Periparturient rumen undegradable protein and colostrum quality in Dohne Merino and Meatmaster ewes

Date
2024-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
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.
AFRIKAANSE OPSOMMING: Skaap- en bokboerdery is van uiterste belang vir volhoubare ekonomiese oorlewing in die ekstensiewe areas van Suid-Afrika vanweë die vermoë van hierdie diere om in uiterste omstandighede goed te kan presteer. Ten spyte daarvan dat skaapproduksie slegs 3.76% tot die totale bruto waarde van diereproduksie bygedra het in die laaste dekade, is skaapgetalle naas pluimvee, steeds die tweede hoogste in Suid-Afrika. ‘n Onlangse afname in skaapgetalle het boere egter genoodsaak om meer produktiewe boerdery partyke te implementeer in ‘n poging om steeds voldoende volumes skaap- en lamsvleis te produseer. Produksiefaktore insluited die verhoging in die aantal lammers per ooi wat bemark kan word, vinniger markgereedheid van lammers en meer optimale groei van lammers dra almal by tot ‘n verhoogde inkomstestroom met die gebruik van minder produserende diere. ‘n Voorgestelde strategie tot verbeterde produksie is om lam-oorlewering te verbeter asook om lamgroei te verbeter. ‘n Tweede benadering is om deur middel van die optimalisering van melkproduksie en -kwaliteit deur die ooi, meer spesifiek die optimalisering van kolostrumproduksie en -kwaliteit deur middel van die voorsiening van byvoeding tydens die laat dragtigheisperiode. Laasgenoemde het ten doel om passiwe immuniteit na die lam te verhoog en uiteindelik lammortaliteit te verlaag. Om in Suid-Afrika volhoubaar met skaap en lammers te boer, moet skaapprodusente deurentyd boerderypraktyke aanpas en verbeter om sodoende ‘n bydrae tot werkgeleedhede en voedselsekerheid te kan maak. Die doelwitte vir hierdie studie was om die effek van hoër deurvloeiproteïen inname van ooie tydens laat dragtigheid op kolostrumkwaliteit, -viskositeit, lam-oorlewering en -groei, asook die effek van al die bogenoemde op ekstensiewe (Meatmaster) en intensiewe (Dohne Merino) skaaprasse te bepaal. Die eerste deel van hierdie studie het die effek van verskillende deurvloeiproteïenvlakke in die voer op kolostrumproduksie en -kwaliteit asook die lam grootmaakvermoë van ooie bepaal. Die twee vlakke van deurvloeiproteïen wat gebruik is, was 220 g/kg en 400 g/kg van totale ruproteïen. Die raseffek oor hoe die voedingstowwe toegedeel word vir produksie is verder ondersoek. Gedurende die 11 weke proeftydperk is die produksie van 18 Meatmaster (MM) en 18 Dohne Merino (DM) ooie vergelyk. Daaglikse droëmateriaal inname (DMI), en weeklikse massa toename van die ooie is gebruik om die gemiddelde daaglikse toename (GDT) en voeromsetverhouding (VOV) te bepaal. Bloedmonsters is 1 week voor lam, tydens lam en 1 week na lam geneem om sodoende die totale proteïen, albumien, globulien, albumien:globulien verhouding en ALP ensieme in die ooie se bloedplasma oor tyd te kon kwantifiseer. Kolostrummonsters is 1h,10h en 18h nadat die ooi gelam het geneem om kolostrum kwaliteit e bepaal. Melkmonsters is op 2, 4 en 6 weke na lam geneem om die samestelling van die melk in die drie stadiums van laktasie te kwantifiseer. Die deurvloeiproteïen vlakke van die voer wat tydens laat dragtigheid gevoer is, het geen effek op DMI, GDT en VOV van ooie in hierdie studie gehad nie. Die ooi ras het egter wel ‘n invloed op die somatiese selteliing (SST), bottervet-, totale vastestowwe-, laktoseinhoud en melk ureum stikstof (MUN) gehad. Die 22% deurvloeiproteïenvoer het beter 18h kolostrum geproduseer deur hoër imminoglobiliene G (IgG), totale proteïen asook ‘n hoër viskositeit te produseer. Melk wat deur die MM ooie geproduseer is, het ‘n hoër bottervetinhoud oor al drie stadiums van laktasie bevat. Die melk wat deur die DM ooie geproduseer is, het ʼn hoër SST gehad in die 4-weke-na-lam melkmonster. Geen verskille in uier of speen afmetings van die ooie is egter tussen behandings waargeneem nie. Ter afsluiting, het ooiras ‘n beperkte effek op melkproduksie gehad terwyl die vlakke van deurvloeiproteïenvlak tydens laat dragtigheid gevoer kolostrum- en melkproduksie slegs matig beïnvloed het. Die tweede deel van hierdie study was om te bepaal of die ooi se kolostrum- en melkproduksie ‘n invloed op voorspeengroeiprestasie en pasiewwe immuniteit van lammers het. Vier verskillende behandelings is gebruik; Meatmaster lammers gebore van ooie met die 22 % deurvloeiproteïen tydens laat dragtigheid (22%MM), Dohne Merino lammers gebore van ooie met die 22 % deurvloeiproteïen tydens laat dragtigheid (22%DM), Meatmaster lammers gebore van ooie met die 40% deurvloeiproteïen tydens laat dragtigheid (40%MM) en Dohne Merino lammers gebore van ooie met die 40% deurvloeiproteïen tydens laat dragtigheid (40%DM). Gedurende die 7 weke na lam tydperk is lammers weekliks geweeg om weeklikse massatoename en gemiddelde daaglikse toename (GDT) te bepaal. Bloedmonsters is geneem om die sukses van die serum imminoglobiliene G (IgG) te kon bepaal. Geen verskille, benewens die GDT van die 22%MM wat laer (P < 0.05) as die 40%DM was, is tussen behandelings vir geboorte- en speenmassa van lammers waarneneem nie. Beduidende interaksie is wel vir geboortemassa, GDT en speenmassa van lammers tussen die onderskeie 4 behandings waarnegeem. Laat dragtigheiddieet het nie lambloedserum IgG of speenounderdom beïnvloed nie. Die ras van die ooi het ook nie speenouderdom of lambloedserum IgG beïnvloed nie. Ten slotte het die invloed van deurvloeiproteïenvlak van die dieet tydens die laat dragtigheisperiode op kolostrum- en melkkwalitiet van die ooi lamproduksie weinig beïnvloed. Die resultate van die huidige studie dui daarop dat 22 % deurvloeiproteïen tydens die laat dragtigheidsperiode van ooie voldoende vir beide Meatmaster en Dohne Merino ooie wat in intensiewe hokke lam te wees, aagesien min verskille ten opsigte van enige van die vektore op ooi- of lamprestasie waargeneem is. In samevatting blyk dit dus dat daar geen voordeel getrek kan word om die deurvloeiproteïen vlak hoër as 22 % van totale ruproteïen aan laat dragtige ooie te voorsien nie.
Description
Thesis (MScAgric)--Stellenbosch University, 2024
Keywords
Citation