Effects of rolling whole linted cottonseed and whole acid-delinted cottonseed on whole seed passage and digestibility were determined using 24 lactating Holstein cows. Whole seed passage averaged .74% in all cows fed whole linted seed during the standardization period and .45% in 6 cows fed whole linted seed during a comparison period, contrasted to 11.3% in 6 cows fed acid-delinted seed. Digestibility of ether extract was less in the 6 cows fed whole acid-delinted cottonseed. No advantage was for rolling whole linted cottonseed before feeding, but rolling was beneficial for whole acid-delinted cottonseed. Individual consumption of whole linted cottonseed by 18 nonpregnant, dry Holstein cows varied from .04 to 5.05 kg/day when two-choice options were given for cottonseed versus chopped coastal bermudagrass hay or corn silage, or a complete ration of 75% corn silage and 25% concentrate. No indication of gossypol toxicity was seen, but the large variation in each choice situation suggests it is desirable to blend cottonseed with other ingredients to ensure more uniform consumption.
In Experiment 1, 27 lactating cows were fed complete rations ad libitum of 0, 15, and 30% whole cottonseed to examine the effects on intake, digestibility, blood gases, and blood metabolites. Dry matter intake declined linearly with increased cottonseed, but because of greater energy density, calculated net energy for lactation intake was not depressed significantly. Ether extract, crude protein, and calcium digestibility increased with cottonseed in the diet. Respiration rates declined with dry matter intake and increased cottonseed feeding; some blood gases were influenced by cottonseed feeding but not in a detrimental way. No data among 13 blood metabolites indicated effects of gossypol toxicity with 30% whole cottonseed in the diet. In Experiment 2, 24 dry, nonpregnant Holstein cows were offered complete rations ad libitum of 15, 35, and 55% whole cottonseed to measure responses in intake, respiration rates, and blood metabolites. The highest cottonseed diet significantly depressed intake of both dry matter and calculated net energy for lactation. Maximum dry matter from cottonseed eaten by an individual was 8.4 kg/d (average for 1 wk). Respiration rates declined parallel to intake. No evidence for gossypol toxicity was seen among data of 11 metabolites in blood.
Four mature nonlactating Holstein heifers fitted with ruminal and duodenal cannulae were used to investigate in vivo effects of niacin and whole cottonseed. Each heifer was assigned randomly to a treatment in a 2 X 2 factorial arrangement of treatment sequences within a 4 X 4 Latin square design. Heifers were fed isonitrogenous complete mixed rations individually twice daily. Diets contained corn-soybean meal concentrate, corn silage, chopped coastal bermudagrass hay, plus 1) 0% niacin and 0% whole cottonseed, 2) 0% niacin and 15% whole cottonseed, 3) .07% niacin and 0% whole cottonseed, or 4) .07% niacin and 15% whole cottonseed. Dry matter consumption, ruminal pH, ruminal ammonia and VFA concentrations, microbial N production, and DM and ADF digestion were not affected by treatment. Numbers of ruminal protozoa and RNA concentrations were reduced with whole cottonseed feeding and increased by addition of niacin. Whole cottonseed increased molar percentages of acetate while depressing propionate. Niacin supplementation resulted in greater digestion of both CP and NDF. Ether extract digestibility was highest in heifers fed whole cottonseed. Fiber digestion was not affected by whole cottonseed feeding.
Effects of retained fetal membranes on subsequent productive and reproductive performance were measured in a single Florida Holstein dairy herd (n = 216 retained fetal membranes and 208 normal cases). Mean performance was peak daily milk yield, 31.9 kg; 305-d milk yield, 6317 kg; days to first service, 60; days open, 115; and services per conception, 2.3. Yield was unaffected by retained fetal membranes; however, retention resulted in an increase of 4 d to first service, 19 d open, and .2 services per conception. Detrimental effects of parturitions in hot weather (July through September) compared with cool (December through February) were peak daily milk yield, 5.5 kg; 305-d milk yield, 512 kg; days to first service, 3; days open 39; and services per conception, .9. Interactions could not be detected between diagnosis (retained or normal) and season for any response. Sex of calf effects could not be detected for any response. Continued research to reduce occurrence of retained fetal membranes or to obviate its effects should lead to improved reproductive performance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.