scholarly journals Adsorbents Reduce Aflatoxin M1 Residue in Milk of Healthy Dairy Cow Exposed to Moderate Level Aflatoxin B1 in Diet and Its Exposure Risk for Humans

Toxins ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 665
Author(s):  
Manqian Cha ◽  
Erdan Wang ◽  
Yangyi Hao ◽  
Shoukun Ji ◽  
Shuai Huang ◽  
...  
Keyword(s):  
Milk Yield ◽  
Control Diet ◽  
Daily Intake ◽  
Aflatoxin M1 ◽  
Risk Level ◽  
Exposure Risk ◽  
Moderate Risk ◽  
Effective Measure ◽  
Serum Parameters ◽  
Lactating Cows

This study investigated the effect of moderate risk level (8 µg/kg) AFB1 in diet supplemented with or without adsorbents on lactation performance, serum parameters, milk AFM1 content of healthy lactating cows and the AFM1 residue exposure risk in different human age groups. Forty late healthy lactating Holstein cows (270 ± 22 d in milk; daily milk yield 21 ± 3.1 kg/d) were randomly assigned to four treatments: control diet without AFB1 and adsorbents (CON), CON with 8 μg/kg AFB1 (dry matter basis, AF), AF + 15 g/d adsorbent 1 (AD1), AF + 15 g/d adsorbent 2 (AD2). The experiment lasted for 19 days, including an AFB1-challenge phase (day 1 to 14) and an AFB1-withdraw phase (day 15 to 19). Results showed that both AFB1 and adsorbents treatments had no significant effects on the DMI, milk yield, 3.5% FCM yield, milk components and serum parameters. Compared with the AF, AD1 and AD2 had significantly lower milk AFM1 concentrations (93 ng/L vs. 46 ng/L vs. 51 ng/L) and transfer rates of dietary AFB1 into milk AFM1 (1.16% vs. 0.57% vs. 0.63%) (p < 0.05). Children aged 2–4 years old had the highest exposure risk to AFM1 in milk in AF, with an EDI of 1.02 ng/kg bw/day and a HI of 5.11 (HI > 1 indicates a potential risk for liver cancer). Both AD1 and AD2 had obviously reductions in EDI and HI for all population groups, whereas, the EDI (≥0.25 ng/kg bw/day) and HI (≥1.23) of children aged 2–11 years old were still higher than the suggested tolerable daily intake (TDI) of 0.20 ng/kg bw/day and 1.00 (HI). In conclusion, moderate risk level AFB1 in the diet of healthy lactating cows could cause a public health hazard and adding adsorbents in the dairy diet is an effective measure to remit AFM1 residue in milk and its exposure risk for humans.

scholarly journals Health Risk Assessment for Carcinogenic and Non Carcinogenic Heavy Metal Exposure from Hibiscus Leaf Cultivated in Katsina State, North West Nigeria

2019 ◽  
pp. 1-12
Author(s):  
A. I. Yaradua ◽  
A. J. Alhassan ◽  
A. Nasir ◽  
K. I. Matazu ◽  
A. Usman ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Cancer Risk ◽  
Health Risk ◽  
Hazard Quotient ◽  
Daily Intake ◽  
Health Concern ◽  
Risk Level ◽  
Target Hazard Quotient ◽  
Moderate Risk ◽  
Mean Concentration

