Magdalena Szyndler-Nędza, Marian Różycki, Robert Eckert, Aurelia Mucha, Mirosław Koska and Tadeusz Szulc
Normal development of piglets is determined principally by the milking ability of the sows. This study attempted to determine the relationships between sow’s milk quality and rearing performance of the piglets. The experiment was carried out under uniform conditions, with standard feeding of the sows and a similar number of piglets per litter. The study accounted for 109 lactations of second- and third-parity Polish Large White (PLW ) sows and 123 lactations of second- and third-parity Polish Landrace (PL) sows. Colostrum and milk were collected from the sows at 1, 7, 14 and 21 days of lactation and analysed for solids, crude protein, fat, lactose and somatic cell count (SCC). Rearing performance of second- and third-litter piglets was determined based on the number and weight of piglets at birth and at 7, 14 and 21 days of age. The coefficients of correlation, estimated between basic composition of milk and rearing performance of the piglets over subsequent weeks of lactation were low and exceeded r = 0.200 only for some traits. The experiment showed that a higher content of basic milk components, in particular protein, may be one of the factors contributing to an increase in weight gain of piglets during a 21-day lactation. Milk fat content may be of significance for rearing performance of piglets only during their first week of life. Rearing performance of the piglets is unrelated to udder health expressed as milk SCC.
Franciszek Brzóska, Bogdan Śliwiński and Olga Michalik-Rutkowska
An experiment with 608 broiler chickens was conducted to investigate the effect of dietary acidifier level on body weight, feed consumption and conversion, mortality, dressing percentage, postmortem carcass traits, tissue composition of breast and leg muscles, and plasma chemical parameters. Feeding the acidifier to chickens at 3, 6 and 9 g/kg of the diet reduced the pH of starter and grower diets from 6.90 to 5.89, and from 6.28 to 5.73, respectively. Compared to the control group, dietary acidification significantly increased body weight of chickens by 6.2, 8.2 and 8.2% at 21 days of age, and by 2.7, 3.6 and 3.7% at 42 days of age, respectively (P<0.01). Mortality decreased from 2.58% in the control group to 0.00-0.59% in the experimental groups (P<0.01). Acidification of the diets increased EEI-index from 327 (control group) to 348 points in the experimental group supplemented with 9% (9 g/kg) acidifier, but had no significant effect on feed consumption and feed conversion ratio among treatments. The relative weight of breast and leg muscles, gizzard, liver and carcass depot fat was not affected by dietary treatments. Breast muscles represented 27.7% (control group) and 27.9% (experimental groups) of the carcass weight. Leg muscles made up 21.5% and 20.7% of the carcass weight, respectively. There were no significant differences in chemical composition of breast and leg muscles, including dry matter, protein and fat content. No significant differences between the control and experimental chickens were noted for determined blood plasma constituents, glucose, total protein, triglycerides, total cholesterol and high density lipoprotein. The results suggested that organic acid acidifier used in this experiment at the rates of 3 to 9 g/kg diet has a growth enhancing and mortality reducing effect in broiler chickens, with no significant influence on carcass yield, proportion of individual carcass parts and blood plasma constituents. It seems that the amount of 6g of the applied acidifier per kilogram of feed may be recommended as the optimum dietary level if protein in the diet does not exceed 200-230 g crude protein per kilogram of diet.