scholarly journals Genetic Parameters and Trends of Milk, Fat, Days Open, and Body Weight After Calving in North Carolina Experimental Herds

2000 ◽  
Vol 83 (6) ◽  
pp. 1364-1370 ◽  
Author(s):  
J.M. Abdallah ◽  
B.T. McDaniel
2021 ◽  
pp. 1-8
Author(s):  
Maroula Lambidou ◽  
Birgit Alteheld ◽  
Rolf Fimmers ◽  
Frank Jochum ◽  
Antonia Nomayo ◽  
...  

<b><i>Introduction:</i></b> Recently, new commercial infant formulas have been composed considering novel fat blends and oligosaccharides to better resemble the fatty acid (FA) composition and stereospecific distribution (e.g., increased amount of ß-palmitate) as well as probiotics content of human breast milk. We hypothesized that these newly composed infant formulas may decrease fecal FA soap excretion and may positively affect erythrocyte FA profiles compared with regular formulas. <b><i>Methods:</i></b> Healthy infants were randomly assigned to receive a high-sn-2-palmitate formula (&#x3e;25% of the PA is esterified to the sn-2 position of the glycerol backbone, verum: <i>n</i> = 30) or a “standard” formula containing &#x3c;10% of PA in sn-2 position and no oligosaccharides (control: <i>n</i> = 27); a non-randomized group of breast-fed infants served as control. Anthropometric data of the infants (body weight, recumbent length, and head circumference) were recorded at inclusion (visit 1) and 6 and 12 weeks after onset of intervention (visits 2 and 3). Blood samples for erythrocyte FA analysis (gas chromatography) were taken at visits 1 and 2; stool samples were collected at visit 2. <b><i>Results:</i></b> Quantitative formula intake (mL/kg body weight × day) at visit 2 (verum: 155 ± 30, control: 164 ± 30) and visit 3 (verum: 134 ± 26, control: 134 ± 21) was comparable. Six weeks after onset of intervention, stool total FA soaps, palmitate soaps, and total FAs were similar in both formula-fed groups but significantly higher than in breast-fed infants. During the 6-week intervention, erythrocyte palmitate decreased significantly from baseline in all 3 groups with no group differences (verum: 29.20 ± 1.17 to 27.12 ± 0.66, control: 29.88 ± 2.00 to 27.01 ± 0.94, breast-fed: 30.20 ± 0.86 to 26.84 ± 0.98). For selected FAs, significant changes over time in verum and control group were obvious but without formula effects. Some variations in the FA profile of breast-fed infants compared to both verum and control groups were observed. <b><i>Conclusions:</i></b> In contrast to our hypothesis, feeding a newly composed infant formula based on a fat blend with 25% of PA in the sn-2 position of triacylglycerols and supplemented with a prebiotic could not decrease insoluble FA soap excretion compared with a standard product; in this respect, breastfeeding is obviously the best choice. Surprisingly, erythrocyte FA profiles were comparable in formula-fed and breast-fed infants; obvious alterations in FA composition of the respective fat sources and structure did not affect FA incorporation into membranes. Caution should be, however, exercised in drawing robust conclusions in the absence of larger, adequately powered intervention studies.


Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 220
Author(s):  
Manuel J. Flores-Najera ◽  
Venancio Cuevas-Reyes ◽  
Juan M. Vázquez-García ◽  
Sergio Beltrán-López ◽  
César A. Meza-Herrera ◽  
...  

