactations concluded within one year. All first calving animals were on the farms of individual farmers in the municipalities of Kragujevac and Mladenovac. The research included the influence of bull sires, year and season of calving on milk yield and fertility. Least squares method was used to determine the average duration of lactation of 323.74 days. For a period of 305 days, heifers produced 3701.67 kg of milk, or 3644.58 kg of 4% FCM. The average production of milk fat was 144.26 kg and milk fat content was 3.88%. The interval from calving to first insemination lasted in average 124.19 days, and the animals were first calved at the age of 789.95 days. The bull sires had a highly significant effect (P<0.01) on the duration of lactation, milk yield and 4% FCM, milk fat yield and content and age of cows at first calving. The duration of service period was not under significant effect (P>0.05) of bull sires. Year of calving had a significant effect (P<0.01) on the duration of lactation, production of milk, milk fat and 4% FCM. Milk fat content, service period and age at first calving did not show significant variation due to the impact of different years of calving (P>0.05). Season of calving of cows demonstrated highly significant effect (P<0.01) on the production of milk and 4% FCM, and significant (P>0.05) on the production of milk fat, however it had no effect (P>0.05) on the milk fat content, duration of lactation and service period and age at calving.
Ammonia production in commercial poultry sheds poses a problem for farmers as high levels can affect animal's respiratory health, resulting in hock and foot pad lesions and thereby affecting performance. A study was conducted to evaluate the suitability of whole, chopped and dried Yucca schidigera (De-Odorase™, Alltech Inc, USA) to reduce ammonia excretion from broilers and investigate the impact on broiler performance. Nine hundred and two, one-day-old Cobb broilers were randomly assigned to one of two diets, without (control) or supplemented with 500 g/t De-Odorase™. Birds fed the treatment diet had significantly higher body weight (P < 0.05) at 42 d and improved FCR (P < 0.05). Significant reductions in ammonia from litter were reported at 37 and 42 days old (P < 0.05 and P < 0.1, respectively). No significant differences were seen in foot pad, gait score, feather score or carcass data; although the birds fed De-Odorase™ had consistent numerical improvements in these parameters. The results of this study suggest that feeding whole, chopped and dried Yucca schidigera as a functional ingredient in the diet can be part of an ammonia management programme to improve broiler welfare and zootechnical performance.
Our investigations were conducted in order to determine the influence of mannan-oligosaccharide (MOS) based prebiotics and polysaccharide microelement complexes on the performance and immune response of Arbor Acre broiler chickens. Total of 186 chickens was included in the study which lasted 42 days. Birds were fed ad libitum three different complete food mixtures (from days 1- 21, 21 - 35 and 35-42) according to the standard fattening procedure. Mixtures for chickens from the first group were supplemented with mannanoligosaccharide based prebiotics and for the birds from the second group with polysaccharide microelement (Fe, Cu, ZN and Mn) complexes. Broilers in the control group had daily weight gain of 49.1 g, daily food consumption of 115.5 g and a feed : gain ratio 2.35. In the group of broilers feed mixtures supplemented with mannan-oligosaccharides, the daily weight gain was higher (+ 14.95%), daily food consumption was lower (- 2.67) and feed : gain ratio was smaller (-15.32%) when compared to the control group. In the group of broilers fed mixtures with polysaccharide microelement complexes, the daily weight gain was also higher (+ 11.43%), daily food consumption was lower (- 4.28) and feed: gain ratio was smaller (-14.0%) when compared to the control group. Following revaccination against NCD, broilers fed MOS based prebiotics had significantly higher titers of antibodies than observed in the other two groups. The highest degree of cutaneous hypersensitivity to PHA was recorded in the group of broilers fed mixtures with polysaccharide microelement complexes
The study of the production capacities of cattleaimed at increase of the capacity of cattle to produce milk, milk fat and calves, greatly depends on pehotypic anf genetic variability, heritability and correlation between preferable traits, as well as level of production in the population. Objective of the study was to calculate the variability, phenotypic and genetic correlation of milk and type traits by applying the method of linear scoring of cows in the nucleus herd of Holstein-Friesian bull dams and also to determine their significance in cattle selection. For all studied traits, main variation-statistical parameters were calculated by applying method of least squares: arithmetic mean, standard deviation, variation coefficient, standard error and variation interval. Negative phenotypic correlations between production of milk and type traits ranged from-0.12 (rear leg set, side view) to-0.01 (rump height and body depth) and positive from 0.03 (rear teat placement) to 0.23 (suspensory ligament). Phenotypic correlations between milk fat percentage and type traits varied in the range from-0.08 (fore teat placement) to 0.14 (rump height). Negative genetic correlations between milk production and type traits ranged from-0.11 (rear udder height) to-0.01 (rump width and dairy form), and positive from 0.03 (rear legs set, rear view) to 0.23 (suspensory ligament). Genetic correlations between the percentage of milk fat and type traits ranged from-0.15 (pelvic position) to 0.18 (rump height). Information about phenotypic and genetic correlations between milk and type traits can be of multiple significance in cow selection since it offers possibility to select heads of cattle for multiple traits at the same time.
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