This study was conducted to determine the heavy metals concentration in Hibiscus leaves cultivated in Katsina State Nigeria. The objectives were mainly to detect the presence of heavy metals in the cultivated Hibiscus leaves in the study area, compare the concentration of heavy metals in samples in relation to the permissible limits specified by WHO/FAO/USEPA Standards. Samples of cultivated Hibiscus leaves were collected in the year 2017 from the selected area.  Analysis for the concentration of these heavy metals; Cr, Cd, Fe, Ni, Mn, Pb and Zn was conducted by the use of AAS (by Atomic Absorption Spectrophotometry) method. The health risks to the local inhabitants from the consumption of the samples were evaluated based on the Target Hazard Quotient (THQ). The possibility of cancer risks for the adult and children population through intake of carcinogenic heavy metals in the samples was estimated using the Incremental Lifetime Cancer Risk (ILCR). Results from this study shows that with the exception of Pb with mean concentration of (0.508-0.978), the mean concentration (mg/kg) range values of Cr (0.135-0.261), Cd (0.042-0.051), Fe (0.684-0.978) and Zn (1.048-1.208) in the samples were generally lower than the USEPA, WHO/FAO maximum permissive limits. The results have indicated that the estimated daily intake (EDI) of the heavy metals were lower than the tolerable daily intake limit set by the USEPA in both samples and the health risk index (HRI) for all the heavy metals were <1. The target hazard quotient (THQ) for the samples for both the adult and children population was in the decreasing order of Zn>Pb>Fe>Cr>Cd. ILCR for Cd is below the threshold risk limit (>10−5) and ILCR for Pb reached the moderate risk limit (>10−3) in all the studied samples in adults, While in children ILCR for both Pb and Cd in samples from Dabai, Daura, Funtua, Matazu and Zango for all samples have reached the moderate risk limit (>10−3), while the ILCR for Pb in samples from Birchi, Dutsinma, Kafur, Katsina and Malunfashi were beyond the moderate risk level (>10−2). The sampling area trend of risk for developing cancer as a result of consuming the studied samples showed: Funtua > Daura > Dutsinma > Katsina > Malunfashi > Matazu > Zango > Ingawa > Kafur > Dabai > Birchi for both adult and children, cumulative cancer risk (∑ILCR) of all the studied Hibiscus samples have reached the moderate risk limit (>10−3) in adult. While in children with the exception of the sample from Birchi, Dabai and Kafur which are within the moderate cancer risk (>10−3) limit, all other samples were beyond the moderate cancer risk (>10−2) limit. The study suggests that consumption of the studied samples in Katsina state is of public health concern as they may contribute to the population cancer burden. 

scholarly journals Heavy Metal Burden and Evaluation of Human Health Risks in Tomato Fruits Cultivated in Katsina State, North West Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. I. Yaradua ◽  
A. J. Alhassan ◽  
A. Nasir ◽  
M. Bala ◽  
A. Usman ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Health Risks ◽  
Hazard Quotient ◽  
Daily Intake ◽  
Risk Level ◽  
Target Hazard Quotient ◽  
Moderate Risk ◽  
Tomato Fruits ◽  
The Mean

This study was conducted to determine the heavy metals concentration in Tomato fruits cultivated in Katsina State Nigeria. The objectives were mainly to detect the presence of heavy metals in the cultivated Tomato fruits in the study area, compare the concentration of heavy metals in samples in relation to the permissible limits specified by WHO/FAO/USEPA Standards. Samples of cultivated tomato fruits were collected in the year 2017 from the selected areas. Analysis for the concentration of these heavy metals; Cr, Cd, Fe, Ni, Mn, Pb and Zn was conducted by the use of AAS (by Atomic Absorption Spectrophotometry) method. The health risks to the local inhabitants from the consumption of the samples were evaluated based on the Target Hazard Quotient (THQ). The possibility of cancer risks in the samples through intake of carcinogenic heavy metals was estimated using the Incremental Lifetime Cancer Risk (ILCR). Results from this study has shown that with the exception of the mean values for the heavy metal Pb (1.171–1.21 mg/kg), the mean concentration (mg/kg) range values of Zn (0.558- 1.851), Fe (0.880–1.181), Mn (0.458-0.671) and Cd (0.054-0.062) were below the WHO/FAO maximum permissive limits. The results have indicated that the estimated daily intake (EDI) of the heavy metals were lower than the tolerable daily intake limit set by the USEPA in all the samples. All the studied tomato fruits showed the risk level (HI < 1). Risk level of Target Hazard Quotient (THQ < 1) was observed for all the evaluated heavy metals for both adults and children. The THQ for the samples were in the decreasing order Mn>Zn>Pb>Fe>Cd, for all the tomato fruits respectively. ILCR for Cd violated the threshold risk limit (>10−4) and ILCR for Pb reached the moderate risk limit (>10−3) in all the studied samples in adults, While in children ILCR for both Pb and Cd violated the risk. The sampling area trend of risk for developing cancer as a result of consuming the studied samples showed in decreasing order: Daura senatorial zone > Funtua senatorial zone> Katsina senatorial zone for both adult and children.  Cumulative cancer risk (∑ILCR) of all the studied tomato fruits reached the moderate risk limit (>10−3) in adults, while in children it is above the moderate risk limit (>10−2). The study suggests that consumption of the studied tomato fruits in Katsina state is of public health concern as they may contribute to the population cancer burden.

scholarly journals Evaluation of Health Effect of Some Selected Heavy Metals in Maize Cultivated in Katsina State, North West Nigeria

