ABSTRACT
When the daily routine of a cow is disturbed, it may have a detrimental effect on the performance of activity meters to detect estrus. It is possible that during the pasture period, the daily routine of cows is disturbed, adversely affecting the performance of activity meters to detect estrus which does not happen when the cows are housed indoors. The objective of this study was to investigate whether housing conditions (pasture or indoor) affected the performance of activity meters to detect estrus in dairy cows. In this research, two types of activity meters were used, an activity meter attached to the leg and one mounted on the neck. Cows of two different herds were equipped with the Smarttag Leg and the Smarttag Neck (Nedap livestock management, Groenlo, the Netherlands). The study began during the pasture period (September) and ended during the indoor period (January). The pasture period ended at the beginning of November. So, about two months of pasture period and two months of indoor period were studied. Milk samples were collected twice a week during the morning milking and true estrus was determined by milk progesterone concentrations. In total, the dataset consisted of 95 true estrous periods and 1992 true non-estrous days of 56 cows for the pasture period and 138 true estrous periods and 3164 true non-estrous days of 65 cows for the indoor period. Overall, no differences in sensitivity, positive predictive value (PPV) and specificity were found between the pasture and indoor period for both types of sensors. There was also no difference in the performance between leg and neck activity meters. Sensitivity was between 76 and 82%, PPV was between 87 and 92% and specificity was between 99 and 100%. In conclusion, the sensitivity, PPV and specificity did not differ between the pasture and indoor period. This means that, in our study, the performance of both types of activity meters to detect estrus is not affected by housing conditions.
Subject(s)
Cattle/physiology , Estrus Detection/instrumentation , Housing, Animal , Animals , Behavior, Animal , Dairying , Estrus/physiology , Extremities , Female , Milk/chemistry , Neck , Netherlands , Progesterone/analysis , Seasons , Sensitivity and SpecificitySubject(s)
Diet , Dietary Proteins/pharmacology , Pesticides/toxicity , Animals , Body Temperature , Body Weight , Carbaryl/toxicity , Caseins , Chlorpropham/toxicity , DDT/toxicity , Endosulfan/toxicity , Herbicides/toxicity , Hexachlorocyclohexane/toxicity , Indoles/toxicity , Insecticides/toxicity , Lethal Dose 50 , Malathion/toxicity , Male , Pyrimidines/toxicity , RatsSubject(s)
Cottonseed Oil/toxicity , Protein Deficiency/complications , Alopecia/chemically induced , Animals , Behavior, Animal/drug effects , Brain/drug effects , Caseins , Cerebral Hemorrhage/chemically induced , Cottonseed Oil/metabolism , Diarrhea/chemically induced , Dietary Proteins , Humans , Intestinal Absorption , Intestines/drug effects , Kidney/drug effects , Kidney Tubules/pathology , Lethal Dose 50 , Liver/metabolism , Male , Rats , Self MutilationSubject(s)
Benzothiepins/toxicity , Bridged-Ring Compounds/toxicity , Dietary Proteins , Terpenes/toxicity , Administration, Oral , Animals , Benzothiepins/administration & dosage , Benzothiepins/poisoning , Brain/drug effects , Brain/pathology , Bridged-Ring Compounds/administration & dosage , Bridged-Ring Compounds/poisoning , Caseins , Liver/drug effects , Liver/pathology , Male , Protein Deficiency/complications , Rats , Terpenes/administration & dosage , Terpenes/poisoningSubject(s)
Dietary Proteins , Insecticides/toxicity , Phosphoric Acids/toxicity , Thiomalates/toxicity , Administration, Oral , Anilides/toxicity , Animals , Benzothiepins/toxicity , Bridged-Ring Compounds/toxicity , Carbamates/toxicity , Caseins , Hexachlorocyclohexane/toxicity , Indoles/toxicity , Male , Naphthalenes/toxicity , Pyrimidines/toxicity , Rats , Terpenes/toxicity , Urea/toxicitySubject(s)
Body Weight , Organ Size , Phenacetin/toxicity , Animals , Female , Heart , Kidney , Liver/pathology , Lung , Male , Muscles , Ovary , Phenacetin/administration & dosage , Phenacetin/poisoning , Rats , Sex Factors , Skin , Spleen , Stomach/pathology , TestisABSTRACT
Albino rats fed for 28 days from weaning on diets containing progressively smaller percentages of casein become progressively more susceptible to the lethal effects of single toxic oral doses of DDT than are rats fed normal amounts of dietary casein (27%). When the amount of casein in the diet is increased to 81%, the LD50 also declines. The clinical signs of toxicity to DDT at the range of the acute oral LD50 were similar in animals of all dietary groups studied.
