Browsing by Author "Seegmuller, Andre Joseph"

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    Periparturient rumen undegradable protein and colostrum quality in Dohne Merino and Meatmaster ewes
    (Stellenbosch : Stellenbosch University, 2024-03) Seegmuller, Andre Joseph; Van Zyl, Johan Hendrik Combrink; Lambrechts, Helet; Stellenbosch University. Faculty of AgriSciences. Dept. of Animal Science.
    ENGLISH ABSTRACT: Sheep and goat farming are considered vital to sustain the economy in extensive farming regions, due to the ability of these species to thrive in very warm and arid environments. Although mutton and lamb production only contributed 3.76% to the total gross value generated from animal products during the last decade, sheep is still the second most abundant livestock species, after poultry, in South Africa. Due to recent declines in sheep numbers, strategies to optimise production are needed. The improvement in the number of lambs sold per ewe, attainment of weaning weight sooner, and optimized lamb growth rate, can all contribute to increase the revenue generated from fewer animals. Two suggested strategies to achieve higher lamb survivability and lamb growth include the optimization of the milk production and composition produced by ewes, and in particular improving colostrum production and quality through the provision of supplementary feeding, thereby improving passive immunity leading the lower lamb mortality. To ensure sustainable lamb and mutton production and to ensure viability of sheep production in South Africa, it is imperative that local sheep producers continuously adapt and improve their production practices to be able to contribute to job and food security while ensuring sustained profitability. The objectives of the study were to evaluate the effect of increased pre-partum rumen undegradable protein (RUP) intake on colostrum quality, colostrum viscosity, lamb survival rate, lamb growth rate as well as the effect of all of the above on extensive (Meatmaster) and intensive (Dohne Merino) sheep breeds. The first part of the study determined the effect of the level of pre-partum RUP supplementation of ewes on colostrum and milk production, as well as lamb rearing ability. Inclusion levels of 220 g/kg and 400 g/kg RUP of total crude protein (CP) were evaluated. The breed effect was also investigated in this study to evaluate the effect of partitioning of nutrients towards production. During the 11-week trail post-partum production performance of 18 Meatmaster (MM) and 18 Dohne Merino (DM) ewes were compared. Daily dry matter intake (DMI) and weekly body weights were used to calculate weekly average daily gain (ADG) and feed conversion ratio (FCR). Blood samples were collected 1 week pre-partum, at parturition and 1-week post-partum to determine the total protein, albumin and alkaline phosphatase (ALP) enzymatic levels in the plasma in the ewes. Colostrum samples were collected 1-, 10- and 18 hours post-partum to determine the colostrum quality over time. Milk samples were collected at 2-, 4-, and 6 weeks post-partum to investigate the composition of the milk at three different stages of lactation. Diet RUP level did not affect DMI, ADG or FCR of the ewes in this study. Ewe breed influenced somatic cell count (SCC), butterfat concentration and total solids, percentage lactose, and milk urea nitrogen for all colostrum samples. The 22% RUP diet fed resulted in the 18 h colostrum samples that were characterized by higher viscosity, immunoglobulin G- (IgG ) and total protein levels. Milk produced by the MM ewes was characterized by higher butterfat concentration and total solids recorded for all three stages of lactation. The milk produced by the DM was characterized by higher SSC recorded during mid-lactation. No differences in udder or teat dimensions were observed. In conclusion, ewe breed had a limited effect on milk production parameters recorded in this study, while diet RUP level resulted in a moderate response with regard to colostrum- and milk production. The second part of the study investigated the effect of ewe breed and pre-partum diet RUP level on ewe colostrum production and the effect thereof on pre-weaning lamb growth and passive immunity. Four treatment combinations were used in this trail; lambs born from Meatmaster ewes that received the 22% RUP pre-partum diet (22%MM), lambs born from Dohne Merino ewes that received the 22% RUP pre-partum diet (22%DM), lambs born from Meatmaster ewes that received the 40% RUP pre-partum diet (40%MM), lambs born from Dohne Merino ewes that received the 40% RUP pre-partum RUP diet (40%DM). During the 7-week post-partum period lambs were weighed weekly to determine weekly weight gain and average daily gain (ADG). Blood samples were collected to determine success of serum immunoglobulin G (Brix’s %) transfer to lambs. Results indicate that pre-weaning lamb growth was not influenced by ewe colostrum- and milk production and quality respectively. Significant interaction between the 4 treatment combinations were however found for birth weight, and ADG and weaning weight of lambs. No difference between treatment combinations was found in birth weight and weaning weight, although the ADG of the 22%MM were lower compared to the 40%DM treatment. Ewe pre-partum diet did not affect lamb serum IgG level and weaning age. The ewe breed did not have any effect on age at weaning and lamb serum IgG level. It was concluded that ewe colostrum- and milk quality produced by the ewes receiving the respective treatments had little response on lamb production. Results from the current study therefore indicate that 22% RUP during the pre-partum period of ewes is sufficient to both Dohne Merino and Meatmaster ewes lambing in intensive pens as little response on both vectors were found in ewe and lamb results. It is therefore concluded that, under the specific conditions of the trial, that the additional cost that would be incurred by increasing the RUP level above 22% of crude protein, could not be justified.