2019 ◽  
pp. 1-12 ◽  
Author(s):  
A. I. Yaradua ◽  
A. J. Alhassan ◽  
L. A. Saulawa ◽  
A. Nasir ◽  
K. I. Matazu ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Cancer Risk ◽  
Health Risks ◽  
Hazard Quotient ◽  
Daily Intake ◽  
Health Concern ◽  
Risk Level ◽  
Target Hazard Quotient ◽  
Cancer Risks ◽  
Moderate Risk

This study was conducted to determine the heavy metals concentration in maize cultivated in Katsina state Nigeria. The objectives were mainly to detect the presence of heavy metals in the cultivated maize in the study area, compare the concentration of heavy metals in samples in relation to the permissible limits specified by WHO/FAO/USEPA Standards and asses the health risks to the local consumers. Samples of cultivated maize were collected in the year 2017 from the selected areas.  Analysis for the concentration of these heavy metals; Cr, Cd, Fe, Ni, Mn, Pb and Zn was conducted by the use of AAS (by Atomic Absorption Spectrophotometry) method. The health risks to the local inhabitants from the consumption of the samples were evaluated based on the Target Hazard Quotient (THQ). The possibility of cancer risks in the samples through the intake of carcinogenic heavy metals was estimated using the Incremental Lifetime Cancer Risk (ILCR).  Results from this study have shown that with the exception of the heavy metal Pb the concentration values of Cr, Cd, Fe, Mn and Zn in the samples were generally lower than the USEPA, WHO/FAO maximum permissive limits. The results have also indicated that the estimated daily intake of the heavy metals was lower than the tolerable daily intake limit set by the USEPA in all samples. The risk level of Target Hazard Quotient (THQ < 1) was observed for all the evaluated heavy metals for both adults and children.. The THQ for the samples was in the decreasing order Zn>Pb>Fe>Cr>Cd, for all the samples respectively. All the studied samples showed the hazard index (HI < 1) with highest in the sample from Dabai and lowest in the sample from Funtua. In adults the ILCR for Cd violated the threshold risk limit (>10−4) in all the studied samples, while the ILCR for Pb reached the moderate risk limit (>10−3) except for the sample from Kafur which is above the limit (>10−2). In children ILCR for Cd in all samples and Pb for samples from Birchi, Katsina and Malunfashi has reached the moderate risk limit (>10−3) while the ILCR for Pb in samples from Dabai, Funtua and Kafur is above the limit (>10−2). The trend of risk for developing cancer as a result of consuming the studied maize samples showed: Kafur> Dabai > Funtua> Malunfashi > Katsina. Cumulative cancer risk (∑ILCR) in adults of all the studied maize samples reached the moderate risk limit (>10−3) except for sample from Kafur which is above the moderate risk limit (>10−2). While the cumulative cancer risk (∑ILCR) in children of all the studied maize samples is above the moderate risk limit (>10−2) except for sample from Katsina which is within the moderate risk limit (>10−3). Among all the studied samples maize sample from Kafur has the highest chances of cancer risks (ILCR 1.297980 × 10−2 in adults, 1.510018 × 10−2 in children) and sample from Katsina has the lowest chances of cancer risk (ILCR 1.68603093 × 10−3 in adults, 7.775840 × 10−3 in children). The study suggests that consumption of the studied maize samples in Katsina state is of public health concern as they may contribute to the population cancer burden. 

Dietary Exposure of Heavy Metals, Minerals and Trace Elements through Cereals Commonly Consumed by Dhaka City Residents

2020 ◽  
Vol 16 (5) ◽  
pp. 815-823
Author(s):  
Md. Bayejid Hosen ◽  
Abu T.M. Abdullah ◽  
Md. Z.H. Howlader ◽  
Yearul Kabir
Keyword(s):  
Heavy Metals ◽  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Industrial Development ◽  
Daily Intake ◽  
Dietary Exposure ◽  
Risk Level ◽  
Dhaka City ◽  
Main Meal ◽  
Minerals And Trace Elements

