Milk and fat production of crossbred Holstein-Gir cows (Bos taurus taurus-Bos taurus indicus) in the agreste region of the Brazilian state of Pernambuco

Abstract

The productive performance of four Holstein-Gir genetic groups (1/2H, 1/4H, 5/8H, 5/8Hinter se) and the effects of non-genetic factors on production traits was evaluated using a data set of 7,951 test-day samples collected between January 1980 and December 1999 from the Arcoverde Experimental Station in the Brazilian state of Pernambuco (Empresa Pernambucana de Pesquisa Agropecuária). The statistical model included the fixed effects of calving year (1980 to 1999) and month (January to December), genetic group of the cow, age at months of calving (33 to 190) and days in milk at each test-day. Random effects were sire, cow and residual with test-days treated as repeated records within each cow within each lactation. For the four genetic groups the milk yield (MY) means were 1/2H = 8.61 kg ± 1.16 kg, 1/4H = 5.34 kg ± 0.46 kg, 5/8H = 7.42 kg ± 0.39 kg and 5/8Hinter se = 5.76 kg ± 0.46 kg; the fat yield (FY) means were 1/2H = 0.375 kg ± 0.052 kg, 1/4H = 0.231 kg ± 0.026 kg, 5/8H = 0.299 kg ± 0.025 kg and 5/8Hinter se = 0.231 kg ± 0.026 kg; and the fat percentage (FP) means were 1/2H = 4.45 kg ± 0.29%, 1/4H = 4.08 kg ± 0.12%, 5/8H = 3.87 kg ± 0.10% and 5/8Hinter se = 3.89 kg ± 0.12%. Phenotypic correlations between tests were MY = 0.97, FY = 0.94 and FP = 0.98. The best productive performance was for the 1/2H group, followed by the 5/8H group. The performance of the synthetic group was substantially below the performance of the 5/8H group.

Milk Production and Constituents of Beef Cows with Different Breed Compositions

“…In this sense, Ribeiro et al [6], evaluating 182 days of lactation, found a daily linear increase of 0.0124% in the milk fat content of Charolais cows. Also agreeing with this study, other authors reported a decrease in lactose content until the end of lactation due to a positive correlation with milk production and osmotic balance [54][55][56] and Restle et al [18] found a maximum concentration (5.13%) at the peak of lactation.…”

Genetic Parameters of Girolando Crossbred Cows in Dairy Herds in the State of Acre, Brazil

“…The means estimated for milk production up to 305 days ranged between the minimum of 561.32 ± 685.91SD kg and the maximum of 2,875.32 ± 950.46SD kg, revealing the existence of management differences and genetic potential within the group of herds analyzed. The results of the analysis of variance of milk production (Table 1) indicate that the effects of herd, month of birth, and control period were significant (P<0.01), which was also detected by other authors (BARBOSA et al, 2008;HERRERA et al, 2008) who studied Zebu cattle, demonstrating that the fixed effects directly interfered on milk production. It was verified through the descriptive analysis that the cows presented lower production in the rainy-dry transition periods and in the dry season, respectively, which is probably due to the quantity and quality of the pastures and supplementation available at this time which contributes to the decrease in milk production.…”

Electrical conductivity and somatic cell count in zebu cow’s milk

“…An increase in the milk's fat content is related to the decrease in the milk's ability to conduct electrical current as fat is a poor conductor and the increase in the lipid fraction of milk results in an inhibiting ECM effect; not only by reducing the total conductive medium but, also by the physical obstacle that the fat globules offer to the migration of ions. It is also important to note that within the breed parameter, the zebu cows have a higher fat content in milk compared to Holstein cows and their crosses (MABROOK;PETTY 2003;ZAFALON et al, 2005;BARBOSA et al, 2008;KAŞIKÇI et al, 2012).…”