We tested whether the milk yield capacity of mixed-breed goats on a Chihuahuan desert rangeland in northern Mexico during the dry season affects milk composition, body weight gain, and weaning weight of their progeny. Milk yield and composition, and progeny postnatal growth performance, were recorded weekly. One week after kidding, mixed-breed goats (a mixture of Criollo × dairy breeds; n = 40) were allotted into medium (MP) or low (LP) milk yielding groups (20 goats per group). Mean 105-d total milk yield for MP and LP goats was 45.2 ± 12.5 and 20.7 ± 5.2 L, respectively. Milk lactose (4.3 vs. 4.2%) and solids-non-fat (SNF; 8.2 vs. 8.0) differed (p < 0.05) between MP and LP goats; milk protein content tended to differ (p = 0.08) between MP and LP goats with no difference for milk fat content (p > 0.05). Maternal body weight was positively associated with milk yield, milk lactose, and SNF content (p < 0.05 to p < 0.001). Goats giving birth to males produce more milk than goats giving birth to females, but milk fat percentage was higher in goats bearing females (p < 0.001). Milk yield and composition throughout lactation did not influence body weight gain (47.8 vs. 48.7 g/day for kids from MP and LP goats) and weaning weight (6.7 vs. 6.7 kg from MP and LP goats) of the offspring (p > 0.05). Birth weight and weaning weight of the progeny were positively related to maternal body weight (p ≤ 0.05). The postnatal growth of the kids was reduced, extending the time to reach market weight. Nevertheless, non-supplemented mixed-breed goats reared on semi-arid rangeland of northern Mexico have the potential for moderate milk production. Therefore, due to the limited nutrients ingested by grazing goats during the dry season, a nutritional supplement is necessary to keep up milk production and adequate growth of kids.


2018 ◽  
Vol 41 (1) ◽  
pp. 42552
Author(s):  
Fatima Kouri ◽  
Salima Charallah ◽  
Amina Kouri ◽  
Zaina Amirat ◽  
Farida Khammar

 This research aims to assess the performances of lactating Bedouin goat under arid conditions, focusing on the relationship of milk yield with body and udder morphology and growth traits. Fourteen goats and their kids were followed during early lactation (90 days post-partum). Mean daily milk yield was 0.56 kg. Milk fat, proteins, lactose, solids non-fat and minerals were respectively 34.9, 38.9, 48.8, 107 and 6.7 g L-1. Mean kids’ birth weight, adjusted body weight at 90 days of age and average daily gain were respectively 2 kg, 6.6 kg and 51.4 g day-1. Daily milk yield was correlated with goats’ body weight, withers height, rump height, udder width and udder circumference but not with linear udder score and growth performances. These results provide important data about the milk production of Bedouin goat emphasizing its correlation with body and udder morphological traits which can help to elaborate a specific breeding program for this breed. 


2016 ◽  
Vol 15 (2) ◽  
Author(s):  
S.L.C. Meirelles ◽  
F.B. Mokry ◽  
A.C. Espasandín ◽  
M.A.D. Dias ◽  
M.M. Baena ◽  
...  

1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.


2011 ◽  
Vol 34 (3) ◽  
pp. 429-434 ◽  
Author(s):  
Beatriz do Nascimento Nunes ◽  
Salvador Boccaletti Ramos ◽  
Rodrigo Pelicioni Savegnago ◽  
Mônica Corrêa Ledur ◽  
Kátia Nones ◽  
...  

2016 ◽  
Vol 59 (2) ◽  
pp. 243-248 ◽  
Author(s):  
Hafedh Ben Zaabza ◽  
Abderrahmen Ben Gara ◽  
Hedi Hammami ◽  
Mohamed Amine Ferchichi ◽  
Boulbaba Rekik

Abstract. A multi-trait repeatability animal model under restricted maximum likelihood (REML) and Bayesian methods was used to estimate genetic parameters of milk, fat, and protein yields in Tunisian Holstein cows. The estimates of heritability for milk, fat, and protein yields from the REML procedure were 0.21 ± 0.05, 0.159 ± 0.04, and 0.158 ± 0.04, respectively. The corresponding results from the Bayesian procedure were 0.273 ± 0.02, 0.198 ± 0.01, and 0.187 ± 0.01. Heritability estimates tended to be larger via the Bayesian than those obtained by the REML method. Genetic and permanent environmental variances estimated by REML were smaller than those obtained by the Bayesian analysis. Inversely, REML estimates of the residual variances were larger than Bayesian estimates. Genetic and permanent correlation estimates were on the other hand comparable by both REML and Bayesian methods with permanent environmental being larger than genetic correlations. Results from this study confirm previous reports on genetic parameters for milk traits in Tunisian Holsteins and suggest that a multi-trait approach can be an alternative for implementing a routine genetic evaluation of the Tunisian dairy cattle population.


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