Background: Contamination of soil and agricultural products by heavy metals resulting from rapid industrial development has caused major concern. Dietary exposure to heavy metals has been associated with toxic and adverse health effects. The main threats to human health from heavy metals are associated with exposure to Pb, Cd and Hg. The aim of this study was to monitor the presence of heavy metals, minerals and trace elements in cereals consumed by Dhaka city residents. Methods: One hundred and sixty cereal samples were collected for eight (08) composited samples and analyzed for the determination of sixteen elements. Heavy metals were analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), and other elements were determined by Atomic Absorption Spectrometry (AAS). Results: The average concentrations of elements in cereals fall within the safe limit except for Pb, Cr, Na and Mg, which exceeded the safe limits. The daily intake of Cd (23.0 μg), Hg (63.0 μg) and As (13.6 μg) through cereals was below the risk level except for Pb (634.0 μg) and Cr (263.1 μg). The dietary intake of Na (1860.0 mg), Mg (347.0 mg) and Mn (4600.0 μg) exceeded the toxic level while K (829 mg) was below the RDA. Conclusion: As the main meal of average Bangladeshi people is boiled rice served with some vegetables, our findings indicate that the residents of Dhaka city are at risk from Pb and Cr contamination and their dietary need for some important minerals and trace elements is not fulfilled by cereals.

Effect of Bypass Protein on Milk Production and Economic of Lactating Crossbred Cows

2020 ◽  
Vol 7 (01) ◽  
Author(s):  
RATNESH K CHOUDHARY ◽  
A Saran ROY ◽  
N K SINGH3 ◽  
SANJAY KUMAR ◽  
RAUSHAN K SINGH
Keyword(s):  
Milk Production ◽  
Milk Yield ◽  
Crossbred Cows ◽  
Lactating Cows ◽  
Feed Cost ◽  
Total Diet ◽  
T1 And T2 ◽  
Daily Milk Yield ◽  
On Farm ◽  
Daily Milk

An On-Farm Trial was conducted on 24 lactating crossbred cows for assessment of feeding formaldehyde treated mustard cake (bypass protein) on milk production and economic analysis of lactating cow. Cows were divided into three groups having 8 cows each, treatments were farmers’ practice (FP); (Control): The lactating animals under this group were fedas per the feeding schedule of the farmers (5 kg. dry roughage as rice straw + 6 hrs grazing as local grass and 4 kg. commercial concentrates), T1: The lactating animals under this group were fed as per farmers practicewith 12% mustard cake of total diet was provided to the cow by replacing the same amount of commercial concentrates andT2: The lactating animals under this group were fed as per farmers practicewith 12% formaldehyde treated mustard cake of total diet was provided to the cow by replacing same amount of commercial concentrates. The average daily milk yield of lactating cows under FP, T1 and T2 was 8.58, 8.82 and 9.85 kg per cow, respectively. Differences between FP and T2 were significant. The daily increase in milk yield was 1.27 kg and 1.03 kg in cows fed T2diet over the cows fed FP and T1diet, respectively. The B: C ratios for FP, T1 and T2 groups were 2.6, 3.0 and 3.3, respectively. The feed cost reduced in T2 group by Rs. 8.64 and increased milk production by 1.27 kg in respect to FP group.

scholarly journals Characterization of Short-Term Heat Stress in Holstein Dairy Cows Using Altered Indicators of Metabolomics, Blood Parameters, Milk MicroRNA-216 and Characteristics

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 722
Author(s):  
Jang-Hoon Jo ◽  
Jalil Ghassemi Nejad ◽  
Dong-Qiao Peng ◽  
Hye-Ran Kim ◽  
Sang-Ho Kim ◽  
...  
Keyword(s):  
Heat Stress ◽  
Dairy Cows ◽  
Milk Yield ◽  
Milk Fat ◽  
Blood Parameters ◽  
Negative Effects ◽  
Short Term ◽  
Lactating Cows ◽  
Humidity Index ◽  
Holstein Dairy Cows

This study aims to characterize the influence of short-term heat stress (HS; 4 day) in early lactating Holstein dairy cows, in terms of triggering blood metabolomics and parameters, milk yield and composition, and milk microRNA expression. Eight cows (milk yield = 30 ± 1.5 kg/day, parity = 1.09 ± 0.05) were homogeneously housed in environmentally controlled chambers, assigned into two groups with respect to the temperature humidity index (THI) at two distinct levels: approximately ~71 (low-temperature, low-humidity; LTLH) and ~86 (high-temperature, high-humidity; HTHH). Average feed intake (FI) dropped about 10 kg in the HTHH group, compared with the LTLH group (p = 0.001), whereas water intake was only numerically higher (p = 0.183) in the HTHH group than in the LTLH group. Physiological parameters, including rectal temperature (p = 0.001) and heart rate (p = 0.038), were significantly higher in the HTHH group than in the LTLH group. Plasma cortisol and haptoglobin were higher (p < 0.05) in the HTHH group, compared to the LTLH group. Milk yield, milk fat yield, 3.5% fat-corrected milk (FCM), and energy-corrected milk (ECM) were lower (p < 0.05) in the HTHH group than in the LTLH group. Higher relative expression of milk miRNA-216 was observed in the HTHH group (p < 0.05). Valine, isoleucine, methionine, phenylalanine, tyrosine, tryptophan, lactic acid, 3-phenylpropionic acid, 1,5-anhydro-D-sorbitol, myo-inositol, and urea were decreased (p < 0.05). These results suggest that early lactating cows are more vulnerable to short-term (4 day) high THI levels—that is, HTHH conditions—compared with LTLH, considering the enormous negative effects observed in measured blood metabolomics and parameters, milk yield and compositions, and milk miRNA-216 expression.

A COMPARISON OF TWO METHODS OF COMBINING ALFALFA CUBES WITH CORN SILAGE FED TO LACTATING COWS

1977 ◽  
Vol 57 (3) ◽  
pp. 559-565
Author(s):  
L. J. FISHER
Keyword(s):  
Milk Yield ◽  
Dry Matter ◽  
Protein Digestibility ◽  
Corn Silage ◽  
Feeding Time ◽  
Plasma Urea ◽  
Lactating Cows ◽  
Fat Yield ◽  
Changeover Period ◽  
Feeding Systems

Sixteen Holstein cows in early lactation were assigned to a switch-back experiment consisting of two experimental periods 35 days in length separated by a 7-day changeover period. Treatments consisted of two feeding systems, alfalfa cubes ensiled with corn silage or alfalfa cubes fed with the corn silage. When cows were fed corn–alfalfa cube silage they consumed more forage, 2.26 vs. 2.16% of body weight per cow per day than when they were fed the alfalfa cubes with the silage. Fat-corrected milk yield was somewhat higher, 25.4 vs. 24.0 kg/day; fat percent and fat yield were greater, 3.13 vs. 2.70% and 918 vs. 814 g/day for corn–alfalfa cube silage as compared to cubes added at feeding time. However, milk yield was greater, 29.9 vs. 29.1 kg/day, and milk lactose percent was greater, 5.26 vs. 5.18% for cows fed cubes at feeding time compared to cows fed corn–alfalfa cube silage. There was no difference between feeding systems in blood minerals or metabolites with the exception of plasma urea nitrogen which was higher, 20.2 vs. 17.2 mg %, for the alfalfa cubes fed with the corn silage. Apparent dry matter and protein digestibility for the total ration were 68.1 and 71.6% when corn alfalfa cube silage was fed compared to 65.4 and 68.5% when the cubes were fed with the corn silage (P < 0.05). It was concluded from this study that alfalfa cubes ensiled with corn silage was an effective method of increasing the dry matter and protein content of corn silage and in improving the digestibility of the total ration.

SUBSTITUTION OF RAPESEED MEAL FOR SOYBEAN MEAL AS A SOURCE OF PROTEIN FOR LACTATING COWS

1976 ◽  
Vol 56 (2) ◽  
pp. 233-242 ◽  
Author(s):  
L. J. FISHER ◽  
DOROTHY S. WALSH
Keyword(s):  
Milk Yield ◽  
Dry Matter ◽  
Rapeseed Meal ◽  
Milk Composition ◽  
Hormone Metabolism ◽  
Thyroid Hormone Metabolism ◽  
Lactating Cows ◽  
Lower Blood ◽  
Concentrate Mixture ◽  
Low Erucic Acid

Sixteen lactating Holstein cows were randomly assigned to treatment sequences in a 4 × 4 changeover experiment. Experimental periods were 28 days in length separated by 7 days for changeover. Cows were fed corn silage free choice and gradually increasing amounts of one of four dairy concentrates containing 0, 11, 22, or 34% rapeseed meal (RSM) of a Canadian, experimental, low glucosinolate–low erucic acid variety. Concentrate intake (kg dry matter/day), milk yield (kg/day) and body weight change (kg/28 days) were 8.45a, 8.71a, 8.37a and 7.17b; 24.40a, 24.03ab, 22.92bc and 21.96c and 7.6b, 22.4b, 13.0ab, and 3.0b for 0, 11, 22 and 34% RSM mixtures, respectively. There was no influence of treatment on milk composition. Ration dry matter (DM) and nitrogen digestibilities declined (P < 0.05) as the RSM in the concentrate mixture increased. The amount of nitrogen excreted in the urine was greatest for cows fed 0% RSM and least for cows fed 34% RSM. Cows fed concentrate mixtures containing 34% RSM had a lower blood thyroxine level than others (P < 0.05), but RSM-containing concentrates had no apparent effect on the conversion of thyroxine to triiodothyronine. Results of the trial indicated that this experimental variety of RSM had no detrimental effect on concentrate intake, DM digestibility, milk composition or thyroid hormone metabolism when included at levels up to 22% in the concentrate mixture. However, milk yield and apparent digestibility of ration nitrogen were decreased (P < 0.05) by the 22% RSM mixture. It was not certain from the current findings whether the depression in digestibility was due largely to the high oil content of the meal or due to the higher fiber content of the RSM-supplemented rations.

scholarly journals 127 Predicting Dry Matter Intake of Gestating and Lactating Beef Cows

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 58-58
Author(s):  
Megan A Gross ◽  
Claire Andresen ◽  
Amanda Holder ◽  
Alexi Moehlenpah ◽  
Carla Goad ◽  
...  
Keyword(s):  
Beef Cattle ◽  
Milk Yield ◽  
Feed Intake ◽  
Beef Cows ◽  
Multiple Regression Equation ◽  
Validation Data ◽  
Data Set ◽  
Lactating Cows ◽  
Downward Bias ◽  
Protein Supply

Abstract In 1996, the NASEM beef cattle committee developed and published an equation to estimate cow feed intake using results from studies conducted or published between 1979 and 1993 (Nutrient Requirements of Beef Cattle). The same equation was recommended for use in the most recent version of this publication (2016). The equation is sensitive to cow weight, diet digestibility and milk yield. Our objective was to validate the accuracy of this equation using more recent published and unpublished data. Criteria for inclusion in the validation data set included projects conducted or published within the last ten years, direct measurement of forage intake, adequate protein supply, and pen feeding (no tie stall or metabolism crate data). The validation data set included 29 treatment means for gestating cows and 26 treatment means for lactating cows. Means for the gestating cow data set was 11.4 ± 1.9 kg DMI, 599 ± 77 kg BW, 1.24 ± 0.14 Mcal/kg NEm per kg of feed and lactating cow data set was 14.5 ± 2.0 kg DMI, 532 ± 116.3 kg BW, and 1.26 ± 0.24 Mcal NEm per kg feed, respectively. Non intercept models were used to determine equation accuracy in predicting validation data set DMI. The slope for linear bias in the NASEM gestation equation did not differ from 1 (P = 0.07) with a 3.5% positive bias. However, when the NASEM equation was used to predict DMI in lactating cows, the slope for linear bias significantly differed from 1 (P &lt; 0.001) with a downward bias of 13.7%. Therefore, a new multiple regression equation was developed from the validation data set: DMI= (-4.336 + (0.086427 (BW^.75) + 0.3 (Milk yield)+6.005785(NEm)), (R-squared=0.84). The NASEM equation for gestating beef cows was reasonably accurate while the lactation equation underestimated feed intake.

The control of appetite in lactating cows

1972 ◽  
Vol 14 (3) ◽  
pp. 263-281 ◽  
Author(s):  
L. S. Monteiro
Keyword(s):  
Body Weight ◽  
Food Intake ◽  
Milk Yield ◽  
Closed Loop ◽  
Loop System ◽  
Closed Loop System ◽  
Lactating Cows ◽  
Body Reserves ◽  
Lactation Curve ◽  
Rate Of Increase

SUMMARYA closed-loop system is proposed for the control of voluntary food intake in lactating cows, and an expression is deduced relating the response of food intake to changes in milk yield and body-weight gain.A closed-loop system necessarily involves a delay in the response to changes in production. The rate of increase of food intake is there- fore slower than the rate of increase in milk yield. The consequent deficit in energy during the rising part of the lactation curve is met by the mobilization of body reserves, which are partly accounted for by losses in body weight. During the declining part of the lactation the delay effect leads to an excess of energy intake and to the replacement of body reserves and, consequently, of body weight.The expression deduced from the model was fitted to four different types of lactation curve corresponding to long and short lactations of Friesians and Jerseys fed ad libitum on a complete diet. The expected food intake based on the control model was contrasted with a linear regression model. The former gave a better account of the variation in food intake in all four types of lactation.The total change in body weight during lactation was partitioned between changes in weight due to the mobilization and replacement of reserves and gain directly attributable to food intake. There was, in general, good agreement between the observed losses in weight occurring at the beginning of lactation and those predicted from the mobilization of reserves for milk production.The physiological implications of the model and the values estimated for the parameters are discussed.

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